Perovskite precursor material, perovskite solar cell, preparation method and application

Abstract

The invention relates to a perovskite precursor material, a perovskite solar cell, a preparation method and application. The perovskite precursor material comprises a perovskite precursor and an additive, wherein the structural formula of the additive is as follows: # imgabs0 #; r1 to R6 are independently selected from one of hydrogen,-R7-C (= O)-R8,-R9-NO2, alkyl,-R10-X,-R11-CN,-R12-OH,-OSO2-OH and-OSO2-O-, R7 and R9-R12 are independently single bonds or alkylene, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O-, X is halogen, and at least one of R1 to R6 is-R9-NO2. The perovskite precursor material is applied to a perovskite solar cell, and the thermal stability of the perovskite solar cell is improved.

Description

Technical Field

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

[0002] In recent years, mixed metal halide perovskite has become one of the materials for preparing high-efficiency solar cells due to its excellent optoelectronic properties and easy manufacturing applicability. At the same time, it is exciting that its PCE (photovoltaic conversion efficiency) far exceeds that of other emerging thin-film solar cells and is comparable to the efficiency of commercial crystalline silicon solar cells.

[0003] However, despite their aforementioned technological advantages, the thermal stability of perovskite solar cells still needs to be improved. Summary of the invention

[0004] Based on this, some embodiments of the present application provide a perovskite precursor material, which is applied in perovskite solar cells to improve their thermal stability.

[0005] In addition, other embodiments of the present application also provide a perovskite solar cell and a preparation method thereof, and a photovoltaic module.

[0006] A perovskite precursor material includes a perovskite precursor and an additive, wherein the additive has the following structural formula: ;

[0007] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0008] In some embodiments, at least one of R1-R6 is -R7-C(=O)-R8.

[0009] In some embodiments, R1 is -R7-C(=O)-R8, and R4 is -R9-NO2.

[0010] In some embodiments, R1 is selected from -CHO, -C(=O)-CH3, -COOH, -COO - 、-CH2COO -, -CH2COOH and (COO)2 2- One of them.

[0011] In some embodiments, at least one of R2~R3 and R5~R6 is selected from chlorine; or, at least one of R2~R3 and R5~R6 is selected from C1~C6 alkyl.

[0012] In some embodiments, the structural formula of the additive is as follows:

[0013] , , , , .

[0014] In some of the embodiments, the mass ratio of the additive to the perovskite precursor is (0.5~1):100.

[0015] In some embodiments, the perovskite precursor includes ABX3, or the perovskite precursor includes BX2 and AX;

[0016] Among them, A includes FA + 、MA + , Cs + and DMA + One or more of B including Pb 2+ Sn 2+ and Bi 3+ One or more of X including I - Br - , Cl - and SCN - One or more of the .

[0017] A perovskite solar cell comprises a transparent conductive electrode, a perovskite layer and a counter electrode which are stacked;

[0018] The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ;

[0019] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O- , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0020] In some of the embodiments, a hole transport layer, an electron transport layer and a hole blocking layer are further included, wherein the hole transport layer is arranged between the transparent conductive electrode and the perovskite layer, and the electron transport layer and the hole blocking layer are arranged between the perovskite layer and the counter electrode.

[0021] In some of the embodiments, an interface modification layer is further included between the perovskite layer and the electron transport layer, and the material of the interface modification layer includes the additive.

[0022] A method for preparing a perovskite solar cell comprises the following steps:

[0023] preparing a stacked transparent conductive electrode, a perovskite layer, and a counter electrode;

[0024] The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ;

[0025] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0026] In some of the embodiments, the step of preparing the perovskite layer includes: coating the perovskite precursor material and the additive in the form of a solution on the surface of the transparent conductive electrode, annealing at 100°C~110°C for 5min~10min, heating to 130°C~150°C and annealing for 15min~20min to obtain the perovskite layer.

[0027] A photovoltaic module comprises the above-mentioned perovskite solar cell or a perovskite solar cell prepared by the above-mentioned preparation method.

[0028] The above-mentioned perovskite precursor material includes a perovskite precursor and an additive, wherein the additive contains at least one nitro group, and a nitro group in an additive can metal-chelate with a certain B-site atom on the lattice, such as a Pb atom. If an additive contains multiple nitro electron-donating groups or contains other electron-donating groups such as C=O and S=O in addition to the nitro group, each electron-donating group can metal-chelate with the Pb atom of the adjacent lattice structure, respectively, so as to promote the close contact of the adjacent lattice structures, and then multiple nitro groups or multiple electron-donating groups can react with the B-site atoms on multiple lattice structures to achieve the effect of binding them to the original lattice position, inhibiting the precipitation of BX2 such as lead iodide during the heating process, enhancing the charge transfer / extraction at the grain boundary, and can also react with the hole transport layer such as NiO x Reaction to reduce Ni 3+ The benzene ring can enhance the hydrophobicity of the perovskite film and reduce water erosion. Therefore, the above perovskite precursor materials are used in perovskite solar cells to improve the thermal stability of the battery and also improve the efficiency to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 A schematic diagram of the structure of a perovskite solar cell according to some embodiments of the present application;

[0031] Figure 2 A process flow chart of a method for preparing a perovskite solar cell according to some embodiments of the present application;

[0032] Figure 3 Fourier infrared images of the additive 4-formylbenzoic acid used in Example 2 and Example 6 and the perovskite film prepared after adding 4-formylbenzoic acid to the perovskite precursor solution;

[0033] Figure 4 Fourier infrared images of the additive 4-nitrobenzoic acid used in Example 3 and Example 7 and the perovskite film prepared after adding 4-nitrobenzoic acid to the perovskite precursor solution;

[0034] Figure 5 XRD patterns of the perovskite solar cells prepared in Example 6, Example 7, Example 8 and Comparative Example 2 after being heated at 85° C. for 1200 hours;

[0035] Figure 6This is a graph showing the efficiency stability of the perovskite solar cells prepared in Example 6, Example 7, Example 8 and Comparative Example 2 after being heated at 85° C. under nitrogen for 1200 hours;

[0036] Figure 7 This is a graph of the efficiency stability of the perovskite solar cells of Example 6, Example 7, Example 8 and Comparative Example 2 after being heated at 65% RH and 85° C. for 150 hours. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the specific embodiments. The preferred embodiments of the present application are provided in the specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] Unless otherwise specified or there is a contradiction, the terms and phrases used in this application have the following meanings:

[0040] In this application, "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0041] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0042] In this application, "one or several" refers to any one, any two or more of the listed items. Among them, "several" refers to any two or more of the listed items.

[0043] In this application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0044] The words "optionally" and the like in this application refer to embodiments of the present application that may provide certain beneficial effects in certain cases. However, other embodiments may also be optional under the same or other circumstances. In addition, the statement of one or more optional embodiments does not imply that other embodiments are unavailable, nor is it intended to exclude other embodiments from the scope of this application.

[0045] When a numerical range is disclosed in this application, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges included therein.

[0046] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0047] The terms "including" and "having" and any variations thereof in the embodiments of the present application 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 limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.

[0048] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0049] The term "alkyl" refers to a saturated hydrocarbon containing primary (normal) carbon atoms, or secondary carbon atoms, or tertiary carbon atoms, or quaternary carbon atoms, or a combination thereof. A phrase containing the term, for example, "C1-C9 alkyl" refers to an alkyl containing 1 to 9 carbon atoms, and each occurrence may be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl or C9 alkyl.

[0050] "Halogen" or "halo" refers to F, Cl, Br or I.

[0051] "Nitro" refers to the group remaining after removing a hydroxyl group from the nitric acid molecule, and its chemical formula is -NO2.

[0052] "Cyano" refers to a group in which a carbon atom and a nitrogen atom are connected by a triple bond, and its chemical formula is -CN.

[0053] "Hydroxy" refers to a monovalent atomic group consisting of an oxygen atom and a hydrogen atom connected, with the chemical formula -OH.

[0054] The first aspect of the present application provides a perovskite precursor material, including a perovskite precursor material and an additive, wherein the structural formula of the additive is as follows: ;

[0055] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, aminohydroxyl or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0056] The above-mentioned perovskite precursor material includes a perovskite precursor and an additive, wherein the additive contains at least one nitro group, and a nitro group in an additive can metal-chelate with a certain B-site atom on the lattice, such as a Pb atom. If an additive contains multiple nitro electron-donating groups or contains other electron-donating groups such as C=O and S=O in addition to the nitro group, each electron-donating group can metal-chelate with the Pb atom of the adjacent lattice structure, respectively, so as to promote the close contact of the adjacent lattice structures, and then multiple nitro groups or multiple electron-donating groups can react with the B-site atoms on multiple lattice structures to achieve the effect of binding them to the original lattice position, inhibiting the precipitation of BX2 such as lead iodide during the heating process, enhancing the charge transfer / extraction at the grain boundary, and can also react with the hole transport layer such as NiO x Reaction to reduce Ni 3+ The generation of vacancies, and the benzene ring can enhance the hydrophobicity of the perovskite film and reduce water erosion, so that the application of perovskite precursor materials in perovskite solar cells can improve the thermal stability of the battery and also improve the efficiency to a certain extent.

[0057] Experiments have shown that the perovskite solar cell prepared from the above perovskite precursor material can achieve a device efficiency of more than 60% on average after being heated at 85°C for 1200 hours. Furthermore, the perovskite solar cell prepared from the above perovskite precursor material can achieve a device efficiency of more than 70% on average after being heated at 85°C for 1200 hours. Furthermore, the perovskite solar cell prepared from the above perovskite precursor material can achieve a device efficiency of more than 80% on average after being heated at 85°C for 1200 hours.

[0058] In addition, the efficiency of the unpackaged device remains above 80% of the original device on average when heated at 65% humidity and 85°C for 150 hours. Furthermore, the efficiency of the unpackaged device remains above 85% of the original device on average when heated at 65% humidity and 85°C for 150 hours.

[0059] In some embodiments, at least two of R1 to R6 are -R9-NO2, or at least one of R1 to R6 is -R7-C(=O)-R8, -OSO2-OH, and -OSO2-O - If the additive contains multiple nitro electron-donating groups or contains other electron-donating groups such as C=O, S=O in addition to nitro groups, each electron-donating group can metal-chelate with the Pb atoms of the adjacent lattice structure, so that the adjacent lattice structures are in close contact, and multiple nitro groups or multiple electron-donating groups can react with the B-site atoms on multiple lattice structures to bind them to their original lattice positions.

[0060] In some embodiments, at least one of R1 to R6 is -R7-C(=O)-R8. Further, R1 is -R7-C(=O)-R8, and R4 is -R9-NO2.

[0061] In some embodiments, R1 is selected from -CHO, -C(=O)-CH3, -COOH, -COO - 、-CH2COO - , -CH2COOH and (COO)2 2- One of them.

[0062] In some embodiments, at least one of R2-R3 and R5-R6 is selected from alkyl, -R 10 -X, -R 11 -CN and -R 12 By introducing the above groups, the hydrophobicity of the perovskite film can be increased, the quality of the perovskite film can be improved, and the thermal / humidity stability of the device can be further improved.

[0063] In some embodiments, at least one of R2-R3 and R5-R6 is selected from chlorine. The Cl group can optimize the quality of the perovskite film during the growth process, reduce surface defects, and further improve the stability and photoelectric conversion efficiency of the device. In other embodiments, at least one of R2-R3 and R5-R6 is selected from C1-C6 alkyl. For example, at least one of R2-R3 and R5-R6 is selected from methyl.

[0064] In some embodiments, the additive has the following structural formula:

[0065] , , , , .

[0066] The above additives are easily available and have low purchase costs, which is beneficial to reducing production costs.

[0067] In some embodiments, the mass ratio of the additive to the perovskite precursor is (0.5-1): 100. For example, the mass ratio of the additive to the perovskite precursor may be, but is not limited to, 0.5:100, 0.6:100, 0.7:100, 0.8:100, 0.9:100, 1:100, or a range consisting of any two of these values.

[0068] In some embodiments, the perovskite precursor is ABX3, A includes FA + (formamidinium ion), MA + (methylamine ion), Cs + (cesium ion) and DMA + (dimethylamine ion) one or more, B includes Pb 2+ (Lead ion), Sn 2+ (tin ions) and Bi 3+ (bismuth ion) one or more. X includes I - (iodide ion), Br - (bromide ion), Cl - (chloride ion) and SCN - At this time, in the step of preparing the perovskite film from the perovskite precursor material, a one-step solution method is used.

[0069] In some embodiments, the perovskite precursor includes FA a Cs 1-a PbI3, where a is 0.9~0.95.

[0070] In some other embodiments, the perovskite precursor includes BX2 and AX, and A includes FA+ (formamidinium ion), MA + (methylamine ion), Cs + (cesium ion) and DMA + (dimethylamine ion) one or more, B includes Pb 2+ (Lead ion), Sn 2+ (tin ions) and Bi 3+ (bismuth ion) one or more. X includes I - (iodide ion), Br - (bromide ion), Cl - (chloride ion) and SCN - (thiocyanate ion) or more. For example, the perovskite precursor material includes PbI2 and AI. At this time, in the step of preparing the perovskite film from the perovskite precursor material, a two-step solution method or a thermal evaporation method is used to first prepare a BX2 film from part of the perovskite precursor, and then an AX solution is applied to prepare the perovskite layer.

[0071] A second aspect of the present application provides a perovskite solar cell, comprising a transparent conductive electrode, a perovskite layer and a counter electrode arranged in a stacked manner;

[0072] The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ;

[0073] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0074] The specific additives are as described in the first aspect above and will not be repeated here.

[0075] In some embodiments, in the perovskite layer, the additive is combined with the B-site atom in the ABX3 lattice. Further, in the perovskite layer, the additive is metal-chelated with the B-site atom in the ABX3 lattice.

[0076] It is understood that the transparent conductive electrode and the counter electrode may be commonly used in the art. For example, in some embodiments, the transparent conductive electrode includes but is not limited to transparent conductive glass. Specifically, the transparent conductive electrode is FTO (fluorine-doped tin oxide) or ITO (indium tin oxide). The counter electrode may be but is not limited to a metal electrode. Specifically, the counter electrode may be but is not limited to a silver electrode, a gold electrode, etc.

[0077] In some embodiments, the thickness of the counter electrode is 60 nm to 100 nm. For example, the thickness of the counter electrode can be, but is not limited to, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a range consisting of any two of these values.

[0078] In some embodiments, the thickness of the perovskite layer may be commonly used in the art, for example, the thickness of the perovskite layer is 400 nm to 500 nm.

[0079] In some embodiments, the perovskite solar cell further comprises a hole transport layer, an electron transport layer and a hole blocking layer, wherein the hole transport layer is disposed between the transparent conductive electrode and the perovskite layer, and the electron transport layer and the hole blocking layer are disposed between the perovskite layer and the counter electrode.

[0080] In some embodiments, the material of the hole transport layer may be, but is not limited to, a metal oxide. For example, the material of the hole transport layer is NiO x .

[0081] In some embodiments, the material of the electron transport layer is, but is not limited to, C 60 .

[0082] In some embodiments, the thickness of the electron transport layer is 25 nm to 35 nm. For example, the thickness of the electron transport layer can be, but is not limited to, 25 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 35 nm, or a range consisting of any two of these values.

[0083] In some embodiments, the material of the hole blocking layer may be, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0084] In some embodiments, the thickness of the hole blocking layer is 4 nm to 7 nm. For example, the thickness of the hole blocking layer can be, but is not limited to, 4 nm, 5 nm, 6 nm, 7 nm, or a range consisting of any two of these values.

[0085] It can be understood that only a few more specific materials and thicknesses of each layer are given above, but it is not limited thereto.

[0086] Specifically, see Figure 1 The perovskite solar cell includes a transparent conductive electrode 110, a hole transport layer 120, a perovskite layer 130, an electron transport layer 140, a hole blocking layer 150 and a counter electrode 160 which are stacked in sequence.

[0087] In some of the embodiments, the perovskite solar cell further comprises an interface modification layer disposed between the perovskite layer and the electron transport layer, and the material of the interface modification layer comprises the additive. Experiments have shown that the above-mentioned additives can not only be used for doping in perovskite precursor materials, but also for interface modification, and the synergistic effect of the two can be used to further improve the thermal stability of the perovskite solar cell and increase the practicality and convenience of the experiment. At the same time, it can avoid the introduction of new defects by not using additives for interface modification and perovskite doping. By providing an interface modification layer between the perovskite layer and the electron transport layer, the difference in thermal expansion coefficients between different deposited layers can be reduced and the defects of the electron transport layer can be passivated, thereby further improving the thermal stability and photoelectric conversion efficiency.

[0088] In some embodiments, the thickness of the interface modification layer is 4 nm to 10 nm. For example, the thickness of the interface modification layer can be, but is not limited to, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, or a range consisting of any two of these values.

[0089] The third aspect of the present application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0090] preparing a stacked transparent conductive electrode, a perovskite layer, and a counter electrode;

[0091] The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ;

[0092] R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

[0093] In some embodiments, in the step of preparing the perovskite layer, a solution method or a thermal evaporation method can be used. Among them, the solution method includes a one-step solution method or a two-step solution method. When the one-step solution method is used, the perovskite precursor is ABX3, and the perovskite precursor material is applied to the surface of the transparent conductive electrode in the form of a solution, and then extracted with an anti-solvent such as chlorobenzene, ether, etc., annealed, and the perovskite layer is prepared. In the two-step solution method, part of the perovskite precursor material is first formed into a BX2 film, and then the AX solution is added dropwise to prepare the perovskite layer. The specific method can be a spin coating method or a slit coating method, etc.

[0094] The following describes in detail the steps of preparing the perovskite layer by taking the one-step solution method as an example, but is not limited thereto.

[0095] The steps of preparing the perovskite layer include: coating the perovskite precursor and additives on the surface of the transparent conductive electrode in the form of a solution, annealing at 100°C to 110°C for 5min to 10min, heating to 130°C to 150°C and annealing for 15min to 20min to obtain the perovskite layer.

[0096] By adopting a two-step annealing process, it is beneficial to make the nitro or carbonyl in the additive preferentially coordinate with the B-site ions such as lead ions in the lattice, further improving the stability. It is understood that in some other embodiments, a one-step annealing method can also be adopted, for example, annealing at 130° C. to 150° C. for 15 min to 20 min.

[0097] In some of these embodiments, the annealing is performed in a non-nitrogen environment.

[0098] In some embodiments, the perovskite layer is prepared by spin coating, the spin coating speed is 5000rpm~6000rpm, and the spin coating time is 30s~40s. For example, the spin coating speed can be but not limited to 5000rpm, 5200rpm, 5400rpm, 5500rpm, 5600rpm, 5800rpm, 6000rpm or a range consisting of any two of these values. The spin coating time can be but not limited to 30s, 32s, 34s, 35s, 36s, 38s, 40s or a range consisting of any two of these values.

[0099] In some of the embodiments, the perovskite layer can be prepared in a non-nitrogen environment with a humidity of 20% RH to 30% RH and a temperature of 20° C. to 23° C.

[0100] In some embodiments, in the step of preparing the perovskite layer, the solvent used includes one or more of DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone) and acetonitrile. In one embodiment, in the step of preparing the perovskite layer, the volume ratio of DMF, DMSO, NMP and acetonitrile in the solvent used is 4: (1-xy): x: y. Wherein, x is 0~0.3 and y is 0~0.1. For example, x can be, but not limited to, 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 or a range consisting of any two of these values. y can be, but not limited to, 0, 0.01, 0.02, 0.04, 0.05, 0.06, 0.08, 0.1 or a range consisting of any two of these values.

[0101] In some embodiments, the perovskite precursor is mixed with a solvent, and an additive is added and mixed. After the additive is completely dissolved, a perovskite precursor solution is prepared. In some embodiments, the additive is added to the perovskite precursor solution 20 minutes to 30 minutes before use. The above arrangement is conducive to preventing the BX2 material from deteriorating and stabilizing the pH.

[0102] In some embodiments, the perovskite solar cell further includes a hole transport layer, an electron transport layer, a hole blocking layer, and a counter electrode.

[0103] See also Figure 2 , a method for preparing a perovskite solar cell comprises the following steps:

[0104] Step S210: forming a hole transport layer on the surface of the transparent conductive electrode.

[0105] In some embodiments, the transparent conductive electrode includes but is not limited to transparent conductive glass, for example, the transparent conductive electrode is FTO (fluorine-doped tin oxide) or ITO (indium tin oxide).

[0106] In some embodiments, the material of the hole transport layer may be, but is not limited to, metal oxide, for example, NiOx.

[0107] In some embodiments, a solution method is used to form a hole transport layer. For example, the material of the hole transport layer is mixed with a solvent, the mixed solution is applied to the surface of the transparent conductive electrode, and annealed to prepare the hole transport layer. In a specific example, in the annealing step, annealing is performed at 130° C. to 150° C. for 15 min to 20 min.

[0108] Step S220: forming a perovskite layer on the surface of the hole transport layer.

[0109] The specific steps for preparing the perovskite layer are as described above and will not be repeated here.

[0110] Step S230: forming an electron transport layer on the surface of the perovskite layer.

[0111] In some embodiments, the electron transport layer is formed by evaporation.

[0112] In some embodiments, the material of the electron transport layer is, but is not limited to, C 60 .

[0113] In some embodiments, the thickness of the electron transport layer is 25 nm to 35 nm. For example, the thickness of the electron transport layer can be, but is not limited to, 25 nm, 26 nm, 28 nm, 30 nm, 32 nm, 34 nm, 35 nm, or a range consisting of any two of these values.

[0114] Step S240: forming a hole blocking layer on the surface of the electron transport layer.

[0115] In some embodiments, the material of the hole blocking layer may be, but is not limited to, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline).

[0116] In some embodiments, the hole blocking layer is formed by thermal evaporation.

[0117] In some embodiments, the thickness of the hole blocking layer is 4 nm to 7 nm. For example, the thickness of the hole blocking layer can be, but is not limited to, 4 nm, 5 nm, 6 nm, 7 nm, or a range consisting of any two of these values.

[0118] Step S250: forming a counter electrode on the surface of the hole blocking layer to prepare a perovskite solar cell.

[0119] In some embodiments, the counter electrode may be, but is not limited to, a metal electrode. Specifically, the counter electrode may be, but is not limited to, a silver electrode, a gold electrode, or the like.

[0120] In some embodiments, the counter electrode is formed by evaporation.

[0121] In some embodiments, the thickness of the counter electrode is 60 nm to 100 nm. For example, the thickness of the counter electrode can be, but is not limited to, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, or a range consisting of any two of these values.

[0122] Understandably, Figure 2 This is a schematic diagram of a process for preparing a perovskite solar cell according to an embodiment of the present invention. Figure 2The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and they can be performed in other orders. Figure 2 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The order of execution is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of other sub-steps or stages.

[0123] It can be understood that the above only provides several common materials, thicknesses, preparation processes, etc. of each layer, but is not limited thereto.

[0124] The preparation method of the perovskite solar cell is simple in process and easy to industrialize.

[0125] In some embodiments, the perovskite solar cell further comprises an interface modification layer disposed between the perovskite layer and the electron transport layer, and the material of the interface modification layer comprises the additive. The above-mentioned additive can not only be used for doping in the perovskite precursor material, but also for interface modification, and the synergistic effect of the two can be used to further improve the thermal stability of the perovskite solar cell and increase the practicality and convenience of the experiment. At the same time, it can avoid the interface modification and perovskite doping using no additives to introduce new defects.

[0126] In some of the embodiments, the step of preparing the interface modification layer includes: applying a solution containing an additive to the surface of the perovskite film to prepare the interface modification layer.

[0127] The solvent used in the solution containing the additive is the same as the solvent used in the perovskite precursor solution.

[0128] A fourth aspect of the present application provides a photovoltaic module, comprising the above-mentioned perovskite solar cell.

[0129] It is understood that the photovoltaic module also includes photovoltaic glass, photovoltaic backplane, photovoltaic film, etc. In some embodiments, the photovoltaic module includes photovoltaic glass, a first photovoltaic film, a perovskite solar cell, a second photovoltaic film and a photovoltaic backplane stacked in sequence.

[0130] In order to make the purpose and advantages of the present application clearer, the perovskite solar cell of the present application and its effects are further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and shall not be used to limit the present application. The following embodiments do not include other components except for unavoidable impurities unless otherwise specified. The drugs and instruments used in the embodiments are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the embodiments are implemented according to conventional conditions, such as the conditions described in the literature and books or the methods recommended by the manufacturer.

[0131] Example 1

[0132] This embodiment provides a perovskite solar cell, and the preparation steps are as follows:

[0133] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0134] (2) NiO x Powder NiO x The mixture was mixed with deionized water in a mass ratio of 1:80, and the mixed solution was repeatedly sonicated 3 times with an ultrasonic machine, each time for 5 minutes, to obtain a hole transport layer solution.

[0135] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 min, and then the hole transport layer solution was spin-coated at a speed of 4000 rpm for 25 s and annealed at 150 °C for 15 min to prepare NiO x Hole transport layer.

[0136] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and 4-ethylnitrobenzene (ECB) was added thereto. 0.9 Cs 0.1 The mass ratio of PbI3 is 0.5:100, stirred at room temperature until completely dissolved, and FA is obtained by filtration. 0.9 Cs 0.1 PbI3-ECB perovskite precursor solution.

[0137] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1The PbI3-ECB perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-ECB perovskite layer.

[0138] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-ECB perovskite layer as an electron transport layer.

[0139] (7) BCP is thermally evaporated again on the electron transport layer in step (6). BCP mainly serves as a hole blocking layer to prevent electron-hole recombination.

[0140] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0141] Example 2

[0142] This embodiment provides a solar cell, and the preparation steps are as follows:

[0143] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0144] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0145] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 min, and then the hole transport layer solution was spin-coated at a speed of 4000 rpm for 25 s and annealed at 150 °C for 15 min to prepare NiO x Hole transport layer.

[0146] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1The mass ratio of PbI3 to 4-formylbenzoic acid (BAC) was 1:100, stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BAC perovskite precursor solution.

[0147] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BAC perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BAC perovskite layer.

[0148] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BAC perovskite layer as an electron transport layer.

[0149] (7) BCP is thermally evaporated again on the electron transport layer in step (6). BCP mainly serves as a hole blocking layer to prevent electron-hole recombination.

[0150] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , gold with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0151] Example 3

[0152] This embodiment provides a solar cell, and the preparation steps are as follows:

[0153] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0154] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0155] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0156] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 4-nitrobenzoic acid (BAC(N)) with a mass ratio of 0.73:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BAC(N) perovskite precursor solution.

[0157] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BAC (N) perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BAC(N) perovskite layer.

[0158] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BAC (N) perovskite layer as an electron transport layer.

[0159] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0160] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0161] Example 4

[0162] This embodiment provides a solar cell, and the preparation steps are as follows:

[0163] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0164] (2) NiO x Powder NiO xThe mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0165] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0166] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 2-Chloro-4-nitrobenzoic acid (BACN(Cl)) with a mass ratio of 0.5:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BACN(Cl) perovskite precursor solution.

[0167] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BACN (Cl) perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BACN(Cl) perovskite layer.

[0168] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BACN (Cl) perovskite layer as an electron transport layer.

[0169] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0170] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0171] Example 5

[0172] This embodiment provides a perovskite solar cell, and the preparation steps are as follows:

[0173] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0174] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0175] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 min, and then the hole transport layer solution was spin-coated at a speed of 4000 rpm for 25 s and annealed at 150 °C for 15 min to prepare NiO x Hole transport layer.

[0176] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 4-Ethylnitrobenzene (ECB) with a mass ratio of 0.5:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-ECB perovskite precursor solution.

[0177] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-ECB perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-ECB perovskite layer.

[0178] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-ECB perovskite layer as an electron transport layer.

[0179] (7) BCP is thermally evaporated again on the electron transport layer in step (6). BCP mainly serves as a hole blocking layer to prevent electron-hole recombination.

[0180] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm as the metal anode, and the perovskite solar cell is obtained

[0181] Example 6

[0182] This embodiment provides a solar cell, and the preparation steps are as follows:

[0183] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0184] (2) NiO x Powder NiO x The mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0185] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 min, and then the hole transport layer solution was spin-coated at a speed of 4000 rpm for 25 s and annealed at 150 °C for 15 min to prepare NiO x Hole transport layer.

[0186] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 The mass ratio of PbI3 to 4-formylbenzoic acid (BAC) was 1:100, stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BAC perovskite precursor solution.

[0187] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BAC perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA.0.9 Cs 0.1 PbI3-BAC perovskite layer.

[0188] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BAC perovskite layer as an electron transport layer.

[0189] (7) BCP is thermally evaporated again on the electron transport layer in step (6). BCP mainly serves as a hole blocking layer to prevent electron-hole recombination.

[0190] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , gold with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0191] Example 7

[0192] This embodiment provides a solar cell, and the preparation steps are as follows:

[0193] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0194] (2) NiO x Powder NiO x The mixture was mixed with deionized water in a mass ratio of 1:80, and the mixed solution was repeatedly sonicated 3 times with an ultrasonic machine, each time for 5 minutes, to obtain a hole transport layer solution.

[0195] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0196] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 4-nitrobenzoic acid (BAC(N)) with a mass ratio of 0.73:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1PbI3-BAC(N) perovskite precursor solution.

[0197] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BAC (N) perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BAC(N) perovskite layer.

[0198] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BAC (N) perovskite layer as an electron transport layer.

[0199] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0200] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0201] Example 8

[0202] This embodiment provides a solar cell, and the preparation steps are as follows:

[0203] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0204] (2) NiO x Powder NiO x The mixture was mixed with deionized water in a mass ratio of 1:80, and the mixed solution was repeatedly sonicated 3 times with an ultrasonic machine, each time for 5 minutes, to obtain a hole transport layer solution.

[0205] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0206] (4) 1.5 mol FA 0.9 Cs0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 2-Chloro-4-nitrobenzoic acid (BACN(Cl)) with a mass ratio of 0.5:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BACN(Cl) perovskite precursor solution.

[0207] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BACN (Cl) perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BACN(Cl) perovskite layer.

[0208] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BACN (Cl) perovskite layer as an electron transport layer.

[0209] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0210] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0211] Example 9

[0212] This embodiment provides a solar cell, and the preparation steps are as follows:

[0213] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0214] (2) NiO x Powder NiO xThe mixed solution was ultrasonicated 3 times with an ultrasonic machine for 5 min each time to obtain a hole transport layer solution.

[0215] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0216] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), and FA was added to the solution. 0.9 Cs 0.1 4-nitrobenzoic acid (BAC(N)) with a mass ratio of 0.73:100 to PbI3 was stirred at room temperature until completely dissolved, and FA was obtained by filtration. 0.9 Cs 0.1 PbI3-BAC(N) perovskite precursor solution.

[0217] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3-BAC (N) perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3-BAC(N) perovskite layer.

[0218] (6) Dissolve 4-nitrobenzoic acid and chlorobenzene in a ratio of 1:1000 and spin coat them onto the FA 0.9 Cs 0.1 A BAC(N) interface modification layer was prepared on the PbI3-BAC(N) perovskite layer.

[0219] (7) FA obtained in step (6) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3-BAC (N) perovskite layer as an electron transport layer.

[0220] (8) BCP thermal evaporation is performed again on the electron transport layer in step (7). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0221] (9) The effective area of ​​evaporation on the BCP barrier layer prepared in step (8) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0222] Comparative Example 1

[0223] Comparative Example 1 provides a perovskite solar cell, and the preparation steps are as follows:

[0224] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0225] (2) NiO x Powder NiO x The mixture was mixed with deionized water in a mass ratio of 1:80, and the mixed solution was repeatedly sonicated 3 times with an ultrasonic machine, each time for 5 minutes, to obtain a hole transport layer solution.

[0226] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0227] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), stirred at room temperature until completely dissolved, and filtered to obtain FA 0.9 Cs 0.1 PbI3 perovskite precursor solution.

[0228] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3 perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and annealed at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3 perovskite layer.

[0229] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3 perovskite layer as an electron transport layer.

[0230] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0231] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0232] Comparative Example 2

[0233] Comparative Example 2 provides a perovskite solar cell, and the preparation steps are as follows:

[0234] (1) Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water and alcohol respectively. Each cleaning time is 15 minutes. After cleaning, use a N2 gun to blow dry and set aside.

[0235] (2) NiO x Powder NiO x The mixture was mixed with deionized water in a mass ratio of 1:80, and the mixed solution was repeatedly sonicated 3 times with an ultrasonic machine, each time for 5 minutes, to obtain a hole transport layer solution.

[0236] (3) The clean and ready-to-use FTO conductive substrate in step (1) was treated with UV-zone for 20 minutes, and then spin-coated with the hole transport layer solution at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 15 minutes to prepare NiO x Hole transport layer.

[0237] (4) 1.5 mol FA 0.9 Cs 0.1 PbI3 powder was dissolved in 1 mL of an organic solvent with a volume ratio of DMF:DMSO:NMP=4:1-x:x (x is 0.2), stirred at room temperature until completely dissolved, and filtered to obtain FA 0.9 Cs 0.1 PbI3 perovskite precursor solution.

[0238] (5) Take 100 μL of the FA prepared in step (4) 0.9 Cs 0.1 The PbI3 perovskite precursor solution is added dropwise to the surface of the hole transport layer in step (3), extracted with an anti-solvent, and then pre-annealed at 100°C for 7 minutes, followed by annealing at 150°C for 15 minutes to obtain FA. 0.9 Cs 0.1 PbI3 perovskite layer.

[0239] (6) FA obtained in step (5) 0.9 Cs 0.1 A 25 nm thick C60 was thermally evaporated on the surface of the PbI3 perovskite layer as an electron transport layer.

[0240] (7) BCP is thermally evaporated again on the electron transport layer in step (6). The main function of BCP is to act as a hole blocking layer to prevent electron-hole recombination.

[0241] (8) The effective area of ​​evaporation on the BCP barrier layer prepared in step (7) is 0.071 cm 2 , silver with a thickness of 100nm is used as the metal anode to obtain a perovskite solar cell.

[0242] The short-circuit current (J) of the perovskite solar cells of the above-mentioned embodiments and comparative examples is sc )、Open circuit voltage(V oc ), fill factor (FF) and photoelectric conversion efficiency (PCE) were tested, and the experimental data shown in Table 1 were obtained. Among them, the fill factor (FF) refers to the actual maximum obtainable power (P m or V mp * J mp ) and theoretical (not actually achievable) power (J sc * V oc ). Therefore, FF can be determined by the following formula:

[0243] FF = (V mp * J mp ) / (J sc * V oc ).

[0244] Among them J mp and V mp Respectively represent the maximum power point (P m ) is obtained by changing the resistance in the circuit until J*V reaches its maximum value; J sc and V oc They represent short circuit current and open circuit voltage respectively. Open circuit voltage (Voc) is the potential difference between the anode and cathode of the device when there is no external load connected.

[0245] The PCE of a solar cell refers to the percentage of power converted from absorbed light to electrical energy. The PCE of a solar cell can be measured by the incident light irradiance (E: W / m 2 ) and the surface area of ​​the solar cell (Ac:m 2 ) except the maximum power point (P mSTC is usually calculated at a temperature of 25°C and a radiation intensity of 1000 W / m 2 , the spectrum of air quality 1.5 (AM1.5).

[0246] Table 1 Performance parameters of perovskite solar cells of embodiments and comparative examples

[0247]

[0248] It can be seen from Table 1 above that by doping the perovskite layer with additives, the photoelectric conversion efficiency of the solar cell prepared in the embodiment is significantly better than that in the comparative example. And by optimizing the annealing process during the preparation of the perovskite layer, it is beneficial to further improve the performance of the solar cell. In addition, by optimizing the structure of the additive, the performance of the solar cell can also be further improved.

[0249] Figure 3 The following are Fourier infrared images of the 4-formylbenzoic acid used in Example 2 and the perovskite film prepared by adding 4-formylbenzoic acid to the perovskite precursor solution. Figure 3 It can be clearly observed that after doping with 4-formylbenzoic acid, the C=O functional group shifts, which means that the C=O in 4-formylbenzoic acid undergoes a metal chelation reaction with Pb, binding Pb to its original lattice position.

[0250] Figure 4 The following are Fourier transform infrared images of the additive 4-nitrobenzoic acid used in Example 3 and the perovskite film prepared after adding 4-nitrobenzoic acid to the perovskite precursor solution. Figure 4 It can be clearly observed that after 4-nitrobenzoic acid doping, the C=O functional group shifts, which means that C=O and Pb undergo a metal chelation reaction, binding Pb to its original lattice position. Figure 3 and Figure 4 , it can also be seen that in Figure 3 The C=O functional group in Figure 4 The displacement of C=O functional group in 4-formylbenzoic acid is slightly smaller, so the binding ability of 4-formylbenzoic acid with Pb is less than that of 4-nitrobenzoic acid with Pb. This is mainly because N=O in 4-nitrobenzoic acid has a certain electron-donating ability with Pb. 2+ reaction.

[0251] Figure 5 The XRD patterns of the perovskite solar cells prepared in Example 6, Example 7, Example 8 and Comparative Example 2 after being heated at 85°C for 1200 hours. Figure 5It can be observed that Example 7 and Example 8 have different degrees of deviation to large angles, indicating that the reaction of C=O and N=O in the additive with Pb in the lattice causes the perovskite lattice to shrink, reduces lattice distortion, and makes the lattice structure more stable. Compared with Example 6 and Comparative Example 2, the additive 4-nitrobenzoic acid in Example 7 and the additive 2-chloro-4-nitrobenzoic acid in Example 8 can reduce the generation of lead iodide during heating, which shows that using them for bulk doping can play a better thermal stabilization role. Compared with Comparative Example 2, the generation of lead iodide in Example 6 is also reduced, indicating that a single C=O functional group can also play a role in binding Pb atoms, but because the electron supply capacity of a single group is limited, its binding capacity is not as good as that of Example 7 and Example 8.

[0252] Figure 6 The efficiency stability diagram of the perovskite solar cells prepared in Example 6, Example 7, Example 8 and Comparative Example 2 after being heated at 85°C and nitrogen for 1200 hours. It can be seen from the figure that the thermal stability of Example 6, Example 7 and Example 8 is significantly better than that of Comparative Example 2 after being heated at 85°C and nitrogen for 1200 hours. And the thermal stability of Example 7 and Example 8 is better than that of Example 6.

[0253] Figure 7 The efficiency stability diagram of the perovskite solar cells prepared in Example 6, Example 7, Example 8 and Comparative Example 2 after heating at 65% RH and 85° C. for 150 hours is shown in FIG. Figure 7 It can be seen that after heating at 65% RH and 85°C for 150 hours, the stability of Example 6, Example 7, and Example 8 is significantly better than that of Comparative Example 2, and the thermal stability of Example 7 and Example 8 is better than that of Example 6.

[0254] It can be seen from the above experimental data that adding additives to the perovskite precursor solution is beneficial to improving the thermal stability of perovskite solar cells, and at the same time, it also improves the photoelectric conversion efficiency to a certain extent.

[0255] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0256] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A perovskite precursor material, characterized in that: It includes a perovskite precursor and an additive, and the structural formula of the additive is as follows: ; R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

2. The perovskite precursor material according to claim 1, characterized in that At least one of R1 to R6 is -R7-C(=O)-R8.

3. The perovskite precursor material according to claim 2, characterized in that: R1 is -R7-C(=O)-R8, and R4 is -R9-NO2.

4. The perovskite precursor material according to claim 3, characterized in that: R1 is selected from -CHO, -C(=O)-CH3, -COOH, -COO - 、-CH2COO - , -CH2COOH and (COO)2 2- One of them.

5. The perovskite precursor material according to claim 4, characterized in that: At least one of R2~R3 and R5~R6 is selected from chlorine; or at least one of R2~R3 and R5~R6 is selected from C1~C6 alkyl.

6. The perovskite precursor material according to claim 1, characterized in that: The structural formula of the additive is as follows: 、 、 、 、 。 7. The perovskite precursor material according to any one of claims 1 to 6, characterized in that: The mass ratio of the additive to the perovskite precursor is (0.5~1):

100.

8. The perovskite precursor material according to any one of claims 1 to 6, characterized in that: The perovskite precursor includes ABX3, or the perovskite precursor includes BX2 and AX; Among them, A includes FA + 、MA + , Cs + and DMA + One or more of B including Pb 2+ Sn 2+ and Bi 3+ One or more of X including I - Br - , Cl - and SCN - One or more of the .

9. A perovskite solar cell, characterized in that: It includes a transparent conductive electrode, a perovskite layer and a counter electrode which are stacked; The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ; R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

10. The perovskite solar cell according to claim 9, characterized in that: It also includes a hole transport layer, an electron transport layer and a hole blocking layer, wherein the hole transport layer is arranged between the transparent conductive electrode and the perovskite layer, and the electron transport layer and the hole blocking layer are arranged between the perovskite layer and the counter electrode.

11. The perovskite solar cell according to claim 10, characterized in that: The method further comprises an interface modification layer disposed between the perovskite layer and the electron transport layer, wherein the material of the interface modification layer comprises the additive.

12. A method for preparing a perovskite solar cell, characterized in that: The steps include: preparing a stacked transparent conductive electrode, a perovskite layer, and a counter electrode; The material of the perovskite layer includes ABX3 and an additive, and the structural formula of the additive is as follows: ; R1 to R6 are each independently selected from hydrogen, -R7-C(=O)-R8, -R9-NO2, alkyl, -R 10 -X, -R 11 -CN, -R 12 -OH, -OSO2-OH and -OSO2-O - One of R7 and R9~R 12 Each is independently a single bond or an alkylene group, R8 is hydrogen, alkoxy, alkyl, hydroxyl, amino or O - , X is a halogen, and at least one of R1 to R6 is -R9-NO2.

13. The method for preparing a perovskite solar cell according to claim 12, characterized in that: The steps of preparing the perovskite layer include: coating the perovskite precursor and the additive in the form of a solution on the surface of the transparent conductive electrode, annealing at 100°C to 110°C for 5min to 10min, heating to 130°C to 150°C and annealing for 15min to 20min to obtain the perovskite layer.

14. A photovoltaic module, characterized in that: A perovskite solar cell comprising the perovskite solar cell according to any one of claims 9 to 11 or a perovskite solar cell prepared by the preparation method according to any one of claims 12 to 13.

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