Advances in One-Dimensional Metal Sulfide Nanostructure-Based Photodetectors with Different Compositions

Abstract

One-dimensional (1D) nanomaterials have attracted considerable attention in the fabrication of nano-scale optoelectronic devices owing to their large specific surface areas, high surface-to-volume ratios, and directional electron transport channels. Compared to 1D metal oxide nanostructures, 1D metal sulfides have emerged as promising candidates for high-efficiency photodetectors due to their abundant surface vacancies and trap states, which facilitate oxygen adsorption and dissociation on their surfaces, thereby suppressing intrinsic carrier recombination while achieving enhanced optoelectronic performance. This review focuses on recent advancements in the performance of photodetectors fabricated using 1D binary metal sulfides as primary photosensitive layers, including nanowires, nanorods, nanotubes, and their heterostructures. Initially, the working principles of photodetectors are outlined, along with the key parameters and device types that influence their performance. Subsequently, the synthesis methods, device fabrication, and photoelectric properties of several extensively studied 1D metal sulfides and their composites, such as ZnS, CdS, SnS, Bi₂S₃, Sb₂S₃, WS₂, and SnS₂, are examined. Additionally, the current research status of 1D nanostructures of MoS₂, TiS₃, ReS₂, and In₂S₃, which are predominantly utilized as 2D materials, is explored and summarized. For systematic performance evaluation, standardized metrics encompassing responsivity, detectivity, external quantum efficiency, and response speed are comprehensively tabulated in dedicated sub-sections. The review culminates in proposing targeted research trajectories for advancing photodetection systems employing 1D binary metal sulfides.

1. Introduction

Over recent decades, low-dimensional nanomaterials have attracted considerable research interest across diverse domains, including electronics, optoelectronics, bioimaging, and photonic systems, owing to their readily tunable structural, electronic, optical, and chemical characteristics [1,2,3]. These materials are categorized into zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D) systems based on their structural dimensionality. Precise dimensionality control allows for the systematic modulation of their physical constraints, thereby regulating their dimensional scales and surface-to-volume ratios, while fundamentally determining their distinctive optical, thermal, electronic, and mechanical properties [4,5,6,7,8,9,10]. Among these materials, one-dimensional (1D) nanomaterials exhibit unparalleled advantages for photodetection applications. Nanowires (NWs), nanorods (NRs), and nanotubes (NTs) not only inherit the intrinsic benefits of low-dimensional systems but also amplify light–matter interactions through their anisotropic geometry, enabling directional carrier transport and enhanced light trapping [11,12,13,14,15]. In recent years, these materials have attracted considerable attention within the photonics community, particularly demonstrating critical functionalities in photocatalysis, solar energy conversion, and photodetection technologies. These distinctive attributes establish one-dimensional nanostructures as highly promising architectures for addressing the inherent constraints of traditional photodetection systems [16,17,18].

As critical signal transduction components, photodetectors exhibit extensive applicability in fiber-optic communications, advanced imaging systems, environmental sensing, and space exploration technologies, while demonstrating transformative potential for next-generation optical data storage and binary switching operations within integrated optoelectronic architectures [19,20,21,22,23]. Traditional photodetectors based on Si [24] and InGaAs [25], while technologically mature, are limited by their narrow spectral response ranges (Si: 300–1100 nm; InGaAs: 800–1700 nm), high dark current densities (>10⁻⁷ A cm⁻²), and rigid substrate constraints. These limitations hinder their compatibility with emerging requirements for flexible electronics and broadband detection applications. While metal oxide nanostructures (e.g., ZnO, TiO₂, Ga₂O₃) [26,27,28,29,30,31,32,33,34,35,36] emerged as alternatives by offering morphological controllability, their wide bandgaps (~3.3 eV) and surface vacancy deficiencies fundamentally restrict their light absorption efficiency and carrier dynamics [37,38,39,40]. In comparison, metal sulfides possess bandgap engineering potential through controlled sulfur stoichiometry tuning, enabling wide-spectrum photon absorption across extended wavelength regimes [41]. For example, CuS exhibits superior photoresponsivity (0.41 A W⁻¹) [42] and a microsecond-level response time, significantly outperforming Cu₂S (0.22 A W⁻¹, second-level response) [43]; stoichiometric modulation from SnS₂ to SnS enables continuous bandgap tuning from 2.9 eV to 1.32 eV, thereby achieving ultraviolet-to-near-infrared spectral response coverage (UV-NIR, ~300–1300 nm) [44]. Additionally, surface sulfur vacancies serve as effective electron trapping sites, which suppress carrier recombination and facilitate efficient carrier separation, consequently reducing dark current densities (<10⁻¹⁰ A cm⁻²) [45,46,47]. This synergistic interplay—spectral tunability coupled with recombination suppression—establishes metal sulfides as having enhanced optoelectronic capabilities relative to their conventional semiconductor and metal oxide counterparts. Some representative demonstrations of these capabilities include the following: CdS nanowires achieve exceptional UV–visible photoresponsivity (10⁴ A W⁻¹), outperforming ZnO nanowires by two orders of magnitude, while SnS₂-based heterostructures demonstrate broad-spectrum detectivity surpassing 10¹³ Jones, comparable to commercial InGaAs photodetectors. The unique advantage of 1D architectures originates from their inter-dimensional synergy between structural confinement and compositional engineering. Distinct from 2D planar configurations or 0D quantum-confined architectures, the anisotropic morphology of 1D systems concurrently reduces charge migration pathways and extends recombination lifetimes—a dimensional contradiction resolved through directional confinement modulation [48,49,50,51]. For example, 1D SnS₂ nanostructures demonstrate a specific detectivity of 10¹⁶ Jones and a responsivity of 10³ A W⁻¹, surpassing SnS₂-based quantum dots (10¹¹ Jones, 0.1 A W⁻¹) and thin films (2.02 × 10¹⁰ Jones, 1.95 A W⁻¹) by several orders of magnitude [44,52]. Meanwhile, 1D WS₂ photodetectors exhibit a responsivity of 0.777 A W⁻¹, which is 10 times higher than their thin-film counterparts (0.314 A W⁻¹) [53,54].

While current reviews focus primarily on 2D material systems, this work proposes a systematic classification of 1D metal sulfides via sulfur stoichiometry modulation (mono-, di-, and polysulfides), providing a novel analytical paradigm for elucidating structure–property relationships in photodetection physics. This review systematically examines synthesis methodologies for one-dimensional metal sulfides and their engineered composites (including doping strategies, p-n/n-n heterojunction configurations), with representative material systems spanning ZnS, CdS, SnS, WS₂, SnS₂, MoS₂, ReS₂, Sb₂S₃, Bi₂S₃, In₂S₃, and TiS₃. The enhanced optoelectronic performance of these devices is systematically assessed through key figures of merit—responsivity (R), detectivity (D*), external quantum efficiency (EQE), and temporal response dynamics. The concluding section delineates prospective research directions for 1D metal sulfide photodetectors, addressing fundamental scientific challenges alongside application-specific optimization strategies. This analysis establishes a methodological framework for guiding functional optoelectronic materials development.

This review establishes a pioneering framework elucidating how structural superiority synergistically interacts with sulfur-mediated electronic engineering to achieve unprecedented photodetection performance benchmarks. We perform critical techno-scientific evaluations of cutting-edge advances in quasi-1D transition metal sulfide systems (ZnS, CdS, SnS, WS₂, etc.). Departing from conventional fragmented approaches to synthesis protocols and device physics, this investigation establishes systematic correlations between morphological/compositional engineering and device-level performance metrics—responsivity (A W⁻¹), specific detectivity (Jones), external quantum efficiency (%), and temporal response characteristics.

2. Photoelectric Detector Basic Principle and Performance Parameters

2.1. Basic Principles of Photoelectric Detectors

A photodetector is formally defined as an optoelectronic transducer demonstrating photoconductivity modulation within photoactive media under photon irradiation. Its configuration primarily consists of two functional elements: a photon-sensitive semiconductor matrix and metallic charge transport electrodes. The operational dynamics are predominantly dictated by interface potential barrier formation at Schottky junctions and specific device configurations. These mechanisms can include the photoconductivity effect [55,56], the photovoltaic effect [57,58], the photo-thermoelectric effect [59,60], and the pyroelectric effect [61,62], among others. Photon absorption with energy surpassing the detector’s bandgap triggers electronic transitions from valence to conduction bands, generating mobile charge carriers. Under intrinsic built-in or externally applied electric fields, these liberated electrons undergo directional long-range transport, while concomitant hole migration through valence band states enhances bulk conductivity. The resultant electron–hole pair dissociation enables electrode-collectable photocurrent generation, demonstrating intensity-proportional behavior relative to incident photon flux at operational wavelengths. Subsequent sections will systematically evaluate critical performance metrics encompassing photocurrent density, spectral responsivity (R), normalized detectivity (D*), external quantum efficiency (EQE), and temporal response dynamics.

2.2. Basic Performance Parameters of Photodetector Devices

To enable rigorous performance comparison across photodetector architectures, standardized evaluation metrics have been established. This section delineates their formal definitions and elucidates the physical principles governing these fundamental photodetection parameters.

2.2.1. Photocurrent (I_ph)

I_ph is defined as the ratio of photogenerated electron–hole pairs (e⁻-h⁺) collected by the electrode at the edge of the semiconductor. In a photodetector, the photocurrent is estimated by the following equation [63,64,65]:

$$I_{ph}=I_{light}-I_{dark}$$

(1)

where I_ph denotes the photocurrent, and I_light and I_dark are the currents obtained by the device under light and dark conditions, respectively.

2.2.2. Responsiveness (R)

R denotes the photoelectric conversion efficiency of the photodetector. It is usually calculated using the following formula [63,64,65]:

$$R={\displaystyle \frac{I_{ph}}{PS}}={\displaystyle \frac{I_{light}-I_{dark}}{PS}}$$

(2)

I_ph is the photogenerated current, which refers to the current of the photodetector device under light (I_light) minus the current in the dark (I_dark), P is the incident light power density, and S is the effective area of light irradiation.

2.2.3. Specific Detection Rate (D*)

D* denotes the sensitivity of the photodetector device for low-signal detection and is defined as the reciprocal of the Noise Equivalent Power (NEP). NEP is the incident optical power at a signal-to-noise ratio of 1, i.e., the noise current i divided by R. D* can be expressed as follows [63,64,65]:

$$D^{*}={\displaystyle \frac{{(S∆f)}^{1/2}}{NEP}}={\displaystyle \frac{R{(S∆f)}^{1/2}}{i}}$$

(3)

where Δf is the bandwidth. When the dark current of the device is the main contributor to the noise, D* can be simplified as follows:

$$D^{*}={\displaystyle \frac{R}{{(2e{I}_{dark}/S)}^{1/2}}}$$

(4)

2.2.4. External Quantum Efficiency (EQE)

EQE is the average value of the number of electrons released by a photodetector device for each incident photon, and it is related to the wavelength of the incident light (I). EQE can be calculated by the following formula [63,64,65]:

$$EQE={\displaystyle \frac{N_C}{N_I}}={\displaystyle \frac{hc}{e\lambda }}R$$

(5)

N_C and N_I denote the number of photogenerated carriers and incident photons, respectively.

2.2.5. Response Time (τ)

The response speed of a photodetector is a characterization of how quickly a detector responds to light, and it is usually measured by the response time. The response time of a detector is usually the time it takes for the output signal to rise from zero to 63.2% of the peak (i.e., 1-1/e) or from the peak to 36.8% of the peak (i.e., 1/e) under the irradiation of pulsed light. It is also possible to take 10% to 90% of the rising edge of the detector’s optical impulse response curve as the rise time (t_r), or 90% to 10% of the falling edge as the falling time (t_f). In general, there are two main aspects that limit the response speed of a detector: (1) the resistance–capacitance-induced RC delay time; (2) the transit time of photogenerated carriers between electrodes. The response time can be approximated as follows [66]:

$$\tau =\sqrt{{{\tau }_{RC}}^2+{{\tau }_{tr}}^2}$$

(6)

where ${\tau }_{RC}$ is the circuit RC delay and ${\tau }_{tr}$ is the carrier time. In addition, for devices with parasitic photoconductance, the capture and release of photogenerated carriers by defects will also seriously affect the response speed of the device.

2.2.6. Photoconductivity Gain (G)

G is defined as the number of carriers passing through the external circuit corresponding to each incident photon in the photodetector device, and can also be calculated from the ratio of the carrier lifetime (${\tau }_l$) to the inter-electrode transition time (${\tau }_1$), which gives rise to a gain when the carrier lifetime is greater than the transition time. G can be calculated according to the following equation [63,64,65]:

$$G={\displaystyle \frac{{\tau }_l}{{\tau }_1}}={\displaystyle \frac{{\tau }_l}{d^2}}\mu V$$

(7)

where d is the distance between the two electrodes, μ is the mobility of the majority charge carriers, and V is the applied voltage.

2.2.7. Carrier Capture Coefficient (c)

In semiconductor device physics, the carrier capture coefficient (typically denoted as c or σ) is a key parameter that describes the efficiency of defects, traps, or impurity centers in capturing carriers (electrons or holes) in the material. It directly relates to the dynamics of carriers and influences the electrical characteristics of the device, such as response speed, dark current, and noise. The rate equation for carrier capture by defects is given by [67]:

$$R_{capture}=c·N_t·n$$

(8)

where $R_{capture}$, $N_t$, $n$, and $c$ are, respectively, the capture rates, defect state density, free carrier concentration, and capture factor.

When introducing the carrier thermal velocity ($v_{th}$), the capture coefficient can be expressed as follows:

$$c=\sigma ·v_{th}$$

(9)

$\sigma$: Capture cross-section, reflecting the “effective capture area” of defects.

$v_{th}$: Carrier thermal motion velocity, it is related to temperature ($v_{th}\propto \sqrt{T}$).

2.2.8. Linear Dynamic Range (LDR)

The linear dynamic range (LDR(λ)) of a photodetector is defined as the range across which the photocurrent rises with an increasing optical power of incident light. The detector can detect the incident signal within this range of optical power. The device’s responsiveness should ideally stay consistent as light intensity increases. Typically, the whole dynamic range is calculated from the NEP of a photodetector to the optical power when photocurrent saturates. It is often expressed in decibels (dB). The LDR(λ) can be represented (in dB) as follows [63,64,65]:

$$LDR\left(\mathsf{\lambda }\right)=20{log}_{10}{\displaystyle \frac{{P\left(\mathsf{\lambda }\right)}_{max}}{{P\left(\mathsf{\lambda }\right)}_{min}}}$$

(10)

where P(λ)_max and P(λ)_min are denoted as the highest and lowest limits of optical power in a certain wavelength range. Notably, having a suitably high LDR(λ) means being able to retain continuous sensitivity from strong-light to weak-light conditions, which is a necessity for weak-light sensing.

2.3. I-V Characteristics in Relation to Ohmic Contacts and Schottky Barriers

Current–voltage (I-V) characterization serves as a fundamental diagnostic tool for probing charge transport mechanisms in semiconductor architectures. The curve profile constitutes a critical indicator of interface quality and carrier injection dynamics between electrode–semiconductor interfaces. Nonlinear I-V characteristics reveal energy-filtering Schottky barrier signatures, whereas linear behavior demonstrates barrier-free Ohmic contact formation.

2.3.1. Schottky Barrier and Nonlinear I-V Curves

The Schottky barrier formation originates from interfacial energy-level misalignment between metallic work functions and semiconductor electron affinities. This energetic discrepancy induces localized band bending at the junction, generating a rectifying potential barrier that restricts majority carrier transport, thereby manifesting nonlinear charge injection behavior in I-V characteristics [68]. The observed asymmetric nonlinearity in Au/ZnSe/Au devices’ I-V characteristics confirms their Schottky-type interfacial characteristics at their electrode–semiconductor interfaces, as opposed to non-Ohmic charge injection pathways [69]. As shown in Figure 1a, a typical Schottky barrier I-V curve demonstrates that, under forward bias, current increases rapidly with voltage, while under reverse bias, current is significantly suppressed [70].

2.3.2. Ohmic Contact and Linear I-V Curves

Ohmic contacts are characterized by minimal interfacial resistance at metal–semiconductor interfaces, facilitating unrestricted majority carrier injection across the junction while exhibiting linear current–voltage characteristics. This optimized electronic state originates from energy-level alignment between metal work functions and semiconductor Fermi energies under thermodynamic equilibrium conditions [72]. For example, the linear I-V curve in Cr/Au electrode contacts with ITO nanowires confirms high-quality Ohmic contact formation [73]. As illustrated in Figure 1b, a typical Ohmic I-V curve demonstrates efficient current transport even at low voltages, thereby optimizing device performance [71].

Table 1. Work functions of different electrode materials.

Electrode Material	Work Functions (eV)	Contact Type	I-V Curve Features	Ref.
Au	5.1	Schottky contact	Nonlinear	[74]
Cr	4.5	Ohmic contact	Linear	[75]
ITO	4.4–4.5	Quasi-Ohmic contact	Close to linear	[75]

presents the work functions of different electrode materials and their corresponding I-V curve characteristics.

2.3.3. Comparison of Electrode Contact Configurations

The optimization of contact geometries in photodetectors requires engineering electrode–semiconductor interface configurations to optimize critical performance parameters encompassing responsivity, response speed, external quantum efficiency (EQE), and specific detectivity (D*) [76,77]. As illustrated in Figure 2, three primary contact configurations are typically employed: conventional (planar) contacts, interdigitated contacts, and hybrid contact structures [78]. This strategic selection of contact geometry enables performance enhancement through optimized carrier collection efficiency and reduced parasitic resistance.

Additionally, the work function and interfacial characteristics of different electrode materials (e.g., Au, Cr, ITO) significantly influence the selection of contact geometry [72,74].

Table 2. Performance characteristics of ZnSe-based MSM UV photodetectors with different Schottky contacts. Reprinted with permission from Ref. [78]. Copyright 2024, Pleiades Publishing.

Type of Contacts	Dark Current, nA (15 V)	Rejection Rate (15 V)	Responsivity, A W−1 (15 V)	Photo-Conductivity Gain (15 V)	Detectivity, cm W−1 HZ1/2 (15 V)
MSM, conventional Cr/Au	0.71	5.4 × 103	1.25	~14	8.3 × 1010
MSM, interdigitated Cr/Au	1.64	4.2 × 103	2.23	~26	9.9 × 1010
MSM, conventional Ni/Au	0.59	4.1 × 103	0.79	~9	5.8 × 1010
MSM, interdigitated Ni/Au	0.82	2.0 × 104	5.40	~62	3.4 × 1011
MSM, hybrid Ni/Au and Ag-NW	0.36	5.0 × 103	0.58	~7	5.5 × 1010

systematically compiles the performance metrics of ZnSe-based MSM UV photodetectors with varied contact geometries and electrode compositions under standardized operating conditions. The tabulated data reveal that discrete contact architectures incorporating different metallic electrodes demonstrate statistically significant performance discrepancies across key device parameters [78]. The interdigitated Ni/Au electrode configuration achieves a photoresponsivity of 5.4 A W⁻¹, demonstrating a two-fold enhancement over its Cr/Au counterpart (2.23 A W⁻¹). Conversely, conventional Cr/Au contacts exhibit superior performance (1.25 A W⁻¹) compared to standard Ni/Au architectures (0.79 A W⁻¹). This electrode-material-governed polarity inversion demonstrates the pivotal role of contact geometry optimization in precisely modulating photodetector operational parameters, thereby expanding their functional versatility within next-generation optoelectronic architectures.

2.4. Self-Biasing Behavior of Photodetectors

The self-biasing operation of photodetectors manifests as spontaneous photocurrent generation through the efficient separation and transport of photogenerated charge carriers under zero-external-bias conditions (V = 0 V). This phenomenon fundamentally originates from built-in potential gradients within device architectures, predominantly established at heterointerfaces or p-n junction boundaries. Under photon illumination, photogenerated carriers undergo field-driven separation via these intrinsic potential gradients, thereby enabling the photodetectors’ self-powered photodetection functionality.

2.4.1. Formation of Built-In Electric Field

The formation of built-in electric fields originates from carrier diffusion dynamics and space charge redistribution driven by Fermi-level gradients across p-n heterojunctions, culminating in thermodynamic equilibrium through band potential alignment and field stabilization [79,80]. As shown in Figure 3, when p-type Bi₂Se₃ and n-type Bi₂S₂ come into contact, electrons diffuse from the n-type (higher Fermi level) to the p-type (lower Fermi level) region, while holes diffuse in the opposite direction due to the Fermi-level mismatch. This process generates a space charge region proximal to the interface: positively charged donor ions are immobilized within the n-region, while negatively charged acceptor ions localize in the p-region. Thermodynamic equilibrium is established upon Fermi-level alignment across the interface, culminating in a stabilized built-in electric field [81,82].

2.4.2. Charge Separation and Transport Mechanism

The charge separation process is critical in photodetectors, with its efficiency directly determining device performance. As illustrated in Figure 4a, when photons irradiate the material surface, energy is transferred to electrons within the material. Excited electrons transit from the valence band to the conduction band, generating electron–hole pairs. Simultaneously, the built-in electric field induces band bending at the heterojunction or p-n junction interface. Electrons diffuse from the higher-energy conduction band material to the lower-energy counterpart, while holes migrate in the opposite direction through the valence band. Finally, a self-powered mode is formed [83,84,85]. When an external electric field is applied (Figure 4b), carriers are ultimately collected by electrodes: electrons accumulate near the ITO electrode (~4.8 eV) and holes enrich around the Ag electrode (~4.26 eV). This spatial separation reduces carrier recombination and enhances charge collection efficiency, enabling high-performance photodetection [86].

3. High-Performance Metal Sulfide-Based Photodetectors

3.1. Material Selection

Metal sulfide compounds constitute an extensive class of inorganic materials that have become a subject of intensive investigation for diverse emerging optoelectronic applications, including photodetectors, solar cells, and light-emitting diodes [87]. These compounds are present in the form of natural minerals such as sphalerite (ZnS), galena (PbS), and pyrite (FeS₂), which are inexpensive, abundant, and have different structural types [88]. Metal and sulfur elements, via distinct coordination configurations, yield structurally simple metal sulfides, while these compounds demonstrate remarkable diversity in both architectures and polymorphic crystalline phases, including isotropic/anisotropic arrangements and centrosymmetric versus non-centrosymmetric structural motifs [89]. One-dimensional metal sulfides exhibit significantly higher surface-to-volume ratios than their layered counterparts, facilitating superior optoelectronic performance via increased carrier densities and broad spectral sensitivity extending from ultraviolet (UV) to near-infrared (NIR) regimes. These compounds inherently support the classification of photodetectors into UV, visible, and NIR operational categories according to their intrinsic bandgap energetics. Wide-bandgap systems such as ZnS and SnS₂ are employed for UV detection, while visible-responsive compounds including CdS, WS₂, Sb₂S₃, MoS₂, and ReS₂ operate within the 400–700 nm range. Narrow-bandgap variants like TiS₃, SnS, and In₂S₃ facilitate NIR photodetection. Furthermore, metal sulfides are categorized as monosulfides (ZnS, CdS, SnS), disulfides (SnS₂, WS₂, MoS₂, ReS₂), or polysulfides (Sb₂S₃, In₂S₃, TiS₃), each exhibiting distinct structural and device property variations.

Table 3. Crystal structure, semiconductor type, resistivity, carrier mobility, and carrier concentration of various metal sulfide nanostructures.

Material	Crystal Structure	Bandgap (eV) Direct- Indirect-		Type of Conductivity	Electrical Resistivity (Ω·cm)	Carrier Concentration (cm−3)	Carrier Mobility (cm2/v·s)	Ref.
ZnS	Cubic	3.7	~	n-type	1.79 × 103	6.04 × 1019	90	[91,92,93,94]
CdS	Hexagonal	2.4	~	n-type	8.11 × 10−2	2.96 × 1020	14.5	[95,96,97]
SnS	Orthorhombic	1.32	1.09	p-type	5.4 × 103	10 17	37.75	[98,99,100]
WS2	Hexagonal	2.1	1.35	n-type	5 × 104	1018~1019	50	[101,102,103]
MoS2	Hexagonal	1.9	1.3	n-type	8.59 × 104	1014~1015	0.5–17	[104,105,106,107]
SnS2	Trigonal	2.9	2.1	n-type	1.2 × 102	5.43 × 1017	230	[108,109]
ReS2	Triclinic	1.5	~	n-type	2~5	1019	16–30	[110,111,112]
Sb2S3	Orthorhombic	1.78	~	n-type	1.3 × 104	7.3 × 1013	6.4	[113,114,115]
Bi2S3	Orthorhombic	1.3	~	n-type	7 × 103	1017~1020	~	[116,117,118]
In2S3	Hexagonal	2.0	~	n-type	38.8	3.8 × 1015	42.3	[119,120]
TiS3	Monoclinic	1.1	~	n-type	2~6	~	80	[121,122,123]

lists the important structural, optical and electrical properties of various metal sulfide nanostructures, materials whose superior structural, optical, and electrical properties have attracted considerable interest from researchers for high-performance photodetectors [90]. In the next section, we discuss in detail the progress of research on one-dimensional metal sulfide-based photodetectors.

3.2. One-Dimensional Binary Metal Sulfide-Based Photodetectors

This chapter systematically examines contemporary developments in one-dimensional metal sulfide photodetectors, beginning with the fundamental optoelectronic properties and device implementations of ZnS, CdS, and SnS monosulfide nanostructures, along with their heterojunction architectures. The discussion subsequently expands to transition metal disulfides (WS₂, SnS₂, MoS₂, ReS₂), analyzing their photodetection performance metrics and unique electronic configurations. Eventually, we highlight the superior optoelectronic conversion characteristics of higher-sulfur-content compounds, including Sb₂S₃, Bi₂S₃, and In₂S₃, establishing an expanded material selection framework and fundamental references for developing advanced photodetection systems. This comprehensive review aims to guide researchers towards a deeper understanding of the direction of one-dimensional metal sulfide-based photodetectors and inspire them to innovate in this field.

3.2.1. Photodetectors Based on a Single Sulfur–Metal Compound

One-dimensional metal monosulfide compounds exhibiting 1:1 metal–sulfur stoichiometric ratios have emerged as frontrunners in photodetector technologies. Notably, ZnS-based ultraviolet (UV) detectors and CdS-based visible-light photodetectors have attracted significant scientific focus, owing to their facile synthetic routes synergized with superior optoelectronic metrics, such as enhanced photosensitivity and ultrafast response dynamics. Although SnS research remains comparatively underdeveloped, with fewer mature fabrication protocols relative to analogous systems, the unique optoelectronic signatures arising from its intrinsic p-type semiconducting nature reveal significant opportunities for engineering advanced p–n heterojunction photodetection platforms.

Zinc Sulfide (ZnS)-Based Photodetectors

As an important constituent of the metal–sulfur group of compounds, ZnS exhibits a bandgap energy of 3.72 eV (sphalerite) or 3.77 eV (fibrillar zincite) [124,125]. Devices prepared with the compound find primary applications in the domains of lasers, photocatalysis, flat panel displays, and UV photodetectors [126,127,128]. This section methodically delineates contemporary scientific progress in one-dimensional ZnS nanostructured photodetectors, encompassing systematic classifications of pristine ZnS-based configurations, doped variants, and heterojunction architectures within photodetection systems.

ZnS nanostructures demonstrate ultrafast UV photoresponse characteristics, attributed to their wide bandgap energy, enhanced electron mobility, and superior electrical conductivity. Building upon these findings, Sue et al. [129] fabricated ZnS NWs on p-type Si substrates via thermochemical vapor deposition (TCVD), subsequently constructing photodetectors with sputter-deposited Pt electrodes. The optimized devices exhibited notable optoelectronic performance under 365 nm UV illumination (38 mW/cm²), achieving a photocurrent gain of 0.572, a responsivity of 2.761 A W⁻¹, and a response speed with rise/recovery times of 3.2/3.6 s. However, intrinsic deep-level defects in ZnS NWs have been identified as critical mediators of substantial carrier scattering phenomena during charge transport dynamics, thereby inducing progressive degradation in their photoluminescence quantum yield. Following this rationale, Dai’s team [130] developed a CVT (chemical vapor transport) strategy to grow single-crystalline ZnS nanowires with reduced defect density on Au-coated sapphire substrates, subsequently constructing nanophotonic devices through the precise integration of individual nanowires with Au interdigitated electrodes. The synthesized nanowires demonstrated superior crystallinity and pronounced photoluminescence characteristics. The systematic evaluation of single-nanowire UV detectors under dark conditions and 325 nm illumination (Figure 5a) revealed a ten-fold photocurrent enhancement compared to dark current levels. Device optimization at 1 V bias with 325 nm excitation (1.25 mW cm⁻²) yielded exceptional performance metrics, including the maximum switching ratio and sub 100 ms response dynamics (Figure 5b), collectively confirming the viability of defect-engineered ZnS nanowires for high-performance UV photodetection applications.

In comparison to nanowire structures, nanotubes exhibit a greater surface-area-to-volume ratio, which allows for enhanced light absorption and reflection in optoelectronic devices. Consequently, An et al. [131] successfully synthesized single-crystalline ZnS nanotubes (NTs) on Au-catalyzed Si substrates via a vapor-phase deposition process. Complementing this synthesis, the team fabricated metal–semiconductor–metal (MSM) photodetector architectures by integrating silver nanowire (Ag NW) networks as transparent electrodes through microinjection patterning. Under −2 V bias, the optimized devices exhibited a high photocurrent of 1.32 μA and an ultralow dark current of 8.44 pA, yielding an exceptional switching ratio (~1.56 × 10⁵) and rapid response dynamics (rise/decay times: 0.12 s/0.4 s) (Figure 5c,d). At 40 mW cm⁻² illumination intensity, these ZnS NT-based devices demonstrated superior optoelectronic performance in the following metrics: responsivity (16.5 A W⁻¹), photoconductive gain (8.92), detectivity (1.41 × 10⁹ Jones), and ultralow Noise Equivalent Power (0.0001 pW Hz⁻¹/²). This enhanced functionality originates from their nanotubular morphology, where confined photon trajectories and interfacial electric fields synergistically boost light–matter interactions and charge separation efficiencies. The research team further developed an innovative self-powered ZnS-NT/Si-NW MSM UV photodetector and systematically evaluated its optoelectronic performance [132]. The device exhibits pronounced photovoltaic functionality under zero-bias conditions, arising from the built-in interfacial electric field at the Ag/ZnS heterointerface. Under optical excitation, photoinduced electron–hole pairs in ZnS experience field-driven directional separation and transport dynamics: electrons are preferentially transported to the Ag nanowire collector electrode via drift–diffusion mechanisms, while holes remain spatially confined within the ZnS matrix, collectively establishing a sustained photogenerated current. This inherent self-driven carrier management mechanism facilitates bias-free photocurrent generation through optimized charge partitioning and transport kinetics. In self-powered mode, the device achieves a dark current of 14.9 pA and a photocurrent of 0.29 μA, yielding a substantial switching ratio of 19,173. Figure 5e depicts five repeat cycles under on/off switching illumination. It can be seen that the device can be alternatively switched between on- and off-state conditions with excellent reproducibility and stability—exhibiting rapid rise/decay times of 0.09 s/0.07 s (ambient) and 0.19 s/0.10 s (vacuum) under pulsed illumination (Figure 5f). Under 297 nm UV irradiation (40 mW cm⁻²), the detector delivers a responsivity of 2.56 A W⁻¹, a photoconductive gain of 13.6, and a detectivity of 1.67 × 10¹⁰ Jones, establishing a foundational framework for designing high-efficiency 1D ZnS-based photodetection systems.

The ordered architecture of nanoarray configurations demonstrates significant advantages over isolated nanostructures through enhanced light-harvesting capabilities derived from expanded active areas. Liang et al. [133] employed metal–organic chemical vapor deposition (MOCVD) to fabricate vertically aligned ZnS nanoarrays (NWAs) on GaAs substrates. Figure 6a schematically depicts the single-nanowire device architecture, wherein Cr/Au electrodes are lithographically defined at both terminals of individual ZnS nanowires on silicon substrates. An analogous fabrication strategy was employed for the nanowire array (NWA) configuration, incorporating conformally deposited Au thin-film electrodes across the NWA surface (Figure 6b). Systematic photoelectronic characterization under 325 nm illumination quantitatively revealed divergent operational parameters: the individual nanowire device exhibited a photocurrent of 1.5 pA under 10 V applied bias (Figure 6c), whereas the NWA architecture generated a 508 pA photocurrent with substantially suppressed dark current at an applied bias of only 1 V (Figure 6d). Spectral selectivity testing at 442 nm confirmed minimal visible-light response, affirming its UV-specific detection capabilities. Cyclic switching stability measurements (Figure 6e,f) were conducted to quantify the temporal response characteristics. The nanowire array (NWA) device demonstrated superior reproducibility, operational stability, and significantly accelerated response speeds (t_r = 5 ms, t_f = 40 ms) compared to the single-nanowire device (t_r, t_f < 1.5 s), as evidenced by five consecutive illumination on/off cycles. The optimized NWA photodetector achieved exceptional figures of merit, including 1.87 A W⁻¹ responsivity and 710% external quantum efficiency. This performance enhancement mechanism is mechanistically attributed to two synergistically coupled mechanisms: (1) interwire coupling phenomena that effectively suppress nonradiative recombination pathways; (2) vertically ordered nanoarchitectures acting as resonant photonic microcavities that enable enhanced photon localization through multi-scale light–matter interactions. When integrated with ultralow operational voltage thresholds and wafer-scale manufacturing protocols, these rationally designed nanoarray systems establish technologically promising platforms for implementing next-generation energy-autonomous optoelectronic device systems.

Nanostructured ZnS with atomic-level crystallinity and mitigated compensated defect pairs manifests a highly insulating nature, thereby imposing critical constraints on its optoelectronic device integration capabilities. Strategic doping emerges as an effective approach to modulate these properties, as demonstrated by Saeed et al. [134] through their hydrothermal synthesis of Mn²⁺-doped ZnS nanorods (NRs). The team fabricated UV photodetectors by integrating silver electrode networks via radio-frequency magnetron sputtering. Doping-induced bandgap narrowing (3.46 eV vs. 3.77 eV for pristine ZnS) extended the spectral response while maintaining visible-blind UV selectivity. As shown in Figure 7a, the device exhibited a 310 nm UV-triggered photoresponse with 1.8 A W⁻¹ responsivity and 719% external quantum efficiency at 0.1 V bias under 0.5 W cm⁻² illumination. Figure 7b demonstrates the time-dependent photoresponse characteristics of the UV photodetector. The photocurrent maintained remarkable stability, with an average value of 145.5 μA over hundreds of illumination cycles. Upon UV light termination, the photocurrent rapidly decayed to its low-current state, indicating excellent repeatable stability under operational conditions. The device achieved fast response dynamics (rise/decay times of 16 ms/1.1 ms), with this enhancement attributed to Mn²⁺-induced surface dangling bonds that accelerated carrier recombination through defect-mediated pathways. Additionally, Jiang et al. [135] synthesized n-type Al-doped ZnS nanowires through thermal co-evaporation, with indium tin oxide (ITO) electrodes deposited via pulsed laser deposition (PLD) to fabricate photodetector devices. As demonstrated in Figure 7c, these devices exhibit wavelength-dependent photocurrent enhancement under 100 mW cm⁻² illumination, achieving UV-region detection currents equivalent to visible-range dark current magnitudes. At optimized Al doping (ZnS:Al = 10:1 molar ratio) under 5 V bias with 254 nm illumination (300 mW cm⁻²), the detectors demonstrated record responsivity (3.1 × 10⁶ A W⁻¹) and photoconductive gain (1.5 × 10⁷). Their enhanced performance stems from two synergistic mechanisms: (1) Surface-band bending, promoting the spatial separation of photogenerated carriers. (2) Aluminum dopants acting as hole-trapping sites, suppressing carrier recombination and extending lifetime (t ≈ 445 s). While exhibiting prolonged response times (t_r = 153 s, t_f = 445 s) compared to their Mn²⁺-doped counterparts, attributed to delayed hole release from Al-induced trapping sites, the exceptional UV responsivity and gain characteristics of these detectors compensate for the temporal limitations in their non-switching detection applications.

Surface passivation and heterojunction engineering have been proven to be effective in enhancing photoresponsive performance by mitigating nonradiative trap states. Zhang et al. [136] synthesized ZnS/InP core–shell nanowires (NWs) via chemical vapor deposition (CVD) and fabricated photodetectors by lithographically patterning Cr/Au electrodes on individual NWs aligned on Si/SiO₂ substrates. As shown in Figure 7d, when light irradiates a material, it generates photogenerated carriers (electron–hole pairs). The number of these carriers is proportional to the incident optical power. As the optical power increases, the number of generated carriers increases, leading to an enhanced photocurrent. Carrier generation scales linearly with incident power (1.87 μW cm⁻²), where heterostructured devices exhibit 18.7 times higher photocurrents than pristine ZnS NWs. Under 323 nm UV illumination at 5 V bias, the heterojunction demonstrates 295 A W⁻¹ responsivity and a 10.9 pA photocurrent—two orders of magnitude greater than undoped ZnS NWs (2.0 A W⁻¹, 0.1 pA). The optimized device achieves a photoconductive gain of 1.10 × 10³ and a detectivity of 1.65 × 10¹³ Jones. Figure 7f displays the I-T curves measured under different bias voltages of 2 V, 5 V, and 8 V. The corresponding I-T curves under all the tested biases exhibit excellent reproducibility and stability, further confirming the superior performance of the ZnS/InP NW heterostructure-based device. At 5 V bias, the device demonstrates rapid response characteristics, with a rise time (t_r) of 0.75 s and a decay time (t_f) of 0.5 s. Complementary to these approaches, Lou et al. [137] fabricated 1D ZnS/CdS nanowire heterostructures via a two-step thermal evaporation process, subsequently patterning Cr/Au bilayer electrodes through lithographic microfabrication. The photodetector demonstrates broadband spectral operation with a photocurrent of 1.2 nA and dark current of 10 fA at 450 nm (213 μW cm⁻²), achieving an exceptional current switching ratio (~1.2 × 10⁵). Concurrently, the device exhibits ultrahigh detectivity (2.23 × 10¹⁴ Jones) and rapid temporal response characteristics (rise/fall times: 5 ms/7 ms), establishing a benchmark for dual-band UV-vis ultrafast detection. Advancing UV optoelectronics, Lee et al. [138] engineered ZnS/ZnO core–shell nanorods through dual-zone horizontal tube furnace synthesis and atomic layer deposition (ALD). This architecture exhibits enhanced near-band-edge (NBE) UV emission by suppressing deep-level (DL) defects through interfacial energy band alignment. The improved performance results from synergistic carrier transport between the ZnS core and ZnO shell, which amplifies UV radiative recombination while passivating surface trap states. This work provides critical insights into the development of high-efficiency UV photodetectors with suppressed visible-wavelength interference.

Cadmium Sulfide (CdS)-Based Photodetectors

As an intrinsic n-type semiconductor, CdS exhibits unique electronic properties characterized by a wide direct bandgap (~2.4 eV), elevated refractive index, reduced work function, and efficient charge carrier transport [139,140,141]. These inherent attributes have enabled CdS nanomaterials to function as critical components in diverse optoelectronic systems, including optical actuators, photonic waveguides, field-effect transistors (FETs), light-emitting diodes, and radiation detectors [142,143,144]. This sub-section systematically reviews recent progress in one-dimensional CdS nanostructure-based photodetection technologies, with a particular focus on comparative performance analyses of undoped, chemically modified, and heterojunction-engineered device architectures.

Hierarchical CdS nanowire (NW) architectures exhibit superior surface-to-volume ratios, photon-harvesting efficiency, and charge transport dynamics compared to their conventional single-crystalline counterparts [145,146]. Li et al. [147] synthesized branched CdS NWs through vapor transport synthesis and fabricated a photodetector device via the lithographic patterning of Cr/Au electrodes onto individual NWs aligned on SiO₂/Si substrates. As shown in Figure 8b, the photocurrent exhibits intensity-dependent behavior under 470 nm illumination (0.93 mW cm⁻²). When light irradiates a material, it generates photogenerated carriers (electron–hole pairs). The number of these carriers is proportional to the incident optical power. As the optical power increases, the number of generated carriers increases, leading to an enhanced photocurrent. At 5 V bias, the device achieves an ultralow dark current (4.7 fA) and a high photocurrent (92.2 pA), yielding a switching ratio of 1.96 × 10⁴ with detectivity reaching 4.27 × 10¹² Jones. Figure 8c displays the dynamic photocurrent response of the monolayer CdS nanowire photodetector under a 2 V bias voltage. The photocurrent rapidly increases to a steady state upon illumination and decays promptly after light cessation, revealing the device’s superior response speed and operational stability. Figure 8d presents a magnified view of a single cycle from Figure 8c, with a measured rise time (t_r) and decay time (t_f) of 0.3 s and 0.4 s, respectively.

To mitigate gate bias effects and suppress dark current generation, Zheng et al. [148] fabricated single CdS nanowire (NW) devices via chemical vapor deposition (CVD), integrating Cr/Au electrodes through metal evaporation and patterning. A 200 nm ferroelectric P(VDF-TrFE) polymer layer was spin-coated onto the NW channel (Figure 9a), inducing carrier depletion via polarization-generated electrostatic fields. Post-depletion, the device exhibited a dark current of 10⁻¹² A and a photocurrent of 1.13 μA under 375 nm UV illumination (18 mW cm⁻²), yielding an ultrahigh switching ratio (~10⁶). This performance enhancement stemmed from suppressed hot-electron tunneling currents, enabling photon-driven carrier dominance. The optimized device demonstrated exceptional performance in the following metrics: photoconductive gain (8.6 × 10⁵), responsivity (2.6 × 10⁵ A W⁻¹), and detectivity (2.3 × 10¹⁶ Jones) at 0.01 mW cm⁻² bias. Temporal response analysis (Figure 9c) revealed rapid dynamics, with 12.6 ms rise and 180 ms decay times. Complementarily, Zhao et al. [149] synthesized low-defect CdS nanorods (NRs) on SiO₂/Si substrates via CVD, fabricating Ti/Au-electrode photodetectors through lithography. The devices exhibited exceptional blue-light sensitivity (450 nm, 0.5 mW cm⁻²), with responsivity peaking at 1.23 × 10⁴ A W⁻¹ (Figure 9d). Further performance benchmarks included an external quantum efficiency of 3.5 × 10⁶%, a detectivity of 2.8 × 10¹¹ Jones, and response/recovery times of 0.82/0.84 s.

Self-powered photodetectors, capable of achieving optoelectronic conversion and detection without an external power supply, demonstrate significant potential for energy-efficient applications. Chai et al. [150] synthesized core–shell Sb/CdS nanowires through a two-step chemical vapor deposition (CVD) process, and the device architecture is illustrated in Figure 10a. The single NW-based PDs were prepared by photolithography, thermal evaporation, and stripping processes at both ends of a single NW on a Si/SiO₂ substrate in order to construct Cr/Au source/drain electrodes. The device boasts superior photocurrent performance, and Figure 10b presents the increasing photocurrent and built-in open-circuit voltage with rising light intensity at different light intensities for 470 nm illumination. Figure 10c exhibits the time-dependent photoresponse of the device in self-powered mode at a 700 nm wavelength. The photocurrent remains virtually unchanged even after hundreds of switching cycles, demonstrating remarkable stability and reproducibility. It exhibits excellent stability and reproducibility with a substantially enhanced photocurrent (12.85 pA) versus dark current (45.5 fA), achieving a high on/off current ratio of 3.54 × 10³. Its better optical response speed is demonstrated by the single optical on/off cycle transient response in Figure 10d, whose rise time and recovery time are less than 0.384 s and 0.312 s, respectively. Also, the device has high optical R, D*, and G values of 93.62 A/W, 2.33 × 10¹⁴ Jones, and 2.47 × 10² under illumination at the above wavelength with 0 V bias and a power of 19.12 μW/cm², respectively, demonstrating excellent detection performance.

Conventional photodetectors relying solely on photovoltaic effects exhibit limited functionality in cryogenic environments due to their significantly degraded response at low temperatures. To address this limitation, Chang et al. [151] engineered a SnS/CdS heterojunction photodetector synergizing pyroelectric (temperature-induced polarization changes generating transient currents [152]) and photovoltaic effects. The device architecture comprised hydrothermally grown CdS nanorod arrays on FTO glass, overlaid with thermally evaporated SnS films and Au electrodes (Figure 11a). Temperature- and power-dependent analyses (Figure 11b) reveal enhanced pyroelectric currents with increasing optical power (0.08 mW cm⁻²) and decreasing temperature (300 → 130 K), demonstrating the effective substitution of carrier migration (photocurrent) with lattice-vibration-driven currents (pyroelectric) for low-temperature operation. Figure 11c quantifies this transition, showing pyroelectric dominance (Ipyro/Iphoto ratio increasing from 10% to 400%) under cryogenic, low-irradiance conditions. At 650 nm illumination, the device achieves 10.4 mA W⁻¹ responsivity and 3.56 × 10¹¹ Jones detectivity at zero bias, with sub 30 ms response/decay times. Complementing this approach, Ren et al. [86] developed self-powered p-n heterojunction detectors through the hydrothermal deposition of n-CdS nanorods onto p-Si substrates, capped with sputtered ITO/Ag electrodes. The devices exhibit a broadband response (405–1064 nm), with 64.8 mA W⁻¹ responsivity and 1.31 × 10¹⁰ Jones detectivity at 2.55 mW cm⁻², alongside rapid 190.8/298.4 μs response/recovery dynamics under zero bias. These dual-mechanism architectures establish new paradigms for extreme-environment photodetection systems.

To investigate the influence of heterojunction interfacial structures on the optoelectronic performance of devices, our research team fabricated a photodiode (Figure 12a) by constructing head-to-head PANI/CdS p-n heterojunction nanowire arrays with ITO/Au composite electrodes [153]. The device exhibited excellent rectification characteristics and diode behavior, demonstrating high sensitivity in the visible spectrum, particularly at 420 nm. As shown in Figure 12b, the rectification ratio of the PANI/CdS heterojunction nanowire array reached 34.1 under 5.21 mW cm⁻² illumination, representing a three-fold enhancement compared to the dark-state ratio (11). Repeatability and response speed are critical parameters for evaluating a photodetector’s ability to track rapidly varying optical signals. Figure 12c illustrates the switching cycle performance under 420 nm illumination, where the device exhibited a dark current of 0.21 μA and a photocurrent of 1.23 μA, achieving an on/off ratio of 5.8 with high stability and repeatability. The rapid response dynamics arise from the high surface-to-volume ratio of the PANI/CdS heterojunction nanowires, coupled with surface defects and dangling bonds that act as recombination centers, accelerating free carrier recombination and thereby reducing decay time. We also regulated device performance by constructing heterointerfaces with diverse morphologies, including PTCM (poly{3-thiophene carboxylic acid methyl ester})/PbS axially deeply inserted heterojunction nanowire arrays with enlarged interfacial areas, which exhibited superior performance, with a switching ratio of up to 83.5 [154]. To achieve infinite interfacial contact and enhance carrier separation efficiency, we synthesized homogeneous CdS/PPV (poly(p-phenylene vinylene)) hybrid nanowire arrays (NWAs) via porous anodic aluminum oxide (AAO) template-assisted electrochemical co-deposition. Prior to deposition, Au electrodes were sputtered onto one side of the AAO template, followed by ITO glass coating to fabricate novel photodetectors [155]. Compared to pure-CdS nanowire arrays, the CdS/PPV hybrid NWAs demonstrated a significantly enhanced photoresponse. As shown in Figure 12d, under 545 nm illumination at 4.2 mW/cm², the current increase in the homogeneous device (schematic in Figure 12d inset) far exceeded that of pure-CdS-based devices. The CdS/PPV hybrid NWA device exhibited a stable photocurrent over multiple light on/off cycles, with a dark current of 0.027 μA at a 5 V bias and a stabilized photocurrent of 1.457 μA under illumination, achieving an exceptional switching ratio of 53.4 (Figure 12e), approximately 17 times higher than those of pure-CdS devices (2.8). This improvement primarily stems from PPV acting as a bridge to consume or transfer photogenerated holes and electrons, thereby suppressing electron–hole recombination and enhancing the photoresponse. Under the same illumination, Figure 12f shows that the device’s on/off ratio significantly increased with rising light intensity across a bias range of −5 V to +5 V, confirming the suitability of CdS/PPV hybrid NWAs for 545 nm green-light detection. Based on these findings, we systematically summarized and analyzed recent advances in sulfide-based photodetectors and p-n heterojunction self-powered devices. Additionally, by optimizing the preparation of ZnO nanorod arrays, we established a solid foundation for future studies on ZnO-template-based sulfide photodetectors [63,156].

To extend the spectral detection range of CdS-based devices, Rani et al. [157] synthesized TiO₂/CdS nanorod heterostructures via hydrothermal synthesis, fabricating UV photodetectors with spin-coated Ag electrodes. The devices exhibit an exceptional photocurrent-to-dark current ratio of 439.66 (Figure 13a), enabled by ultralow dark currents, which enhance detection sensitivity. Under 365 nm illumination, responsivity and external quantum efficiency (EQE) peak at 2.865 A W⁻¹ and 971.36%, respectively, at 40 μW cm⁻² (Figure 13b,c). The anomalous EQE >100% arises from synergistic interfacial phenomena: built-in electric fields in the heterojunction, Type-II band alignment prolonging carrier lifetimes, and suppressed recombination through graded band structures [158]. This performance is further quantified by a Noise Equivalent Power of 3.64 × 10⁻⁹ W Hz⁻¹/² and a detectivity of 9.90 × 10¹² Jones. Temporal response profiling (Figure 13d) reveals rapid dynamics, with a 0.99 s rise time and a 0.49 s decay time. These results underscore bandgap-engineered heterostructures as critical enablers of broadband, high-performance photodetection systems.

Tin Sulfide (SnS)-Based Photodetectors

SnS is a bandgap-tunable p-type semiconductor material with indirect and direct bandgap energies of approximately 1.0–1.3 eV and 1.3–1.5 eV, respectively [159,160]. It exhibits well-tuned conductance, high carrier mobility, and wide wavelength absorption. This allows SnS to be employed in a multitude of applications, including field-effect transistors, spin-valley lasers, and photodetectors [161,162,163].

P-type SnS nanowires (NWs) hold critical importance for constructing advanced p-n heterostructures. Zheng et al. [164] fabricated p-type SnS NWs via chemical vapor deposition (CVD), transferring individual NWs onto SiO₂/Si substrates. Electron-beam lithography defined the drain/source contacts, followed by the thermal evaporation of Cr/Au electrodes to complete the photodetector assembly. The device exhibits an optical gain of 2.8 × 10⁴ under 830 nm illumination (0.05 mW cm⁻²), coupled with remarkable responsivity (1.6 × 10⁴ A W⁻¹) and detectivity (2.4 × 10¹² Jones). Temporal response profiling reveals ultrafast dynamics with a 1.2 ms rise time and 15.1 ms decay time. The asymmetric response kinetics likely originate from trap-mediated carrier dynamics, where surface states or defect centers delay trapped carrier release, extending excess charge persistence.

In a separate study, Chen et al. [165] synthesized p-type SnS nanowires (NWs) with uniform nano-scale diameters via chemical vapor deposition (CVD), transferring them onto SiO₂/Si substrates for device fabrication. Thermally evaporated Cr/Au electrodes were patterned to construct photodetectors, which demonstrated high responsivity (2.6 × 10² A W⁻¹), photoconductive gain (3.9 × 10²), and detectivity (1.8 × 10¹³ Jones) under 830 nm illumination (0.12 mW cm⁻², 1 V bias). The devices exhibited ultrafast response dynamics, with rise and decay times of 9.6 ms and 14 ms, respectively. This enhanced performance originated from the NWs’ reduced diameter and exceptional crystallinity, which minimized surface defects and established efficient carrier transport pathways, thereby accelerating generation–recombination kinetics. These results highlight the potential of low-dimensional p-type SnS architectures for next-generation photodetectors requiring high sensitivity, rapid response, and energy-efficient operation.

Comparative Analysis

This section systematically reviews synthesis methodologies and performance characteristics of one-dimensional (1D) monosulfide-based photodetectors. Comparative analysis reveals that nanotube architectures with hollow-core geometries surpass their nanowire/nanorod counterparts in photodetection efficiency, attributable to the enhanced light trapping through their tubular cavity resonance effects. For instance, ZnS nanotube (NT) devices demonstrate superior responsivity (16.5 A W⁻¹ vs. 2.761 A W⁻¹ for nanowires) and photocurrent generation (508 pA). Ferroelectric polymer-polarized CdS nanowire detectors achieve ultralow dark currents (10⁻¹² A) through carrier depletion mechanisms, yielding exceptional detectivity (2.6 × 10¹⁶ Jones) exceeding conventional structures by 2–4 orders of magnitude. Strategic doping substantially modulates semiconductor conductivity, exemplified by Al-doped ZnS detectors exhibiting record responsivity (3.1 × 10⁶ A W⁻¹) and photoconductive gain (1.5 × 10⁷). Heterojunction engineering simultaneously reduces interfacial recombination via built-in electric fields while lowering carrier injection barriers, enabling ultrafast response dynamics. The ZnS/CdS nanowire heterostructure exemplifies this dual functionality, achieving broadband UV-vis detection (2.23 × 10¹⁴ Jones) through complementary bandgap alignment. Notably, SnS/CdS composite detectors demonstrate cryogenic operability by coupling photovoltaic and pyroelectric effects, attaining 10.4 mA W⁻¹ responsivity and 3.56 × 10¹¹ Jones detectivity under low-temperature conditions.

Table 4. Synthesis methods of 1D monosulfide metal compounds and their photodetector properties.

Material	Contact Electrodes	Methodology	Wavelength Power	Responsivity (A/W)	Detectivity (Jones)	EQE (%)	Rise Time Fall Time	Photo-I Dark-I	Ref.
ZnS NWs	Pt	TCVD	365 nm 38 mW/cm2	2.761	~	0.572	3.2 s 3.6 s	~	[129]
ZnS NWs	Au	CVT	325 nm 1.25 mW/cm2	~	~	~	<0.1 s	~	[130]
ZnS NTs	Ag	Thermal Evaporation	~ 40 mW/cm2	16.5	1.41 × 109	8.92	0.12 s 0.4 s	8.44 pA 1.32 μA	[131]
ZnS NTs	Ag	Thermal Evaporation	297 nm 40 mW/cm2	2.56	1.67 × 1010	13.6	0.09 s 0.07 s	14.9 pA 0.29 μA	[132]
ZnS NWA	Cr/Au	MOCVD	325 nm 16 mW/cm2	>1.87	~	>710	5 ms 40 ms	~ 508 pA	[133]
ZnS:Mn NRs	Ag	Hydrothermal	310 nm 0.5 W/cm2	1.8	~	719	16 ms 1.1 ms	~	[134]
ZnS:Al NWs	ITO	Thermal Co-Evaporation	254 nm 300 mW/cm2	3.1 × 106	~	1.5 × 107	153 s 445 s	~	[135]
ZnS/InP NWs	Cr/Au	CVD	323 nm 1.87 μW/cm2	295	1.65 × 1013	1.10 × 103	0.75 s 0.5 s	~ 10.9 pA	[136]
ZnS/CdS NWs	Cr/Au	Thermal Evaporation	450 nm 213 μW/cm2	~	2.23 × 1014	~	5 ms 7 ms	10 fA 1200 pA	[137]
CdS NWs	Cr/Au	Vapor Transfer	470 nm 0.93 mW/cm2	~	4.27 × 1012	~	0.3 s 0.4 s	4.7 fA 92.2 pA	[147]
CdS NWs	Cr/Au	CVD	375 nm 0.01 mW/cm2	2.6 × 105	2.3 × 1016	8.6 × 105	12.6 ms 180 ms	10−12 A 1.13 μA	[148]
CdS NRs	Ti/Au	CVD	450 nm 0.5 mW/cm2	1.2 × 104	2.8 × 1011	3.5 × 106	0.82 s 0.84 s	~	[149]
Sb/CdS NWs	Cr/Au	Two-Step CVD	470 nm 19.1 μW/cm2	93.62	2.33 × 1014	2.47 × 102	0.384 s 0.312 s	12.85 fA 45.5 pA	[150]
SnS/CdS NWA	Au	Hydrothermal-Thermal Evaporation	650 nm 0.08 mW/cm2	10.4 m	3.56 × 1011	~	<30 ms <30 ms	14.9 pA 0.29 μA	[151]
Si/CdS NRs	Ag	Hydrothermal	~ 2.55 mW/cm2	64.8 m	1.31 × 1010	~	190.8 μs 298.4 μs	~	[139]
PPV/CdS NWA	Au	Electrochemical Co-Deposition	545 nm 4.2 mW/cm2	~	~	~	~	0.027 μA 1.457 μA	[155]
TiO2/CdS NRs	Ag	Hydrothermal	365 nm 40 μW/cm2	2.865	9.9 × 1012	971.36	0.99 s 0.49 s	~	[157]
SnS NWs	Cr/Au	CVD	838 nm 0.05 mW/cm2	1.6 × 104	2.4 × 1012	~	1.2 ms 15.1 ms	~	[164]
SnS NWs	Cr/Au	CVD	830 nm 0.12 mW/cm2	2.6 × 102	1.8 × 1013	~	9.6 ms 14 ms	~	[165]

quantitatively benchmarks these performance metrics, establishing 1D monosulfide architectures as versatile platforms for extreme-environment photodetection technologies.

3.2.2. Photodetectors Based on Disulfide Metal Compounds

Transition metal disulfides exhibit superior optoelectronic characteristics, stemming from their unique crystallographic and electronic configurations. These materials demonstrate exceptional carrier mobility and ultrafast response dynamics, making them ideal for high-sensitivity photodetection systems—SnS₂ for UV-vis spectral ranges and WS₂ for visible–NIR regimes. Current disulfide-based photodetector research remains predominantly concentrated on lamellar MoS₂ and ReS₂ architectures at the two-dimensional (2D) level. However, 2D systems suffer from ambient instability and interfacial degradation under prolonged operational stresses, fundamentally limiting device longevity. In contrast, single-crystalline 1D disulfide nanostructures provide atomically smooth surfaces with minimal defect densities, enhanced surface-to-volume ratios, and intrinsic structural anisotropy along the longitudinal axis, which enables directional carrier transport with reduced scattering losses.

Selenium Sulfide (SnS₂)-Based Photodetectors

SnS₂, as a homodimeric derivative of SnS, emerges as an environmentally benign n-type semiconductor characterized by chemical stability and an indirect bandgap spanning 2.1–2.4 eV [166,167]. Its strong photoconductive response and superior visible-range absorption coefficients (α > 10⁵ cm⁻¹) have driven its extensive application in photovoltaics, photocatalytic systems, and broadband photodetection technologies [168,169,170].

To explore one-dimensional SnS₂ synthesis pathways and to improve SnS₂ applications, Zervos et al. [171], by investigating the conversion of SnO₂ to SnS₂ NWs, found that the tetragonal SnO₂ NW structure can be completely converted to a hexagonal SnS₂ NW structure at 400 °C. This represents a novel approach to the synthesis of SnS₂ NWs, and it paves the way for new avenues of research in the field of one-dimensional SnS₂-based photodetectors. Subsequently, Zheng et al. [172] synthesized n-type SnS₂ nanowires (NWs) via gas-phase deposition and spin-coated a ferroelectric polymer layer (polyvinylidene fluoride-trifluoroethylene, P(VDF-TrFE)) onto the NWs. Photodetectors were fabricated by depositing Cr/Au electrodes via vacuum thermal evaporation and vapor stripping, creating a localized ferroelectric polarization field (Figure 14a). Under a −17.2 V side-gate voltage, the device exhibited an ultralow dark current (3 × 10⁻¹³ A) and an elevated photocurrent (2.74 μA), achieving a switching ratio of 10⁷. This behavior arises from the ferroelectric polymer’s polarization, which induces the depletion of free electrons in the SnS₂ channel via a high-intensity electrostatic field. To evaluate photoresponse efficiency, the ferroelectric gate polarization was deactivated (voltage terminated post-activation), and the device was tested under 520 nm illumination with a 1 V bias (Figure 14b). Photoconductive gain and responsivity scaled with light intensity, reaching maxima of 4.0 × 10⁵ and 2.1 × 10⁵ A W⁻¹ at 0.06 mW cm⁻². Suppressed dark current noise enhanced detectivity to 1.3 × 10¹⁶ Jones. The time-resolved photoresponse was conducted under 520 nm illumination, shown in Figure 14c. The SnS₂ NW device exhibited good switching periodicity and stability, and its I_light/I_dark ratio was as high as 10⁷. The ferroelectric polarization effect further accelerated electron–hole pair dynamics, yielding rapid transient response characteristics with a 56 ms rise time and 91 ms decay time.

The inherent built-in electric fields within heterostructures drive the directional migration of photogenerated electrons and holes, forming depletion layers while leveraging bandgap disparities to broaden spectral absorption ranges, thereby significantly enhancing photoresponse and detection capabilities. Das et al. [173] fabricated Si/SnS₂ nanowire heterojunctions via hydrothermal synthesis, integrating Au/Al electrodes through thermal evaporation (Figure 14d). The devices demonstrated ultralow dark currents (2.86 × 10⁻¹² A at 0 V), surpassing their spin-coated SnS₂/Si counterparts (2 × 10⁻¹⁰ A) [174]. Under 340 nm illumination (20 nW mm⁻²), the detectors achieved exceptional responsivity (383 A W⁻¹) and external quantum efficiency (1.3 × 10⁵%), attributed to bias-activated (2 V) defect-state electron release, which induced multiplicative interface carrier generation and expanded photogeneration zones. Temporal response analysis (Figure 14f) revealed rapid 10–90% rise (0.55 s) and 90–10% decay (0.33 s) times, confirming superior response kinetics. These advancements position 1D SnS₂ heterostructures as promising candidates for next-generation UV-vis photodetection technologies.

Figure 14. Ferroelectric single-side door control SnS₂ NWs-based PD: (a) schematic, (b) photoconductor gain and responsivity at V = 1 V, (c) photocurrent response of the device under optical chopping (520 nm, 11 mW cm⁻²) at Vds = 1 V, without additional gate voltage. Reprinted with permission from Ref. [172]. Copyright 2021, Walter de Gruyter. Si/SnS₂ NWs heterojunction devices: (d) PD schematic, (e) I-V curve under logarithmic conditions, (f) time-resolved optical response, rise (t_r) and fall time (t_f). Reprinted with permission from Ref. [175]. Copyright 2021, American Institute of Physics.

Figure 14. Ferroelectric single-side door control SnS₂ NWs-based PD: (a) schematic, (b) photoconductor gain and responsivity at V = 1 V, (c) photocurrent response of the device under optical chopping (520 nm, 11 mW cm⁻²) at Vds = 1 V, without additional gate voltage. Reprinted with permission from Ref. [172]. Copyright 2021, Walter de Gruyter. Si/SnS₂ NWs heterojunction devices: (d) PD schematic, (e) I-V curve under logarithmic conditions, (f) time-resolved optical response, rise (t_r) and fall time (t_f). Reprinted with permission from Ref. [175]. Copyright 2021, American Institute of Physics.

Tungsten Sulfide (WS₂)-Based Photodetectors

One-dimensional WS₂, with similar hexagonal symmetry to the ZnS structure, is a direct bandgap semiconductor (1.3–1.95 eV) [176] which is widely used in photodiodes [177], photodetectors [178], and solar devices [179], among others. The high electron mobility, optical responsiveness, and luminescence-enhancing properties of one-dimensional WS₂ reveal potential promise for nanostructured devices and applications [180,181].

To investigate the light detection performance of photodetectors based on WS₂ nanotubes (NTs), Zhang et al. [54] synthesized WS₂ nanotubes (NTs) via hydrogen reduction and the sulfidation of WO₃ nanoparticles in a scalable fluidized bed reactor. Photodetectors were fabricated through electron-beam lithography and the thin-film deposition of Ti/Au electrodes onto individual WS₂ NTs aligned on SiO₂/Si substrates. The devices demonstrated wavelength-dependent photoresponses, exhibiting superior photocurrents under 633 nm illumination (532 W cm⁻², 0.5 V bias) compared to 785 nm excitation (600 W cm⁻²) (Figure 15a). Notably, the on/off ratio reached 336 under 633 nm (5.3 kW cm⁻²) illumination—ten-fold higher than the 32 ratio observed at 785 nm (6 kW cm⁻²). This disparity originates from 633 nm photons (1.96 eV) inducing direct bandgap transitions in WS₂ NTs, while 785 nm photons (1.58 eV) only activate indirect transitions. The devices achieved peak responsivity (2360 A W⁻¹) and external quantum efficiency (4.6 × 10⁶%) at 633 nm (0.5 V bias), with retained functionality in the near-infrared region (785 nm: 2.88 A W⁻¹, 454% EQE). The superior crystallinity of WS₂ NTs minimizes surface dangling bonds, effectively suppressing persistent charge trapping. Cyclic illumination testing at a 633 nm wavelength (Figure 15b) revealed ultrafast the response dynamics and cyclic stability of the devices, with precisely measured rise time (t_r = 256 μs) and decay time (t_f = 286 μs), as quantified in Figure 15c. The exceptional properties of organic materials—flexibility, optical transparency, and cost-effectiveness—have driven significant interest in organic–inorganic hybrid photodetection systems. Liu et al. [182] developed hybrid photodetectors by solution-processing a composite of WS₂ nanotubes (NTs) and poly(N-vinylcarbazole) (PVK), spin-coated onto Au-patterned SiO₂/Si substrates. Current-voltage (I-V) characterization under varied illumination (Figure 15d) revealed semiconducting behavior in the WS₂-PVK hybrid film, with nonlinear curves bypassing the origin, indicative of self-powered operation. Under 552 nm (0.8 mW cm⁻²) and 661 nm (0.2 mW cm⁻²) illumination, the device exhibited faster response dynamics (0.92 s rise/0.09 s decay) for green light compared to red light (2 s/3.34 s) (Figure 15e,f), correlating with enhanced shorter-wavelength absorption. At 0.06 mW cm⁻² (zero bias), the detector achieved 0.2 mA W⁻¹ responsivity and 2.23 × 10⁴ Jones detectivity. These results position WS₂ NT-based hybrids as promising platforms for visible/NIR high-speed photodetection and optical-switching applications.

In other works, Chaudhary and Khanuja [183] synthesized heterostructures based on MoS₂-NFs/WS₂-NRs using a hydrothermal technique and prepared a photodetector structure using a drop-casting technique with silver as the electrode; the schematic diagram is reported in Figure 16a. The photocurrents under different irradiation wavelengths are plotted in Figure 16b for an applied power supply of 12 V and a power of 50 mW/cm². As opposed to the photocurrents at 635 nm and 1064 nm (0.29 μA, 0.55 μA), the photocurrent can be as high as 0.75 μA at NIR (785 nm), and this high photocurrent gives the device an excellent photoresponse, with a value of 15 μA/W, demonstrating excellent near-infrared (785 nm) light sensitivity. The device also has the minimum near-infrared Noise Equivalent Power (16.89 × 10⁻⁶) under the above external conditions, which enables it to achieve the best detection performance. For example, the external quantum efficiency and specific detection rate have extremely high values compared to visible (635 nm) and far-infrared (1064 nm) light, as seen in Figure 16c,d, of 16.89 × 10⁻⁶% and 24 × 10⁶ Jones, respectively. In addition, the composite device has a response speed of 0.82 s/1.59 s. This suggests that the heterostructure can be used as a photodetector for broadband spectroscopy, especially in the near-infrared region.

Other Metal Disulfide (MoS₂, ReS₂)-Based Photodetectors

Despite advancements in layered MoS₂-based photodetectors, their suboptimal light absorption and complex fabrication processes have constrained their commercial viability. To address this, Gao et al. [184] successfully prepared high-purity n-type MoS₂ square nanotubes by a simple hydrothermal method and constructed a photodetector by spin-coating a solution containing MoS₂ nanotubes on a PET substrate and uniformly coating both ends of the nanotubes as electrodes with silver conductive paste. As illustrated in Figure 17a, when light is irradiated on MoS₂ nanotubes, the device exhibits excellent optoelectronic performance in the near-infrared (NIR) light band, which is mainly due to the fact that the surface of the nanotubes consists of nanosheets of S-vacancy-rich nanosheets, which provide high responsivity in the NIR region, and in addition, the unique luminal structure of the nanotubes also reflects and scatters the incident light multiple times and absorbs the incident light more completely. The I-V curves of the device at 915 nm under different optical powers are presented in Figure 17b, and the photocurrent is as high as about 2 μA at the same bias voltage when the light intensity reaches 100 mW/cm². Under fixed voltage and wavelength with varying optical power levels, the device maintains consistent dynamic photoresponse and initial current through multiple illumination cycles, demonstrating remarkable photoresponse reproducibility and exceptional operational stability (Figure 17c). Performing a high-resolution display of a switching cycle, as described in Figure 17d, the device shows a good optical response speed with a rise/recovery time value of 5.3 s/1.53 s. Its high photogenerated current and response speed enable the device to have excellent detection performance at a 915 nm near-infrared light wavelength (100 mW/cm² intensity), including an excellent photoresponse, specific detectivity, and external quantum effect, as shown in Figure 17e,f with the bias voltage gradually increasing to 3 V and values as high as 2.33 mA/W, 7.55 × 10⁸ Jones, and 3.33 × 10⁻¹%, and these results provide new possibilities for the development of novel one-dimensional MoS₂-based photodetectors.

Li et al. [185] fabricated MoS₂ nanotubes (NTs) on ITO substrates via anion-exchange synthesis, subsequently integrating Y-TiOPc nanoparticles (NPs) synthesized by microemulsion phase-transfer and p-TPD (N,N’-diphenyl-N,N’-di-p-toluylbenzidine) layers via spin-coating to form a photoactive heterostructure. Au electrodes were deposited via magnetron sputtering, yielding a Y-TiOPc/MoS₂ photodetector with a broadband UV-vis-NIR spectral response. Compared to pristine MoS₂ devices, Y-TiOPc-induced interfacial band bending enhances electron trapping and hole injection efficiency, significantly improving carrier generation, separation, and transport dynamics. At 20 V reverse bias under 0.01 mW cm⁻² illumination (365–850 nm), the device achieves peak responsivity (20,588 mA W⁻¹), external quantum efficiency (4947.6%), and detectivity (1.94 × 10¹² Jones). Notably, it demonstrates an ultrafast temporal response (134 ms rise/143 ms decay), surpassing conventional MoS₂ NT-based photodetectors in both speed and stability. In addition, Varshney et al. [186] synthesized β-Ga₂O₃ by thermally oxidizing a GaN epitaxial layer on a sapphire substrate, followed by sputter-depositing MoS₂ nanorods to form MoS₂/β-Ga₂O₃ heterojunctions. High-performance broadband (UV-vis-NIR) self-powered photodetectors were fabricated by patterning Pt electrodes via DC magnetron sputtering at both ends of the heterostructure, as schematically illustrated in Figure 18a. The devices exhibits ultralow dark currents of approximately 79 nA under dark conditions. The bias-dependent I-T characteristics were systematically evaluated under ultraviolet (266 nm) and near-infrared (950 nm) illuminations, with the applied biases ranging from 0.5 to 5 V and a constant optical power of 180 μW (Figure 18b,c). The devices maintained exceptional current stability and measurement reproducibility through multiple switching cycles under various environmental conditions. The maximum photocurrents and response speeds (t_r and t_f) reached 16.92 μA, 9.42 μA, 0.29/0.3 s, and 0.15/0.19 s, respectively. The disparity arose because 266 nm illumination required a longer duration for photogenerated carriers to excite from the valence band to the conduction band and establish photocurrent. Under a 5 V bias (Figure 18d), the devices exhibited power-dependent responsivity enhancement across a broadband UV-vis-NIR spectral range. At 266 nm UV illumination (30 μW cm⁻²), peak responsivity reached 42.11 A W⁻¹. Concurrently, the detectors achieved a specific detectivity of 3.2 × 10¹¹ Jones and an external quantum efficiency (EQE) of 1.97 × 10⁴% under identical conditions, maintaining high-performance detection from UV to NIR wavelengths (Figure 18e,f). These results demonstrate a viable pathway for developing broadband 1D MoS₂-based photodetectors with tailored spectral operability.

ReS₂ has emerged as a highly promising optoelectronic material [187], though current research predominantly focuses on its two-dimensional (2D) configurations, with investigations into one-dimensional (1D) ReS₂ architectures remaining scarce. Addressing this gap, An et al. [188] pioneered the synthesis of single-crystalline ReS₂ nanowires via chemical vapor deposition (CVD), fabricating photodetectors with Ag nanowire networks as transparent conductive electrodes. Under 3.0 V bias, the devices demonstrated substantial photocurrent switching ratios, with currents rising from 0.42 nA (dark) to 4.95 nA (illuminated). Temporal response analysis revealed rise and decay times of 1.8 s and 3.9 s, respectively, indicating competitive temporal response characteristics for emerging low-dimensional optoelectronics. To comprehensively assess the photodetection performance of the ReS₂ nanowire (NW)-based photodetectors (PDs), the devices were evaluated under both ambient and vacuum conditions under 500 nm illumination (0.42 nW cm⁻²). In air, the PDs achieved exceptional responsivity (5.08 × 10⁵ A W⁻¹), external quantum efficiency (EQE: 1.07 × 10⁶%), and specific detectivity (6.1 × 10¹⁵ Jones). Under vacuum, these metrics decreased to 2.03 × 10⁵ A W⁻¹ (Rλ), 4.3 × 10⁵% (EQE), and 6.1 × 10¹⁴ Jones (D*), respectively. This performance discrepancy is attributed to the absence of oxygen molecules in the vacuum, which suppresses surface oxygen adsorption and the associated electron scavenging, thereby promoting bulk carrier recombination. The superior optoelectronic metrics position ReS₂ NWs as leading candidates for next-generation high-performance nanostructured photodetectors.

Comparative Analysis

This section comprehensively examines photodetectors utilizing one-dimensional disulfide metal compounds, emphasizing structural design and performance optimization through comparative device analysis. Optimized nanostructures with tunable bandgaps and enhanced carrier mobility prove critical for achieving superior photodetection metrics. Notably, 1D disulfide architectures demonstrate unique broadband spectral responsivity, exemplified by chemically stabilized SnS₂ nanowire-based devices exhibiting exceptional UV-vis performance in the following metrics: responsivity (2.1 × 10⁵ A W⁻¹), external quantum efficiency (4.0 × 10⁵%), and detectivity (1.3 × 10¹⁶ Jones). Hollow-structured WS₂ nanotube detectors showcase visible-light specificity with ultrafast response dynamics (256 μs rise/286 μs decay), outperforming conventional nanowire systems by orders of magnitude. Heterostructured designs, such as thermally oxidized β-Ga₂O₃/MoS₂ configurations, achieve noise suppression (dark current: 79 nA) and accelerated response kinetics through interfacial band engineering. Single-crystalline CVD-grown ReS₂ nanowire detectors further highlight material potential with record metrics: 5.08 × 10⁵ A W⁻¹ responsivity, 6.1 × 10¹⁵ Jones detectivity, and 1.07 × 10⁶% EQE.

Table 5. Synthesis of one-dimensional metal disulfide compounds and their photodetector properties.

Material	Contact Electrodes	Methodology	Wavelength Power	Responsivity (A/W)	Detectivity (Jones)	EQE (%)	Rise Time Fall Time	Photo-I /Dark-I	Ref.
SnS2 NWs	Cr/Au	CVD	520 nm 0.06 mW/cm2	2.1 × 105	1.3 × 1016	4.0 × 105	56 ms 91 ms	3 × 10−13 A 2.74 μA	[172]
Si/SnS2 NWs	Au/Al	Hydrothermal	340 nm 20 nW/cm2	383	~	1.3 × 105	0.55 s 0.33 s	2.9 × 10−12 A ~	[173]
WS2 NTs	Ti/Au	High temperature	633 nm 532 W/cm2	2360	~	4.6 × 106	256 μs 286 μs	336 times lower	[54]
WS2 NTs-	Au	Solution synthesis	552 nm 0.06 mW/cm2	0.2 m	2.23 × 104	~	0.92 s 0.09 s	~	[182]
MoS2/WS2 NRs	Ag	Hydrothermal	785 nm 50 mW/cm2	15 μ	24 × 106	16.9 × 10−6	0.82 s 1.59 s	~	[183]
MoS2 NTs	Ag	Hydrothermal	915 nm 100 mW/cm2	2.33 m	7.55 × 108	3.33 × 10−1	5.3 s 1.53 s	~ 2 μA	[184]
Y-TiOPc/MoS2 NTs	Au	Anion exchange	365–850 nm 0.01 mW/cm2	20,588 m	1.94 × 1012	494,736	134 ms 143 ms	~	[185]
β-Ga2O3/MoS2 NRs	Pt	Magnetron sputtering	266 nm 30 μW/cm2	42.11	3.2 × 1011	1.97 × 104	0.29 s 0.3 s	79 nA 16.92 μA	[186]
ReS2 NWs	Ag	CVD	500 nm 0.42 nW/cm2	5.08 × 105	6.1 × 1015	1.07 × 106	1.8 s 3.9 s	0.42 pA 4.95 nA	[188]

systematically benchmarks these advancements, underscoring 1D disulfide architectures as transformative platforms for high-sensitivity, broadband photodetection technologies.

3.2.3. One-Dimensional Polysulfide Metal Compound-Based Photodetectors

Variations in sulfur stoichiometry induce substantial structural and functional divergences in metal sulfide compounds. In contrast to low-sulfur-content materials like ZnS and SnS₂, higher-sulfur-stoichiometry systems such as Sb₂S₃, Bi₂S₃, and In₂S₃ (metal-to-sulfur ratio 2:3) exhibit reduced bandgap energies (<2 eV), rendering them ideal for broadband spectral photoconversion with accelerated carrier dynamics. Beyond bandgap modulation, increased sulfur content enhances crystallinity, which passivates surface defects and optimizes charge transport. These synergistic effects significantly elevate device performance metrics, particularly carrier mobility and temporal photoresponse characteristics.

Indium Sulfide (In₂S₃)-Based Photodetectors

Butanov’s group [189] synthesized In₂S₃ nanowires on Au-catalyzed Si/SiO₂ substrates via atmospheric-pressure chemical vapor transport (AP-CVT), fabricating single-nanowire photodetectors through photolithographic patterning and thermal evaporation of Cr/Au electrodes. These devices exhibited ultralow dark currents (9.95 nA at 1 V bias), enabling superior photoresponsive behavior. Under 405 nm illumination (2 W cm⁻²), they achieved a switching ratio of 11.3, with responsivity and external quantum efficiency (EQE) reaching 16.01 A W⁻¹ and 4903%, respectively, demonstrating robust photovoltaic conversion capabilities.

In addition, Xie and Shen [190] synthesized single-crystalline In₂S₃ nanowires via chemical vapor deposition (CVD), fabricating flexible photodetectors by lithographically patterning Au/Ni source/drain electrodes on individual nanowires transferred to PET substrates (3D schematic: Figure 19a). These devices demonstrated pronounced visible-range photoresponses, exhibiting strong wavelength-dependent photocurrent generation (300–600 nm, Figure 19b). Under 450 nm illumination (176.7 W cm⁻²), photoinduced carrier multiplication significantly enhanced the photocurrent to 293 nA at 5 V bias, yielding an exceptional switching ratio (~10⁶) relative to the dark current (0.29 pA). Photoresponsivity and external quantum efficiency (EQE) peaked at 7.35 × 10⁴ A W⁻¹ and 2.28 × 10⁷% (400 nm, 5 V bias), respectively, with concurrent detectivity reaching 2.4 × 10¹⁴ Jones (Figure 19c), establishing In₂S₃ nanowires as high-performance flexible photodetection platforms. Moreover, the devices demonstrate highly stable and reproducible characteristics under different bias voltages. The time-dependent photoresponse of the detectors, as shown in Figure 19d, was measured by toggling 450 nm light illumination with a 10 s on/off cycle. Under a constant optical power density of 177 μW/cm² and different bias voltages (2 V, 4 V, and 8 V), the current values remained nearly identical to their initial magnitudes, demonstrating highly stable and reproducible characteristics across all three operational conditions. After repeating the switching many times, the photocurrent and the dark current were almost at the same level as in the initial state, and the photoresponse time and the attenuation time were only 6.5 ms/9.5 ms, an excellent photoresponse speed. When the devices were bent at bend angles from 0° to 120°, the photocurrents generated were almost the same as that of the unbent state (0°). These results show that In₂S₃ NW devices have a promising future in the application of high-performance and wearable optoelectronic devices.

Antimony Sulfide (Sb₂S₃)-Based Photodetectors

Antimony sulfide (Sb₂S₃), an inorganic n-type semiconductor crystallizing in an orthorhombic system, possesses a direct bandgap ranging between 1.7 and 1.8 eV [191,192]. This unique combination of structural and electronic characteristics enables broad-spectrum photoresponsivity, spanning ultraviolet–visible to near-infrared regions, which has driven its versatile utilization across multiple technological domains. Its current applications encompass photovoltaic devices, photocatalytic hydrogen evolution, Li/Na/K-ion battery systems, photodetection architectures, and related advanced functional materials [193,194,195,196].

One-dimensional Sb₂S₃ nanostructures have garnered significant research interest, owing to their well-defined crystallinity, exceptional thermal stability, and enhanced optical absorption coefficients relative to other 1D nanomaterials [197]. In this context, Zhong et al. [198] synthesized Sb₂S₃ nanowires (NWs) on SiO₂/Si substrates via sulfur-assisted vapor-phase deposition, subsequently fabricating NW-based photodetectors through a sequence of lithographic patterning, the electron-beam deposition of Au source/drain electrodes, and lift-off processes. Under 638 nm illumination (1 V bias, 0.03 mW/cm² optical power), the devices demonstrated remarkable optoelectronic performance: an ultrahigh responsivity of 1.15 × 10³ A/W, a specific detectivity of 2 × 10¹³ Jones, and a low dark current of 2.0 × 10⁻¹⁰ A. At an elevated optical power (45.2 mW/cm²), a substantial photocurrent of 4.2 × 10⁻⁸ A was achieved, yielding an impressive switching ratio of 210. Temporal response characterization revealed rapid rise/fall times of 37/38 ms, confirming their efficient photo-switching capabilities. Concurrently, Zhao’s team [199] developed optically anisotropic quasi-1D Sb₂S₃ NWs on SiO₂/Si using sulfur-assisted gas-phase transport, integrating polarization-sensitive photodetectors via lithographically defined Au contacts. The optimized devices exhibited a maximum current on/off ratio of 69.6 under 450 nm illumination (2 V bias, 40 μW/cm²), coupled with a responsivity of 343.4 mA/W. At 520 nm excitation, ultrafast photoresponse dynamics were observed, with rise/fall times (t_r/t_f) of 470/680 μs, highlighting sub-millisecond operational speeds.

To mitigate surface-adsorbed impurities (e.g., metal–organic precursors, surfactants, and reducing agents) that degrade photodetector performance, Ye et al. [200] developed high-crystallinity Sb₂S₃ nanowires (NWs) on SiO₂/Si substrates via chemical vapor deposition (CVD). Individual NW devices were fabricated by thermally evaporating Ni/Au electrodes at both termini. As illustrated in Figure 20a, the devices exhibit broadband spectral responsivity (360–785 nm) under 28 mW/cm² illumination, with a peak photocurrent of 2.5 nA at 532 nm. This phenomenon arises from the bandgap of Sb₂S₃ being approximately 1.5–1.6 eV (corresponding to an absorption edge wavelength of ~600–700 nm). When the incident light wavelength is shorter than this critical wavelength (i.e., the photon energy exceeds the bandgap), the material efficiently absorbs photons and generates electron–hole pairs, leading to an enhanced photocurrent as the wavelength decreases (energy increases). When the wavelength exceeds 700 nm, the photon energy becomes insufficient to excite electronic transitions, causing a sharp decline in absorption efficiency and a significant reduction in photocurrent. At ultralow power (0.03 mW/cm², 5 V bias), the device demonstrates exceptional charge transport efficiency (responsivity: 65 A/W) and superior figures of merit—specific detectivity (2.1 × 10¹⁴ Jones), external quantum efficiency (1.5 × 10⁴%), and sensitivity (2.2 × 10⁴ Jones). Cyclic stability testing reveals < 15.6% photocurrent degradation after 10⁴ on/off cycles, coupled with rapid response dynamics (rise/fall times: 76/82 ms). Concurrently, Ma et al. [201] synthesized single-crystalline Sb₂S₃ NWs via atmospheric-pressure CVD on SiO₂/Si, integrating Ti/Au electrodes to construct polarization-sensitive UV-vis photodetectors. As illustrated in Figure 20b, the devices demonstrate excellent operational stability and reproducibility under an irradiation of 318 mW/cm², with the on/off ratio maintained at approximately 2800. At 635 nm (0.3 μW/cm²), they deliver an ultrahigh responsivity (270 A/W) and record external quantum efficiency (5.3 × 10⁴%) and specific detectivity (4.37 × 10¹³ Jones). Notably, the device exhibits ultrafast response/recovery kinetics (10/12 ms) and polarization-dependent photosensitivity at 405 nm, achieving a dichroic ratio of 7.2—a benchmark performance among low-dimensional polarized photodetectors.

To achieve precise control over crystallinity, purity, and defect density in Sb₂S₃ nanomaterials for high-performance photodetectors, Liu’s group [202] engineered single-crystalline Sb₂S₃ nanorods (NRs) with tunable aspect ratios via hydrothermal synthesis followed by H₂/Ar ambient thermal annealing. Photodetectors were fabricated through electron-beam deposition of Au electrodes onto Sb₂S₃ NRs arrays on SiO₂/Si substrates. Under 560 nm illumination (110 μW/cm²), the devices demonstrated a pronounced switching ratio of 109.8. As illustrated in Figure 20c,d, the photoresponse metrics exhibited an inverse correlation with optical power density, attributed primarily to enhanced carrier recombination losses at higher excitation intensities. At 0.038 mW/cm², the detector achieved peak performance parameters in the following metrics: responsivity (5.10 A/W), external quantum efficiency (1130.68%), specific detectivity (2.16 × 10¹⁰ Jones), and ultrafast response kinetics (rise/decay times: t_r/t_f = 4.03/4.08 ms). These results underscore the direct correlation between crystallographic perfection and enhanced optoelectronic functionality in nanostructured devices.

Tubular architectures demonstrate enhanced photon-harvesting efficiency compared to nanowire and nanorod configurations through their augmented light-trapping capabilities. Zhang et al. [203] prepared single-crystalline Sb₂S₃ microtubes via chemical vapor deposition (CVD). Despite micrometer-scale tube dimensions, the fabricated devices exhibited exceptional photoresponsivity under 808 nm laser illumination (8 V bias, 300 mW/cm²), achieving a photocurrent of 185 nA, a switching ratio of ~200, and rapid response/recovery times (t_r/t_f = 22/24 ms) in two-terminal measurements. The detector further demonstrated superior figures of merit—responsivity (8.5 mA/W), sensitivity (667 cm²/W), and specific detectivity (1.33 × 10⁶ Jones)—indicating the efficient charge transport mechanisms of Sb₂S₃ microtubes and providing foundational insights for tubular photodetector optimization. In a separate study, Chao et al. [204] developed Sb₂S₃ nanowire arrays (NWAs) on fluorine-doped tin oxide (FTO) substrates through a templateless solvothermal reflow process, constructing photodetectors via FTO overlayer deposition. At 0.5 V bias under 640 mW/cm² illumination, the devices exhibited 15.3-fold photocurrent enhancement (113.5 nA vs. dark current 7.4 nA). Rapid switching tests revealed sub-second response kinetics (rise/recovery: 0.52/1.1 s), underscoring the devices’ operational agility in dynamic light environments.

To enhance photodetector responsivity, Zhang et al. [205] engineered Au nanoparticle (NP)-functionalized Sb₂S₃ nanowires (NWs) through chemical vapor deposition (CVD) on silicon substrates. The NWs were transferred via contact printing to SiO₂/Si or flexible polyethylene terephthalate (PET) substrates, followed by Cr/Au electrode deposition using lithography and thermal evaporation. Au NPs were subsequently integrated by solution-phase deposition to fabricate rigid/flexible UV-vis detectors. As shown in Figure 21a, under 700 nm illumination (10 V bias, 510 μW cm⁻²), the Au-NP-modified rigid device exhibited a 286-fold photocurrent enhancement (163 nA vs. 57 pA for pristine NWs). Transient response analysis (Figure 21b,c) revealed retained rise times (0.2 s) but significantly accelerated recovery kinetics (0.3 s vs. 2 s for unmodified devices), demonstrating plasmon-enhanced charge extraction. The flexible variant maintained spectral parity with its rigid counterpart across 350–700 nm (Figure 21d), exhibiting peak white-light responsivity (59.5 A/W) and detectivity (4.29 × 10¹⁰ Jones) at 680 μW cm⁻². The dynamic testing of the device under a 10 V bias (Figure 21e) revealed a stable cycling performance under 350 nm (154 μW cm⁻²) and 700 nm (150 μW cm⁻²) light switching, with the photocurrent maintaining nearly identical magnitudes to its initial values after multiple cycles, particularly at 700 nm. Additionally, wavelength-dependent response/recovery times were observed: 0.29/0.59 s (350 nm) and 0.25/0.13 s (750 nm) (Figure 21f). The detector achieved superior figures of merit at 350 nm (detectivity: 3.24 × 10⁹ Jones; photomultiplication: 2.02) and 750 nm (1.09 × 10⁹ Jones; 16.0), confirming Au-NP-induced broadband performance enhancement.

The abundant p-n heterointerfaces in composite systems facilitate the efficient separation of photogenerated electron–hole pairs and enhanced carrier transport kinetics. Leveraging this principle, Wang et al. [206] developed Sb₂S₃ nanorod (NR)/CuSCN heterojunctions via sequential hydrothermal synthesis, constructing ITO/composite/ITO sandwich-structured devices for optoelectronic characterization. Under white-light illumination at zero bias, the photovoltaic effect-driven devices exhibited ultrafast response dynamics (rise/fall times: t_r/t_f = 0.18/0.15 s), confirming the superior self-powered photodetection capabilities of CuSCN/Sb₂S₃ heterostructures. In a parallel development, Jiang and Meng [207] synthesized Sb₂S₃ nanowire array (NWA)/Mo₂C-C composites hydrothermally, fabricating photodetectors with Au interdigitated electrodes. Compared to pristine Sb₂S₃ NW devices, the heterojunction system demonstrated accelerated response kinetics (t_r/t_f = 52.7/79.2 ms) and a 150-fold enhancement in current switching ratio (1.5 × 10²), underscoring the critical role of interfacial engineering in optoelectronic device optimization.

Bismuth Sulfide (Bi₂S₃)-Based Photodetectors

An ideal n-type semiconductor with excellent light absorption and a high absorption coefficient (~105 cm⁻¹) and photon conversion efficiency, Bi₂S₃ has a bandgap of 1.3–1.7 eV [208,209]. In particular, the low cost, non-toxicity, and good electrical conductivity of the material make Bi₂S₃ show great potential for applications in UV, visible, and NIR broad-spectrum photodetection [70,210,211].

Bi₂S₃ emerged as a pivotal photoactive material due to its narrow bandgap, high absorption coefficient, and efficient photon-to-carrier conversion capabilities [212]. Ding et al. [213] synthesized phase-pure Bi₂S₃ nanorods via a facile hydrothermal route, fabricating photodetectors through the dip-coating of nanorod films onto Al₂O₃ substrates with Au interdigitated electrodes. The devices exhibited pronounced photovoltaic behavior under illumination (Figure 22a), demonstrating a two-order-of-magnitude enhancement in photocurrent versus dark current across the applied biases. The cyclic current–time curve under a 5 V bias voltage (Figure 22b) demonstrated exceptional operational reproducibility and stability (98% photocurrent retention over 100 cycles) and rapid response dynamics (t_r/t_f = 371.66/386 ms). Complementing these findings, Yu et al. [214] developed colloidal Bi₂S₃ nanorods through sulfur-stoichiometry-controlled synthesis, constructing ITO/Bi₂S₃/ITO photodetectors. Current–voltage characteristics (Figure 22c) under visible illumination (475/550/650 nm, 4.1 mW cm⁻²) showed their wavelength-dependent photoconductivity, with maximal red-light responsivity (650 nm) indicating spectral selectivity. Dynamic testing at 1 V bias (Figure 22d) confirmed their robust photostability (<5% signal decay) and competitive response kinetics (t_r/t_f = 0.3/0.6 s), positioning Bi₂S₃ as a high-performance candidate for fast-switching optoelectronic systems.

Li’s group [215] synthesized single-crystalline Bi₂S₃ nanowires (NWs) via chemical vapor deposition (CVD), fabricating photodetectors through e-beam lithography and thermal evaporation techniques with Cr/Au electrode deposition at NW termini. Under 700 nm illumination (1 V bias, 1.54 mW cm⁻²), the devices exhibited rapid photoresponse activation (<0.1 s rise time) during cyclic on/off modulation. The detectors achieved a responsivity of 3.57 A/W and an external quantum efficiency (EQE) of 633%, demonstrating sub 100 ms temporal resolution and repeatable on/off cycling stability. To develop near-infrared (NIR)-polarized photodetectors with superior crystallinity, Wang et al. [216] synthesized high-crystallinity Bi₂S₃ nanowires (NWs) via chemical vapor deposition (CVD), fabricating devices by sputtering Pt electrodes on SiO₂-supported NWs. As illustrated in Figure 23a, the optimized NW photodetector demonstrates strong NIR photoresponsivity at 830 nm, outperforming previously reported nanorod-based analogs. Figure 23b displays the photoresponse of a single-Bi₂S₃-nanowire photodetector measured under laser illumination at wavelengths of 400 nm, 635 nm, and 830 nm (optical power density ≈ 250 mW/cm²). The device exhibits excellent signal stability and reproducibility across different wavelengths and power conditions, with rise/fall times of merely 12.25 ms. At an equivalent laser intensity (~250 mW/cm²), 830 nm illumination delivers higher photon flux compared to 400 nm and 635 nm light, generating more electron–hole pairs in the single Bi₂S₃ nanowire, consequently resulting in an enhanced photocurrent being observed under 830 nm irradiation. Power-dependent studies (Figure 23c,d) exhibit a trade-off between photocurrent amplification and responsivity degradation at elevated power densities (>52 mW cm⁻²), stemming from saturating carrier transport pathways under high photon flux. At 52 mW cm⁻² (830 nm, 1 V bias), the device achieves peak performance metrics: responsivity (4.21 A/W), detectivity (1.64 × 10¹⁰ Jones), and external quantum efficiency (981.76%). Polarization-resolved measurements demonstrate anisotropic photocurrent modulation, with the maximal response at 0°/180° alignment (parallel to NW axis) and the minimal response at 90°/270° (orthogonally polarized), yielding a dichroic ratio of 1.79. Similarly, Yi’s group [217] synthesized phase-pure Bi₂S₃ nanowires via atmospheric-pressure chemical vapor deposition (APCVD), employing a damage-free transfer method to assemble devices by positioning individual nanowires on SiO₂/Si substrates with lithographically patterned Ti/Au electrodes. The gate-modulated device (Vg = 30 V) demonstrated record optoelectronic metrics under 532 nm illumination (23.8 μW cm⁻²)—responsivity (2.376 × 10⁴ A/W), external quantum efficiency (5.55 × 10⁶%), and specific detectivity (3.68 × 10¹³ Jones)—surpassing those of previous architectures by orders of magnitude. Ultrafast response kinetics (t_r/t_f = 1/4.5 ms) and polarization-selective operation (dichroic ratio: 2.4 at 405 nm) were concurrently achieved, establishing Bi₂S₃ nanowires as a benchmark material for high-speed polarized photodetection in the visible spectrum.

To optimize photodetector performance through enhanced photogenerated carrier density, Xu et al. [218] fabricated Bi₂S₃ nanowire arrays (NWAs) on mica substrates via physical vapor deposition (PVD), engineering photodetectors with Au source/drain electrodes. The Bi₂S₃ NWA-based devices demonstrated exceptional photoresponsivity, achieving 5.23 × 10³ A W⁻¹ responsivity and 1.8 × 10¹² Jones detectivity under 830 nm illumination at ultralow intensity (64 nW cm⁻²). Notably, the architecture exhibited a photomultiplication factor of 7.8 × 10³, coupled with rapid response dynamics (rise/fall times: t_r/t_f = 21 μs/7.8 ms). Simultaneously, Maria et al. [219] engineered Bi₂S₃ homojunctions comprising nanorod arrays and gradient-thickness films (film thickness inversely proportional to deposition time) on carbon substrates via hot-plate-assisted physical vapor deposition (PVD), as schematized in Figure 24a. Electrical characterization was conducted using Ta microprobes to interface the Bi₂S₃ nanostructures with the carbon substrate. Under white-light illumination (22.7 W m⁻², 1 V bias), the homojunction exhibited a 4.5-fold photocurrent enhancement (4.5 μA vs. dark current 0.96 μA, Figure 24b), attributed to the parallel conduction pathways in nanorod arrays that minimized series resistance. The device demonstrates exceptional operational stability under high-power optical-switching conditions (Figure 24c), maintaining consistent dark/photocurrent levels with sub-second response dynamics (t_r/t_f = 192/270 ms). During prolonged switching cycle tests, the device exhibits minimal performance degradation, highlighting its superior repeatable stability. These results fully demonstrate the device’s capability to maintain a stable performance output under extreme operating conditions. The synergistic combination of high-surface-area nanorods and optically active thin films yielded superior optoelectronic metrics—responsivity (749.3 mA/W) and detectivity (5.61 × 10⁸ Jones)—validating the efficient interfacial charge harvesting in this hierarchical architecture. The integration of semiconductor nanostructures is an effective way to improve the performance of photodetection with the development of the technology. Here, Ghosh et al. [220], used an in situ hydrothermal method to anchor MXene (Ti₃C₂Tx) nanosheets in situ on one-dimensional Bi₂S₃ (BS) nanorods and utilized IDE-patterned gold (Au) electrodes to prepare a Bi₂S₃/Ti₃C₂Tx (TC) photodetector based on an Al substrate with excellent performance. To investigate the light absorption ability of their samples, the UV-Vis absorption spectra of different samples are shown in Figure 24d. The heterojunction material shows stronger absorption over the whole range (300–1800 nm) with a peak at about 770 nm compared to the pure BS nanorods and TC nanosheets. Comparing the photovoltaic performance of the devices, the PD made with the BS/TC material exhibits a high switching ratio (I_Light/I_Dark) of about 255, which is two orders of magnitude higher compared to the switching ratio of the pristine BS PD (~10), suggesting that the BSTC device has a higher photocurrent. The BSTC nanorod-based photodetector (PD) exhibits ultrafast response dynamics under 808 nm pulsed illumination (6.3 mW cm⁻²), achieving rise/fall times of t_r/t_f = 0.3/2.1 ms. Long-term stability tests (Figure 24e) reveal merely 0.6% photocurrent degradation after four months of ambient storage. The device demonstrates exceptional environmental stability and reproducible performance. Power-dependent characterization (Figure 24f) demonstrated its responsivity (R), external quantum efficiency (EQE), and detectivity (D*) degradation at elevated intensities, attributed to trap-state-mediated recombination in the BS nanorods. High photon flux exacerbates carrier trapping, accelerating electron–hole recombination and diminishing photocurrent yields. At ultralow power (0.03 mW cm⁻², 3 V bias), the device achieved peak responsivity (25.5 A/W), EQE (3.9 × 10³%), and detectivity (3.9 × 10¹² Jones), outperforming conventional BS-based architectures by two orders of magnitude.

Distinctly, Singh et al. [221] reported a Bi₂S₃/PANI hybrid photodetector by functionalizing hydrothermally synthesized Bi₂S₃ nanorods (NRs) with polyaniline (PANI) and integrating silver paste electrodes. This hybrid architecture enables interfacial charge transfer acceleration at Bi₂S₃-PANI junctions, yielding an ultralow dark current (0.003 μA) and enhanced photocurrent (0.58 μA) under 365 nm illumination (1 V bias, 50 μW cm⁻²). The device achieved the following benchmark optoelectronic metrics: responsivity (2.676 × 10⁴ A/W), detectivity (5.24 × 10¹³ Jones), external quantum efficiency (9073%), and rapid response kinetics (t_r/t_f = 50/63 ms). The synergistic interplay between Bi₂S₃’s narrow-bandgap absorption and PANI’s conductive framework suppresses dark carrier injection while facilitating photogenerated charge extraction, establishing a paradigm for organic–inorganic hybrid photodetector design. Remarkably, Devasia et al. [222] synthesized in situ-grown Cs₃Bi₂I₉:Bi₂S₃ nanorod (NR) composites on fluorine-doped tin oxide (FTO) substrates via single-step ultrasonic spray deposition (USD), fabricating photodiodes with spray-coated Ag-C electrodes. The Cs₃Bi₂I₉:Bi₂S₃ heterostructure exhibits intrinsic photosensitivity and operational photostability, achieving a photocurrent sensitivity of 198% (1.35 nA photocurrent vs. 0.68 nA dark current) at 1 V bias. In self-powered mode under 532 nm illumination (790 μW cm⁻²), the device demonstrated competitive photoresponsivity (0.59 mA W⁻¹) and specific detectivity (8.18 × 10⁹ Jones). The ultrabroadband spectral response (300–1550 nm) of this Bi₂S₃-based architecture positions it as a versatile candidate for next-generation broadband optoelectronic systems.

Titanium trisulfide (TiS₃), as a new material for a new generation of electronic and optical devices, exhibits an ultrabroadband optical absorption range with its small direct bandgap (1.1 eV). Currently, Randle et al. [223] and Liu’s group [224], based on quasi-one-dimensional titanium trisulfide (TiS₃) photovoltaic devices, have demonstrated that one-dimensional TiS₃ has unique and excellent photovoltaic properties, which provides a development direction for the fabrication of high-performance TiS₃-based photodetectors.

Comparative Analysis

Finally, we evaluate the photodetection capabilities of diverse one-dimensional (1D) metal trisulfide nanostructures. Among these, 1D Sb₂S₃, In₂S₃, and their composites have been extensively employed in high-sensitivity UV–visible photodetection. Notably, photodetectors (PDs) utilizing CVD-synthesized Sb₂S₃ NRs exhibit exceptional detection performance, achieving a specific detectivity of 2.1 × 10¹⁴ Jones. Similarly, single-crystalline In₂S₃ NW-based PDs fabricated via the same methodology demonstrate outstanding photoresponsivity (7.35 × 10⁴ A/W) and external quantum efficiency (EQE: 2.88 × 10⁷%). In contrast, Bi₂S₃-based photoconverters, while exhibiting weaker photoresponse magnitudes compared to Sb₂S₃ and In₂S₃, enable significantly accelerated optoelectronic signal transduction. For instance, Ti₃C₂Tₓ/Bi₂S₃ NR-based PDs achieve ultrafast photoresponses, with rise/decay times of 0.3/2.1 ms, respectively. These superior characteristics primarily originate from the narrow bandgaps inherent to metal trisulfides, which impart high carrier mobility and efficient charge separation/transport dynamics. Fundamentally, quantum confinement effects serve as dominant factors in the unique photoresponse behaviors of 1D nanostructures. A comparative summary of the 1D metal trisulfide-based PD performance is provided in

Table 6. Properties of one-dimensional polysulfide metal compound-based photodetectors and methods of material synthesis.

Material	Contact Electrodes	Methodology	Wavelength Power	Responsivity (A/W)	Detectivity (Jones)	EQE (%)	Rise Time Fall Time	Photo-I Dark-I	Ref.
In2S3 NWs	Cr/Au	NPT-CVT	405 nm 2 W/cm2	16.01	~	4903	~	9.95 nA 112.4 μA	[189]
In2S3 NWs	Au/Ni	CVD	450 nm 176.7 W/cm2	7.35 × 104	2.4 × 1014	2.88 × 107	6.5 ms 9.5 ms	0.29 pA 293 nA	[190]
Sb2S3 NWs	Au	Steam Transport	638 nm 0.03 mW/cm2	1152	2 × 1013	~	37 ms 38 ms	2 × 10−10 A 4.2 × 10−8 A	[198]
Sb2S3 NWs	Au	Steam Transport	450 nm 40 μW/cm2	343.4 m	~	~	470 μs 680 μs	69.6 times lower	[199]
Sb2S3 NWs	Ni/Au	CVD	532 nm 0.03 mW/cm2	65	2.1 × 1014	1.5 × 104	76 ms 83 ms	~ 2.5 nA	[200]
Sb2S3 NWs	Ti/Au	APCVD	635 nm 318 μW/cm2	270	4.37 × 1013	5.3 × 104	10 ms 12 ms	2800 times lower	[201]
Sb2S3 NRs	Au	Hydrothermal	560 nm 0.38 mW/cm2	5.1	2.16 × 1010	1130.68	4.03 ms 4.08 ms	109.8 times lower	[202]
Sb2S3 NTs		CVD	808 nm 300 mW/cm2	8.5 m	1.33 × 106	~	22 ms 24 ms	0.93 nA 185 nA	[203]
Sb2S3 NWA	FTO	Polyol Reflux	808 nm 640 mW/cm2	~	~	~	0.52 s 1.1 s	7.4 nA 113.5 nA	[204]
Au:Sb2S3 NWs	Cr/Au	CVD	600 nm 680 μW/cm2	59.5	4.29 × 1010	~	0.2 s 0.3 s	57 pA 163 nA	[205]
CuSCN/Sb2S3 NRs	ITO	Two-Step Hydrothermal	600 nm 680 μW/cm2	~	~	~	0.18 s 0.15 s	102 times lower	[206]
Mo2C-C/Sb2S3 NRs	Au	Hydrothermal	400 nm 320 W/cm2	~	~	~	52.7 ms 79.2 ms	150 times lower	[207]
Bi2S3 NRs	Au	One-Pot Hydrothermal	~	~	~	~	371.6 ms 386 ms	102 times lower	[213]
Bi2S3 NRs	ITO	Colloidal Chemical	650 nm 4.1 mW/cm2	~	~	~	0.3 s 0.6 s	10 times lower	[214]
Bi2S3 NWs	Cr/Au	CVD	700 nm 1.54 mW/cm2	3.57	~	633	0.1 0.1	~	[215]
Bi2S3 NWs	Pt	CVD	830 nm 52 mW/cm2	4.21	1.64 × 1010	981.76	12.25 ms 12.25 ms	~	[216]
Bi2S3 NWs	Ti/Au	APCVD	532 nm 23.8 μW/cm2	23,760	3.68 × 1013	5.5 × 106	1 ms 4.5 ms	~	[217]
Bi2S3 NRA	Au	PVD	830 nm 64 nW/cm2	5233	1.8 × 1012	7.8 × 103	21 μs 7.8 ms	~	[218]
Bi2S3 NRA	Ta	Hot Plate PVD	~ 22.7 W/cm2	749.6	5.61 × 108	~	192 ms 270 ms	0.96 μA 4.5 μA	[219]
Ti3C2Tx/Bi2S3 NRs	Au	In Situ Hydrothermal	808 nm 0.03 mW/cm2	2.55 × 10−2	3.9 × 1012	3.9 × 103	0.3 ms 2.1 ms	255 times lower	[220]
Bi2S3/PANI NRs	Ag	Hydrothermal	365 nm 50 μW/cm2	26,760	5.24 × 1013	9073	50 ms 60 ms	0.003 μA 0.58 μA	[221]
Cs3Bi2I9:Bi2S3 NRs	Ag/C	USD	532 nm 790 μW/cm2	0.59 × 10−3	8.18 × 109	198	~	0.68 nA 1.35 nA	[222]

. In collective comparison with standard photodetectors, this review underscores the exceptional responsivity (e.g., ZnS/CdS heterojunctions: >10⁴ A W⁻¹), detectivity (e.g., SnS₂ nanowires: ~10¹⁶ Jones), and spectral tunability of one-dimensional metal sulfide photodetectors. When benchmarked against conventional Si (R: 0.4–0.6 A W⁻¹; D: 10¹²–10¹³ Jones) and InGaAs (R: 0.8–1.2 A W⁻¹; D: 10¹¹–10¹² Jones) systems, these 1D metal sulfide architectures demonstrate orders-of-magnitude superiority in responsivity and detectivity metrics, coupled with broad spectral adaptability [24,25]. However, they encounter persistent challenges in their industrial-scale reproducibility and environmental resilience under extreme operational conditions. While metal sulfides excel in mechanical flexibility, visible-to-near-infrared (Vis-NIR) broadband operation, and low-power/self-powered functionality, they exhibit deficiencies in response uniformity and substrate integration maturity relative to their established counterparts. Future endeavors must bridge these gaps through compositional engineering and interface optimization, aiming to achieve commercial viability comparable to Si/InGaAs technologies in high-speed photonic applications such as imaging and telecommunications.

4. Challenges and Future Prospects

Although one-dimensional metal sulfide photodetectors demonstrate remarkable advantages in response speed, sensitivity, and spectral range, their practical applications still face multiple challenges. This section systematically analyzes the current technical bottlenecks and proposes critical research pathways for future investigations. Therefore, this section summarizes recent developments regarding self-powered and wide-spectrum thermally stable photodetectors for the reference of researchers.

4.1. Self-Powered Photodetector

Conventional photodetectors predominantly rely on external bias voltages, which constrain their applications in wearable and IoT scenarios. In contrast, self-powered devices require the simultaneous optimization of light absorption efficiency and built-in electric field strength [225]. This is exemplified by p-n junctions, which generate self-driven photovoltaic effects through interfacial band bending [226].

The research group led by Gao fabricated a Type-II CsPbBr₃/ZnS heterostructure photodetector with Al/ITO electrodes using hot-injection and spin-coating techniques (Figure 25a) [227]. Figure 25b presents the current–voltage (I-V) characteristics of the device under dark conditions and 365 nm illumination with varying intensities. The dark current curve exhibits a typical origin-passing behavior, while under illumination, the I-V curves show pronounced offsets at 0 V bias, with photocurrent enhancement proportional to light intensity, confirming the device’s photovoltaic conversion capability without external bias. This self-powered operation originates from the built-in potential-induced photovoltaic effect at the heterojunction interface. Figure 25c illustrates the photoresponse under varying optical intensities at 0 V bias, where rapid switching between illumination on/off states demonstrates efficient detection in self-powered mode. The device exhibits outstanding repeatable stability, enabling reliable operation across diverse power conditions. The measured rise (t_r) and fall (t_f) times are determined as 150 ms and 30 ms, respectively. Under 365 nm illumination (2 mW/cm²), the device achieves remarkable zero-bias performance: a photosensitivity of 1.38 × 10⁴, responsivity of 37.5 mA/W, and specific detectivity of 1.21 × 10¹² Jones.

Li et al. [228] fabricated a self-powered device (Figure 26a) through a combined chemical bath deposition (CBD) and spin-coating approach, where a uniform MAPbI₃/CdS thin film was deposited on an ITO substrate followed by Au electrode formation via vacuum thermal evaporation. Figure 26b displays the current–voltage (I-V) characteristics of the MAPbI₃/CdS photodetector under dark conditions and white-light illumination with varying power densities. A pronounced photocurrent emerges at zero bias, exhibiting linear enhancement with increasing optical power density, which substantiates the self-biased photovoltaic behavior. At 730 nm illumination (10 mW/cm²), the device achieves optimal performance, with a specific detectivity of 2.3 × 10¹¹ Jones (1 Jones = 1 cm·Hz¹/²·W⁻¹) and responsivity of 0.43 A/W. Figure 26c demonstrates the exceptional reproducibility and stability across multiple light on/off cycles in the tested devices. Specifically, the device exhibits highly consistent photoresponses under periodic illumination, confirming its reliability in prolonged operational scenarios. Compared to single-component devices, the heterojunction exhibits accelerated response characteristics, manifested by rise and decay times of 3.2 ms and 9.6 ms, respectively, attributed to efficient electron–hole separation and charge transfer at the heterointerface. Notably, Zhou’s group [229] recently developed a high-responsivity self-powered UV photodetector based on a ZnO nanoarray/CdS/GaN architecture employing ITO and In as top/bottom electrodes, expanding the research paradigm of heterostructure devices. Figure 26d presents the current–voltage (I-V) characteristics of the photodetector (PD) under dark conditions and 300 nm UV illumination (0.61 mW/cm²), with the inset showing Ohmic contact behavior at In/P-GaN interfaces. The dark current curve reveals a rectification ratio of 365 at 3 V bias, while pronounced photocurrent generation at zero bias under illumination confirms its self-powered operation. As shown in Figure 26e, periodic UV light switching tests under zero-bias conditions demonstrate repeatable photoresponse stability with minimal current fluctuation and rapid response characteristics (rise time t_r and fall time t_f < 0.35 s). Notably, under zero-bias operation (Figure 26f), the device achieves superior spectral responsivity (176 mA W⁻¹) and specific detectivity (10¹² Jones) compared to its CdS-free ZnO/GaN counterparts (27 mA W⁻¹), benefiting from an ultralow dark current (2 nA). This performance enhancement originates from the effective suppression of interfacial charge recombination and optimized electron transport pathways within the device architecture.

To develop photodetectors with concurrent high sensitivity, high responsivity, low power consumption, polarization sensitivity, and broadband detection capabilities, Xie et al. [230] fabricated vertically stacked Nb-WS₂/Ta₂NiSe₅ heterostructures via mechanical exfoliation and dry transfer techniques. Au electrodes were deposited by electron-beam evaporation to construct the low-power device shown in Figure 27a. The wavelength-dependent photocurrent measurements (Figure 27b) demonstrate rapid and stable optical responses across 405–1550 nm, confirming broadband operation. As illustrated in Figure 27c, under 600 nm illumination (0.035–275.67 mW/cm²), the source current at zero bias significantly exceeds the dark leakage current, verifying the device’s self-powered operation through photogenerated carrier separation driven by the built-in electric field. Under 660 nm laser illumination, the device has excellent response and recovery capabilities, with response and recovery times of 118 and 13 μs, respectively. At low light intensity (0.45 mW/cm²), remarkable figures of merit are achieved: an R of 57.64 A W⁻¹, D* of 6 × 10¹⁰ Jones, and EQE reaching 10,854%. In addition, Kumar’s group [231] successfully fabricated a self-powered broadband photodetector by spinning WS₂ nanoparticles on a MoS₂ substrate synthesized by chemical vapor deposition (CVD) and depositing Au/Cr cross-finger electrodes on the surface of thin films by shadow-assisted thermal evaporation technology. Figure 27d–f comparatively illustrate the photoelectronic characteristics of pristine MoS₂ and MoS₂-WS₂ heterojunctions under zero-bias (0 V) operation across visible to near-infrared (VIS-NIR) wavelengths (405–800 nm). Under 580 nm illumination (120 μW cm⁻²), the heterojunction device achieves a responsivity of 282.77 mA W⁻¹ and an EQE of 60.59%, representing 12-fold and 11-fold enhancements compared to MoS₂-based photodetectors (23.55 mA W⁻¹, 5.01%). Notably, the device exhibits improved response dynamics, with a 375 μs rise time and a 6 ms decay time, demonstrating significantly accelerated response speeds compared to pristine MoS₂ and WS₂ devices.

Its atomic-scale thickness and superior hetero-integration capability endow MoS₂ with significant potential for self-powered reconfigurable devices. Zhou et al. [232] demonstrated an Ar plasma-treated metal–semiconductor–metal (Ag-MoS₂-Pt) two-terminal structure, where reversible built-in electric field modulation via voltage-controlled sulfur vacancy concentration enabled a bidirectional self-powered photocurrent. Under 532 nm illumination (0.519 mW/mm²), the device achieved record response speeds of 224 μs (rise)/293 μs (decay) and a peak responsivity of 280 mA W⁻¹ at zero bias, with a self-biased detectivity of 0.76 × 10¹¹ Jones and an EQE of 65%. While emerging active materials advance photodetector technology, the trade-off between spectral sensitivity and operational efficiency persists. Vashishtha’s group [158] engineered a MoS₂/GaN epitaxial heterostructure-based self-powered detector (Au/Ni electrodes) featuring dual-band UV-Vis detection in a two-terminal configuration (Figure 28a). Its absorption spectra (Figure 28b) reveal enhanced UV absorption and a broadened visible response compared to bare GaN. As depicted in Figure 28c,d, the device maintains consistent switching dynamics under UV–visible illumination, exhibiting minimal current degradation and retaining alignment with initial current values across multiple periodic illumination cycles at varying power levels, demonstrating exceptional repeatable stability in extreme operational environments. With rise/decay times of 1.04/0.8 ms and 0.9/0.8 ms, respectively, the device achieves dual-mode operation featuring responsivities of 631/37 mA W⁻¹, detectivities of 8.5 × 10¹⁰/0.5 × 10¹⁰ Jones, and EQE values of 214%/8%, providing an innovative solution for cutting-edge applications.

The development of self-powered three-dimensional photodetectors (3DPDs) based on heterostructures faces significant challenges due to technical bottlenecks in the three-dimensional assembly of heterojunctions and the precise control of electrode interface matching. To address this issue, Shen’s research group [233] pioneered a novel approach by employing molecular beam epitaxy (MBE) technology combined with a controlled rolling assembly strategy for tubular MoS₂/GaAs/InGaAs heterostructures and the meticulous fabrication of Ni/Au composite electrodes, successfully demonstrating the first polarization-sensitive self-powered 3D photodetector (Figure 29a). To investigate the light intensity dependence of device performance under self-bias conditions, Figure 29b presents the current–voltage characteristics under 650 nm illumination. Experimental results reveal a monotonic increase in photocurrent with light intensity, ranging from dark-state to 970 mW/cm², while maintaining a dark current (I_dark) of 2 × 10⁻¹¹ A and achieving a maximum on/off ratio of 2.0 × 10³, indicating superior photoresponse tolerance. Further analysis through responsivity (R) and external quantum efficiency (EQE) versus light intensity curves (Figure 29c) demonstrates the exponential growth characteristics of both R and EQE under zero bias as light intensity decreases, reaching 86 mA W⁻¹ and 16%, respectively, at the minimum light intensity of 3.48 mW cm⁻². Furthermore, the environmentally benign layered semiconductor SnS₂ has attracted considerable attention due to its tunable bandgap and potential in high-performance photodetection. Deng’s team [234] successfully fabricated SnS₂ nano-wall arrays on FTO substrates via a facile hydrothermal method, implementing them as photoanodes in self-powered photodetectors. Remarkably, the devices exhibit outstanding photocurrent density (39.06 μA cm⁻²), responsivity (1460 μA/W), and cycling stability under 475 nm illumination (10.8 mW cm⁻²), providing new insights for expanding the applications of two-dimensional materials in optoelectronic detection.

Antimony trisulfide (Sb₂S₃) photodetectors (PDs) demonstrate promising application potential. Efficient carrier transport in PDs critically governs their detectivity and response speed. Kang’s group [235] synthesized a fully inorganic self-powered Sb₂S₃/TiO₂ PD with FTO/Au electrodes (Figure 30a) via the hydrothermal growth of vertically aligned TiO₂ nanorod arrays followed by the spin-coating of Sb₂S₃. The one-dimensional TiO₂ nanorod architecture facilitated the effective separation and transport of photogenerated carriers, thereby significantly enhancing device performance. Figure 30b displays the current–time (I-t) curve of the device under zero bias at an illumination power density of 400 W cm⁻². The PD exhibits stable photoresponses across wavelengths within the visible spectrum (380–760 nm), with a maximum photocurrent of 4.5 μA observed under red light (625 nm). Figure 30c presents the current–voltage (I-V) characteristics of the Sb₂S₃ PD under dark conditions and varying optical power densities at 625 nm. The photocurrent increases progressively with incident power density, highlighting the device’s superior self-powered functionality. At 625 nm illumination (9 W cm⁻²), the device achieves a responsivity (R) of 0.29 A W⁻¹ and specific detectivity (D*) of 3.37 × 10¹² Jones. The temporal response of the c-TiO₂/TiO₂-NRs/Sb₂S₃ PD under 625 nm illumination (Figure 30d) reveals rapid rise and decay times of 9.3 μs and 7.8 μs, respectively, indicating substantial commercial viability. For comparison, Zamani et al. [236] fabricated a p-Si/Bi₂S₃ heterojunction via chemical vapor deposition (CVD) and explored the role of Au coating in optoelectronic applications. The sample with Au deposited at 420 °C exhibited the highest carrier concentration (7.67 × 10¹⁸ cm⁻³). The p-Si/n-Bi₂S₃ heterojunction PD demonstrated remarkable self-biased detection performance in the red wavelength regime, achieving a responsivity of 0.94 mA W⁻¹ and detectivity of 6.40 × 10⁸ Jones.

Recent advances in self-powered photodetectors (PDs) highlight the critical role of heterojunction engineering and interface optimization in achieving high responsivity, rapid responses, and broadband detection without external bias, as summarized in

Table 7. Performance comparison of self-powered photodetectors.

Material	Contact Electrodes	Methodology	Wavelength Power	Responsivity (A/W)	Detectivity (Jones)	EQE (%)	Rise Time Fall Time	Ref.
CsPbBr3/ZnS	Al/ITO	Hot injection and spin coating	365 nm 2 mW/cm2	37.5 m	1.21 × 1012	~	150 ms 30 ms	[227]
MAPbI3/CdS	Au/ITO	CBD	325 nm 10 mW/cm2	0.43	2.3 × 1011	~	3.2 ms 9.6 ms	[228]
ZnO/CdS/GaN	In/ITO	~	300 nm 0.61 mW/cm2	176 m	1012	719	<0.35 s <0.35 s	[229]
Nb-WS2/Ta2NiSe5	Au	Mechanical exfoliation and dry transfer techniques	660 nm 0.45 mW/cm2	57.64	6 × 1010	10,854	118 μs 13 μs	[230]
MoS2/WS2	Au/Cr	Spin coating and CVD	580 nm 120 μW/cm2	282 m	~	60.59	375 μs 6 ms	[231]
Ag-MoS2	Pt	Ar plasma	532 nm 0.519 W/cm2	280 m	0.76 × 1011	65	224 μs 293 μs	[232]
MoS2/GaN	Au/Ni	Vapor transfer	UV 0.93 mW/cm2	631 m	8.5 × 1010	214	1.04 ms 0.8 ms	[158]
MoS2/GaAs/InGaAs	Au/Ni	MBE	650 nm 3.48 mW/cm2	86 m	2.3 × 1016	16	12.6 ms 18 ms	[233]
SnS2	FTO	Hydrothermal	475 nm 10 mW/cm2	1460 μ	~	~	~	[234]
TiO2/Sb2S3	FTO/Au	Hydrothermal and spin coating	625 nm 9 W/cm2	0.29	3.37 × 1012	·~	9.3µs 7.8µs	[235]
p-Si/Bi2S3	Au	CVD	Red ~	0.94 m	8.92 × 108	29,685	~	[236]

, in recent performance studies. However, challenges remain in these devices’ scalable fabrication, spectral selectivity, and long-term stability.

4.2. Thermal Stability and Broadband Testing

Under high-temperature conditions, sulfide materials are prone to sulfur volatilization (e.g., sulfur loss in Bi₂S₃ at temperatures > 200 °C) and lattice distortion, leading to device performance degradation. Furthermore, broadband detection (spanning ultraviolet to near-infrared wavelengths) imposes stringent requirements on material properties, typically necessitating gradient bandgap designs or heterojunction architectures to achieve wide-spectrum responsivity. However, interfacial defects can significantly enhance carrier recombination, severely limiting the photoelectric conversion efficiency of devices. Thus, the development of thermally stable broadband detection materials, coupled with interface engineering strategies to address temperature fluctuations and harsh environmental conditions, has become an urgent research priority.

Yadav et al. [237] synthesized hexagonal-phase SnS₂ nanosheets via a facile and low-cost solvothermal method. A SnS₂ nanosheet-based ultraviolet photodetector (PD) was fabricated using silver (Ag) as contact electrodes, with the device architecture illustrated in Figure 31a. The device exhibited remarkable thermal stability and high-precision UV detection capability: under a 5 V bias, the dark current increased merely 1.2-fold as the temperature rose from 60 °C to 120 °C (Figure 31b). Photoelectronic characterization at a 365 nm wavelength with 5 V bias revealed the device’s superior sensitivity (~400), responsivity (~5.5 A W⁻¹), external quantum efficiency (EQE, ~1868%), and detectivity (~1.72 × 10¹³ Jones). Temporal response measurements under UV illumination (1.112 mW cm⁻²) with a 20 s light switching cycle (Figure 31c) showed rise and fall times of 2.2 s and 6.3 s, respectively (inset of Figure 31c). The device’s current stability in harsh environments demonstrates its reproducible resilient operation across varying temperatures, likely originating from the enhanced carrier vibration and migration induced by elevated thermal conditions. The prolonged rise time was attributed to the wide inter-electrode spacing between Ag contacts, which extended the transit time of photogenerated carriers. Similarly, Jin et al. [238] fabricated a conjugated polymer PThTPTI/WS₂ heterojunction film via chemical vapor deposition (CVD) and constructed Au-electrode devices using shadow mask thermal evaporation (Figure 31d). The resulting PD demonstrated stable operation in ambient air at temperatures up to 300 °C. For the non-annealed PThTPTI/WS₂ PD, both rise and decay times increased significantly with temperature (Figure 31e: from 17 ms to 6.89 s for rise time and 38 ms to 8.43 s for decay time between 25 °C and 300 °C). This behavior originated from enhanced electron accumulation at the PThTPTI/WS₂ interface under elevated temperatures, prolonging the carrier redistribution equilibrium time (thus increasing rise time). During light-off phases, the trapped electrons in WS₂ nanosheets required extended diffusion periods to return to the interface at higher temperatures, leading to longer decay times. Notably, post-annealing treatment preserved the device performance (Figure 31f), confirming exceptional thermal stability in ambient air at 300 °C.

Furthermore, Vashishtha et al. [239] deposited MoS₂ thin films on Si₃N₄ substrates via radio-frequency (RF) sputtering and fabricated Pt electrode contacts on the MoS₂ surface through DC sputtering, resulting in the optoelectronic device shown in Figure 32a. High-temperature stability evaluation at 100 °C revealed a dark current of 2.5 µA in current–voltage (I-V) measurements (Figure 32b), slightly higher than the room-temperature value (1 µA). This increase in dark current originated from thermionic emission (Edison effect). Since the charge carrier mobility (μ) is positively correlated with temperature (μ α KBT), the current increases with increasing temperature. The transient photoresponse under 950 nm illumination (2 µW) at 100 °C (Figure 32c) demonstrated stable operation over multiple light switching cycles, with a photocurrent (2.3 µA) comparable to the room-temperature value (2.7 µA). The device also exhibited superior optoelectronic parameters at 100 °C, including responsivity (1170 mA W⁻¹), external quantum efficiency (409%), and specific detectivity (1.6 × 10¹⁰ Jones). Similarly, the MoS₂/GaN detector developed by Vashishtha’s group [158] achieved high-efficiency detection under zero bias and maintained stable operation at 100 °C, highlighting the potential of self-powered thermally robust devices for cutting-edge applications. The inherent flexibility and unique fluidity of organic materials not only suit wearable technologies but also enhance thermal dissipation. Leveraging this, Wahalathantrige’s group [240] synthesized a vinyl-functionalized diketopyrrolopyrrole polymer (PDPPVTT)/MoS₂ hybrid via chemical vapor transport (CVT) and solution processing, followed by Au/Cr electrode fabrication. Owing to the polymer’s high absorption coefficient (or molar absorptivity) in the 800 nm region, the device delivered a high photocurrent of 325 nA under 0.9 nW illumination (20 V), with its responsivity (R) reaching 10³ A W⁻¹. To further enhance MoS₂-based photodetector performance, Li et al. [241] introduced an Al₂O₃ atomic-layer stress buffer into MoS₂/GaN films through CVD and atomic layer deposition (ALD), constructing a device with Au/Cr electrodes. The Al₂O₃-induced tensile strain softened phonon vibrations and reduced thermal conductivity in MoS₂, endowing the device with exceptional thermal stability. Under 365 nm illumination (3.141 μW), it achieved a responsivity of 24.62 A W⁻¹, accompanied by a photoconductive gain of 520 and EQE of 8381%.

Gallium oxide (Ga₂O₃), characterized by its polymorphic nature and exceptional thermal stability, demonstrates significant potential for high-temperature optoelectronic applications [242]. The Xiong research group [243] epitaxially grew Ga₂O₃ thin films on aluminum nitride substrates via chemical vapor deposition (CVD), subsequently fabricating Au/Ni interdigital electrodes through photolithography and magnetron sputtering to construct a Ga₂O₃-based ultraviolet photodetector (Figure 33a). Under 274 µW cm⁻² illumination at 250 nm, Figure 33b presents the comparative current–voltage (I-V) characteristics under dark and illuminated conditions. At an operational temperature of 200 °C, the device achieved a photocurrent-to-dark-current ratio exceeding 10². The temporal photoresponse characteristics shown in Figure 33c demonstrate consistent response times across the 50–200 °C temperature range under 250 nm illumination, confirming excellent thermal stability. Compared to the room-temperature (25 °C) responsivity (3.2 × 10^–4 A W⁻¹) of IZO/β-Ga₂O₃/IZO photodetectors, this device exhibited a significantly enhanced responsivity of 0.518 A W⁻¹ at 200 °C. Zhang et al. [244] developed a self-powered deep-ultraviolet photodetector with an all-oxide configuration (Figure 33d) by constructing ε-Ga₂O₃/ZnO heterojunctions through CVD and depositing Ti/Au electrodes via magnetron sputtering. Figure 33e illustrates the device’s robust rectification characteristics under 254 nm illumination (400 µW cm⁻²) across various temperatures. At room temperature, photocurrents of 0.3 µA and 5.5 nA were obtained under −5 V and 0 V biases, respectively, indicating efficient photoconversion. Remarkably, the device maintained a high photocurrent-to-dark-current ratio of 10² even at extreme temperatures exceeding 500 K. Figure 33f reveals the temperature dependence of response times, where the rise/decay times showed negligible correlation with temperature despite amplitude variations in current spikes, suggesting temperature-independent carrier generation–recombination dynamics. The room-temperature self-powered operation yielded a responsivity of 2.4 mA W⁻¹, detectivity of 5 Jones, and external quantum efficiency of 1.5%, providing critical insights for developing thermally stable chalcogenide-based photodetectors.

In recent years, photodetectors have made remarkable progress in the fields of thermal stability and wide-spectrum detection, as shown in

Table 8. Performance comparison of high-temperature photodetector devices.

Material	Contact Electrodes	Methodology	Operating Temperature (℃)	Responsivity (A/W)	Detectivity (Jones)	EQE (%)	Rise Time Fall Time	Ref.
SnS2	Ag	Solvothermal method	120	5.5	1.72 × 1013	1868	2.2 s 6.3 s	[237]
PThTPTI/WS2	Au	CVD	300	~	~	~	6.89 ms 8.43 ms	[238]
MoS2	Pt	RF sputtering technology	100	1170 m	1.6 × 1010	409	~	[239]
MoS2/GaN	Au	Vapor transfer	100	631 m	8.5 × 1010	214	1.04 ms 0.8 ms	[158]
PDPPVTT/MoS2	Au/Cr	CVT	~	~	~	~	~	[240]
MoS2/GaN/Al2O3	Au/Cr	CVD and ALD	~	24.62	~	8381	~	[241]
Ga2O3	Au/Ni	CVD	200	0.518	~	~	~	[243]
ε-Ga2 O3/ZnO	Ti/Au	CVD	>500 K	2.4 m	5	1.5	~	[244]

. The devices still exhibit good detection performance at high temperatures. However, the volatilization of sulfur at high temperatures and interface defects in sulfides remain bottlenecks to efficiency. It is necessary to further optimize the gradient bandgap design, stress regulation (such as an Al₂O₃ buffer layer) and the integration process of sulfides/oxides (Ga₂O₃) to expand the application in extreme environments.

4.3. Active Region

The active region constitutes the critical domain in photodetectors where photogenerated electron–hole pairs undergo generation and recombination processes. Its fundamental operational mechanism involves efficient photon absorption and subsequent carrier generation, followed by directional charge collection to establish a measurable photocurrent. The photoelectric conversion efficiency is critically determined by strategic material selection and the optimized architectural design of this functional zone [245]. Notably, the thickness of the active region significantly impacts light absorption efficiency. Studies show that an active region thickness of 100 nm concentrates the optical field distribution within the absorption layer, thereby enhancing photodetector performance. However, increasing the thickness to 150 nm introduces multiple minima in the optical field distribution, thereby reducing the average optical energy density and degrading photoelectric conversion efficiency [246,247]. Additionally, reducing barrier thickness (e.g., from 10 nm to 5 nm) significantly mitigates gain inhomogeneity in p-side quantum wells, improving device performance [248]. Thus, optimizing the active region thickness is critical for advancing photodetector capabilities. Future research should focus on developing low-cost, scalable fabrication techniques, such as solution-based methods and chemical vapor deposition (CVD), while expanding the active region through structural and material optimization in order to enhance the overall performance of photodetectors.

4.4. Current Limitations and Future Directions

While one-dimensional metal sulfide photodetectors exhibit remarkable advantages in response speed, sensitivity, and spectral range, their practical implementation encounters multiple challenges. This section systematically analyzes existing technical bottlenecks and proposes critical research directions for future investigations. The discussion specifically addresses fundamental challenges—environmental stability, scalability, and the toxicity of cadmium-based materials—all of which are critical for the commercial viability of photodetectors.

4.4.1. Environmental Stability

The environmental stability of metal sulfide nanomaterials constitutes a critical limitation for their practical deployment. Materials such as CdS and SnS₂ are prone to surface sulfide hydrolysis or oxidation in high-humidity or oxidative environments (e.g., CdS + H₂O → Cd(OH)₂ + H₂S ↑), resulting in photoresponsive performance degradation [234]. Furthermore, two-dimensional derivatives like MoS₂ and WS₂ undergo accelerated degradation under prolonged illumination due to photocatalytic effects [249]. Mitigation strategies against this include surface passivation (e.g., Al₂O₃ encapsulation via atomic layer deposition) and heterojunction engineering (e.g., ZnS/CdS core–shell architectures), which effectively suppress environmental degradation [250]. For instance, Zhang et al. demonstrated that SiO₂-coated CdS nanowires extended device operational lifetime from 72 h to 1000 h under 85% relative humidity [251].

4.4.2. Scalability

The current synthesis methods for 1D metal sulfides (e.g., chemical vapor deposition, hydrothermal synthesis) predominantly rely on precision-controlled conditions (e.g., high temperatures, vacuum), posing challenges for cost-effective large-scale production. For example, CdS nanowires exhibit vapor-phase growth rates limited to micrometers per hour, with substrate sizes typically constrained to <10 cm² [252]. Emerging techniques such as template-assisted electrochemical deposition or inkjet printing enable high-throughput fabrication but compromise crystallographic quality and device performance (e.g., 30–50% mobility reduction) [253]. Future efforts should explore compromise strategies balancing scalability and performance, such as self-assembled monolayer modulation or continuous-flow reactor designs.

4.4.3. Toxicity of Cadmium-Based Materials

Cadmium-based compounds like CdS and CdSe face stringent environmental regulations (e.g., EU RoHS Directive) due to their high toxicity (carcinogenicity, bioaccumulation). Despite their superior photoresponsive performance (e.g., CdS nanowire detectivity up to 10¹⁶ Jones), industrial adoption necessitates risk–performance trade-offs. Significant progress has been made in alternative materials: SnS₂ (low toxicity, tunable bandgap to 2.1 eV) and Sb₂S₃ (heavy-metal-free) achieve detectivities approaching 10¹⁶ Jones [254], though their response speeds (ms) lag behind CdS (μs) [139,172]. Furthermore, inadequate recycling technologies exacerbate environmental burdens; currently, only 30% of cadmium is recoverable via hydrometallurgical processes [220], urgently demanding closed-loop manufacturing processes.

4.4.4. Future Research Directions

To address future societal development demands, interdisciplinary efforts should prioritize the following aspects: (1) Developing low-temperature synthesis methods (e.g., inkjet printing, roll-to-roll processing) for depositing one-dimensional sulfides on stretchable substrates (e.g., PET, PDMS) to fabricate flexible and wearable integrated products. Recent advances in Ag nanowires/ZnS nanotubes have demonstrated exceptional mechanical durability, maintaining 95% of their initial response after 1000 bending cycles [255]. (2) Employing artificial intelligence to predict optimal material compositions (e.g., doping ratios, heterojunction pairings) and device architectures. Neural networks have successfully reduced experimental optimization cycles by 70% for MoS₂-based detectors, while simultaneously maximizing EQE [256]. (3) Integrating one-dimensional sulfides with two-dimensional materials (e.g., graphene, MXenes) or perovskites to achieve synergistic effects. A recently developed Bi₂S₃/MXene composite has achieved broadband detection (300–1800 nm) with an ultrafast response (0.3 ms) [257], highlighting the potential of this strategy.

5. Conclusions and Outlook

This review comprehensively examines recent advances in the photodetection properties of one-dimensional (1D) metal sulfide nanostructures and their corresponding devices. We first outline the operational mechanisms of photodetectors, their critical performance parameters, and their dominant device architectures. Subsequently, we systematically analyze device structures, synthesis methodologies, and performance metrics through comparative evaluation. Notably, photodetector performance demonstrates heightened sensitivity to carrier mobility, surface-to-volume ratios, and interfacial contact resistance between photosensitive layers and electrodes. Furthermore, morphological modifications, electrode selections, and synthetic approaches introduce substantial performance variations across devices. Nevertheless, 1D metal sulfide-based photodetectors demonstrate superior specific surface areas and abundant surface oxygen desorption sites compared to their thin-film and metal oxide counterparts, thereby enabling enhanced optoelectronic functionalities.

One-dimensional (1D) single-chalcogenide metal compound nanostructures have garnered significant research attention due to their structural tunability and optoelectronic performance. For instance, chemical vapor deposition (CVD)-synthesized CdS nanowire (NW)-based photodetectors (PDs) demonstrate exceptional responsivity (2.6 × 10⁵ A/W) and specific detectivity (2.3 × 10¹⁶ Jones) upon ferroelectric polymer polarization, attributed to the drastic suppression of dark current via intrinsic carrier depletion and photon-generated current dominance. Transition metal disulfides (WS₂, SnS₂, MoS₂, ReS₂) in 1D configurations exhibit broad spectral absorption, high porosity, and optimal bandgaps, enabling high carrier mobility and rapid response speeds for ultrasensitive photodetection. Notably, emerging ReS₂ NW-PDs achieve record responsivity (5.08 × 10⁵ A/W), detectivity (6.1 × 10¹⁵ Jones), and EQE (1.07 × 10⁶%), facilitated by ultralow ReS₂/Ag interfacial contact resistance that enhances charge extraction efficiency. Enhanced sulfur stoichiometry promotes crystallinity, passivating surface defects and substantially improving device performance. Among 1D trisulfides (Sb₂S₃, Bi₂S₃, In₂S₃), high-crystallinity Sb₂S₃ NWs exhibit superior detectivity (2.1 × 10¹⁴ Jones), EQE (1.5 × 10⁴%), and sensitivity (2.2 × 10⁴), primarily due to their minimized impurity incorporation (e.g., organometallic precursors, surfactants) via crystallinity-driven surface stabilization. These advances underscore the potential of 1D metal sulfides in next-generation photodetectors. By synthesizing the recent progress in self-powered and thermally stable PDs, this review establishes critical benchmarks for future research. Prioritizing material/structural optimization, multifunctional integration, and environmental resilience will drive advancements in low-power, high-stability photodetection technologies.

Despite notable breakthroughs in the synthesis and design of one-dimensional (1D) metal sulfide-based photodetectors, substantial advancements in both synthesis methodologies and performance metrics—relative to 1D metal oxides and 2D metal sulfides—remain essential in order to address emerging demands across diverse applications. To further advance 1D metal sulfide photodetectors, priority should be given to the following considerations:

(1)

When utilizing doped elements or constructing heterostructures to improve the sensitivity and responsivity of photodetectors, there remains a need to develop new, effective methods for achieving efficient detection, for example, via the polarization effect of ferroelectric polymers on the device; however, the specific effect of ferroelectric polarization on the optical response and the underlying principles need to be further studied.

(2)

The exploration of homogeneous hybridized nanostructures as photodetectors and the in-depth investigation of the principles at work are essential, as the complex interfaces and carrier migration pathways in hybridized nanostructures often give rise to unique optical and photoelectronic properties.

(3)

Due to the flexibility, transparency, and low cost of organic materials, the study of nanostructured material photodetectors with different polymer modifications can lead to the development of more stable and flexible devices while reducing costs.

(4)

Devices with high thermal stability and self-powering capabilities not only contribute significantly to energy conservation and emissions reduction but also offer critical utility in harsh environmental exploration. Consequently, the development of high-performance thermally stable materials and the realization of efficient devices under zero-bias conditions remain pressing challenges that demand accelerated exploration by researchers.

(5)

Finally, although numerous methodologies exist for material synthesis and device fabrication, synthesis processes remain challenging to control effectively. Furthermore, device manufacturing typically involves integrated processes combining photolithography, etching, and deposition. Undoubtedly, such inherently complex and time-consuming procedures hinder economic viability. Consequently, advancing fabrication techniques to streamline these processes remains a critical area for exploration.