Perovskite solar cell, laminated solar cell, preparation method and photovoltaic module

Abstract

The invention provides a perovskite solar cell, a laminated solar cell, a preparation method and a photovoltaic module. The perovskite solar cell comprises a perovskite layer, a passivation layer and a diffusion inhibition layer, the passivation layer and the diffusion inhibition layer are sequentially stacked on the perovskite layer, the passivation layer is made of an organic ammonium salt containing amino cations, the diffusion inhibition layer is made of an organic molecular compound, and the diffusion inhibition layer is made of an organic polymer. The organic molecular compound has a functional group connected to the tail end of a carbon chain, the functional group is selected from at least one of carboxyl and amino, and the number of carbon atoms in the organic ammonium salt is smaller than that in the organic molecular compound. The service life can be prolonged while the problem of a perovskite layer interface is solved.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and in particular to a perovskite solar cell, a stacked solar cell, a preparation method and a photovoltaic module. Background Art

[0002] Perovskite solar cells usually include a perovskite material layer and a carrier transport layer. There is poor interface contact between the perovskite material layer and the carrier transport layer. Specifically, there are problems such as energy level mismatch and energy level pinning effect at the interface between the perovskite material layer and the carrier transport layer, resulting in a more serious non-radiative recombination problem at the interface. Moreover, in the actual preparation process, due to the film-forming characteristics of the perovskite material, there are many defects on the surface of the formed perovskite material layer, which further aggravates the problem of non-radiative recombination. This has become an important factor restricting the further improvement of device efficiency.

[0003] Some traditional technologies propose to use materials containing organic cations to passivate the surface of the perovskite material layer to improve the interface problem between the perovskite material layer and the carrier transport layer. Although this method can improve the conversion efficiency of perovskite solar cells to a certain extent, it will also significantly affect the service life of perovskite solar cells.

[0004] However, materials containing organic cations usually also contain halogen anions. The low migration activation energy and small ionic radius of halogen anions make it very easy for halogen anions to migrate and diffuse into the carrier transport layer, destroying the charge extraction and transport capabilities of the carrier transport layer. Summary of the invention

[0005] Based on this, it is necessary to provide a perovskite solar cell that improves the interface problem of the perovskite layer and prolongs its service life in order to address the problems in the above-mentioned background technology.

[0006] In a first aspect, according to some embodiments of the present disclosure, a perovskite solar cell is provided, comprising a perovskite layer, a passivation layer and a diffusion inhibition layer, wherein the passivation layer and the diffusion inhibition layer are sequentially stacked on the perovskite layer, the material of the passivation layer comprises an organic ammonium salt containing amino cations, the material of the diffusion inhibition layer comprises an organic molecular compound, the organic molecular compound has a functional group connected to the end of a carbon chain, the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

[0007] In some embodiments of the present disclosure, the organic ammonium salt is selected from diamino cationic organic ammonium salts, and the number of carbon atoms in the organic ammonium salt is 2 to 4; and / or,

[0008] The molecular size of the organic ammonium salt is 6Å~13Å.

[0009] In some embodiments of the present disclosure, the diamino cationic organic ammonium salt is selected from one or more of ethylenediamine hydrohalide salts, ethylenediamine hydrohalide salt derivatives, propylenediamine hydrohalide salts, propylenediamine hydrohalide salt derivatives, butylene diamine hydrohalide salts and butylene diamine hydrohalide salt derivatives.

[0010] In some embodiments of the present disclosure, the thickness of the passivation layer is 0.5 nm to 50 nm.

[0011] In some embodiments of the present disclosure, the number of carbon atoms in the organic molecule compound is greater than 5, and the molecular weight of the organic molecule compound is 100-3000.

[0012] In some embodiments of the present disclosure, the organic molecular compound is selected from one or more of oleic acid, oleylamine, 3-dimethylaminopropylamine, polymethyl methacrylate and polydimethylacrylamide.

[0013] In some embodiments of the present disclosure, the diffusion suppression layer has a thickness of 0.5 nm to 50 nm.

[0014] In some embodiments of the present disclosure, the perovskite solar cell further includes an electron transport layer and a hole transport layer, the electron transport layer is disposed on a side of the diffusion inhibition layer away from the perovskite layer, and the hole transport layer is disposed on a side of the perovskite layer away from the diffusion inhibition layer.

[0015] In some embodiments of the present disclosure, the material of the perovskite layer is selected from formamidine-based perovskite materials.

[0016] In some embodiments of the present disclosure, the thickness of the perovskite layer is 500nm~2000nm.

[0017] In a second aspect, the present disclosure further provides a method for preparing a perovskite solar cell as described in any of the above embodiments, comprising the following steps:

[0018] preparing a perovskite layer;

[0019] coating a passivating agent containing an organic ammonium salt on the perovskite layer to form a passivating layer; and,

[0020] A diffusion suppressor containing an organic molecular compound is coated on the perovskite layer to form a diffusion suppressor layer.

[0021] The organic ammonium salt contains an amino cation, the organic molecular compound has a functional group connected to the end of the carbon chain, the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

[0022] In some embodiments of the present disclosure, the concentration of the organic ammonium salt in the passivating agent is 0.03 mg / mL to 3 mg / mL; and / or,

[0023] The concentration of the organic molecule compound in the diffusion inhibitor is 0.03 mg / mL to 3 mg / mL.

[0024] In some embodiments of the present disclosure, after applying the passivating agent, a first annealing step is further included; and / or,

[0025] After coating the diffusion inhibitor, the method further includes performing a second annealing treatment.

[0026] In some embodiments of the present disclosure, during the first annealing process, the annealing temperature is controlled to be 20° C. to 150° C., and the annealing time is controlled to be ≤30 min;

[0027] During the second annealing treatment, the annealing temperature is controlled to be 20° C. to 150° C., and the annealing time is controlled to be ≤30 min.

[0028] In a third aspect, the present disclosure further provides a stacked solar cell, which includes a silicon base cell and a perovskite solar cell as described in any of the above embodiments, wherein the perovskite solar cell is stacked on the silicon base cell, and the passivation layer and the diffusion inhibition layer are stacked on a side of the perovskite layer away from the silicon base cell.

[0029] In a fourth aspect, the present disclosure further provides a method for preparing a tandem solar cell as described in any of the above embodiments, comprising the following steps:

[0030] Providing the silicon substrate cell;

[0031] The perovskite solar cell is formed on the silicon substrate cell by using the method for preparing the perovskite solar cell as described in any of the above embodiments.

[0032] Furthermore, the present disclosure also provides a photovoltaic module, which includes a plurality of solar cells, wherein the solar cells are the perovskite solar cells as described in any of the above embodiments, or the solar cells are prepared by the preparation method as described in any of the above embodiments, or the solar cells are the stacked solar cells as described in any of the above embodiments.

[0033] The present disclosure adopts an organic ammonium salt with a shorter carbon chain as the material of the passivation layer, wherein the amino cation can chemically passivate the perovskite layer, improve the defects on the surface of the perovskite layer, and reduce non-radiative recombination. Further, the diffusion inhibition layer provided on the passivation layer includes an organic molecular compound, which has a longer carbon chain and an amino or carboxyl group connected to the end of the carbon chain. Both the amino group and the carboxyl group can coordinate with the metal ions on the surface of the perovskite material so that the carbon chain can be stably attached to the surface of the perovskite layer, and the carboxyl group can also condense with the amino cation in the passivation layer so that the carbon chain can be stably attached to the surface of the passivation layer, and the longer carbon chain can effectively inhibit the diffusion of water oxygen and halogen anions. The diffusion inhibition layer including the organic molecular compound can not only block water vapor and oxygen from contacting the passivation layer and the perovskite layer to cause passivation failure, but also hinder the diffusion of halogen anions in the passivation layer toward the carrier transport layer. Therefore, the setting of the passivation layer and the diffusion inhibition layer can extend its service life while improving the interface problem of the perovskite layer.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of the structure of a perovskite solar cell;

[0037] Figure 2 A schematic diagram illustrating the functions of the perovskite layer, the passivation layer, and the diffusion inhibition layer;

[0038] Figure 3 A schematic diagram of the structure of a tandem solar cell.

[0039] The reference numerals and their meanings are as follows:

[0040] 100, perovskite solar cell; 110, perovskite layer; 121, passivation layer; 122, diffusion inhibition layer; 130, electron transport layer; 140, hole transport layer; 150, buffer layer; 160, first transparent conductive layer; 170, anti-reflection layer; 180, first electrode; 200, silicon substrate cell; 210, silicon wafer; 220, first intrinsic silicon layer; 230, first doped silicon layer; 240, second intrinsic silicon layer; 250, second doped silicon layer; 260, second transparent conductive layer; 270, second electrode; 300, composite layer. DETAILED DESCRIPTION

[0041] To facilitate understanding of the present invention, a more comprehensive description of the present invention is provided below. The preferred embodiments of the present invention are given herein. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the content of the present invention more thorough and comprehensive.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this document pertains. The terms used herein in the specification of this document are only for describing specific embodiments and are not intended to limit this document.

[0043] It should be understood that when an element or layer is referred to as being "on, "adjacent to, "connected to, or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, "directly adjacent to, "directly connected to, or "directly coupled to" another element or layer, there may be no intervening elements or layers. It should be understood that although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are merely used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion.

[0044] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," and the like may be used herein for ease of description to describe the relationship of one element or feature to other elements or features. It should be understood that the spatially relative terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "over" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be otherwise oriented (e.g., rotated 90 degrees or other orientations) and the spatial descriptors used may be interpreted accordingly.

[0045] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be a limitation of the present disclosure. When used herein, the singular forms "a", "an" and "the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0046] The present disclosure provides a perovskite solar cell, which includes a perovskite layer, a passivation layer and a diffusion inhibition layer, wherein the passivation layer and the diffusion inhibition layer are sequentially stacked on the perovskite layer, the material of the passivation layer includes an organic ammonium salt containing amino cations, the material of the diffusion inhibition layer includes an organic molecular compound, the organic molecular compound has a functional group connected to the end of a carbon chain, the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

[0047] It can be understood that organic ammonium salt refers to an organic ionic compound composed of anions and amino cations, and the amino cations are connected to carbon chains. Generally, the amino cations in organic ammonium salts can effectively passivate the defects on the surface of perovskite materials. However, the migration activation energy of halogen anions in organic ammonium salts is low and the ionic radius is small, which makes it very easy for halogen anions to migrate and diffuse into the carrier transport layer, destroying the charge extraction and transport capabilities of the carrier transport layer.

[0048] In the perovskite solar cell of the present disclosure, the number of carbon atoms in the organic ammonium salt is less than that in the organic molecular compound, and thus the carbon chain of the organic molecular compound is longer than that of the organic ammonium salt.

[0049] The present disclosure adopts an organic ammonium salt with a shorter carbon chain as the material of the passivation layer, wherein the amino cation can chemically passivate the perovskite layer, improve the defects on the surface of the perovskite layer, and reduce non-radiative recombination. Further, the diffusion inhibition layer provided on the passivation layer includes an organic molecular compound, which has a longer carbon chain and an amino or carboxyl group connected to the end of the carbon chain. Both the amino group and the carboxyl group can coordinate with the metal ions on the surface of the perovskite material so that the carbon chain can be stably attached to the surface of the perovskite layer, and the carboxyl group can also condense with the amino cation in the passivation layer so that the carbon chain can be stably attached to the surface of the passivation layer, and the longer carbon chain can effectively inhibit the diffusion of water oxygen and halogen anions. The diffusion inhibition layer including the organic molecular compound can not only block water vapor and oxygen from contacting the passivation layer and the perovskite layer to cause passivation failure, but also hinder the diffusion of halogen anions in the passivation layer toward the carrier transport layer. Therefore, the setting of the passivation layer and the diffusion inhibition layer can extend its service life while improving the interface problem of the perovskite layer.

[0050] Figure 1 Schematic diagram of the structure of a perovskite solar cell 100 in the present disclosure. Figure 1 As shown, the perovskite solar cell 100 includes a perovskite layer 110, a passivation layer 121 and a diffusion suppression layer 122, wherein the passivation layer 121 and the diffusion suppression layer 122 are sequentially stacked on the perovskite layer 110. The material of the passivation layer 121 includes an organic ammonium salt, and the material of the diffusion suppression layer 122 includes an organic molecular compound, wherein the organic molecular compound has a functional group connected to the end of a carbon chain, wherein the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

[0051] As some examples of this embodiment, the organic ammonium salt in the passivation layer 121 directly contacts the perovskite layer 110. This allows the amino cations in the organic ammonium salt to be anchored in the perovskite layer 110, which can not only further enhance the chemical passivation effect of the passivation layer 121, but also improve the structural stability of the passivation layer 121.

[0052] As some examples of this embodiment, the organic ammonium salt is selected from diamino cation organic ammonium salt, that is, two amino cations are simultaneously connected to the carbon chain of the organic ammonium salt. The two amino cations have a stronger dipole moment and form N-type doping, which can also play a role of field passivation while chemically passivating. Field passivation can improve the interface energy level matching between the perovskite layer 110 and the carrier transport layer and reduce non-radiative recombination.

[0053] As some examples of this embodiment, the number of carbon atoms in the organic ammonium salt is 2 to 4. The distance between adjacent transition metal sites (such as lead sites) in the perovskite layer 110 is about 6.3Å, and the length of the carbon chain formed by 2 to 4 carbon atoms is relatively matched with the above distance, which is conducive to achieving a more comprehensive passivation effect.

[0054] As some examples of this embodiment, the molecular size of the organic ammonium salt can be 6Å~13Å. For example, the molecular size of the organic ammonium salt can be 6Å, 6.3Å, 7Å, 8Å, 9Å, 10Å, 11Å, 12Å, 12.6Å, 13Å, or the molecular size of the organic ammonium salt can be between any two of the above sizes. More preferably, the molecular size of the organic ammonium salt can be around 6.3Å or around 12.6Å.

[0055] As some examples of this embodiment, the organic ammonium salt is a hydrohalide salt of a diamine compound. For example, the diamino cationic organic ammonium salt is selected from one or more of ethylenediamine hydrohalide salts, ethylenediamine hydrohalide salt derivatives, propylenediamine hydrohalide salts, propylenediamine hydrohalide salt derivatives, butylene diamine hydrohalide salts and butylene diamine hydrohalide salt derivatives. Among them, ethylenediamine hydrohalide salts, propylenediamine hydrohalide salts and butylene diamine hydrohalide salts have similar properties and sizes, and can achieve good chemical passivation and field passivation effects.

[0056] Further, in this example, ethylenediamine hydrohalide salts may include but are not limited to one or more of ethylenediamine hydroiodide (EDAI2), ethylenediamine hydrochloride (EDACl2) and ethylenediamine hydrobromide (EDABr2). Ethylenediamine hydrohalide salt derivatives may be products in which one or more hydrogen atoms in ethylenediamine hydrohalide salts are further replaced by functional groups, wherein the substituents may be selected from but are not limited to halogen atoms, "-S-", "-S=", "-S=O", "-N-", "-N=", "-P=" and "-P=O". For example, ethylenediamine hydrohalide salt derivatives may be fluoroethylenediamine hydroiodide (F-EDAI2). It is understood that propylenediamine hydrohalide salt derivatives and butanediamine hydrohalide salt derivatives may also be understood similarly.

[0057] Further, in this example, the propylenediamine hydrohalide salt may include but is not limited to one or more of propylenediamine hydroiodide (PDAI2), propylenediamine hydrochloride (PDACl2) and propylenediamine hydrobromide (PDABr2). The propylenediamine hydrohalide salt derivative may be fluoropropylenediamine hydroiodide (F-PDAI2).

[0058] Further, in this example, the dibutylene diamine hydrohalide salt may include but is not limited to one or more of dibutylene diamine hydroiodide (BDAI2), dibutylene diamine hydrochloride (BDACl2) and dibutylene diamine hydrobromide (BDABr2). The dibutylene diamine hydrohalide salt derivative may be fluorodibutylene diamine hydroiodide (F-BDAI2).

[0059] As some other examples of this embodiment, the organic ammonium salt can also be selected from monoamino cation organic ammonium salts, that is, only one amino cation is connected to the carbon chain of the organic ammonium salt, which can also play a role in chemical passivation.

[0060] In this example, the monoamino cationic organic ammonium salt may be selected from one or more of ethylamine hydrohalide salts, ethylamine hydrohalide salt derivatives, propylamine hydrohalide salts, propylamine hydrohalide salt derivatives, butylamine hydrohalide salts, and butylamine hydrohalide salt derivatives.

[0061] As some examples of this embodiment, the thickness of the passivation layer 121 may be 0.5 nm to 50 nm. For example, the thickness of the passivation layer 121 may be 0.5 nm, 1 nm, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm. Setting the thickness of the passivation layer 121 within the above thickness range helps to obtain a better passivation effect while taking into account the carrier transmission effect.

[0062] As some examples of this embodiment, the number of carbon atoms in the organic molecular compound is more than 5, and the molecular weight of the organic molecular compound is 100 to 3000. The use of organic molecular compounds containing more than 5 carbon atoms can form a denser organic material film, so that the diffusion barrier layer has a better barrier effect.

[0063] As some examples of this embodiment, the organic molecular compound is selected from one or more of oleic acid (OA), oleylamine (OLA), 3-dimethylaminopropylamine (DMAPA), polymethyl methacrylate (PMMA) and polydimethylacrylamide (PDMA).

[0064] As some examples of this embodiment, the thickness of the diffusion suppression layer 122 may be 0.5 nm to 50 nm. For example, the thickness of the diffusion suppression layer 122 may be 0.5 nm, 1 nm, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm. Setting the thickness of the passivation layer 121 within the above thickness range helps to obtain better barrier properties while taking into account the carrier transmission capability.

[0065] Reference Figure 1As shown in some examples of this embodiment, the material of the perovskite layer 110 is selected from a formamidite-based perovskite material. Further, the chemical formula of the formamidite-based perovskite material can be represented by ABX3, wherein A at least includes a formamidite cation (FA + ), A may also include cesium ions (Cs + ), methylamine cation (MA + ) and rubidium ions (Rb + ), B can be selected from lead ions (Pb 2+ ) and tin ions (Sn 2+ ), X can be selected from one or more of chloride ion, bromide ion and iodide ion. It is understood that the chemical formula of the formamidinium cation is CH(NH2)2 + , the chemical formula of methylamine cation is CH3NH3 + When X is selected from a plurality of halogen anions, the material of the perovskite layer 110 is a mixed halogen perovskite material.

[0066] In this example, the material of the perovskite layer 110 may be FAPbX3. The raw materials for its preparation may include lead halide (PbX2) and formamidine halide (FAX). The lead halide may be PbI2, and the formamidine halide may be one or more of FAI and FABr.

[0067] Reference Figure 1 As shown, as some examples of this embodiment, the thickness of the perovskite layer 110 is 500nm~2000nm.

[0068] As some examples of this embodiment, the thickness of the perovskite layer 110 may be 500 nm, 600 nm, 800 nm, 1000 nm, 1200 nm, 1500 nm, 1700 nm, or 2000 nm, or the thickness of the perovskite layer 110 may be between any two of the above thicknesses.

[0069] Reference Figure 1As shown, as some examples of this embodiment, the perovskite solar cell 100 further includes an electron transport layer 130 and a hole transport layer 140, wherein the electron transport layer 130 is disposed on the side of the diffusion suppression layer 122 away from the perovskite layer 110, and the hole transport layer 140 is disposed on the side of the perovskite layer 110 away from the passivation layer 121. Among them, the hole transport layer 140 is used to extract the holes generated in the perovskite layer 110 and transmit them to the external circuit, and the electron transport layer 130 is used to extract the electrons generated in the perovskite layer 110 and transmit them to the external circuit. In this embodiment, the diamino cationic organic ammonium salt in the passivation layer 121 has a stronger dipole moment and forms N-type doping, so the passivation layer 121 is more suitable for improving the interface energy level matching between the perovskite layer 110 and the electron transport layer 130, has a hole blocking effect and can further reduce non-radiative recombination.

[0070] In this example, the material of the electron transport layer 130 may be selected from C 60 , 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) and tin oxide (SnO x )

[0071] In this example, the thickness of the electron transport layer 130 may be 5 nm to 30 nm. For example, the thickness of the electron transport layer 130 may be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm, or the thickness of the electron transport layer 130 may be between any two of the above thicknesses.

[0072] In this example, the material of the hole transport layer 140 may be nickel oxide (NiO x ).

[0073] In this example, the thickness of the hole transport layer 140 may be 5 nm to 30 nm. For example, the thickness of the hole transport layer 140 may be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm, or the thickness of the hole transport layer 140 may be between any two of the above thicknesses.

[0074] Reference Figure 1 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include a first transparent conductive layer 160 and a first electrode 180. The first transparent conductive layer 160 is stacked on a side of the perovskite layer 110 away from the silicon substrate cell 200, and the first electrode 180 is electrically connected to the first transparent conductive layer 160.

[0075] In this example, the material of the first transparent conductive layer 160 may be selected from conductive metal oxides. For example, the material of the first transparent conductive layer 160 may be selected from one or more of indium tin oxide (ITO), indium zinc oxide (IZO), tungsten-doped indium oxide (IWO), aluminum-doped zinc oxide (AZO), and fluorine-doped tin oxide (FTO).

[0076] In this example, the thickness of the first transparent conductive layer 160 may be 30 nm to 150 nm. For example, the thickness of the first transparent conductive layer 160 may be 30 nm, 50 nm, 70 nm, 90 nm, 100 nm, 120 nm, or 150 nm, or the thickness of the first transparent conductive layer 160 may be between any two of the above thicknesses.

[0077] In this example, the material of the first electrode 180 may include a metal material, for example, the material of the first electrode 180 includes one or more of gold, silver, copper, and aluminum.

[0078] In this example, the thickness of the first electrode 180 may be 50 nm to 400 nm. For example, the thickness of the first electrode 180 may be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, or 400 nm, or the thickness of the first electrode 180 may be between any two of the above thicknesses.

[0079] Reference Figure 1 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include an anti-reflection layer 170 , and the anti-reflection layer 170 is stacked on a side of the first transparent conductive layer 160 away from the perovskite layer 110 .

[0080] In this example, the thickness of the anti-reflection layer 170 may be 80 nm to 150 nm. For example, the thickness of the anti-reflection layer 170 may be 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, or 150 nm, or the thickness of the anti-reflection layer 170 may be between any two of the above thicknesses.

[0081] Reference Figure 1 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include a buffer layer 150. The buffer layer 150 is stacked on the side of the electron transport layer 130 away from the perovskite layer 110, and the buffer layer 150 is disposed between the electron transport layer 130 and the first transparent conductive layer 160. The buffer layer 150 is used to buffer the interface difference between the electron transport layer 130 and the first transparent conductive layer 160, and improve the quality of the first transparent conductive layer 160.

[0082] In this example, the thickness of the buffer layer 150 may be 5 nm to 30 nm. For example, the thickness of the buffer layer 150 may be 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, or 30 nm, or the thickness of the buffer layer 150 may be between any two of the above thicknesses.

[0083] Reference Figure 1 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include a counter electrode, which is disposed on a side of the perovskite layer 110 away from the first electrode 180. The counter electrode is used to conduct carriers in the perovskite layer 110, and the polarity of the counter electrode is opposite to that of the first electrode 180.

[0084] Figure 2 Schematic diagram for explaining the functions of the perovskite layer 110, the passivation layer 121 and the diffusion suppression layer 122. Figure 2 As shown, the amino cations in the organic ammonium salt in the passivation layer 121 can passivate the dangling bonds, vacancy defects and surface defects on the surface of the perovskite layer 110, however, there are halogen anions with a small ion radius in the passivation layer 121 and on the surface of the perovskite layer 110. The organic molecular compound with a longer carbon chain in the diffusion suppression layer 122 can form a thin film and block the diffusion of halogen anions toward the electron transport layer 130.

[0085] Figure 1 The method of the perovskite solar cell 100 shown includes steps S1.1 to S1.3, which are specifically as follows.

[0086] Step S1.1, preparing a perovskite layer 110.

[0087] Combination Figure 1 From the content shown, it can be understood that before preparing the perovskite layer 110, a substrate containing a counter electrode and a hole transport layer 140 can be provided, and the perovskite layer 110 can be prepared on the hole transport layer 140 of the substrate.

[0088] As some examples of this embodiment, the step of preparing the perovskite layer 110 includes: preparing a first precursor material and a second precursor material in sequence, and annealing the first precursor material and the second precursor material to react to form the perovskite layer 110. It can be understood that the first precursor material and the second precursor material should be selected from two raw materials that can combine to affect the perovskite material.

[0089] In this example, the first precursor material may be selected from one or more of lead iodide (PbI2) and lead bromide (PbBr2).

[0090] In this example, the first precursor material may be prepared by physical vapor deposition, such as evaporation.

[0091] In this example, the second precursor material may be selected from one or more of formamidine iodide (FAI), cesium bromide (CsBr), cesium chloride (CsCl), formamidine bromide (FABr), and methylamine chloride (MACl).

[0092] In this example, the second precursor material may be prepared by a solution method, such as spray coating, spin coating, blade coating, etc.

[0093] Step S1.2: coating a passivating agent containing the organic ammonium salt on the perovskite layer 110 to form the passivation layer 121 .

[0094] As some examples of this embodiment, the method of coating the passivating agent may be selected from spin coating, scraper coating, spray coating or evaporation.

[0095] It can be understood that the passivating agent may include an organic ammonium salt and a first solvent, and the organic ammonium salt may be dispersed in the first solvent. The passivation layer 121 can be formed by removing the first solvent.

[0096] As some examples of this embodiment, the first solvent in the passivator may be an organic solvent, such as an alcohol organic solvent. In this example, the first solvent may be selected from one or more of ethanol or isopropanol.

[0097] As some examples of this embodiment, the concentration of the organic ammonium salt in the passivator is 0.03mg / mL~3mg / mL. For example, the concentration of the organic ammonium salt can be 0.03mg / mL, 0.05mg / mL, 0.1mg / mL, 0.2mg / mL, 0.5mg / mL, 0.8mg / mL, 1mg / mL, 1.5mg / mL, 2mg / mL, 2.5mg / mL, 3mg / mL, or the concentration of the organic ammonium salt can also be between any two of the above concentrations. The use of the organic ammonium salt of the above concentration is conducive to forming a passivation layer 121 with a more uniform thickness, thereby obtaining a better passivation effect.

[0098] As some examples of this embodiment, after applying the passivating agent, a first annealing step is further included. The first annealing step is used to evaporate the first solvent in the passivating agent and allow the organic ammonium salt to bond to the surface of the perovskite layer 110, thereby obtaining a better chemical passivation effect and field passivation effect.

[0099] In this example, during the first annealing treatment, the annealing temperature is controlled to be 20°C~150°C. For example, the annealing temperature can be controlled to be 20°C, 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, or 150°C, or the annealing temperature can be between any two of the above temperatures.

[0100] In this example, during the first annealing process, the annealing time is controlled to be ≤30 min. For example, the annealing time can be controlled to be 0.5 min, 1 min, 2 min, 4 min, 8 min, 10 min, 20 min, 30 min, or the annealing time can be controlled to be between any two of the above times.

[0101] Step S1.3: coating a diffusion inhibitor containing an organic molecular compound on the perovskite layer 110 to form the diffusion inhibition layer 122 .

[0102] It can be understood that the step of forming the diffusion suppression layer 122 is performed after the step of forming the passivation layer 121 , and the diffusion suppression layer 122 covers a surface of the passivation layer 121 away from the perovskite layer 110 .

[0103] As some examples of this embodiment, the method of coating the diffusion inhibitor may be selected from spin coating, blade coating, spray coating or evaporation.

[0104] It can be understood that the diffusion inhibitor may include an organic molecule compound and a second solvent, and the organic molecule compound may be dispersed in the second solvent. The diffusion inhibition layer 122 can be formed by removing the second solvent.

[0105] As some examples of this embodiment, the second solvent in the diffusion inhibitor may be an organic solvent, such as an alcohol organic solvent. In this example, the second solvent may be selected from one or more of ethanol or isopropanol.

[0106] As some examples of this embodiment, the concentration of the organic molecule compound in the diffusion inhibitor is 0.03 mg / mL to 3 mg / mL. For example, the concentration of the organic molecule compound can be 0.03 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.2 mg / mL, 0.5 mg / mL, 0.8 mg / mL, 1 mg / mL, 1.5 mg / mL, 2 mg / mL, 2.5 mg / mL, 3 mg / mL, or the concentration of the organic molecule compound can also be between any two of the above concentrations. The use of the above concentration of organic molecule compounds is conducive to making the formed diffusion inhibition layer 122 more dense and more uniform in thickness.

[0107] As some examples of this embodiment, after coating the diffusion inhibitor, a second annealing step is further included to evaporate the second solvent in the diffusion inhibitor and make the organic ammonium salt more densely bonded.

[0108] In this example, during the second annealing treatment, the annealing temperature is controlled to be 20°C~150°C. For example, the annealing temperature can be controlled to be 20°C, 40°C, 60°C, 80°C, 100°C, 120°C, 140°C, or 150°C, or the annealing temperature can be between any two of the above temperatures.

[0109] In this example, during the second annealing process, the annealing time is controlled to be ≤30 min. For example, the annealing time can be controlled to be 0.5 min, 1 min, 2 min, 4 min, 8 min, 10 min, 20 min, 30 min, or the annealing time can be controlled to be between any two of the above times.

[0110] Combination Figure 1 As shown, after forming the diffusion suppression layer 122 , the step of preparing the electron transport layer 130 , the first transparent conductive layer 160 and the first electrode 180 on the surface of the diffusion suppression layer 122 away from the perovskite layer 110 may also be included.

[0111] Furthermore, after preparing the electron transport layer 130 and before preparing the first transparent conductive layer 160 , a step of preparing the buffer layer 150 may be further included. After preparing the first transparent conductive layer 160 , a step of preparing the anti-reflection layer 170 may be further included.

[0112] It can be understood that after the above steps S1.1 to S1.3, the following Figure 1 The perovskite solar cell 100 is shown.

[0113] Furthermore, the present disclosure also provides a tandem solar cell. Figure 3 Schematic diagram of the structure of the tandem solar cell. Figure 3 As shown, the tandem solar cell includes a silicon substrate cell 200 and a perovskite solar cell 100 in the present disclosure. The perovskite solar cell 100 is stacked on the silicon substrate cell 200, and the passivation layer 121 and the diffusion suppression layer 122 are stacked and arranged on a side of the perovskite layer 110 away from the silicon substrate cell 200.

[0114] Among them, the perovskite solar cell 100 is arranged on the silicon substrate cell 200 to form a stacked solar cell, which can maintain the advantage of fully capturing sunlight, thereby generating a higher photocurrent.

[0115] Reference Figure 3As shown in some examples of this embodiment, the tandem solar cell further includes a composite layer 300. The composite layer 300 is disposed between the silicon substrate cell 200 and the perovskite solar cell 100, and is electrically connected to the silicon substrate cell 200 and the perovskite solar cell 100. The composite layer 300 is used to promote the transmission of carriers between the silicon substrate cell 200 and the perovskite solar cell 100.

[0116] In this example, the material of the composite layer 300 may be a transparent conductive material such as a conductive metal oxide, etc. For example, the material of the composite layer 300 may be selected from one or more of indium tin oxide, indium zinc oxide, tungsten-doped indium oxide, aluminum-doped zinc oxide, and fluorine-doped tin oxide.

[0117] In this example, the thickness of the composite layer 300 may be 2 nm to 30 nm. For example, the thickness of the composite layer 300 may be 2 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, or the thickness of the composite layer 300 may be between any two of the above thicknesses.

[0118] Reference Figure 3 As shown in some examples of this embodiment, the perovskite solar cell 100 includes a hole transport layer 140 and an electron transport layer 130. The arrangement of the hole transport layer 140 and the electron transport layer 130 can refer to Figure 1 The perovskite solar cell 100 is arranged in the manner shown.

[0119] In this example, the hole transport layer 140, the perovskite layer 110 and the electron transport layer 130 are sequentially disposed on a side of the composite layer 300 away from the silicon substrate cell 200. Further, the hole transport layer 140 may directly contact the composite layer 300.

[0120] Reference Figure 3 As shown in some examples of this embodiment, the perovskite solar cell 100 includes a first electrode 180 and a first transparent conductive layer 160. The arrangement of the first electrode 180 and the first transparent conductive layer 160 can refer to Figure 1 The perovskite solar cell 100 is arranged in the manner shown.

[0121] Reference Figure 3 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include a buffer layer 150. The buffer layer 150 is stacked and disposed on a side of the electron transport layer 130 away from the perovskite layer 110.

[0122] Reference Figure 3 As shown, as some examples of this embodiment, the perovskite solar cell 100 may further include an anti-reflection layer 170 , and the anti-reflection layer 170 is stacked on a side of the first transparent conductive layer 160 away from the perovskite layer 110 .

[0123] Further, refer to Figure 3 As shown in some examples of this embodiment, the silicon substrate cell 200 includes a silicon wafer 210, a second electrode 270, and a second transparent conductive layer 260. The second transparent conductive layer 260 is stacked and arranged on a side of the silicon wafer 210 away from the perovskite solar cell 100, and the second electrode 270 is electrically connected to the second transparent conductive layer 260. It can be understood that the first transparent conductive layer 160 and the second transparent conductive layer 260 are used to conduct electrons and holes to the first electrode 180 and the second electrode 270, respectively.

[0124] In this example, the material of the second transparent conductive layer 260 may be selected from conductive metal oxides. For example, the material of the second transparent conductive layer 260 may be selected from one or more of indium tin oxide, indium zinc oxide, tungsten-doped indium oxide, aluminum-doped zinc oxide, and fluorine-doped tin oxide.

[0125] In this example, the thickness of the second transparent conductive layer 260 may be 30 nm to 150 nm. For example, the thickness of the second transparent conductive layer 260 may be 30 nm, 50 nm, 70 nm, 90 nm, 100 nm, 120 nm, or 150 nm, or the thickness of the second transparent conductive layer 260 may be between any two of the above thicknesses.

[0126] In this example, the material of the second electrode 270 may include a metal material, for example, the material of the second electrode 270 includes one or more of gold, silver, copper, and aluminum.

[0127] In this example, the thickness of the second electrode 270 may be 50 nm to 400 nm. For example, the thickness of the second electrode 270 may be 50 nm, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, or 400 nm, or the thickness of the second electrode 270 may be between any two of the above thicknesses.

[0128] Reference Figure 3As shown, as some examples of this embodiment, in this tandem solar cell, the silicon base cell 200 may include a silicon wafer 210, a first intrinsic silicon layer 220, a second intrinsic silicon layer 240, a first doped silicon layer 230 and a second doped silicon layer 250. Among them, the doping type of the first doped silicon layer 230 is N-type, and the doping type of the second doped silicon layer 250 is P-type. The first intrinsic silicon layer 220 and the first doped silicon layer 230 are sequentially stacked and arranged on one side surface of the silicon wafer 210, and the second intrinsic silicon layer 240 and the second doped silicon layer 250 are sequentially stacked and arranged on the other side surface of the silicon wafer 210. In this embodiment, the first intrinsic silicon layer 220 and the first doped silicon layer 230 are arranged on the side surface of the silicon wafer 210 close to the perovskite solar cell 100. The second intrinsic silicon layer 240 and the second doped silicon layer 250 are arranged on the side surface of the silicon wafer 210 away from the perovskite solar cell 100.

[0129] The materials of the first intrinsic silicon layer 220 , the first doped silicon layer 230 , the second intrinsic silicon layer 240 , and the second doped silicon layer 250 may be independently selected from amorphous silicon or microcrystalline silicon.

[0130] Reference Figure 3 As shown, in this embodiment, the first intrinsic silicon layer 220 and the first doped silicon layer 230 may be stacked between the silicon wafer 210 and the composite layer 300 .

[0131] The present disclosure also provides a method for preparing Figure 3 The method for producing a stacked solar cell includes steps S2.1 to S2.2, which are specifically as follows.

[0132] Step S2.1, providing a silicon substrate cell 200.

[0133] In this embodiment, the structure of the silicon substrate battery 200 can refer to Figure 3 Specifically, the silicon substrate cell 200 includes a silicon wafer 210, a first intrinsic silicon layer 220, a second intrinsic silicon layer 240, a first doped silicon layer 230, and a second doped silicon layer 250. The first intrinsic silicon layer 220 and the first doped silicon layer 230 are sequentially stacked on one side of the silicon wafer 210, and the second intrinsic silicon layer 240 and the second doped silicon layer 250 are sequentially stacked on the other side of the silicon wafer 210.

[0134] As some examples of this embodiment, the first intrinsic silicon layer 220 and the first doped silicon layer 230 are sequentially stacked on the silicon wafer 210. The silicon substrate battery 200 further includes a second electrode 270 and a second transparent conductive layer 260. The second transparent conductive layer 260 is stacked on a surface of the second doped silicon layer 250 away from the silicon wafer 210, and the second electrode 270 is disposed on a side of the second transparent conductive layer 260 away from the silicon wafer 210.

[0135] As some examples of this embodiment, the doping type of the first doped silicon layer 230 is N-type, and the doping type of the second doped silicon layer 250 is P-type.

[0136] As some examples of this embodiment, the silicon substrate battery 200 can be provided by purchasing it from the market or by preparing it based on the silicon wafer 210. The specific preparation process can be designed accordingly according to the structure, and will not be described in detail here.

[0137] As some examples of this embodiment, the preparation method may further include a step of preparing a composite layer 300 on the silicon substrate cell 200 .

[0138] In this example, the composite layer 300 may be prepared by physical vapor deposition, such as sputtering.

[0139] Step S2.2, forming the perovskite solar cell 100 on the silicon substrate cell 200.

[0140] In this embodiment, the formation of the perovskite solar cell 100 may be performed by referring to the method for preparing the perovskite solar cell 100 shown in steps S1.1 to S1.3.

[0141] As some examples of this embodiment, forming a perovskite solar cell 100 includes the following steps: preparing a hole transport layer 140 on a silicon substrate cell 200, preparing a perovskite layer 110 on the hole transport layer 140, sequentially preparing a passivation layer 121 and a diffusion suppression layer 122 on the perovskite layer 110, preparing an electron transport layer 130 on the diffusion suppression layer 122, preparing a buffer layer 150 on the electron transport layer 130, preparing a first transparent conductive layer 160 on the buffer layer 150, preparing an anti-reflection layer on the first transparent conductive layer 160, and preparing a first electrode 180 on the anti-reflection layer.

[0142] In this example, the hole transport layer 140 may be prepared by physical vapor deposition, such as sputtering.

[0143] In this example, the method for preparing the perovskite layer 110 can refer to the content shown in step S1.1, the method for preparing the passivation layer 121 can refer to the content shown in step S1.2, and the method for preparing the diffusion inhibition layer 122 can refer to the content shown in step S1.3.

[0144] In this example, the electron transport layer 130 may be prepared by a solution method or a physical vapor deposition method, and the specific preparation method may be selected according to the material of the electron transport layer 130. The physical vapor deposition method may be an evaporation method.

[0145] In this example, the first transparent conductive layer 160 may be prepared by physical vapor deposition, such as sputtering.

[0146] In this example, the anti-reflection layer 170 may be prepared by chemical vapor deposition.

[0147] In this example, the first electrode 180 may be prepared by screen printing a conductive paste and then sintering it.

[0148] After steps S2.1 to S2.2, the following can be formed: Figure 3 The stacked solar cell shown.

[0149] The present disclosure also provides a photovoltaic module, which includes a plurality of solar cells, wherein the solar cells are the perovskite solar cells as described in any of the above embodiments, or the solar cells are prepared by the preparation method as described in any of the above embodiments, or the solar cells are the stacked solar cells as described in any of the above embodiments.

[0150] As an example of this embodiment, the photovoltaic assembly may further include a packaging structure, which may include a first packaging board and a second packaging board that are arranged opposite to each other, and the solar cell is arranged between the first packaging board and the second packaging board.

[0151] Furthermore, the present disclosure also provides the following more specific embodiments and comparative examples and corresponding performance results. The beneficial effects of the present disclosure will also be more easily understood through the following contents.

[0152] The silicon-based battery used in the following embodiments and comparative examples has the same structure. The silicon-based battery is based on an N-type silicon wafer, and both sides of the N-type silicon wafer are sequentially deposited with an intrinsic amorphous silicon layer and a doped amorphous silicon layer, the doped amorphous silicon layer above the N-type silicon wafer is an N-type doped amorphous silicon layer, and the doped amorphous silicon layer below the N-type silicon wafer is a P-type doped amorphous silicon layer. An ITO transparent conductive layer is stacked below the P-type doped amorphous silicon layer, and the bottom of the ITO transparent conductive layer is in contact with the silver electrode.

[0153] Example 1

[0154] A silicon-based battery is provided: an N-type single crystal silicon wafer with a thickness of 110 μm is used as a silicon substrate, a hydrogenated intrinsic amorphous silicon layer with a thickness of 5 nm and a phosphorus-doped amorphous silicon layer with a thickness of 15 nm are sequentially deposited on the front side of the silicon substrate, and a hydrogenated intrinsic amorphous silicon layer with a thickness of 7 nm, a boron-doped amorphous silicon layer with a thickness of 15 nm and a transparent conductive indium tin oxide layer with a thickness of 70 nm are sequentially deposited on the back side of the silicon substrate.

[0155] ITO was sputter-deposited as a composite layer on the silicon-based cell with a thickness of 10 nm.

[0156] Sputtering NiO on the composite layerx As the hole transport layer, the thickness of the hole transport layer was 15 nm.

[0157] PbI2 was evaporated on the hole transport layer, and then FAI was coated and annealed at 150°C for 15 min to form a perovskite layer with a thickness of 1000 nm.

[0158] A passivation agent was spin-coated on the perovskite layer, the solvent of the passivation agent was isopropanol, the solute was propylenediamine hydroiodide (PDAI2), and the concentration of PDAI2 was 0.5 mg / mL. After spin coating, the layer was annealed at 100° C. for 5 minutes to form a passivation layer.

[0159] A diffusion inhibitor was spin-coated on the perovskite layer, the solvent of the diffusion inhibitor was isopropanol, the solute was oleic acid (OA), and the concentration of OA was 0.5 mg / mL. After spin coating, the layer was annealed at 100° C. for 5 minutes to form a diffusion inhibition layer.

[0160] Sputtering C on the diffusion suppression layer 60 As the electron transport layer, the thickness of the electron transport layer was 15 nm.

[0161] Sputtering SnO on the electron transport layer x As a buffer layer, the buffer layer thickness is 15 nm.

[0162] ITO material is sputtered on the buffer layer as a transparent conductive layer, and MgF x As an anti-reflection layer. Conductive silver paste is screen-printed on the transparent conductive layer as an electrode.

[0163] Example 2

[0164] Example 2 is basically the same as Example 1, with the main difference being that Example 2 uses fluoroethylenediamine hydroiodide (F-EDAI2) as the solute of the passivating agent.

[0165] Example 3

[0166] Example 3 is basically the same as Example 1, with the main difference being that Example 3 uses propylenediamine hydroiodide as the solute of the passivating agent.

[0167] Example 4

[0168] Example 4 is basically the same as Example 1, with the main difference being that Example 4 uses pentamethylenediamine hydroiodide as the solute of the passivating agent.

[0169] Example 5

[0170] Example 5 is substantially the same as Example 1, with the main difference being that Example 5 uses oleylamine (OLA) as the solute of the diffusion inhibitor.

[0171] Example 6

[0172] Example 6 is substantially the same as Example 1, with the main difference being that Example 6 uses 3-dimethylaminopropylamine (DMAPA) as the solute of the diffusion inhibitor.

[0173] Example 7

[0174] Example 7 is substantially the same as Example 1, with the main difference being that Example 7 uses polydimethylacrylamide (PDMA) as the solute of the diffusion inhibitor.

[0175] Example 8

[0176] Example 8 is basically the same as Example 1, with the main differences being that the concentration of PDAI2 in the passivator of Example 8 is 0.05 mg / mL, and the concentration of OA in the diffusion inhibitor is 0.05 mg / mL.

[0177] Example 9

[0178] Example 9 is basically the same as Example 1, with the main differences being that the concentration of PDAI2 in the passivator of Example 9 is 0.01 mg / mL, and the concentration of OA in the diffusion inhibitor is 0.01 mg / mL.

[0179] Comparative Example 1

[0180] Comparative Example 1 is substantially the same as Example 1, with the main difference being that neither a passivation layer nor a diffusion suppression layer is formed in Comparative Example 1.

[0181] Comparative Example 2

[0182] Comparative Example 2 is substantially the same as Example 1, with the main difference being that in Comparative Example 2, only a passivation layer is formed, and no diffusion suppression layer is formed.

[0183] Comparative Example 3

[0184] Comparative Example 3 is substantially the same as Example 1, with the main difference being that in Comparative Example 3, only a diffusion suppression layer is formed, and no passivation layer is formed.

[0185] Comparative Example 4

[0186] Comparative Example 4 is substantially the same as Example 1, with the main difference being that in Comparative Example 4, the diffusion suppression layer is formed first, and then the passivation layer is formed.

[0187] Comparative Example 5

[0188] Comparative Example 5 is substantially the same as Example 1, with the main difference being that Comparative Example 5 uses propionic acid as the solute of the diffusion inhibitor.

[0189] Test 1: Testing the open circuit voltage V of the above embodiments and comparative examples OC , short circuit current JSC , fill factor FF and conversion efficiency PCE, the results can be seen in Table 1. Among them, the open circuit voltage comparison of the tandem solar cells of Example 1, Comparative Example 1 and Comparative Example 6 is shown in Figure 3 .

[0190] Test 2: The initial efficiency of the laminated solar cells of the above-mentioned embodiments and comparative examples was tested upon completion of preparation, and the efficiency of the unpackaged devices was tested after being placed in dry air (relative humidity of 5% to 10%) for 3 days, 5 days, 10 days, 20 days and 30 days, respectively. The relative efficiency of each embodiment and comparative example was calculated with each initial efficiency as 100%. The results are shown in Table 2.

[0191] Table 1

[0192]

[0193] As shown in Table 1, Example 1 uses PDAI2 to prepare the passivation layer and OA as the diffusion inhibition layer, and its filling factor reaches 81.71% and the conversion efficiency reaches 32.31%. Compared with Example 1, Comparative Example 1 does not prepare the passivation layer and the diffusion inhibition layer, and its conversion efficiency is only 28.31%, which is significantly lower than Example 1. Comparative Example 2 only prepares the passivation layer, and its conversion efficiency reaches 30.34%, but the efficiency of Comparative Example 2 decays significantly faster over time. Comparative Example 3 only prepares the diffusion inhibition layer, and its conversion efficiency reaches 29.27%. Combining Comparative Examples 1 to Comparative Examples 3, it can be found that preparing the passivation layer and the diffusion inhibition layer at the same time can increase the conversion efficiency by 4%, preparing the passivation layer alone can only increase the conversion efficiency by 2.03%, and preparing the diffusion inhibition layer alone can only increase the conversion efficiency by 0.96%. That is to say, the improvement brought by preparing the passivation layer and the diffusion suppression layer at the same time is greater than the sum of the improvements of the diffusion suppression layer alone and the passivation layer alone. This shows that there is a synergistic effect between the passivation layer and the diffusion suppression layer provided in the present disclosure, which can significantly improve the conversion efficiency of the perovskite solar cell.

[0194] Examples 2 to 4 respectively use other types of organic ammonium salts, and their conversion efficiencies are significantly better than those of Comparative Example 3 and are relatively close to those of Example 1, indicating that the use of other types of organic ammonium salts can also achieve similar passivation effects.

[0195] Examples 5 to 7 use other types of diffusion inhibitors, and their conversion efficiencies are better than those of Comparative Examples 2 and 4, indicating that the use of other types of diffusion inhibitors can also achieve similar diffusion inhibition effects. The conversion efficiency of Example 5 is relatively close to that of Example 1. The conversion efficiency of Example 6 is slightly lower than that of Example 1, which is mainly because the carbon chain length of the diffusion inhibitor used in Example 6 is relatively short, and the effect of blocking and inhibiting diffusion is relatively poor. The conversion efficiency of Example 7 is lower than that of Example 1. Referring to its open circuit voltage and short-circuit current, it can be seen that this is mainly because the molecular weight of the diffusion inhibitor used in Example 7 is relatively large, which causes a certain barrier to the transmission of carriers, resulting in a significantly low short-circuit current.

[0196] In Example 8 and Example 9, when preparing the passivation layer and the diffusion inhibition layer, the concentration of the passivation agent and the diffusion inhibitor used is relatively low, which makes it difficult for the prepared passivation layer and the diffusion inhibition layer to completely cover the perovskite layer, resulting in relatively poor passivation effect and diffusion inhibition effect. However, Example 8 and Example 9 are still better than Comparative Example 1, which also shows that the passivation layer and the diffusion inhibition layer can still significantly improve the performance of the perovskite solar cell.

[0197] In addition, Comparative Example 4 adjusts the stacking order of the diffusion suppression layer and the passivation layer, and its conversion efficiency is even lower than that of Comparative Example 2 in which the passivation layer is set alone. This is mainly because the passivation effect of the passivation layer is difficult to play, and the diffusion suppression layer is difficult to play a good passivation effect. Comparative Example 5 uses propionic acid with a shorter molecular chain to replace oleic acid with a longer molecular chain, and its conversion efficiency is similar to that of Comparative Example 2, which shows that propionic acid with a shorter molecular chain cannot play a role in blocking and inhibiting the diffusion of halogen anions.

[0198] Table 2

[0199]

[0200] As shown in Table 2, the solar cell of Comparative Example 1 was not prepared with a passivation layer or a diffusion inhibition layer, and its efficiency decay was very obvious after standing for 30 days. Compared with Comparative Example 1, Comparative Examples 2 and 3 prepared a passivation layer and a diffusion inhibition layer, respectively, which can improve the efficiency decay to a certain extent. Comparative Example 4 first formed a diffusion inhibition layer and then formed a passivation layer, and the efficiency decay was worse than that of Comparative Example 3. This shows that the order of setting the passivation layer and the diffusion inhibition layer has an impact on the efficiency decay, which may be because the later prepared passivation layer affects the diffusion inhibition effect of the previous diffusion inhibition layer.

[0201] In addition, compared with Comparative Example 2, Comparative Example 5 uses propionic acid with a shorter carbon chain as a diffusion inhibitor, and the improvement of efficiency decay by propionic acid is not obvious.

[0202] In Example 1, a passivation layer is first prepared, and then a diffusion suppression layer is prepared, which can further improve the efficiency attenuation on the basis of Comparative Examples 2 and 3. The specific material selection and concentration of Examples 2 to 9 are different from those of Example 1, but a passivation layer and a diffusion suppression layer are formed, and they are significantly better than the comparative examples, indicating that the combination of the passivation layer and the diffusion suppression layer can further improve the efficiency attenuation.

[0203] Please note that the above embodiments are for illustrative purposes only and are not meant to be limiting of this document.

[0204] It should be understood that, unless otherwise specified herein, there is no strict order restriction for the execution of the steps, and the steps may be executed in other orders. Moreover, at least a portion of the steps in the preparation process may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but may be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

[0205] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0206] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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.

Claims

1. A perovskite solar cell, characterized in that: The invention comprises a perovskite layer, a passivation layer and a diffusion inhibition layer, wherein the passivation layer and the diffusion inhibition layer are sequentially stacked on the perovskite layer, the material of the passivation layer comprises an organic ammonium salt containing amino cations, the material of the diffusion inhibition layer comprises an organic molecular compound, the organic molecular compound has a functional group connected to the end of a carbon chain, the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

2. The perovskite solar cell according to claim 1, characterized in that: The organic ammonium salt is selected from diamino cationic organic ammonium salts, and the number of carbon atoms in the organic ammonium salt is 2 to 4; and / or, The molecular size of the organic ammonium salt is 6Å~13Å.

3. The perovskite solar cell according to claim 2, characterized in that: The diamino cationic organic ammonium salt is selected from one or more of ethylenediamine hydrohalide salts, ethylenediamine hydrohalide salt derivatives, propylenediamine hydrohalide salts, propylenediamine hydrohalide salt derivatives, butylenediamine hydrohalide salts and butylenediamine hydrohalide salt derivatives.

4. The perovskite solar cell according to claim 1, characterized in that: The thickness of the passivation layer is 0.5nm~50nm.

5. The perovskite solar cell according to any one of claims 1 to 4, characterized in that: The number of carbon atoms in the organic molecule compound is greater than 5, and the molecular weight of the organic molecule compound is 100-3000.

6. The perovskite solar cell according to claim 5, characterized in that: The organic molecular compound is selected from one or more of oleic acid, oleylamine, 3-dimethylaminopropylamine, polymethyl methacrylate and polydimethylacrylamide.

7. The perovskite solar cell according to any one of claims 1 to 4 and 6, characterized in that: The thickness of the diffusion suppression layer is 0.5 nm to 50 nm.

8. The perovskite solar cell according to any one of claims 1 to 4 and 6, characterized in that: The perovskite solar cell further includes an electron transport layer and a hole transport layer. The electron transport layer is arranged on a side of the diffusion suppression layer away from the perovskite layer, and the hole transport layer is arranged on a side of the perovskite layer away from the diffusion suppression layer.

9. The perovskite solar cell according to any one of claims 1 to 4 and 6, characterized in that: The material of the perovskite layer is selected from formamidine-based perovskite materials.

10. The perovskite solar cell according to any one of claims 1 to 4 and 6, characterized in that: The thickness of the perovskite layer is 500nm~2000nm.

11. A method for preparing a perovskite solar cell, characterized in that: The steps include: preparing a perovskite layer; coating a passivating agent containing an organic ammonium salt on the perovskite layer to form a passivating layer; and, coating a diffusion inhibitor containing an organic molecular compound on the perovskite layer to form a diffusion inhibition layer; The organic ammonium salt contains an amino cation, the organic molecular compound has a functional group connected to the end of the carbon chain, the functional group is selected from at least one of a carboxyl group and an amino group, and the number of carbon atoms in the organic ammonium salt is less than the number of carbon atoms in the organic molecular compound.

12. The method for preparing a perovskite solar cell according to claim 11, characterized in that: The concentration of the organic ammonium salt in the passivating agent is 0.03 mg / mL to 3 mg / mL; and / or, The concentration of the organic molecule compound in the diffusion inhibitor is 0.03 mg / mL to 3 mg / mL.

13. The method for preparing a perovskite solar cell according to any one of claims 11 to 12, characterized in that: After applying the passivating agent, the method further comprises performing a first annealing step; and / or, After coating the diffusion inhibitor, the method further includes performing a second annealing treatment.

14. The method for preparing a perovskite solar cell according to claim 13, characterized in that: During the first annealing treatment, the annealing temperature is controlled to be 20°C to 150°C, and the annealing time is controlled to be ≤30min; During the second annealing treatment, the annealing temperature is controlled to be 20° C. to 150° C., and the annealing time is controlled to be ≤30 min.

15. A tandem solar cell, characterized in that: It comprises a silicon-based cell and a perovskite solar cell as claimed in any one of claims 1 to 10, wherein the perovskite solar cell is stacked on the silicon-based cell, and the passivation layer and the diffusion suppression layer are stacked on a side of the perovskite layer away from the silicon-based cell.

16. The method for preparing a tandem solar cell according to claim 15, characterized in that: The steps include: Providing the silicon substrate cell; The perovskite solar cell is formed on the silicon substrate cell by using the method for preparing the perovskite solar cell according to any one of claims 11 to 14.

17. A photovoltaic module, characterized in that: The invention comprises a plurality of solar cells, wherein the solar cells are the perovskite solar cells as described in any one of claims 1 to 10, or the solar cells are prepared by the preparation method as described in any one of claims 11 to 14, or the solar cells are the stacked solar cells as described in claim 15.

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