Passivation layer, inverted component, perovskite solar cell, preparation method and application

Abstract

The invention belongs to the photovoltaic field, and particularly relates to a passivation layer, an inverted assembly, a perovskite solar cell, a preparation method and application. The passivation layer according to the present invention comprises 5-bromo-2-(methylthio) pyrimidine-4, 6-diamine. The passivation layer provided by the invention can passivate surface defects of the perovskite light absorption layer and the electron transport layer, and inhibit interface recombination and defect recombination of the perovskite light absorption layer and the electron transport layer, thereby improving the photoelectric conversion efficiency of the perovskite solar cell.

Description

Technical Field

[0001] The present invention belongs to the field of photovoltaics, and in particular relates to a passivation layer, an inverted component, a perovskite solar cell, and a preparation method and use thereof. Background Art

[0002] In recent years, the device performance of inverted (pin) perovskite solar cells (PSCs) has been significantly improved due to the improvement of perovskite quality and interface properties. However, defects on the surface or in the bulk of halide perovskites can hinder charge transfer and / or transport, induce non-radiative recombination, and thus limit the open circuit voltage (Voc) and accelerate the degradation of perovskite solar cells. Specifically, interfacial recombination of minority carriers (holes in the perovskite layer) near the interface with majority carriers (electrons in the ETL) occurs directly, even at non-defect sites. Due to non-radiative recombination losses (especially at the perovskite / C60 interface), photovoltaic cells generally exhibit low power conversion efficiency (PCE).

[0003] Therefore, it is urgent to develop a passivation layer in perovskite solar cells that can passivate the surface defects of the perovskite light absorption layer and the electron transport layer and inhibit the interface recombination and defect recombination of the perovskite light absorption layer and the electron transport layer, so as to improve the photoelectric conversion efficiency of perovskite solar cells. Summary of the invention

[0004] In order to solve the problems existing in the prior art, the present invention introduces a passivation layer made of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine between the perovskite light absorption layer and the electron transport layer; wherein the diamine ligand molecules in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can repel minority carriers and reduce contact-induced interface recombination through field effect passivation; the sulfur-modified methylthio molecules in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can passivate surface defects and inhibit interface recombination through strong coordination and hydrogen bonding; the bromine in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can synergistically passivate the under-coordinated Pb 2+ In summary, the passivation layer introduced in the present invention can perform dual passivation on the perovskite light absorption layer and the electron transport layer, while inhibiting near-interface recombination and intrinsic defect recombination, thereby improving the photovoltaic performance of the perovskite solar cell.

[0005] Specifically, the present invention provides a passivation layer, which comprises 5-bromo-2-(methylthio)pyrimidine-4,6-diamine.

[0006] In one or more embodiments, the thickness of the passivation layer is 2-3 nm.

[0007] The invention provides a method for preparing a passivation layer of the invention, comprising: mixing 5-bromo-2-(methylthio)pyrimidine-4,6-diamine and a solvent to obtain a passivation layer precursor solution, and coating the passivation layer precursor solution to obtain a passivation layer.

[0008] In one or more embodiments, in the passivation layer precursor solution, the solvent is isopropyl alcohol and / or chlorobenzene.

[0009] In one or more embodiments, the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine in the passivation layer precursor solution is 5-10 mg / mL.

[0010] In one or more embodiments, the passivation layer precursor solution is coated by spin coating, blade coating or slit coating.

[0011] The present invention provides an inverted component, which comprises, in sequence from the thickness direction, a hole transport layer, a perovskite light absorption layer, a passivation layer of the present invention, and an electron transport layer.

[0012] In one or more embodiments, the perovskite light-absorbing layer includes a perovskite structure material, the chemical formula of the perovskite structure material is ABX3, the A-position cation is selected from one or more of formamidinium ions, cesium ions and methylamine ions, the B-position cation is a lead ion, and the X-position anion is a bromide ion and / or an iodide ion.

[0013] In one or more embodiments, the thickness of the perovskite light absorbing layer is 400-500 nm.

[0014] In one or more embodiments, the electron transport layer is C60 and / or a fullerene derivative.

[0015] In one or more embodiments, the electron transport layer has a thickness of 10-50 nm.

[0016] The present invention provides a method for preparing the inverted assembly of the present invention, the method comprising the following steps:

[0017] (1) depositing the perovskite light absorbing layer on the surface of the hole transport layer;

[0018] (2) depositing the passivation layer on the surface of the perovskite light absorbing layer;

[0019] (3) Depositing the electron transport layer on the surface of the passivation layer to obtain the inverted component.

[0020] In one or more embodiments, in step (1), the raw material of the perovskite structure material and the solvent are mixed to obtain a perovskite precursor solution, and then the perovskite precursor solution is coated on the surface of the hole transport layer, and then annealed to obtain the perovskite light absorbing layer.

[0021] The present invention provides a perovskite solar cell comprising the inverted assembly of the present invention.

[0022] The present invention provides use of a passivation layer in preparing a perovskite solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of perovskite solar cells prepared according to some embodiments of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0025] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0026] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0027] In this article, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0028] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0029] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0030] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0031] The present invention provides a passivation layer, which may contain 5-bromo-2-(methylthio)pyrimidine-4,6-diamine.

[0032] In the present invention, the thickness of the passivation layer can be 2-3 nm, such as 2.0 nm, 2.2 nm, 2.4 nm, 2.6 nm, 2.8 nm, 3.0 nm. In the present invention, controlling the thickness of the passivation layer within the above range is beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0033] The invention provides a method for preparing a passivation layer of the invention, comprising: mixing 5-bromo-2-(methylthio)pyrimidine-4,6-diamine and a solvent to obtain a passivation layer precursor solution, and coating the passivation layer precursor solution to obtain a passivation layer.

[0034] In the passivation layer precursor solution of the present invention, the solvent may be isopropyl alcohol (IPA) and / or chlorobenzene.

[0035] In the passivation layer precursor solution of the present invention, the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can be 5-10 mg / mL, for example 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL. In the present invention, the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine in the passivation layer precursor solution is controlled within the above range, which is beneficial to improving the photoelectric conversion efficiency of the perovskite solar cell.

[0036] In the passivation layer precursor solution of the present invention, the coating method of the passivation layer precursor solution can be spin coating, blade coating or slit coating.

[0037] The present invention provides an inverted component, which may include a hole transport layer, a perovskite light absorption layer, a passivation layer, and an electron transport layer in sequence in the thickness direction. The passivation layer in the inverted component of the present invention can passivate the surface defects of the perovskite light absorption layer and the electron transport layer, inhibit the interface recombination and defect recombination of the perovskite light absorption layer and the electron transport layer, and thus improve the photoelectric conversion efficiency of the perovskite solar cell.

[0038] In the present invention, the hole transport layer may be a metal oxide and / or a self-assembled monolayer molecule.

[0039] In the present invention, the metal oxide may be one or more selected from nickel oxide, aluminum oxide and tin oxide.

[0040] In the present invention, the self-assembled monolayer molecules can be one or more selected from (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid, (2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl)phosphonic acid and (2-(9H-carbazole-9-yl)ethyl)phosphonic acid.

[0041] In the present invention, the thickness of the metal oxide may be 10-100 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm.

[0042] In the present invention, the thickness of the self-assembled monolayer molecules can be 2-5 nm, for example, 2 nm, 3 nm, 4 nm, 5 nm.

[0043] In the present invention, the thickness of the hole transport layer can be 2-105 nm, for example, 2 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 105 nm.

[0044] In the present invention, the perovskite light absorbing layer may include a perovskite structure material, the chemical formula of the perovskite structure material may be ABX3, and the A-position cation may be selected from the group consisting of formamidinium ions (CH(NH2)2 + , FA), cesium ions and methylamine ions (CH3NH3 + , MA), the B-position cation may be a lead ion, and the X-position anion may be a bromide ion and / or an iodide ion.

[0045] In the present invention, in terms of molar percentage, the formamidinium ion may account for 75%-85% of the total molar amount of the cations at the A site, for example 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%.

[0046] In the present invention, the cesium ions may account for 10%-20% of the total molar amount of the A-site cations, for example 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, by mole percentage.

[0047] In the present invention, the methylamine ions may account for 0-10% of the total molar amount of the A-site cations, for example 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, by mole percentage.

[0048] In the present invention, the bromide ion can account for 10%-30% of the total molar amount of the anion at the X position, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, by mole percentage.

[0049] In the present invention, the iodide ions may account for 70%-90% of the total molar amount of the anions at position X, for example 70%, 72%, 74%, 76%, 78%, 80%, 82%, 84%, 86%, 88%, 90%, by mole percentage.

[0050] In the present invention, the thickness of the perovskite light absorbing layer may be 400-500 nm, for example, 400 nm, 410 nm, 420 nm, 430 nm, 440 nm, 450 nm, 460 nm, 470 nm, 480 nm, 490 nm, and 500 nm.

[0051] In the present invention, the electron transport layer may be C60 and / or a fullerene derivative (PCBM).

[0052] In the present invention, the thickness of the electron transport layer may be 10-50 nm, for example, 10 nm, 20 nm, 30 nm, 40 nm, or 50 nm.

[0053] The present invention provides a method for preparing an inverted assembly, the method comprising the following steps:

[0054] (1) depositing a perovskite light absorbing layer on the surface of the hole transport layer;

[0055] (2) depositing a passivation layer on the surface of the perovskite light absorbing layer;

[0056] (3) Depositing an electron transport layer on the surface of the passivation layer to obtain an inverted component.

[0057] In step (1), the raw material of the perovskite structure material and the solvent may be mixed to obtain a perovskite precursor solution, and then the perovskite precursor solution is coated on the surface of the hole transport layer, followed by annealing to obtain the perovskite light absorbing layer.

[0058] In step (1), in the perovskite precursor solution, the solvent may be one or more selected from dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP) and N,N-dimethylformamide (DMF). In some embodiments, the solvent is a mixture of dimethyl sulfoxide and N,N-dimethylformamide in a volume ratio of (0.1-5):10, for example; in some embodiments, the solvent is a mixture of dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylformamide in a volume ratio of 1:(0.1-1):(8-9).

[0059] In step (1), the concentration of the perovskite structure substance in the perovskite precursor solution may be 1-2 mol / L, for example, 1 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, or 2 mol / L.

[0060] In step (1), the coating method of the perovskite precursor solution can be spin coating, slit coating, doctor blade coating, spray coating, screen printing or inkjet printing.

[0061] In step (1), the annealing time can be 100-120°C, for example, 100°C, 105°C, 110°C, 115°C, 120°C.

[0062] In step (1), the annealing temperature can be 10 to 30 min, for example, 10 min, 15 min, 20 min, 25 min, 30 min.

[0063] In step (3), the electron transport layer can be deposited by spin coating or evaporation.

[0064] The present invention provides a perovskite solar cell comprising an inverted assembly of the present invention. The passivation layer in the perovskite solar cell of the present invention can passivate the surface defects of the perovskite light absorption layer and the electron transport layer, inhibit the interface recombination and defect recombination of the perovskite light absorption layer and the electron transport layer, and thus improve the photoelectric conversion efficiency of the perovskite solar cell.

[0065] In the present invention, the perovskite solar cell may include a single-junction perovskite solar cell and a tandem perovskite solar cell.

[0066] In the present invention, the single-junction perovskite solar cell may include a conductive substrate, an inverted assembly and a back electrode.

[0067] In the present invention, a barrier layer may be further included between the inverted component and the back electrode of the single-junction perovskite solar cell.

[0068] In the single-junction perovskite solar cell of the present invention, the conductive substrate may include a substrate and a transparent conductive oxide material; preferably, the transparent conductive oxide material may be one or more selected from indium tin oxide, fluorine-doped tin dioxide and aluminum-doped zinc oxide.

[0069] In the single-junction perovskite solar cell of the present invention, the back electrode may be Ag, Cu or Au.

[0070] In the single-junction perovskite solar cell of the present invention, the thickness of the back electrode may be 100-1000 nm.

[0071] In the present invention, the stacked perovskite solar cell may include a bottom electrode, a bottom cell, a tunneling layer, a top cell and a top electrode, wherein the top cell includes an inverted assembly.

[0072] In the present invention, a barrier layer may be further included between the inverted component and the top electrode of the tandem perovskite solar cell.

[0073] In the stacked perovskite solar cell of the present invention, the bottom electrode may include a first transparent electrode layer and a first metal grid line.

[0074] In the stacked perovskite solar cell of the present invention, the first transparent electrode layer can be one or more of indium tin oxide (ITO), fluorine-doped tin oxide (FTO) and vanadium-doped titanium dioxide (VTTO).

[0075] In the stacked perovskite solar cell of the present invention, the first metal grid line may be Ag, Cu or Au.

[0076] In the tandem perovskite solar cell of the present invention, the bottom cell may be a crystalline silicon bottom cell.

[0077] In the stacked perovskite solar cell of the present invention, the tunneling layer may be one or more of indium tin oxide (ITO), indium zinc oxide (IZO) and vanadium-doped titanium dioxide (VTTO).

[0078] In the stacked perovskite solar cell of the present invention, the top electrode may include a second transparent electrode layer and a second metal grid line.

[0079] In the stacked perovskite solar cell of the present invention, the second transparent electrode layer may be ITO and / or IZO.

[0080] In the laminated perovskite solar cell of the present invention, the second metal grid line may be Ag, Cu or Au.

[0081] The method for preparing a single-junction perovskite solar cell of the present invention may include the following steps:

[0082] (1') depositing a hole transport layer on the surface of a conductive substrate;

[0083] (1) depositing a perovskite light absorbing layer on the surface of the hole transport layer;

[0084] (2) depositing a passivation layer on the surface of the perovskite light absorbing layer;

[0085] (3) depositing an electron transport layer on the surface of the passivation layer;

[0086] (3') A back electrode is deposited on the surface of the electron transport layer to obtain a single-junction perovskite solar cell.

[0087] In step (1'), the hole transport layer can be deposited by sputtering, spin coating, slit coating or doctor blade coating.

[0088] In step (3'), the back electrode can be deposited by spin coating, evaporation, sputtering, doctor blade coating or screen printing.

[0089] The method for preparing a laminated perovskite solar cell of the present invention may include the following steps:

[0090] (1”) depositing a bottom electrode and a tunneling layer on two surfaces of the bottom battery respectively, and depositing a hole transport layer on the surface of the tunneling layer;

[0091] (1) depositing a perovskite light absorbing layer on the surface of the hole transport layer;

[0092] (2) depositing a passivation layer on the surface of the perovskite light absorbing layer;

[0093] (3) depositing an electron transport layer on the surface of the passivation layer;

[0094] (3”) A top electrode is deposited on the surface of the electron transport layer to obtain a stacked perovskite solar cell.

[0095] In step (1"), the bottom electrode can be deposited by sputtering, spin coating, evaporation or screen printing.

[0096] In step (1"), the tunneling layer may be deposited by sputtering, chemical vapor deposition or evaporation.

[0097] In step (1"), the hole transport layer can be deposited by sputtering, spin coating, slit coating or doctor blade coating.

[0098] In step (3"), the top electrode can be deposited by sputtering, spin coating, evaporation or screen printing.

[0099] In the present invention, the sputtering may be magnetron sputtering.

[0100] Compared with the prior art, the present invention has the following beneficial effects: the present invention introduces a passivation layer made of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine between the perovskite light absorption layer and the electron transport layer; the diamine ligand molecules in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can repel minority carriers and reduce contact-induced interface recombination through field effect passivation; the sulfur-modified methylthio molecules in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can passivate surface defects and inhibit recombination through strong coordination and hydrogen bonds; the bromine in 5-bromo-2-(methylthio)pyrimidine-4,6-diamine can synergistically passivate the under-coordinated Pb 2+ defects, while suppressing near-interface recombination and defect recombination; In summary, the passivation layer introduced in the present invention can double passivate the interface between the perovskite light absorbing layer and the electron transport layer, while suppressing near-interface recombination and intrinsic defect recombination, thereby improving the photovoltaic performance of perovskite solar cells.

[0101] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples can all be purchased through commercial routes.

[0102] Example 1

[0103] Preparation of this example Figure 1 The perovskite solar cell shown in the figure has the following specific steps:

[0104] (1) polishing an N-type silicon wafer to obtain an N-type silicon wafer with a thickness of 300 nm; using plasma enhanced chemical vapor deposition (PECVD) to sequentially deposit a front intrinsic amorphous silicon with a thickness of 10 nm and an n-type amorphous silicon with a thickness of 15 nm on one side of the N-type silicon wafer, and the total thickness of the front intrinsic amorphous silicon and the n-type amorphous silicon is 25 nm; using PECVD to sequentially deposit a back intrinsic amorphous silicon with a thickness of 10 nm and a p-type amorphous silicon with a thickness of 10 nm on the other side of the N-type silicon wafer, and the back intrinsic amorphous silicon and the p-type amorphous silicon are 25 nm thick. The total thickness of crystalline silicon is 20nm; ITO is deposited on the surface of p-type amorphous silicon by magnetron sputtering to obtain a first transparent electrode layer with a thickness of 110nm; silver is evaporated on the surface of ITO by evaporation to obtain a first metal grid line with a thickness of 200nm, and the first transparent electrode layer and the first metal grid line together constitute a bottom electrode; ITO is deposited on the surface of n-type amorphous silicon by magnetron sputtering to obtain a tunneling layer with a thickness of 50nm; NiOx is deposited on the surface of the tunneling layer by magnetron sputtering to obtain a hole transport layer with a thickness of 30nm;

[0105] (2) FAI powder, MAI powder, CsI powder, PbBr2 and PbI2 powder were mixed according to FA 0.8 Cs 0.2 Pb(Br 0.2 I 0.8 )3 The theoretical molar ratio of each element is mixed and dissolved in a mixed solvent of DMF / DMSO (the volume ratio of DMF and DMSO is 4:1), wherein the theoretically generated perovskite structure material is FA 0.8 Cs 0.2 Pb(Br 0.2 I 0.8 )3, the concentration of the theoretically generated perovskite structure material is 1.7 mol / L; spin coating is performed in a one-step method using anisole as an anti-solvent, and then annealing is performed at 100°C for 20 minutes to obtain a perovskite light-absorbing layer with a thickness of 450 nm;

[0106] (3) dissolving 5-bromo-2-(methylthio)pyrimidine-4,6-diamine in IPA to obtain a passivation layer precursor solution having a 5-bromo-2-(methylthio)pyrimidine-4,6-diamine concentration of 5 mg / mL, and dynamically spinning the passivation layer precursor solution on the surface of the perovskite light absorbing layer by spin coating to obtain a passivation layer with a thickness of 3 nm;

[0107] (4) depositing C60 on the surface of the passivation layer by evaporation to obtain an electron transport layer with a thickness of 10 nm, and depositing SnO2 on the surface of the electron transport layer by atomic layer deposition to obtain a barrier layer with a thickness of 20 nm;

[0108] (5) IZO is deposited on the surface of the barrier layer by magnetron sputtering to obtain a second transparent electrode layer with a thickness of 50 nm, and Ag is deposited on the surface of the transparent electrode layer by evaporation to obtain a second metal grid line with a thickness of 200 nm. The second transparent electrode layer and the second metal grid line together constitute a top electrode, and a perovskite solar cell is obtained at the same time.

[0109] Example 2

[0110] The other conditions of this embodiment are the same as those of embodiment 1, except that the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine in the passivation layer precursor solution in step (3) of this embodiment is 10 mg / mL.

[0111] Comparative Example 1

[0112] This comparative example prepares a perovskite solar cell, and the specific steps are as follows:

[0113] (1) polishing an N-type silicon wafer to obtain an N-type silicon wafer with a thickness of 300 nm; using plasma enhanced chemical vapor deposition (PECVD) to sequentially deposit a front intrinsic amorphous silicon with a thickness of 10 nm and an n-type amorphous silicon with a thickness of 15 nm on one side of the N-type silicon wafer, and the total thickness of the front intrinsic amorphous silicon and the n-type amorphous silicon is 25 nm; using PECVD to sequentially deposit a back intrinsic amorphous silicon with a thickness of 10 nm and a p-type amorphous silicon with a thickness of 10 nm on the other side of the N-type silicon wafer, and the back intrinsic amorphous silicon and the p-type amorphous silicon are 25 nm thick. The total thickness of crystalline silicon is 20nm; ITO is deposited on the surface of p-type amorphous silicon by magnetron sputtering to obtain a first transparent electrode layer with a thickness of 110nm; silver is evaporated on the surface of ITO by evaporation to obtain a first metal grid line with a thickness of 200nm, and the first transparent electrode layer and the first metal grid line together constitute a bottom electrode; ITO is deposited on the surface of n-type amorphous silicon by magnetron sputtering to obtain a tunneling layer with a thickness of 50nm; NiOx is deposited on the surface of the tunneling layer by magnetron sputtering to obtain a hole transport layer with a thickness of 30nm;

[0114] (2) FAI powder, MAI powder, CsI powder, PbBr2 and PbI2 powder were mixed according to FA0.8 Cs 0.2 Pb(Br 0.2 I 0.8 )3 The theoretical molar ratio of each element is mixed and dissolved in a mixed solvent of DMF / DMSO (the volume ratio of DMF and DMSO is 4:1), wherein the theoretically generated perovskite structure material is FA 0.8 Cs 0.2 Pb(Br 0.2 I 0.8 )3, the concentration of the theoretically generated perovskite structure material is 1.7 mol / L; spin coating is performed in a one-step method using anisole as an anti-solvent, and then annealing is performed at 100°C for 20 minutes to obtain a perovskite light-absorbing layer with a thickness of 450 nm;

[0115] (3) depositing C60 on the surface of the passivation layer by evaporation to obtain an electron transport layer with a thickness of 10 nm, and depositing SnO2 on the surface of the electron transport layer by atomic layer deposition to obtain a barrier layer with a thickness of 20 nm;

[0116] (4) IZO is deposited on the surface of the barrier layer by magnetron sputtering to obtain a second transparent electrode layer with a thickness of 50 nm, and Ag is deposited on the surface of the transparent electrode layer by evaporation to obtain a second metal grid line with a thickness of 200 nm. The second transparent electrode layer and the second metal grid line together constitute a top electrode, and a perovskite solar cell is obtained at the same time.

[0117] Comparative Example 2

[0118] The other conditions of this comparative example are the same as those of Example 1, except that the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine in the passivation layer precursor solution in step (3) of this comparative example is 15 mg / mL.

[0119] Test Case

[0120] Device performance test of perovskite solar cells: Under 25°C and AM 1.5G standard solar spectrum, a solar simulator was used to set the voltage range to 2V to -0.5V, and the current output of the perovskite solar cells prepared in Example 1-2 and Comparative Example 1-2 at different voltages was tested, and the corresponding current-voltage (IV) characteristic curves were plotted, where the cell surface area was 1.1664cm 2 , the incident light power (Pin) is 100mW / cm 2 The open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of the perovskite solar cells prepared in Example 1-2 and Comparative Example 1-2 were obtained according to the characteristic curves.

[0121] (1) Open circuit voltage (Voc): The voltage value corresponding to when the current is equal to zero.

[0122] (2) Short-circuit current density (Jsc): The current value when the voltage is zero is the short-circuit current (Isc), and the current per unit battery surface area is the short-circuit current density.

[0123] (3) Fill factor (FF): The ratio of the maximum output power (Pmax) of the battery to the product of the open circuit voltage and the short circuit current. The calculation formula is (Pmax / Voc*Isc), where the maximum power point is the point where the battery output power reaches its maximum value.

[0124] (4) Photoelectric conversion efficiency (PCE): Photoelectric conversion efficiency refers to the ratio of maximum output power to incident light power (Pin), and the calculation formula is (Pmax / Pin)*100%.

[0125] The test results of the open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of the perovskite solar cells prepared in Example 1-2 and Comparative Example 1-2 are shown in Table 1.

[0126] Table 1: Open circuit voltage, short circuit current density, fill factor and photoelectric conversion efficiency of perovskite solar cells prepared in Examples 1-2 and Comparative Examples 1-2

[0127] <![CDATA[Jsc(mA / cm 2 )]]> Voc(V) FF(%) PCE(%) Example 1 18.70 1.84 76.03 26.25 Example 2 18.62 1.88 77.09 27.17 Comparative Example 1 18.28 1.83 75.06 25.47 Comparative Example 2 18.41 1.85 74.21 25.36

Claims

1. A passivation layer, characterized in that: The passivation layer includes 5-bromo-2-(methylthio)pyrimidine-4,6-diamine.

2. The passivation layer according to claim 1, characterized in that The thickness of the passivation layer is 2-3 nm.

3. A method for preparing the passivation layer according to claim 1, characterized in that: The method comprises: mixing 5-bromo-2-(methylthio)pyrimidine-4,6-diamine and a solvent to obtain a passivation layer precursor solution, and coating the passivation layer precursor solution to obtain a passivation layer.

4. The method according to claim 3, characterized in that The method has one or more of the following features: In the passivation layer precursor solution, the solvent is isopropanol and / or chlorobenzene; In the passivation layer precursor solution, the concentration of 5-bromo-2-(methylthio)pyrimidine-4,6-diamine is 5-10 mg / mL; The passivation layer precursor solution is coated by spin coating, blade coating or slit coating.

5. An inverted assembly, characterized in that: The inverted component comprises, in order from the thickness direction, a hole transport layer, a perovskite light absorption layer, the passivation layer according to claim 1, and an electron transport layer.

6. The inverted assembly according to claim 5, characterized in that: The inverted assembly has one or more of the following features: The perovskite light-absorbing layer comprises a perovskite structure material, the chemical formula of the perovskite structure material is ABX3, the A-position cation is selected from one or more of formamidinium ions, cesium ions and methylamine ions, the B-position cation is a lead ion, and the X-position anion is a bromide ion and / or an iodide ion; The thickness of the perovskite light absorbing layer is 400-500nm; The electron transport layer is C60 and / or fullerene derivatives; The thickness of the electron transport layer is 10-50 nm.

7. A method for preparing the inverted assembly according to claim 5 or 6, characterized in that: The method comprises the following steps: (1) depositing the perovskite light absorbing layer on the surface of the hole transport layer; (2) depositing the passivation layer on the surface of the perovskite light absorbing layer; (3) Depositing the electron transport layer on the surface of the passivation layer to obtain the inverted component.

8. The method according to claim 7, characterized in that In step (1), the raw material of the perovskite structure material and the solvent are mixed to obtain a perovskite precursor solution, and then the perovskite precursor solution is coated on the surface of the hole transport layer, and then annealed to obtain a perovskite light absorbing layer.

9. A perovskite solar cell comprising the inverted module according to claim 5 or 6.

10. Use of the passivation layer according to claim 1 or 2 in preparing a perovskite solar cell.

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