GaS powder, GaS thin film electrodes and their preparation methods, photodetectors

Abstract

This disclosure provides GaS powder, GaS thin-film electrodes and their preparation methods, and a photodetector, relating to the field of semiconductor materials technology. The method for preparing the GaS powder includes: mixing choline chloride and urea, followed by stirring and vacuum cooling to remove water, to obtain a first intermediate product; adding GaCl3 to the first intermediate product in multiple batches under a protective atmosphere to obtain a second intermediate product; adding thiourea to the second intermediate product in multiple batches to obtain a third intermediate product; adding NaBH4 to the third intermediate product to obtain a fourth intermediate product; annealing the fourth intermediate product; washing it with citric acid after annealing; and centrifuging it to obtain GaS powder. This disclosure can improve the crystallinity of GaS materials.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor materials technology, and more specifically, to a GaS powder, a GaS thin film electrode and its preparation method, and a photodetector. Background Technology

[0002] Gallium sulfide (GaS) is a typical group III-VI layered two-dimensional semiconductor material with a direct band gap of about 2.5 eV (monolayer) and an indirect band gap of about 2.3 eV (bulk phase). It exhibits strong light absorption in the ultraviolet to near-infrared band and demonstrates good carrier mobility, photoelectric response and environmental stability. Therefore, it has broad application prospects in photodetectors, field-effect transistors, photocatalysis and photoelectrochemical cells.

[0003] Currently, the synthesis of GaS materials generally suffers from low crystallinity and difficulty in achieving large-area, uniform, and controllable growth. Providing an environmentally friendly and simple-to-operate GaS material synthesis process is of great significance for promoting its application in optoelectronic devices, especially flexible optoelectronic devices.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a GaS powder, a GaS thin film electrode and its preparation method, and a photodetector, thereby overcoming, at least to some extent, the problem of low crystallinity in GaS material synthesis.

[0006] According to a first aspect of this disclosure, a method for preparing GaS powder is provided, comprising: mixing choline chloride with urea, and after stirring and vacuum cooling to remove water, obtaining a first intermediate product; adding GaCl3 to the first intermediate product in multiple portions under a protective atmosphere to obtain a second intermediate product; adding thiourea to the second intermediate product in multiple portions to obtain a third intermediate product; adding NaBH4 to the third intermediate product to obtain a fourth intermediate product; annealing the fourth intermediate product; washing it with citric acid after annealing; and centrifuging it to obtain GaS powder.

[0007] Optionally, choline chloride is mixed with urea, and after stirring and vacuum cooling to remove water, a first intermediate product is obtained, comprising: mixing 7-10g of choline chloride with 10-15g of urea, stirring at 80-90℃ for 30-60min to obtain a molten salt product; and subjecting the molten salt product to vacuum cooling to remove water for 1-2h to obtain the first intermediate product.

[0008] Optionally, GaCl3 is added to the first intermediate product in multiple batches to obtain the second intermediate product, including: adding GaCl3 to the first intermediate product in 3 to 5 batches to obtain the second intermediate product; wherein the total amount of GaCl3 added is 1 to 1.75 g, the interval between each addition is 5 to 10 min, and the process of obtaining the second intermediate product is carried out by stirring at 80 to 90 °C and 300 to 500 rpm.

[0009] Optionally, thiourea is added to the second intermediate in multiple portions to obtain the third intermediate, including: adding thiourea to the second intermediate in 2 to 5 portions to obtain the third intermediate; wherein the total amount of thiourea added is 1 to 2 g, and the process of obtaining the third intermediate is carried out by stirring at 80 to 90°C.

[0010] Optionally, the amount of NaBH4 added to the third intermediate is 0.1~0.3g.

[0011] Optionally, the fourth intermediate product is annealed, and after annealing, it is cleaned with citric acid and centrifuged to obtain GaS powder. The process includes: placing the fourth intermediate product in a vacuum tube furnace at 180~300℃ for 2~5h, with a heating rate of 2~5℃ / min, to perform annealing; after annealing, it is cleaned with 0.01~0.05M citric acid and centrifuged to obtain GaS powder.

[0012] According to a second aspect of this disclosure, a GaS powder is provided, prepared using any of the above-described methods for preparing GaS powder.

[0013] According to a third aspect of this disclosure, a method for preparing a GaS thin film electrode is provided, comprising: dispersing GaS powder in an alcohol solvent and sonicating it to obtain a dispersion; wherein the GaS powder is prepared using any of the above-described methods for preparing GaS powder; spraying the dispersion onto a substrate surface to form a precursor electrode; adding (NH4)2S solution dropwise onto the surface of the precursor electrode, and then annealing it after vacuum sealing to obtain the GaS thin film electrode.

[0014] According to a fourth aspect of this disclosure, a GaS thin film electrode is provided, which is prepared using the above-described method for preparing a GaS thin film electrode.

[0015] According to a fifth aspect of this disclosure, a photodetector is provided, comprising a GaS thin film electrode, the GaS thin film electrode being fabricated using the above-described method for fabricating GaS thin film electrodes.

[0016] In the exemplary embodiments of this disclosure, GaS powder is prepared using a solution-based method, resulting in excellent crystallinity, simple operation, environmental friendliness, and low cost. Furthermore, by selecting appropriate raw materials and controlling process steps, such as adding thiourea in multiple stages, this disclosure can further improve the crystallinity of GaS, which will help promote the application of GaS materials in fields such as photodetectors.

[0017] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0019] Figure 1 A schematic diagram illustrating the mechanism of preparing GaS materials according to embodiments of the present disclosure is shown.

[0020] Figure 2 A flowchart illustrating a method for preparing GaS powder according to an exemplary embodiment of the present disclosure is shown.

[0021] Figure 3 A flowchart illustrating a method for fabricating a GaS thin-film electrode according to an exemplary embodiment of the present disclosure is shown.

[0022] Figure 4 The diagram illustrates the XRD (X-Ray Diffraction) patterns of GaS materials at different annealing temperatures according to embodiments of the present disclosure.

[0023] Figure 5 The diagram illustrates the diffuse reflection of ultraviolet-visible light from a GaS material according to an embodiment of the present disclosure.

[0024] Figure 6 The diagram illustrates SEM (Scanning Electron Microscope) images of the GaS thin film electrode surface according to an embodiment of this disclosure. Figure A shows the microstructure at a 10 μm scale, and Figure B shows the microstructure at a 5 μm scale.

[0025] Figure 7 The photoelectric response curves of GaS materials at different annealing temperatures according to embodiments of the present disclosure are illustrated schematically.

[0026] Figure 8The IV test curve of GaS material according to an embodiment of this disclosure is illustrated schematically.

[0027] Figure 9 The light response curves of the GaS material according to embodiments of the present disclosure at different optical powers are illustrated schematically.

[0028] Figure 10 A schematic diagram of a photodetector including a GaS thin-film electrode according to an embodiment of the present disclosure is shown.

[0029] Figure 11 A schematic diagram is shown illustrating the response speed of the photodetector of Embodiment 1 of this disclosure to a 380nm laser.

[0030] Figure 12 A schematic diagram of the response speed of the photodetector of Embodiment 2 of this disclosure to a 380nm laser is shown.

[0031] Figure 13 A schematic diagram is shown illustrating the response speed of the photodetector of Embodiment 3 of this disclosure to a 380nm laser. Detailed Implementation

[0032] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of these specific details omitted, or other methods, processes, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0033] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. The flowcharts shown in the drawings are merely exemplary illustrations and do not necessarily include all steps. For example, some steps may be broken down, while others may be combined or partially combined; therefore, the actual order of execution may change depending on the actual situation. Additionally, all terms such as "first," "second," "third," and "fourth" below are for distinguishing purposes only and should not be construed as limiting the content of this disclosure.

[0034] Currently, the main methods for preparing GaS include mechanical exfoliation, chemical vapor deposition (CVD), and physical vapor transport (PVT). Among these, CVD is widely used due to its ability to controllably prepare large-area thin films. However, it typically requires temperatures above 900°C, resulting in high energy consumption, high equipment costs, and difficulty in meeting the low-temperature requirements of flexible substrates or downstream integrated circuit processes, severely limiting its application in flexible electronics and low-temperature devices.

[0035] In contrast, solution methods offer advantages such as low cost, simple processing, and ease of large-area film deposition, making them a promising alternative. However, GaS thin films prepared using traditional solution methods generally suffer from low crystallinity, small grain size, poor film uniformity, and organic residues, resulting in low carrier mobility, high dark current, and slow response speed, severely impacting the stability of their optoelectronic performance and the reproducibility of devices. Achieving controllable growth of highly crystalline, large-area uniform GaS thin films at lower temperatures (e.g., below 300°C) remains a significant technical challenge. Therefore, developing a new method for efficiently preparing highly crystalline, uniform GaS nanomaterials or thin films at relatively low temperatures, overcoming the dual bottlenecks of poor compatibility of existing high-temperature preparation methods and low crystallinity of traditional low-temperature solution methods, and developing an environmentally friendly, easy-to-operate, and applicable low-temperature synthesis process suitable for various substrates, is of great significance for promoting the practical application of GaS-based optoelectronic devices.

[0036] Therefore, this disclosure provides a novel method for preparing GaS powder.

[0037] Figure 1 This diagram schematically illustrates the mechanism of the low-temperature method for preparing GaS materials using a low-temperature deep eutectic solvent according to embodiments of this disclosure. (Reference) Figure 1 Choline chloride and urea were mixed, and GaCl3 and thiourea were added multiple times. Under the action of dual control agents, the mixture underwent in-situ sulfidation through multiple heating steps, including a pre-nucleation stage, a nucleation-growth stage, and a growth stage, to obtain gallium sulfide with high crystallinity.

[0038] Figure 2 A flowchart illustrating a method for preparing GaS powder according to an exemplary embodiment of this disclosure is shown schematically. (Reference) Figure 2 The method for preparing GaS powder according to the present disclosure may include the following steps:

[0039] S20. Choline chloride and urea are mixed, and after stirring and vacuum cooling to remove water, the first intermediate product is obtained.

[0040] First, 7-10g of choline chloride and 10-15g of urea can be mixed and stirred at 80-90℃ for 30-60 minutes to obtain a molten salt product. Next, the molten salt product can be subjected to vacuum cooling and dehydration treatment for 1-2 hours to obtain the first intermediate product.

[0041] For example, weigh 7g of choline chloride and 10g of urea, add them to a 50mL glass reagent bottle, and stir at 80-90℃ for 30-60 minutes until a completely transparent molten salt is formed. Then, cool the obtained transparent molten salt to room temperature under vacuum and store it under vacuum for 1-2 hours until all the water in the solution evaporates to obtain the first intermediate product.

[0042] S22. Under a protective atmosphere, GaCl3 is added to the first intermediate in multiple batches to obtain the second intermediate.

[0043] The embodiments disclosed herein do not limit the type of protective atmosphere, such as nitrogen or an inert gas.

[0044] Specifically, GaCl3 can be added to the first intermediate product in 3 to 5 separate additions to obtain the second intermediate product. The total amount of GaCl3 added is 1 to 1.75 g, with each addition spaced 5 to 10 minutes apart. During the process of obtaining the second intermediate product, the mixture is stirred at 80 to 90°C and 300 to 500 rpm. Furthermore, the amount of GaCl3 added each time can be the same or different.

[0045] For example, the first intermediate product obtained in step S20 is heated to 80~90℃, and 1.75g ​​of GaCl3 is added in three portions under nitrogen protection, with a stirring speed of 500rpm and a time interval of 10min between each addition of GaCl3.

[0046] S24. Thiourea is added to the second intermediate in multiple batches to obtain the third intermediate.

[0047] Specifically, thiourea is added to the second intermediate in 2 to 5 portions to obtain the third intermediate. The total amount of thiourea added is 1 to 2 g, and the mixture is stirred at 80 to 90°C during the process of obtaining the third intermediate.

[0048] S26. Add NaBH4 to the third intermediate to obtain the fourth intermediate.

[0049] Specifically, 0.1~0.3g of NaBH4 is added to the third intermediate to suppress the formation of oxides, thereby obtaining the fourth intermediate.

[0050] S28. The fourth intermediate product is annealed, and after annealing, it is washed with citric acid and centrifuged to obtain GaS powder.

[0051] Specifically, the fourth intermediate product was annealed by holding it in a vacuum tube furnace at 180-300℃ for 2-5 hours at a heating rate of 2-5℃ / min. After annealing, it was washed with 0.01-0.05M citric acid to remove organic residues, and then centrifuged to obtain GaS powder. The centrifuge speed was 3000-4000 rpm.

[0052] Furthermore, this disclosure also provides a GaS powder prepared using the above-described GaS powder preparation method.

[0053] Based on the above GaS scheme, it is possible to synthesize GaS materials with high crystallinity at low temperatures below 300°C. This results in low melting temperatures for flexible substrate materials (such as PET and polyimide), and the low-temperature synthesis of high-quality GaS materials is of significant value for the integration of flexible semiconductor devices, and can promote the development of flexible optoelectronic applications such as wearable devices and wearable fabrics.

[0054] Figure 3 A flowchart illustrating a method for fabricating a GaS thin-film electrode according to an exemplary embodiment of this disclosure is shown schematically. (Reference) Figure 3 The method for preparing the GaS thin film electrode according to the present disclosure includes the following steps:

[0055] S30. Disperse GaS powder in an alcohol solvent and sonicate to obtain a dispersion.

[0056] The GaS powder used in this step is the GaS powder prepared by the method described above. Furthermore, this disclosure does not limit the type of alcohol solvent; for example, it may be one of ethanol, methanol, or isopropanol.

[0057] Specifically, 0.05~0.15g of GaS powder can be dispersed in 10mL of alcohol solvent and sonicated for 30~40min.

[0058] S32. Spray the dispersion onto the substrate surface to form a precursor electrode.

[0059] The substrate used in this disclosure can be selected from sapphire, ITO, and n-Si, with dimensions such as 10×20×0.35mm.

[0060] S34. A (NH4)2S solution is dropped onto the surface of the precursor electrode, and after vacuum sealing, it is annealed to obtain a GaS thin film electrode.

[0061] Specifically, 10-30 μL of (NH4)2S solution is dropped onto the surface of the precursor electrode as a supplement to the S source. Then, the electrode is vacuum-sealed in a tube furnace at 250-300°C for annealing for 1-3 hours, with the heating rate controlled at 2-5°C / min. After cooling to room temperature, a GaS thin film electrode is obtained.

[0062] Furthermore, this disclosure also provides a GaS thin film electrode, which is fabricated using the above-described method for preparing GaS thin film electrodes. This GaS thin film electrode exhibits an optimal response speed of 7 μs under 380 nm illumination.

[0063] Furthermore, this disclosure also provides a photodetector comprising the aforementioned GaS thin-film electrode. This device operates at 0–100 mW / cm². 2 It exhibits a linear photocurrent response within the optical power range.

[0064] For example, integrating the above-mentioned GaS thin film electrodes with the packaging structure can form an ultraviolet detector, a transparent electrode integrated detector, or a high-frequency detector.

[0065] The exemplary solution of this disclosure is described below through Embodiment 1, which may include the following steps:

[0066] Step 1: Weigh 7.4g of choline chloride and 10g of urea, add them to a 50mL glass reagent bottle, and stir at 85℃ for 40min until a completely transparent molten salt is formed.

[0067] Step 2: Cool the obtained transparent molten salt to room temperature under vacuum conditions and store it under vacuum for 1 hour until all the water in the solution evaporates.

[0068] Step 3: The product obtained in Step 2 is heated to 80°C again, and then 1.75g ​​of GaCl3 is added in three portions under nitrogen protection, with a stirring speed of 300rpm and a time interval of 5min between each addition of GaCl3.

[0069] Step 4: Add 2g of thiourea to the product obtained in step 3 in two portions, maintaining the temperature at 80℃ throughout the stirring process.

[0070] Step 5: Add 0.2g of NaBH4 to the product obtained in step 4 to inhibit the formation of oxides.

[0071] Step 6: Cool the product obtained in Step 5 to room temperature, then place it in a glass boat and keep it at 250°C for 3 hours in a vacuum tube furnace. The heating rate of the whole process is controlled at 2°C / min.

[0072] Step 7: Wash the product obtained in Step 6 with 0.01M citric acid to remove organic residue. Then, rinse with water and finally centrifuge at 4000 rpm to obtain GaS powder.

[0073] Figure 4 The XRD patterns of GaS materials at different annealing temperatures according to embodiments of this disclosure are illustrated schematically. Specifically, in addition to the annealing treatment at 250°C described above, annealing treatments at 180°C and 300°C were also performed. Figure 4 As shown, compared to 180℃ and 300℃, annealing at 250℃ resulted in the best crystallinity.

[0074] Figure 5 A schematic diagram illustrating the ultraviolet-visible diffuse reflection of a GaS material according to an embodiment of this disclosure is shown. Figure 5 The results show that the bandgap of the GaS material prepared in Example 1 of this disclosure is 2.5 eV.

[0075] Step 8: Weigh 0.1g of GaS powder obtained in Step 7, disperse it in 10mL of ethanol solution, ultrasonically disperse it for 30min, and then spray it onto the surface of a 10×20×0.35mm sapphire substrate to prepare a GaS precursor electrode.

[0076] Step 9: Add 10 μL of (NH4)2S solution to the surface of the GaS precursor electrode prepared in Step 8 as a supplement to the S source. Then, vacuum seal the electrode and place it in a tube furnace for annealing at 250°C for 1 hour, with the heating rate controlled at 2°C / min. After cooling to room temperature, the GaS thin film electrode is obtained.

[0077] Figure 6 The diagram illustrates SEM images of the GaS thin film electrode surface according to an embodiment of the present disclosure. Figure A shows the microstructure at a 10 μm scale, and Figure B shows the microstructure at a 5 μm scale.

[0078] The optical properties of the prepared GaS / sapphire substrate electrode were characterized, and it can be seen that the GaS / sapphire electrode has good photoelectric detection performance.

[0079] Figure 7 The photoelectric response curves of GaS (380 nm) material at different annealing temperatures according to embodiments of this disclosure are schematically shown. (Reference) Figure 7 As can be seen, the prepared GaS-type semiconductor thin film has the characteristics of an n-type semiconductor. The photocurrent is the largest at an annealing temperature of 250℃. Therefore, this temperature is the optimal sintering temperature.

[0080] Figure 8This schematically illustrates an embodiment of the present disclosure at 5mW / cm 2 IV test curves of GaS material under photoexcitation. (Reference) Figure 8 As can be seen, the GaS thin film prepared in Example 1 of this disclosure exhibits a linear change in current as the voltage increases, which is an important advantage in the field of sensors.

[0081] Figure 9 The photoresponse curves of the GaS material according to embodiments of the present disclosure at different optical powers are schematically shown. (Reference) Figure 9 As can be seen, GaS semiconductor thin films exhibit good photoresponse characteristics under different light intensities.

[0082] In addition, the aforementioned GaS / sapphire electrodes can be packaged to fabricate a photoelectric sensor, such as... Figure 10 As shown. The sensitivity of the sensor was then tested, with reference to... Figure 11 As can be seen, the photoelectric sensor prepared in Embodiment 1 of this disclosure has a response speed of 7μs to 380nm ultraviolet light, which is excellent.

[0083] The exemplary solution of this disclosure will be described below through Embodiment 2, which may include the following steps:

[0084] Step 1: Weigh 7.4g of choline chloride and 10g of urea, add them to a 50mL glass reagent bottle, and stir at 85℃ for 40min until a completely transparent molten salt is formed.

[0085] Step 2: Cool the obtained transparent molten salt to room temperature under vacuum conditions and store it under vacuum for 1.5 hours until all the water in the solution has evaporated.

[0086] Step 3: The product obtained in Step 2 is heated to 80°C again, and then 1.75g ​​of GaCl3 is added in three portions under nitrogen protection, with a stirring speed of 400rpm and a time interval of 7min between each addition of GaCl3.

[0087] Step 4: Add 2g of thiourea to the product obtained in step 3 in two portions, maintaining the temperature at 85℃ throughout the stirring process.

[0088] Step 5: Add 0.1g of NaBH4 to the product obtained in step 4 to inhibit the formation of oxides.

[0089] Step 6: Cool the product obtained in Step 5 to room temperature, then place it in a glass boat and keep it at 250°C for 3 hours in a vacuum tube furnace. The heating rate of the whole process is controlled at 2°C / min.

[0090] Step 7: Wash the product obtained in Step 6 with 0.03M citric acid to remove organic residue. Then, rinse with water and finally centrifuge at 4000 rpm to obtain GaS powder.

[0091] Step 8: Weigh 0.1g of GaS powder obtained in Step 7, disperse it in 10mL of ethanol solution, ultrasonically disperse it for 30min, and then spray it onto the surface of an ITO substrate of 10×20×0.35mm to prepare a GaS precursor electrode.

[0092] Step 9: Add 10 μL of (NH4)2S solution to the surface of the GaS precursor electrode prepared in Step 8 as a supplement to the S source. Then, vacuum seal the electrode and place it in a tube furnace for annealing at 280°C for 1 hour, with the heating rate controlled at 2°C / min. After cooling to room temperature, the GaS thin film electrode is obtained.

[0093] Subsequently, the optical characteristics of the GaS thin film electrode can be characterized, and a photoelectric sensor can be fabricated using the GaS thin film electrode.

[0094] The aforementioned GaS thin-film electrode exhibits n-type semiconductor characteristics. The sensitivity of a photoelectric sensor fabricated based on this GaS thin-film electrode was tested, with reference to… Figure 12 As can be seen, the photoelectric sensor prepared in Embodiment 2 of this disclosure has a response speed of 12μs to 380nm ultraviolet light.

[0095] The exemplary solution of this disclosure will be described below through Embodiment 3, which may include the following steps:

[0096] Step 1: Weigh 7.4g of choline chloride and 10g of urea, add them to a 50mL glass reagent bottle, and stir at 90℃ for 60min until a completely transparent molten salt is formed.

[0097] Step 2: Cool the obtained transparent molten salt to room temperature under vacuum conditions and store it under vacuum for 2 hours until all the water in the solution has evaporated.

[0098] Step 3: The product obtained in Step 2 is heated to 90°C again, and then 1.75g ​​of GaCl3 is added in three portions under nitrogen protection, with a stirring speed of 400rpm and a time interval of 10min between each addition of GaCl3.

[0099] Step 4: Add 2g of thiourea to the product obtained in step 3 in two portions, maintaining the temperature at 90℃ throughout the stirring process.

[0100] Step 5: Add 0.3g of NaBH4 to the product obtained in step 4 to inhibit the formation of oxides.

[0101] Step 6: Cool the product obtained in Step 5 to room temperature, then place it in a glass boat and keep it at 250°C for 3 hours in a vacuum tube furnace. The heating rate of the whole process is controlled at 2°C / min.

[0102] Step 7: Wash the product obtained in Step 6 with 0.05M citric acid to remove organic residue. Then, rinse with water and finally centrifuge at 4000 rpm to obtain GaS powder.

[0103] Step 8: Weigh 0.1g of GaS powder obtained in Step 7, disperse it in 10mL of ethanol solution, ultrasonically disperse it for 30min, and then spray it onto the surface of a 10×20×0.35mm n-Si substrate to prepare a GaS precursor electrode.

[0104] Step 9: Add 10 μL of (NH4)2S solution to the surface of the GaS precursor electrode prepared in Step 8 as a supplement to the S source. Then, vacuum seal the electrode and place it in a tube furnace for annealing at 300°C for 1 hour, with the heating rate controlled at 2°C / min. After cooling to room temperature, the GaS thin film electrode is obtained.

[0105] Subsequently, the optical characteristics of the GaS thin film electrode can be characterized, and a photoelectric sensor can be fabricated using the GaS thin film electrode.

[0106] The aforementioned GaS thin-film electrode exhibits n-type semiconductor characteristics. The sensitivity of a photoelectric sensor fabricated based on this GaS thin-film electrode was tested, with reference to… Figure 13 As can be seen, the photoelectric sensor prepared in Example 3 of this disclosure has a response speed of 17μs to 380nm ultraviolet light.

[0107] This disclosure addresses the problems of high energy consumption and limited substrate selection associated with the high-temperature processing required for the preparation of existing GaS materials, while also overcoming the limitations of low-temperature synthesis, which often results in low crystallinity, poor film uniformity, and unstable photoelectric properties. A deep eutectic solvent is used as the reaction medium to achieve controllable low-temperature growth of GaS nanostructures. The resulting GaS material exhibits excellent crystallinity and film uniformity, making it suitable for constructing photodetectors, field-effect transistors, and catalytic devices. Photodetectors prepared based on this material demonstrate excellent response speed and stability, providing a key technological path for the development of low-temperature compatible optoelectronic devices.

[0108] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0109] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0110] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0111] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A method for preparing GaS powder, characterized in that, include: Mix 7-10g of choline chloride with 10-15g of urea and stir at 80-90℃ for 30-60min to obtain a molten salt product. Perform vacuum cooling and dehydration treatment on the molten salt product to obtain a first intermediate product. Under a protective atmosphere, 1-1.75 g of GaCl3 was added to the first intermediate product in multiple batches to obtain the second intermediate product; wherein, during the process of obtaining the second intermediate product, stirring was performed at 80-90°C and 300-500 rpm. Thiourea in total amount of 1-2g is added to the second intermediate product in multiple batches to obtain the third intermediate product; wherein, during the process of obtaining the third intermediate product, stirring treatment at 80-90℃ is performed. Add 0.1~0.3g of NaBH4 to the third intermediate to obtain the fourth intermediate; The fourth intermediate product was placed in a vacuum tube furnace at 180-300°C for 2-5 hours and heated at a rate of 2-5°C / min for annealing. After annealing, it was cleaned with citric acid and centrifuged to obtain GaS powder.

2. The preparation method according to claim 1, characterized in that, The molten salt product is subjected to vacuum cooling and dehydration treatment to obtain a first intermediate product, comprising: The molten salt product is subjected to vacuum cooling and dehydration treatment for 1-2 hours to obtain the first intermediate product.

3. The preparation method according to claim 1, characterized in that, GaCl3, in a total amount of 1-1.75 g, is added to the first intermediate product in multiple batches to obtain the second intermediate product, comprising: GaCl3, in a total amount of 1 to 1.75 g, is added to the first intermediate product in 3 to 5 portions to obtain the second intermediate product; The interval between each addition is 5 to 10 minutes.

4. The preparation method according to claim 1 or 3, characterized in that, Thiourea, in total, is added to the second intermediate in multiple batches, in amounts of 1-2 g, to obtain the third intermediate, which includes: Thiourea, in total, is added to the second intermediate in 2 to 5 portions, with a total amount of 1 to 2 g, to obtain the third intermediate.

5. The preparation method according to claim 1, characterized in that, After annealing, the gas was cleaned with citric acid and centrifuged to obtain GaS powder, comprising: After annealing, the gas was cleaned with 0.01~0.05M citric acid and centrifuged to obtain GaS powder.

6. A GaS powder, characterized in that, It was prepared using the method for preparing GaS powder as described in any one of claims 1 to 5.

7. A method for preparing a GaS thin film electrode, characterized in that, include: GaS powder is dispersed in an alcohol solvent and sonicated to obtain a dispersion; wherein the GaS powder is prepared by the method for preparing GaS powder as described in any one of claims 1 to 5. The dispersion is sprayed onto the substrate surface to form a precursor electrode; A (NH4)2S solution was dropped onto the surface of the precursor electrode, and the electrode was annealed after vacuum sealing to obtain a GaS thin film electrode.

8. A GaS thin film electrode, characterized in that, The GaS thin film electrode was prepared using the method described in claim 7.

9. A photodetector, characterized in that, It includes a GaS thin film electrode, which is prepared using the GaS thin film electrode preparation method as described in claim 7.

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