Perovskite solar cell, manufacturing method therefor and use thereof

Abstract

The present application provides a perovskite solar cell, a manufacturing method therefor, and the use thereof. The perovskite solar cell comprises a first electrode, a perovskite light-absorbing layer, a passivation layer, and a second electrode. The passivation layer comprises a passivating agent, the passivating agent comprising a positively charged group and an electron-rich group; the positively charged group comprises -NH3X, where X comprises any one of halogen, pseudohalogen, and -COOR, and R comprises any one of C1-C6 alkyl groups; and the electron-rich group comprises any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

Description

Perovskite solar cells, their fabrication methods and applications

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese patent application 202411744775.x, filed on November 29, 2024, entitled "Perovskite Solar Cells, Methods for Fabrication Thereof and Applications", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a perovskite solar cell, its preparation method and application. Background Technology

[0004] In perovskite solar cells, the quality of the photoactive layer, the perovskite thin film, has a decisive impact on the photoelectric conversion efficiency. However, perovskite crystals inevitably contain intrinsic defects (such as vacancy defects, interstitial defects, substitution defects, and antisite defects). Furthermore, the formation of defect states on the perovskite surface can lead to nonradiative recombination of charge carriers, thus limiting the photoelectric conversion efficiency. Therefore, it is necessary to find suitable passivating agents to passivate defects on the perovskite surface and reduce the loss of effective charge carriers caused by nonradiative recombination. Summary of the Invention

[0005] This application provides a perovskite solar cell, its fabrication method, a photovoltaic system, an electrical device, and a power generation device to improve the photoelectric conversion efficiency of perovskite solar cells.

[0006] The first aspect of this application provides a perovskite solar cell, comprising a first electrode, a perovskite light-absorbing layer, a passivation layer, and a second electrode. The passivation layer comprises a passivating agent, which includes a positively charged group and an electron-rich group. The positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

[0007] The passivating agent of this application has positively charged groups and electron-rich groups, that is, it is a bifunctional passivating agent. The positively charged groups reduce the carrier recombination centers caused by positively charged defects, and the negatively charged groups reduce the reverse built-in electric field caused by negatively charged defects, thereby effectively improving the open-circuit voltage and fill factor of the perovskite solar cell, and thus improving the photoelectric conversion efficiency of the perovskite solar cell. In addition, the aforementioned electron-rich groups can also adjust the dipole moment of the passivating agent, enhance the field-effect passivation effect, and make the improvement of photoelectric conversion efficiency more significant.

[0008] In any embodiment of the first aspect of this application, the positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, R includes a C1-C3 alkyl group, the halogen includes any one of Cl, Br, and I, the pseudohalogen includes -SCN, and the electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH.

[0009] In any embodiment of the first aspect of this application, the positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOCH3, and -SCN, and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH.

[0010] In any embodiment of the first aspect of this application, the positively charged group includes -NH3X, where X includes any one of Cl, Br, and I, and the electron-rich group includes any one of -CF3, -SCH3, and -SH.

[0011] In any embodiment of the first aspect of this application, the passivating agent comprises a compound with the structure shown in Formula I, R 1 -R 3 -R 2 Structural Formula I

[0012] in,

[0013] R 1 R is a positively charged group. 2 R is an electron-rich group. 3 It is a C2-C8 alkylene group.

[0014] In any embodiment of the first aspect of this application, R 3 It is a C3-C5 alkylene group.

[0015] In any embodiment of the first aspect of this application, the passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, and INH3-(CH2)5-SCH3. Any one or more of the following: INH3-(CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, CH3COONH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH.

[0016] In any embodiment of the first aspect of this application, the surface of the perovskite light-absorbing layer has lead halide, and the mass ratio of passivating agent to lead halide is 6:1-60:1.

[0017] In any embodiment of the first aspect of this application, the perovskite solar cell further includes a first charge transport layer and a second charge transport layer. The first charge transport layer is disposed between the first electrode and the perovskite light-absorbing layer, and the second charge transport layer is disposed between the passivation layer and the second electrode. One of the first charge transport layer and the second charge transport layer is a hole transport layer and the other is an electron transport layer.

[0018] In any embodiment of the first aspect of this application, the first electrode is a transparent conductive electrode, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer.

[0019] A second aspect of this application provides a method for fabricating a perovskite solar cell. The method includes fabricating a perovskite light-absorbing layer, a passivation layer, and a second electrode on a first electrode. The step of fabricating the passivation layer includes:

[0020] A passivating agent solution is placed on a perovskite light-absorbing layer and annealed to obtain a passivating layer. The passivating agent includes a positively charged group and an electron-rich group. The positively charged group is selected from -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

[0021] In any embodiment of the second aspect of this application, the positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, R includes a C1-C3 alkyl group, the halogen includes any one of Cl, Br, and I, the pseudohalogen includes -SCN, and the electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH.

[0022] In any embodiment of the second aspect of this application, the positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOH3, and -SCN, and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH.

[0023] In any embodiment of the second aspect of this application, the positively charged group is selected from -NH3X, where X is selected from any one of Cl, Br, and I, and the electron-rich group is selected from any one of -CF3, -SCH3, and -SH.

[0024] In any embodiment of the second aspect of this application, the passivating agent comprises a compound with the structure shown in Formula I, R 1 -R 3 -R 2 Structural Formula I

[0025] in,

[0026] R 1 R is a positively charged group. 2 R is an electron-rich group. 3 It is a C2-C8 alkylene group.

[0027] In any embodiment of the second aspect of this application, R 3 It is a C3-C5 alkylene group.

[0028] In any embodiment of the second aspect of this application, the passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, and INH3-(CH2)5-SCH3. Any one or more of the following: INH3-(CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, CH3COONH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH.

[0029] In any embodiment of the second aspect of this application, the concentration of the passivating agent in the passivating agent solution is 0.1 mg / mL to 1 mg / mL.

[0030] In any embodiment of the second aspect of this application, the solvent in the passivating agent solution includes any one or more mixed solvents selected from isopropanol, chlorobenzene, toluene, and anisole.

[0031] In any embodiment of the second aspect of this application, the solvent in the passivating agent solution is selected from a mixture of isopropanol and chlorobenzene.

[0032] In any embodiment of the second aspect of this application, the solvent in the passivating agent solution is selected from a mixed solvent of isopropanol and chlorobenzene in a volume ratio of 1:9 to 9:1.

[0033] In any embodiment of the second aspect of this application, the annealing temperature is 80°C-120°C and the time is 5 min-30 min.

[0034] In any embodiment of the second aspect of this application, the process of preparing the perovskite light-absorbing layer includes:

[0035] A perovskite precursor solution was prepared, comprising an organic source and an inorganic source, wherein the inorganic source included lead halide with an excess of lead halide, and the mass ratio of passivating agent to excess lead halide was 6:1-60:1.

[0036] Perovskite light-absorbing layers are prepared on hole transport layers or electron transport layers using perovskite precursor solutions.

[0037] A third aspect of this application provides a photovoltaic system including a perovskite solar cell provided in any embodiment of the first aspect described above.

[0038] The fourth aspect of this application provides an electrical device, including a perovskite solar cell provided in any embodiment of the first aspect or a photovoltaic system provided in any embodiment of the second aspect.

[0039] The fifth aspect of this application provides a power generation device, including a perovskite solar cell provided in any embodiment of the first aspect or a photovoltaic system provided in any embodiment of the second aspect. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0041] Figure 1 is a schematic block diagram of a perovskite solar cell structure provided in one embodiment of this application.

[0042] Figure 2 is a schematic block diagram of a perovskite solar cell structure provided in another embodiment of this application.

[0043] The accompanying drawings are not drawn to scale.

[0044] Explanation of reference numerals in the attached figures: 1. Transparent conductive electrode; 2. Hole transport layer; 3. Perovskite light-absorbing layer; 4. Passivation layer; 5. Electron transport layer; 6. Back electrode. Detailed Implementation

[0045] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0046] The following detailed description, with appropriate reference to the accompanying drawings, discloses embodiments of the perovskite solar cell and its fabrication method of this application. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of essentially identical structures may be omitted. This is to avoid unnecessarily lengthy descriptions and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0047] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0048] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0049] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0050] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0051] Unless otherwise specified, the terms "comprising" and "including" as used in this application are open-ended. For example, "comprising" and "including" may mean that other components not listed may also be included or contained.

[0052] Unless otherwise specified, the term "or" is inclusive in this application. For example, any of the following conditions satisfies the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0053] Passivating perovskite surface defects with passivating agents can reduce the loss of effective charge carriers caused by nonradiative recombination. However, due to the complex composition of perovskite surface defects, the passivation effect of conventional passivating agents is not ideal. Analysis of the nature of these defects reveals that perovskite surface defects can be divided into positively charged defects and negatively charged defects. Positively charged defects are generally due to Pb... 2+ Negative charge defects are generally caused by undermatched I sites or I vacancies. - or FA + This is due to vacancies. Based on the above findings, the first embodiment of this application provides a perovskite solar cell, as shown in Figure 1 or Figure 2. It includes a first electrode, a perovskite light-absorbing layer 3, a passivation layer 4, and a second electrode. The passivation layer 4 includes a passivating agent, which comprises a positively charged group and an electron-rich group. The positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

[0054] The passivating agent of this application has positively charged groups and electron-rich groups, that is, it is a bifunctional passivating agent. The positively charged groups reduce the carrier recombination centers caused by positively charged defects, and the negatively charged groups reduce the reverse built-in electric field caused by negatively charged defects, thereby effectively improving the open-circuit voltage and fill factor of the perovskite solar cell, and thus improving the photoelectric conversion efficiency of the perovskite solar cell. In addition, the aforementioned electron-rich groups can also adjust the dipole moment of the passivating agent, enhance the field-effect passivation effect, and make the improvement of photoelectric conversion efficiency more significant.

[0055] The aforementioned passivation layer can be applied to any surface of the perovskite light-absorbing layer, and can passivate the surface defects of the perovskite light-absorbing layer.

[0056] The above-mentioned functional groups can be tested using Fourier transform infrared spectroscopy or secondary ion mass spectrometry: remove the second electrode to expose the perovskite light-absorbing layer and passivation layer to obtain the sample to be tested, and analyze the sample using Fourier transform infrared spectroscopy or secondary ion mass spectrometry to obtain the functional group information of the passivating agent.

[0057] To further improve the passivation effect by utilizing the above-mentioned passivating agent, in some embodiments, the positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, R includes C1-C3 alkyl (optionally R is methyl or ethyl), the halogen includes any one of Cl, Br, and I, the pseudohalogen includes -SCN, and the electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH.

[0058] In some embodiments, the positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOCH3, and -SCN, and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH. In some embodiments, the positively charged group is selected from -NH3X, where X is selected from any one of Cl, Br, and I, and the electron-rich group is selected from any one of -CF3, -SCH3, and -SH.

[0059] In some embodiments, the passivating agent comprises a compound with the structure shown in Formula I.

[0060] R 1 -R 3 -R 2 Structural Formula I

[0061] Among them, R 1 R is a positively charged group. 2 R is an electron-rich group. 3 It is a C2-C8 alkylene group, R 3 The alkylene group can be C3-C5. In perovskite materials, the A-site cation is usually a short alkyl chain. The passivating agent with the above structural formula I is more likely to replace the vacancy of the A-site cation than other groups, and maintain the stability of the perovskite structure.

[0062] When compounds with the above structural formula I are used as passivating agents, they have a simple and stable structure and a good passivation effect.

[0063] Considering that branched alkylene groups can weaken the field-effect passivation or chemical passivation effect of the passivating agent, in some embodiments, R 3 It is a C2-C8 straight-chain alkylene group, R 3 It can further be selected as a C3-C5 straight-chain alkylene group. This controls R. 3The impact on passivation effect.

[0064] To save costs, in some embodiments, the passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, and INH3-(CH2)5-SCH3. Any one or more of the following: INH3-(CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, CH3COONH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH.

[0065] Since surface defects in the perovskite light-absorbing layer are largely formed by lead halides on the surface, in some embodiments, in order to solve the surface defect problem more efficiently, the surface of the perovskite light-absorbing layer has lead halides, and the mass ratio of passivator to lead halide is 6:1-60:1.

[0066] Excess lead halide on the surface of a perovskite light-absorbing layer can be determined by XPS characterization of the Pb to I ratio on the surface of the perovskite light-absorbing layer.

[0067] The aforementioned surface refers to the surface of the perovskite light-absorbing layer with a passivation layer, and its thickness is based on the thickness that can be characterized by XPS.

[0068] First electrode and second electrode

[0069] In some embodiments, the electrode materials in the first and second electrodes include one or more of organic conductive materials, inorganic conductive materials, or organic-inorganic mixed conductive materials.

[0070] For example, the organic conductive material includes a conductive polymer, which includes one or more of poly(3,4-ethylenedioxythiophene) (PEDOT), polythiophene, polyacetylene, etc.

[0071] For example, inorganic conductive materials include one or more of transparent conductive oxides, metals and their alloys, carbon derivatives, etc.

[0072] For example, the transparent conductive oxide includes one or more of FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), lanthanide-doped indium oxide, AZO (aluminum-doped zinc oxide), antimony-doped tin oxide, BZO (boron-doped zinc oxide), AZO (aluminum-doped zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), and IWO (tungsten-doped indium oxide).

[0073] For example, the metallic material includes one or more of gold (Au), silver (Ag), copper (Cu), aluminum (Al), nickel (Ni), chromium (Cr), bismuth (Bi), platinum (Pt), magnesium (Mg), molybdenum (Mo), tungsten (W), and their alloys.

[0074] For example, the carbon derivative includes at least one of graphite, graphene, and carbon nanotubes.

[0075] In some embodiments, one of the first electrode and the second electrode is a transparent conductive electrode 1 and the other is a back electrode 6.

[0076] Before use, clean the transparent conductive electrode with a cleaning agent, deionized water, and ethanol.

[0077] Perovskite light-absorbing layer

[0078] The perovskite light-absorbing layer has the chemical formula ABX'3, where A is a monovalent cation with a large radius, including organic cations, inorganic cations, or mixed organic-inorganic cations, including but not limited to the following materials: Li + Na + K + Cs + 、Rb + CH3NH + (Methylamine ion), HC(NH2)2 + (formamidinium ion), etc.; B is a divalent metal cation with a small radius, including but not limited to the following materials: divalent metal cations such as Pb. 2+ Be 2+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Zn 2+ 、Ge 2+ Fe 2+ Co 2+ Ni 2+ Sn 2+etc.; X' is a monovalent anion, including but not limited to the following materials: Cl - ,Br - I - SCN - CNO - OCN - OSCN - SH - OH - CP - CN - SeCN - N3 - NO2 - The perovskite layer has a band gap of 1.20-2.30 eV and a thickness of 400-1000 nm.

[0079] In some embodiments, the first electrode, the perovskite light-absorbing layer, the passivation layer, and the second electrode are stacked.

[0080] In some embodiments, the perovskite solar cell further includes a first charge transport layer and a second charge transport layer. The first charge transport layer is disposed between the first electrode and the perovskite light-absorbing layer, and the second charge transport layer is disposed between the passivation layer and the second electrode. One of the first charge transport layer and the second charge transport layer is a hole transport layer 2 and the other is an electron transport layer 5.

[0081] Hole transport layer

[0082] Hole transport layers are used to collect and extract holes from perovskite layers.

[0083] In some embodiments, the hole transport layer comprises one or more of nickel oxide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and polyethylenedioxythiophene-polystyrene sulfonate (PEDOT:PSS). However, this application is not limited thereto. Other hole transport layer compositions suitable for perovskite solar cells are also covered within the scope of this application.

[0084] Electron transport layer

[0085] In some embodiments, the electron transport layer material includes at least one of the following materials and their derivatives or doped and passivated materials: methyl [6,6]-phenyl C61 butyrate (PC61BM), methyl [6,6]-phenyl C71 butyrate (PC71BM), fullerenes and their derivatives, and tin dioxide (SnO2), zinc oxide (ZnO), etc.

[0086] The perovskite solar cell in this application can be either a conventional structure or an inverted structure. In some embodiments, the first electrode is a transparent conductive electrode, the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer, and the second electrode is a back electrode. In some embodiments, a barrier layer may also be disposed between the electron transport layer and the back electrode. The barrier layer includes indium tungsten oxide (IWO), indium tin oxide (ITO), copper bath (BCP), zirconium acetylacetonate, etc.

[0087] In some embodiments, the first electrode is a transparent conductive electrode, the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer, and the second electrode is a back electrode.

[0088] As shown in Figure 1, the perovskite solar cell of this application has a formal structure, including a transparent conductive electrode 1, a hole transport layer 2, a perovskite light-absorbing layer 3, a passivation layer 4, an electron transport layer 5, and a back electrode 6 stacked sequentially.

[0089] As shown in Figure 2, the perovskite solar cell of this application has an inverted structure, including a transparent conductive electrode 1, an electron transport layer 5, a perovskite light-absorbing layer 3, a passivation layer 4, a hole transport layer 2, and a back electrode 6 stacked sequentially.

[0090] [Preparation methods for perovskite solar cells]

[0091] The second embodiment of this application provides a method for fabricating a perovskite solar cell. The method includes a process for fabricating a passivation layer on a perovskite light-absorbing layer. The process for fabricating the passivation layer includes:

[0092] A passivating agent solution is placed on a perovskite light-absorbing layer and annealed to obtain a passivation layer. The passivating agent includes a positively charged group and an electron-rich group. The positively charged group is selected from -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

[0093] The passivating agent used in this application to prepare the passivation layer has positively charged groups and electron-rich groups, i.e., it is a bifunctional passivating agent. The positively charged groups reduce the carrier recombination centers caused by positively charged defects, and the negatively charged groups reduce the reverse built-in electric field caused by negatively charged defects, thereby effectively improving the open-circuit voltage and fill factor of the perovskite solar cell, and thus improving the photoelectric conversion efficiency of the perovskite solar cell. In addition, the aforementioned electron-rich groups can also adjust the dipole moment of the passivating agent, enhancing the field-effect passivation effect and making the improvement of photoelectric conversion efficiency more significant.

[0094] The process of applying a passivating agent to the surface of the perovskite light-absorbing layer may include:

[0095] The passivating agent solution is dropped onto the perovskite light-absorbing layer, and then spread onto the surface of the perovskite light-absorbing layer by spin coating. Spin coating improves processing efficiency. The spin coating speed and time used in the above process can be based on conventional techniques, such as a spin coating speed of 3000 rpm-5000 rpm, or continuous spin coating for 20-40 seconds.

[0096] To further improve the passivation effect using the aforementioned passivating agent, in some embodiments, the positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR; R includes a C1-C3 alkyl group (optionally R is methyl or ethyl); the halogen includes any one of Cl, Br, and I; the pseudohalogen includes -SCN; and the electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH. In some embodiments, the positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOCH3, and SCN; and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH. In some embodiments, the positively charged group is selected from -NH3X, where X is selected from any one of Cl, Br, and I; and the electron-rich group is selected from any one of -CF3, -SCH3, and -SH.

[0097] In some embodiments, the passivating agent comprises a compound with the structure shown in Formula I.

[0098] R 1 -R 3 -R 2 Structural Formula I

[0099] Among them, R 1 R is a positively charged group. 2 R is an electron-rich group. 3 It is a C2-C8 alkylene group, R 3 The alkylene group can be C3-C5. In perovskite materials, the A-site cation is usually a short alkyl chain. The passivating agent with the above structural formula I is more likely to replace the vacancy of the A-site cation than other groups, and maintain the stability of the perovskite structure.

[0100] When compounds with the above structural formula I are used as passivating agents, they have a simple and stable structure and a good passivation effect.

[0101] Considering that branched alkylene groups can weaken the field-effect passivation or chemical passivation effect of the passivating agent, in some embodiments, R 3 It is a C2-C8 straight-chain alkylene group, R 3 It can further be selected as a C3-C5 straight-chain alkylene group. This controls R.3 The impact on passivation effect.

[0102] To save costs, in some embodiments, the passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, and INH3-(CH2)5-SCH3. Any one or more of the following: INH3-(CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, CH3COONH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH.

[0103] The amount of passivating agent used in this application can be referenced from the amount of conventional passivating agents. In some embodiments, to avoid increased construction difficulty caused by excessive passivating agent concentration, the concentration of passivating agent in the passivating agent solution is 0.1 mg / mL to 1 mg / mL. A concentration within the above range is beneficial for uniform application of the passivating agent.

[0104] In order to improve the stability of the passivating agent solution and the uniformity of the passivating agent dispersion therein, in some embodiments, the solvent in the passivating agent solution includes any one or more mixed solvents selected from isopropanol, chlorobenzene, toluene, and anisole.

[0105] In some embodiments, the solvent in the passivating agent solution is selected from a mixture of isopropanol and chlorobenzene. Using a mixture of chlorobenzene and isopropanol as a solvent can achieve sufficient dispersion of the passivating agent, and the dilution effect of chlorobenzene on isopropanol can effectively alleviate the surface damage of isopropanol to the perovskite light-absorbing layer.

[0106] In order to fully utilize the role of each component in the above solvent, in some embodiments, the solvent in the passivating agent solution is selected from a mixed solvent of isopropanol and chlorobenzene with a volume ratio of 1:9 to 9:1.

[0107] In some embodiments, the annealing temperature is 80℃-120℃, and the time is 5min-30min. By controlling the temperature and time as described above, the passivating agent and perovskite can be better bonded together, and the decomposition of perovskite can be effectively controlled.

[0108] The process for preparing the perovskite light-absorbing layer described above can refer to conventional methods. In some embodiments, the process includes: preparing a perovskite precursor solution, which includes an organic source and an inorganic source, wherein the organic source includes lead halide and lead halide is added in excess, and the mass ratio of the passivating agent to the excess lead halide is 6:1-60:1; and preparing the perovskite light-absorbing layer on the electron transport layer using the perovskite solution. By controlling the above ratio, the surface defects caused by excess lead halide can be better addressed using the passivating agent.

[0109] The process of preparing a hole transport layer on a transparent conductive electrode can also refer to conventional techniques. For example, the transparent conductive electrode is treated with ultraviolet ozone, then nickel oxide is sputtered by magnetron sputtering or organic hole transport material is spin-coated, and then annealed.

[0110] The process of preparing the electron transport layer can also refer to conventional techniques. For example, the electron transport layer can be prepared by vapor deposition.

[0111] The process of preparing the back electrode can also refer to conventional techniques. For example, the back electrode can be prepared by vapor deposition.

[0112] [Example]

[0113] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0114] The passivating agents used in the following examples are as follows.

[0115] The synthesis method of 3-trifluoromethyl-propylamine hydroiodate (INH3-(CH2)3-CF3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-trifluoromethyl-propylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-trifluoromethyl-propylamine hydroiodate.

[0116] The synthesis of 3-methoxy-propylamine hydroiodate (INH3-(CH2)3-OCH3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-methoxy-propylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-methoxy-propylamine hydroiodate.

[0117] The synthesis method of 3-methylthiopropylamine hydroiodate (INH3-(CH2)3-SCH3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-methylthiopropylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-methylthiopropylamine hydroiodate.

[0118] The synthesis method of 3-thiocyano-propylamine hydroiodate (INH3-(CH2)3-SCN) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-thiocyano-propylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-thiocyano-propylamine hydroiodate.

[0119] The synthesis method of 3-mercaptopropylamine hydroiodate (INH3-(CH2)3-SH) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-mercaptopropylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-mercaptopropylamine hydroiodate.

[0120] The synthesis method of methylthiopentylamine hydroiodate (INH3-(CH2)5-SCH3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and methylthiopentylamine is slowly added at a molar ratio of 1:1. After stirring in the ice-water bath for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding methylthiopentylamine hydroiodate.

[0121] The synthesis method of 3-methylthiopropylamine acetate (AcNH3-(CH2)3-SCH3) is as follows: Acetic acid is stirred in an ice-water bath, and 3-methylthiopropylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-methylthiopropylamine acetate.

[0122] The synthesis method of 3-trifluoromethyl-propylamine acetate (AcNH3-(CH2)3-CF3) is as follows: Acetic acid is stirred in an ice-water bath, and 3-trifluoromethyl-propylamine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-trifluoromethyl-propylamine acetate.

[0123] The synthesis method of 3-(methylthio)but-1-amine hydroiodate (INH3CH2CH2CH(CH3)SCH3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 3-(methylthio)but-1-amine is slowly added at a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 3-(methylthio)but-1-amine hydroiodate.

[0124] The synthesis method of 2-methyl-4-(methylthio)but-2-amine hydroiodate (INH3(CH3)2CCH2CH2SCH3) is as follows: Hydroiodic acid is stirred in an ice-water bath, and 2-methyl-4-(methylthio)but-2-amine is slowly added in a molar ratio of 1:1. After stirring in ice water for 2 hours, the mixture is rotary evaporated at 50°C until a white solid is obtained, which is then washed several times with diethyl ether. Finally, the product is dried in a vacuum drying oven to obtain the corresponding 2-methyl-4-(methylthio)but-2-amine hydroiodate.

[0125] Example 1

[0126] The perovskite solar cell in Example 1 has the following structure in sequence: FTO conductive glass electrode, hole transport layer, perovskite light-absorbing layer, passivation layer, electron transport layer, blocking layer, and metal electrode. The fabrication method is as follows:

[0127] Step 1), Prepare an FTO conductive glass electrode with dimensions of 2.0 × 2.0 cm. 2The FTO glass was laser-etched to remove 0.35 cm of FTO from each end, exposing the glass substrate. The etched FTO conductive glass was then ultrasonically cleaned several times with water, acetone, and isopropanol, and then dried with nitrogen for later use.

[0128] Step 2), Preparation of hole transport layer: The FTO conductive glass electrode is subjected to ultraviolet ozone treatment, and then a nickel oxide with a thickness of about 25 nm is sputtered by magnetron sputtering. The electrode is then annealed at 300°C for 60 min to obtain the hole transport layer.

[0129] Step 3), Preparation of the perovskite light-absorbing layer: A one-step method was used to prepare the perovskite light-absorbing layer. A perovskite precursor solution was spin-coated onto the prepared hole transport layer at 4000 rpm for 30 seconds. Approximately 10 seconds into the spin-coating, 500 μL of chlorobenzene was added dropwise. After spin-coating, a product containing the perovskite precursor solution was obtained. The perovskite precursor solution contained 1.2 mol / L formamidinium hydroiodate (FAI) and 1.32 mol / L PbI₂, with a solvent volume ratio of DMF:DMSO = 3:1. The product was then placed on a hot plate and annealed at 100-120℃ for 10 minutes to obtain a 500 nm thick FAPbI₃ perovskite light-absorbing layer.

[0130] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-CF3 (3-trifluoromethyl-propylamine hydroiodate) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a passivation layer with a thickness of about 1 nm.

[0131] Step 5), Preparation of the electron transport layer: Place the product with the passivation layer prepared above into a vapor deposition apparatus, and wait for the vapor deposition vacuum degree to reach 5×10 -4 A 30 nm electron transport layer C60 was deposited at a rate of 0.05 A / s below Pa.

[0132] Step 6), Preparation of the barrier layer: A 10 nm barrier layer BCP is deposited on the electron transport layer C60 using a vapor deposition apparatus at a rate of 0.1 A / s.

[0133] Step 7), Preparation of the metal electrode: Place the product with the barrier layer into the vapor deposition apparatus, and wait for the vapor deposition vacuum to reach 5 × 10⁻⁶. - 4 Below Pa, an 80 nm metal back electrode Ag was deposited by vapor deposition at a rate of 0.1 A / s.

[0134] Example 2

[0135] Except for step 4), the remaining steps are the same as in Example 1.

[0136] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-OCH3 (3-methoxy-propylamine hydroiodate) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0137] Example 3

[0138] Except for step 4), the remaining steps are the same as in Example 1.

[0139] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-SCH3 (3-methylthio-propylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0140] Example 4

[0141] Except for step 4), the remaining steps are the same as in Example 1.

[0142] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-SCN (3-thiocyano-propylamine hydroiodate) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0143] Example 5

[0144] Except for step 4), the remaining steps are the same as in Example 1.

[0145] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-SH (3-mercapto-propylamine hydroiodate) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0146] Example 6

[0147] Except for step 4), the remaining steps are the same as in Example 1.

[0148] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)5-SCH3 (methylthiopentylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) is spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0149] Example 7

[0150] Except for step 4), the remaining steps are the same as in Example 1.

[0151] Step 4), preparation of passivation layer: 0.8 mg / mL AcNH3-(CH2)3-SCH3 (methylthiopropylamine acetic acid) isopropanol / chlorobenzene solution (volume ratio 1:1) is spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0152] Example 8

[0153] Except for step 4), the remaining steps are the same as in Example 1.

[0154] Step 4), preparation of passivation layer: 0.8 mg / mL AcNH3-(CH2)3-CF3 (3-trifluoromethylpropylamine acetic acid) isopropanol / chlorobenzene solution (volume ratio 1:1) is spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0155] Example 9

[0156] Except for step 4), the remaining steps are the same as in Example 3.

[0157] Step 4), preparation of the passivation layer: 0.8 mg / mL INH3CH2CH2CH(CH3)SCH3 (3-(methylthio)but-1-amine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0158] Example 10

[0159] Except for step 4), the remaining steps are the same as in Example 3.

[0160] Step 4), preparation of the passivation layer: 0.8 mg / mL INH3(CH3)2CCH2CH2SCH3 (2-methyl-4-(methylthio)but-2-amine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0161] Comparative Example 1

[0162] Except for step 4), the remaining steps are the same as in Example 1.

[0163] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-CH3 (propylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0164] Comparative Example 2

[0165] Except for step 4), the remaining steps are the same as in Example 1.

[0166] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-(CH2)3-NH2 (propanediamine iodine) isopropanol / chlorobenzene solution (volume ratio 1:1) is spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0167] Comparative Example 3

[0168] Step 4 is omitted; the remaining steps are the same as in Example 1.

[0169] Performance testing

[0170] 1. Photovoltaic conversion efficiency of perovskite solar cells

[0171] Using Keithley 2400SMU, AM 1.5G solar irradiation at 100mW / cm 2 Under a specific light source, the performance of the perovskite solar cells in the embodiments and comparative examples was tested, and the photoelectric conversion efficiency was calculated as follows:

[0172] PCE = Pout / Pin = Voc × Jsc × [(Vmpp × Jmpp) / (Voc × Jsc)] / Pin = Voc × Jsc × FF / Pin Where Pout, Pin, Voc, Jsc, Vmpp, Jmpp, and FF are the battery's operating output power, incident light power, open-circuit voltage, short-circuit current density, maximum power point voltage, maximum power point current, and fill factor, respectively. Voc, Jsc, Vmpp, Jmpp, and FF are measured using a digital multimeter.

[0173] The test results and calculation results are recorded in Table 1.

[0174] Table 1

[0175] As can be seen from the comparison of Examples 1 to 10 and Comparative Examples 1 to 3, the bifunctional passivating agent used in this application has the dual functions of chemical passivation and field-effect passivation. It can passivate the positive and negative defects on the perovskite surface at the same time, reduce the recombination degree of charge carriers, and significantly improve the Voc and FF of the device, thereby improving the PCE of the device.

[0176] Furthermore, a comparison of Examples 3, 9, and 10 shows that the increase in branched groups weakens the passivation effect, thus affecting the degree of PCE improvement. Specifically, when the branched groups are close to electron-rich groups, the significant decrease in open-circuit voltage in Example 9 compared to Example 3 indicates that branching weakens the chemical passivation effect, thereby affecting the degree of PCE improvement. When the branched groups are close to positively charged groups, both the short-circuit current and open-circuit voltage in Example 10 compared to Example 3 show a significant decrease, indicating that branching weakens the field-effect passivation effect.

[0177] Examples 11 and 12 adjust the concentration of the passivating agent solution to adjust the mass ratio of the passivating agent to the excess lead iodide, as follows.

[0178] Example 11

[0179] Except for step 4), the remaining steps are the same as in Example 1.

[0180] Step 4), preparation of passivation layer: 0.1 mg / mL INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodate) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0181] Example 12

[0182] Except for step 4), the remaining steps are the same as in Example 1.

[0183] Step 4), preparation of the passivation layer: A 1 mg / mL solution of INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodate) in isopropanol / chlorobenzene (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s. The layer was then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of approximately 1 nm. The test results are recorded in Table 2.

[0184] Table 2

[0185] As can be seen from the data in Table 2, when the amount of passivating agent increases, the current of the device decreases slightly, which limits the improvement of the device's photoelectric conversion efficiency; when the amount of passivating agent is small, the improvement of the open-circuit voltage is small, the passivation effect is not significant, which affects the degree of improvement of the device's photoelectric conversion efficiency.

[0186] The following adjustments to the process conditions were made to examine their impact on the passivation results.

[0187] Example 13

[0188] Except for step 4), the remaining steps are the same as in Example 1.

[0189] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 120 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0190] Example 14

[0191] Except for step 4), the remaining steps are the same as in Example 1.

[0192] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 1:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 80 °C for 30 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0193] Example 15

[0194] Except for step 4), the remaining steps are the same as in Example 1.

[0195] Step 4), preparation of passivation layer: 0.8 mg / mL INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodide) isopropanol / chlorobenzene solution (volume ratio 9:1) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of about 1 nm.

[0196] Example 16

[0197] Except for step 4), the remaining steps are the same as in Example 1.

[0198] Step 4), preparation of the passivation layer: A 0.8 mg / mL isopropanol / chlorobenzene solution (volume ratio 1:9) of INH3-[CH2]3-CF3 (3-trifluoromethyl-propylamine hydroiodate) was spin-coated onto the perovskite light-absorbing layer at 4500 rpm for 30 s, and then annealed at 100 °C for 5 min to obtain a bifunctional passivation layer with a thickness of approximately 1 nm. The test results of the above embodiments are recorded in Table 3.

[0199] Table 3

[0200] A comparison of the data from Examples 1, 13, and 14 reveals that variations in annealing conditions during passivation layer formation can also affect the device's photoelectric conversion efficiency. This may be because the annealing temperature and time can affect the degree of bonding between the passivating agent and the perovskite, thus impacting the passivation effect.

[0201] A comparison of the data from Examples 1, 15, and 16 reveals that as the proportion of isopropanol in the passivator solution increases, the photoelectric conversion efficiency of the device first increases and then decreases. This may be because although isopropanol helps disperse the passivator, excessive isopropanol can also cause some surface damage to the perovskite light-absorbing layer.

[0202] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A perovskite solar cell, comprising a first electrode, a perovskite light-absorbing layer, a passivation layer, and a second electrode, wherein, The passivation layer includes a passivating agent, which includes a positively charged group and an electron-rich group. The positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

2. The perovskite solar cell according to claim 1, wherein, The positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes a C1-C3 alkyl group. The halogen includes any one of Cl, Br, and I, and the pseudohalogen includes -SCN. The electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH.

3. The perovskite solar cell according to claim 1 or 2, wherein, The positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOCH3, and -SCN, and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH.

4. The perovskite solar cell according to claim 1, wherein, The positively charged group includes -NH3X, where X includes any one of Cl, Br, and I, and the electron-rich group includes any one of -CF3, -SCH3, and -SH.

5. The perovskite solar cell according to any one of claims 1 to 4, wherein, The passivating agent includes compounds with the structure shown in Formula I. R 1 -R 3 -R 2 Structural Formula I Among them, R 1 R is the positively charged group. 2 R is the electron-rich group. 3 It is a C2-C8 alkylene group.

6. The perovskite solar cell according to claim 5, wherein, The R 3 It is a C3-C5 alkylene group.

7. The perovskite solar cell according to claim 5 or 6, wherein, The passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, INH3-(CH2)5-SCH3, INH3- Any one or more of (CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, HOOCNH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH.

8. The perovskite solar cell according to any one of claims 1 to 7, wherein, The surface of the perovskite light-absorbing layer has lead halide, and the mass ratio of the passivating agent to the lead halide is 6:1-60:

1.

9. The perovskite solar cell according to any one of claims 1 to 8, wherein, The perovskite solar cell further includes a first charge transport layer and a second charge transport layer. The first charge transport layer is disposed between the first electrode and the perovskite light-absorbing layer, and the second charge transport layer is disposed between the passivation layer and the second electrode. One of the first charge transport layer and the second charge transport layer is a hole transport layer and the other is an electron transport layer.

10. The perovskite solar cell according to claim 9, wherein, The first electrode is a transparent conductive electrode, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer.

11. A method for fabricating a perovskite solar cell, the method comprising fabricating a perovskite light-absorbing layer, a passivation layer, and a second electrode on a first electrode, wherein, The step of preparing the passivation layer includes: A passivating agent solution is placed on a perovskite light-absorbing layer and annealed to obtain the passivation layer. The passivating agent includes a positively charged group and an electron-rich group. The positively charged group is selected from -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes any one of C1-C6 alkyl groups. The electron-rich group includes any one of C1-C6 haloalkyl, C1-C6 alkoxy, C1-C6 alkylthio, -SCN, and -SH.

12. The preparation method according to claim 11, wherein, The positively charged group includes -NH3X, where X includes any one of halogen, pseudohalogen, and -COOR, and R includes a C1-C3 alkyl group. The halogen includes any one of Cl, Br, and I, and the pseudohalogen includes -SCN. The electron-rich group includes any one of C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 alkylthio, -SCN, and -SH.

13. The preparation method according to claim 11 or 12, wherein, The positively charged group includes -NH3X, where X includes any one of Cl, Br, I, -COOCH3, and -SCN, and the electron-rich group includes any one of -CF3, -OCH3, -SCH3, -SCN, and -SH.

14. The preparation method according to any one of claims 11 to 13, wherein, The positively charged group is selected from -NH3X, where X is selected from any one of Cl, Br, and I, and the electron-rich group is selected from any one of -CF3, -SCH3, and -SH.

15. The preparation method according to any one of claims 11 to 14, wherein, The passivating agent includes compounds with the structure shown in Formula I. R 1 -R 3 -R 2 Structural Formula I Among them, R 1 R is the positively charged group. 2 R is the electron-rich group. 3 It is a C2-C8 alkylene group.

16. The preparation method according to claim 15, wherein, R 3 It is a C3-C5 alkylene group.

17. The preparation method according to claim 15 or 16, wherein, The passivating agent is selected from INH3-(CH2)3-CF3, INH3-(CH2)3-OCH3, INH3-(CH2)3-SCH3, INH3-(CH2)3-SCN, INH3-(CH2)3-SH, INH3-(CH2)4-CF3, INH3-(CH2)4-OCH3, INH3-(CH2)4-SCH3, INH3-(CH2)4-SCN, INH3-(CH2)4-SH, INH3-(CH2)5-CF3, INH3-(CH2)5-OCH3, INH3-(CH2)5-SCH3, INH3-( CH2)5-SCN, INH3-(CH2)5-SH, ClNH3-(CH2)3-CF3, ClNH3-(CH2)3-OCH3, ClNH3-(CH2)3-SCH3, ClNH3-(CH2)3-SCN, ClNH3-(CH2)3-SH, CH3COONH3-(CH2)3-CF3, CH3COONH3-(CH2)3-OCH3, CH3COONH3-(CH2)3-SCH3, CH3COONH3-(CH2)3-SCN, and CH3COONH3-(CH2)3-SH are any one or more of these.

18. The preparation method according to any one of claims 11 to 17, wherein, The concentration of the passivating agent in the passivating agent solution is 0.1 mg / mL to 1 mg / mL.

19. The preparation method according to any one of claims 11 to 18, wherein, The solvent in the passivating agent solution includes any one or more mixed solvents selected from isopropanol, chlorobenzene, toluene, and anisole.

20. The preparation method according to claim 19, wherein, The solvent in the passivating agent solution is selected from a mixture of isopropanol and chlorobenzene.

21. The preparation method according to claim 20, wherein, The solvent in the passivating agent solution is selected from a mixture of isopropanol and chlorobenzene in a volume ratio of 1:9 to 9:

1.

22. The preparation method according to any one of claims 11 to 21, wherein, The annealing temperature is 80℃-120℃, and the time is 5min-30min.

23. The preparation method according to any one of claims 11 to 22, wherein, The process for preparing the perovskite light-absorbing layer includes: A perovskite precursor solution is prepared, wherein the perovskite precursor solution includes an organic source and an inorganic source, wherein the inorganic source includes lead halide and the lead halide is added in excess, and the mass ratio of the passivating agent to the excess lead halide is 6:1-60:

1. A perovskite light-absorbing layer is prepared on a hole transport layer or an electron transport layer using the perovskite precursor solution.

24. A photovoltaic system comprising a perovskite solar cell according to any one of claims 1 to 10.

25. An electrical device comprising a perovskite solar cell according to any one of claims 1 to 10 or a photovoltaic system according to claim 14.

26. A power generation device comprising a perovskite solar cell according to any one of claims 1 to 10 or a photovoltaic system according to claim 14.

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