A CuCrO2 / GaON heterojunction solar-blind ultraviolet detector and its preparation method

Abstract

The present invention discloses a CuCrO2 / GaON heterostructure solar-blind ultraviolet detector and its preparation method. The detector comprises, in sequence, a quartz substrate; a GaON thin film located above the quartz substrate and subjected to in-situ plasma treatment; a CuCrO2 layer located above the GaON film; a first test electrode located above the GaON film; and a second test electrode located above the CuCrO2 layer. The GaON film and the CuCrO2 layer form a CuCrO2 / GaON heterojunction, creating an internal electric field to separate photogenerated carriers. The prepared CuCrO2 / GaON heterostructure solar-blind ultraviolet detector exhibits stable performance, high sensitivity, and fast response speed, and can effectively detect solar-blind ultraviolet light with a wavelength less than 280 nm.

Description

Technical Field

[0001] The invention relates to a CuCrO2 / GaON heterojunction solar-blind ultraviolet detector and a preparation method thereof, belonging to the technical field of photoelectric detection. Background Art

[0002] Solar-blind ultraviolet light generally refers to electromagnetic radiation in the 200-280nm wavelength band. Due to the ozone layer's strong absorption of this wavelength band, the ultraviolet light in this band that reaches the near-Earth surface is very weak, providing a natural low-background window for detecting solar-blind ultraviolet signals. A solar-blind ultraviolet detector is a UV detector that has a distinct light response to this wavelength band. Solar-blind UV detectors have a high signal-to-noise ratio and a low false alarm rate, and possess significant advantages in detecting weak signals. In recent years, solar-blind detectors have garnered significant attention due to their significant application value in both civilian and military fields. UV detectors have broad application prospects in space communications, military missile warning, ozone layer monitoring, non-line-of-sight secure optical communications, high-voltage electrical detection, flame detection, and biochemical testing.

[0003] GaON is an emerging ultra-wide bandgap semiconductor material. Due to its excellent physical properties, it is considered an ideal material for making solar-blind ultraviolet light detectors. Self-powered detectors based on the photovoltaic effect can operate without an external power supply and exhibit excellent light detection performance. They can meet the needs of modern society, show great application potential, and have become a research hotspot. Therefore, selecting a suitable material to construct a heterojunction with GaON has become the first choice for preparing high-performance GaON self-powered detectors. Inorganic semiconductors have the characteristics of high carrier concentration and stable performance, and are suitable for constructing heterojunctions with GaON to prepare solar-blind detectors. CuCrO2 is a hole transport material that is easy to synthesize, high in purity, and has good solubility and stability. It has been widely used in transparent conductive electrodes, solar cells, and photocatalysis.

[0004] In order to solve the technical difficulties of improving the photoelectric performance of detectors, many companies and research institutes have conducted extensive research, but have not achieved the expected results. Therefore, how to solve the above problems is of great significance for the application of GaON solar-blind ultraviolet detectors in the field of solar-blind ultraviolet detection. Summary of the Invention

[0005] The present invention aims to provide a CuCrO2 / GaON heterojunction solar-blind UV detector and its fabrication method, achieving high sensitivity and speed with low dark current using a relatively simple fabrication process. The detector utilizes a quartz substrate and GaON as the light detection material. The GaON film is treated in situ with plasma, and a CuCrO2 layer is deposited on the GaON film surface using spin coating, resulting in a high-performance, high-sensitivity, and low-cost detector.

[0006] The technical solution for achieving the purpose of the present invention is:

[0007] A solar-blind ultraviolet detector with a CuCrO2 / GaON heterostructure and a preparation method thereof, wherein the detector comprises, in sequence, a quartz substrate, a GaON thin film located above the quartz substrate and subjected to in-situ plasma treatment; a CuCrO2 layer located above the GaON thin film; a first test electrode located above the GaON thin film; and a second test electrode located above the CuCrO2 layer; wherein the GaON thin film and the CuCrO2 layer form a CuCrO2 / GaON heterojunction, constituting an internal electric field to separate photogenerated carriers.

[0008] The solar-blind ultraviolet detector with GaON heterostructure and the preparation method thereof of the present invention comprises the following steps:

[0009] Step 1: Pre-treat the quartz substrate (1) by ultrasonically cleaning it with acetone, anhydrous ethanol, and deionized water for 15 to 30 minutes, and then drying it with high-purity nitrogen. Place the treated quartz substrate (1) in a deposition chamber and grow a GaON film (2) using plasma-enhanced chemical vapor deposition (PECVD).

[0010] Step 2: The CuCrO2 layer (3) is synthesized by a hydrothermal method and uniformly distributed on the GaON film (2) by a spin coating method, thereby obtaining a CuCrO2 / GaON heterojunction on the quartz substrate (1).

[0011] Step three: using a magnetron sputtering method to evaporate a first test electrode (4) on the CuCrO2 layer (3), and to evaporate a second test electrode (5) on the GaON film (2).

[0012] Preferably, the GaON film (2) in step 1 is grown and deposited by PECVD, using high-purity metallic gallium (99.999%) and high-purity O2 (99.999%) as precursors and high-purity Ar (99.999%) as carrier gas.

[0013] Preferably, the GaON film (2) in step 1 is deposited by PECVD growth, with a growth temperature of 700-1000° C., a growth pressure of 0.1-100 Pa, a radio frequency power of 50-200 W, a growth time of 1-3 h, and the GaON film (2) needs to be plasma treated.

[0014] Preferably, the GaON film (2) in step 1 needs to be subjected to plasma treatment, the plasma source is one or more of nitrogen, oxygen and argon, the treatment time is 1 to 30 minutes, and the treatment power is 5 to 30W.

[0015] Preferably, the CuCrO2 in step 2 is synthesized by a hydrothermal method, with a growth temperature of 150 to 300°C and a growth time of 12 to 72 hours.

[0016] Preferably, the CuCrO2 in step 2 is evenly coated on the GaON film (2) by spin coating to form a CuCrO2 layer, with the spin parameters being: a speed of 1000-5000 rpm and a time of 10-120 seconds.

[0017] Preferably, the first test electrode (4) and the second test electrode (5) in step three are both metal electrodes, and the thickness of the metal electrode layer is 10 to 100 nm.

[0018] More preferably, the metal electrode material is one or more of Au, Ag, Ti, Ni and Al.

[0019] The beneficial effects of the present invention are:

[0020] This invention uses quartz as a substrate and GaON as a light detection material. The GaON thin film is treated in situ using plasma, and a CuCrO2 layer is deposited on the GaON film surface using spin coating, resulting in a high-performance, highly sensitive, and low-cost detector. Experiments have shown that the CuCrO2 / GaON heterojunction UV detector prepared using this method can effectively detect UV light with high sensitivity and performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0022] Figure 1 This is a structural diagram of the CuCrO2 / GaON heterostructure solar-blind ultraviolet detector described in the present invention, 1-quartz substrate, 2-GaON film, 3-CuCrO2 layer, 4-first test electrode, 5-second test electrode.

[0023] Figure 2 This is a cross-sectional SEM image of the CuCrO2 / GaON heterojunction solar-blind detector on the quartz substrate described in the present invention.

[0024] Figure 3 This is the IV curve of the CuCrO2 / GaON heterojunction solar-blind ultraviolet detector on the quartz substrate of the present invention.

[0025] Figure 4It is the response time of the CuCrO2 / GaON heterojunction solar-blind ultraviolet detector on the quartz substrate of the present invention at 0V. DETAILED DESCRIPTION

[0026] A CuCrO2 / GaON heterostructure solar-blind ultraviolet detector and a preparation method thereof are characterized by comprising a quartz substrate (1), a GaON film (2) located above the substrate (1), a CuCrO2 layer (3) above the GaON film (2), a first test electrode (4) located on the CuCrO2 layer (3), and a second test electrode (5) located on one side of and above the GaON film (2), wherein the GaON film (2) and the CuCrO2 layer (3) form a CuCrO2 / GaON heterojunction to constitute an internal electric field.

[0027] Step 1: Pre-treat the quartz substrate (1) by ultrasonically cleaning it with acetone, anhydrous ethanol, and deionized water for 15 to 30 minutes, and then drying it with high-purity nitrogen. Place the treated quartz substrate (1) in a deposition chamber and grow a GaON film (2) using plasma-enhanced chemical vapor deposition (PECVD).

[0028] Step 2: The CuCrO2 layer (3) is synthesized by a hydrothermal method and uniformly distributed on the GaON film (2) by a spin coating method, thereby obtaining a GaON / CuCrO2 heterojunction on the quartz substrate (1).

[0029] Step three: using a magnetron sputtering method to evaporate a first test electrode (4) on the CuCrO2 layer (3), and to evaporate a second test electrode (5) on the GaON film (2).

[0030] Furthermore, the GaON film (2) in step 1 is grown and deposited by PECVD, with high-purity metallic gallium (99.999%) and high-purity O2 (99.999%) as precursors and high-purity Ar (99.999%) as carrier gas.

[0031] Furthermore, the GaON film (2) in step 1 is grown and deposited by PECVD, with a growth temperature of 700-1000° C., a growth pressure of 0.1-100 Pa, a radio frequency power of 50-200 W, a growth time of 1-3 h, and the GaON film (2) needs to be plasma treated.

[0032] Furthermore, the GaON film (2) in step 1 needs to be subjected to plasma treatment, the plasma source is one or more of nitrogen, oxygen and argon, the treatment time is 1 to 30 minutes, and the treatment power is 5 to 30W.

[0033] Furthermore, the CuCrO2 in step 2 is synthesized by a hydrothermal method, with a growth temperature of 150 to 300° C. and a growth time of 12 to 72 hours.

[0034] Furthermore, the CuCrO2 in the step 2 is evenly coated on the GaON film (2) by spin coating to form a CuCrO2 layer, with the spin parameters being: a speed of 1000-5000 rpm and a time of 10-120 seconds.

[0035] Furthermore, the first test electrode (4) and the second test electrode (5) in step three are both metal electrodes, and the thickness of the metal electrode layer is 10 to 100 nm.

[0036] Furthermore, the metal electrode material is one or more of Au, Ag, Ti, Ni and Al.

[0037] The present invention is described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several variations and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0038] To further illustrate the present invention, a CuCrO2 / GaON heterostructure day-blind ultraviolet detector and a preparation method thereof provided by the present invention are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present invention.

[0039] Example 1

[0040] An 80mm×80mm×0.2mm quartz substrate was rinsed in acetone, ethanol, and deionized water for 10 minutes each, then rinsed again with deionized water and finally dried with dry nitrogen. The substrate was then placed in a quartz reaction tube with a gallium source placed 7cm from the substrate. Ar as carrier and shield gas, and O2 and N2 as reaction gases were passed through the quartz reaction tube. The temperature was set at 900°C, and the RF power was set to 150W. The growth time was 100 minutes to deposit a GaON thin film on the substrate. The resulting GaON film was treated with an in-situ nitrogen plasma treatment at a power of 50W, a nitrogen flow rate of 100 sccm, and a treatment time of 30 minutes. CuCrO2 was then synthesized hydrothermally by dissolving 15mmol of Cr(NO3)3·9H2O and 15mmol of Cu(NO3)2·3H2O in 70mL of deionized water, adding 5.0g of NaOH, and magnetically stirring. The solution was then poured into a 100mL polytetrafluoroethylene autoclave and grown at 240°C for 60h. The obtained CuCrO2 was collected and washed 5 times with diluted hydrochloric acid, ethanol and deionized water respectively to obtain pure CuCrO2. 10mg of CuCrO2 nanoparticles were then dispersed in 1mL of isopropanol solution. 50μl of the above solution was taken out and spin-coated on the surface of the GaON epitaxial film grown by PECVD. The spin coating speed was 3000rpm and the spin coating time was 60s. Ti / Au composite electrodes were evaporated on the CuCrO2 layer and GaON film respectively by magnetron sputtering as the first test electrode and the second test electrode.

[0041] Obviously, the above embodiments are merely illustrative examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will recognize that any modifications, equivalent substitutions, or improvements based on the above description and within the methods and principles of the present invention are intended to be within the scope of protection of the present invention. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A CuCrO2 / GaON heterostructure solar-blind ultraviolet detector, characterized in that: The detector comprises a quartz substrate (1), a GaON thin film (2), a CuCrO2 layer (3), a first test electrode (4), and a second test electrode (5); A GaON film (2) located above the quartz substrate (1), a CuCrO2 layer (3) above the GaON film (2), a first test electrode (4) located on the CuCrO2 layer (3), and a second test electrode (5) located on one side of and above the GaON film (2); the GaON film (2) and the CuCrO2 layer (3) form a CuCrO2 / GaON heterojunction to constitute an internal electric field.

2. The CuCrO2 / GaON-based solar-blind ultraviolet detector according to claim 1, characterized in that: The detector uses GaON thin film as the light detection material to detect solar-blind ultraviolet light with a wavelength less than 280 nm.

3. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 1 or 2, characterized in that , the specific preparation steps are: Step 1: pre-treating the quartz substrate (1), ultrasonically cleaning it with acetone, anhydrous ethanol and deionized water for 15 to 30 minutes in sequence, and drying it with high-purity nitrogen after cleaning; placing the treated quartz substrate (1) in a deposition chamber and growing a GaON film (2) using plasma enhanced chemical vapor deposition (PECVD); Step 2: The CuCrO2 layer (3) is synthesized by a hydrothermal method and uniformly distributed on the GaON film (2) by a spin coating method to obtain a CuCrO2 / GaON heterojunction on the quartz substrate (1); Step three: using a magnetron sputtering method to evaporate a first test electrode (4) on the CuCrO2 layer (3), and to evaporate a second test electrode (5) on the GaON film (2).

4. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The GaON film (2) is grown and deposited by PECVD, using 99.999% high-purity metallic gallium and 99.999% high-purity O2 as precursors and 99.999% high-purity Ar as a carrier gas.

5. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The GaON film (2) is grown and deposited by PECVD, with a growth temperature of 700-1000°C, a growth pressure of 0.1-100 Pa, a radio frequency power of 50-200 W, a growth time of 1-3 h, and the GaON film (2) needs to be plasma treated.

6. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The GaON film (2) needs to be subjected to plasma treatment, the plasma source is one or more of nitrogen, oxygen and argon, the treatment time is 1 to 30 minutes, and the treatment power is 5 to 30 W.

7. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The CuCrO2 is synthesized by a hydrothermal method, with a growth temperature of 150 to 300° C. and a growth time of 12 to 72 hours.

8. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The CuCrO2 is evenly coated on the GaON film (2) by spin coating to form a CuCrO2 layer, with the spin parameters being: a spin speed of 1000-5000 rpm and a spin time of 10-120 seconds.

9. The method for preparing a solar-blind ultraviolet detector of a CuCrO2 / GaON heterostructure according to claim 3, characterized in that: The first test electrode (4) and the second test electrode (5) are both metal electrodes, the thickness of the metal electrodes is 10 to 100 nm, and the metal electrode material is one or more of Au, Ag, Ti, Ni and Al.

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