Cu2ZnSnS4 thin film solar cell device with top lining structure
By employing a top-substrate structure, the CZTS thin-film solar cell device utilizes materials such as a highly conductive top electrode, a high-transmittance window layer, and an inorganic hole transport layer, simplifying the fabrication process, improving photoelectric conversion efficiency and material utilization, solving the complexity and cost issues of traditional substrate structures, and enhancing cell stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-18
- Publication Date
- 2026-03-24
AI Technical Summary
Traditional CZTS thin-film solar cell devices use a substrate structure, which leads to high fabrication complexity, high cost, low light utilization, and low photoelectric conversion efficiency. Furthermore, the selection and preparation of substrate materials increase production difficulty and cost.
The device employs a top-substrate structure, with the following components from top to bottom: top electrode, window layer, hole transport layer, buffer layer, absorption layer, and back electrode. A highly conductive metal or metal alloy is used as the top electrode, a high-transmittance material as the window layer, an inorganic material as the hole transport layer, a non-toxic semiconductor material as the buffer layer, a Cu2ZnSnS4 thin film as the absorption layer, and a conductive oxide as the substrate. This simplifies the fabrication process and improves light utilization.
It improves photoelectric conversion efficiency, simplifies the preparation process, reduces production costs, enhances material utilization and battery stability, and provides a new direction for the development of CZTS thin-film solar cells.
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Figure CN224037749U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the field of new energy technology, in particular to a Cu2ZnSnS4 (CZTS) thin film solar cell device with a top backing structure. BACKGROUND
[0002] Under the background of global energy crisis and increasingly serious environmental pollution, the development and utilization of clean energy have become the focus of global attention. As a clean energy technology with broad application prospects, thin film solar cells are highly valued due to their low cost, easy mass production and flexible application in various scenarios. As a new type of quaternary compound semiconductor material, Cu2ZnSnS4 (CZTS) is widely considered as a potential next-generation photovoltaic material due to its non-toxicity, abundant raw materials, band gap close to the ideal solar cell material band gap value (about 1.5 eV) and high visible light absorption coefficient.
[0003] However, although the CZTS thin film solar cell has many advantages, its promotion in practical application is still restricted by some technical problems. At present, the traditional CZTS thin film solar cell device adopts a bottom backing structure, that is, the structure of the cell from the substrate is back electrode, absorption layer (CZTS thin film), buffer layer, window layer and top electrode in turn. This structure has a series of problems in shape and design, which seriously affects the performance and preparation efficiency of the cell.
[0004] More specifically, the bottom backing structure makes the preparation process of the cell need to go through the deposition and processing of multiple layers of materials, and the shape and thickness of each layer of material need to be accurately controlled, which greatly increases the complexity and difficulty of preparation. The back electrode is usually located on the substrate, and its shape and thickness have important influence on the deposition of the subsequent layers and the overall performance of the cell. However, in the traditional bottom backing structure, the preparation of the back electrode often needs complex deposition and annealing treatment, which not only increases the production cost, but also may cause the fluctuation of the cell performance. In the bottom backing structure, the CZTS thin film needs to be deposited on the substrate, and the selection and preparation of the substrate material itself is also a cost. Since the light needs to pass through multiple layers of materials to reach the absorption layer, the utilization rate of light is reduced to some extent, which affects the photoelectric conversion efficiency of the cell. In addition, the window layer and the buffer layer in the traditional structure often adopt relatively thick materials to ensure the realization of their functions, but this further increases the loss of light and limits the improvement of photoelectric conversion efficiency.
[0005] In view of the above problems, it is urgent for the industry to develop a new CZTS thin film solar cell structure to simplify the preparation process, improve the material utilization rate and photoelectric conversion efficiency. SUMMARY
[0006] In view of the above problems, the application aims to provide a Cu2ZnSnS4 thin film solar cell device with a top substrate structure, which comprises, from top to bottom, a top electrode, a window layer, a buffer layer, an absorbing layer (CZTS thin film) and a back electrode, which overturns the traditional bottom substrate structure preparation idea and provides a new direction for the development of CZTS thin film solar cells.
[0007] The application adopts the technical scheme of a Cu2ZnSnS4 thin film solar cell device with a top substrate structure, which comprises, from top to bottom, a top electrode, a window layer, a hole transport layer, a buffer layer, an absorbing layer and a back electrode, wherein the absorbing layer is a Cu2ZnSnS4 thin film.
[0008] The top electrode is made of a high-conductivity metal or metal alloy material, and the material is selected from at least one of aluminum (Al), silver (Ag) and copper (Cu).
[0009] The window layer is made of a high-transmittance material, which is used to improve the light transmittance into the cell.
[0010] The hole transport layer is made of inorganic manganese sulfide (MnS), which is used to improve the transmission efficiency of electrons.
[0011] The buffer layer is made of a non-toxic semiconductor material capable of forming a good band match, and the material is selected from at least one of cadmium sulfide (CdS) and amorphous silicon (a-Si).
[0012] The absorbing layer Cu2ZnSnS4 thin film has a well-crystallized structure, which is used to absorb sunlight and generate photo-generated carriers.
[0013] The back electrode is arranged below the absorbing layer and is used to collect photo-generated holes.
[0014] The device further comprises a substrate below the back electrode, the substrate is made of a material having a good ohmic contact with the material of the back electrode, and the material is selected from conductive oxide materials such as FTO; the combined structure of the window layer and the hole transport layer is arranged between the top electrode and the absorbing layer, which is used to optimize the light transmittance and the electron transmission path, thereby improving the photoelectric conversion efficiency.
[0015] The top substrate structure of the device enables the absorbing layer Cu2ZnSnS4 thin film to be directly deposited on the back electrode without an additional substrate support structure, and the top electrode, the window layer, the hole transport layer, the buffer layer and the back electrode are sequentially stacked to form a compact and efficient photoelectric conversion structure.
[0016] The beneficial effects of the technical scheme are: the top lining structure Cu2ZnSnS4 thin film solar cell device innovatively designs in shape and structure, improves photoelectric conversion efficiency, simplifies preparation process, improves material utilization rate and battery stability, provides new opportunities for the development and application of Cu2ZnSnS4 thin film solar cell, and embodies as follows:
[0017] Firstly, the design of the top lining structure makes the light first pass through the high-transmittance window layer into the battery, which effectively reduces the reflection and absorption loss of light on the substrate and back electrode, thereby significantly improving the utilization rate of light; the hole transport layer adopts inorganic manganese sulfide (MnS), which has excellent optical properties, further enhances the light transmittance, and promotes the effective transmission of electrons, thereby improving the photoelectric conversion efficiency; the absorption layer Cu2ZnSnS4 thin film as the core material of light absorption has a crystalline structure that optimizes the light absorption performance and ensures efficient photo-generated carrier generation.
[0018] Secondly, the top lining structure overturns the preparation process of the traditional bottom lining structure, making the battery preparation process more flexible; by reducing the deposition and annealing process of the back electrode, the preparation process is simplified, and the production cost is significantly reduced; the functional layers (such as the top electrode, the window layer, the hole transport layer, the buffer layer and the absorption layer) are sequentially stacked, forming a compact and efficient photoelectric conversion structure, improving the production efficiency and material utilization rate; the top lining structure allows the absorption layer Cu2ZnSnS4 thin film to be directly deposited on the back electrode without additional substrate support, which not only improves the material utilization rate, but also enhances the stability of the battery; the buffer layer adopts a non-toxic semiconductor material that can form a good band matching, such as cadmium sulfide (CdS) or amorphous silicon (a-Si), which effectively reduces the lattice mismatch and band gap step between the absorption layer and the window layer, improves the separation efficiency of photo-generated carriers, and ensures the long-term stability of the battery.
[0019] Finally, the top lining structure Cu2ZnSnS4 thin film solar cell device proposed for the first time overturns the preparation idea of the traditional bottom lining structure, providing a new direction for the development of Cu2ZnSnS4 thin film solar cell, such as optimizing the preparation process, using high-conductivity top electrode material, high-transmittance window layer material, inorganic hole transport layer and non-toxic buffer layer material, further improving the photoelectric conversion efficiency and stability of Cu2ZnSnS4 thin film solar cell; the top lining structure enables Cu2ZnSnS4 thin film solar cell to maintain low cost while improving photoelectric conversion efficiency, making large-scale commercial application possible, and having broad market prospects and application value. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1is a cross-sectional structure schematic diagram of a top-liner structure Cu2ZnSnS4 thin film solar cell device in the embodiment.
[0021] Figure 2 is a process flow schematic diagram of a top-liner structure Cu2ZnSnS4 thin film solar cell device in the embodiment.
[0022] BRIEF DESCRIPTION OF DRAWINGS 1 - top electrode, 2 - window layer, 3 - hole transport layer, 4 - buffer layer, 5 - absorption layer, 6 - back electrode. DETAILED DESCRIPTION
[0023] The utility model provides a kind of Cu2ZnSnS4 thin film solar cell device of top-liner structure, the technical scheme of the utility model will be explained in detail in conjunction with specific embodiment below, so that the person skilled in the art can understand and implement the utility model.
[0024] Embodiment 1
[0025] A kind of Cu2ZnSnS4 thin film solar cell device of top-liner structure, its structure is top electrode 1, window layer 2, hole transport layer 3, buffer layer 4, absorption layer 5 and back electrode 6 in turn from top to bottom, specific implementation is as follows:
[0026] Top electrode 1: high conductivity metal aluminum (Al) is selected as top electrode 1 material;By physical vapor deposition method, such as sputtering deposition, prepare a layer of aluminum electrode with thickness of about 100-200 nanometers on substrate.
[0027] Window layer 2: high transmittance material, such as transparent conductive oxide (TCO), is selected as window layer 2;By chemical vapor deposition (CVD) or physical vapor deposition (PVD) method, prepare a layer of window layer 2 with thickness of about 50-100 nanometers on top electrode 1.
[0028] Hole transport layer 3: inorganic material manganese sulfide (MnS) is selected as hole transport layer 3 material;By magnetron sputtering method, prepare a layer of manganese sulfide hole transport layer 3 with thickness of about 20-50 nanometers on window layer 2.
[0029] Buffer layer 4: non-toxic semiconductor material cadmium sulfide (CdS) is selected as buffer layer 4 material;By chemical bath deposition (CBD) method, prepare a layer of cadmium sulfide buffer layer 4 with thickness of about 10-30 nanometers on hole transport layer 3.
[0030] Absorption layer 5: Cu2ZnSnS4 is selected as absorption layer 5 material;By chemical water bath method, first prepare Cu2ZnSnS4 precursor film, then after sulfidation heat treatment, get well crystallized Cu2ZnSnS4 film, thickness is about 1-2 microns.
[0031] Back electrode 6: a metal or metal alloy material with good conductivity, such as copper (Cu), is selected as the back electrode 6; a layer of back electrode 6 with a thickness of about 100-200 nanometers is prepared on the absorption layer 5 by physical vapor deposition or chemical vapor deposition method.
[0032] Substrate: if additional support structure is needed, a conductive oxide material such as FTO can be selected as the substrate; the substrate can be prepared below the back electrode 6 by physical vapor deposition or chemical vapor deposition method.
[0033] The top substrate structure adopted in this embodiment allows light to first enter the cell through the high-transmittance window layer 2, reducing the loss of light on the substrate and the back electrode 6, and improving the utilization of light and the photoelectric conversion efficiency; the hole transport layer 3 uses inorganic manganese sulfide (MnS), which improves the light transmittance and electron transport efficiency; the buffer layer 4 selects non-toxic cadmium sulfide (CdS), which reduces the lattice mismatch and band gap step between the absorption layer 5 and the window layer 2, and improves the separation efficiency of photo-generated carriers; the absorption layer 5 Cu2ZnSnS4 thin film is prepared by chemical water bath method and sulfuration heat treatment, obtaining a well-crystallized thin film that optimizes the light absorption performance; the top electrode 1, window layer 2, hole transport layer 3, buffer layer 4 and back electrode 6 are sequentially stacked to form a compact and efficient photoelectric conversion structure.
[0034] The top substrate structure Cu2ZnSnS4 thin film solar cell device of this embodiment has high photoelectric conversion efficiency, simplified preparation process, improved material utilization and cell stability; by optimizing the materials and preparation process of each functional layer, the performance of the cell is further improved, which provides the possibility for large-scale commercial application of Cu2ZnSnS4 thin film solar cells.
[0035] Example 2
[0036] A top substrate structure Cu2ZnSnS4 thin film solar cell device, its structure is also from top to bottom in turn for top electrode 1, window layer 2, hole transport layer 3, buffer layer 4, absorption layer 5 and back electrode 6, but the specific implementation steps and selected materials are different, as follows:
[0037] In this embodiment, high-conductivity silver (Ag) is selected as the material of the top electrode 1, which has lower resistivity and good reflectivity, helping to improve the photoelectric conversion efficiency of the cell; a layer of silver electrode with a thickness of about 150-250 nanometers is prepared on the substrate by evaporation method.
[0038] In this embodiment, another high-transmittance material, such as zinc oxide (ZnO) doped with aluminum (Al) transparent conductive film (AZO), is selected as the window layer 2; an AZO window layer 2 with a thickness of about 70-120 nanometers is prepared on the top electrode 1 by sputtering deposition method.
[0039] In this embodiment, inorganic material manganese sulfide (MnS) is still selected as the hole transport layer 3 material, but the preparation process parameters are adjusted to optimize its performance; a manganese sulfide hole transport layer 3 with a thickness of about 30-60 nanometers is prepared on the window layer 2 by chemical vapor deposition (CVD) method.
[0040] In this embodiment, amorphous silicon (a-Si) is selected as the buffer layer 4 material to replace cadmium sulfide (CdS) to avoid the use of toxic materials; an amorphous silicon buffer layer 4 with a thickness of about 20-40 nanometers is prepared on the hole transport layer 3 by plasma enhanced chemical vapor deposition (PECVD) method.
[0041] In this embodiment, Cu2ZnSnS4 is still selected as the absorber layer 5 material, but the formula of the chemical water bath method and the conditions of the sulfuration heat treatment are adjusted to optimize the crystalline quality and light absorption performance of the film; a well-crystallized Cu2ZnSnS4 film with a thickness of about 1.2-1.8 microns is obtained by the optimized chemical water bath method and sulfuration heat treatment.
[0042] In this embodiment, a metal alloy material with good conductivity, such as aluminum-copper alloy (Al-Cu), is selected as the back electrode 6 to improve the adhesion and conductivity with the absorber layer 5; an aluminum-copper alloy back electrode 6 with a thickness of about 120-200 nanometers is prepared on the absorber layer 5 by sputtering deposition method; if additional support structure is needed, conductive oxide materials such as ITO can be selected as the substrate to provide higher transmittance and conductivity; the substrate can be prepared below the back electrode 6 by sputtering deposition or chemical vapor deposition method.
[0043] This embodiment also adopts a top substrate structure, but different materials for the top electrode 1, window layer 2, buffer layer 4 and back electrode 6 are selected, and the preparation process of the hole transport layer 3 and absorber layer 5 is optimized to further improve the photoelectric conversion efficiency and stability of the battery; the top electrode 1 is selected to be silver (Ag) material, which has lower resistivity and good reflectivity, helping to improve the photoelectric conversion efficiency of the battery; the window layer 2 is selected to be AZO material, which has higher transmittance and conductivity, reducing light loss; the buffer layer 4 is selected to be amorphous silicon (a-Si) material, avoiding the use of toxic cadmium sulfide (CdS) and improving the environmental friendliness of the battery; by optimizing the preparation process of the hole transport layer 3 and absorber layer 5, the crystalline quality and light absorption performance of the film are improved, further improving the photoelectric conversion efficiency of the battery.
[0044] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims
1. A top-padded structure Cu2ZnSnS4 thin film solar cell device, characterized in that: The device is structured from top to bottom as a top electrode, a window layer, a hole transport layer, a buffer layer, an absorbing layer and a back electrode, wherein the absorbing layer is a Cu2ZnSnS4 thin film layer.
2. A top-priority structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The top electrode is a high-conductivity metal or metal alloy material, and the material is aluminum (Al) or silver (Ag) or copper (Cu).
3. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The window layer is a high-transmittance material, and the light is transmitted into the battery.
4. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The hole transport layer is an inorganic material manganese sulfide (MnS).
5. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The buffer layer is a semiconductor material, and is selected from cadmium sulfide (CdS) or amorphous silicon (a-Si).
6. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The absorbing layer Cu2ZnSnS4 thin film is a crystalline structure.
7. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The back electrode is arranged below the absorbing layer.
8. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The device further comprises a substrate below the back electrode, and the FTO conductive oxide material is selected.
9. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to claim 1, characterized in that: The combination structure of the window layer and the hole transport layer is arranged between the top electrode and the absorbing layer.
10. The top-pavement structure Cu2ZnSnS4 thin film solar cell device according to any one of claims 1 to 9, characterized in that: The top substrate structure of the device enables the Cu2ZnSnS4 thin film of the absorbing layer to be deposited on the back electrode, without the need for an additional substrate support structure, and the top electrode, the window layer, the hole transport layer, the buffer layer and the back electrode are sequentially stacked to form a compact and efficient photoelectric conversion structure.