Composite perovskite thin film and preparation method thereof, perovskite solar cell and photovoltaic module

Abstract

The invention relates to the technical field of photovoltaics, particularly provides a composite perovskite thin film and a preparation method thereof, a perovskite solar cell and a photovoltaic module, and aims to solve the problems that an existing perovskite cell is complex in process and long in preparation time. Therefore, the preparation method of the composite perovskite thin film comprises the following steps: providing a first mixed solution composed of a hole transport material and an inorganic salt solution; providing a second mixed solution composed of an electron transport material and an organic salt solution; coating a first mixed solution on a substrate, and carrying out first annealing treatment to obtain a transition film on the substrate; and coating the inorganic salt skeleton layer of the transition thin film with a second mixed solution, and carrying out second annealing treatment to obtain the composite perovskite thin film on the substrate. According to the preparation method of the composite perovskite thin film, the three functional layers including the hole transport layer, the perovskite layer and the electron transport layer can be prepared at the same time through a two-step solution method, the preparation steps of a perovskite cell are effectively simplified, time is saved, and the preparation efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and specifically provides a composite perovskite film and a preparation method thereof, a perovskite solar cell and a photovoltaic module. Background Art

[0002] As a clean and renewable energy source, solar energy has garnered widespread attention from both academia and industry. Currently, perovskite solar cells (PSCs) are attracting significant attention among third-generation solar cells due to their excellent optoelectronic performance, high photoelectric conversion efficiency, low-cost solution-based preparation, and simple process. Currently, the structures of both formal and inverted perovskite solar cells primarily consist of an electron transport layer (ETL), a perovskite light-absorbing layer, a hole transport layer (HTL), and a metal electrode. When preparing inverted perovskite solar cells, the general preparation sequence is: NiOx layer, SAMs layer, perovskite layer, electron transport layer, and back electrode layer. The perovskite film is typically prepared using a one-step or two-step process. In the one-step process, the perovskite precursor is first dissolved in a solvent, then a perovskite liquid film is obtained by spin coating, doctor blade coating, or slit coating. The solvent is then rapidly removed using an antisolvent method or VCD, and the perovskite film is annealed. In the two-step method, the first step is to dissolve lead iodide in a solvent, and then obtain a lead iodide liquid film by spin coating, blade coating or slit coating, and then obtain a lead iodide thin film after annealing; the second step is to dissolve FAI in ethanol or isopropanol, and then apply the FAI solution onto the lead iodide film layer by spin coating, blade coating or slit coating, and then obtain a perovskite thin film after annealing.

[0003] However, although the various preparation methods mentioned above have been widely used, many problems still exist, especially the fact that too many film layer structures need to be prepared in sequence, which increases the process steps and preparation time.

[0004] Accordingly, this field requires a new technical solution to solve the above technical problems. Summary of the Invention

[0005] The present application aims to solve the above-mentioned technical problems, namely, to solve the problems of complex processes and long preparation time required for existing perovskite cells.

[0006] In a first aspect, the present application provides a method for preparing a composite perovskite film, wherein the composite perovskite film includes a hole transport layer, a perovskite layer and an electron transport layer distributed in sequence, and the preparation method includes the following steps: providing a first mixed solution composed of a hole transport material and an inorganic salt solution; providing a second mixed solution composed of an electron transport material and an organic salt solution; coating the first mixed solution on a substrate, performing a first annealing treatment, and obtaining a transition film on the substrate; wherein the transition film includes a hole transport layer and an inorganic salt skeleton layer, and the hole transport layer is located between the substrate and the inorganic salt skeleton layer; coating the second mixed solution on the inorganic salt skeleton layer of the transition film, performing a second annealing treatment, so that the inorganic salt skeleton layer reacts with the organic salt solution to generate a perovskite layer, and at the same time obtaining an electron transport layer on the side of the perovskite layer away from the hole transport layer, and obtaining a composite perovskite film on the substrate.

[0007] In the preferred technical solution of the above-mentioned method for preparing the composite perovskite film, the inorganic salt solution includes a lead iodide solution, wherein the solvent in the lead iodide solution is one or more solvents such as dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, γ-butyrolactone, etc.; and / or the concentration of the hole transport material in the first mixed solution is 0.1 to 6 mg / mL; preferably, the concentration of the hole transport material in the first mixed solution is 0.3 to 1.5 mg / mL; and / or, the hole transport material includes a SAM material; and / or, the organic salt solution is a FAI solution, wherein the solvent in the FAI solution is one or more solvents such as ethanol, isopropanol, methanol, dimethoxyethanol, etc.; and / or, the concentration of the electron transport material in the second mixed solution is 0.1 to 10 mg / mL; preferably, the concentration of the electron transport material in the second mixed solution is 2 to 6 mg / mL; and / or, the electron transport material is insoluble or slightly soluble in the organic salt solution.

[0008] In the preferred technical solution of the above-mentioned method for preparing the composite perovskite thin film, the concentration of the lead iodide solution is 0.5-1.5 mol / L; and / or the inorganic salt solution is doped with a second inorganic salt, and the second inorganic salt includes one or more of CsI, CsBr, CsCl, PbBr2, and PbCl2; and / or the inorganic salt solution is further doped with a first passivation material, and the first passivation material includes a potassium halide salt and / or a rubidium halide salt; and / or the concentration of the FAI solution is 0.2-1.5 mol / L; and / or the solvent in the FAI solution is ethanol; and / or the organic salt solution is doped with a second organic salt, and the second organic salt includes one or more of FABr, FACl, MAI, MABr, and MACl; and / or the organic salt solution is doped with a second passivation material, and the second passivation material is PEAI and / or PMAI.

[0009] In the preferred technical solution of the above-mentioned method for preparing the composite perovskite thin film, the molar addition amount of the second inorganic salt is 0.05% to 5% of the lead iodide, preferably the molar addition amount of the second inorganic salt is 5% of the lead iodide; and / or the molar addition amount of the first passivation material is 0.05% to 5% of the lead iodide; and / or the concentration of the second organic salt in the organic salt solution is 0.05 to 1 mol / L; and / or the molar addition amount of the second passivation material is 0.05% to 5% of the FAI.

[0010] In the preferred technical solution of the above-mentioned method for preparing the composite perovskite film, the SAM material includes one or more of MeO-2PACz, 2PACz, Me-2PACz, MeO-4PACz, Me-4PACz, and 4PACz; and / or the electron transport material includes C 60 , PCBM, PTAA, SnO2 or more.

[0011] In the preferred technical solution of the above-mentioned method for preparing the composite perovskite thin film, the first annealing temperature of the first annealing treatment is 50-100°C, and the first annealing time is 1-10 minutes; and / or the second annealing temperature of the second annealing treatment is 100-160°C, and the second annealing time is 5-30 minutes.

[0012] In a second aspect, the present application provides a composite perovskite film, which includes a hole transport layer, a perovskite layer and an electron transport layer distributed in sequence, and the composite perovskite film is prepared by the above-mentioned composite perovskite film preparation method.

[0013] In a third aspect, the present application provides a perovskite solar cell, which comprises, from bottom to top, a layered substrate, a composite perovskite film, a buffer layer, and a back electrode, wherein the composite perovskite film comprises, from bottom to top, a hole transport layer, a perovskite layer, and an electron transport layer, wherein the composite perovskite film is the above-mentioned composite perovskite film or is prepared by the above-mentioned composite perovskite film preparation method.

[0014] In the preferred technical solution of the above-mentioned perovskite solar cell, the substrate includes one of ITO transparent conductive glass, FTO transparent conductive glass, IWO transparent conductive glass, and AZO transparent conductive glass; and / or the back electrode includes a metal electrode or a metal oxide transparent electrode.

[0015] In a fourth aspect, the present application provides a photovoltaic module, which includes the above-mentioned perovskite solar cell.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0017] The preparation method of the composite perovskite film of the present application is to mix the hole transport material with an inorganic salt solution and the electron transport material with an organic salt solution, and then simultaneously prepare the hole transport layer and the electron transport layer in the process of preparing the perovskite layer by a two-step solution method. Therefore, the three functional layers of the hole transport layer, the perovskite layer and the electron transport layer can be simultaneously prepared by the two-step solution method, which effectively simplifies the preparation steps of the perovskite battery, saves time and improves the preparation efficiency.

[0018] In addition, the hole transport layer, perovskite layer and electron transport layer of the composite perovskite film prepared by this preparation method are closely connected to each other, which can reduce the defects of the upper and lower interfaces that may appear when the perovskite layer is prepared separately, reduce the non-radiative recombination of carriers at the interface of the perovskite film, and improve the photoelectric performance and stability of the perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The preferred embodiments of the present application are described below with reference to the accompanying drawings, in which:

[0020] Figure 1 is a flow chart of the method for preparing the composite perovskite film of the present application;

[0021] Figure 2 Schematic diagram of the structure of the composite perovskite film of the present application;

[0022] Figure 3 It is a schematic structural diagram of the perovskite battery of this application.

[0023] List of reference numerals:

[0024] 1. Base;

[0025] 2. Composite perovskite film; 21. Hole transport layer; 22. Perovskite layer; 23. Electron transport layer;

[0026] 3. Buffer layer;

[0027] 4. Back electrode. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application.

[0029] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0030] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0031] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0032] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0033] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0034] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features being referred to. For example, without departing from the scope of the embodiments of this application, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0035] The experimental methods in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0036] It should be noted that, in the description of this application, terms such as "upper" and "lower" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for ease of description and does not indicate or imply that the device or element described must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, it should not be understood as limiting this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance.

[0037] Furthermore, it should be noted that, in the description of this application, unless otherwise specified or limited, the term "connection" should be understood in a broad sense. For example, it can refer to a fixed connection, a detachable connection, or an integral connection; it can refer to a direct connection or an indirect connection through other components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0038] Based on the problems pointed out in the background technology, the existing perovskite battery process is complex and the preparation time is long.

[0039] The preparation method of the composite perovskite film of the present application is to mix the hole transport material with an inorganic salt solution and the electron transport material with an organic salt solution, and then simultaneously prepare the hole transport layer and the electron transport layer in the process of preparing the perovskite layer by a two-step solution method. Therefore, the three functional layers of the hole transport layer, the perovskite layer and the electron transport layer can be simultaneously prepared by the two-step solution method, which effectively simplifies the preparation steps of the perovskite battery, saves time and improves the preparation efficiency.

[0040] In the first place, see Figure 1 The present application provides a method for preparing a perovskite thin film, the preparation method comprising the following steps:

[0041] S1: providing a first mixed solution consisting of a hole transport material and an inorganic salt solution.

[0042] S2: providing a second mixed solution consisting of an electron transport material and an organic salt solution.

[0043] S3: coating the first mixed liquid on the substrate and performing a first annealing treatment to obtain a transition film on the substrate; wherein the transition film includes a hole transport layer and an inorganic salt skeleton layer, and the hole transport layer is located between the substrate and the inorganic salt skeleton layer.

[0044] S4: coating a second mixed liquid on the inorganic salt skeleton layer of the transition film, and performing a second annealing treatment to allow the inorganic salt skeleton layer to react with the organic salt solution to form a perovskite layer, and at the same time obtaining an electron transport layer on the side of the perovskite layer away from the hole transport layer, thereby obtaining a composite perovskite film on the substrate.

[0045] The preparation method of the composite perovskite film of the present application is to mix the hole transport material with an inorganic salt solution and the electron transport material with an organic salt solution, and then prepare the hole transport layer and the electron transport layer at the same time during the two-step solution method for preparing the perovskite layer. Thus, the three functional layers of the hole transport layer, the perovskite layer and the electron transport layer can be prepared simultaneously by the two-step solution method, effectively simplifying the preparation steps of the perovskite battery, saving time and improving the preparation efficiency. In addition, the hole transport layer, the perovskite layer and the electron transport layer of the composite perovskite film prepared by this preparation method are closely connected to each other, which can reduce the defects of the upper and lower interfaces that may occur when the perovskite layer is prepared separately, reduce the non-radiative recombination of carriers at the interface of the perovskite film, and improve the photoelectric performance and stability of the perovskite solar cell.

[0046] Preferably, the inorganic salt solution includes a lead iodide solution, wherein the solvent in the lead iodide solution is one or more solvents selected from dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, γ-butyrolactone, and the like.

[0047] More preferably, the concentration of lead iodide in the lead iodide solution is 0.5 to 1.5 mol / L.

[0048] Specifically, the concentration of lead iodide can be 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, and a value between any two of the above values.

[0049] Most preferably, the concentration of the lead iodide solution is 1 mol / L.

[0050] It should be noted that setting the concentration of lead iodide to 0.5-1.5 mol / L is a concentration range commonly used in this field. In practical applications, those skilled in the art can also adjust the concentration of lead iodide to other concentrations outside this range according to actual needs. The adjustment and change of the lead iodide concentration does not deviate from the basic principles of this application and should be limited to the scope of protection of this application.

[0051] Preferably, the concentration of the hole transport material in the first mixed solution is 0.1-6 mg / mL.

[0052] Specifically, the concentration of the hole transport material can be 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, and values ​​between any two of the above values.

[0053] In some preferred embodiments, the concentration of the hole transport material in the first mixed solution is 0.3-1.5 mg / mL.

[0054] Specifically, the concentration of the hole transport material can be 0.3 mg / mL, 0.5 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, 1 mg / mL, 1.2 mg / mL, 1.5 mg / mL, and values ​​between any two of the above values.

[0055] Most preferably, the concentration of the hole transport material in the first mixed solution is 1 mg / mL.

[0056] If the concentration of the hole transport material is too low, continuous coverage cannot be formed, which affects the extraction of holes. If the concentration of the hole transport material is too high, the hole transport material will be excessively accumulated and the thickness will be relatively high, which will affect the transport of holes. Therefore, if the concentration of the hole transport material is too high or too low, the efficiency and stability of the device will be affected. Controlling the concentration of the hole transport material in the first mixed liquid to 0.1-6 mg / mL, and preferably controlling the concentration of the hole transport material in the first mixed liquid to 0.3-1.5 m / mL, can improve the performance of the solar cell.

[0057] Preferably, the hole transport material comprises a SAM material.

[0058] Preferably, the SAM material includes one or more of MeO-2PACz, 2PACz, Me-2PACz, MeO-4PACz, Me-4PACz, and 4PACz.

[0059] In some preferred embodiments, the inorganic salt solution is doped with a second inorganic salt, and the second inorganic salt includes one or more of CsI, CsBr, CsCl, PbBr2, and PbCl2.

[0060] Preferably, the molar addition amount of the second inorganic salt in the inorganic salt solution is 0.05% to 5% of the lead iodide.

[0061] Most preferably, the molar addition amount of the second inorganic salt in the inorganic salt solution is 5% of the lead iodide.

[0062] The crystal phase structure of the perovskite layer can be changed by doping a second inorganic salt, thereby obtaining a perovskite layer with better performance. The structure and doping concentration of the second inorganic salt can be adjusted according to the target perovskite material.

[0063] In some preferred embodiments, the inorganic salt solution is further doped with a first passivation material, the first passivation material includes potassium halide salts and / or rubidium halide salts, the potassium halide salts include potassium iodide, potassium bromide, potassium chloride, and the rubidium halide salts include rubidium iodide, rubidium bromide, and rubidium chloride.

[0064] Preferably, the molar addition amount of the first passivation material in the inorganic salt solution is 0.05% to 5% of the lead iodide.

[0065] Most preferably, the molar addition amount of the first passivation material in the inorganic salt solution is 2% of the lead iodide.

[0066] Adding a small amount of the first passivation material to the inorganic salt solution helps to bulk passivate the perovskite layer, compensate for defects in the perovskite crystal phase, increase the open circuit voltage and fill factor of the solar cell, and thus improve the performance of the solar cell.

[0067] Preferably, the organic salt solution is an FAI solution, wherein the solvent in the FAI solution is one or more solvents such as ethanol, isopropanol, methanol, dimethoxyethanol, etc. Preferably, the solvent in the FAI solution is ethanol.

[0068] Preferably, the concentration of FAI in the FAI solution is 0.2 to 1.5 mol / L.

[0069] Specifically, the concentration of FAI in the FAI solution is 0.2 mol / L, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.3 mol / L, 1.5 mol / L, and a value between any two of the above values.

[0070] It should be noted that setting the FAI concentration to 0.2-1.5 mol / L is a concentration range commonly used in this field. In practical applications, those skilled in the art can also adjust the FAI concentration to other concentrations outside this range according to actual needs. The adjustment and change of the FAI concentration does not deviate from the basic principles of this application and should be limited to the scope of protection of this application.

[0071] Preferably, the concentration of the electron transport material in the second mixed solution is 0.1-10 mg / mL.

[0072] In some preferred embodiments, the concentration of the electron transport material in the second mixed solution is 2-6 mg / mL.

[0073] Specifically, the concentration of the electron transport material in the second mixed solution can be 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 3 mg / mL, 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL and values ​​between any two of the above values.

[0074] If the concentration of the electron transport material is too low, continuous coverage cannot be formed, which affects the extraction of electrons. If the concentration of the electron transport material is too high, the electron transport material is excessively accumulated and the thickness is relatively high, which affects the transmission of electrons. Therefore, if the concentration of the electron transport material is too high or too low, the efficiency and stability of the device will be affected. Controlling the concentration of the electron transport material in the second mixed liquid to 0.1 to 10 mg / mL, and preferably making the concentration of the electron transport material in the second mixed liquid to 2 to 6 mg / mL, can improve the performance of the solar cell.

[0075] Preferably, the electron transport material is insoluble or slightly soluble in the organic salt solution.

[0076] Preferably, the electron transport material comprises C 60 , PCBM, PTAA, SnO2 or more.

[0077] In some preferred embodiments, the organic salt solution is doped with a second organic salt, and the second organic salt includes one or more of FABr, FACl, MAI, MABr, and MACl.

[0078] Preferably, the concentration of the second organic salt in the organic salt solution is 0.05 to 1 mol / L.

[0079] Specifically, the concentration of the second organic salt in the organic salt solution can be 0.05mol / L, 0.1mol / L, 0.2mol / L, 0.3mol / L, 0.4mol / L, 0.5mol / L, 0.6mol / L, 0.7mol / L, 0.8mol / L, 0.9mol / L, 1mol / L and values ​​between any two of the above values.

[0080] The crystal phase structure of the perovskite layer can be changed by doping a second organic salt, thereby obtaining a perovskite layer with better performance. The structure and doping concentration of the second organic salt can be adjusted according to the target perovskite material.

[0081] In some preferred embodiments, the organic salt solution is doped with a second passivation material, and the second passivation material is PEAI and / or PMAI.

[0082] Preferably, the molar addition amount of the second passivation material in the organic salt solution is 0.05% to 5% of FAI.

[0083] Most preferably, the molar addition amount of the second passivation material in the organic salt solution is 5% of the FAI.

[0084] Adding a small amount of second passivation material to the organic salt solution helps to bulk passivate the perovskite layer, compensate for defects in the perovskite crystal phase, increase the open circuit voltage and fill factor of the solar cell, and thus improve the performance of the solar cell.

[0085] It should be noted that this application does not impose any restrictions on the specific execution steps of the first annealing treatment and the second annealing treatment. In actual applications, those skilled in the art can set the specific execution steps of the first annealing treatment and the second annealing treatment according to actual needs. For example, the first annealing treatment and the second annealing treatment can be set as a one-step annealing, or the first annealing treatment can be set as a single annealing and the second annealing treatment can be set as a two-step annealing, etc. Any adjustments and changes to the specific execution steps of the first annealing treatment and the second annealing treatment do not deviate from the basic principles of this application and should be limited to the scope of protection of this application.

[0086] In some embodiments, the first annealing temperature of the first annealing treatment is 50-100° C., and the first annealing time is 1-10 minutes.

[0087] In some embodiments, the second annealing temperature of the second annealing treatment is 100-160° C., and the second annealing time is 5-30 minutes.

[0088] In a second aspect, the present application provides a composite perovskite film, which is prepared by the composite perovskite film preparation method provided by the first aspect.

[0089] Specifically, see Figure 2 The composite perovskite film 2 includes a hole transport layer 21, a perovskite layer 22 and an electron transport layer 23 which are distributed in sequence.

[0090] The composite perovskite film 2 simultaneously comprises a hole transport layer 21, a perovskite layer 22 and an electron transport layer 23 and is produced by a two-step method. When applied to perovskite solar cells, it can effectively reduce process difficulty, save preparation time, simplify the preparation process and reduce costs.

[0091] In a third aspect, the present application provides a perovskite solar cell, which includes the perovskite thin film provided in the second aspect.

[0092] Specifically, see Figure 3 The perovskite cell includes a layered substrate 1, a perovskite film 2, a buffer layer 3 and a back electrode 4 from bottom to top. The composite perovskite film 2 includes a hole transport layer 21, a perovskite layer 22 and an electron transport layer 23 distributed from bottom to top.

[0093] Preferably, the substrate 1 includes any one of ITO transparent conductive glass, FTO transparent conductive glass, IWO transparent conductive glass, and AZO transparent conductive glass.

[0094] Preferably, the back electrode 4 includes a metal electrode (eg, an Ag electrode, an Au electrode, or a Cu electrode) or a metal oxide transparent electrode (eg, ITO, IZO, AZO, or IWO).

[0095] In a fourth aspect, the present application provides a photovoltaic module, which includes the perovskite solar cell provided in the third aspect.

[0096] The perovskite film and perovskite solar cell of the present application are described in detail below through several specific embodiments.

[0097] Example 1

[0098] The perovskite solar cell of this embodiment is prepared by the following steps:

[0099] S1: Provide a substrate, clean the ITO transparent conductive glass, and blow dry it with nitrogen.

[0100] S2: Preparing a composite perovskite film on a substrate, specifically including steps S21, S22, S23 and S24.

[0101] S21: Providing a first mixed solution consisting of a hole transport material and an inorganic salt solution, mixing PbI2 and CsI powders at a molar ratio of 100:5, adding a solvent (DMF:NMP = 5:1) to dissolve the mixture to obtain an inorganic salt solution, wherein the concentration of lead iodide in the inorganic salt solution is 1 mol / L and the concentration of cesium iodide is 0.05 mol / L. Dissolving the hole transport material Me-4PACz in the inorganic salt solution to a concentration of 1 mg / mL of Me-4PACz to obtain a first mixed solution.

[0102] S22: Providing a second mixed solution consisting of an electron transport material and an organic salt solution. FAI, MABr, and MACl powders are mixed in a molar ratio of 10:1:1, and ethanol is added to dissolve them to obtain an organic salt solution. The organic salt solution has a FAI concentration of 0.6 mol / L, a MABr concentration of 0.06 mol / L, and a MACl concentration of 0.06 mol / L. The electron transport material PCBM is added to the organic salt solution at a concentration of 4 mg / mL to obtain a second mixed solution.

[0103] S23: Spin-coating the first mixed liquid on the substrate with the spin-coating parameters of acceleration 1500 rpm / s, spin-coating speed 1500 rpm, and spin-coating time 15 s, and performing a first annealing treatment with an annealing temperature of 75°C and an annealing time of 1 min to obtain a 400 nm transition film on the substrate, wherein the transition film includes a hole transport layer and an inorganic salt skeleton layer, and the hole transport layer is located between the substrate and the inorganic salt skeleton layer. Specifically, during the annealing process, the hole transport material preferentially combines with the ITO transparent conductive glass, and the solidification and crystallization of lead iodide causes the hole transport material to be squeezed out of the lead iodide, thereby being distributed between the inorganic salt skeleton layer and the ITO transparent conductive glass to form a hole transport layer.

[0104] S24: Spin-coating a second mixed solution on the inorganic salt skeleton layer of the transition film, with the spin-coating parameters being an acceleration of 1500 rpm / s, a spin-coating speed of 1700 rpm, and a spin-coating time of 30 seconds. A second annealing treatment is performed, with an annealing temperature of 150°C and an annealing time of 20 minutes, so that the inorganic salt skeleton layer reacts with the organic salt solution to form a perovskite layer. At the same time, an electron transport layer is obtained on the side of the perovskite layer away from the hole transport layer, thereby obtaining a 650nm composite perovskite film on the substrate. Since the electron transport material PCBM is insoluble in ethanol and does not react with lead iodide, when the second mixed solution is spin-coated, the electron transport material is enriched above the inorganic salt skeleton layer. When FAI reacts with the inorganic salt skeleton layer to form a perovskite crystal phase, the electron transport material PCBM is squeezed out of the perovskite crystal phase, thereby forming an electron transport layer on the upper interface of the formed perovskite layer.

[0105] S3: A 6 nm BCP layer and a 150 nm back electrode (Au electrode) are sequentially deposited on the electron transport layer of the composite perovskite film by vacuum evaporation.

[0106] The preparation methods of the perovskite solar cells of Examples 2 to 10 are the same as those of Example 1. The difference from Example 1 is that the components and / or amounts of the hole transport material and / or electron transport layer are different. The compositions of the hole transport material and the electron transport material in Examples 2 to 10 are shown in Table 1.

[0107] Table 1 Composition of hole transport materials and electron transport materials of Examples 1 to 10

[0108] Example 11

[0109] The preparation method of the perovskite solar cell of this embodiment is the same as that of Example 1. The difference from Example 1 is that the inorganic salt solution of this embodiment is doped with a first passivation material. Specifically, the first passivation material is potassium iodide, and the molar addition amount of potassium iodide is 2% of lead iodide, that is, the concentration of potassium iodide in the inorganic salt solution is 0.02 mol / L.

[0110] Example 12

[0111] The preparation method of the perovskite solar cell in this embodiment is the same as that in Example 1. The difference from Example 1 is that the organic salt solution in this embodiment is doped with a second passivation material. Specifically, the second passivation material is PMAI, and the molar addition amount of PMAI is 5% of FAI, that is, the concentration of PMAI in the organic salt solution is 0.03 mol / L.

[0112] Example 13

[0113] The preparation method of the perovskite solar cell of this embodiment is the same as that of Example 1. The difference from Example 1 is that the inorganic salt solution of this embodiment is doped with a first passivation material, and the organic salt solution is doped with a second passivation material.

[0114] Specifically, the first passivation material is potassium iodide, and the molar addition amount of potassium iodide is 2% of lead iodide, that is, the concentration of potassium iodide in the inorganic salt solution is 0.02 mol / L; the second passivation material is PMAI, and the molar addition amount of PMAI is 5% of FAI, that is, the concentration of PMAI in the organic salt solution is 0.03 mol / L.

[0115] Example 14

[0116] The perovskite solar cell of this embodiment is prepared by the following steps:

[0117] S1: Provide a substrate, clean the FTO transparent conductive glass, and blow dry it with nitrogen. Use a 1064nm wavelength laser to scribe the PI, and use magnetron sputtering to deposit a 25nm NiOx layer.

[0118] S2: Preparing a composite perovskite film on a substrate, specifically including steps S21, S22, S23 and S24.

[0119] S21: Providing a first mixed solution consisting of a hole transport material and an inorganic salt solution, mixing PbI2 and CsI powders at a molar ratio of 100:5, adding a solvent (DMF:NMP = 5:1) to dissolve the mixture to obtain an inorganic salt solution, wherein the concentration of lead iodide in the inorganic salt solution is 1 mol / L and the concentration of cesium iodide is 0.05 mol / L. Dissolving the hole transport material Me-4PACz in the inorganic salt solution to a concentration of 1 mg / mL of Me-4PACz to obtain a first mixed solution.

[0120] S22: Provide a second mixed solution consisting of an electron transport material and an organic salt solution, mix FAI, MABr, and MACl powders in a molar ratio of 10:1:1, add ethanol to dissolve, and obtain an organic salt solution, wherein the concentration of FAI in the organic salt solution is 0.6 mol / L, the concentration of MABr is 0.06 mol / L, and the concentration of MACl is 0.06 mol / L. 60 Added to the organic salt solution, where C 60 The concentration of the mixture was 1 mg / mL to obtain a second mixed solution.

[0121] S23: Slit coating the first mixed liquid on the NiOx layer of the substrate, with coating parameters of coating speed 30 mm / s and liquid output 350 μL, and performing a first annealing treatment at 75°C and 1 minute, to obtain a 400 nm transition film on the substrate, wherein the transition film includes a hole transport layer and an inorganic salt skeleton layer, and the hole transport layer is located between the substrate and the inorganic salt skeleton layer. Specifically, during the annealing process, the hole transport material preferentially combines with NiOx, and the solidification and crystallization of lead iodide causes the hole transport material to be squeezed out of the lead iodide, thereby being distributed between the inorganic salt skeleton layer and the NiOx layer to form a hole transport layer.

[0122] S24: Slit coating the second mixed solution on the inorganic salt skeleton layer of the transition film, with coating parameters of coating speed 20 mm / s, liquid output 580 μL, and performing a second annealing treatment, with annealing temperature of 150°C and annealing time of 20 min, so that the inorganic salt skeleton layer reacts with the organic salt solution to form a perovskite layer, and at the same time, an electron transport layer is obtained on the side of the perovskite layer away from the hole transport layer, and a 650 nm composite perovskite film is obtained on the substrate. 60 It is insoluble in ethanol and does not react with lead iodide. When the second mixed solution is spin-coated, the electron transport material is enriched above the inorganic salt skeleton layer. When FAI reacts with the inorganic salt skeleton layer to form a perovskite crystal phase, the electron transport material C 60 squeezed out from the perovskite crystal phase, thereby forming an electron transport layer on the upper interface of the formed perovskite layer.

[0123] S3: A 20nm SnO2 layer was prepared on the electron transport layer of the composite perovskite film by ALD, and then P2 line was performed using a 532nm wavelength laser.

[0124] S4: Prepare an ITO / Cu / ITO composite back electrode on the SnO2 layer using PVD, with thicknesses of 30nm / 100nm / 50nm respectively.

[0125] S5: Use a 532nm wavelength laser to scribe P3, use a 1064nm laser to clean the edges, and connect the lead segments.

[0126] Comparative Example 1

[0127] The perovskite solar cell of this comparative example was prepared by the following steps:

[0128] S1: Provide a substrate, clean the ITO transparent conductive glass, and blow dry it with nitrogen.

[0129] S2: Prepare a hole transport layer on the substrate, dissolve the hole transport material Me-4PACz in IPA solution at a concentration of 1 mg / mL to obtain a hole transport material solution, and spin-coat the hole transport material solution on ITO transparent conductive glass. The spin-coating parameters are acceleration 1500 rpm / s, spin-coating speed 3000 rpm, and spin-coating time 30 s. Annealing is performed at an annealing temperature of 100°C and an annealing time of 10 min to obtain a 1 nm hole transport layer.

[0130] S3: preparing a perovskite layer on the hole transport layer, specifically including steps S31 and S32.

[0131] S31: PbI2 and CsI powders were mixed in a molar ratio of 100:5 and dissolved in a solvent (DMF:NMP = 5:1) to obtain an inorganic salt solution. The lead iodide concentration in the inorganic salt solution was 1 mol / L, and the cesium iodide concentration was 0.05 mol / L. The inorganic salt solution was spin-coated on the hole transport layer using the following spin-coating parameters: an acceleration of 1500 rpm / s, a spin-coating speed of 1500 rpm, and a spin-coating time of 15 seconds. A first annealing treatment was performed at a temperature of 75°C and a time of 1 minute, resulting in a 400 nm inorganic salt skeleton layer on the substrate.

[0132] S32: FAI, MABr, and MACl powders are mixed in a molar ratio of 10:1:1 and dissolved in ethanol to obtain an organic salt solution, wherein the concentration of FAI, MABr, and MACl in the organic salt solution is 0.6 mol / L, 0.06 mol / L, and 0.06 mol / L. The organic salt solution is spin-coated on the inorganic salt skeleton layer at an acceleration of 1500 rpm / s, a spin speed of 1700 rpm, and a spin coating time of 30 seconds. A second annealing treatment is performed at a temperature of 150°C and a time of 20 minutes to allow the inorganic salt skeleton layer to react with the organic salt solution to form a 650 nm perovskite layer.

[0133] S4: An electron transport layer is prepared on the perovskite layer. The electron transport material PCBM is dissolved in chlorobenzene at a concentration of 20 mg / mL to obtain an electron transport material solution. The electron transport material solution is spin-coated on the perovskite layer with the spin-coating parameters of acceleration 3000 rpm / s, spin-coating speed 5000 rpm, and spin-coating time 30 s. Annealing treatment is performed with an annealing temperature of 100°C and an annealing time of 10 min to obtain a 60 nm electron transport layer.

[0134] S5: A 6 nm BCP layer and a 150 nm back electrode (Au electrode) were sequentially deposited on the electron transport layer by vacuum evaporation.

[0135] Comparative Example 2

[0136] The perovskite solar cell of this comparative example was prepared by the following steps:

[0137] S1: Provide a substrate, clean the FTO transparent conductive glass, and blow dry it with nitrogen. Use a 1064nm wavelength laser to scribe the PI, and use magnetron sputtering to deposit a 25nm NiOx layer.

[0138] S2: Prepare a hole transport layer on the substrate, dissolve the hole transport material Me-4PACz in IPA solution at a concentration of 1 mg / mL to obtain a hole transport material solution, and coat the hole transport material solution on the NiOx layer by a slit coating method with the coating parameters of a coating speed of 30 mm / s and a liquid output of 350 μL. Annealing treatment is performed at an annealing temperature of 100°C and an annealing time of 10 min to obtain a 1 nm hole transport layer.

[0139] S3: preparing a perovskite layer on the hole transport layer, specifically including steps S31 and S32.

[0140] S31: PbI2 and CsI powders were mixed in a molar ratio of 100:5 and dissolved in a solvent (DMF:NMP = 5:1) to obtain an inorganic salt solution, wherein the concentration of lead iodide in the inorganic salt solution was 1 mol / L and the concentration of cesium iodide was 0.05 mol / L. The inorganic salt solution was coated on the hole transport layer by slit coating at a coating speed of 30 mm / s and a liquid output of 350 μL. Annealing was performed at a temperature of 75°C for 1 minute to obtain a 400 nm inorganic salt skeleton layer on the substrate.

[0141] S32: FAI, MABr, and MACl powders were mixed in a molar ratio of 10:1:1 and dissolved in 1 mL of ethanol to obtain an organic salt solution, wherein the concentration of FAI, MABr, and MACl in the organic salt solution was 0.6 mol / L, 0.06 mol / L, and 0.06 mol / L, respectively. The organic salt solution was coated on the inorganic salt skeleton layer by a slit coating method with coating parameters of a coating speed of 30 mm / s and a liquid output of 350 μL. An annealing treatment was performed at an annealing temperature of 150°C for 20 minutes to allow the inorganic salt skeleton layer to react with the organic salt solution to form a 650 nm perovskite layer.

[0142] S4: Prepare an electron transport layer on the perovskite layer and prepare a 15nm C 60 layer to obtain a 15 nm electron transport layer.

[0143] S3: A 20 nm SnO2 layer is prepared on the electron transport layer by ALD, and then P2 lines are scribed using a 532 nm wavelength laser.

[0144] S4: Prepare an ITO / Cu / ITO composite back electrode on the SnO2 layer using PVD, with thicknesses of 30nm / 100nm / 50nm respectively.

[0145] S5: Use a 532nm wavelength laser to scribe P3, use a 1064nm laser to clean the edges, and connect the lead segments.

[0146] Test example

[0147] The perovskite solar cells of the above examples and comparative examples were subjected to performance testing to determine their IV efficiency values. The test results are shown in Table 2.

[0148] The detection method is: using a solar simulator, under a standard sunlight intensity, to test the photoelectric conversion efficiency of the cell. The effective area of ​​Example 14 and Comparative Example 2 is 795 cm 2 , the test voltage range is: 60~-0.1V, the effective area of ​​other embodiments and comparative example 1 is 1cm 2 , the test voltage range is: 1.2~-0.1V.

[0149] Table 4 Test data of perovskite solar cells of Examples and Comparative Examples

[0150] From the experimental data in Table 4, we can see that:

[0151] 1. Comparing Example 1 with Comparative Example 1 and Example 14 with Comparative Example 2, the open circuit voltage and photoelectric conversion efficiency of Example 1 are slightly higher than those of Comparative Example 1, and the open circuit voltage and photoelectric conversion efficiency of Example 14 are slightly higher than those of Comparative Example 2. It can be seen that the composite perovskite film of the present application is applied to solar cells. On the basis of ensuring the performance of solar cells, it can save preparation steps, shorten the time required to prepare the battery, and improve the preparation efficiency. In addition, it can also improve the performance of solar cells to a certain extent.

[0152] 2. Comparing Examples 1 to 5, as the concentration of the hole transport material in the first mixed solution increases, the photoelectric conversion efficiency of the solar cell first increases and then decreases. It can be seen that in order to maintain a good photoelectric conversion efficiency, the concentration of the hole transport material in the first mixed solution is preferably 0.1 to 6 mg / mL, further preferably 0.3 to 1.5 mg / mL, and most preferably 1 mg / mL.

[0153] 3. Comparing Example 1 with Examples 6 to 9, as the concentration of the electron transport material in the second mixed solution increases, the photoelectric conversion efficiency of the solar cell first increases and then decreases. It can be seen that in order to maintain a good photoelectric conversion efficiency, the concentration of the electron transport material in the second mixed solution is preferably 0.1 to 10 mg / mL, and further preferably the concentration of the electron transport material in the second mixed solution is 2 to 6 mg / mL.

[0154] 4. Comparing Example 1 with Examples 11 to 13, the open circuit voltage, fill factor and photoelectric conversion efficiency of Examples 11 and 12 are higher than those of Example 1, and the open circuit voltage, fill factor and photoelectric conversion efficiency of Example 13 are higher than those of Examples 12 and 13. It can be seen that it is preferred to dope the first passivation material in the inorganic salt solution or the second passivation material in the organic salt solution, and it is most preferred to dope the first passivation material in the inorganic salt solution and the second passivation material in the organic salt solution at the same time to improve the passivation effect of the perovskite layer, thereby improving the performance of the solar cell.

[0155] Thus far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for preparing a composite perovskite film, characterized in that: The composite perovskite film comprises a hole transport layer, a perovskite layer and an electron transport layer which are sequentially distributed, and the preparation method comprises the following steps: Providing a first mixed solution consisting of a hole transport material and an inorganic salt solution; providing a second mixed solution consisting of an electron transport material and an organic salt solution; coating the first mixed solution on a substrate and performing a first annealing treatment to obtain a transition film on the substrate; wherein the transition film comprises a hole transport layer and an inorganic salt skeleton layer, and the hole transport layer is located between the substrate and the inorganic salt skeleton layer; The second mixed liquid is coated on the inorganic salt skeleton layer of the transition film, and a second annealing treatment is performed to allow the inorganic salt skeleton layer to react with the organic salt solution to form a perovskite layer, and at the same time, an electron transport layer is obtained on the side of the perovskite layer away from the hole transport layer, and a composite perovskite film is obtained on the substrate.

2. The method for preparing a composite perovskite thin film according to claim 1, wherein: The inorganic salt solution is a lead iodide solution, wherein the solvent in the lead iodide solution is one or more of dimethyl sulfoxide, N,N-dimethylformamide, acetonitrile, dimethylpyrrolidone, 2-methoxyethanol, and γ-butyrolactone; and / or, the concentration of the hole transport material in the first mixed solution is 0.1 to 6 mg / mL; preferably, the concentration of the hole transport material in the first mixed solution is 0.3 to 1.5 mg / mL; and / or, the hole transport material comprises a SAM material; And / or, the organic salt solution is an FAI solution, wherein the solvent in the FAI solution is one or more of ethanol, isopropanol, methanol, and dimethoxyethanol; and / or, the concentration of the electron transport material in the second mixed solution is 0.1 to 10 mg / mL; preferably, the concentration of the electron transport material in the second mixed solution is 2 to 6 mg / mL; And / or, the electron transport material is insoluble or slightly soluble in the organic salt solution.

3. The method for preparing a composite perovskite thin film according to claim 2, wherein: The concentration of lead iodide in the lead iodide solution is 0.5 to 1.5 mol / L; And / or, the inorganic salt solution is doped with a second inorganic salt, wherein the second inorganic salt comprises one or more of CsI, CsBr, CsCl, PbBr2, and PbCl2; And / or, the inorganic salt solution is further doped with a first passivation material, wherein the first passivation material comprises a potassium halide salt and / or a rubidium halide salt; and / or, the concentration of the FAI solution is 0.2 to 1.5 mol / L; and / or, the solvent in the FAI solution is ethanol; And / or, the organic salt solution is doped with a second organic salt, wherein the second organic salt comprises one or more of FABr, FACl, MAI, MABr, and MACl; And / or, the organic salt solution is doped with a second passivation material, and the second passivation material is PEAI and / or PMAI.

4. The method for preparing a composite perovskite thin film according to claim 3, wherein: The molar addition amount of the second inorganic salt is 0.05% to 5% of the lead iodide, preferably the molar addition amount of the second inorganic salt is 5% of the lead iodide; and / or, the molar addition amount of the first passivation material is 0.05% to 5% of the lead iodide; and / or, the concentration of the second organic salt in the organic salt solution is 0.05 to 1 mol / L; And / or, the molar addition amount of the second passivation material is 0.05% to 5% of the FAI.

5. The method for preparing a composite perovskite thin film according to claim 2, wherein: The SAM material includes one or more of MeO-2PACz, 2PACz, Me-2PACz, MeO-4PACz, Me-4PACz, and 4PACz; And / or, the electron transport material includes C 60 , PCBM, PTAA, SnO2 or more.

6. The method for preparing a composite perovskite thin film according to any one of claims 1 to 5, characterized in that: The first annealing temperature of the first annealing treatment is 50-100° C., and the first annealing time is 1-10 minutes; And / or, the second annealing temperature of the second annealing treatment is 100-160° C., and the second annealing time is 5-30 minutes.

7. A composite perovskite film, characterized in that: The composite perovskite film (2) comprises a hole transport layer (21), a perovskite layer (22) and an electron transport layer (23) distributed in sequence, and the composite perovskite film (2) is prepared by the composite perovskite film preparation method according to any one of claims 1 to 6.

8. A perovskite solar cell, characterized in that: The perovskite solar cell comprises, from bottom to top, a layered substrate (1), a composite perovskite film (2), a buffer layer (3) and a back electrode (4); the composite perovskite film (21) comprises, from bottom to top, a hole transport layer (21), a perovskite layer (22) and an electron transport layer (23); the composite perovskite film (2) is the composite perovskite film according to claim 7 or is prepared by the method for preparing a composite perovskite film according to any one of claims 1 to 6.

9. The perovskite solar cell according to claim 8, characterized in that The substrate (1) comprises one of ITO transparent conductive glass, FTO transparent conductive glass, IWO transparent conductive glass, and AZO transparent conductive glass; And / or, the back electrode (4) comprises a metal electrode or a metal oxide transparent electrode.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises the perovskite solar cell according to claim 8 or 9.

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