A Ga-doped ZnO one-dimensional transparent conductive array, a preparation method thereof and a conductivity regulation method thereof

Abstract

The application discloses a Ga-doped ZnO one-dimensional transparent conductive array and a preparation method and a conductivity regulation method thereof, and comprises the following steps: preparing a ZnO film as a seed layer on a P-type silicon wafer substrate by using a magnetron sputtering film coating method; preparing an aqueous solution by using zinc nitrate hexahydrate, hexamethylenetetramine and gallium nitrate hydrate, wherein the molar concentration of the zinc nitrate hexahydrate and the gallium nitrate hydrate is 25 mmol / L in total, and the molar concentration of the hexamethylenetetramine is 25 mmol / L; mixing the two solutions to obtain a mixed solution, and controlling the pH value of the mixed solution to be between 7 and 9, so as to obtain a hydrothermal solution; introducing the hydrothermal solution into a high-pressure reaction kettle container, controlling the filling degree in the high-pressure reaction kettle container to be between 70% and 80%, and immersing the P-type silicon wafer substrate with the ZnO film downwards in the hydrothermal solution, so as to obtain the Ga-doped ZnO one-dimensional transparent conductive array; and regulating the conductivity of the Ga-doped ZnO one-dimensional transparent conductive array by changing the Ga doping ratio.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor optoelectronic device technology, specifically relating to a Ga-doped ZnO one-dimensional transparent conductive array and its preparation method and conductivity modulation method. Background Technology

[0002] One-dimensional (1D) nanostructures, especially nanowires, nanorods, and related structures, have gradually become key building blocks for next-generation nanodevices, thanks to their excellent aspect ratio and direct electron transport paths, resulting in superior charge collection efficiency. ZnO nanowire arrays stand out due to their unique combination of properties: a large specific surface area enhances light-matter interactions, a distinct C-axis crystal orientation enables directional carrier transport, and they are inexpensive to fabricate. However, the inherent limitations of ZnO, particularly its low native carrier concentration, poor electron mobility, and the excessively long axial carrier transport paths caused by traditional top-bottom electrode structures, hinder the realization of high-performance ultraviolet photodetectors.

[0003] Doping has proven to be a particularly effective and convenient method for improving the performance of ZnO. When dopant atoms replace Zn in the crystal lattice, they donate free electrons, thereby increasing carrier mobility. Among available dopants, Ga is particularly promising due to its ionic radius. and covalent radius With Zn (respectively) and ) are very close, which makes Ga 3+ It can replace Zn with minimal lattice distortion. 2+ Low-concentration Ga doping can increase carrier concentration and significantly reduce charge transfer resistance. Among these methods, hydrothermal doping offers significant advantages, including low cost, precise composition control, molecular-level precursor uniformity, and low-temperature crystallization. However, research on the stable and controllable growth of Ga-doped ZnO highly conductive 1D nanowires remains relatively limited.

[0004] The fabrication of Ga-doped ZnO one-dimensional transparent conductive arrays is an important research direction, aiming to simultaneously achieve high conductivity and high C-axis orientation. However, current fabrication techniques still face challenges in uniformity control, doping concentration regulation, and directional growth of the array structure. Therefore, developing an efficient, controllable, and easily scaled-up fabrication method is of great significance for the practical promotion and application of Ga-doped ZnO one-dimensional transparent conductive arrays. Summary of the Invention

[0005] Purpose of the invention: To address the limitations of current fabrication techniques in terms of uniformity control, doping concentration regulation, and directional growth of array structures, this invention proposes a Ga-doped ZnO one-dimensional transparent conductive array, its fabrication method, and its conductivity regulation method.

[0006] Technical solution: A method for fabricating a Ga-doped ZnO one-dimensional transparent conductive array, comprising the following steps:

[0007] Step 1: A ZnO film as a seed layer is prepared on a P-type silicon wafer substrate using magnetron sputtering.

[0008] Step 2: Prepare an aqueous solution using zinc nitrate hexahydrate, hexamethylenetetramine, and gallium nitrate hydrate, wherein the combined molar concentration of zinc nitrate hexahydrate and gallium nitrate hydrate is 25 mmol / L, and the molar concentration of hexamethylenetetramine is 25 mmol / L. Mix the two solutions to obtain a mixed solution, and control the pH value of the mixed solution between 7 and 9, which will be used as a hydrothermal solution.

[0009] Step 3: The hydrothermal solution is introduced into the high-pressure reactor container, and the filling degree of the high-pressure reactor container is controlled between 70% and 80%. The P-type silicon wafer substrate with ZnO film prepared in Step 1 is immersed in the hydrothermal solution with the film side facing down to obtain a Ga-doped ZnO one-dimensional transparent conductive array.

[0010] Furthermore, the thickness of the ZnO film is 30 nm to 50 nm.

[0011] Furthermore, the ratio of zinc nitrate hexahydrate to gallium nitrate hydrate is 99:1, 98.5:1.5, 98:2, 97:3, 96:4, 95:5, 90:10, 80:20, or 70:30.

[0012] This invention proposes a Ga-doped ZnO one-dimensional transparent conductive array, which is a conductive array prepared by the above-disclosed method for preparing a Ga-doped ZnO one-dimensional transparent conductive array.

[0013] Furthermore, the height of the Ga-doped ZnO one-dimensional transparent conductive array is 600 nm to 1.5 μm, and the diameter of a single element is 50 nm to 500 nm.

[0014] This invention discloses a method for controlling the conductivity of a Ga-doped ZnO one-dimensional transparent conductive array. By changing the proportion of Ga doping, the conductivity of the Ga-doped ZnO one-dimensional transparent conductive array can be controlled.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0016] (1) The conductivity of the Ga-doped ZnO nanoarray prepared by the method of the present invention is significantly improved, and the performance is optimized by adjusting the doping concentration;

[0017] (2) The Ga-doped ZnO nanoarrays prepared by the method of the present invention have high stability and oxidation resistance, and are suitable for harsh environments;

[0018] (3) The Ga-doped ZnO nanoarray prepared by the method of the present invention provides excellent anisotropic electron transport characteristics and higher specific surface area, thereby improving the efficiency of optoelectronic devices; at the same time, the preparation method of the present invention is relatively simple, suitable for large-scale production, and has cost advantages.

[0019] (4) The Ga-doped ZnO nanoarrays prepared by the method of the present invention can be widely used in photovoltaic cells, ultraviolet detectors and other fields, showing great application potential. Attached Figure Description

[0020] Figure 1 This is a SEM image of the 1% Ga-doped ZnO nanoarray in an embodiment of the present invention;

[0021] Figure 2 This is a SEM image of the 1.5% Ga-doped ZnO nanoarray in an embodiment of the present invention.

[0022] Figure 3 This is a SEM image of the 2% Ga-doped ZnO nanoarray in an embodiment of the present invention;

[0023] Figure 4 This is a SEM image of the 3% Ga-doped ZnO nanoarray in an embodiment of the present invention;

[0024] Figure 5 XRD patterns comparing Ga-doped ZnO nanoarrays and ZnO nanoarrays of various proportions in embodiments of the present invention;

[0025] Figure 6 This is a schematic diagram of the device structure for conductivity measurement in an embodiment of the present invention.

[0026] Figure 7 These are IV scan curves of various proportions of Ga-doped ZnO nanoarrays and ZnO nanoarrays in embodiments of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0028] Example 1:

[0029] This embodiment proposes a Ga-doped ZnO one-dimensional transparent conductive array, including a Ga-doped ZnO one-dimensional array and a silicon wafer with a ZnO seed layer. The Ga-doped ZnO one-dimensional array is grown on the surface of the silicon wafer with the ZnO seed layer by a hydrothermal method.

[0030] In this embodiment, the height of the obtained Ga-doped ZnO one-dimensional transparent conductive array is 600 nm to 1.5 μm, and the diameter of a single element is 50 nm to 500 nm.

[0031] The obtained Ga-doped ZnO one-dimensional transparent conductive array generates a corresponding current under a certain voltage; under the same voltage conditions, the current generated by the 1% Ga-doped ZnO one-dimensional transparent conductive array is 10% higher than that of the pure ZnO one-dimensional transparent conductive array. 5 ~10 6 High conductivity is an inherent property of Ga-doped ZnO one-dimensional transparent conductive arrays.

[0032] The above-mentioned Ga-doped ZnO one-dimensional transparent conductive array was prepared by the following hydrothermal method:

[0033] Step 1: A ZnO film is prepared on a P-type silicon substrate using magnetron sputtering as a seed layer for growing Ga-doped ZnO nanoarrays. The thickness of the seed layer is 30 nm to 50 nm.

[0034] Step 2: Preparation of the reaction aqueous solution: The aqueous solution was prepared from zinc nitrate hexahydrate (Zn(NO3)2·6H2O), hexamethylenetetramine ((CH2)6N4), and gallium nitrate hydrate (Ga(NO3)3·xH2O), wherein the combined molar concentration of zinc nitrate hexahydrate and gallium nitrate hydrate was 25 mmol / L, and the molar concentration of hexamethylenetetramine was 25 mmol / L. The two solutions were stirred at 25°C for 30 minutes, and then mixed and stirred at 25°C for another 30 minutes. The ratio of zinc nitrate hexahydrate to gallium nitrate hydrate was 99:1, 98.5:1.5, 98:2, 97:3, 96:4, 95:5, 90:10, 80:20, 70:30, etc.

[0035] Step 3: Prepare a mixed solution using ZnNO3·6H2O, Ga2(NO3)3·xH2O and (CH2)6N4, and control the pH of the mixed solution between 7 and 9 to serve as a hydrothermal solution.

[0036] Step 4: The hydrothermal solution is introduced into the high-pressure reactor container, and the filling degree of the high-pressure reactor container is controlled between 70% and 80%. Then, the silicon wafer with ZnO seed layer prepared in Step 1 is immersed face down in the hydrothermal solution. After that, the high-pressure reactor container is sealed and placed in a heat preservation box. The temperature is raised to 90°C and kept at that temperature for 6 hours. After the heat preservation is completed, it is rinsed with cold water and cooled to room temperature. The wafer is taken out, the surface of the wafer is cleaned with anhydrous ethanol and then dried with nitrogen gas to obtain a Ga-doped ZnO one-dimensional transparent conductive array.

[0037] By changing the Ga doping ratio, the conductivity of a one-dimensional transparent conductive array of Ga-doped ZnO can be controlled. The one-dimensional transparent conductive array of Ga-doped ZnO proposed in this embodiment has a simple structure, is easy to fabricate, and has excellent conductivity; this array has broad application prospects and huge market benefits in the fabrication of ultraviolet detectors and ultraviolet lasers.

[0038] Example 2:

[0039] Based on Example 1, this example proposes a method for fabricating a one-dimensional conductive array of 1% Ga-doped ZnO on a silicon substrate, specifically including:

[0040] A 30 nm thick undoped ZnO seed layer was grown on a P-type silicon substrate using magnetron sputtering. A 250 mL solution was prepared by mixing 1.8407 g of ZnNO3·6H2O and 0.016 g of Ga2(NO3)3·xH2O, and another 250 mL solution was prepared by mixing 0.8763 g of (CH2)6N4. The ratio of zinc nitrate hexahydrate to gallium nitrate hydrate in the mixed solution was 99:1. 30 mL of this solution was placed in a reaction vessel, and the silicon wafer with the seed layer was inverted within it. After hydrothermal treatment at 90 °C for 6 hours, a highly oriented Ga-doped ZnO array was obtained with a doping concentration of 1%. Figure 1 ).

[0041] Sample XRD ( Figure 5 The results show that the array has a highly preferred (002) orientation. Figure 1 The results showed that the 1% GaZnO array consisted of regular nanowires and also exhibited a high degree of preferred orientation. Ag electrodes were fabricated on the silicon wafer and on top of the array, respectively. Figure 6 Using a semiconductor parameter analyzer, a line scan from -5V to 5V was performed. Compared with an undoped ZnO array, the conductivity was improved by 10%. 5 times( Figure 7 ).

[0042] Example 3:

[0043] Based on Example 1, this example proposes a method for fabricating a one-dimensional conductive array of 1.5% Ga-doped ZnO on a silicon substrate, specifically including:

[0044] A 30 nm thick undoped ZnO seed layer was grown on a P-type silicon substrate using magnetron sputtering. A 200 mL solution was prepared from 1.4651 g of ZnNO3·6H2O and 0.0192 g of Ga2(NO3)3·xH2O, and another 200 mL solution was prepared from 0.701 g of (CH2)6N4. The ratio of zinc nitrate hexahydrate to gallium nitrate hydrate in the mixed solution was 98.5:1.5. 30 mL of this solution was placed in a reaction vessel, and the silicon wafer with the seed layer was inverted within it. After hydrothermal treatment at 90 °C for 6 hours, a highly oriented Ga-doped ZnO array with a doping concentration of 1.5% was obtained. Figure 2 ).

[0045] Sample XRD ( Figure 5 The results show that the array has a highly preferred (002) orientation. Figure 2 The results showed that the 1.5% GaZnO array consisted of regular nanowires and exhibited a high degree of preferred orientation. Ag electrodes were fabricated on the silicon wafer and on top of the array, respectively. Line scans from -5V to 5V were performed using a semiconductor parameter analyzer. Compared to the undoped ZnO array, the conductivity was improved by 10%. 4 times( Figure 7 ).

[0046] Example 4:

[0047] Based on Example 1, this example proposes a method for fabricating a one-dimensional conductive array of 2% Ga-doped ZnO on a silicon substrate, specifically including:

[0048] A 30 nm thick undoped ZnO seed layer was grown on a P-type silicon substrate using magnetron sputtering. A 100 mL solution was prepared from 0.7289 g of ZnNO3·6H2O and 0.0128 g of Ga2(NO3)3·xH2O, and another 100 mL solution was prepared from 0.3505 g of (CH2)6N4. The ratio of zinc nitrate hexahydrate to gallium nitrate hydrate in the mixed solution was 98:2. 30 mL of this solution was placed in a reaction vessel, and the silicon wafer with the seed layer was inverted within it. After hydrothermal treatment at 90 °C for 6 hours, a highly oriented Ga-doped ZnO array with a doping concentration of 2% was obtained. Figure 3 ).

[0049] Sample XRD ( Figure 5 The results show that the array has a highly preferred (002) orientation. Figure 3 The results showed that the 2% GaZnO array consisted of regular nanowires and exhibited a high degree of preferred orientation. Ag electrodes were constructed on the silicon wafer and on top of the array, respectively. Line scans from -5V to 5V were performed using a semiconductor parameter analyzer. Compared to the undoped ZnO array, the conductivity was improved. Figure 7 ).

[0050] Example 5:

[0051] Based on Example 1, this example proposes a method for fabricating a one-dimensional conductive array of 3% Ga-doped ZnO on a silicon substrate, specifically including:

[0052] A 30 nm thick undoped ZnO seed layer was grown on a P-type silicon substrate using magnetron sputtering. A 100 mL solution was prepared from 0.7214 g of ZnNO3·6H2O and 0.0192 g of Ga2(NO3)3·xH2O, and another 100 mL solution was prepared from 0.3505 g of (CH2)6N4. The ratio of zinc nitrate hexahydrate to gallium nitrate hydrate in the mixed solution was 97:3. 30 mL of this solution was placed in a reaction vessel, and the silicon wafer with the seed layer was inverted within it. After hydrothermal treatment at 90 °C for 6 hours, a highly oriented Ga-doped ZnO array with a doping concentration of 3% was obtained. Figure 4 ).

[0053] Sample XRD ( Figure 5 The results show that the array has a highly preferred (002) orientation. Figure 4 The results showed that the 3% GaZnO array consisted of regular nanowires and exhibited a high degree of preferred orientation. Ag electrodes were constructed on the silicon wafer and on top of the array, respectively. Line scans from -5V to 5V were performed using a semiconductor parameter analyzer. Compared to the undoped ZnO array, the conductivity was improved. Figure 7 ).

Claims

1. A method for fabricating a Ga-doped ZnO one-dimensional transparent conductive array, characterized in that: Includes the following steps: Step 1: A ZnO film as a seed layer is prepared on a P-type silicon substrate using magnetron sputtering; the thickness of the ZnO film is 30nm~50nm. Step 2: A hydrothermal solution is prepared using zinc nitrate hexahydrate, hexamethylenetetramine, and gallium nitrate hydrate according to the following steps: Solution 1 was prepared using zinc nitrate hexahydrate and gallium nitrate hydrate; wherein the total molar concentration of zinc nitrate hexahydrate and gallium nitrate hydrate in solution 1 was 25 mmol / L, and the ratio of zinc nitrate hexahydrate to gallium nitrate hydrate was 99:1, 98.5:1.5, 98:2, 97:3, 96:4, 95:5, 90:10, 80:20 or 70:30; Solution II was prepared using hexamethylenetetramine; wherein the molar concentration of hexamethylenetetramine in solution II was 25 mmol / L. The first solution and the second solution are mixed to obtain a mixed solution, and the pH value of the mixed solution is controlled between 7 and 9, which is used as a hydrothermal solution; Step 3: The hydrothermal solution is introduced into the high-pressure reactor container, and the filling degree of the high-pressure reactor container is controlled between 70% and 80%. The P-type silicon wafer substrate with ZnO film prepared in Step 1 is immersed in the hydrothermal solution with the film side facing down. Then, the high-pressure reactor container is sealed and placed in a heat preservation box. The temperature is raised to 90°C and kept at that temperature for 6 hours. After the heat preservation is completed, it is rinsed with cold water and cooled to room temperature. The silicon wafer is taken out, the surface of the silicon wafer is cleaned with anhydrous ethanol and then dried with nitrogen gas to obtain a Ga-doped ZnO one-dimensional transparent conductive array.

2. A Ga-doped ZnO one-dimensional transparent conductive array, characterized in that: The conductive array is prepared by the method for preparing a Ga-doped ZnO one-dimensional transparent conductive array as described in claim 1.

3. The Ga-doped ZnO one-dimensional transparent conductive array according to claim 2, characterized in that: The height of the Ga-doped ZnO one-dimensional transparent conductive array is 600 nm to 1.5 μm, and the diameter of a single element is 50 nm to 500 nm.

4. A method for controlling the conductivity of a Ga-doped ZnO one-dimensional transparent conductive array, characterized in that: The conductivity of a Ga-doped ZnO one-dimensional transparent conductive array can be modulated by changing the Ga doping ratio. The Ga-doped ZnO one-dimensional transparent conductive array is a conductive array prepared by the method described in claim 1.

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