Solar cell, preparation method thereof and photovoltaic module
By using 2-methylthio-2-imidazoline hydroiodate as a passivation layer material in perovskite solar cells, the problem of perovskite absorber layer interface optimization was solved, thereby improving photoelectric conversion efficiency and enhancing device stability.
Patent Information
- Application Number
- CN202411807527.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-11-25
Smart Images
Figure CN121013569A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of solar cells, and more particularly to a solar cell and its preparation method, and a photovoltaic module. Background Technology
[0002] Perovskite solar cells are devices that convert solar energy into electrical energy. They have excellent photoelectric properties and are simple in structure and low in manufacturing cost.
[0003] The perovskite absorber layer, as a crucial structure in perovskite solar cells, plays a vital role in their performance. Optimizing the interface of the perovskite absorber layer to improve its performance and thus enhance the photoelectric conversion efficiency of the solar cell has become a pressing technical challenge. Summary of the Invention
[0004] To address the aforementioned technical problems, this application discloses a solar cell and its fabrication method, as well as a photovoltaic module, to improve the photoelectric conversion efficiency of perovskite solar cells.
[0005] In a first aspect, this application provides a solar cell, including a substrate and a hole transport layer, a perovskite absorber layer and a perovskite passivation layer sequentially disposed on the substrate, wherein the perovskite passivation layer contains 2-methylthio-2-imidazoline hydroiodate.
[0006] In some embodiments of this application, the perovskite passivation layer is formed by applying the 2-methylthio-2-imidazoline hydroiodate to the surface of the perovskite absorber layer.
[0007] In some embodiments of this application, the size of the solar cell is not less than 50mm × 50mm.
[0008] In some embodiments of this application, the solar cell includes a perovskite tandem solar cell, the substrate includes a base cell and a composite layer stacked on the base cell, the hole transport layer, the perovskite absorber layer and the perovskite passivation layer are sequentially stacked on the composite layer, and the surface of the composite layer facing the hole transport layer has a textured surface.
[0009] In some embodiments of this application, an electron transport layer, a buffer layer, a first transparent electrode layer, and an antireflection layer are also stacked sequentially on the perovskite passivation layer.
[0010] In some embodiments of this application, the photoelectric conversion efficiency of the solar cell is 15% to 25%.
[0011] Secondly, this application provides a method for fabricating a solar cell as described in the first aspect, comprising the following steps:
[0012] A substrate is provided, and a hole transport layer and a perovskite absorber layer are sequentially formed on the surface of the composite layer of the substrate;
[0013] A first solution containing the 2-methylthio-2-imidazoline hydroiodate is applied to the surface of the perovskite absorber layer to prepare the perovskite passivation layer, wherein the concentration of the 2-methylthio-2-imidazoline hydroiodate in the first solution is 1 mg / L to 3 mg / L.
[0014] Other functional layers are sequentially fabricated on the perovskite passivation layer, and the other functional layers include at least an electron transport layer.
[0015] In some embodiments of this application, the solvent in the first solution is selected from isopropanol.
[0016] Thirdly, this application provides a photovoltaic module, which includes a solar cell as described in the first aspect, or the photovoltaic module includes a solar cell prepared by the preparation method described in the second aspect.
[0017] Compared with the prior art, this application has at least the following beneficial effects:
[0018] This application provides a solar cell and its fabrication method, as well as a photovoltaic module. The solar cell includes a substrate and a hole transport layer, a perovskite absorber layer, and a perovskite passivation layer sequentially disposed on the substrate. The perovskite passivation layer contains 2-methylthio-2-imidazoline hydroiodate, which simultaneously contains an imidazoline ring, a methylthio group, and a hydroiodate ion. The imidazoline ring is basic and electrophilic, and can interact with the surface of the perovskite material in the perovskite absorber layer, which is beneficial for forming a stable interface. The methylthio group can provide effective coordination sites to form coordination bonds with metal ions in the perovskite material, which is beneficial for passivating surface defects in the perovskite absorber layer, reducing trapped states, thereby reducing the recombination rate of charge carriers and the internal stress inside the perovskite absorber layer. The hydroiodate ion can optimize the band matching with the perovskite absorber layer. The combined effect of the three groups not only improves the interfacial stability of the perovskite absorber layer and passivates surface defects, but also optimizes the energy level matching of the perovskite absorber layer and enhances its stability, thereby further improving the photoelectric conversion efficiency of the solar cell. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram of the structure of a solar cell in one embodiment of this application;
[0021] Figure 2 This is a schematic diagram of the structure of a solar cell in another embodiment of this application.
[0022] Explanation of reference numerals in the attached figures: Substrate-1, Hole transport layer-2, Perovskite absorber layer-3, Perovskite passivation layer-4, Electron transport layer-5, Buffer layer-6, First transparent electrode layer-7, Anti-reflection layer-8, Bottom cell-10, Second transparent electrode layer-11, P-type doped crystalline silicon layer-12, First intrinsic amorphous silicon layer-13, N-type silicon wafer-14, Second intrinsic amorphous silicon layer-15, N-type doped crystalline silicon layer-16, Composite layer-17, Positive electrode-91, Back electrode-92. Detailed Implementation
[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0024] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.
[0025] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0026] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.
[0027] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.
[0028] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.
[0029] Currently, the most common perovskite passivation layer material is lithium fluoride (LiF). Although this type of material can passivate the interface of the perovskite absorber layer, its function is relatively simple and it is difficult to further improve the performance of the perovskite absorber layer.
[0030] In view of this, firstly, this application provides a solar cell, such as Figure 1 As shown, the solar cell includes a substrate 1 and a hole transport layer 2, a perovskite absorber layer 3 and a perovskite passivation layer 4 sequentially disposed on the substrate 1, wherein the perovskite passivation layer 4 contains 2-methylthio-2-imidazoline hydroiodate.
[0031] 2-Methylthio-2-imidazoline hydroiodate is commonly used in the preparation of antibacterial agents and insecticides. However, the inventors unexpectedly discovered that including 2-methylthio-2-imidazoline hydroiodate in the perovskite passivation layer significantly improves the photoelectric conversion efficiency of solar cells. This is likely because 2-methylthio-2-imidazoline hydroiodate contains three groups: an imidazoline ring, a methylthio group, and a hydroiodate group. The imidazoline ring has a certain degree of basicity and electrophilicity, enabling it to interact with the surface of the perovskite material in the perovskite absorber layer, which is beneficial for forming a stable interface. The methylthio group provides effective coordination sites, forming coordination bonds with metal ions in the perovskite material, which helps passivate surface defects in the perovskite absorber layer, reduces trapped states, and thus lowers the recombination rate of charge carriers and the internal stress within the perovskite absorber layer. The hydroiodate group optimizes the bandgap matching with the perovskite absorber layer. The combined effect of the above three groups can not only improve the interfacial stability of the perovskite absorber layer and passivate the surface defects of the perovskite absorber layer, but also optimize the energy level matching of the perovskite absorber layer and enhance its stability, thereby further improving the photoelectric conversion efficiency of the solar cell.
[0032] The structural formula of 2-methylthio-2-imidazoline hydroiodate in this application is as follows:
[0033]
[0034] As can be seen from the above structural formula, the 2-methylthio-2-imidazoline hydroiodate of this application contains three groups: an imidazoline ring, a methylthio group, and a hydroiodate group.
[0035] In one optional embodiment, the perovskite passivation layer is formed by applying 2-methylthio-2-imidazoline hydroiodate to the surface of the perovskite absorber layer. By using 2-methylthio-2-imidazoline hydroiodate as the material for forming the perovskite passivation layer, the resulting perovskite passivation layer not only effectively passivates the perovskite absorber layer but also improves the interfacial stability of the perovskite absorber layer, optimizes the energy level matching of the perovskite absorber layer, and enhances the stability of the perovskite absorber layer, thus enabling the solar cell to exhibit better photoelectric conversion performance.
[0036] In one optional implementation, the solar cell has a size of not less than 50mm × 50mm and an effective area of not less than 200mm². 2 For example, the size of the solar cell is 50mm×50mm, 182mm×182mm, or 210mm×210mm. As the size of the solar cell increases, the size of the perovskite absorber layer also increases, making it more susceptible to defects such as pinholes and cracks, and leading to greater parasitic absorption losses. Since the 2-methylthio-2-imidazoline hydroiodate of the perovskite passivation layer in this application contains three groups—imidazoline ring, methylthio, and hydroiodate—it can not only improve the interfacial stability of the perovskite absorber layer and passivate surface defects, but also optimize the energy level matching and enhance the stability of the perovskite absorber layer, making it more suitable for large-size solar cells.
[0037] In one alternative implementation, refer to Figure 1 The solar cell includes a perovskite tandem solar cell. The substrate 1 includes a bottom cell 10 and a composite layer 17 stacked on the bottom cell. A hole transport layer 2, a perovskite absorber layer 3, and a perovskite passivation layer 4 are sequentially stacked on the composite layer 17. The surface of the composite layer 17 facing the hole transport layer 2 has a textured surface. The bottom cell 10, from bottom to top, includes a second transparent electrode layer 11, a P-type doped crystalline silicon layer 12, a first intrinsic amorphous silicon layer 13, an N-type silicon wafer 14, a second intrinsic amorphous silicon layer 15, and an N-type doped crystalline silicon layer 16. Furthermore, an electron transport layer 5 and a first transparent electrode layer 7 are sequentially stacked on the perovskite passivation layer 4.
[0038] The substrate of this application can be a solar cell based on a crystalline silicon substrate, and this application is not limited thereto. To better absorb solar energy, the composite layer of this application has a textured structure on the surface facing the hole transport layer (i.e., the light incident surface). For example, this textured structure can be a pyramid-shaped textured structure. This textured structure provides a higher surface area for the solar cell while reducing light reflection and diffusion. The surface of the hole transport layer and the textured structure of the composite layer have the same shape, both being pyramid-shaped, thus achieving the shape retention requirement of the textured structure. This application does not particularly limit the preparation method of the textured structure, as long as it achieves the purpose of this application; for example, it can be prepared using existing magnetron sputtering methods.
[0039] In one alternative implementation, such as Figure 2 As shown, an electron transport layer 5, a buffer layer 6, a first transparent electrode layer 7, and an antireflection layer 8 are sequentially stacked on the perovskite passivation layer 4. The buffer layer 6 is located on the surface of the electron transport layer 5 opposite to the perovskite absorption layer 3 (i.e., the light incident surface), and the antireflection layer 8 is located on the surface of the first transparent electrode layer 7 opposite to the buffer layer 6. Solar cells incorporating these antireflection layers exhibit higher photoelectric conversion efficiency.
[0040] This application does not impose any particular restrictions on the electrodes of the solar cell, as long as they achieve the purpose of this application. For example, see reference... Figure 1 and Figure 2 A positive electrode 91 can be set on the light-receiving surface of the solar cell, and a back electrode 92 can be set on the back surface of the solar cell.
[0041] The hole transport layer, perovskite absorber layer, perovskite passivation layer, and electron transport layer of this application can also be applied to single-junction perovskite solar cells. This application does not impose any particular restrictions on the structure of the single-junction perovskite solar cell; it can use existing single-junction perovskite solar cell structures.
[0042] Secondly, this application provides a method for fabricating a solar cell as described in the first aspect, comprising the following steps:
[0043] Step A: Provide a substrate, and sequentially prepare a hole transport layer and a perovskite absorber layer on the surface of the composite layer of the substrate;
[0044] Step B: Apply a first solution containing 2-methylthio-2-imidazoline hydroiodate to the surface of the perovskite absorber layer to prepare a perovskite passivation layer. The concentration of 2-methylthio-2-imidazoline hydroiodate in the first solution is 1 mg / L to 3 mg / L.
[0045] Step C: Sequentially prepare other functional layers on the perovskite passivation layer, the other functional layers including at least an electron transport layer.
[0046] In step A, the hole transport layer can be prepared by magnetron sputtering and / or spin coating. When preparing the perovskite absorber layer, a framework layer can be prepared first, and then an organic salt solution can be coated onto the surface of the framework layer, followed by thermal annealing to obtain the perovskite absorber layer. The framework layer can be obtained by vapor deposition of PbI2 and CsX (X representing a halogen element). This application does not particularly limit the type of organic salt; for example, at least two of formamidine hydroiodide (FAI), formamidine hydrobromide (FABr), formamidine hydrochloride (FACl), methylamine iodide (MAI), methylamine bromide (MABr), and methylamine chloride (MACl) can be dissolved in a solvent to obtain an organic salt solution. This application does not particularly limit the coating method of the perovskite absorber layer; for example, spin coating, spray coating, slot coating, and blade coating methods can be used. The thickness of the perovskite absorber layer is 400 nm to 500 nm.
[0047] In step B, the concentration of 2-methylthio-2-imidazoline hydroiodate in the first solution is 1 mg / L to 3 mg / L, which is beneficial for the full dissolution of 2-methylthio-2-imidazoline hydroiodate while avoiding its aggregation or phase separation. The first solution containing 2-methylthio-2-imidazoline hydroiodate can be applied to the surface of the perovskite absorber layer by slit coating or spin coating to form a wet perovskite passivation layer. After drying, the perovskite passivation layer is formed. This application does not impose any special restrictions on the process parameters of slit coating. For example, the coating gap is 70 μm to 120 μm and the coating speed is 5 mm / s to 10 mm / s, as long as the purpose of this application can be achieved.
[0048] In step C, other functional layers may also include a buffer layer, a first transparent electrode layer, and an antireflection layer.
[0049] In one alternative embodiment, the solvent in the first solution is selected from isopropanol, which facilitates the complete dissolution of 2-methylthio-2-imidazoline hydroiodate.
[0050] This application does not impose any particular limitations on the fabrication methods of the electron transport layer, buffer layer, first transparent electrode layer, antireflection layer, and electrodes. For example, the electron transport layer material C can be used. 60An electron transport layer with a thickness of 10 nm to 20 nm can be obtained by thermal evaporation deposition using a metal evaporation device; a buffer layer with a thickness of 10 nm to 17 nm can be prepared using atomic layer deposition (ALD) using tin dioxide (SnO2) as the buffer layer material; a first transparent electrode layer with a thickness of 70 nm to 110 nm can be prepared using indium gallium zinc oxide (IZO) as the transparent electrode layer material using magnetron sputtering (PVD); an antireflection layer with a thickness of 80 nm to 130 nm can be obtained by thermal evaporation deposition using LiF or MgF2 as the antireflection layer material; and positive and back electrodes with an electrode thickness of 300 nm to 500 nm can be obtained by thermal evaporation deposition using Ag as the electrode material.
[0051] This application does not impose any particular limitation on the thickness of the perovskite passivation layer; it can be a nanoscale film structure, as long as it achieves the purpose of this application. For example, the thickness of the perovskite passivation layer is 0.5 nm to 2 nm.
[0052] The solar cell fabrication method provided in this application prepares a perovskite passivation layer comprising 2-methylthio-2-imidazoline hydroiodate material. Compared with existing perovskite passivation layer preparation methods, the prepared perovskite passivation layer not only improves the interfacial stability of the perovskite absorber layer and passivates surface defects of the perovskite absorber layer, but also optimizes the energy level matching of the perovskite absorber layer and enhances its stability. Furthermore, the fabrication method of this application has the advantages of simple fabrication process and convenient operation, which is conducive to industrial production and suitable for large-scale manufacturing of perovskite-silicon tandem solar cells.
[0053] Thirdly, this application provides a photovoltaic module, which includes a solar cell as described in the first aspect, or the photovoltaic module includes a solar cell prepared by the preparation method described in the second aspect.
[0054] This application also provides a photovoltaic module for converting received light energy into electrical energy and transmitting it to an external load. The photovoltaic module includes: at least one cell string, which is composed of multiple solar cells connected together; an encapsulating film for covering the surface of the cell string; and a cover plate for covering the surface of the encapsulating film facing away from the cell string.
[0055] Example
[0056] The solar cells, their fabrication methods, and photovoltaic modules of this application will be further described below with reference to more specific embodiments.
[0057] Example 1
[0058] <Substrate Preparation>
[0059] A textured base cell (50mm × 50mm) is provided, and a 20nm thick indium tin oxide (ITO) film is prepared on the light-receiving surface of the base cell as a composite layer to obtain the substrate. The base cell, from bottom to top, comprises a 100nm thick second transparent electrode layer, a 10nm thick P-type doped crystalline silicon layer, a 7nm thick first intrinsic amorphous silicon layer, a 120μm thick N-type silicon wafer, a 7nm thick second intrinsic amorphous silicon layer, and a 6nm thick N-type doped crystalline silicon layer.
[0060] <Preparation of Hole Transport Layer>
[0061] A 20 nm thick nickel oxide hole transport layer was deposited on the surface of the carrier recombination layer of the substrate by magnetron sputtering.
[0062] <Preparation of Perovskite Absorber Layer>
[0063] A perovskite absorber layer with a thickness of 450 nm was prepared on the surface of the hole transport layer by co-evaporation.
[0064] <Preparation of Perovskite Passivation Layer>
[0065] 2-Methylthio-2-imidazoline hydroiodate was added to isopropanol to obtain a first solution, wherein the concentration of 2-methylthio-2-imidazoline hydroiodate in the first solution was 1 mg / L; the first solution was coated on the surface of the perovskite absorber layer by a slit coating process, wherein the slit coating process had a coating gap of 80 μm and a coating speed of 8 mm / s, thereby preparing a perovskite passivation layer.
[0066] <Preparation of other functional layers>
[0067] An electron transport layer, a buffer layer, and a first transparent electrode layer are sequentially prepared on the surface of the perovskite passivation layer.
[0068] The electron transport layer is prepared by depositing a 20nm thick C layer on the perovskite absorber layer. 60 As an electron transport layer;
[0069] The preparation process of the buffer layer is as follows: a 10 nm thick SnO2 layer is prepared on the electron transport layer using atomic layer deposition as a buffer layer;
[0070] The fabrication process of the first transparent electrode layer is as follows: a 100 nm thick layer of IZO is prepared on the electron transport layer by magnetron sputtering as the first transparent electrode layer.
[0071] <Solar Cell Fabrication>
[0072] A 350 nm thick silver layer was thermally evaporated onto the first transparent electrode layer as the positive electrode. A 300 nm thick silver layer was thermally evaporated onto the second transparent electrode layer of the bottom cell as the back electrode. Then, a 100 nm thick anti-reflection layer was deposited by thermal evaporation of LiF using a metal evaporation device, resulting in the solar cell. The cell structure is as follows. Figure 2 As shown.
[0073] Examples 2 to 3
[0074] Except for adjusting the concentration of 2-methylthio-2-imidazoline hydroiodate in the first solution according to Table 1 in the <Preparation of Perovskite Passivation Layer>, the rest is the same as in Example 1.
[0075] Comparative Examples 1 to 2
[0076] Except for adjusting the concentration of 2-methylthio-2-imidazoline hydroiodate in the first solution according to Table 1 in the <Preparation of Perovskite Passivation Layer>, the rest is the same as in Example 1.
[0077] Table 1: Preparation parameters of Examples 1-3 and Comparative Examples 1-2
[0078] First solution concentration (mg / L) Example 1 1 Example 2 2 Example 3 3 Comparative Example 1 0.3 Comparative Example 2 10
[0079] Open-circuit voltage, short-circuit current density, and fill factor tests:
[0080] The current (I)-voltage (V) of the solar cells in each embodiment and comparative example were measured using an IV tester (model: MX-MPVC-A20, manufacturer: Suzhou Maiwei Technology Co., Ltd.) to obtain the open-circuit voltage, short-circuit current density and fill factor of the solar cells.
[0081] Photoelectric conversion efficiency test:
[0082] The current (I)-voltage (V) of the solar cells in each embodiment and comparative example were measured using an IV tester (model: MX-MPVC-A20, manufacturer: Suzhou Maiwei Technology Co., Ltd.) to obtain the photoelectric conversion efficiency (PCE) of the solar cells.
[0083] Table 2: Performance data of Examples 1-3 and Comparative Examples 1-2
[0084]
[0085] As can be seen from Examples 1-3 and Comparative Examples 1 and 2, when the concentration of the first solution is too low (e.g., Comparative Example 1), the photoelectric conversion efficiency, open-circuit voltage, fill factor, and short-circuit current density of the solar cell are all low. This may be because the content of 2-methylthio-2-imidazoline hydroiodate is too low, resulting in a decrease in the passivation effect, interface stabilization effect, and energy level matching effect of the perovskite absorber layer, thereby affecting the performance of the solar cell. When the concentration of the first solution is too high (e.g., Comparative Example 2), the photoelectric conversion efficiency, open-circuit voltage, fill factor, and short-circuit current density of the solar cell are all low. This may be because the content of 2-methylthio-2-imidazoline hydroiodate is too high, resulting in the formation of additional aggregation or phase separation of 2-methylthio-2-imidazoline hydroiodate on the surface or inside of the perovskite absorber layer. Such aggregation or phase separation not only does not further improve the passivation effect, but may instead become... A new non-radiative recombination center; and the improved photoelectric conversion efficiency, open-circuit voltage, fill factor, and short-circuit current density of the solar cells in Examples 1 to 3 of this application are likely due to the fact that 2-methylthio-2-imidazoline hydroiodate contains three groups: an imidazoline ring, a methylthio group, and a hydroiodate group. The imidazoline ring is a five-membered heterocycle containing two nitrogen atoms, which has certain basicity and electrophilicity. This allows it to interact with the electron-deficient perovskite material surface, contributing to the formation of a stable interface. In addition, the presence of nitrogen atoms in the imidazoline ring is also beneficial for electron transport, facilitating electron injection and extraction between the electron transport layer and the perovskite absorber layer. The methylthio group is a functional group containing sulfur atoms. Sulfur atoms have a large atomic radius and high electron cloud density, providing effective coordination sites for metal ions (such as lead ions Pb) in the perovskite material. 2 The formation of weaker coordination bonds helps passivate surface defects and reduce trapped states, thereby lowering the recombination rate of charge carriers. Furthermore, the methyl thio group can enhance the hydrophobicity of the material, which is beneficial to improving the device stability of solar cells, especially to resisting degradation caused by humidity. The hydroiodate ion, as an anionic part, not only provides the necessary negative charge balance, but the introduction of iodide ions will also have a positive impact on the overall electrical properties and energy level arrangement of the solar cell, and can optimize the band matching with the perovskite absorber layer.
[0086] The present application discloses a solar cell, its preparation method, and a photovoltaic module. Specific examples have been used to illustrate the principles and implementation methods of the present application. The descriptions of the above embodiments are only for the purpose of helping to understand the technical solutions and core inventive points of the embodiments of the present application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present application. Therefore, the content of this specification should not be construed as a limitation of the present application.
Claims
1. A solar cell, characterized in that, It includes a substrate and a hole transport layer, a perovskite absorption layer and a perovskite passivation layer sequentially disposed on the substrate, wherein the perovskite passivation layer contains 2-methylthio-2-imidazoline hydroiodate.
2. The solar cell according to claim 1, characterized in that, The perovskite passivation layer is formed by applying the 2-methylthio-2-imidazoline hydroiodate to the surface of the perovskite absorber layer.
3. The solar cell according to claim 1, characterized in that, The size of the solar cell is not less than 50mm × 50mm.
4. The solar cell according to claim 1, characterized in that, The solar cell includes a perovskite tandem solar cell, and the substrate includes a base cell and a composite layer stacked on the base cell. The hole transport layer, the perovskite absorber layer and the perovskite passivation layer are stacked sequentially on the composite layer, and the surface of the composite layer facing the hole transport layer has a textured surface.
5. The solar cell according to claim 4, characterized in that, An electron transport layer, a buffer layer, a first transparent electrode layer, and an antireflection layer are also stacked sequentially on the perovskite passivation layer.
6. The solar cell according to any one of claims 1 to 5, characterized in that, The photoelectric conversion efficiency of the solar cell is 15% to 25%.
7. A method for preparing a solar cell according to any one of claims 1 to 6, characterized in that, Includes the following steps: A substrate is provided, and a hole transport layer and a perovskite absorber layer are sequentially formed on the surface of the composite layer of the substrate; A first solution containing the 2-methylthio-2-imidazoline hydroiodate is applied to the surface of the perovskite absorber layer to prepare the perovskite passivation layer, wherein the concentration of the 2-methylthio-2-imidazoline hydroiodate in the first solution is 1 mg / L to 3 mg / L. Other functional layers are sequentially fabricated on the perovskite passivation layer, and the other functional layers include at least an electron transport layer.
8. The preparation method according to claim 7, characterized in that, The solvent in the first solution is selected from isopropanol.
9. A photovoltaic module, characterized in that, The photovoltaic module comprises the solar cell according to any one of claims 1 to 6, or the photovoltaic module comprises the solar cell prepared by the preparation method according to any one of claims 7 to 8.