Conductive substrate layer and preparation method and application thereof

Abstract

The embodiment of the invention provides a conductive substrate layer and a preparation method and application thereof. The preparation method of the conductive substrate layer comprises the following steps: adding a liquid indium-tin alloy on the surface of one side of a first substrate layer, then covering the surface of the liquid indium-tin alloy with a second substrate layer for lamination, then removing the second substrate layer, and carrying out an in-situ oxidation reaction on the laminated indium-tin alloy to obtain the conductive substrate layer. In the preparation process of the conductive substrate layer, the microstructure and stress distribution of the ITO thin film in the conductive substrate layer can be regulated and controlled through specific indium tin alloy and setting of pressing process parameters, the ITO thin film with a gradient interface and a local strain buffer structure is formed, and therefore cracks are effectively reduced; in addition, the preparation method is simple in technological process, large-area compatible and continuous production can be achieved, and a new path is provided for large-scale production of the conductive substrate layer.

Description

Technical Field

[0001] This application relates to the field of solar cell technology, specifically to a conductive substrate layer, its preparation method, and its application, and more particularly to a method for preparing a conductive substrate layer, a conductive substrate layer, an ITO thin film layer, a perovskite cell, and a photovoltaic module. Background Technology

[0002] With the improvement of my country's energy structure, more and more new energy sources are replacing traditional thermal power generation. Among them, solar energy is a renewable energy source. Solar power generation is simple to install, requires little site space, and is suitable for various occasions and needs. Therefore, it is widely used in various fields.

[0003] Perovskite solar cells (PSCs) are a new generation of photovoltaic technology, and have become a research focus due to their high photoelectric conversion efficiency and low-cost solution processing.

[0004] The fabrication of perovskite solar cells involves transparent conductive films, typically made of indium oxycarbonate (ITO). However, traditional ITO film fabrication methods, such as magnetron sputtering, electron beam evaporation, or solution methods, generally rely on high-vacuum equipment, high-temperature annealing processes, or complex post-processing. This not only leads to high production costs but also results in films with poor adaptability to flexible substrates, easily cracking during bending, severely limiting their widespread application in flexible electronics.

[0005] For magnetron sputtering, by optimizing sputtering parameters (such as power, gas pressure, and oxygen / argon ratio) and combining them with advanced technologies such as energy filtering, ITO thin films can be directly deposited at room temperature or lower temperatures (<150°C). This method effectively avoids damage to flexible plastic substrates caused by high temperatures and achieves good compatibility with flexible substrates. However, it sacrifices some of the conductivity of the ITO thin film, which may lead to a decrease in the performance of the final flexible electronic device.

[0006] For spray pyrolysis, a technology has been developed to atomize an indium- and tin-containing precursor solution into tiny droplets, which are then directly sprayed onto a heated substrate surface. The droplets undergo solvent evaporation, precursor decomposition, and reaction on the substrate, ultimately forming an ITO thin film. This method operates under atmospheric or near-atmospheric pressure, significantly reducing reliance on high-vacuum equipment; however, the high-temperature operating environment can easily cause high-melting-point precursor materials to precipitate or sinter at the nozzle, leading to nozzle blockage and increasing the complexity of process control and equipment maintenance.

[0007] In view of the problems existing in the current technology, it is very necessary to develop a new method for preparing ITO thin films.

[0008] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the Invention

[0009] This application provides a conductive substrate layer, its preparation method, and its application to solve or alleviate one or more of the technical problems mentioned above.

[0010] The first aspect of this application provides a method for preparing a conductive substrate layer, the method comprising the following steps: Liquid indium-tin alloy is added to one side of the first substrate layer. Then, a second substrate layer is placed on top of the liquid indium-tin alloy and pressed together. After that, the second substrate layer is removed. The pressed indium-tin alloy undergoes an in-situ oxidation reaction to obtain a conductive substrate layer.

[0011] Optionally, the materials of the first substrate layer and the second substrate layer are each independently selected from any one or a combination of at least two of polyimide, polyethylene terephthalate, polyethylene naphthalate, or metal foil.

[0012] Optionally, the thickness of the first substrate layer and the second substrate layer are each independently 100-300 μm.

[0013] Optionally, the preparation method of the liquid indium-tin alloy includes: mixing indium and tin at 200-250°C for 20-40 minutes to obtain the liquid indium-tin alloy.

[0014] Optionally, with the sum of the number of indium and tin atoms being 100, the ratio of the number of indium and tin atoms is (88-98):(12-2).

[0015] Optionally, the liquid indium-tin alloy is added dropwise.

[0016] Optionally, the diameter of the added droplets is 3-5 mm.

[0017] Optionally, the second base layer is preheated before lamination.

[0018] Optionally, the preheating temperature is 180-200℃.

[0019] Optionally, the pressure used for pressing is 2-8 kPa, and the pressing time is 1-5 min.

[0020] Optionally, the second base layer can be removed by vertical lifting.

[0021] Optionally, the in-situ oxidation reaction is carried out in the presence of oxygen.

[0022] Secondly, embodiments of this application provide a conductive substrate layer prepared by the preparation method described in the first aspect, the conductive substrate layer comprising a first substrate layer and an ITO thin film layer located on one side surface of the first substrate layer.

[0023] Optionally, the thickness of the ITO film is 100-500 nm.

[0024] Thirdly, embodiments of this application provide an ITO thin film layer, wherein the method for preparing the ITO thin film layer includes: removing the first substrate layer from the conductive substrate layer prepared in the first aspect to obtain the ITO thin film layer.

[0025] Fourthly, embodiments of this application provide a perovskite solar cell, which includes a flexible conductive transparent substrate layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, and a metal electrode layer stacked sequentially; the flexible conductive transparent substrate layer is the conductive substrate layer described in the first aspect.

[0026] Fifthly, embodiments of this application provide a photovoltaic module, the photovoltaic module including the perovskite cell described in the fourth aspect.

[0027] The embodiments of this application employing the above-described technical solution may have the following advantages: In the preparation of conductive substrates, the microstructure and stress distribution of ITO films in conductive substrates can be controlled by setting specific indium tin alloys and lamination process parameters, forming ITO films with gradient interfaces and local strain buffer structures, thereby effectively reducing crack generation. In addition, the preparation method has a simple process flow, is compatible with large areas, and can be continuously produced, providing a new path for the large-scale production of conductive substrates. Attached Figure Description

[0028] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0029] Figure 1 This is a method for preparing a conductive substrate layer in a specific embodiment of this application; Figure 2 This is the structure of the flexible perovskite solar cell in a specific embodiment of this application; Figure 3 These are scanning electron microscope (SEM) images of the perovskite absorber layer in the perovskite solar cells prepared in Example 2 and Comparative Example 1. Figure 4 This is a scanning electron microscope image of the side cross-section of the perovskite solar cell prepared in Example 3; Figure 5 These are IV curves of the perovskite solar cells prepared in Examples 1-4 and Comparative Example 1; Figure 6 These are bending resistance test images of the perovskite solar cells prepared in Example 3 and Comparative Example 1; Explanation of reference numerals in the attached figures: 1. First substrate layer; 2. ITO thin film layer; 3. Electron transport layer; 4. Perovskite absorber layer; 5. Hole transport layer; 6. Metal electrode layer. Detailed Implementation

[0030] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings. In the drawings, for clarity, the dimensions of layers, regions, and elements, as well as their relative dimensions, may be exaggerated. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0031] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, components, areas, layers, and / or portions, these elements, components, areas, layers, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, component, area, layer, or portion from another element, component, area, layer, or portion. Therefore, without departing from the teachings of this application, the first element, component, area, layer, or portion discussed below may be referred to as a second element, component, area, layer, or portion. And the discussion of a second element, component, area, layer, or portion does not imply that the first element, component, area, layer, or portion necessarily exists in this application.

[0032] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0033] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0034] In this application, when numerical intervals (i.e., numerical ranges) are involved, unless otherwise specified, the distribution of selectable numerical values ​​within the numerical interval is considered continuous, and includes the two endpoints of the numerical interval (i.e., the minimum and maximum values), as well as every numerical value between these two endpoints. Unless otherwise specified, when a numerical interval refers only to integers within that numerical interval, it includes the two endpoint integers of the numerical range, as well as every integer between the two endpoints, which is equivalent to directly listing every integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical ranges disclosed in this application should be understood to include any and all subranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, percentage, ratio, etc. The term "numerical interval" can be broadly included to include percentage intervals, ratio intervals, proportion intervals, etc.

[0035] This application provides a conductive substrate layer, its preparation method, and its application technology. Details are provided below.

[0036] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. It should be understood that these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein.

[0037] This application provides a method for preparing a conductive substrate layer, such as... Figure 1 As shown, the method for preparing the conductive substrate layer includes the following steps: Liquid indium-tin alloy is added to one side of the first substrate layer. Then, a second substrate layer is placed on top of the liquid indium-tin alloy and pressed together. After that, the second substrate layer is removed. The pressed indium-tin alloy undergoes an in-situ oxidation reaction to obtain a conductive substrate layer.

[0038] It should be noted that, in the past, the problems in the preparation of ITO thin films in conductive substrates were usually addressed by optimizing the magnetron sputtering process parameters to reduce the deposition temperature of the ITO thin film. However, this would sacrifice some of the conductivity of the ITO thin film, resulting in a decrease in the performance of the solar cell. Alternatively, spray pyrolysis technology was developed to atomize the indium and tin precursor solution into tiny droplets and spray them directly onto the substrate surface. Although this reduced the need for high vacuum, the high-temperature operating environment could cause high-melting-point precursor materials to precipitate or sinter at the nozzle, causing nozzle blockage, increasing the complexity of process control and the difficulty of equipment maintenance.

[0039] In this application, a novel method for preparing a conductive substrate is developed. By using a liquid indium tin alloy and pressing it together, the microstructure and stress distribution of the ITO thin film in the conductive substrate can be effectively controlled, forming an ITO thin film with a gradient interface and a local strain buffer structure, which effectively reduces the generation of cracks.

[0040] In this application, the conductive substrate layer prepared by this method has good interfacial contact properties, chemical stability and thermal stability.

[0041] In this application, a liquid metal imprinting method is used to prepare conductive substrates. This method enables the fabrication of ITO thin films in conductive substrates at temperatures below 150°C and in a conventional air environment, eliminating the need for high-vacuum sputtering equipment and significantly reducing energy consumption and equipment investment. This preparation process not only significantly simplifies the traditional multi-step process flow but also allows for continuous roll-to-roll production, making it suitable for large-area, low-cost manufacturing and providing a new pathway for the large-scale preparation of conductive substrates.

[0042] In some embodiments, the materials of the first substrate layer and the second substrate layer are each independently selected from any one or a combination of at least two of polyimide, polyethylene terephthalate, polyethylene naphthalate, or metal foil.

[0043] In some embodiments, the thickness of the first substrate layer and the second substrate layer is independently 100-300 μm (exemplary thicknesses are 100 μm, 120 μm, 150 μm, 170 μm, 200 μm, 220 μm, 250 μm, 270 μm, 300 μm, etc.).

[0044] In this application, the purpose of the first base layer is to provide the function of a flexible base, and the purpose of the second base layer is to perform compression and facilitate removal during removal.

[0045] In this application, both the first and second base layers are made of flexible substrates, which facilitates a firm bond during the lamination process and prevents the indium tin alloy from being oxidized.

[0046] In this application, the materials of the first substrate layer and the second substrate layer can be the same or different, and those skilled in the art can adjust them according to actual needs. To ensure ease of operation, the same material is preferred. Those skilled in the art can select and adjust the materials and thicknesses of the first and second substrate layers according to different usage scenarios and the needs of the end product.

[0047] In some embodiments, the method for preparing the liquid indium-tin alloy includes: mixing indium and tin at 200-250°C (exemplarily, the mixing temperature is 200°C, 210°C, 220°C, 230°C, 240°C, 250°C, etc.) for 20-40 min (exemplarily, the mixing time is 20 min, 25 min, 30 min, 35 min, 40 min, etc.) to obtain the liquid indium-tin alloy.

[0048] In some embodiments, with the sum of the number of indium and tin atoms being 100, the ratio of the number of indium and tin atoms is (88-98):(12-2) (exemplarily, the ratio of the number of indium and tin atoms is 88:12, 90:10, 92:8, 95:5, 98:2, etc.).

[0049] It should be noted that when forming a liquid indium-tin alloy, the purity of the added indium and tin must be ensured so that the resulting liquid indium-tin alloy is free of any solid tin dopants, thus exhibiting a good molten state. Specifically, the purity of indium needs to be maintained at above 99.95%, and the purity of tin needs to be maintained at above 99.5%.

[0050] When preparing liquid indium-tin alloy, placing the two in a glass bottle and mixing them at 200-250℃ for 20-40 minutes ensures thorough mixing of indium and tin. If the mixing temperature is too low or the mixing time is too short, it will not be conducive to thorough mixing. If the mixing temperature is too high or the mixing time is too long, it will result in waste of resources.

[0051] In some embodiments, the liquid indium-tin alloy is added dropwise.

[0052] In some embodiments, the diameter of the added droplets is 3-5 mm (exemplary diameters include 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.).

[0053] In this application, liquid indium tin alloy is dropped onto one side of the surface of the first substrate layer, and the liquid indium tin alloy is uniformly spread between the two substrate layers by rapid pressing of the second substrate layer. The liquid indium tin alloy is added by drawing it in with a glass Pasteur pipette.

[0054] In some embodiments, the second substrate layer is preheated before pressing; the preheating temperature is 180-200°C (exemplary temperatures include 180°C, 185°C, 190°C, 195°C, 200°C, etc.).

[0055] In this application, preheating the second substrate layer facilitates the uniform spread of the liquid indium tin alloy, forming a uniform indium tin film. If the second substrate layer is not preheated, the temperature of the first substrate will drop rapidly, causing the ITO film to solidify rapidly. Ultimately, the thickness of the ITO film becomes uncontrollable, which is not conducive to forming a uniform indium tin film.

[0056] In some embodiments, the pressure used for pressing is 2-8 kPa (exemplary pressures include 2 kPa, 3 kPa, 4 kPa, 5 kPa, 6 kPa, 7 kPa, 8 kPa, etc.), and the pressing duration is 1-5 min (exemplary durations include 1 min, 2 min, 3 min, 4 min, 5 min, etc.).

[0057] In this application, by laminating the second substrate layer, the liquid indium tin alloy can be uniformly spread under the action of heat and thermal force to form a uniform indium tin film. If the pressure used is too low or the lamination time is too short, the thickness of the ITO film will be too high, thus affecting the light transmittance of the film; if the pressure used is too high or the lamination time is too long, the ITO film will be too thin, resulting in poor electrical properties of the ITO film.

[0058] In some embodiments, the second base layer is removed by vertical lifting.

[0059] In this application, the second substrate layer is lifted and separated in a rapid vertical manner to avoid lateral slippage, thereby ensuring the complete transfer of the ITO film and the formation of a uniform metal network structure.

[0060] In some embodiments, the in-situ oxidation reaction is carried out in the presence of oxygen.

[0061] In this application, when the second base layer is removed, the laminated indium-tin alloy is oxidized in the presence of oxygen to form indium tin oxide (ITO). The in-situ oxidation reaction can be carried out in air or in oxygen.

[0062] In some embodiments, this application also provides an ITO thin film layer, wherein the method for preparing the ITO thin film layer includes: removing a first substrate layer from a conductive substrate layer prepared in the first aspect to obtain the ITO thin film layer.

[0063] In this application, the ITO film can be combined with the first substrate layer for the preparation of perovskite solar cells, or it can be peeled off separately for use or sale.

[0064] In some embodiments, this application provides a perovskite solar cell, such as Figure 2 As shown, the perovskite solar cell includes a flexible conductive transparent substrate layer, an electron transport layer 3, a perovskite absorption layer 4, a hole transport layer 5, and a metal electrode layer 6, which are stacked sequentially. The flexible conductive transparent substrate layer is the conductive substrate layer described above. The conductive substrate layer includes a first substrate layer 1 and an ITO thin film layer 2, which are stacked together. The ITO thin film layer 2 is connected to the electron transport layer 3.

[0065] In this application, a conductive substrate layer is applied to a perovskite solar cell. Based on the superior interfacial contact characteristics of the ITO thin film in the conductive substrate layer, the transfer of electrons from the perovskite absorber layer to the metal electrode layer is more efficient, reducing charge recombination and improving the fill factor and light conversion efficiency.

[0066] In this application, the conductive substrate layer prepared by the above method has good chemical and thermal stability, exhibits less performance degradation in multiple bending tests, and improves the service life of solar cells.

[0067] In some embodiments, the material of the electron transport layer includes any one of inorganic metal oxide materials, organic materials, inorganic silicon materials, or inorganic salt materials.

[0068] Among them, inorganic metal oxide materials include any one or a combination of at least two of SnO2, TiO2, ZnO, ZrO2, ZnO, MgO, zinc gallium oxide, zinc indium oxide, fluorine-doped tin oxide, or indium tin oxide.

[0069] Organic materials include C 60 Fullerene C 70 The combination of any one or at least two of the following: methyl (6,6)-phenyl-C61-butyrate (PCBM) or 4-(1',5'-dihydro-1'-methyl-2'H-(5,6)fullerene-C60-In-(1,9-c)pyrrole-2'-yl)benzamine chloride (CPMAC).

[0070] Inorganic silicon materials include any one or a combination of at least two of n-type monocrystalline silicon, n-type polycrystalline silicon, or n-type amorphous silicon.

[0071] Inorganic salt materials include Any one or at least two of them.

[0072] As a preferred technical solution of this application, the material of the electron transport layer includes C60, fullerene derivative (6,6)-phenyl-C61-butyrate methyl ester (PCBM), a combination of C60 and PCBM, a combination of PCBM and ZnO, a combination of ZnO and MgO, a combination of C60, PCBM and ZnO, a combination of PCBM, ZnO and MgO, and a combination of C60, PCBM, ZnO and MgO.

[0073] In some embodiments, the thickness of the electron transport layer is 3-50 nm (exemplary thicknesses include 3 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, etc.).

[0074] In some embodiments, the method for preparing the electron transport layer includes wet coating, sol-gel method, chemical vapor deposition, physical vapor deposition or plasma deposition.

[0075] In some embodiments, the perovskite absorber layer is made of a perovskite structure material having the general ABX3 structure.

[0076] Wherein: the A-site cation is usually a monovalent cation, including at least one of a monovalent metal cation and a monovalent organic cation; Monovalent metal cations are selected from cesium ions ( ), rubidium ions ( ), lithium-ion ( Sodium ions ), potassium ions ( ), thallium ions ( Any one or at least two of the following; Monovalent organic cations are selected from ammonium ions ( ), Methylamine ion (MA) ), ethylammonium ion ( ), dimethylamine ion ( ), trimethylammonium ion ( ), tetramethylammonium ion ( ), formamidinium ion (FA) ), methylformamidinium ion ( ), acetamidine ion ( ), guanidine ion ( Any one or at least two of the following.

[0077] The B-site cation is usually a divalent metal cation, selected from lead ions (…). ), tin ions ( or germanium ions ( Any combination of one or at least two of them.

[0078] The X-position anion is a halide anion, including bromide ions ( ), iodide ions ( ), chloride ions ( ), thiocyanate ion ( ), tetrafluoroborate ion ( ) or hexafluoroborate ion ( Any one or at least two of the following.

[0079] As a preferred technical solution in this application, the perovskite structural material is selected from... Any one or at least two of the following, wherein 0.1 <x<0.3,0.15<y<0.4。

[0080] In some embodiments, the perovskite structure comprises a first precursor compound and a second precursor compound. The first precursor compound has the chemical formula AX and includes any one or a combination of at least two of FAI (formamidine iodide), FABr (formamidine bromide), MAI (methylammonium iodide), MABr (methylammonium bromide), CsI (cesium iodide), and CsBr (cesium bromide); the second precursor compound has the chemical formula BX2 and includes... (lead iodide) (Lead bromide) (Stamenium iodide) Any one or at least a combination of two of (stannous bromide).

[0081] Understandably, the molar ratio of the first precursor compound to the second precursor compound is usually 1:1, in order to control the molar ratio of A ions, B ions, and X ions to be 1:1:3. In this way, after annealing, a perovskite structure with the general formula ABX3 can be obtained to form a perovskite layer.

[0082] In some embodiments, the perovskite layer preparation process includes: first forming a perovskite precursor layer, and then annealing and crystallizing it.

[0083] In some embodiments, the method of forming the perovskite precursor layer includes coating or vapor deposition.

[0084] Coating methods include slot coating, spraying, scraping, or spin coating.

[0085] When using the coating method, the perovskite structural material is mixed with a solvent to form a precursor solution, and the coating is performed using the precursor solution.

[0086] In the precursor solution, the molar concentration of the perovskite structure material is 1-2 mol / L (exemplary molar concentrations are 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, etc.).

[0087] The solvent in the precursor solution includes any one or a combination of at least two of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO), preferably a combination of DMF and NMP, a combination of DMF and DMI, or a combination of DMF and DMSO.

[0088] When the solvent is a combination of DMF and NMP, the volume ratio of DMF to NMP is 4:1; When the solvent is a combination of DMF and DMI, the volume ratio of DMF to DMI is 9:1; When the solvent is a combination of DMF and DMSO, the volume ratio of DMF to DMSO is 4:1.

[0089] In some embodiments, the annealing crystallization temperature is 90-150°C (exemplary temperatures are 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, etc.), and the time is 5-30 min (exemplary times are 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.).

[0090] In some embodiments, the hole transport layer is made of any one or a combination of at least two of transition metal oxides, small organic molecule materials, or polymer materials.

[0091] In some embodiments, the transition metal oxide includes nickel oxide (NiO) and / or copper oxide (CuO).

[0092] In some embodiments, the organic small molecule material is a SAM (self-assembled monolayer) material. SAM molecules can form a monolayer on the substrate surface through self-assembly, thereby playing a role in regulating interface properties, promoting charge transport, and reducing non-radiative recombination.

[0093] In some embodiments, SAM materials typically have a specific molecular structure. SAM molecules generally consist of anchoring groups, linking groups, and terminal groups. Anchoring groups typically contain polar atoms (such as oxygen, nitrogen, and sulfur) or active functional groups, capable of forming chemical bonds (such as covalent bonds, coordinate bonds), or strong hydrogen bonds with hydroxyl groups (-OH) or metal atoms on the TCO surface. Common types of anchoring groups include carboxyl groups (-COOH), phosphonic acid groups (... The anchoring groups (-OH, -SH) directly determine the stability of the SAM (e.g., water and heat resistance); if the bond is too weak, the SAM is easily detached, leading to device performance degradation.

[0094] Terminal groups typically contact the perovskite layer, and their main function is to regulate the interfacial energy level matching, wettability, and charge extraction efficiency between SAM and the perovskite layer. Common types of terminal groups are amino groups. ), cyano (-CN), alkyl ( () or conjugated groups, among which the common types of conjugated structures are benzene rings or thiophene.

[0095] Linking groups are the "backbone" of SAM molecules, connecting the anchoring group and the terminal group. They are typically composed of carbon chains, commonly C6-C18 alkyl chains. The length of the linking group determines the spatial distance between the anchoring group (TCO side) and the terminal group (perovskite side). The length and chemical properties of the linking group also affect the orderliness, conductivity, and steric hindrance of the SAM.

[0096] In some embodiments, the SAM material includes: [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACz), [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACz), 2-(3,6-dibromo-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), 2-(3,6-dichloro-9H-carbazole-9-yl)ethyl]phosphonic acid (Br-2PACz), and 2-(3,6-dichloro-9H-carbazole-9-yl)ethyl]phosphonic acid (BrO-2PACz). [4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Cl-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (F-2PACz), [4-(9H-carbazole-9-yl)ethyl]phosphonic acid (4PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz). [4-(3,6-dichloro-9H-carbazole-9-yl)butyl)phosphonic acid (Br-4PACz), [4-(3,6-dichloro-9H-carbazole-9-yl)butyl)phosphonic acid (Cl-4PACz), [4-(3,6-difluoro-9H-carbazole-9-yl)butyl)phosphonic acid (F-4PACz), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid (4PADCB), [4-(2,7-dibromo-9,9-dimethylacridin-10(9-hydro)-yl)butyl]phosphonic acid (2Br-4DMAcPA), 4- Sodium phenylbutyrate (4-PBA), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanovinyl)phosphonic acid (MPA-CPA), [2-(3,7-dibromo-10H-phenthiazin-10-yl)ethyl]phosphonic acid (Br-2EPT), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), or 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline] (TAPC) or any one or a combination of at least two of these.

[0097] In some embodiments, the method for preparing a hole transport layer includes: A1. Mix the SAM material with a solvent and stir at room temperature in a glove box under a nitrogen atmosphere until completely dissolved to obtain a hole transport layer solution. The concentration of the SAM material in the hole transport layer solution is 0.1-3 mg / mL (exemplary concentrations are 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, etc.). A2. In a glove box under a nitrogen atmosphere, the hole transport layer solution is coated to obtain a wet film; then it is placed on a hot plate at 80-120℃ (exemplary temperatures are 80℃, 90℃, 100℃, 110℃, 120℃, etc.) and heated and annealed for 5-20 minutes (exemplary times are 5 minutes, 10 minutes, 15 minutes, 20 minutes, etc.) to form a hole transport layer.

[0098] In some embodiments, the material of the metal electrode layer includes any one or a combination of at least two of copper (Cu), aluminum (Al), silver (Ag), nickel (Ni), cobalt (Co), gold (Au), molybdenum (Mo), or chromium (Cr), preferably a combination of Ag, copper, Cu, and Al, a combination of Ag and Ni, a combination of Co and Au, a combination of Mo and Cr, or a combination of Cu, Al, Ag, Ni, Co, Au, Mo, and Cr.

[0099] In some embodiments, the method for preparing the metal electrode layer includes vapor deposition, screen printing, electroplating, laser technology, physical vapor deposition (PVD) or inkjet printing.

[0100] In some embodiments, the thickness of the metal electrode layer is 0.1-20 μm (exemplary thicknesses include 0.1 μm, 1 μm, 3 μm, 5 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, etc.).

[0101] The following section will conduct performance tests on the structure or fabrication method of the ITO thin film provided in the embodiments of this application, as well as related comparative examples.

[0102]

Example 1

[0103] S2. Take two polyimide (PI) films with a size of 20 mm × 20 mm and a thickness of 170 μm, and use hot ethanol at 70°C for ultrasonic cleaning to thoroughly remove surface contaminants. These are referred to as the first substrate layer and the second substrate layer, respectively.

[0104] S3. After the substrate has dried, a glass Pasteur pipette is used to transfer the prepared In-Sn alloy droplet (approximately 3 mm in diameter) to the central region of the first substrate layer. Subsequently, the second substrate layer is preheated to 200°C and quickly aligned and pressed onto the droplet, allowing the liquid alloy to spread uniformly between the two substrate layers under heat and pressure. The entire pressing process is carried out in air, applying a pressure of approximately 4 kPa for 2 minutes.

[0105] S4. After lamination, the second substrate layer is lifted and separated quickly and vertically to avoid lateral slippage, ensuring complete transfer of the alloy film and the formation of a uniform metal planar structure. After the system cools to room temperature, In-Sn is oxidized in contact with air to generate a flexible ITO film with a thickness of approximately 400 nm, resulting in a conductive substrate layer.

[0106] This embodiment also provides a method for preparing a perovskite solar cell, including: (1) Preparation of flexible conductive transparent substrate: The conductive substrate prepared above is transferred and firmly attached to a hard glass substrate of the same size to form a flexible conductive transparent substrate; (2) Preparation of the electron transport layer: The purchased tin dioxide colloidal solution was diluted with pure water. The dilution ratio was 1:4 (by volume) of SnO2 to pure water in an aqueous solution of tin dioxide. 100 μL of the diluted solution was dropped onto the flexible conductive transparent substrate layer prepared by In-Sn alloy droplet imprinting, and the film was formed by spin coating at 4000 rpm for 30 s. The sample was then annealed on a hot plate at 150 ℃ for 30 min and allowed to cool naturally to room temperature before use. (3) Preparation of the perovskite absorber layer: First, 70 μL of PbI2 solution (1.5 mol / L, DMF:DMSO = 9:1) was dropped onto the SnO2-modified substrate and spin-coated at 1500 rpm for 30 seconds. Then, the PbI2 film was transferred to a 70 ℃ hot plate for annealing for 1 min. After cooling to room temperature, a cation solution (FAI / MABr / MACl = 90 / 6.4 / 9 mg / mL, solvent: IPA) was spin-coated onto the PbI2 layer at 2000 rpm for 30 s. Finally, the sample was placed on a 150 ℃ plate hot plate for annealing for 15 min to form a perovskite film. The entire process was carried out in a nitrogen atmosphere. (4) Preparation of the hole transport layer: 74.5 mg Spiro-OMeTAD was weighed and dissolved in 1 mL of chlorobenzene, and stirred at room temperature for 3 h until completely dissolved. Then, 29.0 μL of 4-tert-butylpyridine (tBP) and 17.8 μL of lithium salt solution (LiTFSI concentration of 520 mg / mL, dissolved in acetonitrile) were added, and stirring was continued for 1 h to ensure uniform mixing. Before use, the solution was filtered through a 0.22 μm PTFE membrane to remove insoluble impurities. After the perovskite film cooled to room temperature, 60 μL of the above solution was dropped onto its surface, and spin-coated at 3000 rpm for 30 s to form a hole transport layer. After spin-coating, the sample was placed in a light-proof, dry electronic dehumidifier cabinet and aged for more than 24 h to promote the oxidation of Spiro-OMeTAD and improve its hole conductivity. (5) Preparation of the metal electrode layer: Weigh approximately 0.3 g of gold particles, place them in a tungsten boat, and fix the sample in the sample chamber of the vapor deposition machine. After closing the vapor deposition machine door, turn on the mechanical pump and the fore-stage valve in sequence. Start the molecular pump when the gas pressure drops below 2 Pa. Wait until the gas pressure in the sample chamber drops to 10 Pa. -4 Once the pressure is below Pa, turn on the evaporation power supply and evaporation rotation function, and adjust the evaporation source current to control the evaporation rate within the range of 1.5–2 Å / s. When the film thickness gauge shows 1000 Å, turn off the evaporation power supply and evaporation rotation device in sequence, then turn off the molecular pump and the fore-stage valve, and finally turn off the mechanical pump, open the vent valve, and remove the sample.

[0107] (6) Removal of glass substrate: Finally, peel off the adhered hard glass support substrate to obtain a complete flexible perovskite solar cell.

[0108]

Example 2

[0109] The fabrication method of the flexible perovskite solar cell in Example 2 is the same as that in Example 1.

[0110]

Example 3

[0111] The fabrication method of the flexible perovskite solar cell in Example 3 is the same as that in Example 1.

[0112]

Example 4

[0113] The fabrication method of the flexible perovskite solar cell in Example 4 is the same as that in Example 1.

[0114]

Example 5

[0115] The fabrication method of the flexible perovskite solar cell in Example 5 is the same as that in Example 1.

[0116]

Example 6

[0117] The fabrication method of the flexible perovskite solar cell in Example 6 is the same as that in Example 1.

[0118]

Example 7

[0119] The fabrication method of the flexible perovskite solar cell in Example 7 is the same as that in Example 1.

[0120] Comparative Example 1 This comparative example provides a conductive substrate layer, which is prepared by the following method: Cleaning of commercial flexible ITO substrates: A substrate with dimensions of 20 mm × 20 mm and a sheet resistance of... Commercial flexible ITO films were bonded to a rigid glass substrate of the same size to enhance mechanical stability. Subsequently, the surface of the flexible ITO film was treated with oxygen plasma for approximately 5 minutes to remove organic contaminants and increase surface energy, thereby improving the wettability and adhesion of subsequent films.

[0121] The fabrication method of the flexible perovskite solar cell in Comparative Example 1 is the same as that in Example 1.

[0122] Figure 3 The images shown are scanning electron microscope (SEM) images of the perovskite absorber layer surface during the process of obtaining flexible perovskite solar cells in Example 2 and Comparative Example 1. The left side is the SEM image of Comparative Example 1, and the right side is the SEM image of Example 2. By comparison, it can be seen that the perovskite grain size deposited on the ITO thin film prepared by In-Sn alloy droplet imprinting in Example 2 is larger.

[0123] Figure 4 The image shown is a scanning electron microscope (SEM) image of a side cross-section of the flexible perovskite solar cell prepared in Example 3. From the side view, it can be seen that the thickness of the ITO thin film is approximately 416.8 nm, the electron transport layer is very thin, the perovskite absorber layer is approximately 744.2 nm, the hole transport layer is approximately 163.8 nm, and the metal electrode layer is approximately 74.43 nm. This indicates that the ITO thin film prepared by the In-Sn alloy droplet imprinting method of this application has good density and is free of pores.

[0124] Figure 5 The above are IV curves of the flexible perovskite solar cells prepared in Examples 1-4 and Comparative Example 1. Figure 5 It is known that the ITO thin film prepared by droplet imprinting of the In-Sn alloy of this application has better cell performance in flexible perovskite solar cell applications. Among them, the ITO thin film prepared in Example 3 (indium to tin atomic ratio 92:8) has the best performance.

[0125] Figure 6 The graphs show the bending resistance curves of the flexible perovskite solar cells obtained in Example 3 and Comparative Example 1, with a bending radius of 8 mm. Figure 6 It can be seen that the flexible solar cells prepared by the In-Sn alloy droplet imprinting of this application have better bending resistance.

[0126] The short-circuit current, open-circuit voltage, fill factor, and light conversion efficiency of the solar cells obtained in Examples 1-7 and Comparative Example 1 were tested. Table 1 Performance test results of perovskite solar cells obtained in Examples 1-7 and Comparative Example 1

[0127] A comparison of Examples 1-7 and Comparative Example 1 shows that the perovskite solar cells of Examples 1-9 prepared by the imprinting method in this application all exhibit superior photovoltaic performance, with efficiencies all exceeding 22%. Among them, Example 3 demonstrates the best overall performance, with a photoelectric conversion efficiency of 22.8%, an improvement of nearly 3 percentage points compared to the comparative example. This significant improvement is mainly due to the increase in open-circuit voltage from 1.137 V to 1.169 V and the substantial increase in fill factor from 77.3% to 82.8%. The short-circuit current density of each group of samples is slightly higher than that of Comparative Example 1, indicating that the light absorption capacity of the ITO thin film prepared using the method of this application is not significantly affected.

[0128] The comparison of Examples 1-7 shows that the efficiency of perovskite solar cells first increases and then decreases with the thickness of the ITO film. This indicates that both excessively thin and excessively thick ITO films will reduce the efficiency of the cells.

[0129] Therefore, by optimizing the indium-tin ratio and adjusting the pressure used in the lamination process, the charge collection and transport capabilities can be effectively improved, and the series resistance and recombination loss of perovskite solar cells can be reduced.

[0130] This application embodiment can also provide a photovoltaic module (not shown), which includes the perovskite cell described above. The HBC cell can be connected in series and / or in parallel with one or more other perovskite cells in a preset manner. Multiple cells can form a cell string, and adjacent cells can be connected together by string welding.

[0131] This application provides a photovoltaic system including the photovoltaic modules described in any of the above embodiments. The advantages of the aforementioned photovoltaic modules are also present in this photovoltaic system, and will not be repeated here. The application fields of the aforementioned photovoltaic system are wide, not limited to photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants, but also including various devices and apparatuses that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system are not limited to these; that is, the photovoltaic system can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic modules; for example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0132] It should be noted that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. The directional terms "inner" and "outer" refer to the inside or outside relative to the outline of the component itself. For example, if a device in the drawings is inverted, a device described as "above" or "on top of" other devices or structures will subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0133] It should also be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this application refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0134] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0135] It should also be noted that the above are merely preferred embodiments of this application and do not limit the scope of patent protection of this application. Any equivalent structural or procedural changes made using the content of this application’s specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A method for preparing a conductive substrate layer, characterized in that, The method for preparing the conductive substrate layer includes the following steps: Liquid indium tin alloy is added to one side of the first substrate layer. Then, a second substrate layer is placed on top of the liquid indium tin alloy and pressed together. After that, the second substrate layer is removed. The pressed indium tin alloy undergoes an in-situ oxidation reaction to obtain a conductive substrate layer.

2. The preparation method according to claim 1, characterized in that, The materials of the first substrate layer and the second substrate layer are each independently selected from any one or a combination of at least two of polyimide, polyethylene terephthalate, polyethylene naphthalate, or metal foil; The thickness of the first substrate layer and the second substrate layer are each independently 100-300 μm.

3. The preparation method according to claim 1, characterized in that, The preparation method of the liquid indium-tin alloy includes: mixing indium and tin at 200-250℃ for 20-40 min to obtain the liquid indium-tin alloy; With the sum of the number of indium and tin atoms being 100, the ratio of the number of indium and tin atoms is (88-98):(12-2); The liquid indium-tin alloy is added dropwise; The diameter of the added droplets is 3-5 mm.

4. The preparation method according to claim 1, characterized in that, The second base layer is preheated before lamination; The preheating temperature is 180-200℃.

5. The preparation method according to claim 1, characterized in that, The pressure used for the pressing is 2-8 kPa, and the pressing time is 1-5 min.

6. The preparation method according to claim 1, characterized in that, The second base layer was removed by vertical lifting. The in-situ oxidation reaction is carried out under the action of oxygen.

7. A conductive substrate layer is prepared by the preparation method according to any one of claims 1-6; The conductive substrate layer includes a first substrate layer and an ITO thin film layer located on one side surface of the first substrate layer; The thickness of the ITO thin film layer is 100-500 nm.

8. An ITO thin film layer, characterized in that, The method for preparing the ITO thin film layer includes: removing the first substrate layer from the conductive substrate layer prepared according to any one of claims 1-6 to obtain the ITO thin film layer.

9. A perovskite battery, characterized in that, The perovskite solar cell comprises a flexible conductive transparent substrate layer, an electron transport layer, a perovskite absorption layer, a hole transport layer, and a metal electrode layer stacked sequentially; the flexible conductive transparent substrate layer is a conductive substrate layer prepared by the preparation method according to any one of claims 1-6.

10. A photovoltaic module, characterized in that, The photovoltaic module includes the perovskite cell as described in claim 9.

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