Preparation method of gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detector
By modifying a few layers of Nb2CTx on a Ga2O3 nanorod array to form an α-Ga2O3/Nb2CTx heterojunction, the problems of low responsivity and external power supply dependence of Ga2O3 solar-blind ultraviolet photodetectors are solved, achieving self-powered, fast-response, and long-term stable solar-blind ultraviolet detection effects, which are suitable for applications such as missile early warning and optical communication.
Patent Information
- Application Number
- CN202511341905.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-19
- Publication Date
- 2026-01-06
AI Technical Summary
Existing Ga2O3 solar-blind ultraviolet photodetectors have low responsivity, slow response speed, and require external power supply. The fabrication process of Ga2O3-MXene heterojunctions is complex and costly. There is limited research on α-Ga2O3-based heterojunctions, and Ti3C2Tx is mainly used, while other types of MXenes have not been fully utilized.
An α-Ga2O3 nanorod array was prepared on a titanium substrate using hydrothermal, post-annealing, and spin-coating processes. Combined with few-layer Nb2CTx modification, an α-Ga2O3/Nb2CTx heterojunction was formed. A PEC-type self-powered solar-blind ultraviolet photodetector was then constructed using a three-electrode system.
It achieves green, environmentally friendly, energy-saving and efficient operation of self-powered solar-blind ultraviolet photodetectors, with simple manufacturing process, fast response and long-term stability, and is suitable for missile early warning, optical communication and ultraviolet imaging and other fields.
Smart Images
Figure CN121285084A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of photoelectric detection, specifically to a method for fabricating gallium oxide / MXene heterojunctions for self-powered solar-blind ultraviolet detectors. Background Technology
[0002] Solar-blind ultraviolet photodetectors can selectively detect short-wavelength ultraviolet light in the wavelength range of 200–280 nm. Unaffected by ground-level sunlight, they offer advantages such as high detection accuracy, low false alarm rate, and all-weather operation, making them promising for applications in missile early warning and tracking, secure communications, and environmental monitoring. Ultra-wide bandgap semiconductors are crucial for constructing solar-blind ultraviolet photodetectors. Ga2O3, with its bandgap (4.2–5.2 eV) falling precisely in the solar-blind ultraviolet region, is the preferred material for solar-blind ultraviolet photodetectors. However, practical applications of Ga2O3 solar-blind ultraviolet photodetectors still suffer from drawbacks such as low responsivity, slow response speed, and the need for an external power supply.
[0003] Constructing heterojunctions between Ga2O3 and other materials is one of the effective ways to improve the performance of Ga2O3 solar-blind ultraviolet photodetectors. MXene is an emerging two-dimensional material with the general structural formula M... n+1 X n T x In this model, M represents a transition metal, X represents carbon or nitrogen, and T represents a surface functional group. MXene possesses excellent conductivity, unique optical transparency, high carrier mobility, abundant surface functional groups, and the ability to form van der Waals heterojunctions with other materials. Given the unique properties of MXene, constructing Ga2O3-MXene heterojunctions will effectively improve the performance of solar-blind ultraviolet photodetectors. Although there is some research on Ga2O3-MXene heterojunction solar-blind ultraviolet photodetectors, there are still several shortcomings. First, most current Ga2O3-MXene heterojunction photodetectors are solid-state metal-semiconductor-metal (MSM) structures, which have complex fabrication processes, high manufacturing costs, and require an external power supply to operate normally. Second, the construction of Ga2O3-MXene heterojunctions mainly uses monoclinic β-Ga2O3, which has complex fabrication processes and requires high-temperature conditions. In contrast, corundum-structured α-Ga2O3 has advantages such as low-temperature synthesis and good compatibility with other materials. However, research on α-Ga2O3-based heterojunction solar-blind ultraviolet photodetectors is relatively limited. Finally, the MXene commonly used in the fabrication of Ga2O3-MXene heterojunction photodetectors is Ti3C2T. x Other types of MXenes have received little attention. Summary of the Invention
[0004] The purpose of this invention is to provide a method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector, comprising the following steps:
[0005] 1) Based on gallium nitrate seed layer solution and gallium nitrate growth solution, α-Ga2O3 nanorod arrays were prepared on titanium substrates, denoted as α-Ga2O3 / Ti;
[0006] 2) Attach high-temperature tape to one end of the α-Ga2O3 / Ti so that the high-temperature tape partially covers the substrate;
[0007] 3) Use few-slice Nb2CT x The aqueous solution was spin-coated onto the substrate area without the high-temperature adhesive tape, and then heated on a hot plate to allow the few-layer Nb2CT to form. x The modification is applied to the top of α-Ga2O3 / Ti; where the heating time is denoted as T.
[0008] 4) Repeat step 3) N times to obtain α-Ga2O3 / Nb2CT x Heterogeneous junction;
[0009] 5) Prepare α-Ga2O3 / Nb2CT x A heterojunction titanium sheet is placed on an ultrathin quartz sheet, and the titanium sheet and the ultrathin quartz sheet are encapsulated.
[0010] 6) One end of the conductive copper wire was fixed onto a titanium sheet and cured at room temperature to prepare α-Ga2O3 / Nb2CT. x Heterojunction photoanode;
[0011] 7) Using α-Ga2O3 / Nb2CT x A heterojunction photoanode is used as the working electrode, and a three-electrode system is adopted to build a PEC-type self-powered solar-blind ultraviolet photodetector.
[0012] Furthermore, the preparation steps of the gallium nitrate seed crystal layer solution are as follows: it is prepared by using hydrated gallium nitrate, ethylene glycol methyl ether and ethanolamine as raw materials through water bath heating technology; wherein, the water bath heating technology process is to heat at 40-80℃ for 20 minutes to 5 hours.
[0013] Further, in step 1), the concentration of the gallium nitrate seed crystal solution is 0.01 mol / L to 1 mol / L. The ratio of the mass of hydrated gallium nitrate, the volume of ethanolamine, and the volume of ethylene glycol methyl ether is (0.77 to 7.7):0.9:30, where mass is expressed in g and volume in mL.
[0014] In step 1), the spin-coating volume of the gallium nitrate seed crystal solution is 20 μL to 100 μL.
[0015] Furthermore, in step 1), the post-processing includes cooling, cleaning, drying, and annealing.
[0016] In step 1), the aging time at room temperature is 24 to 60 hours.
[0017] Furthermore, in step 1), when performing high-temperature annealing, the annealing process is: annealing at 400℃~550℃ for 0.5 hours~3 hours;
[0018] In the post-processing, the annealing process is as follows: annealing at 350℃~500℃ for 2 to 8 hours.
[0019] In step 1), the hydrothermal reaction process is carried out at 130℃~200℃ for 3 to 24 hours.
[0020] Furthermore, in step 1), the concentration of the gallium nitrate growth solution is 0.01 mol / L to 0.5 mol / L;
[0021] Step 2) In-slice Nb2CT x The concentration of the aqueous solution is 0.05 mg / mL to 1 mg / mL, and the spin-coating volume is 20 μL to 100 μL.
[0022] In step 2), the area covered by the high-temperature tape is one-fifth to one-quarter of the substrate area;
[0023] Furthermore, in step 4), the number of iterations N = 1 to 4.
[0024] Furthermore, in step 3), the hot plate heating process involves heating at 60℃~150℃ for 3 minutes to 1 hour.
[0025] In step 6), the room temperature curing time is 12 to 48 hours.
[0026] Further, in step 5), the titanium sheet and the ultrathin quartz sheet are encapsulated with epoxy resin AB glue; the thickness of the ultrathin quartz sheet ranges from 0.05mm to 1mm; in step 6), one end of the conductive copper wire is fixed to the titanium sheet with silver conductive glue.
[0027] Furthermore, in step 7), the three-electrode system refers to α-Ga2O3 / Nb2CT. x The heterojunction photoanode is used as the working electrode, the saturated calomel electrode (SCE) is used as the reference electrode, the platinum sheet is used as the counter electrode, and the 0.5 mol / L Na₂SO₄ solution is used as the electrolyte.
[0028] In step 7), a 254nm wavelength ultraviolet lamp is used as a solar-blind ultraviolet light source.
[0029] The technical effects of this invention are undeniable, and the beneficial technical effects of this invention are as follows:
[0030] 1. This invention mainly adopts hydrothermal, post-annealing and spin coating processes, which have the advantages of simple process, easy operation and low cost.
[0031] 2. The solar-blind ultraviolet photodetector of the present invention is a self-powered type, which uses the built-in electric field as the driving force to effectively separate photogenerated electron-hole pairs. It can work continuously without external power supply and has the advantages of being green, environmentally friendly, energy-saving and efficient.
[0032] 3. The solar-blind ultraviolet photodetector of the present invention is of the PEC type, which has the advantages of simple preparation process, low manufacturing cost, large interface area between semiconductor / electrolyte, fast response speed and good long-term stability.
[0033] 4. The α-Ga2O3 / Nb2CT developed in this invention x Heterojunction solar-blind ultraviolet photodetectors exhibit typical self-powered performance, outstanding solar-blind ultraviolet light response performance, fast response speed and long-term stability, and have certain application prospects in missile early warning and tracking, optical communication and ultraviolet imaging. Attached Figure Description
[0034] Figure 1 α-Ga2O3 / Nb2CT x The encapsulation process of heterojunction photoanodes.
[0035] Figure 2 α-Ga2O3 / Nb2CT x Scanning electron microscope (SEM) image of a heterojunction.
[0036] Figure 3 α-Ga2O3 / Nb2CT x It curves of a heterojunction photodetector under 0V bias and different intensities of solar-blind ultraviolet light.
[0037] Figure 4 α-Ga2O3 / Nb2CT x Heterojunction photodetectors at 0V bias and 100μW / cm 2 Transient response time under intense solar blind ultraviolet light irradiation.
[0038] Figure 5 α-Ga2O3 / Nb2CT x Heterojunction photodetectors at 0V bias and 100μW / cm 2 Long-term stability test curves under solar blind ultraviolet light intensity. Detailed Implementation
[0039] The present invention will be further described below with reference to embodiments, but it should not be construed that the scope of the present invention is limited to the following embodiments. Various substitutions and modifications made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention should be included within the scope of protection of the present invention.
[0040] Example 1:
[0041] See Figures 1 to 5 A method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector includes the following steps:
[0042] 1) Based on gallium nitrate seed layer solution and gallium nitrate growth solution, α-Ga2O3 nanorod arrays were prepared on titanium substrates, denoted as α-Ga2O3 / Ti;
[0043] 2) Attach high-temperature tape to one end of the α-Ga2O3 / Ti so that the high-temperature tape partially covers the substrate;
[0044] 3) Use few-slice Nb2CT x The aqueous solution was spin-coated onto the substrate area without the high-temperature adhesive tape, and then heated on a hot plate to allow the few-layer Nb2CT to form. x The modification is applied to the top of α-Ga2O3 / Ti; where the heating time is denoted as T.
[0045] 4) Repeat step 3) N times to obtain α-Ga2O3 / Nb2CT x Heterogeneous junction;
[0046] 5) Prepare α-Ga2O3 / Nb2CT x A heterojunction titanium sheet is placed on an ultrathin quartz sheet, and the titanium sheet and the ultrathin quartz sheet are encapsulated.
[0047] 6) One end of the conductive copper wire was fixed onto a titanium sheet and cured at room temperature to prepare α-Ga2O3 / Nb2CT. x Heterojunction photoanode;
[0048] 7) Using α-Ga2O3 / Nb2CT x A heterojunction photoanode is used as the working electrode, and a three-electrode system is adopted to build a PEC-type self-powered solar-blind ultraviolet photodetector.
[0049] Example 2:
[0050] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as in Example 1. Further, the preparation steps of gallium nitrate seed crystal layer solution are as follows: it is prepared by water bath heating technology using hydrated gallium nitrate, ethylene glycol methyl ether and ethanolamine as raw materials; wherein, the water bath heating technology process is heating at 40-80°C for 20 minutes to 5 hours.
[0051] Example 3:
[0052] The method for preparing a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector is the same as that in any one of Examples 1-2, except that the concentration of the gallium nitrate seed layer solution in step 1) is 0.01 mol / L to 1 mol / L. The ratio of the mass of hydrated gallium nitrate, the volume of ethanolamine, and the volume of ethylene glycol monomethyl ether is (0.77-7.7):0.9:30, where mass is expressed in g and volume in mL.
[0053] In step 1), the spin-coating volume of the gallium nitrate seed crystal solution is 20 μL to 100 μL.
[0054] Example 4:
[0055] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-3. Further, in step 1), the post-processing includes cooling, cleaning, drying, and annealing.
[0056] In step 1), the aging time at room temperature is 24 to 60 hours.
[0057] Example 5:
[0058] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-4. Further, in step 1), when performing high-temperature annealing, the annealing process is: annealing at 400℃~550℃ for 0.5 hours to 3 hours.
[0059] In the post-processing, the annealing process is as follows: annealing at 350℃~500℃ for 2 to 8 hours.
[0060] In step 1), the hydrothermal reaction process is carried out at 130℃~200℃ for 3 to 24 hours.
[0061] Example 6:
[0062] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-5, except that the concentration of gallium nitrate growth solution in step 1) is 0.01 mol / L to 0.5 mol / L.
[0063] Step 2) In-slice Nb2CT x The concentration of the aqueous solution is 0.05 mg / mL to 1 mg / mL, and the spin-coating volume is 20 μL to 100 μL. In step 2), the area covered by the high-temperature tape is one-fifth to one-quarter of the substrate area.
[0064] Example 7:
[0065] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-6, except that in step 4), the number of times N = 1 to 4.
[0066] Example 8:
[0067] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-7. Further, in step 3), the hot plate heating process is heated at 60℃~150℃ for 3 minutes to 1 hour.
[0068] In step 6), the room temperature curing time is 12 to 48 hours.
[0069] Example 9:
[0070] The method for preparing gallium oxide / MXene heterojunction for self-powered solar-blind ultraviolet detectors is the same as any one of Examples 1-8. Further, in step 5), the titanium sheet and the ultrathin quartz sheet are encapsulated with epoxy resin AB glue; the thickness of the ultrathin quartz sheet is in the range of 0.05mm to 1mm; in step 6), one end of the conductive copper wire is fixed to the titanium sheet with silver conductive glue.
[0071] Example 10:
[0072] The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector is the same as any one of Examples 1-9. Further, in step 7), the three-electrode system refers to α-Ga₂O₃ / Nb₂CT. x The heterojunction photoanode is used as the working electrode, the saturated calomel electrode (SCE) is used as the reference electrode, the platinum sheet is used as the counter electrode, and the 0.5 mol / L Na₂SO₄ solution is used as the electrolyte.
[0073] In step 7), a 254nm wavelength ultraviolet lamp is used as a solar-blind ultraviolet light source.
[0074] Example 11:
[0075] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction includes the following steps:
[0076] S1. Fabrication of α-Ga₂O₃ nanorod arrays on titanium substrates. A gallium nitrate seed layer solution was prepared using hydrated gallium nitrate, ethylene glycol methyl ether, and ethanolamine as raw materials via a water bath heating technique. After room temperature aging, the solution was spin-coated onto a cleaned Ti wafer, followed by high-temperature annealing. The annealed Ti wafer was then immersed in the gallium nitrate growth solution for a hydrothermal reaction. After cooling, cleaning, drying, and annealing, an α-Ga₂O₃ nanorod array (abbreviated as α-Ga₂O₃ / Ti) was obtained grown on the Ti wafer.
[0077] S2, α-Ga2O3 / Nb2CT x Fabrication of heterojunction photoanodes. High-temperature adhesive tape was attached to one end of the α-Ga₂O₃ / Ti substrate, covering approximately one-fifth of the entire substrate, and a few-layer Nb₂CT was then applied. x An aqueous solution was spin-coated onto a substrate portion without the high-temperature adhesive tape, heated on a hot plate, and the spin-coating / heating process was repeated to obtain α-Ga₂O₃ / Nb₂CT. x A heterojunction was formed by placing the two materials on a clean, ultrathin quartz wafer and encapsulating them together with epoxy resin AB glue. Finally, one end of a conductive copper wire was fixed to the Ti wafer with silver conductive adhesive, and the mixture was cured at room temperature to obtain α-Ga₂O₃ / Nb₂CT. x Heterojunction photoanode.
[0078] S3. Construction of a photoelectrochemical (PEC) type self-powered solar-blind ultraviolet photodetector. A PEC type self-powered solar-blind ultraviolet photodetector was constructed using a three-electrode system, with a 254nm wavelength ultraviolet lamp as the solar-blind ultraviolet light source.
[0079] Example 12:
[0080] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction is described, with the same technical content as in Example 11. Further, in step S1, the water bath heating process is performed at 40-80°C for 20 minutes to 5 hours.
[0081] Example 13:
[0082] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-12, further wherein the room temperature aging time in step S1 is 24-60 hours.
[0083] Example 14:
[0084] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-13, further wherein the concentration of the gallium nitrate seed crystal layer solution in step S1 is 0.01 to 1 mol / L.
[0085] Example 15:
[0086] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-14, further wherein the spin-coating volume of the gallium nitrate seed crystal layer solution in step S1 is 20-100 μL.
[0087] Example 16:
[0088] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-15, further wherein the first annealing process in step S1 is annealing at 400-550℃ for 0.5-3 hours, and the second annealing process is annealing at 350-500℃ for 2-8 hours.
[0089] Example 17:
[0090] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-16, further wherein the hydrothermal reaction process in step S1 is a hydrothermal reaction at 130-200℃ for 3-24 hours.
[0091] Example 18:
[0092] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-17, further wherein the concentration of gallium nitrate growth solution in step S1 is 0.01-0.5 mol / L.
[0093] Example 19:
[0094] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, with the technical content being the same as any one of Examples 11-18, further comprising the use of few-layer Nb2CT in step S2. x The concentration of the aqueous solution is 0.05–1 mg / mL, and the spin-coating volume is 20–100 μL.
[0095] Example 20:
[0096] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-19, further wherein the spin coating / heating process in step S2 is repeated 1 to 4 times.
[0097] Example 21:
[0098] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-20, further wherein the room temperature curing time in step S2 is 12-48 hours.
[0099] Example 22:
[0100] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-21, further wherein the hot plate heating process in step S2 is heating at 60-150°C for 3 minutes to 1 hour.
[0101] Example 23:
[0102] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, the technical content of which is the same as any one of Examples 11-22, further wherein the three-electrode system in step S3 refers to α-Ga2O3 / Nb2CT x The heterojunction photoanode is used as the working electrode, the saturated calomel electrode (SCE) is used as the reference electrode, the platinum sheet is used as the counter electrode, and the 0.5 mol / L Na2SO4 solution is used as the electrolyte.
[0103] Example 24:
[0104] A high-performance self-powered solar-blind ultraviolet photodetector prepared by any one of the preparation methods described in Examples 1-23 includes a titanium sheet and a three-electrode system located on the surface of the titanium sheet.
[0105] The three-electrode system includes a working electrode, a reference electrode, and a counter electrode;
[0106] α-Ga2O3 / Nb2CT x The heterojunction photoanode is the working electrode, the saturated calomel electrode (SCE) is the reference electrode, and the platinum sheet is the counter electrode.
[0107] The titanium sheet is placed in the electrolyte.
[0108] Example 25:
[0109] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, comprising the following steps:
[0110] Step 1: Add 0.9 mL of monoethanolamine, 3.8361 g of gallium nitrate, and 30 mL of ethylene glycol methyl ether sequentially to a beaker. Heat and stir in a 60°C water bath for 1 hour, then age at room temperature for 36 hours to obtain a 0.5 mol / L gallium nitrate seed layer solution. Take 50 μL of the gallium nitrate seed layer solution and spin-coat it onto a cleaned Ti wafer. Anneal at 500°C for 1 hour. Place the annealed Ti wafer in a 0.04 mol / L gallium nitrate aqueous solution and hydrothermally react at 150°C for 12 hours. After cooling, cleaning, and drying, anneal at 400°C for 4 hours to obtain an α-Ga₂O₃ nanorod array (abbreviated as α-Ga₂O₃ / Ti) grown on the Ti wafer.
[0111] Step 2: Apply high-temperature adhesive tape to one end of the α-Ga2O3 / Ti substrate, covering approximately one-fifth of the entire substrate. Then, apply 50 μL of a 0.5 mg / mL few-layer Nb2CT solution. x The aqueous solution was spin-coated onto the substrate portion without the high-temperature adhesive tape, and then heated at 110°C for 15 minutes on a hot plate. This spin-coating / heating process was repeated twice to obtain α-Ga₂O₃ / Nb₂CT. x A heterojunction was formed by placing the two materials on a clean, ultrathin quartz wafer and encapsulating them together with epoxy resin AB glue. Finally, one end of a conductive copper wire was fixed to the Ti wafer with silver conductive adhesive, and the mixture was cured at room temperature for 12 hours to obtain α-Ga₂O₃ / Nb₂CT. x Heterojunction photoanode. A schematic diagram of this step is shown below. Figure 1 As shown.
[0112] The morphology of the obtained heterojunction was observed using scanning electron microscopy, and its SEM image is shown below. Figure 2 As shown, few-slice Nb2CT can be observed. x Successful modification on the top of the α-Ga2O3 nanorod array confirms the α-Ga2O3 / Nb2CT modification. x The formation of heterojunctions.
[0113] S3. A PEC-type self-powered solar-blind ultraviolet photodetector was constructed using a standard three-electrode system, with α-Ga2O3 / Nb2CT. x The heterojunction photoanode serves as the working electrode, the saturated calomel electrode (SCE) as the reference electrode, a platinum sheet as the counter electrode, and a 0.5 mol / L Na₂SO₄ solution as the electrolyte. A 254 nm wavelength ultraviolet lamp is used as the solar-blind ultraviolet light source.
[0114] α-Ga2O3 / Nb2CT obtained by testing on an electrochemical workstation x Photoelectric properties of heterojunction solar-blind ultraviolet photodetectors. Figure 3 α-Ga2O3 / Nb2CT x It curves of a heterojunction photodetector under 0V bias and different intensities of solar-blind ultraviolet light. Figure 4 α-Ga2O3 / Nb2CT x Heterojunction photodetectors at 0V bias and 100μW / cm 2 Transient response time under intense solar blind ultraviolet light irradiation. Figure 5 α-Ga2O3 / Nb2CT x Heterojunction photodetectors at 0V bias and 100μW / cm 2 Long-term stability test curves under solar-blind ultraviolet light irradiation. It can be seen that α-Ga₂O₃ / Nb₂CT... xHeterojunction photodetectors exhibit typical self-powered characteristics, excellent solar-blind ultraviolet response, fast response speed, and long-term stability. α-Ga2O3 / Nb2CT x The heterojunction photodetector has a photocurrent-to-dark-current ratio of 58.1, a responsivity of 35.4 mA / W, a detectivity of 2.6 × 10¹¹ Jones, and a response time of 0.2 s / 0.1 s.
[0115] Example 26:
[0116] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, comprising the following steps:
[0117] Step 1: Take 180 μL of monoethanolamine, 0.767 g of gallium nitrate, and 30 mL of ethylene glycol methyl ether, and add them sequentially to a beaker. Heat and stir in an 80°C water bath for 20 minutes, then age at room temperature for 24 hours to obtain a 0.1 mol / L gallium nitrate seed layer solution. Take 75 μL of the gallium nitrate seed layer solution and spin-coat it onto a cleaned Ti wafer. Anneal at 400°C for 3 hours. Place the annealed Ti wafer in a 0.01 mol / L gallium nitrate aqueous solution and hydrothermally react at 130°C for 24 hours. After cooling, cleaning, and drying, anneal at 550°C for 2 hours to obtain an α-Ga₂O₃ nanorod array (abbreviated as α-Ga₂O₃ / Ti) grown on the Ti wafer.
[0118] Step 2: Apply high-temperature adhesive tape to one end of the α-Ga2O3 / Ti substrate, covering approximately one-fifth of the entire substrate. Add 20 μL of few-layer Nb2CT at a concentration of 1.0 mg / mL. x The aqueous solution was spin-coated onto the substrate portion without the high-temperature adhesive tape, and then heated at 150°C for 3 minutes on a hot plate to obtain α-Ga₂O₃ / Nb₂CT. x A heterojunction was formed by placing the two materials on a clean, ultrathin quartz wafer and encapsulating them together with epoxy resin AB glue. Finally, one end of a conductive copper wire was fixed to the Ti wafer with silver conductive adhesive, and the mixture was cured at room temperature for 24 hours to obtain α-Ga₂O₃ / Nb₂CT. x Heterojunction photoanode.
[0119] S3. A PEC-type self-powered solar-blind ultraviolet photodetector was constructed using a standard three-electrode system, with α-Ga2O3 / Nb2CT. x The heterojunction photoanode serves as the working electrode, the SCE as the reference electrode, the platinum sheet as the counter electrode, and a 0.5 mol / L Na₂SO₄ solution as the electrolyte. A 254 nm wavelength ultraviolet lamp is used as the solar-blind ultraviolet light source.
[0120] α-Ga2O3 / Nb2CT obtained by testing on an electrochemical workstation xPhotoelectric properties of heterojunction solar-blind ultraviolet photodetectors. α-Ga₂O₃ / Nb₂CT x The heterojunction photodetector exhibits typical self-powered characteristics, excellent solar-blind ultraviolet response characteristics, fast response speed and long-term stability, with a light-to-dark current ratio of 56.3, a responsivity of 33.6 mA / W, a detectivity of 2.48 × 10¹¹ Jones, and a response speed of 0.23 s / 0.12 s.
[0121] Example 27:
[0122] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, comprising the following steps:
[0123] Step 1: Take 180 μL of monoethanolamine, 0.0767 g of gallium nitrate, and 30 mL of ethylene glycol methyl ether, and add them sequentially to a beaker. Heat and stir in a 40°C water bath for 5 hours, then age at room temperature for 48 hours to obtain a 0.01 mol / L gallium nitrate seed crystal layer solution. Take 100 μL of the gallium nitrate seed crystal layer solution and spin-coat it onto a cleaned Ti wafer. Anneal at 550°C for 0.5 hours. Place the annealed Ti wafer in a 0.2 mol / L gallium nitrate aqueous solution and hydrothermally react at 180°C for 8 hours. After cooling, cleaning, and drying, anneal at 350°C for 8 hours to obtain an α-Ga₂O₃ nanorod array (abbreviated as α-Ga₂O₃ / Ti) grown on the Ti wafer.
[0124] Step 2: Apply high-temperature adhesive tape to one end of the α-Ga2O3 / Ti substrate, covering approximately one-fifth of the entire substrate. Then, apply 100 μL of 0.05 mg / mL few-layer Nb2CT. x The aqueous solution was spin-coated onto the substrate portion without the high-temperature adhesive tape, and then heated at 80°C for 30 minutes on a hot plate. This spin-coating / heating process was repeated four times to obtain α-Ga₂O₃ / Nb₂CT. x A heterojunction was formed by placing the two materials on a clean, ultrathin quartz wafer and encapsulating them together with epoxy resin AB glue. Finally, one end of a conductive copper wire was fixed to the Ti wafer with silver conductive adhesive, and the mixture was cured at room temperature for 36 hours to obtain α-Ga₂O₃ / Nb₂CT. x Heterojunction photoanode.
[0125] S3. A PEC-type self-powered solar-blind ultraviolet photodetector was constructed using a standard three-electrode system, with α-Ga2O3 / Nb2CT. x The heterojunction photoanode serves as the working electrode, the SCE as the reference electrode, the platinum sheet as the counter electrode, and a 0.5 mol / L Na₂SO₄ solution as the electrolyte. A 254 nm wavelength ultraviolet lamp is used as the solar-blind ultraviolet light source.
[0126] α-Ga2O3 / Nb2CT obtained by testing on an electrochemical workstation xPhotoelectric properties of heterojunction solar-blind ultraviolet photodetectors. α-Ga₂O₃ / Nb₂CT x The heterojunction photodetector exhibits typical self-powered characteristics, excellent solar-blind ultraviolet response characteristics, fast response speed and long-term stability, with a light-to-dark current ratio of 54.7, a responsivity of 32.8 mA / W, a detectivity of 2.49 × 10¹¹ Jones, and a response speed of 0.26 s / 0.13 s.
[0127] Example 28:
[0128] A method for fabricating a high-performance self-powered solar-blind ultraviolet photodetector based on a gallium oxide / MXene heterojunction, comprising the following steps:
[0129] Step 1: Add 0.9 mL of monoethanolamine, 7.6722 g of gallium nitrate, and 30 mL of ethylene glycol methyl ether sequentially to a beaker. Heat and stir in a 70°C water bath for 1 hour, then age at room temperature for 60 hours to obtain a 1 mol / L gallium nitrate seed layer solution. Take 20 μL of the gallium nitrate seed layer solution and spin-coat it onto a cleaned Ti wafer. Anneal at 450°C for 2 hours. Place the annealed Ti wafer in a 0.5 mol / L gallium nitrate aqueous solution and hydrothermally react at 200°C for 3 hours. After cooling, cleaning, and drying, anneal at 450°C for 3 hours to obtain an α-Ga₂O₃ nanorod array (abbreviated as α-Ga₂O₃ / Ti) grown on the Ti wafer.
[0130] Step 2: Apply high-temperature adhesive tape to one end of the α-Ga2O3 / Ti substrate, covering approximately one-fifth of the entire substrate. Then, apply 75 μL of few-layer Nb2CT at a concentration of 0.25 mg / mL. x The aqueous solution was spin-coated onto the substrate portion without the high-temperature adhesive tape, and then heated at 60°C for 1 hour on a hot plate. This spin-coating / heating process was repeated three times to obtain α-Ga₂O₃ / Nb₂CT. x A heterojunction was formed by placing the two materials on a clean, ultrathin quartz wafer and encapsulating them together with epoxy resin AB glue. Finally, one end of a conductive copper wire was fixed to the Ti wafer with silver conductive adhesive, and the mixture was cured at room temperature for 48 hours to obtain α-Ga₂O₃ / Nb₂CT. x Heterojunction photoanode.
[0131] S3. A PEC-type self-powered solar-blind ultraviolet photodetector was constructed using a standard three-electrode system, with α-Ga2O3 / Nb2CT. x The heterojunction photoanode serves as the working electrode, the SCE as the reference electrode, the platinum sheet as the counter electrode, and a 0.5 mol / L Na₂SO₄ solution as the electrolyte. A 254 nm wavelength ultraviolet lamp is used as the solar-blind ultraviolet light source.
[0132] α-Ga2O3 / Nb2CT obtained by testing on an electrochemical workstation xPhotoelectric properties of heterojunction solar-blind ultraviolet photodetectors. α-Ga₂O₃ / Nb₂CT x The heterojunction photodetector exhibits typical self-powered characteristics, excellent solar-blind ultraviolet response characteristics, fast response speed and long-term stability, with a light-to-dark current ratio of 52.6, a responsivity of 35.4 mA / W, a detectivity of 2.38 × 10¹¹ Jones, and a response speed of 0.29 s / 0.15 s.
Claims
1. A method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector, characterized in that, Includes the following steps: 1) Based on gallium nitrate seed layer solution and gallium nitrate growth solution, α-Ga2O3 nanorod arrays were prepared on titanium substrates, denoted as α-Ga2O3 / Ti; 2) Apply high-temperature tape to one end of the α-Ga2O3 / Ti substrate, ensuring the tape partially covers the substrate. 3) Use few-slice Nb2CT x The aqueous solution was spin-coated onto the substrate area without the high-temperature adhesive tape, and then heated on a hot plate to allow the few-layer Nb2CT to form. x The modification is applied to the top of α-Ga2O3 / Ti; where the heating time is denoted as T. 4) Repeat step 3) N times to obtain α-Ga2O3 / Nb2CT x Heterogeneous junction; 5) Prepare α-Ga2O3 / Nb2CT x A heterojunction titanium sheet is placed on an ultrathin quartz sheet, and the titanium sheet and the ultrathin quartz sheet are encapsulated. 6) One end of the conductive copper wire was fixed onto a titanium sheet and cured at room temperature to prepare α-Ga2O3 / Nb2CT. x Heterojunction photoanode; 7) Using α-Ga2O3 / Nb2CT x A heterojunction photoanode is used as the working electrode, and a three-electrode system is adopted to build a PEC-type self-powered solar-blind ultraviolet photodetector.
2. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, The steps for preparing an α-Ga2O3 nanorod array on a titanium substrate include: spin-coating a gallium nitrate seed layer solution aged at room temperature onto the surface of a titanium sheet, followed by high-temperature annealing, immersing the annealed titanium sheet in a gallium nitrate growth solution for hydrothermal reaction, and performing post-treatment to obtain an α-Ga2O2 nanorod array grown on a titanium substrate, denoted as α-Ga2O3 / Ti. The preparation steps of the gallium nitrate seed crystal layer solution are as follows: it is prepared by using hydrated gallium nitrate, ethylene glycol methyl ether and ethanolamine as raw materials through water bath heating technology; wherein the water bath heating technology process is heating at 40-80℃ for 20 minutes to 5 hours.
3. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 1), the concentration of the gallium nitrate seed crystal layer solution is 0.01 mol / L to 1 mol / L, and the ratio of the mass of hydrated gallium nitrate, the volume of ethanolamine, and the volume of ethylene glycol methyl ether is (0.77 to 7.7): 0.9:30, where the mass is expressed in g and the volume is expressed in mL. In step 1), the spin-coating volume of the gallium nitrate seed crystal solution is 20 μL to 100 μL.
4. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that: In step 1), the post-processing includes cooling, cleaning, drying, and annealing. In step 1), the aging time at room temperature is 24 to 60 hours.
5. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 4, characterized in that, In step 1), when performing high-temperature annealing, the annealing process is as follows: annealing at 400℃~550℃ for 0.5 hours~3 hours; In the post-processing, the annealing process is as follows: annealing at 350℃~500℃ for 2 to 8 hours. In step 1), the hydrothermal reaction process is carried out at 130℃~200℃ for 3 to 24 hours.
6. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 1), the concentration of the gallium nitrate growth solution is 0.01 mol / L to 0.5 mol / L; Step 2) In-slice Nb2CT x The concentration of the aqueous solution is 0.05 mg / mL to 1 mg / mL, and the spin-coating volume is 20 μL to 100 μL.
7. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 4), the number of iterations N = 1 to 4.
8. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 2), the area covered by the high-temperature tape is one-fifth to one-quarter of the substrate area; Step 3) The hot plate heating process involves heating at 60℃~150℃ for 3 minutes to 1 hour. In step 6), the room temperature curing time is 12 to 48 hours.
9. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 5), the titanium sheet and the ultrathin quartz sheet are encapsulated with epoxy resin AB glue; the thickness of the ultrathin quartz sheet ranges from 0.05 mm to 1 mm. In step 6), one end of the conductive copper wire is fixed to the titanium sheet using silver conductive adhesive.
10. The method for fabricating a gallium oxide / MXene heterojunction for a self-powered solar-blind ultraviolet detector according to claim 1, characterized in that, In step 7), the three-electrode system refers to α-Ga2O3 / Nb2CT. x The heterojunction photoanode is used as the working electrode, the saturated calomel electrode (SCE) is used as the reference electrode, the platinum sheet is used as the counter electrode, and the 0.5 mol / L Na₂SO₄ solution is used as the electrolyte. In step 7), a 254nm wavelength ultraviolet lamp is used as a solar-blind ultraviolet light source.