A copper indium gallium selenide thin-film solar cell and its preparation method

Abstract

The copper indium gallium selenide (CIGS) thin-film solar cell and its fabrication method provided in this application include a substrate, a Mo back electrode, a CIGS absorber layer, and a Zn electrode stacked sequentially. x In 1‑x The S-buffer layer, transparent conductive layer, and Ni-Al gate electrode, wherein the Zn x In 1‑x The S-buffer layer is deposited by mid-frequency magnetron sputtering. The copper indium gallium selenide (CIGS) thin-film solar cell and its fabrication method provided in this application deposit Zn by mid-frequency magnetron sputtering. x In 1‑x S(0

Description

Technical Field

[0001] This application relates to the field of thin-film solar cell technology, and in particular to a copper indium gallium selenide thin-film solar cell and its preparation method. Background Technology

[0002] Global warming and the energy crisis caused by environmental pollution are pressing issues that humanity urgently needs to address. The development of renewable energy, especially solar energy, has become a current trend in the energy industry. Cadmium-containing copper indium gallium selenide (CIGS) solar cells are among the most efficient thin-film solar cells, characterized by low manufacturing costs, high photoelectric conversion efficiency, and no light-induced degradation. A typical structure includes: a glass substrate, a molybdenum back electrode, a copper indium gallium selenide absorber layer, a cadmium sulfide buffer layer, an intrinsic zinc oxide (i-ZnO) window layer, and an aluminum-doped zinc oxide (AZO) transparent conductive layer. In 2019, a novel small-sized flexible CIGS solar cell developed through a collaboration between MiaSolé Hi-Tech Corp. (USA) and Solliance Solar Research (Europe) achieved a conversion efficiency of 23%. In 2021, Avancis, a subsidiary of China National Building Materials Group, produced a large-area CIGS solar cell module with a photoelectric conversion efficiency of 19.64%, demonstrating significant research and application potential.

[0003] Most current CIGS thin-film solar cells use a water bath method (CBD) to deposit a CdS buffer layer on the absorber layer. However, due to the limitations of CdS, this method is less efficient. 2+CdS is a heavy metal, a toxic element harmful to both humans and the environment, and can cause harm during production, use, and recycling. CdS has a narrow band gap, exhibiting strong absorption in short wavelengths below the blue light spectrum in sunlight, reducing the utilization of sunlight by CIGS. CdS buffer layers are mostly prepared using wet processes, while other layers in thin-film solar cells are typically prepared using dry processes in a vacuum. Therefore, production lines employing a hybrid dry and wet process increase process complexity, making the dry preparation of cadmium-free buffer layers crucial. Cd-free buffer layers need to possess properties similar to CdS while also being environmentally friendly. In recent years, substances such as ZnSe, ZnS, ZnO, and In₂Se₃ have attracted attention. Since Cd and Zn both belong to Group IIB, their chemical properties are more similar, and their corresponding sulfide, ZnS, also exhibits very similar characteristics to CdS. The ZnS bandgap of 3.7 eV is wider than that of CdS (2.4 eV), making it a better choice as a buffer layer to reduce photon energy loss in the blue light region. Furthermore, indium doping increases the donor concentration of ZnS, which is beneficial for generating stronger band bending and a built-in electric field at the heterojunction interface, thus promoting carrier transport. However, if ZnS or In₂Se₃ is used alone as a buffer layer, the conversion efficiency of the resulting thin-film solar cells consistently falls short of that obtained using CdS as a buffer layer. This is because the bandgap and lattice constant matching between the buffer layer material and the P-type light-absorbing layer is not ideal, resulting in higher interface state defects. Summary of the Invention

[0004] Therefore, it is necessary to provide a copper indium gallium selenide thin-film solar cell and its preparation method that not only overcomes the drawbacks of heavy metal cadmium in posing a threat to human and environmental health and safety, but also improves production efficiency, in order to address the shortcomings of existing technologies.

[0005] To solve the above problems, this application adopts the following technical solution:

[0006] One objective of this application is to provide a copper indium gallium selenide (CIGS) thin-film solar cell, comprising a substrate, a Mo back electrode, a CIGS absorber layer, and a Zn electrode stacked sequentially. x In 1-x The Zn buffer layer, transparent conductive layer, and Ni-Al gate electrode are described. x In 1-x The S-buffer layer was deposited by mid-frequency magnetron sputtering. <x<1。

[0007] In some embodiments, the substrate comprises soda-lime glass, stainless steel foil, or titanium foil.

[0008] In some embodiments, the Mo back electrode comprises a bilayer Mo film, wherein the thickness of the first Mo film is 250–300 nm and the thickness of the second Mo film is 900–1000 nm.

[0009] In some embodiments, the thickness of the CIGS absorber layer is 1.8–3 μm.

[0010] In some embodiments, the Zn x In 1-x The thickness of the S buffer layer is 50–200 nm.

[0011] In some embodiments, the transparent conductive layer comprises 50-100 nm i-ZnO and 100-300 nm AZO.

[0012] In some embodiments, the Ni-Al gate electrode includes a Ni electrode and an Al electrode deposited on the Ni electrode, wherein the Ni electrode has a thickness of 100–180 nm and the Al electrode has a thickness of 9500–11000 nm.

[0013] The second objective of this application is to provide a method for fabricating the aforementioned copper indium gallium selenide thin-film solar cell, comprising the following steps:

[0014] The Mo back electrode is deposited on the substrate;

[0015] The CIGS absorber layer is deposited on the Mo back electrode;

[0016] The Zn was deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x S buffer layer, 0 <x<1;

[0017] In the Zn x In 1-x The transparent conductive layer is prepared on the S buffer layer;

[0018] A Ni-Al gate electrode is deposited on the transparent conductive layer.

[0019] In some embodiments, the step of depositing the Mo back electrode on the substrate specifically includes: depositing the Mo back electrode on the substrate by DC magnetron sputtering.

[0020] In some embodiments, the step of depositing the CIGS absorber layer on the Mo back electrode specifically includes the following steps: preparing the CIGS absorber layer using a three-step co-evaporation method and depositing the CIGS absorber layer on the Mo back electrode.

[0021] In some embodiments, a CIGS absorber layer is prepared using a three-step co-evaporation method and deposited on the Mo back electrode, specifically including:

[0022] In, Ga, and Se are co-evaporated to prepare (In,Ga)2Se3 on the back electrode Mo, while NaF is co-evaporated to obtain a precursor film.

[0023] Cu and Se are co-evaporated to react Cu with the precursor film to obtain a CIGS film with a Cu-rich surface, wherein the excess Cu content is between 5% and 15%.

[0024] In, Ga, and Se are co-distilled again to obtain the CIGS absorber layer.

[0025] In some embodiments, the Zn is deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x The steps involved in the S-buffer layer process specifically include the following:

[0026] The obtained substrate coated with the CIGS absorber layer was placed in a mid-frequency magnetron sputtering chamber and sputtered at a temperature of 100–350°C for 5–15 minutes in an environment filled with H2S gas at a flow rate of 250–400 sccm, to obtain the Zn. x In 1-x S-buffer layer.

[0027] In some embodiments, the Zn x In 1-x The step of preparing the transparent conductive layer on the S buffer layer specifically includes the following steps: depositing the Zn... x In 1-x The substrate with the S-buffer layer was placed in the radio frequency magnetron sputtering chamber and filled with argon and oxygen at a flow rate ratio of 10:1. x In 1-x The surface of the S buffer layer is sequentially sputtered with 50-100 nm i-ZnO and 100-300 nm AZO.

[0028] In some embodiments, the step of depositing a Ni-Al gate electrode on the transparent conductive layer specifically includes the following steps: depositing a Ni electrode on the transparent conductive layer using electron beam evaporation, and then depositing an Al electrode on the Ni electrode.

[0029] The present application adopts the above technical solution, and its beneficial effects are as follows:

[0030] The copper indium gallium selenide (CIGS) thin-film solar cell and its fabrication method provided in this application include a substrate, a Mo back electrode, a CIGS absorber layer, and a Zn electrode stacked sequentially.x In 1-x an S buffer layer, a transparent conductive layer, and a Ni - Al gate electrode, wherein the Zn x In 1-x The S buffer layer is deposited by medium - frequency magnetron sputtering. The copper indium gallium selenide thin - film solar cell and its preparation method provided in this application deposit Zn x In 1-x S(0 < x < 1) buffer layer, which not only overcomes the drawback of the heavy metal cadmium harming human and environmental health and safety, but also the indium doping increases the donor concentration of ZnS, promoting carrier transport. In addition, the medium - frequency magnetron sputtering process effectively improves the consistency of the preparation process of the copper indium gallium selenide thin - film solar cell module, making it more convenient for production on a production line, forming at one time, reducing the pollution suffered when the sample is transferred between different processes, and improving production efficiency and the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for describing the embodiments of the present application or the prior art. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0032] Figure 1 is a schematic structural diagram of the copper indium gallium selenide thin - film solar cell provided by the embodiment of the present application.

[0033] Figure 2 is a step - flow chart of the preparation method of the copper indium gallium selenide thin - film solar cell provided by the embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following details the embodiments of the present application. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present application, and should not be construed as a limitation of the present application.

[0035] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "upper", "lower", "horizontal", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0036] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "plural" means two or more unless specifically defined otherwise.

[0037] To make the objectives, technical solutions and advantages of this application more clear and understandable, the following further details this application in conjunction with the accompanying drawings and embodiments.

[0038] Please refer to Figure 1 , which is a schematic structural diagram of a copper indium gallium selenide thin-film solar cell provided by an embodiment of this application, including a substrate 110, a Mo back electrode 120, a CIGS absorption layer 130, Zn x In 1-x S buffer layer 140, a transparent conductive layer 150, and a Ni-Al grid electrode 160 that are sequentially stacked. The Zn x In 1-x S buffer layer 140 is deposited by medium-frequency magnetron sputtering, where 0 < x < 1. The following details the specific implementation of each layer.

[0039] In some embodiments, the substrate 110 includes soda-lime glass, stainless steel foil, or titanium foil. In some embodiments, the Mo back electrode 12 includes a double-layer Mo thin film. The thickness of the first-layer Mo thin film in the double-layer Mo thin film is 250 - 300 nm, and the thickness of the second-layer Mo thin film is between 900 - 1000 nm. The finally obtained Mo back electrode layer not only has a tight bond with the substrate but also has good electrical conductivity.

[0040] In some embodiments, the thickness of the CIGS absorption layer 130 is 1.8 - 3 μm, the bandgap is about 1.5 eV, and the sunlight absorption rate exceeds 93%.

[0041] In some embodiments, the Zn x In 1-x S buffer layer 140 has a thickness of 50 - 200 nm and a bandgap greater than 2.4 eV, improving the device's response in the short wavelength band.

[0042] In some embodiments, the transparent conductive layer 150 includes 50 - 100 nm of i-ZnO and 100 - 300 nm of AZO, having high electrical conductivity and high light transmittance, and the average transmittance in the visible light region is not less than 85%.

[0043] In some of these embodiments, the Ni-Al gate electrode 170 includes a Ni electrode and an Al electrode deposited on the Ni electrode. The Ni electrode has a thickness of 100 - 180 nm, and the Al electrode has a thickness of 9500 - 11000 nm. It has advantages such as high electrical conductivity and tight bonding with the transparent conductive layer, providing a smooth and stable channel for current output.

[0044] It can be understood that medium-frequency magnetron sputtering has advantages such as high target utilization rate and stable operation. Its power supply voltage waveform is an AC sputtering mode of a symmetric square wave or a sine wave. Due to the use of a pair of twin dual targets, it can effectively increase the film deposition rate, and reduce or avoid target poisoning phenomena. During the life cycle of the target, it can achieve long-term stable operation and can be used for reactive sputtering to prepare compound films.

[0045] The copper indium gallium selenide thin-film solar cell provided by this application deposits Zn x In 1-x S(0 < x < 1) buffer layer. It not only overcomes the drawback of heavy metal cadmium harming human and environmental health and safety, but indium doping also increases the donor concentration of ZnS, promoting carrier transport. In addition, the use of the medium-frequency magnetron sputtering process effectively improves the consistency of the preparation process of the copper indium gallium selenide thin-film solar cell module, making it more convenient for production line production, one-time forming, reducing the pollution suffered by the sample during transfer between different processes, and improving production efficiency and the yield rate of good products.

[0046] Please refer to Figure 2 , which is the step flowchart of the preparation method of the copper indium gallium selenide thin-film solar cell provided by the embodiment of this application, including the following steps S110 to step S150. The implementation methods of each step are described in detail below.

[0047] Step S110: Deposit the Mo back electrode on the substrate.

[0048] It can be understood that before depositing the Mo back electrode on the soda-lime glass substrate, there is also a step of substrate cleaning to remove surface contaminants and dust.

[0049] Specifically, first rinse the substrate with deionized water, and use a semiconductor cleaning agent for auxiliary cleaning during this process. The cleaning duration is greater than 10 min. After cleaning, place the substrate in an ultrasonic cleaning machine; after cleaning with an ultrasonic cleaner for 40 min, rinse it with deionized water again. This process does not require the use of a semiconductor cleaning agent, and the cleaning duration is 10 min; then in a dust-free shed, use high-pressure pure nitrogen to remove the residual water stains on the substrate surface.

[0050] In some of these embodiments, in the step of depositing the Mo back electrode on the substrate, specifically include: depositing the Mo back electrode on the substrate by DC magnetron sputtering.

[0051] Specifically, a clean substrate is placed inside a DC magnetron sputtering chamber and the vacuum level is evacuated to a specified pressure before sputtering. The filling gas is argon, and the sputtering temperature is 150 degrees Celsius. The first Mo film has a thickness of 250–300 nm, and the second Mo film has a thickness of approximately 900–1000 nm.

[0052] Step S120: Deposit the CIGS absorber layer on the Mo back electrode.

[0053] In some embodiments, the step of depositing the CIGS absorber layer on the Mo back electrode specifically includes the following steps: preparing the CIGS absorber layer using a three-step co-evaporation method and depositing the CIGS absorber layer on the Mo back electrode.

[0054] Specifically, a CIGS absorber layer is prepared and deposited on the Mo back electrode using a three-step co-evaporation method, which includes:

[0055] In, Ga, and Se are co-evaporated to prepare (In,Ga)2Se3 on the back electrode Mo, while NaF is co-evaporated to obtain a precursor film.

[0056] Cu and Se are co-evaporated to react Cu with the precursor film, resulting in a Cu-rich CIGS film with an excess of 5%-15%. This Cu enrichment process is a crucial step in film growth, promoting grain growth and allowing initially fine grains to recrystallize, ultimately yielding larger grains.

[0057] In, Ga, and Se are co-distilled again to obtain the CIGS absorber layer.

[0058] It is understood that this embodiment uses an improved three-step co-evaporation process to deposit the CIGS absorber layer. This process incorporates additional copper-rich phase deposition after the second step, enabling the low-temperature growth of large CIGS grains with good crystallinity even without post-deposition alkali metal treatment. The efficiency of the copper indium gallium selenide thin-film solar cell deposited at 460°C is comparable to that deposited at a high temperature of 540°C. This solves the problems of poor crystallinity, excessively small grain size, and increased recombination probability of photogenerated carriers caused by excessively low substrate temperature, which lead to reduced photoelectric conversion efficiency.

[0059] Step S130: Deposit the Zn on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x S buffer layer, 0 <x<1。

[0060] In some embodiments, the Zn is deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x The steps involved in the S-buffer layer process specifically include the following:

[0061] The obtained substrate coated with the CIGS absorber layer was placed in a mid-frequency magnetron sputtering chamber and sputtered at a temperature of 100–350°C for 5–15 minutes in an environment filled with H2S gas at a flow rate of 250–400 sccm, to obtain the Zn. x In 1-x S-buffer layer.

[0062] Step S140: In the Zn x In 1-x The transparent conductive layer is prepared on the S buffer layer.

[0063] In some embodiments, the Zn x In 1-x The step of preparing the transparent conductive layer on the S buffer layer specifically includes the following steps: depositing the Zn... x In 1-x The substrate with the S-buffer layer was placed in the radio frequency magnetron sputtering chamber and filled with argon and oxygen at a flow rate ratio of 10:1. x In 1-x The surface of the S buffer layer is sequentially sputtered with 50-100 nm i-ZnO and 100-300 nm AZO.

[0064] Step S150: Deposit a Ni-Al gate electrode on the transparent conductive layer.

[0065] In some embodiments, the step of depositing a Ni-Al gate electrode on the transparent conductive layer specifically includes the following steps: depositing a Ni electrode on the transparent conductive layer using electron beam evaporation, and then depositing an Al electrode on the Ni electrode.

[0066] The method for preparing copper indium gallium selenide thin-film solar cells provided in this application

[0067] The copper indium gallium selenide (CIGS) thin-film solar cell and its fabrication method provided in this application utilize a mid-frequency magnetron sputtering method to deposit Zn. x In 1-xThe S(0 < x < 1) buffer layer not only overcomes the drawbacks of heavy metal cadmium harming human and environmental health and safety, but indium doping also increases the donor concentration of ZnS, promoting carrier transport. In addition, the use of the medium-frequency magnetron sputtering process effectively improves the consistency of the preparation process of copper indium gallium selenide thin-film solar cell modules, making it more convenient for production on a production line, forming in one step, reducing the contamination suffered by samples during transfer between different processes, and improving production efficiency and the yield rate.

[0068] The above technical solutions of the present application will be described in detail below in conjunction with specific embodiments.

[0069] Example 1

[0070] Step 1: Clean the substrate.

[0071] Remove the organic pollutants and dust on the surface. First, rinse the substrate with deionized water. During this process, a semiconductor cleaning agent is used for auxiliary cleaning, and the cleaning duration is greater than 10 minutes. After cleaning, place the substrate in an ultrasonic cleaning machine; after cleaning with an ultrasonic cleaner for 40 minutes, rinse it with deionized water again. A semiconductor cleaning agent is not required during this process, and the cleaning duration is 10 minutes; then, in a dust-free booth, use high-pressure pure nitrogen to remove the residual water stains on the surface of the substrate;

[0072] Step 2: Prepare the Mo back electrode.

[0073] Place the clean substrate inside the DC magnetron sputtering chamber and pump the vacuum to the specified air pressure before preparing for sputtering. The filling gas is argon, and the sputtering temperature is 150 degrees Celsius; when preparing the first layer of Mo film, the sputtering power is 600 W, the argon is 400 sccm, and the sputtering thickness is about 300 nm. When preparing the second layer of Mo film, the sputtering power is 3 KW, the argon is 100 sccm, and the sputtering thickness is about 1000 nm;

[0074] Step 3: Prepare the CIGS absorption layer.

[0075] Place the substrate coated with the Mo back electrode layer obtained in Step 2 into the MBE chamber. After pumping the vacuum to the specified air pressure, use the three-step co-evaporation process to deposit the CIGS absorption layer on the back electrode, with a thickness of about 2 μm.

[0076] Step 4: Prepare the Zn x In 1-x S(0 < x < 1) buffer layer.

[0077] Put the sample coated with the CIGS absorption layer obtained in Step 3 into the medium-frequency magnetron sputtering chamber. The filling gas is H2S, with a flow rate of 250 - 400 sccm, and the substrate temperature is 100 - 350 °C. First, pre-sputter for 10 min to remove the contaminants on the target surface, and then sputter the sample for 5 - 15 min to obtain a ZnxIn1-xS (0 < x < 1) buffer layer with a thickness of 50 - 100 nm.

[0078] Step 5: Prepare the transparent conductive layer.

[0079] Put the sample obtained in Step 4 into the radio-frequency magnetron sputtering chamber, and fill it with argon and oxygen with a flow rate ratio of 10:1. Sputter 50 nm of i-ZnO and 200 nm of AZO successively on the surface of the Zn x In 1-x S (0 < x < 1) buffer layer.

[0080] Step 6: Prepare the gate.

[0081] Deposit 150 nm of Ni and 10000 nm of Al on the AZO surface of the sample obtained in Step 5 by thermal evaporation as the cathode of the CIGS solar cell.

[0082] In the above embodiments of the present application, the Zn x In 1-x S (0 < x < 1) buffer layer is deposited by medium-frequency magnetron sputtering method, which not only overcomes the disadvantages of heavy metal cadmium harming human and environmental health and safety, but also the indium doping increases the donor concentration of ZnS and promotes carrier transport. In addition, the medium-frequency magnetron sputtering process effectively improves the consistency of the preparation process of copper indium gallium selenide thin-film solar cell modules, is more convenient for production line production, forms in one step, reduces the pollution suffered by the sample during transfer between different processes, and improves production efficiency and yield.

[0083] It can be understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0084] The above is only the preferred embodiment of the present application, and only the technical principle of the present application is specifically described. These descriptions are only for explaining the principle of the present application and cannot be interpreted as any limitation to the protection scope of the present application. Based on this explanation, any modification, equivalent replacement, and improvement made within the spirit and principle of the present application, and other specific embodiments that can be联想到 by those skilled in the art without creative labor should be included in the protection scope of the present application.

Claims

1. A copper indium gallium selenide thin-film solar cell, characterized in that, Includes a substrate, a Mo back electrode, a CIGS absorber layer, and a Zn layer stacked sequentially. x In 1-x The Zn buffer layer, transparent conductive layer, and Ni-Al gate electrode are described. x In 1-x The S-buffer layer was deposited by mid-frequency magnetron sputtering. <x<1; The Zn x In 1-x The thickness of the S buffer layer is 50~200 nm; The Mo back electrode comprises a double-layer Mo film, wherein the thickness of the first Mo film is 250~300nm and the thickness of the second Mo film is 900~1000nm. The thickness of the CIGS absorber layer is 1.8~3μm; The transparent conductive layer comprises 50-100nm i-ZnO and 100-300nm AZO; The Ni-Al gate electrode includes a Ni electrode and an Al electrode deposited on the Ni electrode. The thickness of the Ni electrode is 100~180nm, and the thickness of the Al electrode is 9500~11000nm. The method for preparing the copper indium gallium selenide thin-film solar cell includes the following steps: The Mo back electrode is deposited on the substrate; The CIGS absorber layer is deposited on the Mo back electrode; The Zn was deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x S buffer layer, 0 <x<1; In the Zn x In 1-x The transparent conductive layer is prepared on the S buffer layer; A Ni-Al gate electrode is deposited on the transparent conductive layer; The Zn was deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x The steps involved in the S-buffer layer process specifically include the following: The obtained substrate coated with the CIGS absorber layer was placed in a mid-frequency magnetron sputtering chamber and sputtered at a temperature of 100-350℃ for 5-15 minutes in an environment filled with H2S gas at a flow rate of 250-400 sccm, to obtain the Zn. x In 1-x S-buffer layer; The step of depositing the CIGS absorber layer on the Mo back electrode specifically includes the following steps: preparing the CIGS absorber layer using a three-step co-evaporation method and depositing the CIGS absorber layer on the Mo back electrode; The CIGS absorber layer is prepared by a three-step co-evaporation method and deposited on the Mo back electrode, specifically including: In, Ga, and Se are co-evaporated to prepare (In,Ga)2Se3 on the back electrode Mo, while NaF is co-evaporated to obtain a precursor film. Cu and Se are co-evaporated to react Cu with the precursor film to obtain a CIGS film with a Cu-rich surface, wherein the excess of Cu is between 5% and 15%. In, Ga, and Se are co-distilled again to obtain the CIGS absorber layer; In the Zn x In 1-x The step of preparing the transparent conductive layer on the S buffer layer specifically includes the following steps: depositing the Zn... x In 1-x The substrate with the S-buffer layer was placed in the radio frequency magnetron sputtering chamber and filled with argon and oxygen at a flow rate ratio of 10:

1. x In 1-x The surface of the S buffer layer is sequentially sputtered with 50~100nm i-ZnO and 100~300nm AZO.

2. A method for preparing a copper indium gallium selenide thin-film solar cell as described in claim 1, characterized in that, Includes the following steps: The Mo back electrode is deposited on the substrate; The CIGS absorber layer is deposited on the Mo back electrode; The Zn was deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x S buffer layer, 0 <x<1; In the Zn x In 1-x The transparent conductive layer is prepared on the S buffer layer; A Ni-Al gate electrode is deposited on the transparent conductive layer; The Zn was deposited on the CIGS absorber layer by mid-frequency magnetron sputtering. x In 1-x The steps involved in the S-buffer layer process specifically include the following: The obtained substrate coated with the CIGS absorber layer was placed in a mid-frequency magnetron sputtering chamber and sputtered at a temperature of 100-350℃ for 5-15 minutes in an environment filled with H2S gas at a flow rate of 250-400 sccm, to obtain the Zn. x In 1-x S-buffer layer; The step of depositing the CIGS absorber layer on the Mo back electrode specifically includes the following steps: preparing the CIGS absorber layer using a three-step co-evaporation method and depositing the CIGS absorber layer on the Mo back electrode; The CIGS absorber layer is prepared by a three-step co-evaporation method and deposited on the Mo back electrode, specifically including: In, Ga, and Se are co-evaporated to prepare (In,Ga)2Se3 on the back electrode Mo, while NaF is co-evaporated to obtain a precursor film. Cu and Se are co-evaporated to react Cu with the precursor film to obtain a CIGS film with a Cu-rich surface, wherein the excess of Cu is between 5% and 15%. In, Ga, and Se are co-distilled again to obtain the CIGS absorber layer; In the Zn x In 1-x The step of preparing the transparent conductive layer on the S buffer layer specifically includes the following steps: depositing the Zn... x In 1-x The substrate with the S-buffer layer was placed in the radio frequency magnetron sputtering chamber and filled with argon and oxygen at a flow rate ratio of 10:

1. x In 1-x The surface of the S buffer layer is sequentially sputtered with 50~100nm i-ZnO and 100~300nm AZO.

3. The method for preparing a copper indium gallium selenide thin-film solar cell as described in claim 2, characterized in that, The step of depositing the Mo back electrode on the substrate specifically includes: depositing the Mo back electrode on the substrate by DC magnetron sputtering.

4. The method for preparing a copper indium gallium selenide thin-film solar cell as described in claim 2, characterized in that, The step of depositing a Ni-Al gate electrode on the transparent conductive layer specifically includes the following steps: depositing a Ni electrode on the transparent conductive layer by electron beam evaporation, and then depositing an Al electrode on the Ni electrode.

Images