Perovskite tandem solar cell and preparation method, photovoltaic module, system, electrical device, and power generation device

Abstract

The present application relates to a perovskite tandem solar cell and a preparation method, a photovoltaic module, a system, an electrical device, and a power generation device. The perovskite tandem solar cell comprises a first subcell, a composite layer, and a second subcell that are sequentially stacked. The composite layer comprises transparent conductive oxide nanoparticles and an insulating filler. In a spreading direction of the composite layer, there are gaps between at least some of the transparent conductive oxide nanoparticles and adjacent transparent conductive oxide nanoparticles thereof. The gaps are filled with at least part of the insulating filler. The perovskite tandem solar cell of the present application has high open circuit voltage, a high fill factor and high conversion efficiency.

Description

Perovskite tandem solar cell, preparation method, photovoltaic module, system, power utilization device and power generation device

[0001] Cross-reference to related applications

[0002] This application claims priority from Chinese Patent Application No. 202410867103.1, filed on June 28, 2024, entitled “Perovskite tandem solar cell, preparation method, photovoltaic module, system, power utilization device and power generation device”, which is incorporated by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of solar cells, in particular to a perovskite tandem solar cell, a preparation method, a photovoltaic module, a system, a power utilization device and a power generation device. BACKGROUND

[0004] With the rapid development of new energy field, solar cells have been widely used in military, aerospace, industry, commerce, agriculture and communication fields. Perovskite solar cells are devices that use the photoelectric conversion mechanism of perovskite type crystal materials to convert solar energy into electrical energy. They are the third generation of solar cells and have many advantages such as high photoelectric conversion efficiency, simple manufacturing process and low production cost. In recent years, they have been extensively studied.

[0005] A full perovskite tandem solar cell mainly consists of three parts: a narrow band gap perovskite sub-cell, a wide band gap perovskite sub-cell and an intermediate composite layer. The main role of the composite layer in the perovskite tandem solar cell is to recombine the electrons and holes generated by the light absorption of the upper and lower sub-cells, thereby forming a current in the external circuit and also serving as a connection between the upper and lower sub-cells.

[0006] Traditional perovskite tandem solar cells have the problem of low open-circuit voltage (Voc) and fill factor (FF), which affects the photoelectric conversion efficiency (PCE) of the cell. Therefore, how to improve the open-circuit voltage and fill factor of the perovskite tandem solar cell and improve the conversion efficiency of the cell has become one of the important directions of research in the field. SUMMARY

[0007] The present application is made in view of the above-mentioned problems, and one of its purposes is to provide a perovskite tandem solar cell with high open-circuit voltage and fill factor, and high conversion efficiency. Correspondingly, a preparation method, a photovoltaic module, a system, a power utilization device and a power generation device are also provided.

[0008] To achieve the above-mentioned purpose, the first aspect of the present application provides a perovskite tandem solar cell, comprising a first sub-cell, a composite layer and a second sub-cell which are sequentially stacked.

[0009] The composite layer comprises transparent conductive oxide nanoparticles and insulating fillers;

[0010] In the spreading direction of the composite layer, at least part of the transparent conductive oxide nanoparticles has a gap with adjacent transparent conductive oxide nanoparticles; the insulating fillers are filled in the gap.

[0011] By using transparent conductive oxide nanoparticles as the material of the composite layer, in the spreading direction of the composite layer, part of the transparent conductive oxide nanoparticles has a gap with adjacent transparent conductive oxide nanoparticles, so that the transparent conductive oxide nanoparticles in the composite layer are not continuous in the spreading direction; the transverse conductivity of the composite layer can be reduced, which is conducive to improving the fill factor of the perovskite tandem solar cell. By filling insulating fillers in the gap, not only the probability of contact between the transparent conductive oxide nanoparticles can be reduced, but also the direct contact between the charge transport layers of the upper and lower sub-cells can be blocked, and the probability of generating a reverse electric field can be reduced, thereby improving the open circuit voltage of the cell. Moreover, by using transparent conductive oxide nanoparticles as the main material of the composite layer, light can be diffracted through the gap between the particles when passing through the composite layer, which can reduce parasitic absorption. The perovskite tandem solar cell has a high open circuit voltage and fill factor, and has a high photoelectric conversion efficiency.

[0012] In any embodiment, the mass ratio of the transparent conductive oxide nanoparticles to the insulating fillers in the composite layer is 0.1-20:1. In this way, the insulating fillers can better fill the gap between the transparent conductive oxide nanoparticles, so that the composite layer has a lower transverse conductivity and effectively blocks the direct contact between the charge transport layers of the upper and lower sub-cells.

[0013] In any embodiment, the insulating fillers are insulating particles. In this way, the insulating fillers can play the role of filling and blocking the direct contact between the charge transport layers of the upper and lower sub-cells, and reduce the transverse conductivity of the composite layer.

[0014] In any embodiment, the particle size of the insulating particles is d1, the particle size of the transparent conductive oxide nanoparticles is d2, and 0≤|d1-d2|<200. In this way, the transparent conductive oxide nanoparticles 121 can be better dispersed, and the transverse conductivity of the composite layer 12 can be effectively reduced and the direct contact between the charge transport layers of the upper and lower sub-cells can be effectively blocked.

[0015] In any embodiment, d1 / d2 is 1:1-1:20. In this way, the particle size of the insulating particles is equal to or smaller than the particle size of the transparent conductive oxide nanoparticles, so that the insulating particles can better fill the gap formed by the transparent conductive oxide nanoparticles.

[0016] In any embodiment, d1 is 1 nm to 150 nm. In this way, the gaps formed by the transparent conductive oxide nanoparticles can be better filled.

[0017] In any embodiment, d1 is 2 nm to 40 nm. In this way, the insulating particles can be better filled into the gaps formed by the transparent conductive oxide nanoparticles, and better reduce the lateral conductivity of the composite layer and block the direct contact of the charge transport layers of the upper and lower sub-cells.

[0018] In any embodiment, d2 is 1 nm to 200 nm. In this way, the transparent conductive oxide nanoparticles with the above particle size and the insulating particles cooperate with each other to make the composite layer have lower lateral conductivity and effectively block the direct contact of the charge transport layers of the upper and lower sub-cells.

[0019] In any embodiment, d2 is 5 nm to 50 nm. In this way, the cooperation with the insulating particles can better reduce the lateral conductivity of the composite layer and better block the direct contact of the charge transport layers of the upper and lower sub-cells.

[0020] In any embodiment, the mass ratio of the transparent conductive oxide nanoparticles and the insulating particles in the composite layer is 1 to 5:1. In this way, the lateral conductivity of the composite layer can be better reduced, and the direct contact of the charge transport layers of the upper and lower sub-cells can be better blocked.

[0021] In any embodiment, the insulating particles include one or more of aluminum oxide particles, silicon oxide particles, zirconium oxide particles, yttrium oxide particles, polyvinyl chloride particles, polyethylene particles, polytetrafluoroethylene particles, chloroprene rubber particles, polyvinyl acetal particles, polyimide particles, polyamide-imide particles, polymaleimide particles, or polyphenylene ether particles.

[0022] In any embodiment, the insulating filler is a non-particulate insulating substance continuously filled in the gaps, and the non-particulate insulating substance includes an organic polymer film. In this way, the insulating substance can be continuously filled in the gaps, and better reduce the lateral conductivity of the composite layer and block the direct contact of the charge transport layers of the upper and lower sub-cells.

[0023] In any embodiment, the mass ratio of the transparent conductive oxide nanoparticles and the non-particulate insulating substance in the composite layer is 3 to 10:1.

[0024] In any embodiment, the thickness of the composite layer is 3 nm to 200 nm.

[0025] In any embodiment, the transparent conductive oxide nanoparticles comprise one or more of indium tin oxide particles, fluorine-doped tin oxide particles, aluminum-doped zinc oxide particles, boron-doped zinc oxide particles, indium zinc oxide particles, antimony tin oxide particles, gallium indium zinc oxide particles, or lanthanide-doped indium oxide particles, gallium zinc oxide particles, indium tungsten oxide particles.

[0026] In any embodiment, the first sub-cell comprises a first electrode, a first hole transport layer, a first perovskite layer, and a first electron transport layer, which are sequentially stacked, the first electron transport layer is disposed on a surface of the composite layer facing away from the second sub-cell.

[0027] The second sub-cell comprises a second electrode, a second electron transport layer, and a second perovskite layer, which are sequentially stacked, the second perovskite layer is disposed on a surface of the composite layer facing away from the first electron transport layer.

[0028] In any embodiment, the second sub-cell further comprises a second hole transport layer, which is disposed between the composite layer and the second perovskite layer.

[0029] A second aspect of the present application provides a preparation method of the perovskite tandem solar cell described above, comprising the following steps:

[0030] Preparation of a first sub-cell on a substrate;

[0031] Preparation of a composite layer on the first sub-cell, the composite layer comprising transparent conductive oxide nanoparticles and insulating fillers; along the spreading direction of the composite layer, at least part of the transparent conductive oxide nanoparticles has a gap with adjacent transparent conductive oxide nanoparticles; at least part of the insulating fillers are filled in the gap; and

[0032] Preparation of a second sub-cell on a surface of the composite layer facing away from the first sub-cell.

[0033] In any embodiment, the insulating fillers are insulating particles, and the preparation of the composite layer on the first sub-cell comprises the following steps:

[0034] Coating a slurry containing the transparent conductive oxide nanoparticles and the insulating particles on the first sub-cell to form a slurry layer; and

[0035] Drying and curing the slurry layer.

[0036] In any embodiment, the insulating fillers are insulating particles, and the preparation of the composite layer on the first sub-cell comprises the following steps:

[0037] coating the slurry containing the transparent conductive oxide nanoparticles on the first sub-cell, and forming a coating layer after drying and solidifying;

[0038] coating the slurry containing the insulating particles on the coating layer, and infiltrating the slurry containing the insulating particles into the coating layer; and

[0039] drying and solidifying the slurry containing the insulating particles.

[0040] In any embodiment, the insulating filler is a non-particulate insulating substance continuously filled in the gap, the non-particulate insulating substance comprising an organic polymer film; and a composite layer is prepared on the first sub-cell, comprising the following steps:

[0041] dissolving the insulating filler in a solvent and mixing with the transparent conductive oxide nanoparticles to form a mixed slurry, coating the mixed slurry on the first sub-cell to form a slurry layer; and

[0042] drying the slurry layer to form the composite layer.

[0043] A third aspect of the present application provides a photovoltaic module comprising the perovskite tandem solar cell of the first aspect of the present application, or a perovskite tandem solar cell prepared by the preparation method of the second aspect of the present application.

[0044] A fourth aspect of the present application provides a photovoltaic system comprising the photovoltaic module of the third aspect of the present application.

[0045] A fifth aspect of the present application provides an electric device comprising the photovoltaic system of the fourth aspect of the present application.

[0046] A sixth aspect of the present application provides a power generation device comprising the photovoltaic system of the fourth aspect of the present application.

[0047] Details of one or more embodiments of the present application are set forth in the description below. Other features, objects, and advantages of the present application will be apparent from the description and from the claims. DETAILED DESCRIPTION

[0048] Hereinafter, some embodiments of the perovskite tandem solar cell and the preparation method, the photovoltaic module, the system, and the electric device of the present application will be described in detail. However, there will be cases where unnecessary detailed descriptions are omitted. For example, there will be cases where detailed descriptions of matters known to those skilled in the art, repeated descriptions of substantially identical structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art.

[0049] 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 understood that ranges of 60–110 and 80–120 are also expected. 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 "a–b" 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" and "5" have been listed in this document; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, stating that a parameter is an integer ≥2 is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, 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.

[0050] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0051] 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.

[0052] In this application, unless otherwise stated, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0053] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0054] The terms “combinations of,” “any combination of,” and “any combination of” used in this article include all suitable combinations of any two or more of the listed items.

[0055] In this document, the term "suitable" as used in "suitable combination", "suitable method", "any suitable method", etc., refers to the technical solution that enables the implementation of this application.

[0056] In this document, terms such as "preferred," "better," "more suitable," and "ideal" are merely descriptions of more effective implementation methods or embodiments, and should be understood not to limit the scope of protection of this application. If multiple "preferred" terms appear in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "preferred" term shall be independent.

[0057] In this application, terms such as "further," "even more," and "particularly" are used for descriptive purposes and to indicate differences in content, but should not be construed as limiting the scope of protection of this application.

[0058] In this application, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0059] In this application, the term "room temperature" generally refers to 4℃ to 35℃, and may refer to 20℃ ± 5℃. In some embodiments of this application, room temperature refers to 20℃ to 30℃.

[0060] In this application, if the unit of a data range is only followed by the right endpoint, it indicates that the units of the left and right endpoints are the same. For example, 3h~5h or 3h~5h both indicate that the unit of the left endpoint "3" and the right endpoint "5" is h (hour).

[0061] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Furthermore, the weights mentioned in the embodiments of this application can be well-known units of mass in the chemical industry, such as μg, mg, g, and kg.

[0062] Unless otherwise specified, in this document, "alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-9 alkyl," refer to alkyl groups containing 1 to 9 carbon atoms, and each time it appears, it can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, or C9 alkyl. 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(C H3)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(CH3)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).

[0063] 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 a nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), etc. The following explanation uses O, N, and S as examples. For instance, if a carbon atom in an alkyl group that is attached to an adjacent group is replaced by a non-carbon atom such as O, N, or S, the resulting heteroalkyl group is an alkoxy (e.g., -OCH3), an amino (e.g., -NHCH3, -N(CH3)2), or a thioalkyl (e.g., -SCH3). If a carbon atom in an alkyl group that is not directly attached to an adjacent group is replaced by a non-carbon atom such as O, N, or S, the resulting heteroalkyl group is an alkoxyalkyl (e.g., -CH2CH2-O-CH3), an alkylaminoalkyl (e.g., -CH2NHCH3, -CH2N(CH3)2), or an alkylthioalkyl (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" include, for example, "C1-C9 heteroalkyl" or "C 1-9 "Heteroalkyl" refers to a heteroalkyl group containing 1 to 9 carbon atoms. Each time it appears, it can be independently C1 heteroalkyl, C2 heteroalkyl, C3 heteroalkyl, C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl or C9 heteroalkyl.

[0064] In this document, unless otherwise specified, "cycloalkyl" and "non-aromatic cycloalkyl" have the same meaning, referring to a monovalent residue formed by the loss of a hydrogen atom from a non-aromatic hydrocarbon (saturated or unsaturated) containing a ring carbon atom; that is, a monovalent linking site directly formed on the ring. Cycloalkyl derived from non-aromatic saturated hydrocarbons can be designated as saturated cycloalkyl, and cycloalkyl derived from non-aromatic unsaturated hydrocarbons can be designated as unsaturated cycloalkyl. Cycloalkyl can be monocycloalkyl, spirocycloalkyl, or bridged cycloalkyl. Phrases containing this term include, for example, "C3–C9 cycloalkyl" or "C…". 3-9 "Cycloalkyl" refers to a cycloalkyl group containing 3 to 9 carbon atoms, and each occurrence can be independently C3, C4, C5, C6, C7, C8, or C9 cycloalkyl. Suitable examples include, but are not limited to, cyclopropyl. Cyclobutyl Cyclopentyl Cyclohexyl And cycloheptyl. Additionally, "cycloalkyl" may also contain one or more double bonds; representative examples of cycloalkyl groups containing double bonds include cyclopentenyl (including, but not limited to, cyclopentenyl). ), cyclohexenyl (including but not limited to) ), cyclohexadiene (including but not limited to) ) group, cyclopentadienyl (including but not limited to) ) and cyclobutadiene (including but not limited to) ).

[0065] In this document, unless otherwise specified, "heterocyclic alkyl" refers to a cycloalkyl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, O atom, S atom, etc., and can be a saturated ring or a partially unsaturated ring. Phrases containing this term, such as "C4-C9 heterocyclic group," refer to heterocyclic groups containing 4 to 9 carbon atoms, and each occurrence can be independently C4, C5, C6, C7, C8, or C9 heteroalkyl. Suitable examples include, but are not limited to: dihydropyridyl, tetrahydropyridyl (piperidinyl), tetrahydrothiophenyl, sulfur-oxidized tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and dihydroindolyl.

[0066] In this article, unless otherwise specified, "aryl" refers to an aromatic hydrocarbon group derived from an aromatic cyclic hydrocarbon compound by losing one hydrogen atom, that is, forming a monovalent linking site directly on the ring. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl; for polycyclic species, at least one is an aromatic ring system. For example, "C6~C 10 "Aryl" refers to an aryl group containing 6 to 10 carbon atoms. Each time it appears, it can be independently C6 aryl, C8 aryl, C9 aryl, or C6 aryl. 10 Aryl groups. For example, "C6~C 20 "Aryl" refers to an aryl group containing 6 to 20 carbon atoms. Each time it appears, it can independently be, but is not limited to, C6 aryl aryl (e.g., phenyl), C6 aryl aryl (e.g., benzocyclobutenyl), C8 aryl (e.g., phenylpropylcyclobutenyl), C9 aryl (e.g., indene), C6 aryl aryl, C8 aryl aryl (e.g., phenylpropylcyclobutenyl), C9 aryl aryl (e.g., indene), C9 aryl aryl, ... 10 Aryl (such as naphthyl), C 12 Aryl (such as acenaphthene, biphenyl), C 13 Aryl (such as fluorene), C 14 Aryl (such as anthracene, phenanthrene), C 18 Aryl (such as phenylene) or C 20 Aryl groups (such as dinaphthalene-based phenylene). Examples of suitable aromatic cyclic hydrocarbons include, but are not limited to: benzene, phenylcyclobutene, biphenyl, indene, naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, triphenylene, dinaphthalene-based phenylene and their derivatives.

[0067] Unless otherwise specified, "heteroaryl" in this text refers to an aromatic heterocyclic group. It can be a monovalent group formed by replacing at least one carbon atom with a non-carbon atom on an aryl base, or a monovalent group formed by replacing at least one carbon atom with a non-carbon atom on a cyclopentadienyl base. The non-carbon atom can be, but is not limited to, nitrogen (N), oxygen (O), sulfur (S), etc. For example, "C1~C..." 10 "Heteroaryl" refers to a heteroaryl group containing 1 to 10 carbon atoms. Each occurrence can be independently of a C1 heteroaryl (e.g., tetrazolyl), C2 heteroaryl (e.g., triazolyl, oxadiazolyl), C3 heteroaryl (e.g., imidazolyl), C4 heteroaryl (e.g., furanyl), C5 heteroaryl (e.g., pyridinyl), C6 heteroaryl, C7 heteroaryl (e.g., benzimidazole), C8 heteroaryl (e.g., indoleyl), C9 heteroaryl (e.g., quinolinyl), or C... 10 Heteroaryl groups (such as pyrrolodipyridyl). Also, for example, "C3-C..." 20 "Heteroaryl" refers to a heteroaryl group containing 3 to 20 carbon atoms. Each occurrence can be independently of, but is not limited to, C2-, C3-, C4-, C5-, C6-, C8-, C9-, and C2-. 10 heteroaryl, C 12 heteroaryl, C 13 heteroaryl, C 14 heteroaryl, C 18 heteroaryl or C 20 Heteroaryl groups. Suitable examples include, but are not limited to, heteroaryl groups derived from the following heteroaryl rings (the number of carbon atoms is indicated in parentheses): furan (C4), benzofuran (C8), thiophene (C4), benzothiophene (C8), pyrrole (C4), pyrazole (C3), triazole (C2), imidazole (C3), oxazole (C3), oxadiazole (C2), thiazole (C3), tetrazolium (C1), indole (C8), carbazole (C1), and so on. 12 ), pyrrolopyrazole (C5), pyrrolopyrazole (C6), thienopyrazole (C6), thienothienopyrazole (C6), furanopyrazole (C6), furanofuran (C6), thienofuran (C6), thienopyridine (C7), furanopyridine (C7), benzoxazole (C7), benzoisoxazole (C7), benzothiazole (C7), benzoisothiazole (C7), benzoimidazolium (C7), pyridine (C5), pyrazine (C4), pyridazine (C4), pyrimidine (C4), triazine (C3), quinoline (C9), isoquinoline (C9), diazonaphthalene (C8, such as o-diazonaphthalene), quinoxaline (C8), phenanthridine (C5), pyrazine (C6), pyrazine (C7), pyrazine (C8), phenanthridine (C8), pyrazine (C9 ... 13 ), Prididine (C 11 ), quinazoline (C8) and quinazoline ketone (C8).

[0068] Unless otherwise specified, "alkylene" refers to a hydrocarbon group with two monovalent centers, derived from an alkane by removing two hydrogen atoms (or derived from an alkyl group by removing one more hydrogen atom), and can be a saturated branched alkyl or a saturated straight-chain alkyl. For example, "C1 to C9 alkylene" refers to an alkyl moiety containing 1 to 9 carbon atoms, and each occurrence can be independently C1, C2, C3, C4, C5, C6, C7, C8, 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-).

[0069] Unless otherwise specified, "halogen" or "halogen group" in this article refers to F, Cl, Br or I.

[0070] Unless otherwise specified, "amino" in this article can refer to primary amino (-NH2), secondary amino (>NH), tertiary amino (>N-), or quaternary amino (>N). + <).

[0071] In this document, unless otherwise specified, hydroxyl group is -OH, carboxyl group is -COOH, cyano group is -CN, hydrazine group is -NHNH2, sulfinic acid group is -S(=O)OH, hypophosphite group is (*-)2P(=O)OH, sulfonic acid group is -S(=O)2OH, phosphate group is (*-)P(=O)(OH)2, and borate group is (*-)B(OH)2. Specifically, the * in hypophosphite group indicates attachment to a carbon atom or H, with at least one attached to a carbon atom; the * in phosphite group indicates attachment to a carbon atom; and the * in borate group indicates attachment to a carbon atom.

[0072] In some embodiments of this application, a perovskite tandem solar cell is provided, which includes a first sub-cell, a composite layer, and a second sub-cell stacked sequentially; wherein, the composite layer includes transparent conductive oxide nanoparticles and an insulating filler; along the spreading direction of the composite layer, at least a portion of the transparent conductive oxide nanoparticles have gaps between adjacent transparent conductive oxide nanoparticles; at least a portion of the insulating filler fills the gaps.

[0073] In traditional perovskite tandem solar cells, when transparent conductive oxide (TCO) is used as the composite layer material, the composite layer is usually prepared by physical vapor deposition (PVD). Although the transparent conductive oxide composite layer prepared by this method has good longitudinal conductivity, which enables electrons and holes to recombine well, its lateral conductivity is also very good, which can easily cause serious lateral leakage in the cell, resulting in a decrease in the fill factor of the cell.

[0074] In the perovskite tandem solar cell of this application, transparent conductive oxide nanoparticles are used as the material of the composite layer. Due to their particle morphology, the transparent conductive oxide nanoparticles are not continuously distributed during the composite layer fabrication process; in the spreading direction of the composite layer, there are certain gaps between some transparent conductive oxide nanoparticles and their adjacent transparent conductive oxide nanoparticles, making the composite layer discontinuous in its spreading direction. This effectively reduces the lateral conductivity of the composite layer, which is beneficial to improving the fill factor of the perovskite tandem solar cell. Furthermore, by using transparent conductive oxide nanoparticles as the material of the composite layer, light diffracts through the gaps between the particles when passing through the composite layer, which can reduce parasitic absorption.

[0075] However, due to the gaps between transparent conductive oxide nanoparticles, when the charge transport layer (such as the hole transport layer) of the upper sub-cell is prepared on the composite layer, the charge transport layer material may penetrate into the gap and come into contact with the charge transport layer (such as the electron transport layer) of the lower sub-cell, resulting in a reverse electric field and thus reducing the open-circuit voltage of the perovskite tandem solar cell.

[0076] To address this issue, this application introduces an insulating filler into the composite layer, which fills the gaps formed by the transparent conductive oxide nanoparticles. This insulating filler not only further reduces the probability of contact between the transparent conductive oxide nanoparticles, resulting in lower lateral conductivity of the composite layer and improved fill factor of the perovskite tandem solar cell, but also blocks direct contact between the charge transport layers of the upper and lower sub-cells, reducing the probability of generating a reverse electric field and thus improving the open-circuit voltage of the perovskite tandem solar cell. Therefore, the perovskite tandem solar cell of this application exhibits a higher open-circuit voltage and fill factor, resulting in higher photoelectric conversion efficiency.

[0077] In some embodiments, the mass ratio of transparent conductive oxide nanoparticles to insulating filler in the composite layer is 0.1 to 20:1. By controlling the mass ratio of transparent conductive oxide nanoparticles to insulating filler in the composite layer within the above range, the insulating filler can better fill the gaps between the transparent conductive oxide nanoparticles, giving the composite layer a low lateral conductivity and effectively preventing direct contact between the charge transport layers of the upper and lower sub-cells.

[0078] It is understandable that the mass ratio of transparent conductive oxide nanoparticles to insulating filler in the composite layer can be 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, or any ratio within the range formed by any two of the above ratios.

[0079] In some embodiments, the insulating filler is insulating particles. By using insulating particles as the insulating filler, these particles fill the gaps between the transparent conductive oxide nanoparticles, which not only serve to fill the gaps and prevent direct contact between the charge transport layers of the upper and lower sub-cells, but also allow for better dispersion of the transparent conductive oxide nanoparticles when the composite layer is prepared using a slurry coating method, further reducing the lateral conductivity of the composite layer.

[0080] It should be noted that the insulating filler does not necessarily have to be particulate. For example, it can also be an insulating material that is filled in the gaps between transparent conductive oxide nanoparticles in the form of a slurry, and then cured to form a non-particulate insulating filler. This non-particulate insulating material can continuously fill the gaps. As an example, the aforementioned non-particulate insulating material can be an insulating filler formed by cross-linking and curing organic polymer monomers and corresponding cross-linking curing agents.

[0081] In some embodiments, the particle size of the insulating particles is d1, and the particle size of the transparent conductive oxide nanoparticles is d2, with 0 ≤ |d1-d2| < 200. By setting the absolute value of the difference between the particle size d1 of the insulating particles and the particle size d2 of the transparent conductive oxide nanoparticles within the above range, the insulating particles can better fill the gaps formed by the transparent conductive oxide nanoparticles, effectively dispersing the transparent conductive oxide nanoparticles, effectively reducing the lateral conductivity of the composite layer, and preventing direct contact between the charge transport layers of the upper and lower sub-cells.

[0082] It should be noted that the particle size of insulating particles and transparent conductive oxide nanoparticles refers to the average particle size obtained by scanning electron microscopy (SEM). These particles can be primary or secondary particles.

[0083] Specifically, in some embodiments, d1 / d2 is 1:1 to 1:20. This allows the insulating particles to have a diameter equal to or smaller than the transparent conductive oxide nanoparticles, enabling the insulating particles to better fill the gaps formed by the transparent conductive oxide nanoparticles. It is understood that d1 / d2 can be 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, or any ratio within the range formed by any two of the above ratios.

[0084] In some embodiments, the particle size d1 of the insulating particles is 1 nm to 150 nm. Insulating particles with the above particle size can effectively fill the gaps formed by the transparent conductive oxide nanoparticles. It is understood that the particle size d1 of the insulating particles can be 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, or any value within the range formed by any two of the above values.

[0085] Furthermore, the particle size d1 of the insulating particles is 2nm to 40nm. By controlling the particle size of the insulating particles within the above range, the insulating particles can better fill the gaps formed by the transparent conductive oxide nanoparticles, thereby better reducing the lateral conductivity of the composite layer and preventing direct contact between the charge transport layers of the upper and lower sub-cells.

[0086] In some embodiments, the particle size d2 of the transparent conductive oxide nanoparticles is 1 nm to 200 nm. The use of transparent conductive oxide nanoparticles with the aforementioned particle size in combination with insulating particles enables the composite layer to have a low lateral conductivity and effectively prevents direct contact between the charge transport layers of the upper and lower sub-cells.

[0087] Understandably, the particle size d2 of the transparent conductive oxide nanoparticles can be 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 195 nm, 200 nm, or any value within the range formed by any two of the above values.

[0088] Furthermore, in some embodiments, the particle size d2 of the transparent conductive oxide nanoparticles is 5 nm to 50 nm. The use of transparent conductive oxide nanoparticles with the aforementioned particle size, in conjunction with insulating particles, can better reduce the lateral conductivity of the composite layer and better prevent direct contact between the charge transport layers of the upper and lower sub-cells.

[0089] In some embodiments, the mass ratio of transparent conductive oxide nanoparticles to insulating particles in the composite layer is 1 to 5:1. When the composite layer uses transparent conductive oxide nanoparticles and insulating particles, controlling the mass ratio of transparent conductive oxide nanoparticles to insulating particles within the above range can better reduce the lateral conductivity of the composite layer and better prevent direct contact between the charge transport layers of the upper and lower sub-cells.

[0090] In some embodiments, the insulating particles include one or more of the following: alumina (Al₂O₃) particles, silicon oxide (SiO₂) particles, zirconium oxide (ZrO₂) particles, yttrium oxide (Y₂O₃) particles, polyvinyl chloride (PVC) particles, polyethylene (PE) particles, polytetrafluoroethylene (PTFE) particles, chloroprene rubber (CR) particles, polyvinyl acetal particles, polyimide (PI) particles, polyamide-imide (PAI) particles, polymaleimide particles, or polydiphenyl ether particles. These insulating particles possess good insulation properties, and when filled into the gaps formed by the transparent conductive oxide nanoparticles, they can effectively reduce the lateral conductivity of the composite layer.

[0091] In some embodiments, when the insulating filler in the composite layer is a non-particulate insulating material formed by filling the gaps between transparent conductive oxide nanoparticles in the form of a slurry and curing it; the mass ratio of transparent conductive oxide nanoparticles to insulating filler can be 3 to 10:1.

[0092] In some embodiments, the thickness of the composite layer is 3 nm to 200 nm. Setting the thickness within this range allows for efficient recombination of electrons and holes within the composite layer, resulting in a higher light absorption rate for the battery. Furthermore, the thickness of the composite layer can be matched to the particle size d2 of the transparent conductive oxide nanoparticles. Specifically, when the particle size of the transparent conductive oxide nanoparticles is large, the thickness of the composite layer can be relatively thick; when the particle size of the transparent conductive oxide nanoparticles is small, the thickness of the composite layer can be relatively thin.

[0093] It is understood that the thickness of the composite layer can be 3nm, 5nm, 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, or any value within the range formed by any two of the above values.

[0094] In some embodiments, the transparent conductive oxide nanoparticles include one or more of indium tin oxide (ITO) particles, fluorine-doped tin oxide (FTO) particles, aluminum-doped zinc oxide (AZO) particles, boron-doped zinc oxide (BZO) particles, indium zinc oxide (IZO) particles, antimony tin oxide (ATO) particles, gallium indium zinc oxide (IGZO) particles, or lanthanide-doped indium oxide particles, gallium zinc oxide particles, and indium tungsten oxide particles. Using the above-mentioned TCO materials as transparent conductive oxide nanoparticles enables the composite layer to have a good electron / hole recombination rate and good light transmittance. In some specific examples, indium tin oxide particles are used as the transparent conductive oxide nanoparticles.

[0095] In some embodiments, the first sub-cell includes a first electrode, a first hole transport layer, a first perovskite layer, and a first electron transport layer stacked sequentially. The first electron transport layer is disposed on the surface of the composite layer facing away from the second sub-cell. The second sub-cell includes a second electrode, a second electron transport layer, and a second perovskite layer stacked sequentially. The second perovskite layer is disposed on the surface of the composite layer facing away from the first electron transport layer.

[0096] That is, in the above embodiments, the perovskite tandem solar cell includes a first electrode, a first charge transport layer, a first perovskite layer, a first electron transport layer, a composite layer, a second perovskite layer, a second electron transport layer, and a second electrode, which are sequentially stacked. In this perovskite tandem solar cell, the composite layer can replace the hole transport layer of the second sub-cell, playing the role of transporting holes and recombinating charge carriers. Both the first and second sub-cells in this perovskite tandem solar cell are perovskite solar cells, and this perovskite tandem solar cell is a fully perovskite tandem solar cell.

[0097] Furthermore, the perovskite materials of the first and second perovskite layers in the aforementioned perovskite tandem solar cells have different band gaps. Specifically, one perovskite layer uses a wide band gap perovskite material, while the other uses a narrow band gap perovskite material. In some specific examples, the band gap of the wide band gap perovskite material is 1.6 eV to 2.3 eV; the band gap of the narrow band gap perovskite material is 1.1 eV to 1.4 eV.

[0098] In some embodiments, the second sub-cell further includes a second hole transport layer disposed between the composite layer and the second perovskite layer. That is, the second hole transport layer can also be combined with the composite layer in the second sub-cell, which can further improve hole transport performance.

[0099] In some embodiments, the materials of the first electrode and the second electrode each independently include one or more of organic conductive materials, inorganic conductive materials, or organic-inorganic mixed conductive materials. Optionally, they include one or more of transparent conductive oxides, carbon, metals and their alloys; more preferably, they include at least one of indium tin oxide (ITO), lanthanide-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), zinc aluminum oxide (AZO), indium zinc oxide (IZO), zinc gallium oxide (GZO), indium tungsten oxide (IWO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W and their alloys, graphite, graphene, and carbon nanotubes; optionally, they include at least one of Ag, Cu, C, Au, Al, ITO, AZO, BZO, or IZO; further optionally, they include at least one of Cu, Ag, and Au.

[0100] In some embodiments, the first and second perovskite layers are perovskite-type metal halides with chemical formulas including ABX3 or A2CDX6. Wherein, A represents a monovalent inorganic cation, organic cation, or mixed organic-inorganic cation; B represents a divalent inorganic cation, organic cation, or mixed organic-inorganic cation; C represents a monovalent inorganic cation, organic cation, or mixed organic-inorganic cation; D represents a trivalent inorganic cation, organic cation, or mixed organic-inorganic cation; and X represents a monovalent inorganic anion, organic anion, or mixed organic-inorganic anion.

[0101] A represents a monovalent inorganic cation; optionally, A includes Li. + Na + K + 、Rb + and Cs + One or more of the following; A represents an organic cation, optionally A includes at least one selected from methylamino, ethylamino, propylamino, butylamino, pentamino, hexamino, formamidinyl, and imidazolyl, more preferably A includes an organic amine ion and Cs + One or more of the following. B includes divalent cations, and optionally, B includes divalent cations of one or more of the following elements: lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, and europium.

[0102] C represents a monovalent inorganic cation; optionally, C includes Cs. + Ag + K + and Rb + One or more of the following. D represents a trivalent metal cation; optionally, D includes Bi. 3+ Ni 3+ Fe 3+ Sb 3+ In 3+ and Cu 3+ One or more of them, more preferably, D includes In 3+ Bi 3+ Sb 3+ One or more of the following. X represents a halide ion, and optionally, X includes F. - Cl - ,Br - and I - One or more of them, more preferably, X includes Cl - ,Br - and I - One or more of them.

[0103] In some embodiments, the hole transport material in the hole transport layer includes, but is not limited to, 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene, methoxytriphenylamine-fluoroformamidinium, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, poly3-hexylthiophene, triphenylamine with a triphenylene core, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirodifluorene, polythiophene, phosphate monomers, carbazole monomers, sulfonic acid monomers, triphenylamine monomers, aromatic monomers, metal oxides (which may be referred to as the first metal oxide), cuprous iodide, or cuprous thiocyanate, or one or more of these. The metal element in the first metal oxide may include one or more of Ni, Mo, or Cu.

[0104] In some embodiments, the electron transport material in the electron transport layer includes, but is not limited to, one or more of the following materials and their derivatives: imide compounds, quinone compounds, fullerenes and their derivatives, methoxytriphenylamine-fluoroformamidine (OMeTPA-FA), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), poly3-hexylthiophene (P3HT), triphenylamine with a triphenylene core (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobisfluorene (CzPAF-SBF), polythiophene, metal oxides (which may be referred to as second metal oxides), silicon oxide (SiO2), strontium titanate (SrTiO3), calcium titanate, lithium fluoride, calcium fluoride, cuprous thiocyanate (CuSCN), etc. The metal element in the second metal oxide may include one or more of Mg, Ni, Cd, Zn, In, Pb, Mo, W, Sb, Bi, Cu, Hg, Ti, Ag, Mn, Fe, V, Sn, Zr, Sr, Ga, or Cr.

[0105] Some embodiments of this application provide a method for fabricating the above-mentioned perovskite tandem solar cell, the method comprising the following steps S100 to S300:

[0106] Step S100: Prepare the first sub-cell on the substrate.

[0107] In some embodiments, the first sub-cell is prepared as follows:

[0108] Using glass as a substrate, a conductive material layer is first prepared on the glass substrate to form a first electrode. The glass substrate with the first electrode is then cleaned sequentially with acetone, alcohol, and deionized water, and dried for later use. A hole transport layer material is added to a solvent and stirred. The solution is then spin-coated onto the first electrode and transferred to a hot stage for annealing to form a first hole transport layer. A perovskite precursor solution is spin-coated onto the first hole transport layer and then transferred to a hot stage for annealing to form a first perovskite layer. Finally, an electron transport layer material is prepared on the first perovskite layer to form a first electron transport layer.

[0109] Step S200: Prepare a composite layer on the first sub-cell.

[0110] The composite layer comprises transparent conductive oxide nanoparticles and an insulating filler; along the spreading direction of the composite layer, at least some of the transparent conductive oxide nanoparticles have gaps between adjacent transparent conductive oxide nanoparticles; the insulating filler fills the gaps.

[0111] In some embodiments, the composite layer is prepared as follows: transparent conductive oxide nanoparticles and insulating particles are mixed with a solvent to obtain a mixed slurry; the mixed slurry is spin-coated onto the first electron transport layer of the first sub-cell, and then annealed to form the composite layer. This method enables the composite layer to be formed in one step, resulting in a uniform thickness distribution.

[0112] In some embodiments, the composite layer is prepared as follows: a slurry containing transparent conductive oxide nanoparticles is coated onto the first electron transport layer of the first sub-cell, and the slurry is annealed to dry and solidify to form a coating; then, a slurry containing insulating particles is coated onto the coating, allowing the insulating particles to penetrate into the coating, and the slurry is annealed to dry and solidify, thereby forming the composite layer. This two-step method of forming the composite layer allows the insulating particles to better fill the gaps between the transparent conductive oxide nanoparticles.

[0113] In some embodiments, the composite layer is prepared as follows: an organic insulating filler (organic polymer) is dissolved in a solvent and mixed with transparent conductive oxide nanoparticles to form a mixed slurry; the mixed slurry is spin-coated onto the first electron transport layer of the first sub-cell, and then annealed to form the composite layer. Using the above method, an organic polymer film continuously filling the gaps can be formed.

[0114] It should be noted that after the mixed slurry is spin-coated onto the first electron transport layer, the transparent conductive oxide nanoparticles can contact each other along the thickness direction of the slurry coating due to their own gravity. After the composite layer is formed, it has high conductivity in the longitudinal direction (thickness direction), that is, the composite layer has high longitudinal conductivity, which enables electrons / holes to recombine well in the composite layer.

[0115] Step S300: Prepare a second sub-cell on the surface of the composite layer opposite to the first sub-cell.

[0116] In some embodiments, the second sub-cell is prepared as follows:

[0117] Hole transport layer material is added to a solvent and stirred. The solution is then spin-coated onto a composite layer and transferred to a hot plate for annealing to form a second hole transport layer. A perovskite precursor solution is spin-coated onto the second hole transport layer and then transferred to a hot plate for annealing to form a second perovskite layer. An electron transport layer material is then prepared on the second perovskite layer to form a second electron transport layer. Finally, an electrode material is prepared on the second electron transport layer to form a second electrode.

[0118] In some embodiments of this application, a photovoltaic module is also provided, which includes the perovskite tandem solar cell described above. The photovoltaic module of this application, by employing the perovskite tandem solar cell described above, exhibits higher open-circuit voltage, fill factor, and photoelectric conversion efficiency.

[0119] The aforementioned photovoltaic module includes one or more perovskite tandem solar cells, which can be selected according to specific application scenarios; furthermore, the aforementioned photovoltaic module includes multiple perovskite tandem solar cells, which are connected in series or in parallel to form a solar cell.

[0120] In some embodiments, the photovoltaic module further includes a photovoltaic glass layer, an adhesive layer, and a backsheet.

[0121] The solar cell has an adhesive layer on each of its two surfaces. A backsheet is provided on the surface of one adhesive layer away from the solar cell, and a photovoltaic glass layer is provided on the surface of the other adhesive layer away from the solar cell.

[0122] The photovoltaic glass layer and backsheet are used to protect the perovskite tandem solar cells, and they have the functions of sealing, insulation and waterproofing; the adhesive layer plays the role of bonding the photovoltaic glass layer to the solar cells and bonding the backsheet to the solar cells.

[0123] Optionally, the photovoltaic glass layer is made of tempered glass, the backsheet is made of TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the adhesive layer is made of EVA (polyethylene-polyvinyl acetate copolymer).

[0124] Furthermore, the aforementioned photovoltaic modules also include junction boxes and outer frames.

[0125] Junction boxes are used to protect the entire photovoltaic module's power generation system. They are essentially a current transfer station. When a cell short-circuits, the junction box will automatically disconnect the short-circuited cell string.

[0126] The outer frame serves to support and protect the entire photovoltaic module. The frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0127] Furthermore, silicone is used to bond and seal the connections between the frame and other parts of the photovoltaic module. The photovoltaic module can convert solar energy into electrical energy, which can then be stored in batteries or used to power loads.

[0128] In some embodiments, the photovoltaic module is a solar panel.

[0129] In some embodiments of this application, a photovoltaic system is also provided, which includes the photovoltaic modules described above.

[0130] The photovoltaic system utilizes the perovskite tandem solar cells in the aforementioned photovoltaic modules to directly convert solar radiation energy into electrical energy, exhibiting high efficiency and good stability; furthermore, the aforementioned photovoltaic system is a photovoltaic power generation system.

[0131] Photovoltaic modules are the core component of a photovoltaic power generation system. The aforementioned photovoltaic system includes one or more photovoltaic modules, which can be selected according to specific application scenarios. Furthermore, when the aforementioned photovoltaic system includes multiple photovoltaic modules, the multiple photovoltaic modules form a photovoltaic array.

[0132] The aforementioned photovoltaic system can be a stand-alone photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0133] An independent photovoltaic (PV) power generation system includes a PV array, battery bank, charge controller, power electronic converter (inverter), and load. Its working principle is that solar radiation energy is first converted into electrical energy by the PV array, then converted by the power electronic converter to supply power to the load. Simultaneously, excess electrical energy is stored as chemical energy in an energy storage device after passing through the charge controller. Thus, when sunlight is insufficient, the energy stored in the battery can be converted into 220V, 50Hz AC power by the power electronic inverter, filter, and power frequency transformer to supply AC loads.

[0134] A grid-connected photovoltaic (PV) power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and system monitoring. Its working principle is that solar radiation energy is converted by the photovoltaic array, then converted into high-voltage DC by a high-frequency DC converter, and finally inverted by the power electronic inverter to output a sinusoidal alternating current to the grid that is in phase with the grid voltage.

[0135] The two photovoltaic power generation systems mentioned above each have their own characteristics and can be selected according to the specific application scenario.

[0136] In some embodiments of this application, an electrical device is also provided, which includes the photovoltaic system described above.

[0137] In some embodiments, the power-consuming device is a common device including the perovskite tandem solar cell of this application, such as in the fields of communications, transportation, industry and agriculture, and lighting. Examples of power-consuming devices include satellites, communication equipment, traffic lights, lighthouses, wireless telephone booths, monitoring equipment in the oil drilling field, power systems, camping lights, electric vehicles, electronic device chargers, building facades, etc.

[0138] In some embodiments of this application, a power generation device is also provided, which includes the photovoltaic system described above.

[0139] 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.

[0140] Example 1:

[0141] A method for fabricating the perovskite tandem solar cell of this application comprises the following steps:

[0142] (1) Preparation of the first electrode

[0143] Glass is used as the substrate. A layer of conductive material, indium tin oxide (ITO), is first prepared on the glass substrate to form the first electrode. The glass substrate with the first electrode is then cleaned sequentially with acetone, alcohol, and deionized water, and dried for later use.

[0144] (2) Preparation of the first hole transport layer

[0145] Hole transport layer material [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphoric acid (MeO-4PACz) was added to ethanol solvent and stirred. The ethanol solution of MeO-4PACz was spin-coated onto the first electrode at a spin speed of 4000 rpm for 30 s. Then, it was transferred to a hot plate and annealed at 100 °C for 10 min to form the first hole transport layer.

[0146] (3) Preparation of the first perovskite layer

[0147] 3 mg of FAI, 59 mg of FABr, 46 mg of CsI, 25 mg of CsBr, 428 mg of PbI2 and 209 mg of PbBr2 were added to 1 mL of a mixed solvent of DMF and DMSO (DMF to DMSO volume ratio of 3:1). The mixture was stirred at 600 rpm for 8 h on a magnetic stirrer and then filtered to obtain a perovskite precursor solution. 100 μL of the perovskite precursor solution was spin-coated onto the first hole transport layer (first spin-coated at 2000 rpm and 200 rpm / s for 10 s, then spin-coated at 4000 rpm and 1000 rpm / s for 25 s); then 200 μL of chlorobenzene was added dropwise onto the spin-coated perovskite precursor solution; then the perovskite precursor solution was spin-coated again at 4000 rpm for 15 s, and then transferred to a hot plate and annealed at 100°C for 15 min to form the first perovskite layer.

[0148] (4) Fabrication of the first electron transport layer

[0149] A SnO2 layer with a thickness of 20 nm was prepared on the first perovskite layer using an atomic layer deposition (ALD) apparatus to form the first electron transport layer.

[0150] (5) Preparation of composite layer

[0151] ITO nanoparticles and Al2O3 nanoparticles were dispersed in isopropanol to obtain a mixed slurry with a total mass concentration of 5%. The particle size d2 of the ITO nanoparticles in the mixed slurry was 30 nm, and the particle size d1 of the Al2O3 nanoparticles was 10 nm, with a d1 / d2 ratio of approximately 0.33. The mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry was 4:1. The mixed slurry was spin-coated onto the first electron transport layer and then annealed at 100°C for 10 min to form a composite layer with a thickness of 100 nm.

[0152] (6) Preparation of the second hole transport layer

[0153] The hole transport layer material poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was spin-coated onto the above composite layer at a spin speed of 4000 rpm for 30 s. Then, it was transferred to a hot plate and annealed at 150°C for 10 min to form the second hole transport layer.

[0154] (7) Preparation of the second perovskite layer

[0155] 2 mg of CH(NH2)2I, 85 mg of CH3NH2I, 4 mg of PbI2, 335 mg of SnI2, and 0.5 mg of MeO-4PACz were added to 1 mL of a mixed solvent of DMF and DMSO (DMF to DMSO volume ratio of 3:1). The mixture was stirred at 600 rpm for 2 h on a magnetic stirrer and then filtered to obtain a perovskite precursor solution. 100 μL of the perovskite precursor solution was spin-coated onto the second hole transport layer (first spin-coated at 1000 rpm and 200 rpm / s for 10 s, then spin-coated at 3000 rpm and 1000 rpm / s for 20 s); then 350 μL of ethyl acetate was added dropwise onto the spin-coated perovskite precursor solution; then the perovskite precursor solution was spin-coated again at 4000 rpm for 20 s, and then transferred to a hot plate and annealed at 100°C for 10 min to form the second perovskite layer.

[0156] (8) Fabrication of the second electron transport layer

[0157] A 10 nm thick copper bath (BCP) layer is deposited on the aforementioned second perovskite layer to form the second electron transport layer.

[0158] (9) Preparation of the second electrode

[0159] A 100 nm thick layer of metallic copper (Cu) is deposited on the aforementioned second electron transport layer to form the second electrode.

[0160] Example 2:

[0161] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 0.1:1.

[0162] Example 3:

[0163] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 0.5:1.

[0164] Example 4:

[0165] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 1:1.

[0166] Example 5:

[0167] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 2:1.

[0168] Example 6:

[0169] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 3:1.

[0170] Example 7:

[0171] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 5:1.

[0172] Example 8:

[0173] This embodiment is basically the same as that of embodiment 1, except that in step (5), the mass ratio of ITO nanoparticles to Al2O3 nanoparticles in the mixed slurry is 20:1.

[0174] Example 9:

[0175] This embodiment is basically the same as Embodiment 1, except that the preparation method of the composite layer in step (5) is different. In this embodiment, a 1% mass concentration of ITO nanoparticles in isopropanol solution is first spin-coated onto the first electron transport layer, and the coating is dried by annealing on a hot plate. Then, a 0.5% mass concentration of alumina nanoparticles in isopropanol solution is spin-coated, and then annealed at 100°C for 10 min.

[0176] Example 10:

[0177] This embodiment is basically the same as that of embodiment 1, except that in step (5), the particle size d2 of the ITO nanoparticles in the mixed slurry is 10 nm, the particle size d1 of the Al2O3 nanoparticles is 2 nm, and the d1 / d2 ratio is 0.2.

[0178] Example 11:

[0179] This embodiment is basically the same as that of embodiment 1, except that in step (5), the particle size d2 of the ITO nanoparticles in the mixed slurry is 100 nm, the particle size d1 of the Al2O3 nanoparticles is 50 nm, and the d1 / d2 ratio is 0.5.

[0180] Example 12:

[0181] This embodiment is basically the same as that of embodiment 1, except that: in step (5), the particle size d2 of the ITO nanoparticles in the mixed slurry is 200nm, d1 / d2 is 0.05, and the thickness of the composite layer is 200nm.

[0182] Example 13:

[0183] This embodiment is basically the same as that of embodiment 1, except that in step (5), the particle size d2 of the ITO nanoparticles in the mixed slurry is 5nm, the particle size d1 of the Al2O3 nanoparticles is 1nm, and the d1 / d2 ratio is 0.2.

[0184] Example 14:

[0185] This embodiment is basically the same as that of embodiment 1, except that in step (5), the particle size d2 of the ITO nanoparticles in the mixed slurry is 50 nm, the particle size d1 of the Al2O3 nanoparticles is 40 nm, and the d1 / d2 ratio is 0.8.

[0186] Example 15:

[0187] This embodiment is basically the same as embodiment 1, except that the thickness of the composite layer in step (5) is 3nm.

[0188] Example 16:

[0189] This embodiment is basically the same as that of embodiment 1, except that the transparent conductive oxide nanoparticles in step (5) are FTO nanoparticles.

[0190] Example 17:

[0191] This embodiment is basically the same as embodiment 1, except that the insulating particles in step (5) are polyvinyl chloride nanoparticles.

[0192] Example 18:

[0193] This embodiment is basically the same as Embodiment 1, except that in step (5), the composite layer is prepared using the following method:

[0194] Polystyrene was dissolved in IPA (isopropanol) solvent and mixed with ITO nanoparticle dispersion to obtain a mixed slurry. The mixed slurry was then spin-coated onto the first electron transport layer and annealed at 100°C for 10 min to form a composite layer with a thickness of 100 nm. The mass ratio of ITO nanoparticles to polystyrene in the composite layer was 10:1.

[0195] Example 19:

[0196] This embodiment is basically the same as that of embodiment 18, except that in step (5), the mass ratio of ITO nanoparticles to polystyrene in the composite layer is 3:1.

[0197] Comparative Example 1:

[0198] This comparative example is basically the same as Example 1, except that in step (5), a composite layer is formed by physical vapor deposition, and the composite layer does not contain insulating filler.

[0199] Comparative Example 2:

[0200] This comparative example is basically the same as Example 1, except that Al2O3 nanoparticles are not added to the mixed slurry in step (5).

[0201] Comparative Example 3:

[0202] This comparative example is basically the same as Example 1, except that the preparation method of the composite layer in step (5) is different. In this comparative example, a layer of polyvinyl alcohol (PVA) is first spin-coated on the first electron transport layer, and then exposed to an environment with 50% humidity for 10 min. Then, a layer of ITO is sputtered, and then PVA is removed by washing with ethanol to obtain a discontinuous ITO film. An isopropanol solution of alumina nanoparticles with a concentration of 1 mg / mL is spin-coated on the above discontinuous ITO film, and then annealed at 100°C for 5 min.

[0203] Test method:

[0204] (1) Test of the mass ratio of TCO particles to insulating filler

[0205] The elemental content of the insulating filler and the TCO composite layer can be tested to obtain their content ratio.

[0206] (2) Particle size testing of TCO particles and insulating particles

[0207] The average particle size was measured using SEM.

[0208] (3) Performance testing of perovskite tandem solar cells

[0209] Using a solar simulator under standard test conditions (total irradiance 100 mW / cm²) 2 The photoelectric conversion efficiency of a perovskite tandem solar cell was tested at a cell temperature of 25℃ and a spectral distribution of AM1.5G. Readings were recorded using a Keithley 2400 series digital multimeter. The photoelectric conversion efficiency of the perovskite tandem solar cell was calculated as follows:

[0210] PCE = P OUT / P OPT

[0211] =VOC ×J SC ×(V MPP ×J MPP ) / (V OC ×J SC ) / P OPT

[0212] =V OC ×J SC ×FF / P OPT

[0213] Among them, P OUT P OPT V MPP (V), J MPP (mA / cm 2 V OC (V), J SC (mA / cm 2 ) and FF represent the operating output power, incident light power, maximum power point voltage, maximum power point current, open circuit voltage, short circuit current, and fill factor of the perovskite tandem solar cell, respectively. OUT P OPT V MPP (V), J MPP (mA / cm 2 V OC (V) and J SC (mA / cm 2 (Obtained using a digital multimeter.)

[0214] The materials, parameters, and performance test results of the perovskite tandem solar cells in the above embodiments and comparative examples are shown in Tables 1, 2, and 3.

[0215] Table 1

[0216] Table 2

[0217] Table 3

[0218] As can be seen from the above data, the perovskite tandem solar cells of various embodiments of this application have high open-circuit voltage, fill factor and conversion efficiency.

[0219] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0220] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A perovskite tandem solar cell, comprising a first sub-cell, a composite layer, and a second sub-cell arranged sequentially on a tandem basis; The composite layer comprises transparent conductive oxide nanoparticles and an insulating filler; Along the spreading direction of the composite layer, at least a portion of the transparent conductive oxide nanoparticles have gaps between adjacent transparent conductive oxide nanoparticles; at least a portion of the insulating filler fills the gaps.

2. The perovskite tandem solar cell according to claim 1, wherein, The mass ratio of the transparent conductive oxide nanoparticles to the insulating filler in the composite layer is 0.1 to 20:

1.

3. The perovskite tandem solar cell according to claim 1 or 2, wherein, The insulating filler is insulating particles.

4. The perovskite tandem solar cell according to claim 3, wherein, The insulating particles have a particle size of d1, and the transparent conductive oxide nanoparticles have a particle size of d2, and 0 ≤ |d1-d2| < 200.

5. The perovskite tandem solar cell according to claim 4, wherein, The ratio of d1 / d2 is 1:1 to 1:

20.

6. The perovskite tandem solar cell according to claim 4 or 5, wherein, d1 ranges from 1 nm to 150 nm.

7. The perovskite tandem solar cell according to claim 6, wherein, d1 ranges from 2nm to 40nm.

8. The perovskite tandem solar cell according to any one of claims 4 to 7, wherein, d2 ranges from 1 nm to 200 nm.

9. The perovskite tandem solar cell according to claim 8, wherein, d2 is 5nm to 50nm.

10. The perovskite tandem solar cell according to any one of claims 3 to 9, wherein, The mass ratio of the transparent conductive oxide nanoparticles to the insulating particles in the composite layer is 1 to 5:

1.

11. The perovskite tandem solar cell according to any one of claims 3 to 10, wherein, The insulating particles include one or more of the following: alumina particles, silicon oxide particles, zirconium oxide particles, yttrium oxide particles, polyvinyl chloride particles, polyethylene particles, polytetrafluoroethylene particles, chloroprene rubber particles, polyvinyl alcohol acetal particles, polyimide particles, polyamide-imide particles, polymaleimide particles, or polydiphenyl ether particles.

12. The perovskite tandem solar cell according to claim 1 or 2, wherein, The insulating filler is a non-particulate insulating material continuously filling the gap, and the non-particulate insulating material includes an organic polymer film.

13. The perovskite tandem solar cell according to claim 12, wherein, The non-particulate insulating material includes one or more of polystyrene and polyethylene oxide.

14. The perovskite tandem solar cell according to claim 12, wherein, The mass ratio of the transparent conductive oxide nanoparticles to the non-particulate insulating material in the composite layer is 3 to 10:

1.

15. The perovskite tandem solar cell according to any one of claims 1 to 14, wherein, The thickness of the composite layer is 3nm to 200nm.

16. The perovskite tandem solar cell according to any one of claims 1 to 15, wherein, The transparent conductive oxide nanoparticles include one or more of the following: indium tin oxide particles, fluorine-doped tin oxide particles, aluminum-doped zinc oxide particles, boron-doped zinc oxide particles, indium zinc oxide particles, antimony tin oxide particles, gallium indium zinc oxide particles, or lanthanide metal-doped indium oxide particles, gallium zinc oxide particles, and indium tungsten oxide particles.

17. The perovskite tandem solar cell according to any one of claims 1 to 16, wherein, The first sub-cell includes a first electrode, a first hole transport layer, a first perovskite layer and a first electron transport layer stacked sequentially, wherein the first electron transport layer is disposed on the surface of the composite layer facing away from the second sub-cell; The second sub-cell includes a second electrode, a second electron transport layer, and a second perovskite layer stacked sequentially, with the second perovskite layer disposed on the surface of the composite layer facing away from the first electron transport layer.

18. The perovskite tandem solar cell according to claim 17, wherein, The second sub-cell also includes a second hole transport layer, which is disposed between the composite layer and the second perovskite layer.

19. A method for fabricating a perovskite tandem solar cell, comprising the following steps: The first sub-cell was fabricated on the substrate; A composite layer is fabricated on the first sub-cell, the composite layer comprising transparent conductive oxide nanoparticles and an insulating filler; along the spreading direction of the composite layer, at least a portion of the transparent conductive oxide nanoparticles have gaps between adjacent transparent conductive oxide nanoparticles; the insulating filler fills the gaps. and A second sub-cell is prepared on the surface of the composite layer opposite to the first sub-cell.

20. The method for preparing a perovskite tandem solar cell according to claim 19, wherein, The insulating filler is insulating particles. The composite layer is prepared on the first sub-cell by the following steps: A slurry containing the transparent conductive oxide nanoparticles and insulating particles is coated onto the first sub-cell to form a slurry layer; and The slurry layer is then dried and cured.

21. The method for preparing a perovskite tandem solar cell according to claim 19, wherein, The insulating filler is insulating particles. The composite layer is prepared on the first sub-cell by the following steps: A slurry containing the transparent conductive oxide nanoparticles is coated onto the first sub-cell, and after drying and curing, a coating is formed. A slurry containing the insulating particles is applied to the coating, and the slurry containing the insulating particles penetrates into the coating; and The slurry containing the insulating particles is then dried and cured.

22. The method for preparing a perovskite tandem solar cell according to claim 19, wherein, The insulating filler is a non-particulate insulating material continuously filling the gaps, and the non-particulate insulating material includes an organic polymer film; the composite layer is prepared on the first sub-cell by the following steps: An insulating filler is dissolved in a solvent and mixed with transparent conductive oxide nanoparticles to form a slurry. This slurry is then coated onto the first sub-cell to form a slurry layer. The slurry layer is dried to form the composite layer.

23. A photovoltaic module comprising a perovskite tandem solar cell according to any one of claims 1 to 18, or a perovskite tandem solar cell prepared by the method comprising any one of claims 19 to 22.

24. A photovoltaic system comprising the photovoltaic module of claim 23.

25. An electrical device comprising the photovoltaic system of claim 24.

26. A power generation device comprising the photovoltaic system of claim 24.

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