Perovskite solar cell and preparation method therefor, photovoltaic module, system, and electric device

Abstract

A perovskite solar cell and a preparation method therefor, a photovoltaic module, a system, and an electric device. The perovskite solar cell comprises a transparent electrode layer, and a perovskite layer, an electron transport layer, and a metal electrode which are sequentially arranged on the transparent electrode layer; the electron transport layer comprises an organic electron transport material, a first additive, and a second additive; the first additive comprises one or more of poly(methyl methacrylate), a methacrylic acid-methyl methacrylate copolymer, a 4-vinylpyridine-styrene copolymer, polyacrylonitrile, and poly(4-vinylpyridine); and the second additive comprises one or more of a compound of formula I and a compound of formula II. The perovskite solar cell has high photoelectric conversion efficiency and good stability.

Description

Perovskite solar cell and preparation method thereof, photovoltaic module, system and electrical device

[0001] Cross-references

[0002] This application claims priority to Chinese Patent Application No. 202310855619.X, filed on July 12, 2023, entitled “Perovskite Solar Cells and Preparation Methods, Photovoltaic Components, Systems and Electrical Devices Thereof,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present application relates to the technical field of solar cells, and in particular to a perovskite solar cell, a photovoltaic module, a system and an electrical device. Background Art

[0004] With the rapid development of new energy, solar cells have been widely used in industry, commerce, agriculture, and communications. Perovskite solar cells (PSCs) are devices that convert solar energy into electrical energy using the photoelectric conversion mechanism of perovskite crystal materials. They are currently the third generation of solar cells and have been extensively researched in recent years due to their high photoelectric conversion efficiency, simple manufacturing process, and low production cost.

[0005] With the maturation of manufacturing processes and the continuous reduction in prices for organic electron transport layer materials such as fullerene derivatives, naphthalene diimide, and perylene diimide, these materials are becoming increasingly suitable for industrial mass production. These materials can improve device hysteresis and, to a certain extent, enhance the device's photoelectric conversion efficiency. However, the photoelectric conversion efficiency of current perovskite solar cells using these materials still needs to be further improved, and their cell stability is relatively poor.

[0006] Therefore, how to improve the photoelectric conversion efficiency and stability of perovskite solar cells using organic materials as electron transport layers is one of the key issues that need to be urgently addressed in this field.

[0007] Summary of the Invention

[0008] The present application is made in view of the above-mentioned problems, and one of its purposes is to provide a perovskite solar cell with higher photoelectric conversion efficiency and better stability.

[0009] In order to achieve the above-mentioned object, the first aspect of the present application provides a perovskite solar cell, comprising a transparent electrode layer and a perovskite layer, an electron transport layer and a metal electrode sequentially arranged on the transparent electrode layer;

[0010] The electron transport layer includes an organic electron transport material, a first additive, and a second additive;

[0011] The first additive includes one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly-4-vinylpyridine;

[0012] The second additive includes one or more of the following compounds of formula I and formula II:

[0013] Wherein, R1, R2, R3, R5 and R6 are independently selected from C1~C4 alkyl groups; n1 and n2 are independently integers of 1~6; m1 and m2 are independently integers of 1~4; R4 and R7 are independently C1~C5 alkyl groups, C1~C5 alkoxy groups, C1~C5 alkylthio groups, aryl groups, halogen groups, carboxyl groups, cyano groups or do not exist; X is one or more of Cl, Br, I, BF4, PF6 and TFSI (bistrifluoromethanesulfonyl imide); Y1 and Y2 are independently selected from any one of CH2, NH, O and S or do not exist.

[0014] The perovskite solar cell of the present application adds a specific organic polymer as a first additive in the electron transport layer using an organic electron transport material, and adds a specific quaternary ammonium salt and / or tertiary amine molecule as a second additive. The introduction of the organic polymer first additive can improve the dispersibility of the organic electron transport material in the solution forming the electron transport layer, improve the film uniformity of the electron transport layer, and reduce the entry channel of water molecules in the electron transport layer; the quaternary ammonium salt second additive can significantly improve the film conductivity of the electron transport layer; the tertiary amine molecule second additive can improve the binding force between the molecules of the organic electron transport material; the above-mentioned quaternary ammonium salt and tertiary amine molecules can form a passivation layer with the perovskite interface during the molecular crystallization process of the electron transport layer to reduce the diffusion of perovskite ions. Through the combined action of the above-mentioned specific first additive and second additive, the photoelectric conversion efficiency and stability of the perovskite solar cell can be improved.

[0015] In any embodiment, based on the total mass of the electron transport layer, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%. This can further improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0016] In any embodiment, the second additive includes the compound of formula I and the compound of formula II, and the mass ratio of the compound of formula I to the compound of formula II is (0.5-2): 1. In this way, the photoelectric conversion efficiency and stability of the perovskite solar cell can be further improved.

[0017] In any embodiment, the compound of formula I comprises one or more of tetrabutylammonium tetrafluoroborate, hexamethonium iodide, and dodecyltrimethylammonium bromide.

[0018] In any embodiment, the compound of formula II includes one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

[0019] In any embodiment, the thickness of the electron transport layer is 25 nm to 45 nm.

[0020] In any embodiment, the organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, and perylene diimide and its derivatives.

[0021] A second aspect of the present application provides a method for preparing a perovskite solar cell, comprising the following steps:

[0022] providing a transparent electrode layer; and

[0023] forming a perovskite layer, an electron transport layer and a metal electrode in sequence on the transparent electrode layer;

[0024] The solution for forming the electron transport layer includes a solvent and a solute dispersed in the solvent, and the solute includes an organic electron transport material, a first additive, and a second additive.

[0025] By adding specific first additives and second additives to the solution of the electron transport layer, the photoelectric conversion efficiency and stability of perovskite solar cells can be improved.

[0026] In any embodiment, the solvent includes a first organic solvent and a second organic solvent, the boiling point of the first organic solvent is 38° C. to 90° C., and the boiling point of the second organic solvent is 110° C. to 210° C. In this way, the first organic solvent is a low-boiling-point solvent and the second organic solvent is a high-boiling-point solvent. Using a mixed solvent of the first organic solvent and the second organic solvent, the organic electron transport material, the first additive and the second additive are dispersed in the mixed solvent system. This can optimize the crystallization sequence and uniformity of the organic electron transport material molecules and the first additive and the second additive, guide the molecular orientation, enhance the film quality and conductivity of the electron transport layer, and improve the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0027] In any embodiment, the first organic solvent includes one or more of chloroform, dichloromethane, and tetrahydrofuran.

[0028] In any embodiment, the second organic solvent includes one or more of chlorobenzene, o-dichlorobenzene, toluene, o-xylene, anisole, 2-methylanisole, 2-chlorophenol, and 1,2,3,4-tetralin.

[0029] In any embodiment, based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%.

[0030] In any embodiment, based on the total mass of the solution, the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

[0031] In any embodiment, based on the total mass of the solute, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

[0032] The third aspect of the present application provides a photovoltaic assembly, comprising the perovskite solar cell of the first aspect of the present application.

[0033] A fourth aspect of the present application provides a photovoltaic system, comprising the photovoltaic assembly of the third aspect of the present application.

[0034] The fifth aspect of the present application provides an electrical device comprising at least one of the perovskite solar cell of the first aspect of the present application and the photovoltaic module of the third aspect of the present application.

[0035] The perovskite solar cell of the present application can effectively improve the photoelectric conversion efficiency and stability of the perovskite solar cell using organic electron transport materials as the electron transport layer by adding a specific organic polymer as the first additive and adding a specific quaternary ammonium salt and / or tertiary amine molecule as the second additive in the electron transport layer using organic electron transport materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the drawings without inventive work. In the drawings:

[0037] FIG1 is a schematic structural diagram of a perovskite solar cell according to an embodiment of the present application;

[0038] FIG2 is a schematic structural diagram of an electrical device according to an embodiment of the present application.

[0039] Reference numerals:

[0040] 1. Perovskite solar cell; 2. Power-consuming device; 11. Transparent electrode layer; 12. Hole transport layer; 13. Perovskite layer; 14. Electron transport layer; 15. Metal electrode. DETAILED DESCRIPTION

[0041] Below, some embodiments of the perovskite precursor solution, perovskite film, perovskite solar cell and electrical device of the present application are disclosed in detail with appropriate reference to the accompanying drawings. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0042] The "ranges" disclosed herein are defined in terms of lower and upper limits, where a given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. Ranges defined in this manner can be inclusive or exclusive of the end values ​​and can be combined arbitrarily, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a particular parameter, it is understood that ranges of 60 to 110 and 80 to 120 are also contemplated. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise indicated, the numerical range "a to b" is a shorthand representation of any combination of real numbers between a and b, where a and b are both real numbers. For example, a numerical range of "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is merely an abbreviation for a combination of these values. Furthermore, stating that a parameter is an integer ≥ 2 is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, and so on. For example, stating that a parameter is an integer selected from "2-10" is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0043] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0044] Unless otherwise specified, all steps of the present 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 may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0045] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0046] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B." Furthermore, the condition "A or B" is satisfied by any of the following conditions: 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).

[0047] In this application, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0048] In this application, "a plurality of" or "a plurality of" refers to a number greater than or equal to 2 unless otherwise specified. For example, "one or more" means one or more than or equal to two.

[0049] As used herein, "combination thereof", "any combination thereof", "any combination thereof" and the like include all suitable combinations of any two or more of the listed items.

[0050] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc. shall be based on the technical solution that can implement the present application.

[0051] Herein, the terms "preferred," "better," "more preferred," and "suitable" are used solely to describe preferred implementations or examples and should not be construed as limiting the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, each "preferred" term is considered independent unless otherwise specified and there are no contradictions or mutual constraints.

[0052] In this application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be understood as limiting the scope of protection of this application.

[0053] In this application, the terms "first," "second," "third," "fourth," etc. in "the first aspect," "the second aspect," "the third aspect," "the fourth aspect," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or quantity, nor should they be understood as implicitly indicating the importance or quantity of the indicated technical features. Furthermore, "first," "second," "third," "fourth," etc. serve only as non-exhaustive enumeration and description, and should be understood not to constitute a closed-ended limitation on quantity.

[0054] In this application, the term "room temperature" generally refers to 4°C to 35°C, and may refer to 20°C ± 5°C. In some embodiments of this application, room temperature refers to 20°C to 30°C.

[0055] In this application, when referring to a data range, if the unit is only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3h~5h or 3h~5h both mean that the units of the left endpoint "3" and the right endpoint "5" are both hours.

[0056] The weights of the relevant components mentioned in the examples of this application may not only refer to the content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Furthermore, the weights mentioned in the examples of this application may be mass units known in the chemical industry, such as μg, mg, g, and kg.

[0057] As used herein, unless otherwise specified, "alkyl" refers to a monovalent residue formed by the loss of one hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, a secondary carbon atom, a tertiary carbon atom, a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C 1～9"Alkyl" refers to an alkyl group containing 1 to 9 carbon atoms, which can be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl or C9 alkyl at each occurrence. Suitable examples include, but are not limited to, methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), 2-methyl-1-propyl ( i-Bu, i-butyl, -CH2CH(CH3)2), 2-butyl (s-Bu, s-butyl, -CH(CH3)CH2CH3), 2-methyl-2-propyl (t-Bu, t-butyl, -C(CH3)3), 1-pentyl (n-pentyl, -CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH3)CH2CH2CH3), 3-pentyl (-CH(CH2CH3)2), 2-methyl-2-butyl (-C(CH3)2CH2CH3), 3-methyl-2-butyl (-CH(CH3)CH(CH3)2), 3-Methyl-1-butyl (-CH2CH2CH(CH3)2), 2-methyl-1-butyl (-CH2CH(CH3)CH2CH3), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH2CH2CH2CH3), 3-hexyl (-CH(CH2CH3)(CH2CH2CH3)), 2-methyl-2-pentyl (-C(CH3)2CH2CH2CH3), 3-methyl-2-pentyl (-CH(C H3)CH(CH3)CH2CH3), 4-methyl-2-pentyl (-CH(CH3)CH2CH(CH3)2), 3-methyl-3-pentyl (-C(CH3)(CH2CH3)2), 2-methyl-3-pentyl (-CH(CH2CH3)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH3)2CH(CH3)2), 3,3-dimethyl-2-butyl (-CH(CH3)C(CH3)3 and octyl (-(CH2)7CH3).

[0058] As used herein, unless otherwise specified, "heteroalkyl" refers to an alkyl group in which at least one carbon atom is replaced by a non-carbon atom, such as an N atom, an O atom, an S atom, a P atom, or the like. O, N, and S are used as examples for illustration. For example, if the carbon atom connected to an adjacent group in an alkyl group is replaced by a non-carbon atom O, N, or S, the resulting heteroalkyl group is an alkoxy group (e.g., -OCH3, etc.), an amino group (e.g., -NHCH3, -N(CH3)2, etc.), or a thioalkyl group (e.g., -SCH3). If the carbon atom not directly connected to an adjacent group in an alkyl group is replaced by a non-carbon atom O, N, or S, the resulting heteroalkyl group is an alkoxyalkyl group (e.g., -CH2CH2-O-CH3, etc.), an alkylaminoalkyl group (e.g., -CH2NHCH3, -CH2N(CH3)2, etc.), or an alkylthioalkyl group (e.g., -CH2-S-CH3). If the terminal carbon atom of an alkyl group is replaced by a non-carbon atom, the resulting heteroalkyl group can be a hydroxyalkyl group (e.g., -CH2CH2-OH), an aminoalkyl group (e.g., -CH2NH2), or a mercaptoamino group (e.g., -CH2CH2-SH). Phrases containing the term "heteroalkyl" such as "C1-C9 heteroalkyl" or "C 1～9 “Heteroalkyl” refers to a heteroalkyl group containing 1 to 9 carbon atoms, which at each occurrence can be independently C1 heteroalkyl, C2 heteroalkyl, C3 heteroalkyl, C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl or C9 heteroalkyl.

[0059] In this article, unless otherwise specified, "cycloalkyl" has the same meaning as "non-aromatic cyclic hydrocarbon group", which refers to a monovalent residue formed by a non-aromatic hydrocarbon (saturated hydrocarbon or unsaturated hydrocarbon) containing a ring carbon atom losing a hydrogen atom on the ring, that is, a monovalent connection site is formed directly on the ring. Cycloalkyl derived from non-aromatic saturated hydrocarbons can be recorded as saturated cycloalkyl, and cycloalkyl derived from non-aromatic unsaturated hydrocarbons can be recorded as unsaturated cycloalkyl. Cycloalkyl can be a monocyclic alkyl, a spirocyclic alkyl, or a bridged cycloalkyl. Phrases containing this term, such as "C 3～ C9 cycloalkyl" or C 3～9 "Cycloalkyl" refers to a cycloalkyl group containing 3 to 9 carbon atoms, each occurrence of which can be independently C3 cycloalkyl, C4 cycloalkyl, C5 cycloalkyl, C6 cycloalkyl, C7 cycloalkyl, C8 cycloalkyl or C9 cycloalkyl. Suitable examples include, but are not limited to, cyclopropyl Cyclobutyl Cyclopentyl Cyclohexyl In addition, "cycloalkyl" may also contain one or more double bonds, and representative examples of cycloalkyl containing double bonds include cyclopentenyl (including but not limited to ), cyclohexenyl (including but not limited to ), cyclohexadiene (including but not limited to ) group, cyclopentadienyl (including but not limited to ) and cyclobutadienyl (including but not limited to ).

[0060] As used herein, unless otherwise specified, "heterocycloalkyl" refers to a cycloalkyl group in which at least one carbon atom is replaced by a non-carbon atom, which may be a N atom, an O atom, an S atom, or the like, and may be a saturated ring or a partially unsaturated ring. Phrases containing this term, for example, "C4-C9 heterocyclyl" refers to a heterocyclyl group containing 4 to 9 carbon atoms, which, at each occurrence, may be independently C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl, or C9 heteroalkyl. Suitable examples include, but are not limited to, dihydropyridyl, tetrahydropyridyl (piperidyl), tetrahydrothienyl, sulfur-oxidized tetrahydrothienyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and dihydroindole.

[0061] In this article, unless otherwise specified, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic hydrocarbon compound by losing a hydrogen atom, that is, a monovalent linking site formed directly on the ring. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic aromatic groups, at least one is an aromatic ring system. For example, "C6-C 10 "Aryl" refers to an aromatic group containing 6 to 10 carbon atoms, each occurrence of which can be independently C6 aryl, C8 aryl, C9 aryl or C 10 Aryl. For example, "C6~C 20 "Aryl" refers to an aromatic group containing 6 to 20 carbon atoms, each occurrence of which can be independently but not limited to C6 arylaryl (such as phenyl), C6 arylaryl (such as benzocyclobutenyl), C8 aryl (such as phenylcyclobutenyl), C9 aryl (such as indenyl), C 10 Aryl (such as naphthyl), C 12 Aryl (such as acenaphthenyl, biphenyl), C 13 Aryl (such as fluorenyl), C 14 Aryl (such as anthracenyl, phenanthrenyl), C 18 Aryl (such as triphenylene) or C 20 Aryl (eg, perylene). Examples of suitable aromatic cyclic hydrocarbon compounds include, but are not limited to, benzene, stycyclobutene, biphenyl, indene, naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, triphenylene, perylene, and derivatives thereof.

[0062] In this article, unless otherwise specified, "heteroaryl" refers to a heterocyclic group with aromaticity, which can be a monovalent group formed by replacing at least one carbon atom of an aryl group with a non-carbon atom, or a monovalent group formed by replacing at least one carbon atom of a cyclopentadienyl group with a non-carbon atom, wherein the non-carbon atom can be, but is not limited to, a nitrogen atom, an oxygen atom, or a sulfur atom. For example, "C1-C 10 The term "heteroaryl" refers to a heteroaryl group containing 1 to 10 carbon atoms, which can be independently C1 heteroaryl (such as tetrazolyl, etc.), C2 heteroaryl (such as triazolyl, oxadiazolyl, etc.), C3 heteroaryl (such as imidazolyl, etc.), C4 heteroaryl (such as furyl, etc.), C5 heteroaryl (such as pyridyl, etc.), C6 heteroaryl, C7 heteroaryl (such as benzimidazole, etc.), C8 heteroaryl (such as indolyl, etc.), C9 heteroaryl (such as quinolyl, etc.) or C 10 Heteroaryl (such as pyrrolobipyridinyl). Also for example, "C3~C 20 "Heteroaryl" refers to a heteroaryl group containing 3 to 20 carbon atoms, each occurrence of which can be independently but not limited to C2 heteroaryl, C3 heteroaryl, C4 heteroaryl, C5 heteroaryl, C6 heteroaryl, C8 heteroaryl, C9 heteroaryl, C 10 Heteroaryl, C 12 Heteroaryl, C 13 Heteroaryl, C 14 Heteroaryl, C 18 Heteroaryl or C 20 Heteroaryl. Suitable examples include, but are not limited to, heteroaryl groups derived from the following heteroaromatic rings (number of carbon atoms is indicated in brackets): furan (C4), benzofuran (C8), thiophene (C4), benzothiophene (C8), pyrrole (C4), pyrazole (C3), triazole (C2), imidazole (C3), oxazole (C3), oxadiazole (C2), thiazole (C3), tetrazole (C1), indole (C8), carbazole (C 12 ), pyrroloimidazole (C5), pyrrolopyrrole (C6), thienopyrrole (C6), thienothiophene (C6), furopyrrole (C6), furofuran (C6), thienofuran (C6), thienopyridine (C7), furopyridine (C7), benzoxazole (C7), benzisoxazole (C7), benzothiazole (C7), benzisothiazole (C7), benzimidazole (C7), pyridine (C5), pyrazine (C4), pyridazine (C4), pyrimidine (C4), triazine (C3), quinoline (C9), isoquinoline (C9), naphthyridine (C8, such as o-naphthyridine), quinoxaline (C8), phenanthridine (C 13 ), primary pyridine (C 11 ), quinazoline (C8) and quinazolinone (C8).

[0063] As used herein, unless otherwise specified, "alkylene" refers to a hydrocarbon group having two monovalent radical centers derived from an alkane by removing two hydrogen atoms (or derived from an alkyl group by losing another hydrogen atom), which may be a saturated branched alkyl group or a saturated straight-chain alkyl group. For example, "C1-C9 alkylene" means that the alkyl portion contains 1 to 9 carbon atoms, and each occurrence may be independently C1 alkylene, C2 alkylene, C3 alkylene, C4 alkylene, C5 alkylene, C6 alkylene, C7 alkylene, C8 alkylene or C9 alkylene. Suitable examples include, but are not limited to, methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-) and 1,4-butyl (-CH2CH2CH2CH2-)

[0064] As used herein, "halogen" or "halo" refers to F, Cl, Br or I, unless otherwise specified.

[0065] As used herein, unless otherwise specified, "amino group" may be a primary amino group (-NH2), a secondary amino group (>NH), a tertiary amino group (>N-) or a quaternary amino group (>N+<).

[0066] Herein, unless otherwise specified, a hydroxyl group is -OH, a carboxyl group is -COOH, a cyano group is -CN, a hydrazine group is -NHNH2, a sulfinic acid group is -S(=O)OH, a phosphinic acid group is (*-)2P(=O)OH, a sulfonic acid group is -S(=O)2OH, a phosphate group is (*-)P(=O)(OH)2, and a boronic acid group is (*-)B(OH)2. The * in the phosphinic acid group indicates that the group is connected to a carbon atom or H and at least one of the groups is connected to a carbon atom, the * in the phosphonic acid group indicates that the group is connected to a carbon atom, and the * in the boronic acid group indicates that the group is connected to a carbon atom.

[0067] Currently, the photoelectric conversion efficiency of perovskite solar cells using organic electron transport layer materials still needs to be further improved, and the stability of the cells is poor, which limits the industrial large-scale production of perovskite solar cells using organic electron transport layers. This application proposes a perovskite solar cell that can effectively improve the photoelectric conversion efficiency and stability of perovskite solar cells by adjusting the composition of the materials forming the organic electron transport layer.

[0068] Referring to FIG1 , one embodiment of the present application provides a transverse perovskite solar cell 1. The perovskite solar cell 1 includes a transparent electrode layer 11 and a hole transport layer 12, a perovskite layer 13, an electron transport layer 14, and a metal electrode 15 sequentially disposed on the transparent electrode layer 11.

[0069] The electron transport layer 14 includes an organic electron transport material, a first additive, and a second additive; the first additive includes one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile, and poly-4-vinylpyridine;

[0070] The second additive includes one or more of the following compounds of formula I and formula II:

[0071] Wherein, R1, R2, R3, R5, and R6 are independently selected from C1-C4 alkyl groups; n1 and n2 are independently integers of 1-6; m1 and m2 are independently integers of 1-4; R4 and R7 are independently C1-C5 alkyl groups, C1-C5 alkoxy groups, C1-C5 alkylthiol groups, aryl groups, halogen groups, carboxyl groups, cyano groups, or are absent; X is one or more of Cl, Br, I, BF4, PF6, and TFSI; Y1 and Y2 are independently selected from any one of CH2, NH, O, and S, or are absent. Wherein, "absent" means that the group is H.

[0072] Conventional perovskite solar cells 1 using organic electron transport layer materials have limited photovoltaic performance and photoelectric conversion efficiency due to the poor conductivity of the organic electron transport material. Furthermore, the organic electron transport material's poor dispersibility in solvents leads to severe agglomeration, which affects the film uniformity of the electron transport layer 14 and results in poor stability for cells using organic electron transport materials as the electron transport layer 14. These factors have hindered the large-scale industrial application of perovskite solar cells 1 using organic electron transport materials as the electron transport layer 14.

[0073] The perovskite solar cell 1 mentioned above in the present application adds a specific organic polymer as a first additive in the electron transport layer 14 using an organic electron transport material, and adds a specific quaternary ammonium salt and / or tertiary amine molecule as a second additive. Among them, the introduction of the above-mentioned organic polymer can improve the dispersibility of the organic electron transport material in the solution forming the electron transport layer 14, reduce the agglomeration of the organic electron transport material, and can improve the film uniformity of the electron transport layer 14, thereby improving the photoelectric conversion efficiency of the device; the introduction of the above-mentioned quaternary ammonium salt can significantly improve the film conductivity of the electron transport layer 14, thereby improving the photoelectric conversion efficiency of the perovskite solar cell; the introduction of the above-mentioned tertiary amine molecules can enhance the binding force with the transport layer molecules through the binding effect of N atoms and the electron transport layer 14, improve molecular orientation, and enhance the electron mobility of the electron transport layer 14.

[0074] Furthermore, the hydrophobic functional groups in the above-mentioned organic polymer can reduce the entry channels of water molecules in the electron transport layer 14, relieving the reaction of water with the perovskite through the electron transport layer 14, thereby improving the stability of the device; the above-mentioned quaternary ammonium salt and tertiary amine molecules can reduce the diffusion of perovskite ions by forming a passivation layer with the perovskite interface during the molecular crystallization process of the electron transport layer 14, inhibiting the decomposition of perovskite and improving the stability of the device. Through the combined action of the above-mentioned specific first additive and second additive, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 using organic electron transport materials can be effectively improved.

[0075] It can be understood that the electron transport layer 14 of the perovskite solar cell 1 may include only the organic electron transport material, the above-mentioned organic polymer first additive and the above-mentioned quaternary ammonium salt second additive; may include only the organic electron transport material, the above-mentioned organic polymer first additive and the above-mentioned tertiary amine molecule second additive; or may include the organic electron transport material, the above-mentioned organic polymer first additive, the above-mentioned quaternary ammonium salt second additive and the above-mentioned tertiary amine molecule second additive at the same time.

[0076] It can be understood that R1, R2, R3, R5 and R6 in the molecules of the above-mentioned compounds of formula I and formula II can be methyl, ethyl, n-propyl, n-butyl, isopropyl, isobutyl, tert-butyl, etc., respectively; n1 and n2 can be 1, 2, 3, 4, 5, respectively; m1 and m2 can be 1, 2, 3, 4, respectively.

[0077] In some embodiments, based on the total mass of the electron transport layer 14, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%. When the amounts of the first additive, the second additive, and the organic electron transport material in the electron transport layer 14 are within the above ranges, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 can be further improved.

[0078] In some embodiments, the second additive includes a compound of Formula I and a compound of Formula II, and the mass ratio of the compound of Formula I to the compound of Formula II is (0.5-2):1. Thus, by simultaneously using the compound of Formula I and the compound of Formula II in the electron transport layer 14, and controlling the mass ratio of the compound of Formula I to the compound of Formula II within the range of (0.5-2):1, the specific amount of the quaternary ammonium salt second additive, the tertiary amine molecule second additive, and the organic polymer first additive in conjunction with the organic electron transport material can further improve the photoelectric conversion efficiency and stability of the perovskite solar cell 1.

[0079] In some embodiments, the compound of formula I is one or more of tetrabutylammonium tetrafluoroborate, hexamethylammonium iodide, and dodecyltrimethylammonium bromide; the compound of formula II is one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

[0080] In some embodiments, the thickness of the electron transport layer is 25 nm to 45 nm. It is understood that the thickness of the electron transport layer can be, but is not limited to, 25 nm, 28 nm, 30 nm, 32 nm, 35 nm, 38 nm, 40 nm, 42 nm, or 45 nm.

[0081] In some embodiments, the organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, perylene diimide and its derivatives. Among them, the fullerene derivative can be PCBM ([6,6]-phenyl-C 61 -isomethyl butyrate), [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM), C 60 -PDI(C 60 -perylene diimide) etc.

[0082] In some embodiments, the transparent conductive layer 11 may be made of a transparent conductive oxide, such as FTO (fluorine-doped tin oxide, SnO2:F), ITO (tin-doped indium oxide), BZO (boron-doped zinc oxide), AZO (aluminum zinc oxide), or IZO (indium zinc oxide). These transparent oxides may be deposited on a substrate, which may be a rigid substrate or a flexible substrate. In some embodiments, the substrate may be transparent glass.

[0083] The hole transport layer 12 can use hole transport materials commonly used in the art. In a specific example, the hole transport layer 12 uses PTAA (polytriarylamine), Spiro-OMeTAD (tetrakis(N,N-p-anisyl)-9,9'-spirobifluorene) or Me-4PACz ([4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid).

[0084] The perovskite layer 13 may be a perovskite component commonly used in the art, and the chemical formula of the perovskite component satisfies ABX3 or A2CDX6; wherein A is an inorganic monovalent cation or an organic monovalent cation or a mixture of the two, and A includes FA + 、MA + 、Cs + , Rb + , K + DMA + , EA + , GA +One or more of; B is an inorganic divalent metal cation, B includes Pb 2+ 、Ge 2+ 、Cd 2+ 、Sb 2+ 、Zn 2+ 、Mn 2+ , Ca 2+ One or more of the following; C is a noble metal cation, commonly Ag + D is a heavy metal or rare metal trivalent cation, which can be a bismuth cation Bi 3+ 、Antimony cation Sb 3+ , and indium cations In 3+ At least one of; X is oxygen or a halogen element or a pseudo-halogen element, X includes I - Br - 、Cl - 、SCN - HCOO - 、CH3COO - CF3COO - 、CH3SO3 - CF3SO3 - 、CN - In a specific example, the perovskite component is Cs 0.05 MA 0.1 FA 0.85 PbI3; MA is methylammonium and FA is formamidine.

[0085] The metal electrode 15 may be an electrode commonly used in the art, such as Au, Ag, Cu, Al, Pt, etc. In a specific example, the metal electrode 15 is an Ag electrode.

[0086] One embodiment of the present application provides a method for preparing the above-mentioned perovskite solar cell 1, which comprises the following steps S100 to S500:

[0087] Step S100: providing a transparent electrode layer 11 .

[0088] The transparent electrode layer 11 serves as a device substrate. Specifically, the transparent electrode layer 11 can be made of FTO glass. Before forming the hole transport layer 12 on the transparent electrode layer 11 , the transparent electrode layer 11 is first subjected to UV cleaning treatment to remove impurities on the surface of the transparent electrode layer 11 .

[0089] In a specific example, the transparent electrode layer 11 is made of FTO glass.

[0090] Step S200 : forming a hole transport layer 12 on the transparent electrode layer 11 .

[0091] A solution containing a hole transport material is spin-coated on one surface of the transparent electrode layer 11 by a spin-coating process, and the hole transport layer 12 is formed after annealing.

[0092] The spin coating process parameters (such as spin coating speed, spin coating time, etc.) when preparing the hole transport layer 12 can be specifically set according to the actual conditions such as the thickness of the hole transport layer 12 to be prepared. Similarly, the annealing temperature can also be set according to actual production conditions.

[0093] It is understood that the material forming the hole transport layer 12 may be a conventional hole transport material in the art.

[0094] In a specific example, the hole transport material is PTAA, the spin coating speed is 5000 rpm / s, the spin coating time is 30 s, and the annealing temperature is 100°C.

[0095] Step S300 : forming a perovskite layer 13 on the hole transport layer 12 .

[0096] A solution containing a perovskite component is spin-coated on the surface of the hole transport layer 12 away from the transparent electrode layer 11 by a spin-coating process, and the perovskite layer 13 is formed after annealing.

[0097] The spin coating process parameters (such as spin coating speed, spin coating acceleration, spin coating time, etc.) when preparing the perovskite layer 13 can be specifically set according to the actual conditions such as the thickness of the perovskite layer 13 to be prepared. The annealing temperature can also be set according to actual production conditions.

[0098] It can be understood that the perovskite layer 13 can adopt perovskite components commonly used in the art.

[0099] In a specific example, the perovskite component is Cs 0.05 MA 0.1 FA 0.85 PbI3, the spin coating speed is 5000 rpm / s, the spin coating acceleration is 2000 rpm / s, the spin coating time is 30s, and the annealing temperature is 100℃.

[0100] Step S400 : forming an electron transport layer 14 on the perovskite layer 13 .

[0101] Electron transport layer 14 can be formed without annealing by spin-coating a solution containing an organic electron transport material, a first additive, and a second additive onto the surface of perovskite layer 13 away from hole transport layer 12. The solution includes a solvent and a solute dispersed in the solvent, wherein the solute includes the organic electron transport material, the first additive, and the second additive. The types of the organic electron transport material, the first additive, and the second additive in electron transport layer 14 are as described above and are not further described here.

[0102] It is understood that the spin coating process parameters (such as spin coating speed, spin coating time, etc.) when preparing the electron transport layer 14 can be specifically set according to the actual situation such as the thickness of the electron transport layer 14 to be prepared. The electron transport layer 14 can be made of organic electron transport materials commonly used in the art.

[0103] In a specific example, the spin coating speed is 2000 rpm / s, the spin coating time is 30 s, and the organic electron transport material is PCBM.

[0104] In some embodiments, the solvent in the solution for forming the electron transport layer 14 includes a first organic solvent and a second organic solvent, wherein the first organic solvent is a low-boiling-point solvent with a boiling point of 38° C. to 70° C., and the second organic solvent is a high-boiling-point solvent with a boiling point of 110° C. to 210° C.

[0105] In some embodiments, the first organic solvent includes one or more of chloroform (boiling point of about 61° C.), dichloromethane (boiling point of about 39.75° C.), and tetrahydrofuran (boiling point of about 66° C.). The second organic solvent includes one or more of chlorobenzene (boiling point of about 132.2° C.), o-dichlorobenzene (boiling point of about 180.4° C.), toluene (boiling point of about 110.6° C.), o-xylene (boiling point of about 144.4° C.), anisole (boiling point of about 153.8° C.), 2-methylanisole (boiling point of about 170° C.), 2-chlorophenol (boiling point of about 174° C.), and 1,2,3,4-tetrahydronaphthalene (boiling point of about 207.2° C.).

[0106] In some embodiments, based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%. It is understood that the volume fraction of the first organic solvent can be, but is not limited to, 20%, 30%, 40%, 50%, 60%, 70%, or 80%; accordingly, the volume fraction of the second organic solvent can be, but is not limited to, 80%, 70%, 60%, 50%, 40%, 30%, or 20%. In a specific example, the volume ratio of the first organic solvent to the second organic solvent is 1:1, that is, the high-boiling-point solvent and the low-boiling-point solvent are mixed in equal volumes, and the volume fraction of each is 50%.

[0107] In some embodiments, in the solution forming the electron transport layer 14 , the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

[0108] In some embodiments, in the solute forming the electron transport layer 14 , the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

[0109] Step S500 : forming a metal electrode 15 on the electron transport layer 14 .

[0110] The metal electrode 15 is prepared on the electron transport layer 14 by a thermal evaporation process, wherein the evaporation rate of the thermal evaporation process can be set according to actual needs; the material of the metal electrode 15 can also be an electrode material commonly used in the art.

[0111] In one specific example, the evaporation rate is A metal Ag electrode with a thickness of 110 nm was prepared.

[0112] The method for preparing the perovskite solar cell 1 of the present application uses a spin coating process to spin-coat a solution containing an organic electron transport material, a first additive, and a second additive onto the perovskite layer 13 to prepare the electron transport layer 14. By using the first additive and the second additive specified in the present application in the electron transport layer 14, the photoelectric conversion efficiency and stability of the perovskite solar cell 1 can be effectively improved.

[0113] Furthermore, by using a mixed solvent including a first organic solvent and a second organic solvent, the first organic solvent is a low-boiling-point solvent and the second organic solvent is a high-boiling-point solvent, the first organic solvent and the second organic solvent are mixed in a specific volume ratio; the organic electron transport material, the first additive and the second additive are dispersed in the mixed solvent system. By adjusting the volume ratio of different solvents based on the differences in boiling point and viscosity (generally, solvents with high boiling points also have high viscosity, and solvents with low boiling points also have low viscosity), the crystallization order and uniformity of the organic electron transport material molecules and the first additive and the second additive can be optimized, and the molecular orientation can be guided, thereby enhancing the film quality and conductivity of the electron transport layer 14 and improving the photoelectric conversion efficiency and stability of the perovskite solar cell 1.

[0114] One embodiment of the present application provides a photovoltaic module, comprising the perovskite solar cell described above. The photovoltaic module of the present application has high photoelectric conversion efficiency and good stability by adopting the perovskite solar cell of the present application.

[0115] The above-mentioned photovoltaic module includes one or more perovskite solar cells, which can be selected according to the specific application scenario; further, the above-mentioned photovoltaic module includes multiple perovskite solar cells, and the multiple perovskite solar cells are connected in series or in parallel to form a battery cell.

[0116] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a back sheet.

[0117] Adhesive layers are provided on both surfaces of the cell, a back plate is provided on the surface of one of the adhesive layers away from the cell, and a photovoltaic glass layer is provided on the surface of the other adhesive layer away from the cell.

[0118] The photovoltaic glass layer and back panel are used to protect the perovskite solar cells, and have the functions of sealing, insulation and waterproofing; the bonding layer plays the role of bonding the photovoltaic glass layer and the battery cell, and bonding the back panel and the battery cell.

[0119] Optionally, the photovoltaic glass layer is made of tempered glass, the back panel is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0120] Furthermore, the photovoltaic module further includes a junction box and an outer frame.

[0121] The junction box is used to protect the power generation system of the entire photovoltaic module. It is equivalent to a current transfer station. When a battery cell short-circuits, the junction box will automatically disconnect the short-circuited battery string.

[0122] The outer frame can support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0123] Furthermore, silicone is used to bond and seal the connection between the frame and other parts of the photovoltaic module. Photovoltaic modules can convert solar energy into electrical energy, which can be stored in batteries or used to drive loads.

[0124] In some embodiments, the photovoltaic component is a solar panel.

[0125] An embodiment of the present application provides a photovoltaic system, including the photovoltaic assembly described above.

[0126] The photovoltaic system utilizes the perovskite solar cells in the above-mentioned photovoltaic modules to directly convert solar radiation energy into electrical energy with high efficiency and good stability; further, the above-mentioned photovoltaic system is a photovoltaic power generation system.

[0127] Photovoltaic modules are the core part of photovoltaic power generation systems. The above photovoltaic system includes one or more photovoltaic modules, which can be selected according to the specific application scenario; further, when the above photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0128] The above photovoltaic system can be an independent photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0129] An independent photovoltaic power generation system consists of a photovoltaic array, a battery pack, a charge controller, a power electronic converter (inverter), and a load. Its operating principle is that solar radiation energy is first converted into electrical energy by the photovoltaic array, then converted by the power electronic converter to power the load. Meanwhile, excess electrical energy is stored as chemical energy in an energy storage device after passing through the charge controller. In this way, when sunlight is insufficient, the energy stored in the battery can be converted into 220V, 50Hz AC electricity after passing through the power electronic inverter, filtering, and power frequency transformer to supply the AC load.

[0130] A grid-connected photovoltaic power generation system consists of a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and system monitoring. Its operating principle is that solar radiation energy is converted by the photovoltaic array, then converted to high-voltage DC through high-frequency DC conversion. This is then inverted by a power electronic inverter and output to the grid as a sinusoidal AC current with a frequency consistent with the grid voltage.

[0131] The above two photovoltaic power generation systems have their own characteristics and can be selected according to specific application scenarios.

[0132] Please refer to FIG. 2 . An embodiment of the present application provides an electrical device 2 . The electrical device 2 includes the perovskite solar cell described above in the present application.

[0133] In some embodiments, the power-consuming device 2 is a common device including the solar cell of the present application, such as in the fields of communications, transportation, industry and agriculture, lighting, etc. The power-consuming device 2 may include, for example, satellites, communications equipment, traffic lights, lighthouses, wireless phone booths, monitoring equipment in the oil drilling field, power supply systems, camping lights, electric vehicles, electronic device chargers, building curtain walls, etc.

[0134] Below, the embodiment of the present application is described. The embodiment described below is exemplary and is only used to explain the present application, and is not to be construed as limiting the present application. Where specific techniques or conditions are not specified in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. Reagents or instruments used that do not specify the manufacturer are conventional products that can be obtained commercially.

[0135] 1. Perovskite Solar Cells

[0136] Example 1:

[0137] 1) Transparent electrode layer

[0138] The FTO glass was UV cleaned and used as the transparent electrode layer.

[0139] 2) Preparation of hole transport layer

[0140] A solution containing the hole transport material PTAA was spin-coated on the transparent electrode layer and annealed to form a hole transport layer. The spin-coating speed was 5000 rpm / s, the spin-coating time was 30 seconds, the annealing temperature was 100°C, the annealing time was 10 minutes, and the thickness of the hole transport layer was 15 nm.

[0141] 3) Preparation of perovskite layer

[0142] A solution containing raw materials of perovskite components is spin-coated on the hole transport layer and annealed to form a perovskite layer. The spin-coating speed is 5000 rpm / s, the spin-coating acceleration is 2000 rpm / s, the spin-coating time is 30s, the annealing temperature is 100°C, the annealing time is 15min, and the perovskite component is Cs 0.05 MA 0.1 FA 0.85 PbI3, the thickness of the perovskite layer is 600nm.

[0143] 4) Preparation of electron transport layer

[0144] An organic electron transport material, PCBM, a first additive, polymethyl methacrylate, and a second additive, tetrabutylammonium tetrafluoroborate, are dispersed in a mixed solvent to form an electron transport layer solution. The mixed solvent in the electron transport layer solution is 2-methylanisole and chloroform in a volume ratio of 1:1.

[0145] The electron transport layer solution was spin-coated onto the perovskite layer, and the solvent was removed to form the electron transport layer. The spin coating speed was 2000 rpm / s, and the spin coating time was 30 seconds. The mass fraction of PCBM in the electron transport layer was 94%, the mass fraction of polymethyl methacrylate was 5%, and the mass fraction of the second additive, tetrabutylammonium tetrafluoroborate, was 1%. The thickness of the electron transport layer was 40 nm.

[0146] 5) Preparation of metal electrodes

[0147] A metal Ag electrode was formed on the electron transport layer using a thermal evaporation process. The evaporation rate was The thickness of the metal Ag electrode is 110 nm.

[0148] Example 2:

[0149] This embodiment is substantially the same as embodiment 1, with the only difference being the type of the first additive, which is a methacrylic acid-methyl methacrylate copolymer.

[0150] Example 3:

[0151] This embodiment is substantially the same as embodiment 1, with the only difference being the type of the first additive, which in this embodiment is poly-4-vinylpyridine.

[0152] Example 4:

[0153] This embodiment is substantially the same as embodiment 1, with the only difference being the type of the first additive, which in this embodiment is 4-vinylpyridine-styrene copolymer.

[0154] Example 5:

[0155] This embodiment is substantially the same as embodiment 1, with the only difference being the type of the second tertiary amine molecule additive. In this embodiment, the second additive is tris(dimethylaminoethyl)amine, CAS number: 33527-91-2.

[0156] Example 6:

[0157] This embodiment is substantially the same as embodiment 1, except that the second additive is a tertiary amine molecule. In this embodiment, the second additive is 1,7-bis(dimethylamino)heptane, CAS No. 29333-99-1.

[0158] Example 7:

[0159] This embodiment is substantially the same as embodiment 1, with the only difference being the type of the second tertiary amine molecule additive. In this embodiment, the second additive is 9,9-bis[3-(dimethylamino)propyl]fluorene, CAS number: 1821313-63-6.

[0160] Example 8:

[0161] This embodiment is substantially the same as embodiment 1, except that the type of the second additive is different. In this embodiment, the second additive is a quaternary ammonium salt additive represented by formula I. Specifically, the second additive is hexamethonium iodide, CAS number: 870-62-2.

[0162] Example 9:

[0163] This embodiment is substantially the same as embodiment 1, except that the type of the second additive is different. In this embodiment, the second additive is a quaternary ammonium salt additive represented by formula I. Specifically, the second additive is dodecyltrimethylammonium bromide, CAS number: 1119-94-4.

[0164] Example 10:

[0165] This embodiment is substantially the same as Example 1, differing only in the type of the second additive. In this embodiment, the second additive is a mixture of a quaternary ammonium salt additive represented by Formula I and a tertiary amine molecule additive represented by Formula II. Specifically, the second additive is a mixture of tetrabutylammonium tetrafluoroborate (CAS No. 429-42-5) and tris(dimethylaminoethyl)amine; the mass fraction of the quaternary ammonium salt additive in the electron transport layer is 1%, and the mass fraction of the tertiary amine molecule additive is 1%.

[0166] Example 11:

[0167] This embodiment is substantially the same as embodiment 1, with the only difference being the type of organic electron transport material. In this embodiment, the organic electron transport material is naphthalene diimide.

[0168] Example 12:

[0169] This embodiment is substantially the same as embodiment 1, with the only difference being the type of organic electron transport material. In this embodiment, the organic electron transport material is perylene diimide.

[0170] Example 13:

[0171] This embodiment is substantially the same as Example 1, differing only in the mass fractions of the organic electron transport material, the first additive, and the second additive in the electron transport layer. In this embodiment, the mass fraction of PCBM in the electron transport layer is 98%, the mass fraction of polymethyl methacrylate is 1%, and the mass fraction of the second additive, tetrabutylammonium tetrafluoroborate, is 1%.

[0172] Example 14:

[0173] This embodiment is substantially the same as embodiment 1, with the only difference being the mixed solvent used in the solution for forming the electron transport layer. In this embodiment, the mixed solvent is chlorobenzene and dichloromethane in a volume ratio of 1:2.

[0174] Comparative Example 1:

[0175] This comparative example is substantially the same as Example 1, except that the first additive and the second additive are not used in the electron transport layer.

[0176] Comparative Example 2:

[0177] This comparative example is substantially the same as Example 1, except that the type of polymer additive in the electron transport layer is different. In this comparative example, the polymer additive is polyethylene.

[0178] Comparative Example 3:

[0179] This comparative example is substantially the same as Example 1, except that the type of the second additive in the electron transport layer is different. In this comparative example, the second additive is tris(3-aminopropyl)amine, CAS No. 4963-47-7.

[0180] 2. Performance measurement of solar cells

[0181] 1) Photoelectric conversion efficiency test

[0182] At 25°C, the perovskite solar cell was placed in sunlight through a test fixture with a light power density of 100mW / cm 2 Specifically, the test fixture and Keithley 2400 digital source meter were connected using the four-wire method. The starting voltage was set to -0.2V, the cutoff voltage was set to 1.2V, and the scan speed was set to 200mV / s. Reverse / forward scans were performed to record the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF).

[0183] Then, the photoelectric conversion efficiency (PCE) of the perovskite solar cell was calculated using the following formula: PCE = Jsc × Voc × FF / optical power density × 100%.

[0184] 2) Light aging test

[0185] Specific testing process: The perovskite solar cell is placed under sunlight at 85°C with a light power density of 100mW / cm 2 , through nitrogen box packaging, the maximum power point voltage of the solar cell is dynamically monitored, and the time, power, current and voltage are recorded. The perovskite solar cell is aged in nitrogen for 1000h.

[0186] After removing the perovskite solar cell, the aforementioned photoelectric conversion efficiency test was performed. Specifically, a four-wire method was used to connect the test fixture to a Keithley 2400 SourceMeter instrument. The starting voltage was set to -0.2V, the cutoff voltage was set to 1.2V, and the scan rate was set to 200mV / s. Forward and reverse scans were performed, and the short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF) were recorded.

[0187] The photoelectric conversion efficiency (PCE) of the photo-aged perovskite solar cell was then calculated and compared with the PCE of the unaged perovskite solar cell. The results of the photo-aging test reflect the stability of the perovskite solar cell. Given the same aging time, the closer the efficiency after aging is to the initial efficiency, the better the cell's stability.

[0188] The parameters and performance data of the perovskite solar cells of the above embodiments and comparative examples are shown in Tables 1 and 2.

[0189] Table 1

[0190] Table 2

[0191] It can be seen from the above embodiments and comparative examples that the electron transport layer of the organic electron transport material in the battery of each embodiment of the present application uses a specific polymer macromolecule containing lone pair electrons such as O and N as the first additive, and uses a specific quaternary ammonium salt of the compound of general formula I and a tertiary amine molecule of the compound of general formula II as the second additive. The photoelectric conversion efficiency and stability of the perovskite solar cell are better than those of comparative examples 1 to 3.

[0192] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0193] The above-described embodiments merely represent several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent. It should be noted that a person of ordinary skill in the art may make several variations and improvements without departing from the inventive concept of the present application, and these variations and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the patent in this application shall be based on the appended claims, and the description and drawings may be used to interpret the content of the claims.

Claims

1. A perovskite solar cell, comprising a transparent electrode layer and a perovskite layer, an electron transport layer and a metal electrode sequentially arranged on the transparent electrode layer; The electron transport layer includes an organic electron transport material, a first additive and a second additive; The first additive comprises one or more of polymethyl methacrylate, methacrylic acid-methyl methacrylate copolymer, 4-vinylpyridine-styrene copolymer, polyacrylonitrile and poly-4-vinylpyridine; The second additive comprises one or more of the following compounds of formula I and formula II: in, R1, R2, R3, R5 and R6 are independently selected from C1-C4 alkyl groups; n1 and n2 are independently integers of 1-6; m1 and m2 are independently integers of 1-4; R4 and R7 are independently C1-C5 alkyl groups, C1-C5 alkoxy groups, C1-C5 alkylthiol groups, aryl groups, halogen groups, carboxyl groups, cyano groups or are absent; X is one or more of Cl, Br, I, BF4, PF6 and TFSI; Y1 and Y2 are independently selected from any one of CH2, NH, O and S or are absent.

2. The perovskite solar cell according to claim 1, wherein: Based on the total mass of the electron transport layer, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

3. The perovskite solar cell according to claim 1 or 2, wherein: The second additive includes the compound of formula I and the compound of formula II, and the mass ratio of the compound of formula I to the compound of formula II is (0.5-2):

1.

4. The perovskite solar cell according to any one of claims 1 to 3, wherein The compound of formula I includes one or more of tetrabutylammonium tetrafluoroborate, hexamethylammonium iodide, and dodecyltrimethylammonium bromide.

5. The perovskite solar cell according to any one of claims 1 to 4, wherein The compound of formula II includes one or more of 1,7-bis(dimethylamino)heptane, tris(dimethylaminopropyl)amine, and 9,9-bis[3-(dimethylamino)propyl]fluorene.

6. The perovskite solar cell according to any one of claims 1 to 5, wherein The thickness of the electron transport layer is 25 nm to 45 nm.

7. The perovskite solar cell according to any one of claims 1 to 6, wherein The organic electron transport material includes one or more of fullerene derivatives, naphthalene diimide and its derivatives, perylene diimide and its derivatives.

8. The method for preparing a perovskite solar cell according to any one of claims 1 to 7, comprising the following steps: Providing the transparent electrode layer; as well as forming the perovskite layer, the electron transport layer and the metal electrode in sequence on the transparent electrode layer; The solution forming the electron transport layer includes a solvent and a solute dispersed in the solvent, wherein the solute includes The organic electron transport material, the first additive and the second additive.

9. The method for preparing a perovskite solar cell according to claim 8, wherein: The solvent includes a first organic solvent and a second organic solvent, the first organic solvent has a boiling point of 38°C to 70°C, and the second organic solvent has a boiling point of 110°C to 210°C.

10. The method for preparing a perovskite solar cell according to claim 9, wherein: The first organic solvent includes one or more of chloroform, dichloromethane and tetrahydrofuran.

11. The method for preparing a perovskite solar cell according to claim 9 or 10, wherein: The second organic solvent includes one or more of chlorobenzene, o-dichlorobenzene, toluene, o-xylene, anisole, 2-methylanisole, 2-chlorophenol and 1,2,3,4-tetralin.

12. The method for preparing a perovskite solar cell according to any one of claims 9 to 11, wherein: Based on the total volume of the solvent, the volume fraction of the first organic solvent is 20% to 80%, and the volume fraction of the second organic solvent is 20% to 80%.

13. The method for preparing a perovskite solar cell according to any one of claims 8 to 12, wherein: Based on the total mass of the solution, the mass fraction of the first additive is 0.2‰ to 1‰, the mass fraction of the second additive is 0.1‰ to 0.4‰, and the mass fraction of the organic electron transport material is 1.86% to 1.97%.

14. The method for preparing a perovskite solar cell according to any one of claims 8 to 13, wherein: Based on the total mass of the solute, the mass fraction of the first additive is 1% to 5%, the mass fraction of the second additive is 0.5% to 2%, and the mass fraction of the organic electron transport material is 93% to 98.5%.

15. A photovoltaic module comprising the perovskite solar cell according to any one of claims 1 to 7.

16. A photovoltaic system comprising the photovoltaic module according to claim 15.

17. An electrical device comprising at least one of the perovskite solar cell according to any one of claims 1 to 7 and the photovoltaic module according to claim 15.

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