Search Results (57)

Inorganic halide perovskites have garnered significant attention as promising candidates for photovoltaic and optoelectronic applications, owing to their enhanced thermal and chemical stability relative to hybrid perovskite materials. This review synthesizes recent progress in vapor-phase deposition methodologies, such as co-evaporation, close space sublimation (CSS), continuous flash sublimation (CFS), and chemical vapor deposition (CVD), which enable the precise modulation of film composition and morphology. Advances in material systems, including the stabilization of CsPbI₂Br, the introduction of tin-doped phases, and the investigation of lead-free double perovskites like Cs₂AgSbI₆ and Cs₂AgBiCl₆, are critically evaluated with respect to their impact on device performance. The incorporation of these materials into photovoltaic devices and tandem configurations is explored, with particular emphasis on improvements in power conversion efficiency and operational durability. Furthermore, interface engineering approaches tailored to vacuum-deposited films—such as defect passivation and energy-level alignment—are examined in detail. The potential for scalable manufacturing is assessed through simulation analyses, throughput modeling, and pilot-scale demonstrations, underscoring the feasibility of industrial-scale production. By offering a comprehensive overview of these advancements, this review provides valuable perspectives on the current landscape and prospective trajectories of vapor-deposited inorganic perovskite technologies. Full article

Single-phase white-light-emitting materials, particularly 2D hybrid organic–inorganic halide perovskites, have garnered significant attention due to their strong electron–phonon interactions, which lead to broad luminescence and a notable Stokes shift resulting from self-trapped exciton recombination. However, 2D lead iodide perovskites typically display these characteristics poorly, restricting their efficiency as white-light emitters. This study presents a 2D lead iodide perovskite that incorporates a fluorinated π-conjugated aggregation-induced enhanced emission luminophore, FPCSA, as a bulky organic cation to create a quasi-2D perovskite. The FPCSA cation establishes a Type II energy level alignment with the lead iodide layer in the 2D perovskite, and a significant energy offset effectively suppresses charge transfer, enabling independent emission from both the organic and inorganic layers while facilitating self-trapped exciton formation. Under 315 nm UV excitation, this material demonstrates warm white-light emission with RGB triple-band photoluminescence stemming from the electronically decoupled FPCSA and perovskite layers. These findings provide a promising new method for designing efficient single-phase white-light-emitting materials for optoelectronic applications. Full article

Semiconductor photonic nanowires are critical components for nanoscale light manipulation in integrated photonic and electronic devices. Optimizing their optical performance requires enhanced photon conversion efficiency, for which a promising solution is to combine semiconductors with noble metals, using the surface plasmon resonance of noble metals to enhance the photon absorption efficiency. Here, we report plasmon-enhanced light emission in a hybrid nanowire device composed of perovskite semiconductor nanowires and silver nanoparticles formed using superfluid helium droplets. A cesium lead halide perovskite-based four-layer structure (CsPbBr₃/PMMA/Ag/Si) effectively reduces the metal’s plasmonic losses while ensuring efficient surface plasmon–photon coupling at moderate power. Microphotoluminescence and time-resolved spectroscopy techniques are used to investigate the optical properties and emission dynamics of carriers and excitons within the hybrid device. Our results demonstrate an intensity enhancement factor of 29 compared with pure semiconductor structures at 4 K, along with enhanced carrier recombination dynamics due to plasmonic interactions between silver nanoparticles and perovskite nanowires. This work advances existing approaches for exciting photonic nanowires at low photon densities, with potential applications in optimizing single-photon excitations and emissions for quantum information processing. Full article

The most commonly used optical oxygen sensing materials are phosphorescent molecules and functionalized nanocrystals. Many exploration studies on oxygen sensing have been carried out using the fluorescence or phosphorescence of semiconductor nanomaterials. Lead halide perovskite nanocrystals, a new type of ionic semiconductor, have excellent optical properties, making them suitable for use in optoelectronic devices. They also show promising applications in analytical sensing and biological imaging, especially manganese-doped perovskite nanocrystals for optical oxygen sensing. As a class of materials with diverse sources, copper iodide cluster semiconductors have rich structural and excellent luminescent properties, and have attracted attention in recent years. These materials have adjustable optical properties and sensitive stimulus response properties, showing great potential for optical sensing applications. This review paper provides a brief introduction to traditional oxygen sensing using organic molecules and introduces research on oxygen sensing using novel luminescent semiconductor materials, perovskite metal halides and copper iodide hybrid materials in recent years. It focuses on the mechanism and application of these materials for oxygen sensing and evaluates the future development direction of these materials for oxygen sensing. Full article

Halide perovskite materials have garnered significant research attention due to their remarkable performance in both photoharvesting photovoltaics and photoemission applications. Recently, self-assembled CsPbBr₃ superstructures (SSs) have been demonstrated to be promising lasing materials. In this study, we report the ultrastable two-photon-pumped amplified stimulated emission from a CsPbBr₃ SS/Ag hybrid microcavity with a low threshold of 0.8 mJ/cm² at room temperature. The experimental results combined with numerical simulations show that the CsPbBr₃ SS exhibits a significant enhancement in the electromagnetic properties in the hybrid microcavity on Ag film, leading to the uniform spatial temperature distribution under the irradiation of a pulsed laser, which is conducive to facilitate the recrystallization process of the QDs and improve their structural integrity and optical properties. This study provides a new idea for the application of CsPbBr₃/Ag hybrid microcavity in photonic devices, demonstrating its potential in efficient optical amplification and upconversion lasers. Full article

Hybrid organic-inorganic lead halide perovskites (LHPs) have emerged as a highly significant class of materials due to their tunable and adaptable properties, which make them suitable for a wide range of applications. One of the strategies for tuning and optimizing LHP-based devices is the substitution of cations and/or anions in LHPs. The impact of Cs substitution at the A site on the structural, vibrational, and elastic properties of MA_xCs_1−xPbCl₃-mixed single crystals was investigated using X-ray diffraction (XRD) and Raman and Brillouin light scattering techniques. The XRD results confirmed the successful synthesis of impurity-free single crystals, which exhibited a phase coexistence of dominant cubic and minor orthorhombic symmetries. Raman spectroscopy was used to analyze the vibrational modes associated with the PbCl₆ octahedra and the A-site cation movements, thereby revealing the influence of cesium incorporation on the lattice dynamics. Brillouin spectroscopy was employed to investigate the changes in elastic properties resulting from the Cs substitution. The incorporation of Cs cations induced lattice distortions within the inorganic framework, disrupting the hydrogen bonding between the MA cations and PbCl₆ octahedra, which in turn affected the elastic constants and the sound velocities. The substitution of the MA cations with smaller Cs cations resulted in a stiffer lattice structure, with the two elastic constants increasing up to a Cs content of 30%. The current findings facilitate a fundamental understanding of mixed lead chloride perovskite materials, providing valuable insights into their structural and vibrational properties. Full article

Hybrid lead iodide perovskites are promising photovoltaic and light-emitting materials. Extant literature data on the key optoelectronic and luminescent properties of hybrid perovskites indicate that these properties are affected by electron–phonon coupling, the dynamics of the organic cations, and the degree of lattice distortion. We report temperature-dependent Raman studies of BA₂MAPb₂I₇ and BA₂MA₂Pb₃I₁₀ (BA = butylammonium; MA = methylammonium), which undergo two structural phase transitions. Raman data obtained in broad temperature (360–80 K) and wavenumber (1800–10 cm⁻¹) ranges show that ordering of BA⁺ cations triggers the higher temperature phase transition, whereas freezing of MA⁺ dynamics occurs below 200 K, leading to the onset of the low-temperature phase transition. This ordering is associated with significant deformation of the inorganic sublattice, as evidenced by changes observed in the lattice mode region. Our results show, therefore, that Raman spectroscopy is a very valuable tool for monitoring the separate dynamics of different organic cations in perovskites, comprising “perovskitizer” and interlayer cations. Full article

The Rashba effect appears in the semiconductors with an inversion–asymmetric structure and strong spin-orbit coupling, which splits the spin-degenerated band into two sub-bands with opposite spin states. The Rashba effect can not only be used to regulate carrier relaxations, thereby improving the performance of photoelectric devices, but also used to expand the applications of semiconductors in spintronics. In this mini-review, recent research progress on the Rashba effect of two-dimensional (2D) organic–inorganic hybrid perovskites is summarized. The origin and magnitude of Rashba spin splitting, layer-dependent Rashba band splitting of 2D perovskites, the Rashba effect in 2D perovskite quantum dots, a 2D/3D perovskite composite, and 2D-perovskites-based van der Waals heterostructures are discussed. Moreover, applications of the 2D Rashba effect in circularly polarized light detection are reviewed. Finally, future research to modulate the Rashba strength in 2D perovskites is prospected, which is conceived to promote the optoelectronic and spintronic applications of 2D perovskites. Full article

With the rapid progress in a power conversion efficiency reaching up to 26.1%, which is among the highest efficiency for single-junction solar cells, organic–inorganic hybrid perovskite solar cells have become a research focus in photovoltaic technology all over the world, while the instability of these perovskite solar cells, due to the decomposition of its unstable organic components, has restricted the development of all-inorganic perovskite solar cells. In recent years, Br-mixed halogen all-inorganic perovskites (CsPbI3−xBrx) have aroused great interests due to their ability to balance the band gap and phase stability of pure CsPbX3. However, the photoinduced phase segregation in lead mixed halide perovskites is still a big burden on their practical industrial production and commercialization. Here, we demonstrate inhibited photoinduced phase segregation all-inorganic CsPbI1.2Br1.8 films and their corresponding perovskite solar cells by incorporating a 1-butyl-1-methylpiperidinium tetrafluoroborate ([BMP]+[BF4]−) compound into the CsPbI1.2Br1.8 films. Then, its effect on the perovskite films and the corresponding hole transport layer-free CsPbI1.2Br1.8 solar cells with carbon electrodes under light is investigated. With a prolonged time added to the reduced phase segregation terminal, this additive shows an inhibitory effect on the photoinduced phase segregation phenomenon for perovskite films and devices with enhanced cell efficiency. Our study reveals an efficient and simple route that suppresses photoinduced phase segregation in cesium lead mixed halide perovskite solar cells with enhanced efficiency. Full article

As derivatives of metal halide perovskite materials, low-dimensional metal halide materials have become important materials that have attracted much attention in recent years. As one branch, zinc-based metal halides have the potential for practical applications due to their lead-free, low-toxicity and high-stability characteristics. However, pure zinc-based metal halide materials are still limited by their poor optical properties and cannot achieve large-scale practical applications. Therefore, in this work, we report an organic–inorganic hybrid zero-dimensional zinc bromide, (TDMP)ZnBr₄, using transition metal Mn²⁺ ions as dopants and incorporating them into the (TDMP)ZnBr₄ lattice. The original non-emissive (TDMP)ZnBr₄ exhibits bright green emission under the excitation of external UV light after the introduction of Mn²⁺ ions with a PL peak position located at 538 nm and a PLQY of up to 91.2%. Through the characterization of relevant photophysical properties and the results of theoretical calculations, we confirm that this green emission in Mn²⁺:(TDMP)ZnBr₄ originates from the ⁴T₁ → ⁶A₁ optical transition process of Mn²⁺ ions in the lattice structure, and the near-unity PLQY benefits from highly localized electrons generated by the unique zero-dimensional structure of the host material (TDMP)ZnBr₄. This work provides theoretical guidance and reference for expanding the family of zinc-based metal halide materials and improving and controlling their optical properties through ion doping. Full article

The high power-conversion efficiencies of hybrid perovskite solar cells encourage many researchers. However, their limited photostability represents a serious obstacle to the commercialization of this promising technology. Herein, we present an efficient method for improving the intrinsic photostability of a series of commonly used perovskite material formulations such as MAPbI₃, FAPbI₃, Cs_0.12FA_0.88PbI₃, and Cs_0.10MA_0.15FA_0.75PbI₃ through modification with octenidine dihydroiodide (OctI₂), which is a widely used antibacterial drug with two substituted pyridyl groups and two cationic centers in its molecular framework. The most impressive stabilizing effects were observed in the case of FAPbI₃ and Cs_0.12FA_0.88PbI₃ absorbers that were manifested in significant suppression or even blocking of the undesirable perovskite films’ recrystallization and other decomposition pathways upon continuous 110 mW/cm² light exposure. The achieved material photostability—within 9000 h for the Oct(FA)_n−1Pb_nI_3n+1 (n = 40–400) and 20,000 h for Oct(Cs_0.12FA_0.88)_n−1Pb_nI_3n+1 (where n = 40–400) formulations—matches the highest values ever reported for complex lead halides. It is important to note that the stabilizing effect is maintained when OctI₂ is used only as a perovskite surface-modifying agent. Using a two-cation perovskite composition as an example, we showed that the performances of the solar cells based on the developed Oct(Cs_0.12FA_0.88)₃₉₉Pb₄₀₀I₁₂₀₁ absorber material are comparable to that of the reference devices based on the unmodified perovskite composition. These findings indicate a great potential of the proposed approach in the design of new highly photostable and efficient light absorbers. We believe that the results of this study will also help to establish important guidelines for the rational material design to improve the operational stability of perovskite solar cells. Full article

We investigate vibrations of the pyridinium cation PyH⁺ = C₅H₅NH⁺ in one-dimensional lead halide perovskites PyPbX₃ and pyridinium halide salts PyHX (X⁻ = I⁻, Br⁻), combining infrared absorption and Raman scattering methods at room temperature. Internal vibrations of the cation were assigned based on density functional theory modeling. Some of the vibrational bands are sensitive to perovskite or the salt environment in the solid state, while halide substitution has only a minor effect on them. These findings have been confirmed by ¹H, ¹³C and ²⁰⁷Pb solid-state nuclear magnetic resonance (NMR) experiments. Narrower vibrational bands in perovskites indicate less disorder in these materials. The splitting of NH-group vibrational bands in perovskites can be rationalized the presence of nonequivalent crystal sites for cations or by more exotic phenomena such as quantum tunneling transition between two molecular orientations. We have shown how organic cations in hybrid organic–inorganic crystals could be used as spectators of the crystalline environment that affects their internal vibrations. Full article

Lead halide perovskites have been widely used in optoelectronic devices due to their excellent properties; however, the toxicity of lead and the poor stability of these perovskites hinder their further application. Herein, we report a zero-dimensional (0D) lead-free organic manganese (II) bromide hybrid compound of (TBA)₂MnBr₄ (TBA⁺ = tetrabutylammonium cation) single crystals (SCs) with great environmental stability. The (TBA)₂MnBr₄ SCs show a strong green emission peak at 518 nm with a high photoluminescence quantum yield (PLQY) of 84.98% at room temperature, which is attributed to the d-d transition of single Mn²⁺ ions, as also confirmed through density functional calculation. A green light-emitting diode was produced based on (TBA)₂MnBr₄ SCs, which exhibited CIE coordinates (0.17, 0.69) close to those of standard green. A photodetector fabricated by the (TBA)₂MnBr₄ SCs shows an obvious photo response with a rapid millisecond rise/decay response time (at 365 nm). Our findings promote the research of Mn(II)-based organic–inorganic hybrid materials and pave the way by using these materials for future high-performance optoelectronic devices. Full article

In recent years, metal-halide hybrid materials have attracted considerable attention because materials, such as lead-iodide perovskites, can have excellent properties as photovoltaics, light-emitting devices, and photodetectors. These materials can be obtained in different dimensionalities (1D, 2D, and 3D), which directly affects their properties. In this article, we built 0D, 1D, and 2D manganese halide materials with 3-aminopyridine (3AP) or 4-ethylpyridine (4EtP). Two isomorphic complexes with 3AP and manganese chloride ([MnCl₂(3AP)₄]) or manganese bromide ([MnBr₂(3AP)₄]) were obtained with the amino group in 3AP assisting in the formation of 0D structures via hydrogen bonding. By modifying the reaction conditions, 3AP can also be used to build a 2D coordination polymer with manganese chloride ([MnCl₃3AP]⁻ [3APH]⁺). Unlike 3AP, 4EtP does not provide the opportunity for hydrogen bonding, leading to the formation of two additional isomorphic compounds built of individual 1D chains with manganese chloride ({MnCl₃(4EtP)₂}_n) and manganese bromide ({MnBr₂(4EtP)₂}_n). In the visible region, the 0D and 1D manganese halide compounds have similar photoluminescence properties; however, 0D and 1D have different near-IR emissions. In conclusion, hydrogen-bonding groups can play a role in the formation of discrete manganese-halide units, 1D halide chains, or 2D polymeric sheets. Full article

In recent years, there have been intense studies on hybrid organic–inorganic compounds (HOIPs) due to their tunable and adaptable features. This present study reports the vibrational, structural, and elastic properties of mixed halide single crystals of MA_xFA_1-xPbCl₃ at room temperature by introducing the FA cation at the A-site of the perovskite crystal structure. Powder X-ray diffraction analysis confirmed that its cubic crystal symmetry is similar to that of MAPbCl₃ and FAPbCl₃ with no secondary phases, indicating a successful synthesis of the MA_xFA_1-xPbCl₃ mixed halide single crystals. Structural analysis confirmed that the FA substitution increases the lattice constant with increasing FA concentration. Raman spectroscopy provided insight into the vibrational modes, revealing the successful incorporation of the FA cation into the system. Brillouin spectroscopy was used to investigate the changes in the elastic properties induced via the FA substitution. A monotonic decrease in the sound velocity and the elastic constant suggests that the incorporation of large FA cations causes distortion within the inorganic framework, altering bond lengths and angles and ultimately resulting in decreased elastic constants. An analysis of the absorption coefficient revealed lower attenuation coefficients as the FA content increased, indicating reduced damping effects and internal friction. The current findings can facilitate the fundamental understanding of mixed lead chloride perovskite materials and pave the way for future investigations to exploit the unique properties of mixed halide perovskites for advanced optoelectronic applications. Full article