Passivation solution, passivation method and passivation layer for passivating surface of perovskite thin film

Abstract

The invention provides a passivation solution, a passivation method and a passivation layer for passivating the surface of a perovskite thin film. The passivation solution for passivating the surface of the perovskite thin film contains a metal organic framework material, hydrobromide of a diamine compound and a solvent, the particle size of the metal organic framework material is 30-50nm. The perovskite thin film is passivated by using the mixed solution of the hydrobromide containing the metal organic framework material and the diamine compound, so that surface and carrier recombination can be reduced and inhibited, the electron extraction capability is improved, and the open-circuit voltage and the fill factor are simultaneously improved.

Description

Technical Field

[0001] The present invention relates to the field of solar cells, and in particular to a passivation solution, a passivation method and a passivation layer for passivating the surface of a perovskite film. Background Art

[0002] Currently, in the field of solar cells, perovskite solar cells have become a research hotspot in the photovoltaic field due to their high photoelectric conversion efficiency and low preparation cost. In inverse perovskite solar cells, the most commonly used electron transport layer is an organic molecule based on fullerene (C60). However, defects and energy level mismatch at the perovskite / electron transport layer interface are one of the main reasons for the differences in open circuit voltage and device performance. Therefore, suppressing non-radiative recombination by optimizing the perovskite / C60 interface is of great significance for developing the potential of inverse structure (pin) perovskite solar cells.

[0003] In recent years, various methods have been used to improve the surface and interface of perovskites to enhance open-circuit voltage and fill factor. However, relying on a single type of molecule may not be able to simultaneously enhance open-circuit voltage and fill factor. Summary of the Invention

[0004] To address the aforementioned problems with the prior art, the present invention provides a passivation solution, passivation method, and passivation layer for passivating the surface of a perovskite film. By using a mixed solution containing a metal-organic framework material and a hydrobromide salt of a diamine compound to passivate the perovskite film, the present invention can reduce surface charge and carrier recombination, improve electron extraction, and simultaneously increase open-circuit voltage and fill factor.

[0005] Specifically, the first aspect of the present invention provides a passivation solution for passivating the surface of a perovskite film, wherein the passivation solution contains a metal organic framework material, a hydrobromide salt of a diamine compound, and a solvent; and the particle size of the metal organic framework material is 30-50 nm.

[0006] In one or more embodiments, the metal organic framework material includes IRMOFs and / or ZIFs materials.

[0007] In one or more embodiments, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0008] In one or more embodiments the solvent is selected from one or more of isopropanol, ethanol, and methanol.

[0009] In one or more embodiments, the chemical formula of IRMOFs is A x Zn 4-x OR3, wherein A is Fe and / or Mg, R is a dicarboxylic acid ligand, and x is 0 to 3.

[0010] In one or more embodiments, R is one or more of terephthalic acid, 2-aminoterephthalic acid, 2-bromoterephthalic acid, 2,5-diethyl terephthalic acid derivatives, 2,6-naphthalene dicarboxylate, biphenyl-4,4'-dicarboxylic acid, terphenyl-4,4"-dicarboxylic acid, 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, 2,6-naphthalene dicarboxylic acid, NH-CO-R'-BDC, 2-hydroxyterephthalic acid, 2-mercaptoterephthalic acid, Sal-BDC3, and 2,5-dihydroxyterephthalic acid groups; wherein R' is an amide modifying group, BDC is a terephthalic acid group, and Sal represents a salicylaldehyde amino derivative.

[0011] In one or more embodiments, the chemical formula of ZIFs is M(Im)2, wherein M is Zn 2+ and / or Co 2+ , Im is an imidazole ester ligand.

[0012] In one or more embodiments, the imidazole ester ligand is one or more of 2-methylimidazole, benzimidazole, and imidazole-2-carboxaldehyde.

[0013] In one or more embodiments, the mass content of the metal organic framework material in the passivation solution is 1-10 mg / mL.

[0014] In one or more embodiments, the mass content of the hydrobromide salt of the diamine compound in the passivation solution is 1-10 mg / mL.

[0015] In one or more embodiments, in the passivation solution, the mass ratio of the metal organic framework material to the hydrobromide of the diamine compound is (2-20):1.

[0016] A second aspect of the present invention provides a method for passivating the surface of a perovskite film or a method for preparing a perovskite passivation layer, the method comprising the following steps: applying a passivation solution for passivating the surface of a perovskite film as described in any embodiment of the present invention to the surface of the perovskite film, and annealing to obtain the perovskite passivation layer.

[0017] In one or more embodiments, the coating is performed by one or more processes selected from spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis, and slot coating.

[0018] In one or more embodiments, the annealing temperature is 80-100° C., and the annealing time is 2-10 minutes.

[0019] The third aspect of the present invention provides a perovskite passivation layer, which is arranged on the surface of the perovskite film. The perovskite passivation layer contains a metal organic framework material and a hydrobromide of a diamine compound, and the particle size of the metal organic framework material is 30-50 nm.

[0020] In one or more embodiments, the metal organic framework material is as described in any of the embodiments herein.

[0021] In one or more embodiments, the hydrobromide salt of the bisamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0022] In one or more embodiments, the mass ratio of the metal organic framework material to the hydrobromide salt of the diamine compound is (2-20):1.

[0023] A fourth aspect of the present invention provides a perovskite solar cell, comprising a substrate, a transparent conductive electrode, a hole transport layer, a perovskite thin film, a perovskite passivation layer as described in any embodiment of the present invention, an electron transport layer and an electrode arranged in sequence.

[0024] A fifth aspect of the present invention provides a use of the perovskite passivation layer as described in any embodiment herein in stabilizing a perovskite structure or preparing a perovskite solar cell.

[0025] In one or more embodiments, the metal organic framework material is as described in any of the embodiments herein.

[0026] In one or more embodiments, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0027] In one or more embodiments, the mass ratio of the metal organic framework material to the hydrobromide salt of the diamine compound is (2-20):1.

[0028] A sixth aspect of the present invention provides the use of a metal organic framework material and a hydrobromide of a diamine compound in the simultaneous passivation of the surface and interface of a perovskite film.

[0029] In one or more embodiments, the metal organic framework material is as described in any of the embodiments herein.

[0030] In one or more embodiments, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0031] In one or more embodiments, the mass ratio of the metal organic framework material to the hydrobromide salt of the diamine compound is (2-20):1.

[0032] A seventh aspect of the present invention provides the use of a metal organic framework material and a hydrobromide of a diamine compound in preparing a passivation layer of a perovskite film.

[0033] In one or more embodiments, the metal organic framework material is as described in any of the embodiments herein.

[0034] In one or more embodiments, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0035] In one or more embodiments, the mass ratio of the metal organic framework material to the hydrobromide salt of the diamine compound is (2-20):1.

[0036] An eighth aspect of the present invention provides the use of a metal organic framework material and a hydrobromide salt of a diamine compound in preparing a perovskite solar cell with improved open circuit voltage and fill factor.

[0037] In one or more embodiments, the metal organic framework material is as described in any of the embodiments herein.

[0038] In one or more embodiments, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0039] In one or more embodiments, the mass ratio of the metal organic framework material to the hydrobromide salt of the diamine compound is (2-20):1.

[0040] Beneficial effects of the present invention:

[0041] The present invention passivates the perovskite film by using a mixed solution containing a metal organic framework material and a hydrobromide of a diamine compound. The MOF material forms uniformly dispersed contacts on the surface of the perovskite film, forming a channel for charge transmission; the hydrobromide of the diamine compound is used to passivate surface defects. The combination of the two can provide an optimal trade-off between passivation and charge extraction. The double passivation method can reduce the surface and inhibit carrier recombination, improve the electron extraction ability, and achieve a simultaneous increase in open circuit voltage and fill factor. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 Schematic diagram of the structure of the inverted perovskite solar cell according to Example 1 of the present invention. DETAILED DESCRIPTION

[0043] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used herein. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art with respect to the present invention. In the event of conflict, the definitions herein shall prevail.

[0044] 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.

[0045] 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 have been disclosed herein.

[0046] Throughout this document, all features, such as values, amounts, amounts, and concentrations, specified in numerical ranges or percentage ranges are provided for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to encompass and specifically disclose all possible subranges and individual values ​​within those ranges (including integers and fractions).

[0047] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0048] Herein, when describing embodiments or examples, it should be understood that they are not intended to limit the present invention to these embodiments or examples. On the contrary, all alternatives, modifications and equivalents of the methods and materials described herein are encompassed within the scope defined by the claims.

[0049] In this document, for the sake of brevity, not all possible combinations of the various technical features in each embodiment or example are described. Therefore, as long as there are no contradictions in the combination of these technical features, the various technical features in each embodiment or example can be combined in any way, and all possible combinations should be considered to be within the scope of this specification.

[0050] The purpose of the present invention is to provide a passivation solution, a passivation method and a passivation layer for passivating the surface of a perovskite film. The present invention passivates the perovskite film by using a mixed solution containing a metal organic framework material (MOF material) and a hydrobromide salt of a diamine compound, thereby achieving efficient electron extraction and further suppressing non-radiative recombination. The MOF material forms uniformly dispersed contacts on the surface of the perovskite film. Such nanomaterials can form an open channel, which is conducive to charge transfer. In addition, the organic ligands in the MOF material, such as carbonyl and amino groups and oxygen sites, can effectively react with metal ions such as Pb in the perovskite. 2+ and halide ions such as I - etc. to establish coordination, thereby being able to passivate excess metal ions such as Pb 2+ At the same time, by using MOF materials to separate the contact distance between perovskite and electron transport layer such as C60 layer, the non-radiative recombination loss between fullerene and perovskite is reduced. The hydrobromide molecules of diamine compounds can chemically passivate the surface of perovskite, and the amino groups in them react with metal ions such as Pb in perovskite. 2+ The hydrobromide molecules of the diamine compound coordinate with each other and are distributed within the channels formed by the MOF material. Therefore, the MOF material forms a channel for charge transfer, and the hydrobromide of the diamine compound is used to passivate surface defects. The combination of the two can provide an optimal trade-off between passivation and charge extraction. This dual passivation method can reduce surface and inhibit carrier recombination, thereby improving electron extraction capability.

[0051] In the present invention, MOF materials are short for metal-organic framework materials, which are crystalline porous materials formed by self-assembly of inorganic metal centers (metal ions or metal clusters) and organic ligands through coordination bonds. In some embodiments, MOF materials include IRMOFs (repeating network MOFs) materials and / or ZIFs (zeolitic imidazolate framework materials).

[0052] In the present invention, the particle size of the MOF material is 30-50 nm.

[0053] In the present invention, IRMOFs are mainly formed by [Zn4O6] + The metal clusters are bonded to the carboxylic acid organic ligands to form a repeating network topology. The chemical formula of IRMOFs can be A x Zn 4-x OR3, R is a dicarboxylic acid ligand, and x is 0 to 3. In some embodiments, A is Fe and / or Mg. In some embodiments, R is a terephthalic acid group (BDC, C8H4O4 2- ), 2-aminoterephthalic acid (NH2-BDC, C8H5NO4 2- ), Br-BDC (2-bromoterephthalic acid, C8H3BrO4 2-), BDC-EE (2,5-diethyl terephthalic acid derivative), NDC (2,6-naphthalene dicarboxylate, chemical formula C 12 H6O4 2- ), BPDC (biphenyl-4,4'-dicarboxylic acid, C 14 H8O4 2- ), TPDC (terphenyl-4,4"-dicarboxylic acid, C 20 H 12 O4 2- ), H4TBAPy (1,3,6,8-tetrakis (4-carboxyphenyl) pyrene), 2,6-naphthalenedicarboxylic acid (NDC), NH-CO-R'-BDC (R' is an amide modification group), HO-BDC (2-hydroxyterephthalic acid, C8H4O5 2- ), HS-BDC (2-mercaptoterephthalic acid, C8H4O4S 2 -), Sal-BDC3 (Sal represents salicylaldehyde amino derivative) and DOT (2,5-dihydroxyterephthalic acid, C8H4O6 2- )

[0054] In some embodiments, IRMOFs are selected from IRMOF-1 (Zn4O(BDC)3), IRMOF-3 (Zn4O(NH2-BDC)3), IRMOF-4 (Zn4O(Br-BDC)3), IRMOF-8 (Zn4O(BDC-EE)3), IRMOF-9 (Zn4O(NDC)3), IRMOF-10 (Zn4O(BPDC)3), IRMOF-11, IRMOF-12, IRMOF-13, IRMOF-14, IRMOF-16 (Zn4O(TPDC)3), IRMOF-18 (Zn4O(H4TBAPy)3), IRMOF-61, IRMOF-62, IRMOF-3-AM1 (Zn4O(NH-CO-R-BDC)3), Fe / IRMOF-3 (Fe x Zn 4-x O(NH2-BDC)3), Mg-IRMOF-74(Mg2(DOT)), IRMOF-3-OH(Zn4O(HO-BDC)3), IRMOF-3-SH(Zn4O(HS-BDC)3), Fe / IRMOF-3-900 (amorphous Fe / C composite material, the MOF structure collapses after high-temperature pyrolysis, and there is no clear chemical formula) and IRMOF3-sal(Zn4O(Sal-BDC)3).

[0055] In the present invention, ZIFs materials are self-assembled by Zn or Co and N on the imidazole (or imidazole derivative) ring in a four-coordinated manner. The chemical formula of ZIFs can be M(Im)2, where M is Zn 2+ and / or Co 2+ , Im is an imidazole ester ligand. In some embodiments, the imidazole ester ligand Im is mIm (2-methylimidazole, C4H5N2 - ), bIm(benzimidazole, C7H5N2 - ) and ica(imidazole-2-carboxaldehyde, C4H3N2O - )

[0056] In some specific embodiments, the ZIFs material is selected from ZIF-1 (Zn(Im)2, simple topology), ZIF-2 (Zn(Im)2, the same ligand as ZIF-1, different structure), ZIF-4 (Zn(Im)2, sodalite (SOD) topology), ZIF-5 (Zn(bIm)2, extended ligand), ZIF-7 (Zn(bIm)2, high chemical stability), ZIF-8 (Zn(mIm)2, SOD topology), ZIF-9 (Co(bIm)2), ZIF-10 (Zn(nIm)2), ZIF-11 (Zn(bIm)2, RHO topology), ZIF-12 (Zn(bIm)2, the same ligand as ZIF-11, different structure), ZIF-14, ZIF-20, ZIF-23, ZIF-60 (Zn(mIm)2, SOD topology), ZIF-7 (Zn(bIm)2, extended ligand ...7 (Zn(bIm)2, high chemical stability), ZIF-8 (Zn(mIm)2, SOD topology), ZIF-7 (Zn(bIm)2, Co(bIm)2), ZIF-7 (Zn(bIm)2, SOD topology), ZIF-7 (Zn 1.5 (tbIm) 0.5 )、ZIF-61(Zn(mIm) 1.25 (eIm) 0.75 )、ZIF-62(Zn(mIm) 1.75 (bIm) 0.25 ), ZIF-64(Zn(pIm)2), ZIF-65(Zn(cIm)2), ZIF-67, ZIF-68(Zn(nIm)(mIm)), ZIF-69(Zn(pIm)(mIm)), ZIF-70(Zn(mIm) 1.6 (eIm) 0.4 ), ZIF-71(Zn(dIm)2), ZIF-72, ZIF-73, ZIF-74, ZIF-75, ZIF-77, ZIF-78, ZIF-90(Zn(ica)2 ), one or more of ZIF-95(Zn(bIm)2), ZIF-100(Zn(mIm)2), ZIF-224, ZIF-268, Zn / Co-ZIF and nZIF-8.

[0057] In the present invention, the hydrobromide of a diamine compound refers to a salt formed by an organic molecule containing two amino groups (-NH2, -NHR or -NR2) and hydrobromic acid (HBr). The hydrobromide of a diamine compound includes, but is not limited to, ethylenediamine dihydrobromide, 2,2'-(ethylenedioxy)bisethylamine hydrobromide, and the like. In some embodiments, the hydrobromide of a diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide.

[0058] In the present invention, the chemical formula structure of 2,2'-(ethylenedioxy)bisethylamine hydrobromide (EDBEBr2) is shown in Formula 1 below:

[0059]

[0060] In some embodiments, the mass content of the MOF material in the passivation solution is 1-10 mg / mL, such as 1-5 mg / mL.

[0061] In some embodiments, the mass content of the hydrobromide salt of the diamine compound in the passivation solution is 1-10 mg / mL, such as 1-5 mg / mL.

[0062] In some embodiments, in the passivation solution, the mass ratio of the MOF material to the hydrobromide of the diamine compound is (2-20):1.

[0063] In some embodiments, the passivation solution further comprises a solvent. Preferably, the solvent can be selected from one or more of isopropanol, ethanol and methanol.

[0064] In the present invention, the active material of the perovskite film contains an ABX3 compound, wherein A is a monovalent cation, such as a mixture of one or more monovalent cations selected from cesium, rubidium, methylamino, and guanidine; B is a divalent cation, such as a mixture of one or more divalent cations selected from lead, copper, zinc, gallium, tin, and calcium; and X is a monovalent anion, such as a mixture of one or more monovalent anions selected from iodine, bromine, chlorine, fluorine, and thiocyanate. In some preferred embodiments, the active material of the perovskite film is selected from CsFAPbI3, MAPbI3, CsPbI3, and Cs x FA 1-x Pb(I y Br 1-y )3, wherein x is 0.05-0.3 and y is 0.5-1.0.

[0065] The perovskite passivation layer of the present invention is obtained by coating a passivation solution containing the above-mentioned MOF material and hydrobromide of a diamine compound on the surface of a perovskite film (perovskite absorption layer) and annealing the solution.

[0066] In some embodiments, the method for preparing the perovskite passivation layer of the present invention comprises the following steps:

[0067] S1. providing a passivation solution for passivating the perovskite surface, which contains a MOF material, a hydrobromide salt of a diamine compound, and a solvent;

[0068] S2. Coating a passivation solution on the surface of the perovskite film using a solution method, and annealing to obtain a perovskite passivation layer.

[0069] In step S1, the solvent may be selected from one or more of isopropanol, ethanol and methanol.

[0070] In step S2, the coating method can be one or more processes selected from spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis, and slot coating. The coating thickness and coating rate of the passivation solution can be adjusted according to the target thickness of the perovskite passivation layer.

[0071] In step S2, the annealing temperature may be 80-100° C., and the annealing time may be 2-10 minutes.

[0072] Therefore, the present invention provides a perovskite passivation layer, which is arranged on the surface of the perovskite film. The perovskite passivation layer contains a metal organic framework material and a hydrobromide of a diamine compound.

[0073] The metal organic framework material and the hydrobromide of the diamine compound in the passivation layer are respectively as described above.

[0074] In some embodiments, the mass ratio of the metal organic framework material to the hydrobromide of the diamine compound in the passivation layer is (2-20):1.

[0075] The present invention also provides a method for preparing a perovskite solar cell, which includes the steps of sequentially arranging a hole transport layer, a perovskite light absorption layer (perovskite film), a perovskite passivation layer, an electron transport layer and an electrode on a conductive substrate, wherein the perovskite passivation layer can be prepared using the method for preparing the perovskite passivation layer described herein.

[0076] The present invention also provides a perovskite solar cell, which comprises the perovskite passivation layer as described herein.

[0077] In some embodiments, the perovskite solar cell of the present invention includes a substrate, a transparent conductive electrode, a hole transport layer, a perovskite absorption layer (perovskite thin film), the perovskite passivation layer described herein, an electron transport layer, and an electrode, which are arranged in sequence.

[0078] The substrate material applicable to the present invention may be a conventional substrate material used in the art for preparing perovskite solar cells, such as a transparent glass substrate.

[0079] The transparent conductive electrode material suitable for the present invention can be selected from ITO or FTO. The preparation of the transparent conductive electrode is not particularly limited in the present invention and can be prepared using conventional methods in the art, such as magnetron sputtering to deposit it on a substrate surface. Process parameters can be adjusted based on the target thickness of the conductive oxide layer. In some embodiments, the thickness of the transparent conductive electrode is 80 nm to 120 nm.

[0080] The material of the hole transport layer suitable for the present invention can be selected from one or both of nickel oxide and self-assembled monolayer. In some embodiments, the material of the self-assembled monolayer is selected from one or more of poly[triphenylamine-alternating-3,6-carbazole] (PTAA), poly(3,4-ethylenedioxythiophene) (PEDOT), polystyrene sulfonate (PSS), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid. The preparation of the hole transport layer is not particularly limited, and the conventional method for preparing the hole transport layer in the art can be adopted, such as the process of magnetron sputtering. The process parameters can be adjusted according to the target thickness of the hole transport layer. In some embodiments, the thickness of the hole transport layer is 10nm-30nm.

[0081] The active material of the perovskite absorption layer suitable for the present invention contains an ABX3 compound, wherein A is a monovalent cation, such as a mixture of one or more monovalent cations selected from cesium, rubidium, methylamino, and formamidinium; B is a divalent cation, such as a mixture of one or more divalent cations selected from lead, copper, zinc, gallium, tin, and calcium; and X is a monovalent anion, such as a mixture of one or more monovalent anions selected from iodine, bromine, chlorine, fluorine, and thiocyanate. In some embodiments, the material of the perovskite absorption layer is selected from CsFAPbI3, MAPbI3, CsPbI3, and Cs x FA 1-x Pb(I y Br 1-y ) 3. The preparation of the perovskite absorber layer is not particularly limited and can be prepared using conventional methods in the art, including but not limited to one or more of spin coating, doctor blade coating, evaporation, printing, spray coating, spray pyrolysis, and slot coating. The process parameters can be adjusted according to the target thickness of the perovskite absorber layer. In some embodiments, the thickness of the perovskite absorber layer is 300-600 nm.

[0082] Materials suitable for the electron transport layer of the present invention include, but are not limited to, one or more of C60, TiO2, ZnO, WO3, SnO2, Zn2SnO4, IZO, fullerene, and derivatives thereof. The preparation of the electron transport layer is not particularly limited, and conventional methods for preparing the electron transport layer in the art may be used, including but not limited to one or more of spin coating, spray coating, spray pyrolysis, slit coating, and atomic layer deposition. The process parameters may be adjusted according to the target thickness of the electron transport layer. In some embodiments, the thickness of the electron transport layer is 10 nm to 30 nm. In some embodiments, the electron transport layer comprises a C60 layer, a SnO2 layer, and an IZO layer. The thickness of the C60 layer is 10-20 nm; the thickness of the SnO2 layer is 10-15 nm, and the thickness of the IZO layer is 30-60 nm.

[0083] The material of the electrode suitable for the present invention can be selected from one or more of copper, aluminum and silver. In some embodiments, the thickness of the electrode is 90 nm to 400 nm.

[0084] The present invention will be described below by way 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 starting compounds in the examples can all be purchased from commercial sources.

[0085] Example 1:

[0086] 1. 100nm ITO transparent electrode was prepared by magnetron sputtering.

[0087] 2. A 15nm NiOx hole transport layer was prepared by magnetron sputtering.

[0088] 3. Prepare 500nm perovskite layer by coating method: configure 1.8mol / L concentration of Cs 0.22 FA 0.78 Pb(I 0.85 Br 0.15 ) 3 was dissolved in DMF / NMP (v:v = 85:15) and coated at a rate of 20 mm / s. Excess solvent was then removed using a wind knife at a speed of 20 m / s until the film turned dark yellow. Annealing at 120°C for 20 min yielded the perovskite absorber layer.

[0089] 4. Prepare the passivation layer using a slot-coating method: Mix 30 nm ZIF-8 particles, 2,2'-(ethylenedioxy)bisethylamine hydrobromide (EDBEBr2), and isopropyl alcohol (IPA) to obtain a passivation solution. The ZIF-8 concentration is 1 mg / mL, and the EDBEBr2 concentration is 0.5 mg / mL. The perovskite absorber layer is passivated using this mixed passivation solution with an injection rate of 30 μL / s, a coating speed of 30 mm / s, and a gap of 100 μm. The passivation layer is then annealed at 100°C for 10 minutes to obtain the passivation layer.

[0090] 5. The electron transport layer was prepared by vacuum evaporation method: 15nm C60 / 15nm SnO2 / 50nm indium-doped tin oxide (IZO).

[0091] 6. Prepare 400nm silver electrode by vacuum evaporation method.

[0092] Perovskite solar cells are prepared as Figure 1 shown.

[0093] Example 2:

[0094] The difference from Example 1 is that ZIF-8 is replaced by ZIF-9 in step 4. The remaining operating conditions and steps are the same as those in Example 1.

[0095] Example 3:

[0096] The difference from Example 1 is that ZIF-8 is replaced by ZIF-67 in step 4. The remaining operating conditions and steps are the same as those in Example 1.

[0097] Example 4:

[0098] The difference from Example 1 is that ZIF-8 is replaced by IRMOF-1 in step 4. The remaining operating conditions and steps are the same as those in Example 1.

[0099] Example 5:

[0100] The difference from Example 1 is that ZIF-8 is replaced by IRMOF-3 in step 4. The remaining operating conditions and steps are the same as those in Example 1.

[0101] Example 6

[0102] The difference from Example 1 is that in step 4, the mass concentration of ZIF-8 is 10 mg / mL. The remaining operating conditions and steps are the same as those in Example 1.

[0103] Example 7

[0104] The difference from Example 5 is that in step 4, the mass concentration of IRMOF-3 is 10 mg / mL. The remaining operating conditions and steps are the same as those in Example 5.

[0105] Example 8

[0106] The difference from Example 5 is that in step 4, the particle size of the ZIF-8 material is 50 nm.

[0107] Comparative Example 1:

[0108] The difference from Example 1 is that in step 4, the particle size of the ZIF-8 material is 60 nm. The remaining operating conditions and steps are the same as those in Example 1.

[0109] Comparative Example 2:

[0110] The difference from Example 1 is that in step 4, the particle size of the ZIF-8 material is 20 nm. The remaining operating conditions and steps are the same as those in Example 1.

[0111] Comparative Example 3:

[0112] The difference from Example 1 is that in step 4, EDBEBr2 is replaced by phenethylammonium iodide molecule. The remaining operating conditions and steps are the same as those in Example 1.

[0113] Test Example 1

[0114] The perovskite solar cells prepared in Examples 1-7 and Comparative Examples 1-3 were subjected to photoelectric testing, where the test light intensity was AM1.5G standard light intensity and the test temperature was 25±1°C.

[0115] Open circuit voltage V OC is the terminal voltage of the battery in the open circuit state. SC The fill factor (FF) is the current density a perovskite solar cell can generate under short-circuit conditions. The fill factor (FF) is the ratio of the solar cell's maximum power to the product of its open-circuit voltage and short-circuit current. The PCE (power conversion efficiency) can be calculated by measuring the solar cell's current density-voltage curve (J-V curve).

[0116] The results are shown in Table 1 below:

[0117] Table 1. Photoelectric test results

[0118]

[0119] From the results of Examples 1-7 and Comparative Examples 1-2, it can be seen that Examples 1-7 significantly improve the open circuit voltage, fill factor and photoelectric conversion efficiency of the device by selecting MOFs materials with a particle size of 30-50 nm.

[0120] Compared with Comparative Example 3, Examples 1-7 improve the open circuit voltage, fill factor and photoelectric conversion efficiency of the device by selecting the hydrobromide of a diamine compound such as EDBEBr2 and combining it with MOFs materials.

Claims

1. A passivation solution for passivating the surface of a perovskite film, characterized in that: The passivation solution contains a metal organic framework material, a hydrobromide of a diamine compound and a solvent; wherein the particle size of the metal organic framework material is 30-50 nm.

2. The passivation solution according to claim 1, wherein: The metal organic framework material includes IRMOFs and / or ZIFs materials; and / or The hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide; and / or The solvent is selected from one or more of isopropanol, ethanol and methanol.

3. The passivation solution according to claim 2, wherein The chemical formula of IRMOFs is A x Zn 4-x OR3, wherein A is Fe and / or Mg, R is a dicarboxylic acid ligand, and x is 0 to 3.

4. The passivation solution according to claim 3, wherein R is one or more of terephthalic acid, 2-aminoterephthalic acid, 2-bromoterephthalic acid, 2,5-diethyl terephthalic acid derivatives, 2,6-naphthalene dicarboxylate, biphenyl-4,4'-dicarboxylic acid, terphenyl-4,4"-dicarboxylic acid, 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene, 2,6-naphthalene dicarboxylic acid, NH-CO-R'-BDC, 2-hydroxyterephthalic acid, 2-mercaptoterephthalic acid, Sal-BDC3 and 2,5-dihydroxyterephthalic acid groups; wherein R' is an amide modification group, BDC is a terephthalic acid group, and Sal represents a salicylaldehyde amino derivative.

5. The passivation solution according to claim 2, wherein The chemical formula of ZIFs is M(Im)2, where M is Zn 2+ and / or Co 2+ , Im is an imidazole ester ligand.

6. The passivation solution according to claim 5, wherein The imidazole ester ligand is one or more of 2-methylimidazole, benzimidazole and imidazole-2-carboxaldehyde.

7. The passivation solution according to claim 1, wherein The method has one or more of the following characteristics: In the passivation solution, the mass content of the metal organic framework material is 1-10 mg / mL; In the passivation solution, the mass content of the hydrobromide of the diamine compound is 1-10 mg / mL; In the passivation solution, the mass ratio of the metal organic framework material to the hydrobromide of the diamine compound is (2-20):

1.

8. A method for passivating the surface of a perovskite film or a method for preparing a perovskite passivation layer, characterized in that: The method comprises the following steps: coating the passivation solution for passivating the surface of a perovskite film according to any one of claims 1 to 7 on the surface of the perovskite film, and annealing to obtain a perovskite passivation layer.

9. The method according to claim 8, wherein The coating method is one or more processes selected from spin coating, blade coating, evaporation, printing, spray coating, spray pyrolysis and slot coating; and / or The annealing temperature is 80-100° C., and the annealing time is 2-10 minutes.

10. A perovskite passivation layer, characterized in that: The perovskite passivation layer is arranged on the surface of the perovskite film, and the perovskite passivation layer contains a metal organic framework material and hydrobromide of a diamine compound, and the particle size of the metal organic framework material is 30-50 nm.

11. The perovskite passivation layer according to claim 10, wherein The method has one or more of the following characteristics: The metal organic framework material as claimed in any one of claims 2 to 6; The hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide; The mass ratio of the metal organic framework material to the hydrobromide of the diamine compound is (2-20):

1.

12. A perovskite solar cell, characterized in that: The perovskite solar cell comprises a substrate, a transparent conductive electrode, a hole transport layer, a perovskite film, the perovskite passivation layer according to claim 10 or 11, an electron transport layer and an electrode, which are arranged in sequence. 13.Select from the following applications: (1) Use of the perovskite passivation layer according to claim 10 or 11 in stabilizing the perovskite structure or preparing a perovskite solar cell; (2) Application of metal organic framework materials and hydrobromide salts of diamine compounds in the simultaneous passivation of the surface and interface of perovskite films; (3) Application of metal organic framework materials and hydrobromide salts of diamine compounds in the preparation of perovskite film passivation layers; (4) Application of metal-organic framework materials and hydrobromide salts of diamine compounds in the preparation of perovskite solar cells with improved open circuit voltage and fill factor; Preferably, the metal organic framework material is as described in any one of claims 2 to 6; Preferably, the hydrobromide of the diamine compound is 2,2'-(ethylenedioxy)bisethylamine hydrobromide; Preferably, the mass ratio of the metal organic framework material to the hydrobromide of the diamine compound is (2-20):1.

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