CdTe thin film photovoltaic cell based on composite window layer and preparation method of CdTe thin film photovoltaic cell

Abstract

The invention discloses a CdTe thin film photovoltaic cell based on a composite window layer and a preparation method thereof, and belongs to the technical field of photovoltaic devices, the CdTe thin film photovoltaic cell based on the composite window layer comprises a transparent conductive substrate, the composite window layer, a CdTe absorption layer, a ZnTe interface modification layer and a metal back electrode in sequence from bottom to top; the composite window layer is formed by compounding a CdS layer, a CdSeO4 layer and a ZnS layer. The CdS / CdSeO4 / ZnS multi-layer composite window layer is introduced to realize the synergistic effect of triple functions of energy level matching, ion blocking and light transmission, so that the photoelectric property and the stability of the CdTe film photovoltaic cell are improved.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic device technology, specifically relating to a CdTe thin-film photovoltaic cell based on a composite window layer and its preparation method. Background Technology

[0002] CdTe thin-film photovoltaic cells employ a structure where light enters through a transparent conductive substrate, reducing light absorption loss and increasing short-circuit current density. Existing CdTe thin-film photovoltaic cells often use a single-layer CdS or CdS / CdSe dual-window layer structure for the window layer, which suffers from low energy level matching, weak ion diffusion blocking ability, and numerous interface defects. This limits the improvement of open-circuit voltage and fill factor, making it difficult to meet commercialization requirements in terms of long-term stability. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a CdTe thin-film photovoltaic cell based on a composite window layer and its preparation method. This application achieves a synergistic effect of "energy level matching-ion blocking-light transmission" by introducing a CdS / CdSeO4 / ZnS multilayer composite window layer, thereby improving the photoelectric performance and stability of the CdTe thin-film photovoltaic cell.

[0004] One objective of this invention is to provide a CdTe thin-film photovoltaic cell based on a composite window layer. The CdTe thin-film photovoltaic cell comprises, from bottom to top, a transparent conductive substrate, a composite window layer, a CdTe absorber layer, a ZnTe interface modification layer, and a metal back electrode. The composite window layer is composed of a CdS layer, a CdSeO4 layer, and a ZnS layer. The CdS layer is located above the transparent conductive substrate, the CdSeO4 layer is located between the CdS layer and the ZnS layer, and the ZnS layer is located below the CdTe absorber layer.

[0005] This invention employs a CdS / CdSeO4 / ZnS composite structure as the composite window layer for CdTe thin-film photovoltaic cells to achieve a synergistic effect of "energy level matching, ion blocking, and light transmission," thereby improving the photoelectric performance and stability of CdTe thin-film photovoltaic cells. Specifically, the CdS layer is located above and directly contacts the transparent conductive substrate, with a band gap of 2.4~2.6 eV, exhibiting excellent light transmittance and conductivity, thus reducing the contact barrier between the transparent conductive substrate and the window layer and minimizing carrier recombination at the interface. The CdSeO4 layer serves as an intermediate energy level matching layer, with a band gap of 2.7~2.9 eV, facilitating a step transition between the CdS and ZnS layers, constructing an efficient carrier transport channel, and simultaneously improving visible light transmittance. The ZnS layer is located below and directly contacts the CdTe absorption layer, with a density ≥98% and a Cd²⁺ diffusion coefficient ≤3×10⁻⁶. -11With a speed of cm² / s and a high bandgap of 3.5~3.7eV, it can reduce light absorption loss and block Cd²⁺ from migrating to the window layer, thereby improving the battery's environmental safety and long-term stability.

[0006] Furthermore, the thickness of the CdS layer is 35~55nm; the thickness of the CdSeO4 layer is 20~30nm; and the thickness of the ZnS layer is 5~8nm.

[0007] Furthermore, the transparent conductive substrate is any one of FTO / ITO conductive glass or ITO flexible PET substrate, with a sheet resistance ≤10Ω / □ and a light transmittance ≥88%; the CdTe absorption layer has a thickness of 1.8~2.2μm; the ZnTe interface modification layer has a thickness of 5~8nm; and the metal back electrode has a thickness of 200~300nm, which is any one of Cu / Au composite electrode or Mo electrode.

[0008] A second objective of this invention is to provide a method for preparing the above-mentioned CdTe thin-film photovoltaic cell based on a composite window layer, comprising the following steps: The transparent conductive substrate is pretreated to obtain the pretreated transparent conductive substrate; The pretreated transparent conductive substrate is immersed in a CdS precursor solution and subjected to a chemical bath deposition reaction to form a CdS layer. CdSeO4 material is deposited on the CdS layer to form a CdSeO4 layer; ZnS material is deposited on the CdSeO4 layer to form a ZnS layer; An absorber layer material is deposited on the ZnS layer, and then annealed in an inert atmosphere to form a CdTe absorber layer. An interface modification layer material is deposited on the CdTe absorber layer to form a ZnTe interface modification layer; A metal back electrode material is deposited on the ZnTe interface modification layer to form a metal back electrode, thereby obtaining a CdTe thin-film photovoltaic cell based on a composite window layer.

[0009] Furthermore, the CdS precursor solution comprises 0.03 mol / L cadmium nitrate and 0.08 mol / L thiourea; the chemical bath deposition reaction is carried out at a temperature of 60-70°C for 20-25 minutes.

[0010] Furthermore, the deposition method used to form the CdTe absorber layer is near-space sublimation or electrospray deposition; the annealing temperature for the annealing treatment is 380~400℃, and the annealing time is 20~25min.

[0011] Furthermore, the deposition method used to form the CdSeO4 layer, ZnS layer, and ZnTe interface modification layer was magnetron sputtering.

[0012] Furthermore, the deposition method used to form the metal back electrode is either thermal evaporation or magnetron sputtering.

[0013] Furthermore, the method for preparing CdTe thin-film photovoltaic cells based on the composite window layer also includes post-processing and encapsulation. The post-processing and encapsulation method is as follows: the obtained CdTe thin-film photovoltaic cells based on the composite window layer are placed in an annealing furnace at 110~120℃ in a nitrogen atmosphere and kept at that temperature for 10~15 minutes. After cooling to room temperature, they are diced to form independent cell units for encapsulation.

[0014] Furthermore, the encapsulation temperature is 120~140℃ and the pressure is 0.08~0.12MPa.

[0015] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention uses a CdS layer, a CdSeO4 layer, and a ZnS layer to form a CdS / CdSeO4 / ZnS multilayer composite window layer. This composite window layer, together with a transparent conductive substrate, a CdTe absorption layer, a ZnTe interface modification layer, and a metal back electrode, forms a CdTe thin-film photovoltaic cell. The CdS layer has excellent light transmittance and conductivity, thereby reducing the contact barrier between the transparent conductive substrate and the window layer and reducing carrier interface recombination. The CdSeO4 layer serves as an intermediate energy level matching layer, realizing the energy level transition between the CdS layer and the ZnS layer, constructing an efficient carrier transport channel, and simultaneously improving visible light transmittance. The ZnS layer is in direct contact with the CdTe absorption layer, with a density ≥98%. 2+ Diffusion coefficient ≤ 3 × 10 -11 cm 2 / s, which can reduce light absorption loss and block Cd 2+ By migrating to the window layer, the combination of these three elements achieves a synergistic effect of "energy level matching, ion blocking, and light transmission," thereby improving the photoelectric performance and stability of CdTe thin-film photovoltaic cells.

[0016] (2) The medium-low temperature preparation process of this invention is more suitable for flexible substrates, which effectively expands the application of CdTe thin film photovoltaic cells in wearable devices, flexible photovoltaic modules and other fields; at the same time, the strong ion blocking ability of the ZnS layer combined with the separate treatment process of cadmium-containing waste liquid can greatly reduce the risk of cadmium pollution and meet the requirements of green production; at the same time, the preparation process of this invention is compatible with existing CdTe production lines, without the need for large-scale equipment modification, which greatly reduces the cost of large-scale industrialization. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the structure of the CdTe thin-film photovoltaic cell based on the composite window layer in Embodiment 1 of the present invention.

[0018] Figure 2 This is a schematic diagram showing the efficiency degradation of CdTe thin-film photovoltaic cells based on composite window layers after 1000h of damp heat aging in Embodiment 1 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings.

[0020] Unless otherwise specified, all reagents used in this invention are commercially available, and all methods used are conventional techniques in the art.

[0021] Example 1 A CdTe thin-film photovoltaic cell based on a composite window layer is shown in the schematic diagram below. Figure 1 As shown, the photovoltaic cell consists of a transparent conductive substrate, a composite window layer, a CdTe absorber layer, a ZnTe interface modification layer, and a metal back electrode, from bottom to top. The composite window layer is composed of a CdS layer, a CdSeO4 layer, and a ZnS layer. The CdS layer is located above the transparent conductive substrate, the CdSeO4 layer is located between the CdS layer and the ZnS layer, and the ZnS layer is located below the CdTe absorber layer.

[0022] A method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer includes the following steps: Step S1: Pretreatment of the transparent conductive substrate A 100mm×100mm FTO conductive glass (sheet resistance of 8Ω / □) was ultrasonically cleaned sequentially with deionized water, acetone, and anhydrous ethanol for 18 minutes. After being dried with nitrogen, it was placed in an argon plasma cleaner with a power of 140W for 6 minutes to remove organic impurities and oxide layers from the surface of the conductive glass, resulting in a pretreated transparent conductive substrate.

[0023] Step S2: Preparation of CdS / CdSeO4 / ZnS composite window layer Step S21: Preparation of CdS layer Add 0.2 mol / L ammonia to a mixed solution of 65.4 mL of 0.03 mol / L cadmium nitrate and 50 mL of 0.08 mol / L thiourea to adjust the pH of the solution to 10.5 to obtain a CdS precursor solution. Immerse the pretreated transparent conductive substrate in the CdS precursor solution and react in a constant temperature water bath at 65℃ for 20 min to form a CdS layer with a thickness of 45 nm.

[0024] Step S22, Preparation of CdSeO4 A 25 nm thick CdSeO4 thin film was deposited on a CdS layer using reactive magnetron sputtering to form the CdSeO4 layer. The reactive magnetron sputtering method used a CdSe target as the sputtering source, a mixture of argon and oxygen (7% oxygen by volume) as the sputtering gas, a sputtering power of 100 W, and a sputtering vacuum of 5 × 10⁻⁶. -4 Pa, deposition temperature is 160℃, deposition rate is 0.08nm / s.

[0025] Step S23: Preparation of ZnS layer A 6 nm thick ZnS thin film was deposited on a CdSeO4 layer using radio frequency magnetron sputtering to form the ZnS layer. The radio frequency magnetron sputtering method used a 99.9% pure ZnS target as the sputtering source, pure argon gas as the sputtering gas, a sputtering power of 90 W, and a sputtering vacuum of 4 × 10⁻⁶. -4 Pa, deposition temperature is 160℃, deposition rate is 0.05nm / s.

[0026] Step S3: Preparation of CdTe absorber layer A CdTe thin film was deposited on a ZnS layer using a near-space sublimation method. Then, a 0.25 mol / L CdCl2 ethanol solution was sprayed onto the CdTe film. Finally, the film was annealed at 390 °C for 25 min under a nitrogen atmosphere to form a 3 μm thick CdTe absorber layer. The near-space sublimation method used CdTe powder as the source material, with a source temperature of 580 °C, a substrate temperature of 320 °C, and a vacuum degree of 5 × 10⁻⁶. -2 Pa.

[0027] Step S4: Preparation of ZnTe interface modification layer A 20 nm thick ZnTe thin film was deposited on the CdTe absorber layer using radio frequency magnetron sputtering to form a ZnTe interface modification layer. The radio frequency magnetron sputtering method used a 99.9% pure ZnTe target as the sputtering source, pure argon gas as the sputtering gas, a sputtering power of 100 W, and a sputtering vacuum of 4 × 10⁻⁶. -4 Pa, deposition temperature is room temperature, and deposition rate is 0.05 nm / s.

[0028] Step S5: Fabrication of the metal back electrode A 200 nm thick Cu thin film and a 30 nm thick Au thin film were sequentially deposited on a ZnTe interface modification layer using a thermal evaporation method to form a Cu / Au composite metal back electrode, resulting in a CdTe thin-film photovoltaic cell based on a composite window layer. The thermal evaporation method used 99.999% pure Cu and Au wires as evaporation materials, which were loaded into a tungsten boat evaporation source and evaporated at a pressure of 5 × 10⁻⁶.-3 Under Pa conditions, Cu was first deposited at a deposition rate of 0.5 nm / s to form a Cu film with a thickness of 200 nm; then Au was deposited at a deposition rate of 0.2 nm / s to form an Au film with a thickness of 30 nm.

[0029] Step S6, Post-processing and Packaging The CdTe thin-film photovoltaic cells based on the composite window layer obtained above were placed in an annealing furnace at 115°C under a nitrogen atmosphere and kept at that temperature for 12 minutes. After cooling to room temperature, they were laser-scribed to form independent cell units. Finally, they were encapsulated using a structure of "front glass - encapsulation film - cell unit - encapsulation film - back glass" at a temperature of 130°C and a pressure of 0.1 MPa.

[0030] The performance results of the CdTe thin-film photovoltaic cell based on the composite window layer obtained in this embodiment are as follows: short-circuit current J sc 27.0 mA / cm 2 Open circuit voltage V oc The voltage is 0.85V, the fill factor FF is 75.5%, and the photoelectric conversion efficiency is 16.5%; after 1000h of damp heat aging, the photoelectric conversion efficiency is 15.9%, and the photoelectric conversion efficiency decreases by 3.64%.

[0031] Example 2 A method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer includes the following steps: Step S1: Pretreatment of transparent conductive substrate A 100μm thick ITO flexible PET substrate (sheet resistance of 10Ω / □) was ultrasonically cleaned sequentially with deionized water, acetone, and anhydrous ethanol for 15 minutes. After being dried with nitrogen, it was placed in an argon plasma cleaner with a power of 140W for 5 minutes to remove organic impurities and oxide layers from the conductive glass surface, resulting in a pretreated transparent conductive substrate.

[0032] Step S2: Preparation of CdS / CdSeO4 / ZnS composite window layer Step S21: Preparation of CdS layer Add 0.2 mol / L ammonia to a mixed solution of 65.4 mL of 0.03 mol / L cadmium nitrate and 50 mL of 0.08 mol / L thiourea to adjust the pH of the solution to 10.5 to obtain a CdS precursor solution. Immerse the pretreated transparent conductive substrate in the CdS precursor solution and react in a constant temperature water bath at 65℃ for 20 min to form a CdS layer with a thickness of 45 nm.

[0033] Step S22, Preparation of CdSeO4 A 25 nm thick CdSeO4 thin film was deposited on a CdS layer using reactive magnetron sputtering to form the CdSeO4 layer. The reactive magnetron sputtering method used a CdSe target as the sputtering source, a mixture of argon and oxygen (7% oxygen by volume) as the sputtering gas, a sputtering power of 100 W, and a sputtering vacuum of 5 × 10⁻⁶. -4 Pa, deposition temperature is 150℃, deposition rate is 0.08nm / s.

[0034] Step S23: Preparation of ZnS layer A 6 nm thick ZnS thin film was deposited on a CdSeO4 layer using radio frequency magnetron sputtering to form the ZnS layer. The radio frequency magnetron sputtering method used a 99.9% pure ZnS target as the sputtering source, pure argon gas as the sputtering gas, a sputtering power of 90 W, and a sputtering vacuum of 4 × 10⁻⁶. -4 Pa, deposition temperature is 150℃, deposition rate is 0.05nm / s.

[0035] Step S3: Preparation of CdTe absorber layer A CdTe thin film was deposited on a ZnS layer using electrospray deposition. Then, a 0.1 mol / L CdCl2 ethanol solution was sprayed onto the CdTe film. The film was preheated at 120°C for 5 min under a dry air atmosphere at a pressure of 1 atm, and finally annealed at 380°C for 30 min under a nitrogen atmosphere to form a CdTe absorption layer with a thickness of 2 μm. The source material used in the electrospray deposition method was a 0.1 mol / L CdTe precursor solution (CdCl2 ethanol solution), the spray voltage was 15 kV, and the substrate temperature was 300°C.

[0036] Step S4: Preparation of ZnTe interface modification layer A 20 nm thick ZnTe thin film was deposited on the CdTe absorber layer using radio frequency magnetron sputtering to form a ZnTe interface modification layer. The radio frequency magnetron sputtering method used a 99.9% pure ZnTe target as the sputtering source, pure argon gas as the sputtering gas, a sputtering power of 100 W, and a sputtering vacuum of 4 × 10⁻⁶. -4 Pa, deposition temperature is room temperature, and deposition rate is 0.05 nm / s.

[0037] Step S5: Fabrication of the metal back electrode A 280 nm thick Mo thin film was sequentially deposited on a ZnTe interface modification layer using a thermal evaporation method to form a Mo metal back electrode, resulting in a CdTe thin-film photovoltaic cell based on a composite window layer. The thermal evaporation method used Mo filaments with a purity greater than 99.95% as the evaporation material, placed in a molybdenum boat evaporation source, and operated at a temperature of 75 °C and a pressure of 8 × 10⁻⁶. -4Under the condition of Pa, a Mo film with a deposition rate of 0.5 nm / s and a thickness of 280 nm was deposited.

[0038] Step S6, Post-processing and Packaging The CdTe thin-film photovoltaic cells based on the composite window layer obtained above were placed in an annealing furnace at 110°C under a nitrogen atmosphere and kept at that temperature for 10 minutes. After cooling to room temperature, they were laser-scribed to form independent cell units. Finally, they were encapsulated in a “PET-film-aluminum foil” structure at a temperature of 120°C and a pressure of 0.08MPa.

[0039] The performance results of the CdTe thin-film photovoltaic cell based on the composite window layer obtained in this embodiment are as follows: short-circuit current J sc 26.8 mA / cm 2 Open circuit voltage V oc The voltage is 0.84V, the fill factor FF is 76.6%, the photoelectric conversion efficiency is 15.8%, and the photoelectric conversion efficiency is 15.52% after 1000h of damp heat aging, with a photoelectric conversion efficiency decay of 1.8%.

[0040] Comparative Example 1 In this comparative example, a CdTe thin-film photovoltaic cell based on a composite window layer and its preparation method are exactly the same as those in Example 1, except that the composite window layer is different. The composite window layer in this comparative example is CdS / CdSeO4, and the preparation method of this composite layer is exactly the same as the preparation of the CdS layer and the preparation of CdSeO4 in Example 1.

[0041] The performance results of the CdTe thin-film photovoltaic cell based on the composite window layer obtained in this comparative example are as follows: short-circuit current J sc 26.3 mA / cm 2 Open circuit voltage V oc The voltage was 0.81V, the fill factor FF was 74.2%, and the photoelectric conversion efficiency was 16.0%; after 1000h of damp heat aging, the photoelectric conversion efficiency was 15.03%, and the photoelectric conversion efficiency decreased by 6.06%.

[0042] Comparative Example 2 In this comparative example, a CdTe thin-film photovoltaic cell based on a composite window layer and its preparation method are exactly the same as those in Example 1, except that the composite window layer is different. The composite window layer in this comparative example is CdS / ZnS, and the preparation method of this composite layer is exactly the same as the preparation of the CdS layer and the preparation of ZnS in Example 1.

[0043] The performance results of the CdTe thin-film photovoltaic cell based on the composite window layer obtained in this comparative example are as follows: short-circuit current J sc 26.5 mA / cm 2 Open circuit voltage Voc The voltage is 0.79V, the fill factor FF is 73.9%, and the photoelectric conversion efficiency is 15.9%; after 1000h of damp heat aging, the photoelectric conversion efficiency is 14.83%, and the photoelectric conversion efficiency decreases by 6.73%.

[0044] Comparative Example 3 In this comparative example, a CdTe thin-film photovoltaic cell based on a composite window layer and its preparation method are exactly the same as those in Example 1, except that the composite window layer is different. The composite window layer in this comparative example is CdSeO4 / ZnS, and the preparation method of this composite layer is exactly the same as the preparation of CdSeO4 and ZnS layer in Example 1.

[0045] The performance results of the CdTe thin-film photovoltaic cell based on the composite window layer obtained in this comparative example are as follows: short-circuit current J sc 25.4 mA / cm 2 Open circuit voltage V oc The voltage was 0.81V, the fill factor FF was 75.1%, and the photoelectric conversion efficiency was 14.72%; after 1000h of damp heat aging, the photoelectric conversion efficiency was 13.69%, and the photoelectric conversion efficiency decreased by 7.0%.

[0046] Depend on Figure 2 It can be seen that the performance of CdTe thin-film photovoltaic cells based on CdSeO4 / ZnS dual-window layers, CdS / ZnS dual-window layers, and CdS / CdSeO4 dual-window layers is significantly weaker than that of CdTe thin-film photovoltaic cells based on CdS / CdSeO4 / ZnS composite window layers. This truly achieves the synergistic effect of the triple functions of "energy level matching-ion blocking-light transmission", effectively improving the photoelectric performance and stability of CdTe thin-film photovoltaic cells.

[0047] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the inventive concept of this invention, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.

[0048] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If such modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A CdTe thin-film photovoltaic cell based on a composite window layer, characterized in that, The CdTe thin-film photovoltaic cell comprises, from bottom to top, a transparent conductive substrate, a composite window layer, a CdTe absorber layer, a ZnTe interface modification layer, and a metal back electrode; the composite window layer is composed of a CdS layer, a CdSeO4 layer, and a ZnS layer; the CdS layer is located above the transparent conductive substrate, the CdSeO4 layer is located between the CdS layer and the ZnS layer, and the ZnS layer is located below the CdTe absorber layer.

2. The CdTe thin-film photovoltaic cell based on a composite window layer according to claim 1, characterized in that, The thickness of the CdS layer is 35~55nm; the thickness of the CdSeO4 layer is 20~30nm; and the thickness of the ZnS layer is 5~8nm.

3. The CdTe thin-film photovoltaic cell based on a composite window layer according to claim 1, characterized in that, The transparent conductive substrate is any one of FTO / ITO conductive glass or ITO flexible PET substrate, with a sheet resistance ≤10Ω / □ and a light transmittance ≥88%; the CdTe absorption layer has a thickness of 1.8~2.2μm; the ZnTe interface modification layer has a thickness of 5~8nm; the metal back electrode has a thickness of 200~300nm, and is any one of Cu / Au composite electrode or Mo electrode.

4. A method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer as described in any one of claims 1 to 3, characterized in that, Includes the following steps: The transparent conductive substrate is pretreated to obtain the pretreated transparent conductive substrate; The pretreated transparent conductive substrate is immersed in a CdS precursor solution and subjected to a chemical bath deposition reaction to form a CdS layer. CdSeO4 material is deposited on the CdS layer to form a CdSeO4 layer; ZnS material is deposited on the CdSeO4 layer to form a ZnS layer; An absorber layer material is deposited on the ZnS layer, and then annealed in an inert atmosphere to form a CdTe absorber layer. An interface modification layer material is deposited on the CdTe absorber layer to form a ZnTe interface modification layer; A metal back electrode material is deposited on the ZnTe interface modification layer to form a metal back electrode, thereby obtaining a CdTe thin-film photovoltaic cell based on a composite window layer.

5. The method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer according to claim 4, characterized in that, The CdS precursor solution comprises 0.03 mol / L cadmium nitrate and 0.08 mol / L thiourea; the chemical bath deposition reaction is carried out at a temperature of 60-70°C for 20-25 minutes.

6. The method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer according to claim 4, characterized in that, The deposition method used to form the CdTe absorber layer is near-space sublimation or electrospray deposition; the annealing temperature for the annealing treatment is 380~400℃, and the annealing time is 20~25min; the deposition method used to form the CdSeO4 layer, ZnS layer and ZnTe interface modification layer is magnetron sputtering; the deposition method used to form the metal back electrode is thermal evaporation or magnetron sputtering.

7. The method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer according to claim 4, characterized in that, It also includes post-processing and packaging, and the post-processing and packaging method is as follows: the obtained CdTe thin film photovoltaic cell based on the composite window layer is placed in an annealing furnace at 110~120℃ in a nitrogen atmosphere and kept at that temperature for 10~15 minutes. After cooling to room temperature, it is diced to form independent cell units for packaging.

8. The method for preparing a CdTe thin-film photovoltaic cell based on a composite window layer according to claim 7, characterized in that, The encapsulation temperature is 120~140℃ and the pressure is 0.08~0.12MPa.

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