Hole transport layer precursor solution, hole transport layer and preparation method thereof, and perovskite solar cell

Abstract

The embodiments of the present application provide a hole transport layer precursor solution, a hole transport layer and a preparation method thereof, and a perovskite solar cell, and relate to the technical field of perovskite solar cells. The hole transport layer precursor solution includes: a hole transport layer material, a phenolic antioxidant, and an organic solvent; the structure of the phenolic antioxidant includes a benzene ring, a phenolic hydroxyl group, and a butyl group. Phenolic antioxidants are doped into the hole transport layer precursor solution. Under the joint action of the benzene ring, the phenolic hydroxyl group, and the butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, and the process stability of the hole transport layer can be improved, which is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be improved. In the process of large-area coating of the hole transport layer precursor solution, the film formation of the hole transport layer can be optimized, which is helpful to obtain a higher photoelectric conversion efficiency.

Description

Technical Field

[0001] The present application relates to the technical field of perovskite solar cells, and in particular to a hole transport layer precursor solution, a hole transport layer and a preparation method thereof, and a perovskite solar cell. Background Art

[0002] Perovskite solar cells (PSCs), as an emerging photovoltaic technology, have attracted widespread attention in laboratories and industry in recent years. Their core advantages lie in high efficiency, low cost and relatively simple preparation process. Perovskite materials are a type of composite materials with ABX3 structure, where A is an organic or inorganic cation and B is a metal cation (such as Pb 2+ ), X is a halogen anion (such as C – ,Br – , I – ). These materials have excellent photoelectric conversion efficiency, wide spectral response range, adjustable band gap and flexible material design, making them ideal for high-efficiency photovoltaic devices. Compared with normal structure perovskite solar cells, inverted structure perovskite solar cells often show better humidity and thermal stability, and the current hysteresis effect is usually weaker, which is manifested as a faster response speed, which means that the performance of inverted structure perovskite solar cells in actual photovoltaic devices will be closer to the ideal state and the efficiency will be more stable.

[0003] At present, the hole transport layer in both the normal-structure perovskite solar cells and the inverted-structure perovskite solar cells is formed by a hole transport layer precursor solution. The hole transport layer precursor solution with ethanol (EtOH) as the main solvent evaporates quickly. When applied on a large scale, the hole transport layer precursor solution to be used is prone to uncontrollable deterioration in the air environment, affecting the film formation and process stability of the hole transport layer, and further affecting the photoelectric conversion efficiency of the perovskite solar cell.

[0004] 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

[0005] The embodiments of the present application provide a hole transport layer precursor solution, a hole transport layer and a preparation method thereof, and a perovskite solar cell that can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain higher photoelectric conversion efficiency, so as to solve or alleviate the technical problems raised above.

[0006] To achieve the above purpose, this application adopts the following technical solutions: A hole transport layer precursor solution, comprising: a hole transport layer material, a phenolic antioxidant, and an organic solvent; The structure of the phenolic antioxidant includes a benzene ring, a phenolic hydroxyl group and a butyl group.

[0007] In some embodiments, the phenolic antioxidant has 1-2 phenolic hydroxyl groups on the benzene ring; The benzene ring of the phenolic antioxidant is provided with 1-2 butyl groups.

[0008] In some embodiments, when two phenolic hydroxyl groups are arranged on the benzene ring of the phenolic antioxidant, the positional relationship between the phenolic hydroxyl groups is para; And / or, when two butyl groups are arranged on the benzene ring of the phenolic antioxidant, the positional relationship between the butyl groups is meta.

[0009] In some embodiments, the phenolic antioxidant includes one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, and tert-butylhydroquinone.

[0010] In some embodiments, the organic solvent includes one or more of ethanol, 2-methoxyethanol, N,N-dimethylformamide, acetonitrile, isopropanol, and chlorobenzene.

[0011] In some embodiments, the concentration of the phenolic antioxidant is 10 to 1000 ppm; And / or, the concentration of the hole transport layer material is 0.5-2.0 mg / ml.

[0012] The present invention also provides a method for preparing a hole transport layer, comprising the following steps: coating a hole transport layer precursor solution on a substrate and performing an annealing treatment to obtain a hole transport layer; The hole transport layer precursor solution comprises a hole transport layer material, a phenolic antioxidant, and an organic solvent; the structure of the phenolic antioxidant comprises a benzene ring, a phenolic hydroxyl group, and a butyl group.

[0013] In some embodiments, the annealing treatment is performed in an inert atmosphere, the annealing temperature is 80-100° C., and the annealing time is 5-10 min.

[0014] The embodiment of the present application also provides a hole transport layer, wherein the hole transport layer is formed by the hole transport layer precursor solution as described above; Alternatively, the hole transport layer is prepared by the method as described above.

[0015] The embodiment of the present application also provides a perovskite solar cell, comprising: a substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer stacked in sequence; The hole transport layer is formed from the hole transport layer precursor solution as described above; Alternatively, the hole transport layer is prepared by the method as described above.

[0016] In some embodiments, the perovskite light absorbing layer is formed from a perovskite precursor solution; The perovskite precursor solution comprises: a perovskite material, a phenolic antioxidant, and a solvent.

[0017] In some embodiments, the concentration of the phenolic antioxidant in the perovskite precursor solution is 100-1000 ppm.

[0018] An embodiment of the present application also provides a photovoltaic cell assembly, including the above-mentioned perovskite solar cell.

[0019] The above technical solution adopted in the embodiment of the present application may have the following advantages: By doping the hole transport layer precursor solution with a phenolic antioxidant, the combined action of the benzene ring, phenolic hydroxyl group and butyl group can improve the wettability of the hole transport layer to the substrate, optimize the film formation of the hole transport layer, enhance the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency; under the combined action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively enhanced, and in the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the uncontrollable deterioration of the hole transport layer precursor solution, optimize the film formation of the hole transport layer, enhance the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.

[0021] Figure 1 It is a schematic diagram of the structure of a perovskite solar cell provided in an embodiment of the present application.

[0022] Description of reference numerals: 1. Substrate; 2. Hole transport layer; 3. Perovskite light absorption layer; 4. Passivation layer; 5. Electron transport layer; 6. Buffer layer; 7. Electrode. DETAILED DESCRIPTION

[0023] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0024] 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 can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present disclosure, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not mean that the present disclosure necessarily has the first element, component, region, layer or part.

[0025] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each 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 range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.

[0028] The present application aims to provide a hole transport layer precursor solution, a hole transport layer and a preparation method thereof, and a perovskite solar cell. A phenolic antioxidant is doped in the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and it is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of large-area coating of the hole transport layer precursor solution, it is helpful to prevent the uncontrollable deterioration of the hole transport layer precursor solution, and it can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency. ‌

[0029] Below, exemplary embodiments of the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.

[0030] The embodiment of the present application provides a hole transport layer precursor solution, including: a hole transport layer material, a phenolic antioxidant, and an organic solvent; The structure of phenolic antioxidants includes benzene ring, phenolic hydroxyl group and butyl group.

[0031] In the embodiment of the present application, the structure of the phenolic antioxidant includes a benzene ring, a phenolic hydroxyl group, and a butyl group, wherein the butyl group can be selected from one or more of a normal butyl group and a tert-butyl group. Under the joint action of the benzene ring, the phenolic hydroxyl group, and the butyl group, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and a higher photoelectric conversion efficiency can be obtained. It should be noted that the hole transport layer precursor solution in the embodiment of the present application is used to form a hole transport layer, which is applicable to conventional perovskite solar cells, and is also applicable to trans-structured perovskite solar cells, and the hole transport layer is also applicable to other types of batteries provided with a hole transport layer.

[0032] In the embodiment of the present application, the hole transport layer precursor solution is used to form the hole transport layer; the preparation method of the hole transport layer may include one or more of slit coating, spin coating, and blade coating. The thickness of the hole transport layer may be 1-100 nm (for example, 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 60 nm, 80 nm, 100 nm).

[0033] In the embodiment of the present application, the hole transport layer material includes an organic hole transport material, an inorganic hole transport material, and a self-assembled monolayer material (Self-Assembled Monolayer, referred to as SAM). More specifically, the hole transport material may include one or more of [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2PACZ for short), (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid (MeO-2PACZ for short), (4-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Me-4PACZ for short), (2-(4-(bis(4-methoxyphenyl)amino)phenyl)-1-cyanotitanyl)phosphonic acid (MPA-CPA for short), (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)yl)butyl)phosphonic acid (DMAcPA for short), PEDOT:PSS (poly-3,4-ethylenedioxythiophene:polystyrenesulfonate), NiOx, and CuSCN. In addition, a suitable organic solvent may be selected according to the hole transport layer material.

[0034] In the embodiment of the present application, doping a phenolic antioxidant into the hole transport layer precursor solution can also effectively filter ultraviolet light in the UVb band (a band with a wavelength between 280 and 320 nanometers), reduce the irreversible damage of UVb band light to the perovskite light absorption layer, and improve the stability of the solar cell.

[0035] In the embodiments of the present application, doping a phenolic antioxidant into a hole transport layer precursor solution can be used as a universal technology for the industrial preparation of large-area perovskite solar cells. Without affecting the main components and the structure of key active substances, the long-term environmental stability and process repeatability of the hole transport layer precursor solution can be improved, thereby achieving an increase in the yield rate of solar cells.

[0036] In the embodiment of the present application, a phenolic antioxidant is doped into the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and it is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, which can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0037] In some embodiments, the phenolic antioxidant has 1-2 phenolic hydroxyl groups on the benzene ring; Phenolic antioxidants have 1-2 butyl groups on the benzene ring.

[0038] In the embodiment of the present application, when the number of phenolic hydroxyl groups on the benzene ring is 1-2 and the number of butyl groups is 1-2, the film-forming quality and process stability of the hole transport layer can be greatly improved. Phenolic antioxidants (including benzene rings, phenolic hydroxyl groups and butyl groups) are doped in the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl groups and butyl groups, the wettability of the hole transport layer to the substrate can be improved, the film-forming condition of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and a higher photoelectric conversion efficiency can be obtained; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of coating the hole transport layer precursor solution over a large area, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, which can optimize the film-forming condition of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0039] In some embodiments, when two phenolic hydroxyl groups are arranged on the benzene ring of the phenolic antioxidant, the positional relationship between the phenolic hydroxyl groups is para; And / or, when two butyl groups are provided on the benzene ring of the phenolic antioxidant, the positional relationship between the butyl groups is meta.

[0040] In the embodiment of the present application, when two phenolic hydroxyl groups are provided on the benzene ring, the positional relationship between the phenolic hydroxyl groups is para; and / or, when two butyl groups are provided on the benzene ring, the positional relationship between the butyl groups is meta, which can further improve the film quality and process stability of the hole transport layer. Phenolic antioxidants are doped in the hole transport layer precursor solution. Under the joint action of the benzene ring, the phenolic hydroxyl group and the butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and a higher photoelectric conversion efficiency can be obtained; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of applying the hole transport layer precursor solution over a large area, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, and the film formation of the hole transport layer can be optimized, and the process stability of the hole transport layer can be improved, which can help obtain a higher photoelectric conversion efficiency.

[0041] In some embodiments, the phenolic antioxidant includes one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, and tert-butylhydroquinone. These phenolic antioxidants have good antioxidant properties, effectively remove harmful free radicals, and can further improve the wettability of the hole transport layer to the substrate and optimize the film formation of the hole transport layer.

[0042] In the present embodiment, butylated hydroxyanisole (BHA) is also known as tert-butyl-4-hydroxyanisole, and its chemical formula is C 11 H 16 O2, there are two isomers: 3-BHA and 2-BHA; that is, butylated hydroxyanisole can be 3-BHA, butylated hydroxyanisole can also be 2-BHA, and butylated hydroxyanisole can also be a mixture of 3-BHA and 2-BHA.

[0043] Among them, the structural formula of 3-BHA is: ; The structural formula of 2-BHA is: ; The structural formula of tert-butylhydroquinone is: ; The structural formula of 2,6-di-tert-butyl-p-cresol is: .

[0044] In the embodiment of the present application, a phenolic antioxidant is doped into the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and it is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, which can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0045] In some embodiments, the organic solvent includes one or more of ethanol, 2-methoxyethanol, N,N-dimethylformamide, acetonitrile, isopropanol, and chlorobenzene.

[0046] In the embodiments of the present application, since different solvent compositions differ in evaporation rate, solution viscosity, and wettability with the substrate, and different solvents also have large differences in stability in the air environment, optimizing the type of organic solvent and doping the hole transport layer precursor solution with a phenolic antioxidant can narrow the gap in process repeatability between different solvent systems, optimize the film formation of the hole transport layer, and improve the process stability of the hole transport layer, which is beneficial to improving the photoelectric conversion efficiency of solar cells.

[0047] In some embodiments, the concentration of the phenolic antioxidant is 10 to 1000 ppm (e.g., 10 ppm, 100 ppm, 300 ppm, 500 ppm, 700 ppm, 900 ppm, 1000 ppm); And / or, the concentration of the hole transport layer material is 0.5-2.0 mg / ml (e.g., 0.5 mg / ml, 0.7 mg / ml, 0.9 mg / ml, 1.2 mg / ml, 1.5 mg / ml, 1.7 mg / ml, 2.0 mg / ml).

[0048] In the embodiments of the present application, the concentration of the phenolic antioxidant is controlled, and under the joint action of the benzene ring, the phenolic hydroxyl group and the butyl group, the wettability of the hole transport layer to the substrate can be effectively improved, which is beneficial to improving the film-forming quality of the hole transport layer and enhancing the process stability of the hole transport layer; in addition, when the perovskite light-absorbing layer is subsequently prepared, it is beneficial to improve the coating uniformity and film quality of the perovskite wet film, which helps to obtain a higher photoelectric conversion efficiency.

[0049] In the embodiments of the present application, the concentration of the hole transport layer material is controlled to avoid agglomeration of the hole transport layer material on the substrate and uneven distribution of the hole transport layer material, which is beneficial to improving the film quality of the hole transport layer. When the perovskite light absorbing layer is subsequently prepared, it is beneficial to improve the coating uniformity and film quality of the perovskite wet film, which helps to obtain a higher photoelectric conversion efficiency.

[0050] The present invention also provides a method for preparing a hole transport layer, comprising the following steps: coating a hole transport layer precursor solution on a substrate and performing an annealing treatment to obtain a hole transport layer; The hole transport layer precursor solution includes hole transport layer materials, phenolic antioxidants, and organic solvents; the structure of the phenolic antioxidants includes benzene rings, phenolic hydroxyl groups, and butyl groups.

[0051] In the embodiment of the present application, a phenolic antioxidant is doped into the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and it is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, which can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0052] In some embodiments, the annealing treatment is carried out in an inert atmosphere, the annealing temperature is 80-100°C (e.g., 80°C, 85°C, 90°C, 95°C, 100°C), and the annealing time is 5-10 min (e.g., 5 min, 6 min, 7 min, 8 min, 9 min, 10 min).

[0053] In the embodiment of the present application, the annealing treatment can be performed by hot plate annealing or oven annealing; the annealing treatment is performed in an inert atmosphere (such as nitrogen) to prevent oxidation. Controlling the annealing process can improve the film quality of the hole transport layer and help obtain a higher photoelectric conversion efficiency. Preferably, when the annealing temperature is 85-95°C, the film quality of the hole transport layer can be further improved, which helps obtain a higher photoelectric conversion efficiency.

[0054] The embodiment of the present application also provides a hole transport layer, wherein the hole transport layer is formed by the hole transport layer precursor solution as described above; Alternatively, the hole transport layer is prepared by the method as described above.

[0055] In the embodiment of the present application, a phenolic antioxidant is doped into the hole transport layer precursor solution. Under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and it is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved. In the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, which can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0056] The embodiment of the present application also provides a perovskite solar cell, comprising: a substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer stacked in sequence; The hole transport layer is formed from the hole transport layer precursor solution as described above; Alternatively, the hole transport layer is prepared by the method as described above.

[0057] In an embodiment of the present application, the substrate includes but is not limited to indium tin oxide (ITO) transparent conductive glass, fluorine-doped tin oxide (FTO) transparent conductive glass, tungsten-doped indium oxide (IWO) transparent conductive glass, and aluminum-doped zinc oxide (AZO) transparent conductive glass. Before preparing the hole transport layer, the substrate can be cleaned, laser etched, and ultraviolet treated. The step of cleaning the substrate may include: placing the substrate in an ultrasonic cleaning instrument, ultrasonically cleaning with deionized water, isopropanol, and ethanol, respectively, the cleaning time for each step is 20-40 minutes (for example, 20 minutes, 30 minutes, 40 minutes), and then drying with nitrogen after cleaning. The step of ultraviolet treatment of the substrate may include: treating the substrate with a UV-zone, wherein the treatment time is 20-40 minutes (for example, 20 minutes, 30 minutes, 40 minutes).

[0058] In the embodiment of the present application, the preparation method of the hole transport layer can be: applying the hole transport layer precursor solution to the surface of the substrate by a slit coating method to obtain the hole transport layer. The hole transport layer precursor solution is configured by mixing the hole transport material and the organic solvent, dissolving the hole transport material, and adding an appropriate amount of BHT as a stabilizer and additive to configure the hole transport layer precursor solution; applying the hole transport layer precursor solution to the upper surface of the substrate to form a wet film, and then performing an annealing treatment to remove the solvent to form the hole transport layer.

[0059] In an embodiment of the present application, the preparation method of the perovskite light absorbing layer may be: applying a perovskite precursor solution to the surface of the hole transport layer by a slit coating method to obtain the perovskite light absorbing layer. The perovskite precursor solution is prepared by mixing the perovskite material and the organic solvent, dissolving the perovskite material, and adding an appropriate amount of phenolic antioxidant as a stabilizer and additive to prepare the perovskite precursor solution; applying the perovskite precursor solution to the upper surface of the hole transport layer to form a perovskite wet film, and then performing an annealing treatment to remove the solvent to form the perovskite light absorbing layer.

[0060] In the embodiment of the present application, a passivation layer may also be included. The material of the passivation layer may be one or more of 2-thiopheneethylamine hydrochloride (TEACl), 1,4-phenylenediamine hydroiodide (PDADI), and phenylethylamine iodide (PEAI), and the thickness of the passivation layer is 1-3 nm (e.g., 1 nm, 2 nm, 3 nm). The substrate of the passivation layer after evaporation is heated at 100-150°C (e.g., 100°C, 120°C, 150°C) for 3-15 min (e.g., 3 min, 6 min, 10 min). The passivation layer may be prepared by vacuum evaporation, magnetron sputtering, atomic layer deposition, and the like. When vacuum evaporation is used, the evaporation rate may be 0.3-1 Å / s (e.g., 0.3 Å / s, 0.5 Å / s, 1 Å / s).

[0061] In the embodiment of the present application, the material of the electron transport layer may include PCBM ([6,6]-phenyl-C 71 -isomethyl butyrate), TiO2, SnO2, ZnO2, Al2O3, C 60 and ICBA (Indene-C 60 The electron transport layer can be prepared by vacuum evaporation, magnetron sputtering, atomic layer deposition and the like. When the vacuum evaporation method is used, the evaporation rate can be 0.2Å / s, the evaporation time is 1500s, and the evaporation thickness is 30nm.

[0062] In the embodiment of the present application, a buffer layer may also be included. The material of the buffer layer is BCP (2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline), MoO x The buffer layer can be prepared by vacuum evaporation, magnetron sputtering, atomic layer deposition and the like. When the vacuum evaporation method is used, the evaporation rate can be 0.1Å / s, the evaporation time is 1500s, and the evaporation thickness is 15nm.

[0063] In the embodiment of the present application, an electrode may also be included, and the material of the electrode is one of Ag, Au, Cu, ITO, IZO, AZO and IWO. The electrode may be prepared by thermal evaporation, vacuum evaporation, sputtering, atomic layer deposition, 3D printing, screen printing, inkjet printing and the like. When the vacuum evaporation method is used, the evaporation rate may be 1Å / s, the evaporation time may be 2000s, and the final evaporation thickness may be 200nm.

[0064] In an embodiment of the present application, the structure of the perovskite solar cell may be that the perovskite solar cell includes: a substrate, a hole transport layer, a perovskite light absorbing layer, a passivation layer, an electron transport layer, a buffer layer, and an electrode stacked in sequence.

[0065] In the embodiment of the present application, the above-mentioned hole transport layer is used, and the film-forming quality of the hole transport layer is high. When the perovskite light-absorbing layer is subsequently prepared, it is beneficial to improve the coating uniformity and film quality of the perovskite wet film, and help to obtain a higher photoelectric conversion efficiency.

[0066] In some embodiments, the perovskite light absorbing layer is formed from a perovskite precursor solution; The perovskite precursor solution includes: a perovskite material, a phenolic antioxidant, and a solvent.

[0067] In the embodiment of the present application, by adding phenolic antioxidants to the perovskite precursor solution, under the joint action of benzene ring, phenolic hydroxyl group and butyl group, the wettability of the perovskite precursor solution to the hole transport layer can be effectively improved, and the coating uniformity of the perovskite wet film and the film quality of the perovskite light absorbing layer can be improved. Adding phenolic antioxidants to the perovskite precursor solution can effectively improve the long-term thermal stability and anti-photooxidation ability of the perovskite precursor solution. The long-term stability of the perovskite precursor solution in the air environment is a key factor in improving the repeatability of the perovskite light absorbing layer process and the device yield. Therefore, adding phenolic antioxidants to the perovskite precursor solution is beneficial to improving the long-term stability of perovskite solar cells. In addition, the ultraviolet absorption wavelength of phenolic antioxidants containing benzene rings, phenolic hydroxyl groups, and butyl groups is about 280 to 310 nm. After adding phenolic antioxidants containing benzene rings, phenolic hydroxyl groups, and butyl groups to the perovskite light-absorbing layer, the ability of the perovskite light-absorbing layer film to resist ultraviolet radiation can be significantly improved, which is beneficial to improving the long-term stability of perovskite solar cells.

[0068] In the embodiment of the present application, the perovskite material is an ABX3 structure; A is usually a formamidinium cation (FA + ), methylammonium cation (MA + ) and cesium ions (Cs + ), B is usually a divalent cation such as lead ion (Pb 2+ ) and tin ions (Sn 2+) one or more, X is usually a halogen anion such as iodide ion (I – ) and (Br – ) or more; wherein the concentration of B is 1 mol / L to 2 mol / L. In the embodiment of the present application, preferably, when a large-area perovskite film is prepared by a slit coating method, the selected Pb 2+ The concentration does not exceed 2 mol / L to obtain a suitable film thickness and a high film quality. The thickness of the perovskite light absorbing layer can be 300-800nm.

[0069] In the embodiment of the present application, preferably, the solvent in the perovskite precursor solution can be one or more of N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO) and acetonitrile (ACN). When preparing the perovskite light absorbing layer, the above solvents can be used to dissolve the perovskite material and the organic cations, which helps to form a uniform solution, improve the solubility of the perovskite precursor solution, and is conducive to the preparation of a high-quality perovskite light absorbing layer.

[0070] In the embodiment of the present application, preferably, a large-area perovskite light-absorbing layer can be prepared by a slit coating method. The slit coating method has the characteristics of high efficiency and high precision, and has obvious advantages in industrial mass production when preparing a large-area perovskite light-absorbing layer. It can achieve precise control of the solution flow rate, coating speed, and coating thickness, so as to obtain a uniform film thickness on a large-area substrate, and is suitable for a variety of solvents and solution systems. The process parameters can be adjusted to adapt to different types of perovskite materials, including organic-inorganic hybrids and all-inorganic perovskites. The crystallization treatment method for the perovskite light-absorbing layer includes air knife blowing or vacuum drying (VCD). Air knife blowing is suitable for rapid drying and controlling grain growth, while vacuum drying is more conducive to crystallization integrity and film stability. Preferably, air knife blowing and vacuum drying (VCD) are often used in combination to optimize the film quality of the perovskite light-absorbing layer, thereby improving the efficiency and long-term stability of perovskite optoelectronic devices.

[0071] In some embodiments, the concentration of the phenolic antioxidant in the perovskite precursor solution is 100-1000 ppm (e.g., 100 ppm, 300 ppm, 500 ppm, 700 ppm, 900 ppm, 1000 ppm).

[0072] In the embodiment of the present application, by adding a phenolic antioxidant at a concentration of 100-1000 ppm to the perovskite precursor solution, the wettability of the perovskite precursor solution to the hole transport layer can be effectively improved, and the coating uniformity and film quality of the perovskite light absorbing layer can be improved.

[0073] In some embodiments, the method for preparing the perovskite light absorbing layer comprises the following steps: The perovskite precursor solution is coated on the hole transport layer and annealed to obtain a perovskite light absorbing layer; The annealing treatment is carried out in an inert atmosphere, the annealing temperature is 100-150°C (for example, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C), and the annealing time is 10-30min (for example, 10min, 15min, 20min, 25min, 30min).

[0074] In the embodiment of the present application, the annealing treatment can be performed by hot plate annealing or oven annealing; the annealing treatment is performed in an inert atmosphere (such as nitrogen) to prevent oxidation. Controlling the annealing process can improve the film quality of the perovskite light absorbing layer and help obtain a higher photoelectric conversion efficiency. More preferably, when the annealing temperature is 130°C, the film quality of the perovskite light absorbing layer can be further improved, which helps obtain a higher photoelectric conversion efficiency.

[0075] The following specific examples further illustrate the present application, but should not be construed as limiting the present application. Without departing from the spirit and substance of the present application, modifications or replacements made to the methods, steps or conditions of the present application are within the scope of the present application.

[0076] Example 1 An inverted perovskite solar cell, such as Figure 1 As shown, it includes: a substrate 1, a hole transport layer 2, a perovskite light absorption layer 3, a passivation layer 4, an electron transport layer 5, a buffer layer 6, and an electrode 7 which are stacked in sequence.

[0077] The specific preparation process of an inverted perovskite solar cell is as follows: Step S1a: providing a substrate 1 with a size of 30 cm×30 cm, wherein the substrate 1 is an indium tin oxide (ITO) transparent conductive glass; ultrasonically cleaning the substrate 1 with deionized water, isopropyl alcohol, and ethanol, respectively, with each cleaning time being 20 min, and drying with nitrogen after cleaning to obtain a first target substrate; Step S2a: dissolving the hole transport layer material Me-4PACz and a trace amount of 2,6-di-tert-butyl-p-cresol (BHT) in an ethanol solution and stirring evenly to prepare a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution is 0.8 mg / mL and the concentration of BHT is 20 ppm; then coating the hole transport layer precursor solution on the upper surface of the first target substrate by a slit coating method, performing a hot plate annealing treatment in a nitrogen atmosphere to remove the solvent, and preparing a hole transport layer 2; during the annealing treatment, the annealing temperature is 90° C., the annealing time is 5 min, and the thickness of the hole transport layer 2 is 1.5 nm; Step S3a: The perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powders are mixed to obtain a mixture, and 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) is added to the mixture to dissolve the mixture to obtain FA 0.9 Cs 0.1 PbI3 perovskite precursor solution; then in FA 0.9 Cs 0.1 A trace amount of BHT was added to the PbI3 perovskite precursor solution and mixed evenly. The BHT concentration was 200ppm. The FA with BHT added was coated by slit coating. 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, an annealing treatment is performed at a temperature of 130° C. and an annealing time of 20 min to form a perovskite light absorption layer 3 with a thickness of 600 nm; Step S4a: using a thermal evaporation method, depositing a passivation layer material 1,4-phenylenediamine hydroiodide (PDADI) on the upper surface of the perovskite light absorbing layer 3 at an evaporation rate of 0.2Å / s for 50s to form a passivation layer 4 with a thickness of 1nm; Step S5a: Using thermal evaporation method, C is deposited on the upper surface of the passivation layer 4 at an evaporation rate of 0.1 Å / s. 60 (fullerene), the evaporation time is 1500s, to form an electron transport layer 5, the thickness of the electron transport layer 5 is 15nm; Step S6a: using a thermal evaporation method, bathocuproin (BCP) is deposited on the upper surface of the electron transport layer 5 at an evaporation rate of 0.1 Å / s for 600 s to form a buffer layer 6. The thickness of the buffer layer 6 is 6 nm. Step S7a: using thermal evaporation method, copper (Cu) is deposited on the upper surface of the buffer layer 6 at an evaporation rate of 1Å / s for 1500s to form an electrode 7 with a thickness of 150nm.

[0078] Example 2 The inverted perovskite solar cell of Example 2 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 2 was as follows: dissolving the hole transport layer material Me-4PACz and a trace amount of 2,6-di-tert-butyl-p-cresol (BHT) in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.5 mg / mL, and the concentration of BHT was 20 ppm; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and hot plate annealing was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 80°C, the annealing time was 10 min, and the thickness of the hole transport layer 2 was 1.5 nm.

[0079] Example 3 The inverted perovskite solar cell of Example 3 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 3 was as follows: dissolving the hole transport layer material Me-4PACz and a trace amount of 2,6-di-tert-butyl-p-cresol (BHT) in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 2.0 mg / mL, and the concentration of BHT was 20 ppm; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and hot plate annealing was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 100° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm.

[0080] Example 4 The inverted perovskite solar cell of Example 4 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 4 was as follows: dissolving the hole transport layer material Me-4PACz and a trace amount of 2,6-di-tert-butyl-p-cresol (BHT) in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL, and the concentration of BHT was 10 ppm; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and hot plate annealing was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm.

[0081] Example 5 The inverted perovskite solar cell of Example 5 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 5 was as follows: dissolving the hole transport layer material Me-4PACz and a trace amount of 2,6-di-tert-butyl-p-cresol (BHT) in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL, and the concentration of BHT was 1000 ppm; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and hot plate annealing was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm.

[0082] Example 6 The inverted perovskite solar cell of Example 6 was prepared by referring to the preparation method of Example 1, except that step S3a of Example 6 was as follows: perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powders were mixed to obtain a mixture, and 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) was added to the mixture to dissolve the mixture to obtain FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; then in FA 0.9 Cs 0.1 A trace amount of BHT was added to the PbI3 perovskite precursor solution and mixed evenly. The BHT concentration was 100ppm. The FA with BHT added was coated by slit coating. 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0083] Example 7 The inverted perovskite solar cell of Example 7 was prepared by referring to the preparation method of Example 1, except that step S3a of Example 7 was as follows: perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powders were mixed to obtain a mixture, and 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) was added to the mixture to dissolve the mixture to obtain FAI. 0.9 Cs 0.1PbI3 perovskite precursor solution; then in FA 0.9 Cs 0.1 A trace amount of BHT was added to the PbI3 perovskite precursor solution and mixed evenly. The BHT concentration was 1000ppm. The FA with BHT added was coated by slit coating. 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0084] Example 8 The inverted perovskite solar cell of Example 8 was prepared by referring to the preparation method of Example 1, except that step S3a of Example 8 was as follows: perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powders were mixed to obtain a mixture, and 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) was added to the mixture to dissolve the mixture to obtain FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; then in FA 0.9 Cs 0.1 A trace amount of BHT was added to the PbI3 perovskite precursor solution and mixed evenly. The BHT concentration was 200ppm. The FA with BHT added was coated by slit coating. 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 100° C. for 30 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0085] Example 9 The inverted perovskite solar cell of Example 9 was prepared by referring to the preparation method of Example 1, except that step S3a of Example 9 was as follows: perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powders were mixed to obtain a mixture, and 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) was added to the mixture to dissolve the mixture to obtain FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; then in FA 0.9 Cs 0.1A trace amount of BHT was added to the PbI3 perovskite precursor solution and mixed evenly. The BHT concentration was 200ppm. The FA with BHT added was coated by slit coating. 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 150° C. for 10 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0086] Example 10 The inverted perovskite solar cell of Example 10 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 10 was as follows: dissolving the hole transport layer material Me-4PACz and a trace amount of 3-BHA in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL, and the concentration of 3-BHA was 20 ppm; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and hot plate annealing was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2, and during the annealing treatment, the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm; Step S3a of Example 10 is: mixing the perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powder to obtain a mixture, adding 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) to the mixture to dissolve the mixture, and obtaining FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; FA was coated by slit coating 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0087] Embodiment 11 The inverted perovskite solar cell of Example 11 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 11 was as follows: dissolving the hole transport layer materials Me-4PACz and 2-BHA in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL, and the concentration of 2-BHA was 20 ppm; then coating the hole transport layer precursor solution on the upper surface of the first target substrate by a slit coating method, performing a hot plate annealing treatment in a nitrogen atmosphere, removing the solvent, and preparing a hole transport layer 2, wherein the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm; Step S3a of Example 11 is: mixing the perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powder to obtain a mixture, adding 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) to the mixture to dissolve the mixture, and obtaining FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; FA was coated by slit coating 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0088] Example 12 The inverse-structure perovskite solar cell of Example 12 was prepared by referring to the preparation method of Example 1, except that step S2a of Example 12 was as follows: dissolving the hole transport layer materials Me-4PACz and tert-butylhydroquinone in an ethanol solution, stirring evenly, and preparing a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL, and the concentration of tert-butylhydroquinone was 20 ppm; then coating the hole transport layer precursor solution on the upper surface of the first target substrate by a slit coating method, performing a hot plate annealing treatment in a nitrogen atmosphere, removing the solvent, and preparing a hole transport layer 2, wherein the annealing temperature during the annealing treatment was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm; Step S3a of Example 12 is: mixing the perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powder to obtain a mixture, adding 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) to the mixture to dissolve the mixture, and obtaining FAI. 0.9 Cs 0.1 PbI3 perovskite precursor solution; FA was coated by slit coating 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0089] Comparative Example 1 The inverse-structure perovskite solar cell of Comparative Example 1 was prepared by referring to the preparation method of Example 1, except that (1) step S2a was as follows: Me-4PACz, a material of the hole transport layer, was dissolved in an ethanol solution and stirred evenly to prepare a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and a hot plate annealing treatment was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm; (2) Step S3a is: mixing the perovskite materials formamidinium iodide (FAI), lead iodide (PbI2), methylammonium chloride (MACl), lead chloride (PbCl2), and cesium iodide (CsI) powder to obtain a mixture, adding 25 mL of a mixed solution of N,N-dimethylformamide and N-methylpyrrolidone (DMF:NMP volume ratio of 6.5:1) to the mixture to dissolve the mixture, and obtaining FA 0.9 Cs 0.1 PbI3 perovskite precursor solution; FA was coated by slit coating 0.9 Cs 0.1 The PbI3 perovskite precursor solution is coated on the upper surface of the hole transport layer 2 to form a perovskite wet film; after vacuum drying, annealing is performed at a temperature of 130° C. for 20 minutes to form a perovskite light absorption layer 3 with a thickness of 600 nm.

[0090] Comparative Example 2 The inverted perovskite solar cell of Comparative Example 2 was prepared by referring to the preparation method of Example 1, except that step S2a of Comparative Example 2 was as follows: dissolving the material Me-4PACz of the hole transport layer in an ethanol solution and stirring evenly to prepare a hole transport layer precursor solution, wherein the concentration of Me-4PACz in the hole transport layer precursor solution was 0.8 mg / mL; then, the hole transport layer precursor solution was coated on the upper surface of the first target substrate by a slit coating method, and a hot plate annealing treatment was performed in a nitrogen atmosphere to remove the solvent to obtain a hole transport layer 2. During the annealing treatment, the annealing temperature was 90° C., the annealing time was 5 min, and the thickness of the hole transport layer 2 was 1.5 nm.

[0091] Comparative Example 3 The inverted perovskite solar cell of Comparative Example 3 was prepared by referring to the preparation method of Comparative Example 1, except that the size of the substrate 1 in Comparative Example 3 was 100 mm x 100 mm.

[0092] The following is a performance test of the inverted structure perovskite solar cells provided in Examples 1-12 of the present application and Comparative Examples 1-3, so as to obtain the open circuit voltage Voc, fill factor FF, short circuit current density Jsc, and photoelectric conversion efficiency PCE of the corresponding battery devices. The test results are shown in Table 1.

[0093] Table 1 Performance test results of inverse structure perovskite solar cells of Examples 1-12 and Comparative Examples 1-3

[0094] It can be seen from the test results of Examples 1-12 and Comparative Examples 1-3 that by doping the hole transport layer precursor solution with a phenolic antioxidant, under the joint action of the benzene ring, phenolic hydroxyl group and butyl group, the wettability of the hole transport layer to the substrate can be improved, the film formation of the hole transport layer can be optimized, the process stability of the hole transport layer can be improved, and this is helpful to obtain a higher photoelectric conversion efficiency; under the joint action of the benzene ring and the butyl group, the stability of the hole transport layer precursor solution in the air environment can be effectively improved, and in the process of large-area coating of the hole transport layer precursor solution, it is beneficial to prevent the hole transport layer precursor solution from uncontrollable deterioration, and can optimize the film formation of the hole transport layer, improve the process stability of the hole transport layer, and help obtain a higher photoelectric conversion efficiency.

[0095] It can be seen from Table 1 that compared with Example 2, in Example 2, after adding phenolic antioxidants to the perovskite precursor solution, the interface wettability of the hole transport layer and the perovskite light absorbing layer is improved, and the filling factor is increased from 78.16% to 80.34%. At the same time, due to the certain filtering ability of the perovskite light absorbing layer with the addition of phenolic antioxidants to the UVb band, the perovskite light absorbing layer has a good performance under the conditions of 15kWh / m 2After 72 hours of ultraviolet irradiation, the photoelectric conversion efficiency of the comparative example 1 decayed to below 50%, while the photoelectric conversion efficiency of the battery assembly of the comparative example 2 still maintained 73%.

[0096] Referring to the data of Example 1, it can be seen that when the phenolic antioxidant is added to the hole transport layer precursor solution and the perovskite light absorption layer precursor solution at the same time, the open circuit voltage, fill factor, short circuit current density and photoelectric conversion efficiency of Example 1 are significantly improved, and the average efficiency of 10 cells reaches 20.88%. In addition, the battery assembly of Example 1 is subjected to 15kWh / m 2 After 72 hours of ultraviolet irradiation, the photoelectric conversion efficiency remained at 76%.

[0097] In summary, phenolic antioxidants as additives in hole transport layer precursor solutions and perovskite light absorbing precursor solutions can be used as a universal technology in the industrial preparation of large-area perovskite solar cells. On the basis of not affecting the main components and the structure of key active substances, the long-term environmental stability and process repeatability of the precursor solution can be improved, thereby achieving an increase in yield. In addition, phenolic antioxidants have their own unique roles in the hole transport layer and the perovskite light absorbing layer. When phenolic antioxidants are used as additives in the SAM layer (taking Me-4PACz with poor wettability as an example), on the one hand, they can improve the wettability, and on the other hand, they can also play a role in filtering UVb band ultraviolet light, reducing its damage to the perovskite light absorbing layer; when phenolic antioxidants are used as additives in the perovskite light absorbing layer, they can effectively improve the photostability of the perovskite film, which is specifically manifested in its resistance to ultraviolet light.

[0098] Referring to the data of Examples 1-3, it can be seen that optimizing the concentration of the hole transport layer material in the hole transport layer precursor solution can further reduce interface losses, improve the battery fill factor, and help obtain higher photoelectric conversion efficiency.

[0099] Referring to the battery performance test results of Examples 1, 4-5, and 10-12, it can be seen that optimizing the amount of phenolic antioxidant added in the hole transport layer can further reduce the interface defects between the hole transport layer and the perovskite light absorbing layer, improve the battery filling factor, and help obtain higher photoelectric conversion efficiency.

[0100] Referring to the battery performance test results of Examples 1 and 6-7, it can be seen that optimizing the amount of phenolic antioxidant added in the perovskite light absorbing layer can further stabilize the perovskite precursor solution, improve the film quality of the perovskite light absorbing layer, and help obtain higher photoelectric conversion efficiency.

[0101] Referring to the battery performance test results of Examples 1 and 8-9, it can be seen that optimizing the annealing temperature and time of the perovskite light absorbing layer can further improve the film quality of the perovskite light absorbing layer, which helps to obtain a higher photoelectric conversion efficiency.

[0102] With reference to the battery performance test results of Examples 1-12, it can be seen that the technical solution of the present application is conducive to the preparation of large-area perovskite solar cells.

[0103] The embodiment of the present application can provide a photovoltaic cell assembly (not shown), and the embodiment of the present application also provides a photovoltaic cell assembly, including the above-mentioned inverse structure perovskite solar cell. The photovoltaic cell assembly also has the advantages of the above-mentioned inverse structure perovskite solar cell.

[0104] It should be noted that the terms "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.

[0105] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0106] It should also be noted that "one embodiment", "another embodiment", "embodiment", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Further, when describing a specific feature, structure or characteristic in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.

[0107] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0108] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A hole transport layer precursor solution, characterized in that: include: Hole transport layer materials, phenolic antioxidants, organic solvents; The structure of the phenolic antioxidant includes a benzene ring, a phenolic hydroxyl group and a butyl group.

2. The hole transport layer precursor solution according to claim 1, characterized in that: The phenolic antioxidant has 1-2 phenolic hydroxyl groups on its benzene ring; The benzene ring of the phenolic antioxidant is provided with 1-2 butyl groups.

3. The hole transport layer precursor solution according to claim 2, characterized in that: When two phenolic hydroxyl groups are arranged on the benzene ring of the phenolic antioxidant, the position relationship between the phenolic hydroxyl groups is para; And / or, when two butyl groups are arranged on the benzene ring of the phenolic antioxidant, the positional relationship between the butyl groups is meta.

4. The hole transport layer precursor solution according to claim 1, characterized in that: The phenolic antioxidant includes one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole and tert-butylhydroquinone.

5. The hole transport layer precursor solution according to claim 1, characterized in that: The organic solvent includes one or more of ethanol, 2-methoxyethanol, N,N-dimethylformamide, acetonitrile, isopropanol, and chlorobenzene.

6. The hole transport layer precursor solution according to claim 1, characterized in that: The concentration of the phenolic antioxidant is 10 to 1000 ppm; And / or, the concentration of the hole transport layer material is 0.5-2.0 mg / ml.

7. A method for preparing a hole transport layer, characterized in that: The steps include: coating a hole transport layer precursor solution on a substrate and performing an annealing treatment to obtain a hole transport layer; The hole transport layer precursor solution comprises a hole transport layer material, a phenolic antioxidant, and an organic solvent; the structure of the phenolic antioxidant comprises a benzene ring, a phenolic hydroxyl group, and a butyl group.

8. The method for preparing a hole transport layer according to claim 7, characterized in that: The annealing treatment is carried out in an inert atmosphere, the annealing temperature is 80-100° C., and the annealing time is 5-10 minutes.

9. A hole transport layer, characterized in that: The hole transport layer is formed by the hole transport layer precursor solution according to any one of claims 1 to 6; Or, the hole transport layer is prepared by the method according to any one of claims 7 to 8.

10. A perovskite solar cell, characterized in that: include: A substrate, a hole transport layer, a perovskite light absorption layer, and an electron transport layer are stacked in sequence; The hole transport layer is formed by the hole transport layer precursor solution according to any one of claims 1 to 6; Or, the hole transport layer is prepared by the method according to any one of claims 7 to 8.

11. The perovskite solar cell according to claim 10, characterized in that: The perovskite light absorbing layer is formed from a perovskite precursor solution; The perovskite precursor solution comprises: a perovskite material, a phenolic antioxidant, and a solvent.

12. The perovskite solar cell according to claim 11, characterized in that: In the perovskite precursor solution, the concentration of the phenolic antioxidant is 100-1000 ppm.

13. A photovoltaic cell assembly, characterized in that: A perovskite solar cell comprising the following claim 10 to 12.

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