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

Abstract

The present application relates to a perovskite tandem solar cell and a preparation method therefor, a photovoltaic module, a system, and an electric device. The perovskite tandem solar cell comprises a first subcell, a composite layer, a contact improvement layer and a second subcell that are stacked in sequence, wherein the second subcell comprises a second perovskite layer and a second hole transport layer that are stacked, the second hole transport layer being disposed between the second perovskite layer and the composite layer; the material of the composite layer comprises transparent conductive oxide nanoparticles; and the contact improvement layer is disposed on the surface of the composite layer facing the second hole transport layer and comprises a material capable of passivating the second hole transport layer. The perovskite tandem solar cell in the present application has relatively high open-circuit voltage and optical-electrical conversion efficiency.

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Chinese Patent Application No. 202410841584.9, filed on June 26, 2024, entitled “Perovskite tandem solar cell, preparation method thereof, photovoltaic module, system and electric 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 thereof, a photovoltaic module, a system and an electric 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 function of the composite layer is to extract the carriers of the two sub-cells and then to recombine them. Currently, the composite layer material of perovskite tandem solar cells usually uses transparent conductive oxide (TCO). Compared with the continuous thin film of transparent conductive oxide formed by physical vapor deposition (PVD) and other methods, the composite layer formed by TCO nanoparticles can reduce the lateral conductivity of the composite layer and has good light transmittance, which has greater advantages in these aspects. However, the tandem solar cell with TCO nanoparticle composite layer also has the problem of low open circuit voltage, which further affects the photoelectric conversion efficiency of the tandem solar cell.

[0006] Therefore, how to improve the open circuit voltage of perovskite tandem solar cells using TCO nanoparticles as the composite layer material and improve its conversion efficiency has become one of the important research directions 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 conversion efficiency, and accordingly to provide a preparation method thereof, a photovoltaic module, a system and an electric device.

[0008] To achieve the above object, the first aspect of the present application provides a perovskite tandem solar cell, comprising:

[0009] a first sub-cell, a composite layer, a contact improvement layer and a second sub-cell arranged in sequence;

[0010] The second sub-cell comprises a second perovskite layer and a second hole transport layer arranged in sequence, and the second hole transport layer is arranged between the second perovskite layer and the composite layer.

[0011] The material of the composite layer comprises transparent conductive oxide nanoparticles, the contact improvement layer is arranged on the surface of the composite layer facing the second hole transport layer, and the contact improvement layer comprises a material capable of passivating the second hole transport layer.

[0012] The perovskite tandem solar cell described above comprises a contact improvement layer arranged on the surface of the composite layer facing the second hole transport layer, and the contact improvement layer comprises a material capable of passivating the second hole transport layer in the second sub-cell. The material has good contact with the hole transport layer material and can form good contact with the second hole transport layer. Therefore, by arranging the above-mentioned contact improvement layer between the composite layer and the second hole transport layer, the contact performance between the composite layer and the second hole transport layer can be improved, and the open circuit voltage and conversion efficiency of the tandem solar cell using the transparent conductive oxide nanoparticle composite layer can be improved.

[0013] In any embodiment, the material of the contact improvement layer comprises one or more of aluminum oxide, silicon oxide and nickel oxide. The above-mentioned oxide material can effectively improve the contact between the composite layer and the hole transport layer, thereby improving the open circuit voltage and conversion efficiency of the tandem solar cell using the transparent conductive oxide nanoparticle composite layer.

[0014] In any embodiment, the contact improvement layer is formed on the surface of the composite layer by atomic layer deposition. In this way, the contact improvement layer prepared by atomic layer deposition can reduce the amount of positive charges on the surface of the transparent conductive oxide nanoparticles, reduce the repulsive force between the composite layer and the second hole transport layer, enable better contact between the composite layer and the second hole transport layer, further improve the contact performance between the composite layer and the second hole transport layer, and further improve the open circuit voltage and conversion efficiency of the perovskite tandem solar cell.

[0015] In any embodiment, the contact improvement layer is a discontinuous film. Arranging the contact improvement layer in a discontinuous structure is conducive to the passage of charge carriers from the discontinuous part of the contact improvement layer, fully utilizes the contribution of the hole transport layer to the open circuit voltage, and improves the open circuit voltage of the perovskite tandem solar cell.

[0016] In any of the embodiments, the material in the contact improvement layer is discontinuously distributed in dots on the surface of the composite layer.

[0017] In any of the embodiments, the transparent conductive oxide nanoparticles include one or more of fluorine-doped tin oxide nanoparticles, indium tin oxide nanoparticles, aluminum-doped zinc oxide nanoparticles, boron-doped zinc oxide nanoparticles, indium zinc oxide nanoparticles, antimony tin oxide nanoparticles, gallium indium zinc oxide nanoparticles, or lanthanide-doped indium oxide particles, gallium zinc oxide particles, indium tungsten oxide particles. In this way, not only can holes and electrons be well recombined in the composite layer, but the stacked solar cell can also have a higher light absorption rate; and using nanoparticles as the composite layer can reduce the lateral conductivity of the composite layer compared to a deposited dense transparent conductive oxide film.

[0018] In any of the embodiments, the composite layer is a transparent conductive oxide nanoparticle film formed by drying a transparent conductive oxide nanoparticle dispersion coating. In this way, the composite layer is composed of transparent conductive oxide nanoparticles, and there are certain gaps in the lateral direction of the transparent conductive oxide nanoparticles, which is conducive to reducing the lateral conductivity of the composite layer.

[0019] In any of the embodiments, the transparent conductive oxide nanoparticle dispersion includes transparent conductive oxide nanoparticles, a dispersant, and a solvent. In this way, the dispersant can prevent the transparent conductive oxide nanoparticles in the dispersion from settling or agglomerating. The transparent conductive oxide nanoparticles in the transparent conductive oxide nanoparticle film have a dispersant on their surface.

[0020] In any of the embodiments, the second sub-cell further includes a second electron transport layer and a second electrode; the second electron transport layer is arranged on the surface of the second perovskite layer away from the second hole transport layer; and the second electrode is arranged on the surface of the second electron transport layer away from the second perovskite layer.

[0021] In any of the embodiments, the first sub-cell includes a first electron transport layer, a first perovskite layer, a first hole transport layer, and a first electrode; the first electron transport layer, the first perovskite layer, the first hole transport layer, and the first electrode are sequentially stacked on the surface of the composite layer away from the second sub-cell; or the first hole transport layer, the first perovskite layer, the first electron transport layer, and the first electrode are sequentially stacked on the surface of the composite layer away from the second sub-cell. In this way, the perovskite stacked solar cell is a full perovskite stacked solar cell, and the sub-cell can be a formal structure perovskite cell or a reverse structure perovskite cell.

[0022] In any embodiment, the second perovskite layer is a narrow band gap perovskite layer, the first perovskite layer is a wide band gap perovskite layer, and the band gap of the second perovskite layer is less than the band gap of the first perovskite layer.

[0023] In any embodiment, the material of the first hole transport layer and the second hole transport layer each independently comprises one or more of 2,2',7,7'-tetrakis(N,N-p-methoxyphenylamine)-9,9'-spirobifluorene, methoxytriphenylamine-fluoromethylformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, poly 3-hexyl thiophene, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-aniline)carbazole-spirobifluorene, polythiophene, phosphonic monomer, carbazolyl monomer, sulfonic monomer, triphenylamine monomer, aromatic monomer, metal oxide, cuprous iodide, and cuprous thiocyanate; wherein the metal element in the metal oxide comprises one or more of Ni, Mo, and Cu.

[0024] A second aspect of the present application provides a preparation method of a perovskite tandem solar cell, comprising the following steps:

[0025] Preparation of a first sub-cell on a substrate;

[0026] Coating of a transparent conductive oxide nanoparticle dispersion on the first sub-cell, and forming a composite layer after annealing;

[0027] Preparation of a contact improvement layer on the composite layer;

[0028] Sequential preparation of a second hole transport layer and a second perovskite layer of a second sub-cell on the contact improvement layer;

[0029] The contact improvement layer comprises a material capable of passivating the second hole transport layer.

[0030] The preparation method of the perovskite tandem solar cell described above in the present application sets the contact improvement layer on the surface of the composite layer facing the second hole transport layer, and the material in the contact improvement layer is capable of passivating the second hole transport layer in the second sub-cell; the material has good contact with the hole transport layer material and can form good contact with the second hole transport layer, so that the prepared perovskite tandem solar cell has a higher open circuit voltage and conversion efficiency.

[0031] In any embodiment, the preparation of the contact improvement layer on the composite layer comprises the following steps:

[0032] forming an oxide non-continuous thin film on a surface of the composite layer away from the first sub-cell by an atomic layer deposition method; the atomic layer deposition is performed for 3-15 cycles.

[0033] The number of cycles of the atomic layer deposition is controlled to prepare the non-continuous contact improvement layer, so that the amount of positive charges on the surface of the transparent conductive oxide nanoparticles is reduced, the repulsive force between the composite layer and the second hole transport layer is reduced, the composite layer and the second hole transport layer can be in better contact, the contact performance between the composite layer and the second hole transport layer is further improved, and the open circuit voltage and the conversion efficiency of the perovskite tandem solar cell are further improved.

[0034] In any embodiment, the atomic layer deposition is performed for 5-8 cycles. In this way, while the composite layer and the second hole transport layer have good contact, the influence of the contact improvement layer on the conductivity of the composite layer is further reduced, thereby further improving the open circuit voltage and the conversion efficiency of the perovskite tandem solar cell.

[0035] In any embodiment, the oxide in the contact improvement layer is discontinuously distributed in the form of dots.

[0036] In any embodiment, the oxide in the contact improvement layer includes one or more of aluminum oxide, silicon oxide, and nickel oxide. The above-mentioned oxide material can effectively improve the contact between the composite layer and the hole transport layer, thereby improving the open circuit voltage and the conversion efficiency of the tandem solar cell using the transparent conductive oxide nanoparticle composite layer.

[0037] In any embodiment, the transparent conductive oxide nanoparticle dispersion liquid includes transparent conductive oxide nanoparticles, a dispersing agent, and a solvent.

[0038] A third aspect of the present application provides a photovoltaic module including 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 perovskite tandem solar cell of the second aspect of the present application.

[0039] A fourth aspect of the present application provides a photovoltaic system including the photovoltaic module of the third aspect of the present application.

[0040] A fifth aspect of the present application provides an electric device including the photovoltaic system of the fourth aspect of the present application.

[0041] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will be apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF DRAWINGS

[0042] For a better description and illustration of the embodiments or examples of the applications disclosed herein, reference can be made to one or more of the accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the presently described embodiments or examples, and the best mode presently contemplated of these applications. Moreover, in all the drawings, like reference numerals refer to like parts throughout the several views. In the drawings:

[0043] FIG. 1 is a schematic diagram of a structure of a perovskite tandem solar cell according to an embodiment of the present application.

[0044] Reference numerals: 10, perovskite tandem solar cell; 11, first sub-cell; 12, composite layer; 13, second sub-cell; 14, contact improvement layer; 111, first electron transport layer; 112, first perovskite layer; 113, first hole transport layer; 114, first electrode; 131, second perovskite layer; 132, second hole transport layer; 133, second electron transport layer; 134, second electrode. DETAILED DESCRIPTION

[0045] Hereinafter, some embodiments of a perovskite tandem solar cell, a method of manufacturing the same, a photovoltaic module, a system, and an electric device according to the present application will be explained in detail with appropriate reference to the accompanying drawings. However, there will be cases where unnecessary detailed explanation is omitted. For example, there will be cases where detailed explanation of matters known well, repeated explanation of substantially the same structure are omitted. This is to avoid the following explanation from becoming unnecessarily lengthy and to facilitate understanding by those skilled in the art. In addition, the drawings and the following explanation are provided so that those skilled in the art can fully understand the present application, and are not intended to limit the subject matter recited in the claims.

[0046] 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.

[0047] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0048] 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.

[0049] In this application, unless otherwise specified, 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.

[0050] 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.

[0051] As used herein, "combinations thereof", "any combination thereof", "any combination manner thereof" and the like include all suitable combination manners of any two or more of the listed items.

[0052] As used herein, "suitable", "suitable", "any suitable manner" and the like are subject to the implementation of the technical solutions of the present application.

[0053] As used herein, "preferably", "better", "better", "preferably" only describe the better effect of the implementation or embodiment, and it should be understood that it does not constitute a limitation on the protection scope of the present application. If there are multiple "preferably" in a technical solution, if there is no special description, and there is no contradictory relationship or mutual restriction, each "preferably" is independent.

[0054] In the present application, "further", "further", "particularly" and the like are used to describe the purpose, indicating the difference in content, but should not be understood as a limitation on the protection scope of the present application.

[0055] In the present application, the terms "first", "second", "third", "fourth" and the like in "first aspect", "second aspect", "third aspect", "fourth aspect" and the like are only for the purpose of description, and cannot be understood as indicating or implying relative importance or quantity, nor can it be understood as implying the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth" and the like only serve the purpose of non-exhaustive enumeration description, and it should be understood that they do not constitute a closed limitation on the quantity.

[0056] In the present application, the term "room temperature" generally refers to 4℃ to 35℃, which can refer to 20℃±5℃. In some embodiments of the present application, room temperature refers to 20℃ to 30℃.

[0057] In the present application, the units related to the data range, if only the right end point is followed by a unit, it means that the units of the left end point and the right end point are the same. For example, 3h-5h or 3h-5h means that the units of the left end point "3" and the right end point "5" are both h (hours).

[0058] The weight of the related components mentioned in the specification of the embodiments of the present application can not only refer to the content of each component, but also represent the proportional relationship between the weights of each component, therefore, as long as the content of the related components in the specification of the embodiments of the present application is enlarged or reduced in proportion, it is within the scope disclosed in the specification of the embodiments of the present application. Further, the weight described in the specification of the embodiments of the present application can be μg, mg, g, kg and other mass units commonly known in the chemical industry.

[0059] As used herein, unless otherwise indicated, "alkyl" refers to a saturated hydrocarbon radical of a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof, which loses one hydrogen atom to form a monovalent radical. The phrase comprising this term, for example, "C1-9alkyl" refers to an alkyl group comprising from 1 to 9 carbon atoms, which can be, independently of each other, C1alkyl, C2alkyl, C3alkyl, C4alkyl, C5alkyl, C6alkyl, C7alkyl, C8alkyl, or C9alkyl, on 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(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).

[0060] As used herein, unless otherwise indicated, "heteroalkyl" refers to a non-carbon atom substituted alkyl group, wherein the non-carbon atom can be a N atom, an O atom, an S atom, a P atom, etc. The following are illustrated with O, N, and S. For example, if a carbon atom in an alkyl group that is attached to an adjacent group is replaced with 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), respectively. If a carbon atom in an alkyl group that is not directly attached to an adjacent group is replaced with 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), respectively. If a terminal carbon atom of an alkyl group is replaced with 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 mercaptoalkyl group (e.g., -CH2CH2-SH). Phrases containing this term, such as "Ci-C9heteroalkyl" or "C1-C9heteroalkyl" mean, independently at each occurrence, a C1heteroalkyl, C2heteroalkyl, C3heteroalkyl, C4heteroalkyl, C5heteroalkyl, C6heteroalkyl, C7heteroalkyl, C8heteroalkyl, or C9heteroalkyl. 1-9 heteroalkyl" means a heteroalkyl group containing 1 to 9 carbon atoms, which can be, independently at each occurrence, a C1heteroalkyl, C2heteroalkyl, C3heteroalkyl, C4heteroalkyl, C5heteroalkyl, C6heteroalkyl, C7heteroalkyl, C8heteroalkyl, or C9heteroalkyl.

[0061] As used herein, unless otherwise indicated, "cycloalkyl" and "non-aromatic cyclic hydrocarbon" mean a non-aromatic hydrocarbon (saturated or unsaturated) containing ring carbon atoms, which has lost a hydrogen atom from a ring to form a monovalent linking site directly on the ring. Cycloalkyl groups derived from non-aromatic saturated hydrocarbons can be designated as saturated cycloalkyl groups, and cycloalkyl groups derived from non-aromatic unsaturated hydrocarbons can be designated as unsaturated cycloalkyl groups. Cycloalkyl groups can be monocyclic, or spirocyclic, or bridged cyclic. Phrases containing this term, such as "C3-C9cycloalkyl" or "C3-C9cycloalkyl" mean, independently at each occurrence, a C3cycloalkyl, C4cycloalkyl, C5cycloalkyl, C6cycloalkyl, C7cycloalkyl, C8cycloalkyl, or C9cycloalkyl. Suitable examples include, but are not limited to: cyclopropyl 3-9 cycloalkyl" means a cycloalkyl group containing 3 to 9 carbon atoms, which can be, independently at each occurrence, a C3cycloalkyl, C4cycloalkyl, C5cycloalkyl, C6cycloalkyl, C7cycloalkyl, C8cycloalkyl, or C9cycloalkyl. Suitable examples include, but are not limited to: cyclopropyl cyclobutyl cyclopentyl cyclohexyl and cycloheptyl. Additionally, "cycloalkyl" can contain one or more double bonds. Representative examples of cycloalkyl groups containing double bonds include cyclopentenyl groups (including, but not limited to ), cyclohexenyl groups (including, but not limited to ) and cyclopentadienyl (including but not limited to ) and cyclobutadienyl (including but not limited to ) and cyclobutadienyl (including but not limited to ).

[0062] As used herein, and unless otherwise indicated, "heterocycloalkyl" means a heterocycloalkyl group in which at least one carbon atom has been replaced with a non-carbon atom, which can be an N atom, an O atom, an S atom, etc., and which can be a saturated ring or a partially unsaturated ring. Phrases containing this term, such as "C4-C9heterocycloalkyl," mean a heterocycloalkyl group containing 4 to 9 carbon atoms, which can be, independently of each other occurrence, a C4heterocycloalkyl, a C5heterocycloalkyl, a C6heterocycloalkyl, a C7heterocycloalkyl, a C8heterocycloalkyl, or a C9heterocycloalkyl. Suitable examples include, but are not limited to, dihydropyridyl, tetrahydropyridyl (piperidyl), tetrahydrothiophenyl, sulfoxidized tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, dihydroindolyl.

[0063] As used herein, and unless otherwise indicated, "aryl" means an aromatic hydrocarbon group derived from an aromatic hydrocarbon compound by removal of a hydrogen atom from a ring atom of the aromatic hydrocarbon, i.e., forming a monovalent site of attachment directly to a ring, which can be a monocyclic aryl, or a fused ring aryl, or a polycyclic aryl, where at least one ring is an aromatic ring system. For example, "C6-C10aryl" means an aryl group containing 6 to 10 carbon atoms, which can be, independently of each other occurrence, a C6aryl, a C7aryl, a C8aryl, a C9aryl, or a C 10 aryl. Also for example, "C6-C10aryl" means an aryl group containing 6 to 10 carbon atoms, which can be, independently of each other occurrence, a C6aryl, a C7aryl, a C8aryl, a C9aryl, or a C 10 aryl. Also for example, "C6-C10aryl" means an aryl group containing 6 to 10 carbon atoms, which can be, independently of each other occurrence, a C6aryl, a C7aryl, a C8aryl, a C9aryl, or a C 20 aryl. Also for example, "C6-C10aryl" means an aryl group containing 6 to 10 carbon atoms, which can be, independently of each other occurrence, a C6aryl, a C7aryl, a C8aryl, a C9aryl, or a C 10 aryl (e.g., naphthyl), a C 12 aryl (e.g., acenaphthyl, biphenyl), a C 13 aryl (e.g., fluorenyl), a C 14 aryl (e.g., anthryl, phenanthryl), a C 18 aryl (e.g., triphenylenyl), or a C 20 aryl (e.g., perylenyl). Suitable examples of aromatic hydrocarbon compounds include, but are not limited to, benzene, benzocyclobutene, biphenyl, indene, naphthalene, acenaphthene, fluorene, anthracene, phenanthrene, triphenylene, perylene, and derivatives thereof.

[0064] In the present text, "heteroaryl" is a heterocyclic group having 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, and the non-carbon atom can be, but is not limited to, an N atom, an O atom, an S atom, etc. For example, "C1-C 10 heteroaryl" means a heteroaryl group containing 1 to 10 carbon atoms, and each occurrence thereof can independently of one another be a C1 heteroaryl group (e.g., tetrazolyl), a C2 heteroaryl group (e.g., triazolyl, oxadiazolyl, etc.), a C3 heteroaryl group (e.g., imidazolyl), a C4 heteroaryl group (e.g., furanyl), a C5 heteroaryl group (e.g., pyridyl), a C6 heteroaryl group, a C7 heteroaryl group (e.g., benzimidazolyl), a C8 heteroaryl group (e.g., indolyl), a C9 heteroaryl group (e.g., quinolinyl), or a C 10 heteroaryl group (e.g., pyrrolo dipyridyl). Further, for example, "C3-C 20 heteroaryl" means a heteroaryl group containing 3 to 20 carbon atoms, and each occurrence thereof can independently of one another be, but is not limited to, a C2 heteroaryl group, a C3 heteroaryl group, a C4 heteroaryl group, a C5 heteroaryl group, a C6 heteroaryl group, a C8 heteroaryl group, a C9 heteroaryl group, a C 10 heteroaryl group, a C 12 heteroaryl group, a C 13 heteroaryl group, a C 14 heteroaryl group, a C 18 heteroaryl group, or a C 20 heteroaryl group. Suitable examples include, but are not limited to, heteroaryl groups derived from the following heteroaromatic rings (number of carbon atoms 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), tetrazole (C1), indole (C8), carbazole (C 12 ), pyrroloimidazole (C5), pyrrolopyrrole (C6), thienopyrrole (C6), thienothiophene (C6), furanopyrrole (C6), furanofuran (C6), thienofuran (C6), thienopyridine (C7), furanopyridine (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), naphthoquinoline (C8, such as ortho-naphthoquinoline), quinoxaline (C8), phenanthridine (C 13 ), berberine (C 11 ), quinazoline (C8), and quinoxaline (C8).

[0065] As used herein, unless otherwise indicated, "alkylene" refers to a hydrocarbon group derived by the removal of two hydrogen atoms from an alkane (or by the removal of one hydrogen atom from an alkyl group) having two monovalent radical centers, which can be a saturated branched alkyl group or a saturated straight chain alkyl group. For example, "C1-C9 alkylene" refers to an alkylene group containing from 1 to 9 carbon atoms in the alkyl portion, which can be independently at each occurrence 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-).

[0066] As used herein, unless otherwise indicated, "halogen" or "halo" refers to F, Cl, Br, or I.

[0067] As used herein, unless otherwise indicated, "amino" can be a primary amino group (-NH2), a secondary amino group (>NH), a tertiary amino group (>N-), or a quaternary amino group (>N + <).

[0068] As used herein, unless otherwise indicated, hydroxyl is -OH, carboxyl is -COOH, cyano is -CN, hydrazine is -NHNH2, sulfinic acid is -S(=O)OH, phosphinic acid is (*-)2P(=O)OH, sulfonic acid is -S(=O)2OH, phosphoric acid is (*-)P(=O)(OH)2, boronic acid is (*-)B(OH)2. In the phosphinic acid, the * indicates attachment to a carbon atom or H and at least one is to a carbon atom, in the phosphonic acid, the * indicates attachment to a carbon atom, and in the boronic acid, the * indicates attachment to a carbon atom.

[0069] At present, the composite layer material of the perovskite tandem solar cell usually adopts a transparent conductive oxide (TCO). Compared with a continuous thin film of the transparent conductive oxide deposited by a physical vapor deposition method or the like, the composite layer formed of TCO nanoparticles has greater advantages in reducing the horizontal conductivity of the composite layer and improving the light transmittance. However, the tandem solar cell with the TCO nanoparticle composite layer has a problem of a low open-circuit voltage, which affects the photoelectric conversion efficiency of the tandem solar cell. In view of this, the present application improves the structure and the preparation method of the perovskite tandem solar cell, thereby effectively improving the open-circuit voltage and the conversion efficiency of the tandem solar cell with the TCO nanoparticle composite layer.

[0070] Referring to FIG. 1, some embodiments of the present application provide a perovskite tandem solar cell 10, which includes a first sub-cell 11, a contact improvement layer 14, a composite layer 12 and a second sub-cell 13 arranged in sequence; wherein the second sub-cell 13 includes a second perovskite layer 131 and a second hole transport layer 132 arranged in sequence, and the second hole transport layer 132 is arranged between the second perovskite layer 131 and the composite layer 12; the material of the composite layer 12 includes transparent conductive oxide nanoparticles, and the contact improvement layer 14 is arranged on the surface of the composite layer 12 facing the second hole transport layer 132, and the contact improvement layer 14 includes a material capable of passivating the second hole transport layer 132 in the second sub-cell 13.

[0071] The reason why the open-circuit voltage of the tandem solar cell using the transparent conductive oxide nanoparticle composite layer 12 is low is mainly that the transparent conductive oxide nanoparticle composite layer 12 is usually prepared by a paste coating method. After the transparent conductive oxide nanoparticle dispersion liquid is formed into a coating layer, the composite layer 12 is obtained after drying (such as annealing treatment). A dispersant needs to be added in the transparent conductive oxide nanoparticle dispersion liquid to avoid the transparent conductive oxide nanoparticles in the dispersion liquid from settling or agglomerating. The dispersant is adsorbed on the surface of the transparent conductive oxide nanoparticles, so that the transparent conductive oxide nanoparticles in the composite layer 12 have a large number of positive charges on the surface. The transparent conductive oxide nanoparticles with positive charges repel the hole transport layer in the perovskite sub-cell which directly contacts the composite layer 12, resulting in poor contact between the composite layer 12 and the hole transport layer, and further resulting in low open-circuit voltage of the perovskite tandem solar cell 10, which affects the conversion efficiency of the tandem solar cell.

[0072] The perovskite tandem solar cell 10 described above in the present application has the contact improvement layer 14 arranged on the surface of the composite layer 12 facing the second hole transport layer 132, and the contact improvement layer 14 includes a material capable of passivating the second hole transport layer 132 in the second sub-cell 13; the material of the contact improvement layer 14 has good contact with the hole transport layer material and can form good contact with the second hole transport layer 132. Therefore, by arranging the above-mentioned contact improvement layer 14 between the composite layer 12 and the second hole transport layer 132, the contact performance between the composite layer 12 and the second hole transport layer 132 can be improved, and the open-circuit voltage and conversion efficiency of the tandem solar cell using the transparent conductive oxide nanoparticle composite layer 12 can be improved.

[0073] It should be noted that the material capable of passivating the second hole transport layer 132 refers to that when the material is arranged at a position on the surface of the hole transport layer, the recombination rate at the position can be reduced; specifically, when there is a certain negative charge on the interface between the material and the hole transport layer, the material can accelerate the extraction of holes and prevent electrons from approaching, and thus the material is capable of passivating the hole transport layer. Since the negative charge on the interface of the material can form an electric field on the interface to accelerate the passage of holes, the hole extraction performance is higher than that without the electric field, that is, the interface contact can be improved.

[0074] In some embodiments, the material of the contact improvement layer 14 includes one or more of aluminum oxide, silicon oxide, and nickel oxide. The above-mentioned materials can effectively passivate the second hole transport layer 132 and effectively improve the contact between the recombination layer 12 and the hole transport layer, thereby improving the open-circuit voltage and conversion efficiency of the perovskite tandem solar cell using the transparent conductive oxide nanoparticle recombination layer 12.

[0075] In some embodiments, the contact improvement layer 14 is a discontinuous film formed on the surface of the recombination layer 12 by atomic layer deposition (ALD).

[0076] Generally, the material of the contact improvement layer 14, such as aluminum oxide, silicon oxide, and nickel oxide, has poor conductivity and large resistance. If the contact improvement layer 14 is prepared as a continuous film, the resistance between the recombination layer and the hole transport layer will be significantly increased, resulting in a decrease in the open-circuit voltage of the perovskite tandem solar cell 10. By preparing the contact improvement layer 14 as a discontinuous film, carriers can pass through the discontinuous part of the contact improvement layer 14, which is more conducive to improving the open-circuit voltage of the perovskite tandem solar cell 10.

[0077] In addition, the above-mentioned discontinuous contact improvement layer 14 is prepared by atomic layer deposition. During the atomic layer deposition process, the source (such as an aluminum source, a silicon source, a nickel source, etc.) used will react with the dangling bonds on the surface of the transparent conductive oxide nanoparticles, thereby changing the charge of the dispersant on the surface of the transparent conductive oxide nanoparticles, reducing the amount of positive charge on the surface of the transparent conductive oxide nanoparticles, and reducing the repulsive force between the recombination layer 12 and the second hole transport layer 132. The recombination layer 12 and the second hole transport layer 132 can be in better contact, further improving the contact performance between the recombination layer 12 and the second hole transport layer 132, and further improving the open-circuit voltage and conversion efficiency of the perovskite tandem solar cell 10.

[0078] It can be understood that when the material of the contact improvement layer 14 is a material capable of passivating the second hole transport layer 132 and having good conductivity, the contact improvement layer 14 can also adopt a continuous film structure.

[0079] In some embodiments, the material of the contact improvement layer 14 is one or more of aluminum oxide, silicon oxide, and nickel oxide; the material in the contact improvement layer 14 is in a dot-like non-continuous distribution on the surface of the composite layer 12. In this way, when a material with poor electrical conductivity such as aluminum oxide, silicon oxide, and nickel oxide is used, the material in the contact improvement layer 14 is in a dot-like non-continuous distribution, which can not only improve the contact performance of the composite layer 12 and the second hole transport layer 132, but also minimize the impact of the material of the contact improvement layer 14 on the electrical conductivity of the composite layer 12.

[0080] In some embodiments, by controlling the number of cycles when the contact improvement layer 14 is prepared by atomic layer deposition, the material in the contact improvement layer 14 can be controlled to be in a dot-like non-continuous distribution on the surface of the composite layer 12.

[0081] In some embodiments, the transparent conductive oxide nanoparticles used in the composite layer 12 include one or more of fluorine-doped tin oxide (FTO) nanoparticles, indium tin oxide (ITO) nanoparticles, aluminum-doped zinc oxide (AZO) nanoparticles, boron-doped zinc oxide (BZO) nanoparticles, indium zinc oxide (IZO) nanoparticles, antimony tin oxide (ATO) nanoparticles, gallium indium zinc oxide (IGZO) nanoparticles, or lanthanide metal-doped indium oxide particles, gallium zinc oxide particles, indium tungsten oxide particles.

[0082] The transparent conductive oxide nanoparticles described above have good electrical conductivity and light transmittance. When used as the composite layer 12 of the perovskite stacked solar cell 10, not only can holes and electrons be well recombined in the composite layer 12, but also the stacked solar cell can have a high light absorption rate. Moreover, when the transparent conductive oxide nanoparticles are used as the composite layer 12, compared to a dense transparent conductive oxide film formed by physical vapor deposition or the like, the lateral conductivity of the composite layer 12 can be reduced. In some specific examples, the transparent conductive oxide nanoparticles are indium tin oxide (ITO) nanoparticles.

[0083] In some embodiments, the composite layer 12 is a transparent conductive oxide nanoparticle film formed after the transparent conductive oxide nanoparticle dispersion coating is dried. That is, the transparent conductive oxide nanoparticle dispersion is first coated on the sub-cell to form a coating, and then the coating is dried to obtain a transparent conductive oxide nanoparticle film as the composite layer 12. The transparent conductive oxide nanoparticle dispersion includes transparent conductive oxide nanoparticles, a dispersant, and a solvent. The main function of the dispersant is to prevent the transparent conductive oxide nanoparticles in the dispersion from settling or agglomerating.

[0084] Referring to FIG. 1, in some embodiments, the second sub-cell 13 further comprises a second electron transport layer 133 and a second electrode 134; the second electron transport layer 133 is arranged on the surface of the second perovskite layer 131 away from the second hole transport layer 132; and the second electrode 134 is arranged on the surface of the second electron transport layer 133 away from the second perovskite layer 131. That is, the second sub-cell 13 comprises the second electrode 134, the second electron transport layer 133, the second perovskite layer 131 and the second hole transport layer 132 arranged in sequence, and the second hole transport layer 132 is arranged on the surface of the composite layer 12 away from the second sub-cell 13.

[0085] Referring to FIG. 1, in some embodiments, the first sub-cell 11 comprises a first electron transport layer 111, a first perovskite layer 112, a first hole transport layer 113 and a first electrode 114; the first electron transport layer 111, the first perovskite layer 112, the first hole transport layer 113 and the first electrode 114 are arranged in sequence on the surface of the composite layer 12 away from the second sub-cell 13. In this way, both the first sub-cell 11 and the second sub-cell 13 are perovskite solar cells. That is, the perovskite tandem solar cell 10 is a full perovskite tandem solar cell. The overall structure of the full perovskite tandem solar cell is the second electrode 134, the second electron transport layer 133, the second perovskite layer 131, the second hole transport layer 132, the contact improvement layer 14, the composite layer 12, the first electron transport layer 111, the first perovskite layer 112, the first hole transport layer 113 and the first electrode 114 arranged in sequence.

[0086] In some embodiments, the second perovskite layer 131 in the second sub-cell 13 is a narrow-bandgap perovskite layer, the first perovskite layer 112 in the first sub-cell 11 is a wide-bandgap perovskite layer, and the bandgap of the second perovskite layer 131 is smaller than that of the first perovskite layer 112. In the narrow-bandgap perovskite layer, the bandgap of the perovskite material is 1.1 eV to 1.4 eV; and in the wide-bandgap perovskite layer, the bandgap of the perovskite material is 1.6 eV to 2.3 eV.

[0087] In some embodiments, the material of the first hole transport layer 113 and the second hole transport layer 132 each independently comprises one or more of 2,2',7,7'-tetra(N,N-p-methoxyphenylamine)-9,9'-spirobifluorene, methoxytriphenylamine-fluoromethylformamide, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, poly 3-hexyl thiophene, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-phenyl)carbazole-spirobifluorene, polythiophene, phosphonic monomer, carbazyl monomer, sulfonic monomer, triphenylamine monomer, aromatic monomer, metal oxide, cuprous iodide, and cuprous thiocyanate. Among them, the metal element in the metal oxide comprises one or more of Ni, Mo, and Cu.

[0088] In some embodiments, the first electrode 114 and the second electrode 134 each independently comprises one or more of an organic conductive material, an inorganic conductive material, and an organic-inorganic hybrid conductive material. Optionally, comprises one or more of a transparent conductive oxide, carbon, metal, and alloy thereof. More optionally, comprises one or more of indium tin oxide (ITO), lanthanide metal-doped indium oxide, fluorine-doped tin oxide (FTO), antimony-doped tin oxide, boron-doped zinc oxide (BZO), aluminum zinc oxide (AZO), indium zinc oxide (IZO), gallium zinc oxide (GZO), indium tungsten oxide (IWO), Au, Ag, Cu, Al, Ni, Cr, Bi, Pt, Mg, Mo, W, and alloys thereof, graphite, graphene, carbon nanotube. Optionally, comprises one or more of Ag, Cu, C, Au, Al, ITO, AZO, BZO, and IZO. Further optionally, comprises one or more of Cu, Ag, Au.

[0089] In some embodiments, the first electron transport layer 111 and the second electron transport layer 133 each independently comprises, but is not limited to, one or more of the following materials and derivatives thereof: imide compounds, quinone compounds, fullerenes and derivatives thereof, methoxytriphenylamine-fluoroformamidine (OMeTPA-FA), calcium titanate (CaTiO3), lithium fluoride (LiF), calcium fluoride (CaF2), poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS), poly 3-hexyl thiophene (P3HT), triptycene-core triphenylamine (H101), 3,4-ethylenedioxythiophene-methoxytriphenylamine (EDOT-OMeTPA), N-(4-aniline)carbazole-spirobifluorene (CzPAF-SBF), polythiophene, metal oxide, silicon oxide (SiO2), strontium titanate (SrTiO3), calcium titanate, lithium fluoride, calcium fluoride, cuprous thiocyanate (CuSCN), and the like; wherein the metal element in the second metal oxide comprises 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, and Cr.

[0090] In some embodiments, the first perovskite layer 112 and the second perovskite layer 131 are perovskite-type metal halides, the chemical formula of which comprises ABX3 or A2CDX6. A represents a monovalent inorganic cation, an organic cation, or an organic-inorganic hybrid cation, B represents a divalent inorganic cation, an organic cation, or an organic-inorganic hybrid cation, C represents a monovalent inorganic cation, an organic cation, or an organic-inorganic hybrid cation, D represents a trivalent inorganic cation, an organic cation, or an organic-inorganic hybrid cation, and X represents a monovalent inorganic anion, an organic anion, or an organic-inorganic hybrid anion. A represents a monovalent inorganic cation, which optionally comprises one or more of Li + , Na + , K + , Rb + , and Cs + ; A represents an organic cation, which optionally comprises at least one of methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, formamidine, and imidazole, and more optionally comprises one or more of organic amine ions and Cs + . B comprises a divalent cation, which optionally comprises a divalent cation 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, etc. C represents a monovalent inorganic cation, which optionally comprises Cs + , Ag + , K + , and Rb +one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. 3+ one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu. - one or more of In, Bi, Sb, and Cu. More optionally, D comprises one or more of In, Bi, Sb, and Cu.

[0091] Some embodiments of the present application provide a method for manufacturing the perovskite tandem solar cell 10 described above, which comprises the following steps S100 to S400:

[0092] Step S100: preparing the first sub-cell 11 on a substrate.

[0093] In some embodiments, the substrate can be a glass substrate.

[0094] In some embodiments, the first electrode 114 is prepared on the glass substrate first, and the glass substrate with the first electrode 114 is dried before use. Then, a solution containing the first hole transport layer material is spin-coated on the first electrode 114, transferred to a hot stage for annealing to form the first hole transport layer 113. The perovskite precursor solution is spin-coated on the first hole transport layer 113, transferred to a hot stage for annealing to form the first perovskite layer 112. A layer of electron transport layer material is deposited on the first perovskite layer 112 by atomic layer deposition to form the first electron transport layer 111, thereby completing the preparation of the first sub-cell 11.

[0095] Step S200: coating a transparent conductive oxide nanoparticle dispersion on the first electron transport layer 111 of the first sub-cell 11 to form the composite layer 12 after annealing.

[0096] In some embodiments, the transparent conductive oxide nanoparticle dispersion comprises transparent conductive oxide nanoparticles, a dispersant, and a solvent. The annealing temperature can be 100°C, and the annealing time can be 10 min.

[0097] Step S300: preparing the contact improvement layer 14 on the composite layer 12.

[0098] In some embodiments, the contact improvement layer 14 is prepared on the composite layer 12 by the following method:

[0099] forming an oxide discontinuous thin film on the surface of the composite layer 12 away from the first sub-cell 11 by an atomic layer deposition method; wherein the number of cycles of atomic layer deposition is 3-15 times. The oxide discontinuous thin film is prepared on the composite layer 12 as the contact improvement layer 14 by the atomic layer deposition method. During the atomic layer deposition process, the source used will react with the dangling bonds on the surface of the transparent conductive oxide nanoparticles, thereby changing the charge of the dispersant on the surface of the transparent conductive oxide nanoparticles, reducing the amount of positive charge on the surface of the transparent conductive oxide nanoparticles, and reducing the repulsive force between the composite layer 12 and the subsequently prepared second hole transport layer 132. This allows the composite layer 12 and the second hole transport layer 132 to be in better contact, improves the contact performance between the composite layer 12 and the second hole transport layer 132, and improves the open-circuit voltage and conversion efficiency of the perovskite stacked solar cell 10.

[0100] In addition, the oxide as the material of the contact improvement layer 14 generally has poor electrical conductivity. If it is prepared as a continuous thin film, it will significantly increase the resistance between the composite layer 12 and the hole transport layer. By controlling the number of cycles of atomic layer deposition to be 3-15 times, the prepared contact improvement layer 14 is a discontinuous thin film structure, and the carriers can pass through the discontinuous part of the contact improvement layer 14, which is more conducive to improving the open-circuit voltage of the perovskite stacked solar cell 10.

[0101] It can be understood that the number of cycles of atomic layer deposition can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15.

[0102] In some embodiments, the oxide in the contact improvement layer 14 includes one or more of aluminum oxide, silicon oxide, and nickel oxide. The above-mentioned oxide material itself can play a passivation role on the second hole transport layer 132, and itself has good contact performance with the material of the second hole transport layer 132. Using the above-mentioned oxide as the material of the contact improvement layer 14 can further improve the contact performance between the composite layer 12 and the second hole transport layer 132, and further improve the open-circuit voltage and conversion efficiency of the perovskite stacked solar cell 10.

[0103] In some embodiments, the number of cycles of atomic layer deposition is 5-8, and the oxide in the contact improvement layer 14 is in a point-like discontinuous distribution. Controlling the number of cycles of atomic layer deposition to 5-8 can make the oxide in the contact improvement layer 14 form a point-like discontinuous distribution, while having a good contact between the composite layer 12 and the second hole transport layer 132, further reducing the influence of the contact improvement layer 14 on the conductivity of the composite layer 12, thereby further improving the open-circuit voltage and conversion efficiency of the perovskite stacked solar cell 10.

[0104] Step S400: sequentially preparing a second hole transport layer 132, a second perovskite layer 131, a second electron transport layer 133 and a second electrode 134 on the composite layer 12 and the contact improvement layer 14 to form the second sub-cell 13.

[0105] In some embodiments, a solution containing the material of the second hole transport layer 132 is spin-coated on the composite layer 12 and the contact improvement layer 14, transferred to a hot table for annealing to form the second hole transport layer 132; a perovskite precursor solution is spin-coated on the above-mentioned second hole transport layer 132, transferred to a hot table for annealing to form the second perovskite layer 131; an electron transport layer material is evaporated on the above-mentioned second perovskite layer 131 to form the second electron transport layer 133; then an electrode is prepared on the above-mentioned second electron transport layer 133 to form the second electrode 134; thereby forming the second sub-cell 13.

[0106] Some embodiments of the present application provide a photovoltaic module comprising the perovskite stacked solar cell 10 described above. The photovoltaic module of the present application has a higher open-circuit voltage and conversion efficiency by using the perovskite stacked solar cell 10 described above.

[0107] In the above-mentioned photovoltaic module, one or more perovskite stacked solar cells 10 can be selected according to specific application scenarios; further, in the above-mentioned photovoltaic module, a plurality of perovskite stacked solar cells 10 are connected in series or parallel to form a cell piece.

[0108] In some embodiments, the above-mentioned photovoltaic module further comprises a photovoltaic glass layer, an adhesive layer and a back plate.

[0109] The two surfaces of the cell piece are respectively provided with an adhesive layer, and the surface away from the cell piece in one of the adhesive layers is provided with a back plate, and the surface away from the cell piece in the other adhesive layer is provided with a photovoltaic glass layer.

[0110] The photovoltaic glass layer and the back plate are used to protect the perovskite stacked solar cell 10, and have the functions of sealing, insulation and waterproofing; the adhesive layer plays a role in bonding the photovoltaic glass layer and the cell piece, and bonding the back plate and the cell piece.

[0111] Optionally, the material of the photovoltaic glass layer is tempered glass, the material of the back plate is TPT (polyvinyl fluoride) or TPE (thermoplastic elastomer), and the material of the bonding layer is EVA (polyethylene-polyvinyl acetate copolymer).

[0112] Further, the above-mentioned photovoltaic module further comprises a junction box and an outer frame.

[0113] The junction box is used to protect the power generation system of the entire photovoltaic module, and it is equivalent to a current transfer station. When a short circuit occurs in a battery piece, the junction box will automatically disconnect the short-circuited battery string.

[0114] The outer frame can support and protect the entire photovoltaic module, and the frame can be made of aluminum alloy, which has excellent strength and corrosion resistance.

[0115] Further, the connection between the frame and other parts of the photovoltaic module is bonded and sealed by silicone. The photovoltaic module can convert solar energy into electrical energy, which can be stored in a storage battery or used to drive a load.

[0116] In some embodiments, the above-mentioned photovoltaic module is a solar cell panel.

[0117] Some embodiments of the present application provide a photovoltaic system comprising the above-mentioned photovoltaic module.

[0118] The photovoltaic system uses the perovskite tandem solar cell 10 in the above-mentioned photovoltaic module to directly convert solar radiation energy into electrical energy, which has high efficiency and good stability. Further, the above-mentioned photovoltaic system is a photovoltaic power generation system.

[0119] The photovoltaic module is the core part of the photovoltaic power generation system. In the above-mentioned photovoltaic system, one or more photovoltaic modules are included, which can be selected according to the specific application scenario. Further, when multiple photovoltaic modules are included in the above-mentioned photovoltaic system, the multiple photovoltaic modules form a photovoltaic array.

[0120] The above-mentioned photovoltaic system can be an independent photovoltaic power generation system or a grid-connected photovoltaic power generation system.

[0121] The independent photovoltaic power generation system includes a photovoltaic array, a battery pack, a charge controller, a power electronic converter (inverter), a load, etc. Its working principle is that solar radiation energy is first converted into electrical energy by the photovoltaic array, and then the electrical energy is converted by the power electronic converter to supply power to the load. At the same time, the excess electrical energy is stored in the energy storage device in the form of chemical energy through the charge controller. In this way, when the sunlight is insufficient, the energy stored in the battery can be converted into AC 220V, 50Hz electrical energy through the power electronic inverter, filtering and power transformer to supply AC load.

[0122] The grid-connected photovoltaic power generation system includes a photovoltaic array, a high-frequency DC / DC boost circuit, a power electronic converter (inverter), and a system monitor. The working principle is that solar radiation energy is converted by the photovoltaic array, then converted into high-voltage direct current through the high-frequency DC / DC boost circuit, and then converted into sinusoidal alternating current with the same frequency and voltage as the grid voltage through the power electronic inverter, and then output to the grid.

[0123] The above two photovoltaic power generation systems have their own characteristics, and can be selected according to specific application scenarios.

[0124] Some embodiments of the present application provide a power utilization device including the photovoltaic system described above.

[0125] In some embodiments, the power utilization device is a common device including the perovskite tandem solar cell 10 of the present application, such as in the fields of communication, transportation, industry and agriculture, lighting, etc. The power utilization device may, for example, include a satellite, a communication device, a traffic signal light, a lighthouse, a wireless telephone booth, a monitoring device in the field of oil drilling, a power supply system, a camping lamp, an electric vehicle, an electronic device charger, a building curtain wall, etc.

[0126] Hereinafter, embodiments of the present application will be described. The embodiments described below are exemplary and are intended to explain the present application only, and should not be understood as limiting the present application. In the embodiments, specific techniques or conditions not mentioned are performed according to the techniques or conditions described in the literature in the field or according to the product manual. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be obtained commercially.

[0127] Example 1:

[0128] The preparation steps of the perovskite tandem solar cell are as follows:

[0129] (1) First electrode preparation

[0130] A layer of indium tin oxide (ITO) thin film was deposited on a glass substrate as a first electrode by magnetron sputtering, and the glass substrate with the first electrode was sequentially cleaned with acetone-ethanol-deionized water, and then dried for use.

[0131] (2) First hole transport layer preparation

[0132] [4-(3,6-dimethoxy-9H-carbazol-9-yl)butyl]phosphonic acid (MeO-4PACz) was added to an ethanol solvent and stirred, and the MeO-4PACz ethanol solution was spin-coated onto the first electrode at a spin speed of 4000 rpm and a spin time of 30 s, then transferred to a hot stage and annealed at 100°C for 10 min to form a first hole transport layer.

[0133] (3) First perovskite layer preparation

[0134] A perovskite precursor solution was prepared by adding 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 into 1 mL of a mixed solvent of DMF and DMSO (volume ratio of DMF to DMSO was 3:1), stirring on a magnetic stirrer at a speed of 600 rpm for 8 h, and filtering. 100 μL of the perovskite precursor solution was spin-coated onto the first hole transport layer (spin-coated at a speed of 2000 rpm for 10 s and then at a speed of 4000 rpm for 25 s), and then 200 μL of chlorobenzene was added dropwise to the spin-coated perovskite precursor solution, followed by spin-coating of the perovskite precursor solution again (at a speed of 4000 rpm for 15 s), and then transferred to a hot plate to be annealed at 100°C for 15 min, thereby forming a first perovskite layer.

[0135] (4) First electron transport layer preparation

[0136] A 20-nm-thick SnO2 layer was prepared on the first perovskite layer using an atomic layer deposition (ALD) apparatus, thereby forming a first electron transport layer.

[0137] (5) Composite layer preparation

[0138] An ITO nanoparticle dispersion liquid was spin-coated at a speed of 4000 rpm for 30 s, and then annealed at 100°C for 10 min, thereby forming a composite layer. The ITO nanoparticle dispersion liquid was composed of ITO nanoparticles, a dispersant, and a solvent, isopropanol.

[0139] (6) Contact improvement layer preparation

[0140] A point-like aluminum oxide layer was prepared on the composite layer using an atomic layer deposition (ALD) apparatus, thereby forming a contact improvement layer. The process flow of the atomic layer deposition was as follows: passing an aluminum source (trimethylaluminum) for 1 s, purging for 10 s, passing a water source for 1 s, purging for 10 s, which was one cycle; and repeating the above cycle for 8 times.

[0141] (7) Second hole transport layer preparation

[0142] A poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) layer was spin-coated on the composite layer and the contact improvement layer (at a speed of 4000 rpm for 30 s), and then transferred to a hot plate to be annealed at 150°C for 10 min, thereby forming a second hole transport layer.

[0143] (8) Second perovskite layer preparation

[0144] A perovskite precursor solution was prepared by adding 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 into 1 mL of a mixed solvent of DMF and DMSO (volume ratio of DMF to DMSO was 3:1), stirring at a speed of 600 rpm on a magnetic stirrer for 2 h, and filtering; 100 μL of the perovskite precursor solution was spin-coated onto the second hole transport layer (first spin-coated at a speed of 1000 rpm and an acceleration of 200 rpm / s for 10 s, and then spin-coated at a speed of 3000 rpm and an acceleration of 1000 rpm / s for 20 s), and then 350 μL of ethyl acetate was added dropwise to the spin-coated perovskite precursor solution, followed by spin-coating the perovskite precursor solution again (at a speed of 4000 rpm for 20 s), and then transferred to a hot stage for annealing at 100°C for 10 min, to form a second perovskite layer.

[0145] (9) Preparation of a second electron transport layer

[0146] A 10-nm-thick bathocuproin (BCP) layer was deposited on the second perovskite layer to form a second electron transport layer.

[0147] (10) Preparation of a second electrode

[0148] A 100-nm-thick copper (Cu) layer was deposited on the second electron transport layer to form a second electrode. Thus, a perovskite tandem solar cell was obtained.

[0149] Example 2

[0150] This example was basically the same as Example 1, except that in step (6), the number of cycles of atomic layer deposition was 3.

[0151] Example 3

[0152] This example was basically the same as Example 1, except that in step (6), the number of cycles of atomic layer deposition was 5.

[0153] Example 4

[0154] This example was basically the same as Example 1, except that in step (6), the number of cycles of atomic layer deposition was 15.

[0155] Example 5

[0156] This example was basically the same as Example 1, except that in step (6), a silicon source (silicon tetrachloride) was used instead of trimethylaluminum in the atomic layer deposition process; and the contact improvement layer prepared correspondingly was a dot-shaped silicon oxide.

[0157] Example 6:

[0158] This example is basically the same as Example 1, except that in step (6), a nickel source (nickel (II) 1-dimethylamino-2-methyl-2-butoxy) is used instead of trimethylaluminum in the atomic layer deposition process; and the corresponding prepared contact improvement layer is a dot-shaped nickel oxide.

[0159] Example 7:

[0160] This example is basically the same as Example 1, except that in step (5), a fluorine-doped tin oxide (FTO) nanoparticle dispersion liquid is used instead of an ITO nanoparticle dispersion liquid to spin-coat to prepare a composite layer, and the formed material is a fluorine-doped tin oxide nanoparticle composite layer.

[0161] Example 8:

[0162] This example is basically the same as Example 1, except that in step (5), an aluminum-doped zinc oxide (AZO) nanoparticle dispersion liquid is used instead of an ITO nanoparticle dispersion liquid to spin-coat to prepare a composite layer, and the formed material is an aluminum-doped zinc oxide nanoparticle composite layer.

[0163] Comparative Example 1:

[0164] This comparative example is basically the same as Example 1, except that no contact improvement layer is provided between the composite layer and the second hole transport layer; that is, step (6) is not performed between step (5) and step (7).

[0165] Test method:

[0166] (1) Contact improvement layer test

[0167] The presence of the contact improvement layer is determined by testing the interface contact resistance. Specifically, the hole-conducting contact resistance is tested, and if the conductivity of the holes in a specific direction increases, it can be determined that a contact improvement layer is present.

[0168] (2) Performance test of perovskite tandem solar cell

[0169] The photoelectric conversion efficiency of the perovskite tandem solar cell is tested under standard test conditions (total irradiance 100 mW / cm 2 , measured cell temperature 25°C, spectral distribution AM1.5G) using a solar simulator, and readings are recorded using a JISSO 2400 series digital multimeter. The photoelectric conversion efficiency of the perovskite tandem solar cell is calculated as follows: PCE = P OUT / P OPT = V OC × J SC × (V MPP × J MPP ) / (V OC × JSC ) / P OPT =V OC ×J SC ×FF / P OPT

[0170] wherein P OUT , P OPT , V MPP (V), J MPP (mA / cm 2 ), V OC (V), J SC (mA / cm 2 ) and FF are the perovskite tandem solar cell working output power, incident light power, cell maximum power point voltage, cell maximum power point current, open circuit voltage, short circuit current and fill factor, respectively. OUT , P OPT , V MPP (V), J MPP (mA / cm 2 ), V OC (V) and J SC (mA / cm 2 ) are obtained by a digital multimeter.

[0171] The materials, parameters and performance test results of the perovskite tandem solar cells of the above examples and comparative examples are shown in Table 1.

[0172] Table 1

[0173] From the above data, it can be seen that the perovskite tandem solar cells of the examples of the present application have high open circuit voltage and conversion efficiency.

[0174] The technical features of the above-described examples can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above examples are described, however, as long as the combinations of the technical features do not contradict each other, they should be considered within the scope of the present disclosure.

[0175] The above-described examples only express several embodiments of the present application, and the description is relatively specific and detailed, but it should not be understood as limiting the scope of the patent. It should be noted that for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present patent should be subject to the appended claims, and the description and drawings 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, a contact improvement layer and a second sub-cell which are sequentially stacked; the second sub-cell comprises a second perovskite layer and a second hole transport layer which are sequentially stacked, the second hole transport layer is arranged between the second perovskite layer and the composite layer; the material of the composite layer comprises transparent conductive oxide nanoparticles, the contact improvement layer is arranged on the surface of the composite layer facing the second hole transport layer, and the contact improvement layer comprises a material capable of passivating the second hole transport layer.

2. The perovskite tandem solar cell of claim 1, wherein The material of the contact improvement layer comprises one or more of aluminum oxide, silicon oxide and nickel oxide.

3. The perovskite tandem solar cell according to claim 1 or 2, wherein The contact improvement layer is a discontinuous structure.

4. The perovskite tandem solar cell according to any one of claims 1 to 3, wherein The material in the contact improvement layer is discontinuously distributed in a dot shape on the surface of the composite layer.

5. The perovskite tandem solar cell according to any one of claims 1 to 4, wherein The transparent conductive oxide nanoparticles comprise one or more of fluorine-doped tin oxide nanoparticles, indium tin oxide nanoparticles, aluminum-doped zinc oxide nanoparticles, boron-doped zinc oxide nanoparticles, indium zinc oxide nanoparticles, antimony tin oxide nanoparticles, gallium indium zinc oxide nanoparticles, or lanthanide-doped indium oxide particles, gallium zinc oxide particles, indium tungsten oxide particles.

6. The perovskite tandem solar cell according to any one of claims 1 to 5, wherein The composite layer is a transparent conductive oxide nanoparticle film.

7. The perovskite tandem solar cell of any one of claim 6, wherein, The transparent conductive oxide nanoparticles in the transparent conductive oxide nanoparticle film have a dispersant on the surface.

8. The perovskite tandem solar cell according to any one of claims 1 to 7, wherein The second sub-cell further comprises a second electron transport layer and a second electrode; the second electron transport layer is arranged on the surface of the second perovskite layer away from the second hole transport layer; the second electrode is arranged on the surface of the second electron transport layer away from the second perovskite layer.

9. The perovskite tandem solar cell of claim 8, wherein, The first sub-cell comprises a first electron transport layer, a first perovskite layer, a first hole transport layer and a first electrode; the first electron transport layer, the first perovskite layer, the first hole transport layer and the first electrode are sequentially stacked on the surface of the composite layer away from the second sub-cell; or the first hole transport layer, the first perovskite layer, the first electron transport layer and the first electrode are sequentially stacked on the surface of the composite layer away from the second sub-cell.

10. The perovskite tandem solar cell of claim 9, wherein, The second perovskite layer is a narrow-bandgap perovskite layer, the first perovskite layer is a wide-bandgap perovskite layer, and the bandgap of the second perovskite layer is smaller than that of the first perovskite layer.

11. The perovskite tandem solar cell of claim 9 or 10, wherein The material of the first hole transport layer and the second hole transport layer each independently comprises one or more of 2,2',7,7'-tetra(N,N-p-methoxyanilino)-9,9'-spirobifluorene, methoxytriphenylamine-fluoromethylformamidine, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, poly 3-hexyl thiophene, triptycene-core triphenylamine, 3,4-ethylenedioxythiophene-methoxytriphenylamine, N-(4-anilino)carbazole-spirobifluorene, polythiophene, phosphonic monomer, carbazolyl monomer, sulfonic monomer, triphenylamine monomer, aromatic monomer, metal oxide, cuprous iodide, and cuprous thiocyanate; wherein the metal element in the metal oxide comprises one or more of Ni, Mo, and Cu. 12.A method for preparing a perovskite tandem solar cell, comprising the following steps: preparing a first sub-cell on a substrate; coating a transparent conductive oxide nanoparticle dispersion on the first sub-cell to form a composite layer after annealing; preparing a contact improvement layer on the composite layer; and sequentially preparing a second hole transport layer and a second perovskite layer of a second sub-cell on the contact improvement layer; wherein the contact improvement layer comprises a material capable of passivating the second hole transport layer.

13. The method of producing a perovskite tandem solar cell according to claim 12, wherein The preparation of the contact improvement layer on the composite layer comprises the following steps: forming a discontinuous oxide film on the surface of the composite layer away from the first sub-cell by an atomic layer deposition method; the number of cycles of the atomic layer deposition is 3-15.

14. The method of producing a perovskite tandem solar cell according to claim 13, wherein The number of cycles of the atomic layer deposition is 5-8.

15. The method of producing a perovskite tandem solar cell according to claim 13 or 14, wherein The oxide in the contact improvement layer is discontinuously distributed in the form of dots.

16. The method of producing a perovskite tandem solar cell according to any one of claims 13 to 15, wherein The oxide in the contact improvement layer comprises one or more of aluminum oxide, silicon oxide, and nickel oxide.

17. The method of producing a perovskite tandem solar cell according to any one of claims 12 to 16, wherein The transparent conductive oxide nanoparticle dispersion comprises transparent conductive oxide nanoparticles, a dispersant, and a solvent. 18.A photovoltaic module comprising the perovskite tandem solar cell of any one of claims 1-11, or the perovskite tandem solar cell prepared by the method of any one of claims 12-17. 19.A photovoltaic system comprising the photovoltaic module of claim 18. 20.An electric device comprising the photovoltaic system of claim 19.

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