Next Article in Journal
Langmuir and Langmuir–Blodgett Monolayers from 20 nm Sized Crystals of the Metal–Organic Framework MIL-101(Cr)
Next Article in Special Issue
Influence of N2/Ar Flow Ratio on the Microstructure and Electrochemical Capacitive Performance of TiN Thin-Film Electrodes for Micro-Supercapacitors
Previous Article in Journal
Study on the Degradation, Wear Resistance and Osteogenic Properties of Zinc–Copper Alloys Modified with Zinc Phosphate Coating
Previous Article in Special Issue
Effect of Nd:YAG Nanosecond Laser Ablation on the Microstructure and Surface Properties of Coated Hardmetals
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Coatings
Volume 15
Issue 12
10.3390/coatings15121448
coatings-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum

by
Xingfa Ma
1,*,
Xintao Zhang
1,
Mingjun Gao
1,
Ruifen Hu
2,
You Wang
2 and
Guang Li
2
1
School of Environmental and Material Engineering, Center of Advanced Functional Materials, Yantai University, Yantai 264005, China
2
National Laboratory of Industrial Control Technology, Institute of Cyber-Systems and Control, Zhejiang University, Hangzhou 310027, China
*
Author to whom correspondence should be addressed.
Coatings 2025, 15(12), 1448; https://doi.org/10.3390/coatings15121448
Submission received: 23 October 2025 / Revised: 19 November 2025 / Accepted: 5 December 2025 / Published: 8 December 2025
(This article belongs to the Special Issue Research Progress and Prospect of Functional Thin Films & Hard Protective Coatings)
Browse Figures
Versions Notes

Abstract

To increase the use of the near-infrared (NIR) light from In2O3, a nanocomposite of In2O3/reduced graphene oxide was synthesised. To improve adhesion to the substrates, a small amount of PVA (polyvinyl alcohol) was added to the nanocomposite. Results showed that adding an appropriate amount of PVA to the nanocomposite remarkably enhanced the ability to extract photogenerated carriers due to interface optimisation based on the grain boundary filling with PVA and charge tunnelling effects. The nanocomposites exhibited photoconductive switching responses from the visible light region to the near-infrared range. Meanwhile, the organic/inorganic hybrid coating on silk fibres exhibited mutual conversion of positive and negative photoconductivity, as well as electrical switching responses to applied strain. Furthermore, it was found that a photoelectric signal could still be determined with zero bias after the In2O3/reduced graphene oxide nanocomposite had been stored for over four years. This reflects that the nanocomposites have an internal electric field that promotes the transfer of photogenerated carriers and prevents the recombination of photogenerated electrons and holes. Similar results were also obtained by adding an appropriate amount of other non-conjugated polymers, such as dendrimers. Physical mechanisms are discussed. This study provides reference values for the development of multifunctional organic/inorganic hybrids integrating non-conjugated polymer components to enhance specific properties.

1. Introduction

Among functional oxides, In2O3 is one of the most important n-type semiconductors, with an approximate bandgap of 2.7 eV. Due to its grain boundary effects and surface or interface characteristics, In2O3 and its nanocomposites have found widespread application in gas sensors for the detecting various gases, including formaldehyde [1,2,3,4,5,6,7,8], triethylamine [9,10], nitric oxide [11,12,13,14,15,16,17,18], xylene [19], acetone [20], ethanol [21], hydrogen [22,23,24], isoprene [25], toluene [26], CO2 [27], CH4 [28], n-butanol [29], glucose [30], and exhaled biomarkers [31]. In addition to the fields of gases and biosensors, one of the hotspot fields of In2O3 is photosynthesis, including photocatalytic CO2 reduction [32,33,34,35], visible light-triggered photocatalytic hydrogen evolution [36,37], photocatalytic nitrogen reduction under solar light irradiation [38], and photocatalytic degradation [39,40,41,42]. Furthermore, applications include photodetectors [43,44,45], transistors [46,47], photosensitive resistive memory devices [48], supercapacitors [49], fuel cells [50], lithium-ion batteries [51,52,53], solar cells [54], and so on.
The physical and chemical properties of materials originate from their electronic structures. By tailoring the electronic behaviour of materials, it is possible to remotely control the performance of designed materials based on the interaction of light and matter. Regarding the modification of In2O3 and its nanocomposites, most studies focus on gas sensors and applications in photosynthesis. The materials systems include rare-earth-doped indium oxide [1]; defect manipulation [2]; Au, Ag, Pd, Pt, and Cu clusters; Zn-doped, Ce-doped, Y-doped, Ru-doped, Fe-doped, Tb-doped, Ni-modified, Co-doped [3,4,5,12,19,20,22,25,34,40,42], Sn- and Fe-Co doped, vanadium-doped [55], as well as various heterojunction, core–shell structure, and quantum dot-decorated materials; phase control [56], oxygen vacancy tailoring [57,58,59,60], interfacial electron transfer and photoelectron transfer [61,62], and the modulation of hole and electron accumulation [63,64]; interfacial electronic interaction in organic/inorganic hybrids [65]; and plasmonic characteristic modulation [66]. Optimising the interfaces, grain boundaries, and defects in nanocomposites enhances their multifunctionality and widens their applications in multidisciplinary fields.
To narrow the band gap width of In2O3 and utilise broadband light fully, landmark progress involving doping, defect engineering, and interface engineering is presented here. Gu and co-workers [2] manipulated the point defect (VO) of In2O3 for formaldehyde detection. Wang and co-workers [19] reported on the use of oxygen vacancy-rich, Ru-doped In2O3 nanosheets for the detection of xylene. Zhao and co-workers [36] tailored the oxygen defect in black In2O3−x/In2O3 to boost photocatalytic hydrogen evolution. Alsaif and co-workers [43] reported a 2D SnO/In2O3 van der Waals heterostructure photodetector. Zhao and co-workers [62] enhanced the interfacial electron transfer through the introduction of asymmetric Cu-Ov-In sites on In2O3. Wang and co-workers [64] tuned the surface electron accumulation of In2O3 by adsorbing molecular electron donors and acceptors. Zhu and co-workers [65] studied the interfacial electronic interactions in In2O3/poly (3,4-ethylenedioxythiophene)-modified carbon heterostructures. Yang and co-workers [66] modulated the plasmonic characteristics of In2O3 for photocatalytic H2 evolution. Fang and co-workers [67] tuned the plasmon resonance of In2O3 via electron activation and trapping. Yang and co-workers [68] enhanced surface charge localisation over nitrogen-doped In2O3. Isakov and co-workers [69] studied quantum confinement and thickness-dependent electron transport in In2O3 transistors. Liang and co-workers [70] optimised the interfaces of the In2O3-decorated ZnO/reduced graphene oxide/ZnS heterostructure to create a robust internal electric field. Yin and co-workers [71] studied the mechanism of excitonic splitting in In2O3 by carrier delocalisation. Nath and co-workers [72] conducted an in-depth analysis of the switching response of n-Si/In2O3 NW/Ag NPs/In-based devices. Bhuvaneswari and co-workers [73] fabricated p-Si/n-In2O3 and p-Si/n-ITO junctions for use in optoelectronic devices, etc.
A review of the progress of In2O3-based nanocomposites reveals that most of the research on In2O3 generally involves oxygen vacancy modulation, multi-element doping, interface engineering, surface functionalisation, and heterostructures. The construction of In2O3-based component heterostructures is a commonly employed modification approach which utilises a variety of other components, including metal oxides, metal sulphides, metals, carbon materials, polymers, and small organic molecules. In2O3/carbon nanohybrids are of particular interest due to their ability to facilitate charge transfer at the interface between In2O3 and carbon materials thanks to the controlled conductivity of carbon materials. They prevent the recombination of photogenerated carriers, sustainably generating photogenerated electrons and holes, and widening applications in interdisciplinary fields.
Of all the carbon materials, graphene oxide has received a great deal of attention thanks to its excellent conductivity and low cost. It is widely used in new materials and various devices, as well as in interdisciplinary fields. In the near-infrared (NIR) region, graphene oxide has little absorbance, and the intensity of this absorbance is very weak. Integrating other components is still required to enhance its performance. Meanwhile, the large number of defects in graphene oxide also endows it with excellent chemical properties, enabling it to participate in important chemical reactions. However, these defects generally hinder charge transfer for physical signal measurement. Although In2O3-based nanocomposites have been used in photodetectors [43,44,45], achieving a NIR response remains a significant challenge. Therefore, interface engineering could solve these key problems. In2O3 and graphene oxide show promise in achieving complementary properties.
As many nanocomposites exhibit multifunctionality, several physical mechanisms coexist, resulting in interdisciplinary applications. Drawing on our past studies, as well as our understanding of gas and light sensitivity, we have identified numerous similar physical mechanisms arising from electronic effects in materials. Over the past ten years, Ma and his colleagues have shifted their focus to studying the photocurrent switching behaviours of various heterostructures within the broadband light spectrum, based on the electronic interactions at the interfaces of multiple components [74]. As there are many photocurrent switching phenomena in nature and light is an important energy resource, this is a suitable method for controlling the properties of materials or devices in a non-contact mode. Modulating the accumulation behaviour of holes and electrons can effectively tailor the physical and chemical properties of materials. Therefore, controlling the behaviour of electrons in composites using light from different wavelengths is particularly important for developing new materials and interdisciplinary applications. Wang [75] previously reported on the remote control of a material’s spin degree by constructing a tunnel junction that can be used for information storage. This idea is highly intriguing, as it demonstrates a method of tailoring the properties of nanocomposites through the tunnelling effects of non-conjugated polymers. In the field of stimuli-responsive materials, typical external field sources include light, electrical, magnetic, force, and pH fields. Interaction between light and matter involves complex photodynamic processes, bandgap engineering, defects and interfaces in materials. Consequently, the development of near-infrared-responsive materials shows great promise for multidisciplinary applications.
From a materials science perspective, although the constituent components of composites are finite, the combination of different components, dimensions, sizes, and phases are infinite. The development of new materials relies primarily on these combinations. Polymeric materials are an important component in the design of nanocomposites. Conductive and optoelectronic polymers are typical conjugated polymers. The conjugated polymers have poor flexibility. The non-conjugated polymers have tailored flexibility but poor conductivity. Combining inorganic functional materials with non-conjugated polymers can achieve complementary behaviour by utilising tunnel effects. This study examines the interaction at the interface of In2O3/reduced graphene oxide to narrow the bandgap of In2O3. Adding a small amount of non-conjugated polymers achieved defect passivation and improved adhesion to certain substrates. The electron/hole separation and extraction capabilities of the In2O3/reduced graphene oxide/non-conjugated polymer nanocomposite were examined under the excitation of low-power light at wavelengths of 405, 650, 780, 808, 980, and 1064 nm. The resulting nanocomposite exhibited good photocurrent signals across a broad spectrum of light. When the organic/inorganic hybrid was simultaneously coated on silk fibres, a transformation from positive to negative photoconductivity and electrical switching responses to applied strain was observed. These results are also valuable for interdisciplinary research and investigating the interaction between light and matter. As the extraction of photogenerated electrons and holes is significant in many fields, and the recombination of photogenerated carriers presents a major challenge, improving the charge transport of nanocomposites can mitigate this issue. Therefore, research in this area continues to hold considerable reference that is value for multidisciplinary studies.

2. Materials and Methods

2.1. Materials

Indium chloride (AR, i.e., Analytical Reagent), MACKLIN Biochemical Co., Ltd. (Shanghai, China) Hexamethylenetetramine (AR), Tianjin Ruijin Chemical Reagent Co., Ltd., Tianjin, China. PVA (polyvinyl alcohol) with a content of ≥97% wt., Tianjin DAMAO Chemical Reagent Factory, Tianjin, China. PAMAM, G3 (CYD-130A) dendrimers, Weihai Chenyuan Molecular New Materials Co., Ltd., Weihai, China; the number of the -NH2 group is 32 and the molecular formula is C302H606N122O60. Potassium permanganate (AR), Yantai Sanhe Chemical Reagent Co., Ltd., Yantai, China. Sulphuric acid (AR), Yantai Laiyang Fine Chemical Factory. Nitric acid (AR), Yantai Sanhe Chemical Reagent Co., Ltd.

2.2. Preparation of Graphene Oxide

Graphene oxide was synthesised according to our previous report [76].

2.3. Preparation of Polymer Solution

PVA solution: Amounts of 1 g of PVA and 200 mL of H2O were added and stirred for 30–50 min. A PVA solution was obtained for later use.
Dendrimer solution: Amounts of 1 g of G3 dendrimers and 500 mL of H2O were added and stirred for 10–30 min. A G3 solution was obtained for later use.

2.4. Preparation of In2O3/Reduced Graphene Oxide

The experimental process is as follows.
(1) Amounts of 50 mL of H2O, 10 mL of graphene oxide solution (with a concentration of about 2.6 mg/mL), 0.5 g of indium chloride, and 1 g of hexamethylenetetramine were added and stirred for 5–10 min. The hydrothermal reaction condition and sample treatment were similar to our previous report [77]. The reaction condition was set to 160 °C for 5–6 h. The sample was labelled as In2O3/r-G (10 mL).
(2) Amounts of 40 mL of H2O, 20 mL of graphene oxide solution (with a concentration of about 2.6 mg/mL), 0.5 g of indium chloride, and 1 g of hexamethylenetetramine were added and stirred for 5–10 min. The hydrothermal reaction condition and sample treatment were similar to our previous report [75]. The reaction condition was set to 160 °C for 5–6 h. The sample was labelled as In2O3/r-G (20 mL).
(1), (2) The experiments were repeated several times for later use.

2.5. Preparation of In2O3/Reduced Graphene Oxide/PVA Hybrid and Silk Fibres Coated with In2O3/Reduced Graphene Oxide/PVA Suspension

The In2O3/r-G (10 mL) and In2O3/r-G (20 mL) synthesised in Section 2.4, as well as 10 mL of PVA solution, were added and stirred for 5–10 min. The In2O3/reduced graphene oxide/PVA suspension was then obtained.
Since PVA adheres well to silk fibres, an appropriate quantity of silk fibres was soaked in the In2O3/reduced graphene oxide/PVA suspension for 3–5 min. The fibres were then removed and left to dry at room temperature.

2.6. The Characterisations of SEM, UV–Vis-NIR, Raman, and XRD

The SEM, UV–Vis-NIR, Raman, and XRD characterisations were the same as in our previous report [75]. Instruments used included the ZEISS Gemini SEM300 (Oberkochen, Germany), TU-1810 spectrophotometer (Beijing Puxi General Instrument Co., Ltd., Beijing, China), PHS-3C confocal Raman spectrometer (HORIBA, Kyoto, Japan), and XRD-7000 from SHIMADZU (Shimadzu, Kyoto, Japan).

2.7. Photocurrent Response of Nanocomposite to the Visible Light and the NIR

The photocurrent signal measurement of the resulting nanocomposite to the visible light and part of the NIR was similar to our previous report [74,77,78]. Au gap electrodes on PET film and Ag fibre electrodes (integrated with conductive adhesive) on A4 printing paper substrate were used in this experiment. The resulting nanocomposite suspension was cast onto the gap electrodes and dried at room temperature. Excited light wavelengths were as follows: 405, 650, 780, 808, 980, and 1064 nm. Due to the poor electrical conductivity of the polymer employed, if photoconductive signals are to be obtained from the In2O3/reduced graphene oxide/PVA hybrid in this experiment, the photoconductive properties of the silk fibres coated with In2O3/reduced graphene oxide/PVA have to be investigated further. The structure of the electrodes is shown in Scheme 1.

2.8. Electrical Response of Nanocomposite to the Force Applied

The electrical response signal measurement of the resulting nanocomposite to the force applied was similar to our previous report [74].

3. Results and Discussion

3.1. Photoelectrical Signal Comparison Between the In2O3/Reduced Graphene Oxide and the In2O3/Reduced Graphene Oxide/PVA Hybrid

The experiment revealed that it was difficult to characterise the photocurrent signal for the In2O3/r-G nanocomposites with different amounts of reduced graphene oxide. The baseline noise was also very high. This is primarily due to the numerous defects in the nanocomposites, significant scattered noise, and obstructed charge transport pathways. However, adding an appropriate amount of PVA markedly enhanced both the photoelectric signal and baseline stability. Based on the studies of the optoelectronic signal results, the fundamental characterisation of the nanocomposite is as follows. The representative SEM (scanning electron microscope) image of the In2O3/reduced graphene oxide/PVA hybrid is shown in Figure 1.
As shown in Figure 1, most of the morphologies at different magnifications (Figure 1A,B) were nanoparticles with sizes of about 10 nm or so. These nanoparticles should be In2O3. A small amount of lamellar and nanocube morphologies were also observed. As shown in the surface of the fracture (Figure 1B,C), a polymer wire drawing phenomenon was clearly observed.
The XRD results of the resulting nanocomposites are shown in Figure 2.
As shown in Figure 2, the diffraction peaks of the resulting nanocomposites are, overall, relatively weak and exhibit considerable noise. No characteristic doughnut-shaped peaks, which are typical of amorphous materials, were observed. Compared with the XRD results of In2O3-r-G (10) and In2O3-r-G (20), increasing the amount of graphene oxide did not result in any significant changes to the XRD pattern (Figure 2A). Similarly, compared with the XRD results of In2O3-r-G (10) and In2O3-r-G (10)-PVA (10 mL), the addition of an appropriate amount of PVA polymer also did not result in any significant changes to the XRD pattern of In2O3-r-G (10)-PVA (10 mL), as shown in Figure 2B. Despite the considerable noise, some diffraction peaks can still be discerned. The material can be characterised qualitatively. The diffraction peaks at 22.51°, 45.65°, 52.34°, 57.62°, and 71.01° are the peaks of the (012), (024), (122), (214), and (306) planes of In2O3 (PDF# 22-0336), respectively. Therefore, the resulting nanocomposite contains an In2O3 component.
Due to the presence of a large number of defects for graphene oxide, the Raman spectra of In2O3-r-G (10)-PVA (10 mL) were examined. The results are shown in Figure 3.
As shown in Figure 3, it is found that a wide band corresponding to the D band of carbon defects was visible at 1321 cm−1 or so. A wide band of the D band implies the existence of multiple types of defects. The wavenumber at 1586 cm−1 or so also showed a wide band, which belongs to the G band of the carbon sp2 hybrid. The intensity of the D band is higher than that of the G band. This illustrates that the defects of the reduced graphene oxide are outstanding, which require defect passivation for the physical signal determination.
The UV–Vis-NIR absorbance curve of the In2O3-r-G-PVA nanocomposite is shown in Figure 4.
As shown in Figure 4, the absorbance of the organic/inorganic nanocomposites covers the entire visible light spectrum and part of the near-infrared (NIR) region. The optical absorbance is hardly affected by the amount of graphene oxide and PVA addition. Effective absorption is a crucial prerequisite for obtaining photoelectric signals. Absorbance in the broadband light spectrum is advantageous for the use of near-infrared light. The absorption curve provided here is for reference only. The subsequent measurement of the photoelectric signal is the crucial factor. Therefore, the transient state photocurrent response to the weak visible light was examined based on Ag fibre gap electrodes (integrated with conductive adhesive) on paper substrate. The results are shown in Figure 5.
As shown in Figure 5, In2O3/r-G (10 mL) exhibits a negative photoconductive response when exposed to the weak visible light, primarily due to the capture of photogenerated electrons by material defects (as shown in Figure 5A). Due to the donor or acceptor electron effect of different defects, the concentration of photogenerated electrons is lower than the concentration of electrons captured by material defects, resulting in a negative photoconductive response. Both positive and negative photoconductivity depend on the electronic effects of defects and their concentration levels. As the amount of reduced graphene oxide increases, the response changed to a positive photoconductive response (as shown in Figure 5A,C). Increased conjugated systems enhance photogenerated charge transport by increasing the content of reduced graphene oxide in the nanocomposite. This results in a concentration of photogenerated electrons that exceeds that of electrons captured by material defects. Although the In2O3/r-G nanocomposites (as shown in Figure 5A,C) exhibited photoconductive behaviour, their stability was very poor and the photoelectric signals were difficult to obtain. The main reason for this is as follows. Firstly, there is a large number of defects in the nanocomposite. This is also evident in the Raman spectra of the nanocomposites (Figure 3). Apart from carbon defects (see Figure 3), other defects also significantly hinder the extraction of photocurrent. The scattered noise caused by these defects is substantial, making it difficult to extract the photoelectric signal. Another reason is that the reduced graphene oxide is highly hydrophobic. This leads to poor interface contact with the In2O3 nanoparticles and paper substrate, resulting in a difficult-to-measure physical signal due to poor charge transfer. Therefore, some hydrophilic components need to be added to improve the interface interaction. Since PVA has a large number of –OH groups and good adhesive properties with regard to In2O3 nanoparticles and the paper substrate, a small amount of PVA was added to the nanocomposites. As shown in Figure 5A,B, the addition of PVA clearly enhances the extraction ability of photogenerated carriers, and the transformation phenomenon from negative to positive photoconductivity is also observed (as shown in Figure 5A,B). The hydroxyl group of PVA coordinates with metal cations in the nanocomposite, passivating some acceptor defects, regulating the electronic effects of defects, and improving the extraction of photogenerated electrons. This demonstrates that the effect of PVA on defect passivation is clear. On the other hand, PVA’s favourable adhesive properties enhance the bonding strength to the substrate and decrease the distance between grain boundaries. This improves charge transport pathways and facilitates the transport of photogenerated carriers through the tunnelling effect. As shown in Figure 5C,D, the addition of PVA clearly improved the extraction ability of the photogenerated carriers and the stability of the photocurrent and baseline current. The effects of defect passivation by PVA are also evident.
In short, the comparative results above clearly show that it is difficult to obtain a photocurrent signal for the In2O3/r-G (10 and 20 mL) nanocomposites and that there is also a lot of noise (Figure 5A,C). However, adding an appropriate amount of PVA markedly improved both the photoelectric signal and baseline stability (Figure 5B,D). As PVA is a non-conductive polymer, this phenomenon can only be explained by the tunnelling effect. The tunnelling effect manifests as microscopic particles (such as electrons) penetrating potential barriers of finite width via their wave functions, thereby exhibiting quantum behaviour. Although non-conjugated polymers are non-conductive, photogenerated electrons can penetrate non-conjugated polymers of finite width via wave functions, thereby enabling charge transport. Therefore, the appropriate addition of non-conjugated polymers facilitates the separation and transport of photogenerated carriers. This is a low-cost, environmentally friendly approach to passivating the defects in oxide-based nanocomposites to enhance their optoelectronic properties. Therefore, integrating a suitable amount of non-conjugated polymers into nanocomposites can complement the properties of the components.
In interdisciplinary fields, 650, 808, and 980 nm are important light sources. In this study, 100 mW at 650 nm, 200 mW at 808 nm, and 200 mW at 980 nm were selected as typical light sources to investigate the photocurrent responses of the In2O3-r-G-PVA. The results are shown in Figure 6, Figure 7 and Figure 8.
A comparison of the results in Figure 6A,B shows that the On/Off ratio to 100 mW of 650 nm light was clearly enhanced by the addition of an appropriate amount of PVA. The stability of the photocurrent and baseline current was also improved. This is primarily due to the addition of an appropriate amount of non-conjugated polymer, which reduces scatter noise and improves the extraction of photogenerated charge.
As shown in Figure 7A,B, the loading of PVA clearly enhances the ability to extract photogenerated electrons. The transformation from negative to positive photoconductivity was also observed with 200 mW of 808 nm light source due to PVA-induced defect passivation. Figure 7C,D show that PVA loading also clearly improves the extraction of photogenerated electrons and the stability of photocurrent and baseline current. These results are similar to those observed for visible light (Figure 5). These results demonstrate the effectiveness of defect passivation by PVA.
As shown in Figure 8A,B, the loading of PVA clearly enhanced the ability to extract photogenerated electrons. The transformation phenomenon from negative to positive photoconductivity was also observed with a 980 nm light source of 200 mW due to defect passivation by PVA. The On/Off ratio, response ratio, and stability of photocurrent and baseline current increased significantly. This is similar to the results obtained using visible light (Figure 5). This illustrates that the number of defects with different levels in In2O3/r-G (10 mL) is much larger than that in In2O3/r-G (20 mL). It also shows that a large number of defects were present at the grain boundary of In2O3 nanoparticles. The results demonstrate that the defect passivation by PVA is effective and simple. Therefore, the photocurrent responses of organic/inorganic hybrids were explored using some typical light sources with lower power. The dependence of the photoelectric signal on the incident light power and the repeatability were also studied. The representative results are shown in Figure 9 and Figure 10.
As shown in Figure 9A,B, the In2O3/r-G (10 mL)/PVA (10 mL) nanocomposite exhibited good photocurrent responses when exposed to light sources of 20 mW at 650 nm and 50 mW at 980 nm. There is a clear positive correlation between the switching ratio and the power of the incident light.
As shown in Figure 10, the resulting organic/inorganic hybrid exhibited good repeatability with 200 mW of a 980 nm near-infrared (NIR) light source. It also exhibited good repeatability with other light sources, such as 808 nm of NIR and weak visible light. Due to space constraints, these results are not presented here.
The results of the above study also support those of the UV–Vis-NIR curve (Figure 4). They demonstrate that the prepared nanocomposite exhibits a good response in the near-infrared region. However, the influence of light scattering was present in the UV–Vis-NIR experiment. The UV–Vis-NIR curve is provided for reference only; the key factor is the support of the photoelectric signal obtained. Scattering factors may also lead to increased absorption. The experimental results indicated that the spectral and photoelectric signals are in agreement. Pursuing a purely absorption spectrum is not necessarily essential during the research process, depending on the content of the research. In fact, photoelectric signal extraction also involves contributions from the scattering process.
In short, studies employing multi-wavelength light excitation (e.g., 650 nm, 808 nm, 980 nm, etc.) have demonstrated that extracting photoelectric signals is clearly enhanced by adding an appropriate amount of PVA. The stability of the photocurrent and baseline current was also improved. This is primarily because adding an appropriate amount of non-conjugated polymer reduces scatter noise, tailors the electronic effects of defects, and improves the extraction of photogenerated carriers.

3.2. Photoelectrical Signal and Other Physical Property Studies of the In2O3/Reduced Graphene Oxide/PVA Hybrid Coated on the Silk Fibres

The findings of the above research show that the In2O3/r-G (10 and 20 mL)/PVA (10 mL) nanocomposites exhibit broadband extraction of photoelectric signals. Since the In2O3/r-G (10 and 20 mL)/PVA (10 mL) nanocomposites show good adhesion to certain substrates, and several fibres are often used as substrates for flexible and wearable devices [79,80,81], the photocurrent signals of the In2O3/r-G (10 and 20 mL)/PVA (10 mL) as a coating deposited on the silk fibres were examined. The representative results are shown in Figure 11 and Figure 12.
Figure 11A shows in detail that, when the In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre was exposed to 100 mW of a 650 nm light source, the photocurrent increased sharply in the first stage (about 6.7 s) and then decreased. This is because the concentration of photoelectrons generated in the initial stage far exceeds that of captured electrons. Subsequently, the photoelectrons diffuse to the silk fibre surface. Silk fibre is well known to be a protein, a product of amino acid polymerisation. Silk fibre contains a large number of O and N groups. These chemical groups easily capture the photogenerated electrons. Therefore, the photocurrent first increases and then decreases. Similarly, when the In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre was exposed to 100 mW of a 650 nm light source, the photocurrent increased sharply in the first stage (about 2.3 s) and then decreased (as shown in Figure 11B). When the In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre was exposed to 200 mW of a 808 nm light source, the photocurrent increased sharply in the first stage (about 4.7 s) and then decreased (as shown in Figure 11C). When the In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre was exposed to 200 mW of an 808 nm light source, the photocurrent increased sharply in the first stage (about 6.7 s) and then decreased (as shown in Figure 11D). When the In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre was exposed to 200 mW of a 980 nm light source, the photocurrent increased sharply in the first stage (about 2.5 s) and then decreased (it is shown in Figure 12A). When the In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre was exposed to 200 mW of a 980 nm light source, the photocurrent increased sharply in the first stage (about 3.6 s) and then decreased (as shown in Figure 12B).
As shown in Figure 11 and Figure 12, the In2O3/r-G (10 and 20 mL)/PVA (10 mL) on silk fibres exhibited a transformation phenomenon from positive to negative photoconductivity to the visible light, 100 mW of 650 nm, 200 mW of 808 nm, and 200 mW of 980 nm light sources. This is mainly due to the integration of the silk fibre into the nanocomposites. Silk fibre contains a large number of O and N groups. These chemical groups easily capture photogenerated electrons. Consequently, the photocurrent initially increased and then decreased. When the light source is switched off, the captured photoelectrons are gradually released, causing the current to increase once more. It is evident that defects in the substrate play a significant role in the capture of photoelectrons. Substrate factors must not be overlooked when extracting optoelectronic signals. Since photocurrent extraction is the combined result of multiple factors, such as bandgap engineering, defects, interfaces and substrates, etc., these research findings provide reference for defect information in the substrate.
Since the In2O3/r-G (10 and 20 mL)/PVA (10 mL) nanocomposites belong to an organic/inorganic hybrid with a soft lattice, the nanocomposites respond to applied force. The force sensitivity of the organic/inorganic hybrid was preliminarily examined. The representative results are shown in Figure 13.
As shown in Figure 13, the In2O3/r-G (10 and 20 mL)/PVA (10 mL) nanocomposites were found to respond to the applied force. When a certain compression force was applied to the film, the film current increased. Conversely, when the force was released, the film current decreased. This is mainly because when a compression force is applied, the distance between the nanoparticles is shortened, which increases the film current. Conversely, when the force was released, the distance between the nanoparticles increased, resulting in a decrease in the film current. Additionally, the applied force affects the bandgap width of certain functional materials. This work does not discuss this issue in detail; it is merely a preliminary characterisation.

3.3. Photoelectrical Signal Study of the In2O3/Reduced Graphene Oxide Being Stored for Several Years and the In2O3/Reduced Graphene Oxide Modified with Other Non-Conjugated Polymers

Due to their surface activity, nanocomposites readily absorb extraneous species and may undergo oxidation during storage, such as absorbing oxygen or moisture from the air. This can impair the extraction of photogenerated charges and affect their chemical properties. Therefore, after the In2O3/r-GO nanocomposites were stored for over 4 years at room temperature, they were coated onto the Au gap electrodes of the PET film substrate. Afterwards, the In2O3/r-GO and In2O3/r-GO nanocomposites treated with dendrimers (G3) containing -NH2 groups (the dendrimer (G3) solution was cast on the In2O3/r-GO thick film and dried at room temperature) were examined again using light sources with wavelengths of 405, 650, 780, 808, 980, and 1064 nm. The resulting nanocomposites and modified products exhibited broadband optoelectronic signal extraction, although the light excitation varied across different wavelengths. Due to space constraints, only some representative results are presented below.
Figure 14 shows that the In2O3/r-G (10 and 20 mL) nanocomposites exhibited clear photocurrent responses with a 0 V and 1 V bias when exposed to 808 nm (200 mW) and 980 nm (100 mW) light sources. This demonstrates that the In2O3/r-G (10 and 20 mL) nanocomposites present interfaces, and interfacial interaction produces a strong internal electrical field, which enhances photocurrent extraction. Figure 14D also shows that the In2O3/r-G (20 mL) nanocomposite had a relatively stable photocurrent response and baseline current. This indicates that the In2O3/r-G (20 mL) nanocomposite possesses a relatively low defect concentration at 1.26 eV or so, thereby reducing the likelihood of capturing photogenerated electrons.
Since the PAMAM dendrimers used in the study have some outstanding characteristics, such as good dispersing ability, and inclusive characteristics, it can effectively disperse nanomaterials to prevent their aggregation. The In2O3/r-G (10 and 20 mL) nanocomposite casting thick films were coated with a PAMAM dendrimer solution. After drying, the In2O3/r-G (10 and 20 mL) nanocomposites treated with dendrimers (G3) were examined in a similar way. The representative results are shown in Figure 15, Figure 16, Figure 17, Figure 18 and Figure 19.
Compared with Figure 14 and Figure 15, it is clear that the In2O3/r-G (10 and 20 mL) treated with dendrimers (G3) decreases the capture of photogenerated electrons and improves photocurrent extraction. This demonstrates that adding an appropriate amount of dendrimer polymer can reduce the capture of photogenerated electrons by certain defects. This is related to the presence of oxygen and nitrogen groups within the dendrimer (G3) polymer. These functional groups coordinate with metal cations in the nanocomposite, passivating certain defects with acceptor effects, tailoring the electronic effects of defects, and thereby enhancing the extraction of photogenerated electrons. Applying a bias enhances the stability of the baseline current and photocurrent, thereby promoting the transfer the photogenerated carriers. Therefore, incorporating small amounts of non-conjugated polymer components into functional nanocomposites contributes to performance enhancement. Given the abundance of non-conjugated polymer systems and their strong design potential, this research is expected to expand their applications in the field of advanced functional nanocomposites, and to fully exploit the flexibility of non-conjugated polymers and their tunnelling effect at interfaces.
As shown in Figure 16, it is found that the In2O3/r-G (20 mL) and In2O3/r-G (20 mL) treated with dendrimers (G3) to a 1064 nm (20 mW) light source still clearly exhibited photocurrent responses at 0 V and 1 V biases. This demonstrates that the prepared nanocomposite exhibits a pronounced photoconductive response in the near-infrared region (such as 808, 980, and 1064 nm light sources), achieving the anticipated effect of In2O3 modification. Therefore, the near-infrared utilisation of In2O3 can be extended through interface engineering.
The dependence of the photoelectric signal of representative light sources on the incident power is shown in Figure 17, Figure 18 and Figure 19.
As shown in Figure 17, the photoelectric signal of the representative light sources clearly depends on the incident power of 980 nm with a bias of 0 V and 1 V. The In2O3/r-G (10 mL) treated with dendrimers (G3) to a 980 nm (5 mW) light resource still exhibited a little photoelectric signal with 0 V and 1 V biases (as shown in Figure 17B,D). Under a 1 V bias, the baseline current is more stable (as shown in Figure 17C). This demonstrates that applying a bias further promotes the separation and transport of photogenerated carriers. The In2O3/r-G (20 mL) treated with dendrimers (G3) to 980 nm (100, 50, and 5 mW) light sources also has some similar trends. These are shown in Figure 19B–D.
As shown in Figure 18, the photoelectric signal of the representative light source also clearly depends on the incident power of 980 nm with 0 V and 1 V biases for the In2O3/r-G (20 mL) nanocomposite. The In2O3/r-G (20 mL) exposed to a 980 nm (5 mW) light source still exhibited a good photoelectric signal with 0 V and 1 V biases. This is due to an increase in conjugated systems in the nanocomposite caused by an increase in the content of reduced graphene oxide.
In short, the above research demonstrates that this nanocomposite can extract optoelectronic signals across a broad spectrum. This is primarily due to bandgap, interface, and defect engineering within the material. Naturally, this is closely related to the material’s electronic structure. Since the bandgap of indium(III) oxide (In2O3) is approximately 2.7 eV, the resulting organic/inorganic hybrid exhibits good optoelectronic properties from the visible light region to the near-infrared (NIR) range. Defect and impurity levels clearly play a significant role. The built-in electric field, which is generated by interfacial interactions, promotes exciton separation and the directional transport of photogenerated carriers, thereby generating photocurrent. The efficient transport of photogenerated electrons and holes in nanocomposites is facilitated by interface optimisation and tunnelling effects. Otherwise, improving the charge transport properties of nanocomposite can effectively suppress the recombination of photogenerated electrons and holes. Preventing the recombination of photogenerated carriers is a common key technology across multiple disciplines. This study reports on photogenerated charge transport in the functional nanocomposites containing non-conjugated polymer components within a broadband spectrum range. It is hoped that this work may serve as a reference for multidisciplinary fields.

4. Conclusions

In summary, this study examined the light-induced interfacial charge transport in In2O3/r-G/non-conjugated polymer hybrids. The strong interface interaction between the In2O3 nanoparticles/reduced graphene oxide produces an internal electric field that avoids the recombination of photogenerated electrons and holes. Meanwhile, filling the grain boundaries with an appropriate amount of non-conjugated polymers improves adhesion and photoelectric signal acquisition over a wide range of light excitation. Defects in the substrate play a significant role in capturing photoelectrons. Therefore, substrate factors must not be overlooked when extracting optoelectronic signals. Otherwise, the synthesised nanocomposite could respond to applied force. Various physical mechanisms were discussed. This illustrates that the appropriate addition of non-conjugated polymers to a nanocomposite can enhance the ability to extract photogenerated carriers and achieve complementary performance through interface optimisation. This low-cost, environmentally friendly approach optimises the grain boundaries of oxide-based nanocomposites, enabling the generation of a photocurrent signal across a broad spectrum of light. This approach is useful for studying the photodynamic process and the mechanism of light–matter interaction, particularly in nanocomposites containing soft/hard interfaces. This could provide a basis for expanding the use of non-conjugated polymers in advanced functional nanocomposites.

Author Contributions

Conceptualisation, methodology, investigation, writing—original draft preparation, writing—review and editing, funding acquisition, resources, and investigation, X.M.; investigation, X.Z., M.G., R.H. and Y.W.; resources, G.L.; all authors analysed the data; all authors discussed the results of the paper. All authors have read and agreed to the published version of the manuscript.

Funding

This project was supported by the Natural Science Foundation of Shandong Province (project no. ZR2013EMM008).

Institutional Review Board Statement

This study did not involve any ethical issues.

Informed Consent Statement

Not applicable.

Data Availability Statement

The data presented in this study are available upon request from the corresponding author. The data are not publicly available due to privacy issues.

Acknowledgments

Thanks to You Wang and Guang Li of Zhejiang University for the fabrication of several electrodes and for checking the English in the paper. SEM and Raman spectra were carried out by Jie Su at the Structural Composition Testing Center, School of Chemistry and Chemical Engineering, Shandong University.

Conflicts of Interest

We declare that we have no conflicts of interest.

References

  1. Ma, X.; Zhu, H.; Yu, L.; Li, X.; Ye, E.; Li, Z.; Loh, X.J.; Wang, S. Rare-earth-doped indium oxide nanosphere-based gas sensor for highly sensitive formaldehyde detection at a low temperature. Nanoscale 2023, 15, 1609–1618. [Google Scholar] [CrossRef]
  2. Gu, F.; Li, C.; Han, D.; Wang, Z. Manipulating the Defect Structure (VO) of In2O3 Nanoparticles for Enhancement of Formaldehyde Detection. ACS Appl. Mater. Interfaces 2018, 10, 933–942. [Google Scholar] [CrossRef] [PubMed]
  3. Bu, W.; Liu, N.; Zhang, Y.; Han, W.; Chuai, X.; Zhou, Z.; Hu, C.; Lu, G. Atomically dispersed Pt on MOF-derived In2O3 for chemiresistive formaldehyde gas sensing. Sens. Actuators: B. Chem. 2024, 404, 135260. [Google Scholar] [CrossRef]
  4. Gu, F.; Di, M.; Han, D.; Hong, S.; Wang, Z. Atomically Dispersed Au on In2O3 Nanosheets for Highly Sensitive and Selective Detection of Formaldehyde. ACS Sens. 2020, 5, 2611–2619. [Google Scholar] [CrossRef]
  5. Kong, D.L.; Niu, J.Y.; Hong, B.; Xu, J.C.; Han, Y.B.; Peng, X.L.; Ge, H.L.; Li, J.; Zeng, Y.X.; Wang, X.Q. Ag-nanoparticles-anchored mesoporous In2O3 nanowires for ultrahigh sensitive formaldehyde gas sensors. Mater. Sci. Eng. B 2023, 291, 116394. [Google Scholar] [CrossRef]
  6. Zhang, S.; Sun, S.; Huang, B.; Wang, N.; Li, X. UV-Enhanced Formaldehyde Sensor Using Hollow In2O3@TiO2 Double-Layer Nanospheres at Room Temperature. ACS Appl. Mater. Interfaces 2023, 15, 4329–4342. [Google Scholar] [CrossRef] [PubMed]
  7. Zhai, L.; Dai, X.; Zhu, G.; Rao, F.; Wang, S.; Yang, J.; Zhu, L.; Shi, X.; Huang, Y.; Jia, Y.; et al. High sensitivity and fast response sensor for formaldehyde based on In2O3/Sn2O3 heterojunction. Colloids Surf. A: Physicochem. Eng. Asp. 2023, 678, 132457. [Google Scholar] [CrossRef]
  8. Guo, L.; Liang, H.; Hu, H.; Shi, S.; Wang, C.; Lv, S.; Yang, H.; Li, H.; de Rooij, N.F.; Lee, Y.; et al. Large-Area and Visible-Light-Driven Heterojunctions of In2O3/Graphene Built for ppb-Level Formaldehyde Detection at Room Temperature. ACS Appl. Mater. Interfaces 2023, 15, 18205–18216. [Google Scholar] [CrossRef]
  9. Zi, B.; Chen, M.; Zhu, Q.; Lu, Q.; Xiao, B.; Deng, Z.; Xu, D.; Song, Z.; Zhao, J.; Zhang, Y.; et al. CuO@In2O3/ZnO Core-Shell Nanorods for Triethylamine Detection at Room Temperature. ACS Appl. Nano Mater. 2023, 6, 6963–6971. [Google Scholar] [CrossRef]
  10. Zhao, Q.; Zhuang, G.; Zhao, Y.; Yang, L.; Zhao, J. Y-doped In2O3 hollow nanocubes for improved triethylamine-sensing performance. New J. Chem. 2021, 45, 6773–6779. [Google Scholar] [CrossRef]
  11. Lv, Y.; Li, Y.; Zhou, R.; Pan, Y.; Yao, H.; Li, Z. N-Doped Graphene Quantum Dot-Decorated Three-Dimensional Ordered Macroporous In2O3 for NO2 Sensing at Low Temperatures. ACS Appl. Mater. Interfaces 2020, 12, 34245–34253. [Google Scholar] [CrossRef]
  12. Cheng, Y.; Cheng, L.; Ma, N.; Li, Z.; Tang, T.; Hu, X.; Liu, L.; Jannat, A.; Zhao, F.; Ou, J. Effect of Zn Concentration in Zinc-Doped 2D Layered Indium Oxides for Room-Temperature Optoelectronic Sensing of NO2. ACS Appl. Nano Mater. 2025, 8, 8354–8365. [Google Scholar] [CrossRef]
  13. Han, J.; Gu, G.; Gao, Y.; Yu, N.; Zhou, W.; Wang, Y.; Kong, D.; Gao, Y.; Lu, G. Prototype Alarm Integrating Pulse-Driven Nitrogen Dioxide Sensor Based on Holey Graphene Oxide/In2O3. ACS Sens. 2024, 9, 5425–5435. [Google Scholar] [CrossRef]
  14. Zhang, T.; Li, Y.; Xu, T.; Zhang, H.; Yuan, Z.; Wang, H.; Zhuo, K. Room Temperature Sensing Properties of In2O3-MXene Composites to NO2. ACS Appl. Electron. Mater. 2024, 6, 6994–7002. [Google Scholar] [CrossRef]
  15. Han, J.; Wang, Y.; Zhou, W.; Kong, D.; Gao, Y.; Gao, Y.; Lu, G. Graphene oxide-mediated polymorphic engineering of In2O3 for boosted NO2 gas sensing performance. Sens. Actuators: B. Chem. 2025, 422, 136613. [Google Scholar] [CrossRef]
  16. Yang, W.; Huo, Y.; Wang, T.; Liu, X.; Li, D.; Yu, H.; Dong, X.; Yang, Y. RGO@In2O3 based flexible gas sensor: Efficient monitoring of trace NO2 gas at room temperature. Sens. Actuators: B. Chem. 2025, 430, 137359. [Google Scholar] [CrossRef]
  17. Du, H.; Li, X.; Zhang, Z.; Li, Q.; Zhao, L.; Wang, J. Ultrasensitive NO2 sensor based on In2O3 nanocubes/SnS2 nanoflowers hetero composites. Sens. Actuators B. Chem. 2025, 444, 138277. [Google Scholar] [CrossRef]
  18. Cao, P.; Xu, X.; Jia, F.; Zeng, Y.; Liu, W.; Wang, C.; Han, S.; Fang, M.; Liu, X.; Zhu, D.; et al. Ultrasensitive room temperature chemiresistive NO2 gas sensing down to ppb levels using In2O3/rGO heterostructures. Appl. Surf. Sci. 2025, 688, 162424. [Google Scholar] [CrossRef]
  19. Wang, J.; Su, J.; Chen, H.; Zou, X.; Li, G. Oxygen vacancy-rich, Ru-doped In2O3 ultrathin nanosheets for efficient detection of xylene at low temperature. J. Mater. Chem. C. 2018, 6, 4156–4162. [Google Scholar] [CrossRef]
  20. Zhao, S.; Li, X.; Li, Y.; Fan, F.; Yao, H.; Li, Z. Au144 loaded hierarchical In2O3 nanospheres for effective detection of acetone in simulated exhalation. Sens. Actuators B Chem. 2023, 393, 134163. [Google Scholar] [CrossRef]
  21. Zhang, J.; Kong, M.; Li, K.; Chen, X.; Li, X.; Yue, L.; Yang, X.; Guan, R.; Zhang, W. Fabrication and ethanol sensing properties of hierarchical S-doped In2O3 networks. Sens. Actuators B Chem. 2023, 376 Pt B, 132965. [Google Scholar] [CrossRef]
  22. Wang, X.; Li, Y.; Sun, G.; Cao, J.; Wang, Y. Synthesis of Co-Doped In2O3 Hierarchical Porous Nanocubes for High-Performance Hydrogen Sulfide Sensors. Langmuir 2025, 41, 14185–14196. [Google Scholar] [CrossRef] [PubMed]
  23. Yang, X.; He, X.; Tang, B.; Zhong, L.; Zhang, W.; Chen, C.; He, T. Room Temperature Hydrogen Sensor of Mace-Like In2O3@ZnO Microtubules. ACS Appl. Electron. Mater. 2024, 6, 5885–5893. [Google Scholar] [CrossRef]
  24. Wang, Y.; Chen, C.; Xiao, G.; Chen, C.; He, X.; Zhou, J.; Huang, Z.; Le, J.; Zhou, X. Novel high performance room temperature hydrogen sensor-3D In2O3@rGO@PPy aerogel with dual enhancement of mechanical and gas sensitive properties. Int. J. Hydrogen Energy 2025, 154, 150170. [Google Scholar] [CrossRef]
  25. Han, B.; Wang, H.; Yang, W.; Wang, J.; Wei, X. Hierarchical Pt-decorated In2O3 microspheres with highly enhanced isoprene sensing properties. Ceram. Int. Part A 2021, 47, 9477–9485. [Google Scholar] [CrossRef]
  26. Min, S.; Kim, H.; Chang, S. Highly sensitive toluene sensor based on porous core-shell-structured In2O3-ZnO nanofibers under UV irradiation at room temperature. Phys. E Low-Dimens. Syst. Nanostruct. 2023, 154, 115806. [Google Scholar] [CrossRef]
  27. Rossi, A.; Fabbri, B.; Spagnoli, E.; Gaiardo, A.; Valt, M.; Ferroni, M.; Ardit, M.; Krik, S.; Pedrielli, A.; Vanzetti, L.; et al. Functionalization of Indium Oxide for Empowered Detection of CO2 over an Extra-Wide Range of Concentrations. ACS Appl. Mater. Interfaces 2023, 15, 33732–33743. [Google Scholar] [CrossRef] [PubMed]
  28. Wang, X.; Li, Y.; Jin, X.; Sun, G.; Cao, J.; Wang, Y. Effectively Improved CH4 Sensing Performance of In2O3 Porous Hollow Nanospheres by Doping with Cd. Langmuir 2024, 40, 24740–24749. [Google Scholar] [CrossRef]
  29. Zhao, Q.; Liu, Z.; Xu, Z.; Li, B.; Yang, S. r-GO/In2O3 heterostructures based gas sensor for efficient ppb-level n-butanol detection. J. Alloys Compd. 2024, 986, 174154. [Google Scholar] [CrossRef]
  30. Xu, X.; Zhang, C.; Yang, W.; Li, Y.; Li, B.; Haldorai, Y.; Jiang, Z.; Xie, W. Nanofiber-shaped Co3O4@In2O3 composite for high-performance enzymeless glucose sensing. Nanoscale 2025, 17, 6718. [Google Scholar] [CrossRef]
  31. Cheng, Y.; Portela, R.; Wang, P.; Liu, P.; Mao, Y.; Lim, K.H.; Zheng, J.; Yang, X.; Zhang, G.; Ding, L.; et al. Ultrasensitive In2O3-Based Nanoflakes for Lung Cancer Diagnosis and the Sensing Mechanism Investigated by Operando Spectroscopy. ACS Sens. 2024, 9, 6382–6389. [Google Scholar] [CrossRef]
  32. Shi, Z.; Yang, L.; Lu, Z.; Han, Q.; Wu, L.; Wang, L.; Xiong, Y.; Ye, J.; Zou, Z.; Zhou, Y. Comprehensive Insight into Indium Oxide-Based Catalysts for CO2 Hydrogenation: Thermal, Photo, and Photothermal Catalysis. Adv. Funct. Mater. 2024, 34, 2409904. [Google Scholar] [CrossRef]
  33. Dong, X.; Zhu, Z.; Chen, Z.; Sun, Z.; Qian, S.; Wang, Z.; Zhou, Y.; Nie, K.; Liu, S.; Li, Z.; et al. Boosting Solar Methanol Production over Hierarchical Carbon Nanocage-Supported In2O3−x via Photoenhanced Electron Buffering Effect. ACS Nano 2025, 19, 25403–25412. [Google Scholar] [CrossRef]
  34. Wissink, T.; Rollier, F.A.; Muravev, V.; Heinrichs, J.M.J.J.; van de Poll, R.C.J.; Zhu, J.; Anastasiadou, D.; Kosinov, N.; Figueiredo, M.C.; Hensen, E.J.M. Ce Promotion of In2O3 for Electrochemical Reduction of CO2 to Formate. ACS Catal. 2024, 14, 16589–16604. [Google Scholar] [CrossRef]
  35. Tang, J.; Pang, J.; Lv, X.; Wang, X. Photocatalytic CO2 Reduction with 100% CO Selectivity Using In2O3/CuO/g-C3N4 Ternary Composites. ACS Appl. Energy Mater. 2025, 8, 9683–9690. [Google Scholar] [CrossRef]
  36. Zhao, X.; Zhou, Y.; Pan, D.; Liang, Q.; Zhou, M.; Xu, S.; Li, Z.; Zhou, Y. Tailoring high-index-facet and oxygen defect of black In2O3−x/In2O3 as highly photothermal catalyst for boosting photocatalytic hydrogen evolution and contaminant degradation. J. Environ. Chem. Eng. 2023, 11, 109752. [Google Scholar] [CrossRef]
  37. He, Q.; Jin, Q.; Chen, C.; Wang, J.; Yuan, S.; Le, S.; Yang, F.; Yin, Y.; Du, F.; Xu, H.; et al. Ternary dual S-scheme In2O3/SnIn4S8/CdS heterojunctions for boosted light-to-hydrogen conversion. J. Colloid Interface Sci. Part A 2023, 650, 416–425. [Google Scholar] [CrossRef] [PubMed]
  38. Vu, M.; Quach, T.; Do, T. The construction of Ru-doped In2O3 hollow peanut-like structure for an enhanced photocatalytic nitrogen reduction under solar light irradiation. Sustain. Energy Fuels 2021, 5, 2528–2536. [Google Scholar] [CrossRef]
  39. Liu, J.; Yuan, W.; Zhu, M.; Hu, Z.; Wu, D.; Ji, X.; Zhang, D.; Pu, X. In2S3/In2O3 Nanocomposite In Situ Forming an S-Scheme Heterojunction for the Photocatalytic Degradation of Tetracycline under Visible Light. ACS Appl. Nano Mater. 2024, 7, 20339–20348. [Google Scholar] [CrossRef]
  40. Su, T.; Chen, Z.; Luo, X.; Xie, X.; Qin, Z.; Ji, H. Preparation of Fe-doped In2S3/In2O3 Composite for Photocatalytic Degradation of Tetracycline. ACS Chem. Health Saf. 2024, 31, 490–502. [Google Scholar] [CrossRef]
  41. Jin, J.; Huang, J.; Liu, X.; Zeng, C.; Dai, C.; Jia, Y. Z-Scheme Ag2S−Ag−In2O3 Heterostructure with Efficient Antibiotics Removal under Natural Sunlight. Langmuir 2024, 40, 21842–21854. [Google Scholar] [CrossRef]
  42. Zhang, Y.; Song, Y.; Xu, J.; Ge, X.; Wu, X.; Lan, Y.; Zhao, Y.; Yan, D. Fabrication of Sn-doped In2O3 nanoparticles anchored on g-C3N4 nanosheets for enhanced degradation of Rhodamine B. Solid State Sci. 2025, 163, 107915. [Google Scholar] [CrossRef]
  43. Alsaif, M.M.Y.A.; Kuriakose, S.; Walia, S.; Syed, N.; Jannat, A.; Zhang, B.Y.; Haque, F.; Mohiuddin, M.; Alkathiri, T.; Pillai, N.; et al. 2D SnO/In2O3 van der Waals Heterostructure Photodetector Based on Printed Oxide Skin of Liquid Metals. Adv. Mater. Interfaces 2019, 6, 1900007. [Google Scholar] [CrossRef]
  44. Zhang, M.; Yu, H.; Li, H.; Jiang, Y.; Qu, L.; Wang, Y.; Gao, F.; Feng, W. Ultrathin In2O3 Nanosheets toward High Responsivity and Rejection Ratio Visible-Blind UV Photodetection. Small 2022, 19, 2205623. [Google Scholar] [CrossRef]
  45. Veeralingam, S.; Badhulika, S. Enhanced carrier separation assisted high-performance piezo-phototronic self-powered photodetector based on core-shell ZnSnO3 @In2O3 heterojunction. Nano Energy 2022, 98, 107354. [Google Scholar] [CrossRef]
  46. Wang, X.; Zhao, H.; Leea, B.; Kim, S. Improved performance and bias stability in TFTs with solution-processed graphene oxide-doped In2O3 active layers treated under deep UV irradiation. J. Mater. Chem. C. 2025, 13, 15721–15728. [Google Scholar] [CrossRef]
  47. Tarsoly, G.; Zhao, H.; Wang, X.; Lee, J.; Kim, S. Optimized responsivity of a phototransistor using graphene oxide-doped solution-processed indium oxide active layer toward neuromorphic Applications. J. Mater. Chem. C. 2024, 12, 12090. [Google Scholar] [CrossRef]
  48. Lee, J.; Tarsoly, G.; Kim, S. Graphene Oxide-Doped Indium Oxide Buffer Film Sandwiched between Titanium Oxide Layers for the Development of Photosensitive Resistive Memory Devices. ACS Appl. Mater. Interfaces 2024, 16, 64988–64994. [Google Scholar] [CrossRef] [PubMed]
  49. Rafeeq, M.; Ahmad, S.; Sami, A.; Khan, K.Z.; Haidar, Z.; Ahmed, F.; Yasmeen, G.; Ahmed, S.; Bahajjaj, A.A.A. Facile hydrothermal fabrication of In2O3/Fe2O3 as potential electrode material for supercapacitor. Electrochim. Acta 2025, 524, 145963. [Google Scholar] [CrossRef]
  50. Wu, Z.; Zhong, Y.; Wang, Z.; Li, L.; Liu, X. PdPbAg alloy NPs immobilized on reduced graphene oxide/In2O3 composites as highly active electrocatalysts for direct ethylene glycol fuel cells. RSC Adv. 2022, 12, 19929–19935. [Google Scholar] [CrossRef]
  51. Lei, P.; Zhou, X.; Wu, X.; Fu, H.; Li, H.; Huang, H. Biomimetic construction of oxygen vacancy-rich In2O3/In2S3@C heterostructures with built-in electric field for boosting bidirectional regulation of polysulfides in lithium-sulfur batteries. Chem. Eng. J. 2025, 516, 164100. [Google Scholar] [CrossRef]
  52. Li, J.; Li, W.; Tian, Y.; Wang, C. Integrated design of polysulfide shuttling and lithium dendrite suppressing framework: In2O3-In2S3 embedded carbon cloth for lithium-sulfur full batteries. Chem. Eng. J. 2025, 509, 161241. [Google Scholar] [CrossRef]
  53. Tong, X.; Song, Y.; Zhang, M.; Chen, Y.; Liu, Y.; Chen, J.; Wang, W.; Zhou, C.; Liu, F.; Meng, J. Carbon-Supported In2O3 Cathode with a Solution-to-Solid Conversion Chemistry Enables Fast-Charging and Durable Aluminum Battery. ACS Appl. Energy Mater. 2025, 8, 3553–3562. [Google Scholar] [CrossRef]
  54. Ramanathan, R.; Zinigrad, M.; Arjunan, K.; Ravichandran, K.; Barshilia, H.C.; Mallik, R.C. Facile surface modification process of Sn-doped In2O3 electron transport layer for enhanced perovskite solar cell performance. Sol. Energy Mater. Sol. Cells 2025, 284, 113481. [Google Scholar] [CrossRef]
  55. Ahmad, A.; Hussain, M.; Zhou, Z.; Liu, R.; Lin, Y.; Nan, C. Thermoelectric Performance Enhancement of Vanadium Doped n-Type In2O3 Ceramics via Carrier Engineering and Phonon Suppression. ACS Appl. Energy Mater. 2020, 3, 1552–1558. [Google Scholar] [CrossRef]
  56. Nielsen, I.G.; Sommer, S.; Iversen, B.B. Phase control for indium oxide nanoparticles. Nanoscale 2021, 13, 4038–4050. [Google Scholar] [CrossRef]
  57. Shimizu, M.; Shugo, M.; Mori, S.; Hijikata, Y.; Aikawa, S. The Influence of Oxygen-Related Defects on the Formation of In2O3-Based Low-Fluorescence Transparent Conducting Film. Phys. Status Solidi (A) 2023, 220, 2200896. [Google Scholar] [CrossRef]
  58. Arooj, S.; Xu, T.; Hou, X.; Wang, Y.; Tong, J.; Chu, R.; Liu, B. Green emission of indium oxide via hydrogen treatment. RSC Adv. 2018, 8, 11828–11833. [Google Scholar] [CrossRef] [PubMed]
  59. Hou, R.; Xiao, J.; Wu, Q.; Zhang, T.; Wang, Q. Boosting oxygen vacancies by modulating the morphology of Au decorated In2O3 with enhanced CO2 hydrogenation activity to CH3OH. J. Environ. Sci. 2024, 140, 91–102. [Google Scholar] [CrossRef]
  60. Xu, Q.; Yin, X.; Dong, M.; Feng, S.; Sun, H. Oxygen Vacancy-Induced Ferromagnetism and Resistive-Magnetization Switching Characteristics in In2O3 Films. J. Phys. Chem. C. 2023, 127, 10366–10374. [Google Scholar] [CrossRef]
  61. Sun, Z.; Shih, L.; Tseng, W.J. Facile preparation of In2O3-In2S3 core-shell composites for the enhanced photoelectric activity. Int. J. Appl. Ceram. Technol. 2024, 21, 133–141. [Google Scholar] [CrossRef]
  62. Zhao, Z.; Wang, P.; Song, C.; Zhang, T.; Zhan, S.; Li, Y. Enhanced Interfacial Electron Transfer by Asymmetric Cu-Ov-In Sites on In2O3 for Efficient Peroxymonosulfate Activation. Angew. Chem. 2023, 135, e202216403. [Google Scholar] [CrossRef]
  63. Kim, H.; Jeong, H.; Kim, T.; Chung, J.; Kang, Y.C.; Lee, J. Enhanced Ethanol Sensing Characteristics of In2O3-Decorated NiO Hollow Nanostructures via Modulation of Hole Accumulation Layers. ACS Appl. Mater. Interfaces 2014, 6, 18197–18204. [Google Scholar] [CrossRef]
  64. Wang, R.; Schultz, T.; Papadogianni, A.; Longhi, E.; Gatsios, C.; Zu, F.; Zhai, T.; Barlow, S.; Marder, S.R.; Bierwagen, O.; et al. Tuning the Surface Electron Accumulation Layer of In2O3 by Adsorption of Molecular Electron Donors and Acceptors. Small 2023, 19, 2300730. [Google Scholar] [CrossRef]
  65. Zhu, Y.; Ding, S.; Wang, X.; Zhang, R.; Feng, X.; Sun, X.; Xiao, G.; Zhu, Y. Interfacial Electronic Interaction in In2O3/Poly(3,4-ethylenedioxythiophene)-Modified Carbon Heterostructures for Enhanced Electroreduction of CO2 to Formate. ACS Appl. Mater. Interfaces 2023, 15, 33633–33642. [Google Scholar] [CrossRef]
  66. Yang, X.; Yu, W.; Wang, W.; Wang, D.; Wang, Q.; Huo, X. Size modulation of plasmonic In2O3 nanocube optimized photocatalytic H2 evolution over stack g-C3N4-In2O3 heterojunction. Int. J. Hydrogen Energy 2023, 48, 35599–35609. [Google Scholar] [CrossRef]
  67. Fang, H.; Hegde, M.; Yin, P.; Radovanovic, P.V. Tuning Plasmon Resonance of In2O3 Nanocrystals throughout the Mid-Infrared Region by Competition between Electron Activation and Trapping. Chem. Mater. 2017, 29, 4970–4979. [Google Scholar] [CrossRef]
  68. Yang, Y.; Shen, C.; Sun, K.; Mei, D.; Liu, C. Enhanced Surface Charge Localization Over Nitrogen-Doped In2O3 for CO2 Hydrogenation to Methanol with Improved Stability. ACS Catal. 2023, 13, 6154–6168. [Google Scholar] [CrossRef]
  69. Isakov, I.; Faber, H.; Mottram, A.D.; Das, S.; Grell, M.; Regoutz, A.; Kilmurray, R.; McLachlan, M.A.; Payne, D.J.; Anthopoulos, T.D. Quantum Confinement and Thickness-Dependent Electron Transport in Solution-Processed In2O3 Transistors. Adv. Electron. Mater. 2020, 6, 2000682. [Google Scholar] [CrossRef]
  70. Liang, S.; Jin, D.; Fu, Y.; Lin, Q.; Zhang, R.; Wang, X. Interfacial elaborating In2O3-decorated ZnO/reduced graphene oxide/ZnS heterostructure with robust internal electric field for efficient solar-driven hydrogen evolution. J. Colloid Interface Sci. 2023, 635, 128–137. [Google Scholar] [CrossRef] [PubMed]
  71. Yin, P.; Hegde, M.; Tan, Y.; Chen, S.; Garnet, N.; Radovanovic, P.V. Controlling the Mechanism of Excitonic Splitting in In2O3 Nanocrystals by Carrier Delocalization. ACS Nano 2018, 12, 11211–11218. [Google Scholar] [CrossRef]
  72. Nath, A.; Sarkar, M.B. An in-depth analysis on the switching response and impedance curves of n-si/In2O3 NW/Ag NPs/In based devices by a double-step glancing angle deposition technique. Phys. B: Condens. Matter 2023, 660, 414886. [Google Scholar] [CrossRef]
  73. Bhuvaneswari, S.; Seetha, M.; Chandrasekaran, J.; Marnadu, R.; Masuda, Y.; Aldossary, O.M.; Ubaidullah, M. Fabrication and characterization of p-Si/n-In2O3 and p-Si/n-ITO junction diodes for optoelectronic device applications. Surf. Interfaces 2021, 23, 100992. [Google Scholar] [CrossRef]
  74. Ma, X.; Li, C.; Gao, M.; Zhang, X.; Wang, Y.; Li, G. Interface Optimization of Metal Quantum Dots/Polymer Nanocomposites and Their Properties: Studies of Multi-Functional Organic/Inorganic Hybrid. Materials 2023, 16, 150. [Google Scholar] [CrossRef] [PubMed]
  75. Wang, Y.; Chen, Y.; Bui, H.T.; Wolf, C.; Haze, M.; Mier, C.; Kim, J.; Choi, D.; Lutz, C.P.; Bae, Y.; et al. An atomic-scale multi-qubit platform. Science 2023, 382, 87–92. [Google Scholar] [CrossRef] [PubMed]
  76. Zheng, J.; Ma, X.; He, X.; Gao, M.; Li, G. Praparation, characterizations, and its potential applications of PANi/graphene oxide nanocomposite. Procedia Eng. 2012, 27, 1478–1487. [Google Scholar] [CrossRef]
  77. Ma, X.; Zhang, X.; Gao, M.; Hu, R.; Wang, Y.; Li, G. In2S3/C3N4 Nanocomposite and Its Photoelectric Properties in the Broadband Light Spectrum Range. Coatings 2025, 15, 718. [Google Scholar] [CrossRef]
  78. Ma, X.; Zhang, X.; Gao, M.; Hu, R.; Wang, Y.; Li, G. The Interface Interaction of C3N4/Bi2S3 Promoted the Separation of Excitons and the Extraction of Free Photogenerated Carriers in the Broadband Light Spectrum Range. Inorganics 2025, 13, 122. [Google Scholar] [CrossRef]
  79. Wang, Z.; Shi, X.; Peng, H. Alternating current electroluminescent fibers for textile displays. Natl. Sci. Rev. 2023, 10, nwac113. [Google Scholar] [CrossRef]
  80. Wang, L.; Zhang, Y.; Bruce, P.G. Batteries for wearables. Natl. Sci. Rev. 2023, 10, nwac062. [Google Scholar] [CrossRef]
  81. Shoyiga, H.O.; Martincigh, B.S.; Nyamori, V.O. Recyclable and biodegradable smart electronic circuits on flexible substrates. Polym. Plast. Technol. Mater. 2023, 62, 2159–2181. [Google Scholar] [CrossRef]
Coatings 15 01448 sch001
Scheme 1. The structure of the electrodes in the study.
Scheme 1. The structure of the electrodes in the study.
Coatings 15 01448 sch001
Coatings 15 01448 g001
Figure 1. The representative SEM (scanning electron microscope) image of In2O3-r-G (10)-PVA (10 mL) ((A) the magnification is 11,750×; (B) the magnification is 15,080×; (C) the magnification is 29,950×).
Figure 1. The representative SEM (scanning electron microscope) image of In2O3-r-G (10)-PVA (10 mL) ((A) the magnification is 11,750×; (B) the magnification is 15,080×; (C) the magnification is 29,950×).
Coatings 15 01448 g001
Coatings 15 01448 g002
Figure 2. The XRD results of the resulting nanocomposites ((A) In2O3-r-G (10) and In2O3-r-G (20); (B) In2O3-r-G (10) and In2O3-r-G (10)-PVA (10 mL)).
Figure 2. The XRD results of the resulting nanocomposites ((A) In2O3-r-G (10) and In2O3-r-G (20); (B) In2O3-r-G (10) and In2O3-r-G (10)-PVA (10 mL)).
Coatings 15 01448 g002
Coatings 15 01448 g003
Figure 3. Raman spectra of In2O3-r-G(10)-PVA (10 mL).
Figure 3. Raman spectra of In2O3-r-G(10)-PVA (10 mL).
Coatings 15 01448 g003
Coatings 15 01448 g004
Figure 4. The UV–Vis-NIR absorbance curve of In2O3-rG-PVA nanocomposite ((A) UV–Vis of In2O3-r-G (10 and 20 mL); (B) UV–Vis of In2O3-r-G (10 and 20 mL)-PVA (10 mL); (C) UV–Vis of In2O3-r-G(10)-PVA (0 and 10 mL); (D) UV–Vis of In2O3-r-G (20)-PVA (0 and 10 mL)).
Figure 4. The UV–Vis-NIR absorbance curve of In2O3-rG-PVA nanocomposite ((A) UV–Vis of In2O3-r-G (10 and 20 mL); (B) UV–Vis of In2O3-r-G (10 and 20 mL)-PVA (10 mL); (C) UV–Vis of In2O3-r-G(10)-PVA (0 and 10 mL); (D) UV–Vis of In2O3-r-G (20)-PVA (0 and 10 mL)).
Coatings 15 01448 g004
Coatings 15 01448 g005
Figure 5. The comparatively transient-state photocurrent responses of In2O3-r-G-PVA nanocomposite to the weak visible light (25 W) ((A) In2O3/r-G (10 mL) to the visible light; (B) In2O3/r-G (10 mL)/PVA (10 mL) to the visible light; (C) In2O3/r-G (20 mL) to the visible light; (D) In2O3/r-G (20 mL)/PVA (10 mL) to the visible light) (with Ag fibres as electrodes and paper as substrate).
Figure 5. The comparatively transient-state photocurrent responses of In2O3-r-G-PVA nanocomposite to the weak visible light (25 W) ((A) In2O3/r-G (10 mL) to the visible light; (B) In2O3/r-G (10 mL)/PVA (10 mL) to the visible light; (C) In2O3/r-G (20 mL) to the visible light; (D) In2O3/r-G (20 mL)/PVA (10 mL) to the visible light) (with Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g005
Coatings 15 01448 g006
Figure 6. The comparatively transient state photocurrent responses of the In2O3-r-G-PVA to 100 mW of 650 nm ((A) In2O3/r-G (10 mL) to 100 mW of 650 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 100 mW of 650 nm light source) (Ag fibres as electrodes and paper as substrate).
Figure 6. The comparatively transient state photocurrent responses of the In2O3-r-G-PVA to 100 mW of 650 nm ((A) In2O3/r-G (10 mL) to 100 mW of 650 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 100 mW of 650 nm light source) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g006
Coatings 15 01448 g007
Figure 7. The comparatively transient state photocurrent responses of the In2O3-r-G-PVA to 200 mW of 808 nm ((A) In2O3/r-G (10 mL) to 200 mW of 808 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 200 mW of 808 nm light source; (C) In2O3/r-G (20 mL) to 200 mW of 808 nm light source; (D) In2O3/r-G(20 mL)/PVA(10 mL) to 200 mW of 808 nm light source) (Ag fibres as electrodes and paper as substrate).
Figure 7. The comparatively transient state photocurrent responses of the In2O3-r-G-PVA to 200 mW of 808 nm ((A) In2O3/r-G (10 mL) to 200 mW of 808 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 200 mW of 808 nm light source; (C) In2O3/r-G (20 mL) to 200 mW of 808 nm light source; (D) In2O3/r-G(20 mL)/PVA(10 mL) to 200 mW of 808 nm light source) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g007
Coatings 15 01448 g008
Figure 8. The comparatively transient state photocurrent responses of the In2O3/r-G and the In2O3-r-G-PVA to 200 mW of 980 nm ((A) In2O3/r-G (10 mL) to 100 mW of 980 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 200 mW of 980 nm light source) (Ag fibres as electrodes and paper as substrate).
Figure 8. The comparatively transient state photocurrent responses of the In2O3/r-G and the In2O3-r-G-PVA to 200 mW of 980 nm ((A) In2O3/r-G (10 mL) to 100 mW of 980 nm light source; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 200 mW of 980 nm light source) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g008
Coatings 15 01448 g009
Figure 9. The dependence of the photoelectric signal on the incident light power ((A) In2O3/r-G (10 mL)/PVA (10 mL) to 650 nm light sources of 100, 50, and 20 mW; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 980 nm light sources of 200, 100, and 50 mW) (Ag fibres as electrodes and paper as substrate).
Figure 9. The dependence of the photoelectric signal on the incident light power ((A) In2O3/r-G (10 mL)/PVA (10 mL) to 650 nm light sources of 100, 50, and 20 mW; (B) In2O3/r-G (10 mL)/PVA (10 mL) to 980 nm light sources of 200, 100, and 50 mW) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g009
Coatings 15 01448 g010
Figure 10. The representative cyclic photocurrent responses of In2O3/r-G (10 and 20 mL)/PVA (10 mL) to 980 nm light sources of 200 mW ((A,B) In2O3/r-G (10 mL)/PVA (10 mL); (C,D) In2O3/r-G (20 mL)/PVA (10 mL)) (Ag fibres as electrodes and paper as substrate).
Figure 10. The representative cyclic photocurrent responses of In2O3/r-G (10 and 20 mL)/PVA (10 mL) to 980 nm light sources of 200 mW ((A,B) In2O3/r-G (10 mL)/PVA (10 mL); (C,D) In2O3/r-G (20 mL)/PVA (10 mL)) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g010
Coatings 15 01448 g011
Figure 11. The In2O3/r-G(10 and 20 mL)/PVA (10 mL) on silk fibre to 650 nm of light resource at 100 mW and 808 nm of light source at 200 mW ((A) In2O3/r-G (10 mL)/PVA(10 mL) on silk fibre to 100 mW of 650 nm light source; (B) In2O3/r-G (20 mL)/PVA(10 mL) on silk fibre to 100 mW of 650 nm light source; (C): In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 200 mW of 808 nm light source; (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 200 mW of 808 nm light source) (Ag fibres as electrodes and paper as substrate).
Figure 11. The In2O3/r-G(10 and 20 mL)/PVA (10 mL) on silk fibre to 650 nm of light resource at 100 mW and 808 nm of light source at 200 mW ((A) In2O3/r-G (10 mL)/PVA(10 mL) on silk fibre to 100 mW of 650 nm light source; (B) In2O3/r-G (20 mL)/PVA(10 mL) on silk fibre to 100 mW of 650 nm light source; (C): In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 200 mW of 808 nm light source; (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 200 mW of 808 nm light source) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g011
Coatings 15 01448 g012
Figure 12. The photocurrent responses of In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 980 nm light source of 200 mW and the visible light ((A) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 200 mW of 980 nm light source; (B) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 200 mW of 980 nm light source; (C) In2O3/r-G (10 mL)/PVA(10 mL) on silk fibre to the visible light (25 W); (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to the visible light (25 W)) (Ag fibres as electrodes and paper as substrate).
Figure 12. The photocurrent responses of In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 980 nm light source of 200 mW and the visible light ((A) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 200 mW of 980 nm light source; (B) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 200 mW of 980 nm light source; (C) In2O3/r-G (10 mL)/PVA(10 mL) on silk fibre to the visible light (25 W); (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to the visible light (25 W)) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g012
Coatings 15 01448 g013
Figure 13. The electrical response of In2O3/r-G (10 and 20 mL)/PVA(10 mL) on silk fibre to the force applied ((A) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 50 g compression force; (B) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 100 g compression force; (C) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 100 g compression force; (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 100 g compression force) (Ag fibres as electrodes and paper as substrate).
Figure 13. The electrical response of In2O3/r-G (10 and 20 mL)/PVA(10 mL) on silk fibre to the force applied ((A) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 50 g compression force; (B) In2O3/r-G (10 mL)/PVA (10 mL) on silk fibre to 100 g compression force; (C) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 100 g compression force; (D) In2O3/r-G (20 mL)/PVA (10 mL) on silk fibre to 100 g compression force) (Ag fibres as electrodes and paper as substrate).
Coatings 15 01448 g013
Coatings 15 01448 g014
Figure 14. The photocurrent responses of In2O3/r-G (10 and 20 mL) to 808 nm (200 mW) and 980 nm (100 mW) light sources ((A,B) In2O3/r-G (10 mL) to 808 nm (200 mW) and 980 nm (100 mW); (C,D) In2O3/r-G (20 mL) to 808 nm (200 mW) and 980 nm (100 mW)) (Au gap electrodes of the PET film).
Figure 14. The photocurrent responses of In2O3/r-G (10 and 20 mL) to 808 nm (200 mW) and 980 nm (100 mW) light sources ((A,B) In2O3/r-G (10 mL) to 808 nm (200 mW) and 980 nm (100 mW); (C,D) In2O3/r-G (20 mL) to 808 nm (200 mW) and 980 nm (100 mW)) (Au gap electrodes of the PET film).
Coatings 15 01448 g014
Coatings 15 01448 g015
Figure 15. The photocurrent responses of In2O3/r-G (10 and 20 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW) light sources ((A,B) In2O3/r-G (10 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW); (C,D) In2O3/r-G (20 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW)) (Au gap electrodes of the PET film).
Figure 15. The photocurrent responses of In2O3/r-G (10 and 20 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW) light sources ((A,B) In2O3/r-G (10 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW); (C,D) In2O3/r-G (20 mL) treated with dendrimers (G3) to 808 nm (200 mW) and 980 nm (100 mW)) (Au gap electrodes of the PET film).
Coatings 15 01448 g015
Coatings 15 01448 g016
Figure 16. The photocurrent responses of In2O3/r-G (20 mL) and In2O3/r-G (20 mL) treated with dendrimers (G3) to 1064 nm (20mW) light source ((A) In2O3/r-G (20 mL); (B) In2O3/r-G (20 mL) treated with dendrimers (G3)) (Au gap electrodes of the PET film).
Figure 16. The photocurrent responses of In2O3/r-G (20 mL) and In2O3/r-G (20 mL) treated with dendrimers (G3) to 1064 nm (20mW) light source ((A) In2O3/r-G (20 mL); (B) In2O3/r-G (20 mL) treated with dendrimers (G3)) (Au gap electrodes of the PET film).
Coatings 15 01448 g016
Coatings 15 01448 g017
Figure 17. The photocurrent responses of In2O3/r-G (10 mL) treated with dendrimers (G3) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Figure 17. The photocurrent responses of In2O3/r-G (10 mL) treated with dendrimers (G3) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Coatings 15 01448 g017
Coatings 15 01448 g018
Figure 18. The photocurrent responses of In2O3/r-G (20 mL) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Figure 18. The photocurrent responses of In2O3/r-G (20 mL) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Coatings 15 01448 g018
Coatings 15 01448 g019
Figure 19. The photocurrent responses of In2O3/r-G (20 mL) treated with dendrimers (G3) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Figure 19. The photocurrent responses of In2O3/r-G (20 mL) treated with dendrimers (G3) to 980 nm (100, 50, and 5 mW) light sources ((A,B) 0 V bias; (C,D) 1 V bias) ((B,D) Localised enlargement to 5 mW of 980 nm light source) (Au gap electrodes of the PET film).
Coatings 15 01448 g019
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Ma, X.; Zhang, X.; Gao, M.; Hu, R.; Wang, Y.; Li, G. Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum. Coatings 2025, 15, 1448. https://doi.org/10.3390/coatings15121448

AMA Style

Ma X, Zhang X, Gao M, Hu R, Wang Y, Li G. Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum. Coatings. 2025; 15(12):1448. https://doi.org/10.3390/coatings15121448

Chicago/Turabian Style

Ma, Xingfa, Xintao Zhang, Mingjun Gao, Ruifen Hu, You Wang, and Guang Li. 2025. "Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum" Coatings 15, no. 12: 1448. https://doi.org/10.3390/coatings15121448

APA Style

Ma, X., Zhang, X., Gao, M., Hu, R., Wang, Y., & Li, G. (2025). Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum. Coatings, 15(12), 1448. https://doi.org/10.3390/coatings15121448

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop