Preparation method of PEC type linear ultraviolet detector based on Ga2O3 / GaN nanorod

Abstract

The invention provides a preparation method of a PEC type linear ultraviolet detector based on a Ga2O3 / GaN nanorod. Comprising the following steps: step 1, pretreating a Ti wire substrate; step 2, preparing a GaOOH nanorod on the Ti wire substrate; step 3, annealing the GaOOH nanorod, so as to obtain an alpha-Ga2O3 nanorod; step 4, carrying out ammonification on the alpha-Ga2O3 nanorod, so as to obtain a Ga2O3 / GaN nanorod; and step 5, packaging the Ga2O3 / GaN photo-anode and a counter electrode, and injecting a Na2SO4 electrolyte to obtain the PEC type linear ultraviolet detector based on the Ga2O3 / GaN nanorod. The preparation method of the PEC type ultraviolet detector based on the Ga2O3 / GaN nanorod is provided for the first time, and compared with a pure alpha-Ga2O3 detector, the response performance of the ultraviolet detector is improved, the response time is shortened, self-energy supply can be achieved, the manufacturing method is simple, and the preparation cost is low.

Description

Technical Field

[0001] The present invention relates to the field of ultraviolet detectors, and in particular to a method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods. Background Art

[0002] The vigorous development of science and technology has driven the advancement of the optoelectronic information industry, driving a growing demand for photodetectors. Ultraviolet light has proven beneficial in sterilization, radiation curing, anti-counterfeiting, and detection. However, long-term exposure to excessive ultraviolet radiation significantly increases the risk of skin cancer, posing a health threat. Ultraviolet light comes not only from daily sunlight, but also from human luminescence and high-temperature equipment. UV detectors are increasingly being used in military and everyday applications, such as biological analysis, environmental monitoring, flame detection, and information storage.

[0003] Photoelectrochemical UV detectors have attracted attention due to their simple structure, excellent response performance, simple process, and self-powered design. Photoelectrochemical UV detectors are primarily composed of a photoanode, a counter electrode, and an electrolyte. Their working principle is as follows: First, light absorption: When ultraviolet light within a certain wavelength range strikes the detector photoanode, the photon energy is high enough to excite electrons in the material, generating photogenerated electrons and holes. Second, carrier migration: Holes diffuse to the semiconductor photoanode, and electrons are transferred to the counter electrode via an external circuit. Third, chemical reaction: Holes receive an electron from reduced ions at the interface between the photoanode and the electrolyte. Ions in the electrolyte diffuse to the counter electrode, where, under the catalytic action of Pt, the electrons transferred to the counter electrode are reduced. The products diffuse to the interface between the photoanode and the electrolyte, providing electrons to reduce the semiconductor photoanode, completing a cycle.

[0004] Ga2O3 is a direct bandgap wide bandgap semiconductor material with high photoelectric conversion efficiency, good temperature stability and low dark current, and has therefore attracted widespread attention in the field of ultraviolet detection. However, how to prepare a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods has not been reported. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing a PEC type linear ultraviolet detector based on Ga2O3 / GaN nanorods.

[0006] The present invention is achieved through the following technical solutions:

[0007] The present invention relates to a method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods, comprising the following steps:

[0008] Step 1, pre-treating the Ti wire substrate;

[0009] Step 2, preparing GaOOH nanorods on a Ti wire substrate using a hydrothermal method;

[0010] Step 3, annealing the GaOOH nanorods to obtain α-Ga2O3 nanorods;

[0011] Step 4, ammoniation of the α-Ga2O3 nanorods to convert part of the α-Ga2O3 into GaN to obtain Ga2O3 / GaN nanorods;

[0012] Step 5: Encapsulate the Ga2O3 / GaN photoanode and the counter electrode, inject Na2SO4 electrolyte, and obtain a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods.

[0013] Preferably, in step 1, the Ti wire substrate pretreatment is specifically: placing the Ti wire substrate in acetone, anhydrous ethanol, and deionized water in sequence, performing ultrasonic cleaning for 15 minutes, and drying.

[0014] Preferably, in step 2, the specific method for preparing GaOOH nanorods on the Ti wire substrate by the hydrothermal method is: placing the Ti wire substrate in a 50 mL polytetrafluoroethylene-lined stainless steel autoclave, adding the precursor solution, sealing it, placing it in a hydrothermal reactor, performing a hydrothermal reaction, and then naturally cooling it to room temperature.

[0015] Preferably, the precursor solution is a gallium nitrate aqueous solution, and its preparation method is: add 4.992g of gallium nitrate into 50ml of deionized water, fully dissolve it, and stir for 20 minutes to obtain the gallium nitrate aqueous solution.

[0016] Preferably, the hydrothermal reaction is carried out under the following conditions: heating the oven to 150° C., maintaining the temperature for 18 h, and then cooling the oven to room temperature.

[0017] Preferably, in step 3, the annealing treatment is specifically as follows: heating the slide rail furnace to 400° C., maintaining the temperature for 4 hours, and then cooling the furnace to room temperature to obtain α-Ga2O3 nanorods.

[0018] Preferably, in step 4, the specific steps of ammoniation of the α-Ga2O3 nanorods are: placing the annealed α-Ga2O3 nanorods into a crucible, placing them together into a slide rail furnace, heating the slide rail furnace to 900°C, introducing ammonia and argon at 30sccm and 20sccm respectively, and maintaining for 10 minutes to obtain Ga2O3 / GaN nanorods.

[0019] Preferably, in step 5, the packaging method is: packaging the Ga2O3 / GaN photoanode, the counter electrode and the reference electrode relative to each other at a certain distance, and injecting electrolyte.

[0020] Preferably, the counter electrode is a Pt electrode, the reference electrode is a saturated calomel electrode; and the electrolyte is a 0.5M Na2SO4 aqueous solution.

[0021] The present invention has the following advantages:

[0022] This paper proposes a method for fabricating a PEC-type UV detector based on Ga2O3 / GaN nanorods. Using a titanium wire as a substrate, α-Ga2O3 nanorods are hydrothermally prepared and annealed on the titanium wire. The prepared α-Ga2O3 is then aminated to form Ga2O3 / GaN nanorods. The prepared Ga2O3 / GaN photoanode, counter electrode, and reference electrode are then packaged and filled with electrolyte to form a PEC-type UV detector based on Ga2O3 / GaN nanorods. Compared to pure α-Ga2O3 detectors, this UV detector exhibits improved response performance, shortened response time, and self-powered operation. Its fabrication method is simple and inexpensive. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a partially enlarged SEM image of the PEC-type UV detector of Ga2O3 / GaN nanorods prepared in the present invention;

[0024] Figure 2 This is an SEM image of the entire Ga2O3 / GaN nanorod PEC-type UV detector prepared by the present invention;

[0025] Figure 3 The PEC type ultraviolet detector based on Ga2O3 / GaN nanorods prepared by the present invention is J sc The time response characteristic diagram of the signal switching instantaneously with light;

[0026] Figure 4 This is a response recovery curve of the PEC-type ultraviolet detector based on Ga2O3 / GaN nanorods prepared in the present invention;

[0027] Figure 5 TEM lattice fringe image of Ga2O3 / GaN nanorods prepared in the present invention;

[0028] Figure 6 This is the XPS image of Ga2O3 / GaN nanorods prepared in the present invention. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to specific embodiments. It should be noted that the following embodiments are only for further explanation of the present invention, but the protection scope of the present invention is not limited to the following embodiments.

[0030] Example 1

[0031] This embodiment relates to a method for preparing a PEC-type ultraviolet detector based on Ga2O3 / GaN nanorods, and the steps are as follows:

[0032] Step (1), pre-treating the titanium wire substrate: placing the titanium wire substrate in acetone, anhydrous ethanol, and deionized water in sequence, performing ultrasonic cleaning for 15 minutes, and drying;

[0033] Step (2), preparing GaOOH nanorods on a Ti wire substrate using a hydrothermal method:

[0034] The titanium wire substrate was placed in a 50 mL polytetrafluoroethylene-lined stainless steel autoclave, and the precursor solution (gallium nitrate aqueous solution) was added. The autoclave was sealed and placed in a hydrothermal reactor for hydrothermal reaction. After the hydrothermal reaction was completed, the autoclave was naturally cooled to room temperature.

[0035] The precursor solution was prepared by adding 4.992 g of gallium nitrate to 50 ml of deionized water, dissolving the mixture completely, and stirring for 20 minutes to obtain a gallium nitrate aqueous solution.

[0036] Step (3), annealing the GaOOH nanorods to obtain α-Ga2O3 nanorods; the specific steps are: heating the slide furnace to 400°C, maintaining it for 4 hours, and then cooling it to room temperature with the furnace to obtain α-Ga2O3 nanorods;

[0037] Step (4), ammoniation of the α-Ga2O3 nanorods to convert part of the α-Ga2O3 into GaN, thereby obtaining Ga2O3 / GaN nanorods;

[0038] The annealed α-Ga2O3 nanorods were placed in a crucible and placed in a sliding rail furnace. The sliding rail furnace was heated to 900°C and ammonia and argon were introduced at 30 and 20 sccm, respectively, for 10 minutes to obtain Ga2O3 / GaN nanorods.

[0039] Step (5), encapsulating the PEC type ultraviolet detector based on Ga2O3 / GaN nanorods: the photoanode, the counter electrode Pt and the saturated calomel electrode of the prepared PEC type ultraviolet detector based on Ga2O3 / GaN nanorods are relatively encapsulated at a certain distance, and 0.5M Na2SO4 electrolyte is injected to obtain the PEC type ultraviolet detector based on Ga2O3 / GaN nanorods. Figure 1 and Figure 2 .

[0040] The PEC-type ultraviolet detector of Ga2O3 / GaN nanorods prepared in Example 1 was tested and characterized as follows:

[0041] The Jsc signal of the prepared PEC type UV detector based on Ga2O3 / GaN nanorods was tested with the time response of instantaneous switching under light illumination. Figure 3 shown by Figure 3 It can be seen that the photocurrent of the Ga2O3 / GaN nanorod PEC type UV detector prepared by the present invention can reach 70μA / cm 2 , and has stable, repeatable, consistent switching cycles.

[0042] The response time of the detector (τ r ) is defined as the time required to rise to 1-1 / e of the stable photocurrent, and the recovery time (τ d ) is defined as the time required to rise to 1 / e of the stable photocurrent, given by Figure 4 It can be seen that the response time of the Ga2O3 / GaN nanorod PEC-type ultraviolet detector prepared by the present invention is about 53ms, and the recovery time is about 117ms, which has a relatively fast response and recovery speed.

[0043] The microstructure and elemental composition of the detector photoanode material were observed using TEM. Figure 5 It can be seen that the photoanode of the Ga2O3 / GaN nanorod PEC type ultraviolet detector prepared by the present invention is composed of two materials: Figure 6 It can be seen that the photoanode contains both O and N.

[0044] The device performance test was conducted using an electrochemical workstation. The test light source consisted of a xenon lamp and a monochromator. The UV wavelength was 365 nm and the intensity was 10 mW cm -2 , use a standard light intensity meter to calibrate the light intensity.

[0045] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods, characterized in that: The following steps are involved: Step 1, pre-treating the Ti wire substrate; Step 2, preparing GaOOH nanorods on a Ti wire substrate using a hydrothermal method; Step 3, annealing the GaOOH nanorods to obtain α-Ga2O3 nanorods; Step 4, ammoniation of the α-Ga2O3 nanorods to convert part of the α-Ga2O3 into GaN to obtain Ga2O3 / GaN nanorods; Step 5: Encapsulate the Ga2O3 / GaN photoanode and the counter electrode, inject Na2SO4 electrolyte, and obtain a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods.

2. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 1, characterized in that: In step 1, the Ti wire substrate pretreatment specifically comprises: placing the Ti wire substrate in acetone, anhydrous ethanol, and deionized water in sequence, performing ultrasonic cleaning for 15 minutes, and drying.

3. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 1, characterized in that: In step 2, the specific method for preparing GaOOH nanorods on the Ti wire substrate by the hydrothermal method is as follows: the Ti wire substrate is placed in a 50 mL polytetrafluoroethylene-lined stainless steel autoclave, the precursor solution is added, the autoclave is sealed, and the autoclave is placed in a hydrothermal reactor for hydrothermal reaction, and then naturally cooled to room temperature.

4. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 3, characterized in that: The precursor solution is a gallium nitrate aqueous solution, and its preparation method is as follows: 4.992g of gallium nitrate is added to 50ml of deionized water, fully dissolved, and stirred for 20 minutes to obtain the gallium nitrate aqueous solution.

5. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 3, characterized in that: The conditions of the hydrothermal reaction are: heating to 150° C. in an oven, maintaining for 18 h, and then cooling to room temperature.

6. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 1, wherein: In step 3, the annealing treatment is specifically as follows: heating the slide rail furnace to 400° C., maintaining the temperature for 4 hours, and then cooling the furnace to room temperature to obtain α-Ga2O3 nanorods.

7. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 1, characterized in that: In step 4, the specific steps of ammoniation of the α-Ga2O3 nanorods are as follows: the annealed α-Ga2O3 nanorods are placed in a crucible, and the crucible is placed in a slide rail furnace together, the slide rail furnace is heated to 900°C, ammonia and argon are introduced at 30sccm and 20sccm respectively, and maintained for 10 minutes to obtain Ga2O3 / GaN nanorods.

8. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 1, wherein: In step 5, the packaging method is: the Ga2O3 / GaN photoanode, the counter electrode and the reference electrode are packaged relative to each other at a certain distance, and the electrolyte is injected.

9. The method for preparing a PEC-type linear ultraviolet detector based on Ga2O3 / GaN nanorods according to claim 8, characterized in that: The counter electrode is a Pt electrode, the reference electrode is a saturated calomel electrode; and the electrolyte is a 0.5M Na2SO4 aqueous solution.

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