Perovskite thin film and preparation method thereof, perovskite solar cell and preparation method thereof

Abstract

The invention discloses a perovskite thin film, a preparation method of the perovskite thin film, a perovskite solar cell and a preparation method of the perovskite solar cell, and the preparation method of the perovskite thin film comprises the following steps: depositing a perovskite precursor deposition solution on a first carrier transport layer, a preset amount of metal pseudo halide first solution is introduced in the perovskite thin film deposition process for co-deposition with the perovskite thin film, first annealing is performed after deposition is completed, and a perovskite light absorption layer is obtained. According to the invention, a metal pseudo-halide material is introduced into the film forming process of the perovskite film and the surface of the perovskite film, so that the purposes of regulating and controlling the crystallization process of the perovskite film, improving the crystallization quality of the perovskite film, increasing the grain size of the perovskite, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies and inhibiting migration of halogen ions are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of solar cells, and in particular relates to a perovskite film and a preparation method thereof, a perovskite solar cell and a preparation method thereof. Background Art

[0002] At present, with the acceleration of the pace of social modernization, the "energy crisis" and environmental pollution caused by the burning of fossil energy have also arisen. It is imperative to expand renewable and environmentally friendly new energy. The "inexhaustible" solar energy is the cleanest energy and is easy to obtain, which is crucial to the sustainable development of society. The development of low-cost, high-efficiency new photovoltaic cells is an effective means to solve the current energy problem. At present, crystalline silicon solar cells dominate the market, but limited by the characteristics of crystalline silicon materials, the theoretical conversion efficiency of crystalline silicon cells is 29.4%. In order to break through this efficiency limit, researchers have selected a new type of perovskite material with a wide bandgap and a narrow bandgap crystalline silicon material to construct a new type of perovskite / crystalline silicon tandem solar cell that can fully utilize the energy of the solar spectrum, with a theoretical conversion efficiency of more than 42%. However, due to the ionic crystal structure and fast crystallization process of the wide bandgap perovskite material, the prepared perovskite film has a large number of defects and is prone to halogen ion migration, resulting in poor device stability, which limits the further improvement of the efficiency of the perovskite / crystalline silicon tandem cell.

[0003] At present, researchers usually use the strategy of introducing additives into the perovskite precursor solution to regulate the crystallization process of perovskite materials and treat the surface of the perovskite film to passivate the surface defect states. However, the above methods mainly focus on single halogen perovskite materials, and the effect on mixed halogen perovskite materials is not obvious. Secondly, the strategy of introducing additives into the perovskite precursor will have an adverse effect on the nucleation process of the perovskite material. Some materials that have been proven to be able to passivate the defects of the perovskite film will accelerate the nucleation rate of the perovskite material, thereby reducing the grain size of the perovskite film. Finally, there are differences between the additive materials of the perovskite precursor and the surface passivation materials of the perovskite film, which undoubtedly makes the preparation process of perovskite solar cells more complicated and is not conducive to its industrial development. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a perovskite film and a preparation method thereof, a perovskite solar cell and a preparation method thereof in view of the above-mentioned deficiencies in the prior art, so as to further improve the performance of the perovskite solar cell.

[0005] The purpose of the present invention is to overcome the problems that the crystallization process of perovskite materials is difficult to control, the film quality is low, the defect density is high, the halogen ion escape stoichiometric ratio is unbalanced during the annealing process of the perovskite film, and the carrier migration phenomenon is serious during the operation of the device, which are caused by the ionic crystal structure of the perovskite material, the fast crystallization rate and the difference in crystallization rate between different components. A preparation method of a perovskite film is provided, and a metal pseudo-halogen compound material is introduced into and on the surface of the perovskite film during the coating process of the perovskite film, so as to achieve the purpose of slowing down the perovskite crystal growth rate, increasing the grain size of the perovskite film, filling the halogen vacancy defects in the perovskite lattice and on the surface of the film, blocking the halogen migration path, and inhibiting the migration of halogen ions while keeping the perovskite nucleation rate unchanged.

[0006] The method for preparing the perovskite light absorbing layer comprises preparing a perovskite precursor deposition liquid, coating the perovskite precursor deposition liquid on a substrate, dropping a solution added with a metal pseudohalide on the coating layer during the coating process, continuing the coating, and then annealing the perovskite film to obtain the perovskite light absorbing layer.

[0007] Compared with the traditional method of blending metal pseudohalides with perovskite precursor solutions, the traditional technology will accelerate the nucleation rate of perovskite, thereby causing insufficient crystallization of the perovskite film and adversely affecting the crystallinity of the perovskite film. The present application provides a technology that introduces metal pseudohalides during the coating process of the perovskite film, which can slow down the growth rate of the perovskite crystal without affecting the nucleation rate of the perovskite, provide sufficient growth conditions for the perovskite crystal growth process, and thus improve the crystallinity of the perovskite film.

[0008] In the technical solution described in the present application, the mass fraction of the introduced metal pseudo-halide compound is negligible for the perovskite as a whole, and the metal ions in the pseudo-halide metal compound partially replace or fill the defects in the perovskite crystal structure. In this process, the overall crystal structure properties of the perovskite do not change.

[0009] The crystallization process of perovskite materials is divided into two parts: nucleation and growth. The nucleation process occurs at the beginning of the supersaturated state of the perovskite precursor solution, and the process is very rapid, while the growth process is from the nucleus to small grains and then to large grains. Properly delaying these two processes is conducive to the growth of high-quality perovskite crystals. However, in the nucleation process, a lower ionic radius will increase the nucleation rate, resulting in a reduction in the size of the perovskite grains, which is not conducive to the formation of high-quality perovskite films.

[0010] In the technical solution, the metal pseudohalide is introduced during the perovskite coating process. The introduction of the metal pseudohalide during the coating process effectively avoids the nucleation process of the perovskite crystal in the initial coating of the perovskite film. For example, during the spin coating process, part of the solution system has reached an oversaturated state to produce nucleation, and the application of solvents such as chlorobenzene will accelerate this oversaturation process. The introduction of the metal pseudohalide in this step can avoid its influence on the nucleation process and affect the subsequent crystal growth process. Among them, the divalent metal cation (such as Cd 2+ ) and pseudohalide anions (such as SCN - ) will be with [PbX6] 4- The regular octahedral structures interact with each other, thereby slowing down the crystal growth rate of perovskite grains. This ultimately forms a slow crystal growth process, which is beneficial to increasing the perovskite grain size and enhancing the crystallinity of the perovskite film.

[0011] The technical solution adopted to solve the technical problem of the present invention is to provide a method for preparing a perovskite film, comprising the following steps:

[0012] The perovskite precursor deposition liquid is deposited on the first carrier transport layer, and a preset amount of a metal pseudohalide first solution is introduced during the perovskite film deposition process to be co-deposited with the perovskite film. After the deposition is completed, a first annealing is performed to obtain a perovskite light absorbing layer.

[0013] The perovskite film includes a perovskite light absorbing layer.

[0014] Preferably, the metal pseudohalide in the first metal pseudohalide solution has a general structural formula of RY2, wherein R is an ionic radius smaller than that of Pb 2+ divalent metal cations and capable of forming chemical bonds with the perovskite X-site halogen anions, wherein R comprises a cadmium ion (Cd 2+ ), strontium ion (Sr 2+ ), palladium ions (Pd 2+ ), cobalt ions (Co 2+ ), zinc ion (Zn 2+ ), copper ions (Cu 2+ ), nickel ions (Ni 2+ ) any one or more of;

[0015] Y is a pseudohalide anion, Y includes thiocyanate (SCN - ), cyanide (CN - ), cyanate (OCN - ), hypothiocyanate (OSCN - ), selenocyanate (SeCN - ), azide (N3 - ), nitrite (NO2 - ), formate (HCOO- ), acetate (CH3COO - ), propionate (CH3CH2COO - ), butyrate (CH3(CH2)2COO - ), valerate (CH3(CH2)3COO - ), hexanoate (CH3(CH2)4COO - ) any one or more of them.

[0016] Preferably, the concentration of the first metal pseudo-halide solution is 0.3-0.8 mg / mL, the solvent in the first metal pseudo-halide solution is chlorobenzene and isopropanol, and the volume ratio of chlorobenzene to isopropanol is (8-10):1.

[0017] Preferably, the first annealing is annealing at 55-65° C. for 1-5 min, and then annealing at 100-140° C. for 5-18 min.

[0018] Preferably, the thickness of the perovskite light absorbing layer is 300-800 nm.

[0019] Preferably, the method for preparing the perovskite film further comprises the following steps:

[0020] The second metal pseudo-halide solution is deposited on the perovskite light absorbing layer, and a second annealing is performed to obtain an interface layer.

[0021] The perovskite film further includes an interface layer disposed on the perovskite light absorbing layer.

[0022] Preferably, the concentration of the second metal pseudo-halide solution is 0.1-3 mg / mL, and the solvent in the second metal pseudo-halide solution is any one of ethanol, isopropanol, toluene, chlorobenzene, chloroform, and ether.

[0023] The metal pseudohalide in the second solution of metal pseudohalide has a general structural formula of RY2, wherein R is an ionic radius smaller than that of Pb 2+ divalent metal cations and capable of forming chemical bonds with the perovskite X-site halogen anions, wherein R comprises a cadmium ion (Cd 2+ ), strontium ion (Sr 2+ ), palladium ions (Pd 2+ ), cobalt ions (Co 2+ ), zinc ion (Zn 2+ ), copper ions (Cu 2+ ), nickel ions (Ni 2+ ) any one or more of;

[0024] Y is a pseudohalide anion, Y includes thiocyanate (SCN - ), cyanide (CN -), cyanate (OCN - ), hypothiocyanate (OSCN - ), selenocyanate (SeCN - ), azide (N3 - ), nitrite (NO2 - ), formate (HCOO - ), acetate (CH3COO - ), propionate (CH3CH2COO - ), butyrate (CH3(CH2)2COO - ), valerate (CH3(CH2)3COO - ), hexanoate (CH3(CH2)4COO - ) any one or more of them.

[0025] Preferably, the second annealing temperature is 60-100° C. and the time is 3-15 min.

[0026] Preferably, the thickness of the interface layer is 1 to 20 nm.

[0027] The present invention also provides a perovskite film, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the above method.

[0028] The material of the perovskite light-absorbing layer is an ABX3 perovskite light-absorbing material doped with a metal pseudohalide, wherein A includes CH3NH3 + 、CH(NH2)2 + 、(CH3)2NH2 + , Cs + Any one or more of; B includes Pb 2+ Sn 2+ Any one or two of; X is a halogen ion I - Br - , Cl - Any one or more of the following. Among them, CH3NH3 + (methylamine ion, MA + )、(CH3)2NH2 + (dimethylammonium ion, DMA + )、CH(NH2)2 + (Formamidinium ion, FA + ).

[0029] The present invention also provides a perovskite solar cell, comprising a conductive substrate, a first carrier transport layer, a perovskite light absorption layer, an interface layer, a second carrier transport layer, a buffer layer, and an electrode layer arranged in sequence, wherein the perovskite light absorption layer is the perovskite light absorption layer obtained by the above-mentioned preparation method.

[0030] Preferably, the conductive substrate includes any one of ITO, FTO and AZO.

[0031] Preferably, the first carrier transport layer is a first hole transport layer, and the second carrier transport layer is a first electron transport layer;

[0032] The first carrier transport layer is a second electron transport layer, and the second carrier transport layer is a second hole transport layer.

[0033] Preferably, the material of the first hole transport layer or the second hole transport layer is [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid (4PADCB), [2-(9H-carbazole-9-yl)ethyl]phosphoric acid (2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid (Me-4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid ( MeO-2PACz), 2,2',7,7'-tetrakis[N,N-di(4-methylphenyl)amino]-9,9'-spirobifluorene (Spiro-TTB), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD), nickel oxide (NiO x ), cuprous thiocyanate (CuSCN), copper iodide (CuI).

[0034] Preferably, the material of the first electron transport layer or the second electron transport layer includes C 60 ,[6,6]-phenyl-C 61 - any one of methyl butyrate (PCBM), tin oxide (SnO2), zinc oxide (ZnO), and titanium oxide (TiO2).

[0035] Preferably, the thickness of the first carrier transport layer is 1 to 100 nm, and the thickness of the second carrier transport layer is 1 to 100 nm.

[0036] Preferably, the material of the buffer layer is SnO2 or 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP);

[0037] The thickness of the buffer layer is 2 to 10 nm.

[0038] Preferably, the electrode layer is a metal electrode layer, and the material of the electrode layer includes any one of gold, silver and copper;

[0039] The thickness of the electrode layer is 70 to 150 nm.

[0040] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0041] depositing a first carrier transport layer on a conductive substrate;

[0042] Depositing a perovskite light absorbing layer on the first carrier transport layer by the above method;

[0043] depositing an interfacial layer on the perovskite light absorbing layer;

[0044] A second carrier transport layer, a buffer layer and an electrode layer are sequentially deposited on the interface layer.

[0045] The deposition method of the first carrier transport layer, the second carrier transport layer and the perovskite light absorption layer includes any one of coating, thermal evaporation and magnetron sputtering; the coating includes any one of spin coating, spray coating, scraping coating and slit coating.

[0046] The solvent includes an organic solvent, such as any one of ethanol, isopropanol, toluene, chlorobenzene, chloroform, ether, N,N-dimethylformamide, and dimethyl sulfoxide.

[0047] The deposition method of the electrode layer: thermal evaporation, deposition rate

[0048] The present invention achieves the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration by introducing metal pseudohalide materials during the perovskite film formation process and on the surface of the perovskite film.

[0049] In the conventional method, the perovskite film crystallization process is generally regulated by introducing additives into the perovskite precursor solution. However, for the metal pseudohalides used in the present technical solution, the metal divalent cations (such as Cd 2+ ) has a higher 2+ A smaller ionic radius forms a stronger bond with the halogen ions, which can better bind the halogen ions and slow down ion migration. However, during the nucleation process, a lower ionic radius will increase the nucleation rate, causing the perovskite grain size to decrease, which is not conducive to the formation of high-quality perovskite films.

[0050] In the present technical solution, the metal pseudohalide is introduced during the perovskite coating process. This introduction method will not affect the nucleation process of the perovskite grains, but will only affect the subsequent crystallization growth process of the perovskite grains. 2+ ) and pseudohalide anions (such as SCN - ) will be with [PbX6] 4-The regular octahedral structures interact with each other, thereby slowing down the crystal growth rate of perovskite grains. This ultimately forms a slow crystal growth process, which is beneficial to increasing the perovskite grain size and enhancing the crystallinity of the perovskite film.

[0051] The metal ion part of the metal pseudohalide, such as Cd 2+ ions, whose ionic radius is smaller than that of Pb in perovskite materials 2+ Ions can interact more strongly with halogen ions, and can interact with perovskite materials during the crystallization process to form intermediates, slowing down the crystallization process of perovskite materials and increasing the size of perovskite grains. Secondly, it can anchor halogen ions and inhibit the migration of halogen ions. At the same time, its valence is similar to that of Pb 2+ The ions are the same and can fill the Pb generated during the crystallization and annealing of the perovskite material. 2+ Vacancies reduce the defect density of the film.

[0052] The pseudohalide anion part of metal pseudohalides, such as SCN - ions, whose valence and ionic radius are similar to those of halogen anions (Br - ,I - ) is similar to that of the halogen anion vacancies generated by the perovskite during the crystallization and annealing process. - After filling the halogen vacancies and occupying the PbX6 octahedral sites in the perovskite material, the migration energy of the surrounding halogen anions increases, thereby suppressing the halogen migration phenomenon during device operation.

[0053] The above advantages work synergistically to improve the crystallinity of perovskite films, reduce the defect state density of perovskite films, inhibit halogen migration, and ultimately improve the efficiency and stability of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 is a schematic structural diagram of a perovskite solar cell in Example 2 of the present invention;

[0055] Figure 2 is an electron microscope photograph of the perovskite film in the comparative example;

[0056] Figure 3 This is an electron microscope photo of the perovskite film in Example 2;

[0057] Figure 4 is the X-ray diffraction pattern of the perovskite film in the comparative example;

[0058] Figure 5 is the X-ray diffraction pattern of the perovskite film in Example 2;

[0059] Figure 6This is a comparison chart of the stability of the perovskite solar cells in the comparative example and Example 2. DETAILED DESCRIPTION

[0060] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0061] Example 1

[0062] This embodiment provides a method for preparing a perovskite film, comprising the following steps:

[0063] The perovskite precursor deposition liquid is deposited on the first carrier transport layer, and a preset amount of a metal pseudohalide first solution is introduced during the perovskite film deposition process to be co-deposited with the perovskite film. After the deposition is completed, a first annealing is performed to obtain a perovskite light absorbing layer.

[0064] The present invention also provides a perovskite film, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the above method.

[0065] The present invention also provides a perovskite solar cell, comprising a conductive substrate, a first carrier transport layer, a perovskite light absorption layer, an interface layer, a second carrier transport layer, a buffer layer, and an electrode layer arranged in sequence, wherein the perovskite light absorption layer is the perovskite light absorption layer obtained by the above-mentioned preparation method.

[0066] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0067] depositing a first carrier transport layer on a conductive substrate;

[0068] Depositing a perovskite light absorbing layer on the first carrier transport layer by the above method;

[0069] Depositing an interface layer on the perovskite light absorbing layer by the above method;

[0070] A second carrier transport layer, a buffer layer and an electrode layer are sequentially deposited on the interface layer.

[0071] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0072] Example 2

[0073] This embodiment provides a method for preparing a perovskite film, comprising the following steps:

[0074] The perovskite precursor deposition liquid is deposited on the first carrier transport layer, and a preset amount of a metal pseudohalide first solution is introduced during the perovskite film deposition process to be co-deposited with the perovskite film. After the deposition is completed, a first annealing is performed to obtain a perovskite light absorbing layer.

[0075] Preferably, the metal pseudohalide in the first metal pseudohalide solution has a general structural formula of RY2, wherein R is an ionic radius smaller than that of Pb 2+ divalent metal cations and capable of forming chemical bonds with the perovskite X-site halogen anions, wherein R comprises a cadmium ion (Cd 2+ ), strontium ion (Sr 2+ ), palladium ions (Pd 2+ ), cobalt ions (Co 2+ ), zinc ion (Zn 2+ ), copper ions (Cu 2+ ), nickel ions (Ni 2+ ) any one or more of;

[0076] Y is a pseudohalide anion, Y includes thiocyanate (SCN - ), cyanide (CN - ), cyanate (OCN - ), hypothiocyanate (OSCN - ), selenocyanate (SeCN - ), azide (N3 - ), nitrite (NO2 - ), formate (HCOO - ), acetate (CH3COO - ), propionate (CH3CH2COO - ), butyrate (CH3(CH2)2COO - ), valerate (CH3(CH2)3COO - ), hexanoate (CH3(CH2)4COO - ) any one or more of them.

[0077] Preferably, the concentration of the first metal pseudo-halide solution is 0.3-0.8 mg / mL, the solvent in the first metal pseudo-halide solution is chlorobenzene and isopropanol, and the volume ratio of chlorobenzene to isopropanol is (8-10):1.

[0078] Preferably, the first annealing is annealing at 55-65° C. for 1-5 min, and then annealing at 100-140° C. for 5-18 min.

[0079] Preferably, the thickness of the perovskite light absorbing layer is 300-800 nm.

[0080] Specifically, the thickness of the perovskite light absorbing layer in this embodiment is 500 nm.

[0081] Preferably, the method for preparing the perovskite film further comprises the following steps:

[0082] The second metal pseudo-halide solution is deposited on the perovskite light absorbing layer, and a second annealing is performed to obtain an interface layer.

[0083] The perovskite film further includes an interface layer disposed on the perovskite light absorbing layer.

[0084] Preferably, the concentration of the second metal pseudo-halide solution is 0.1-3 mg / mL, and the solvent in the second metal pseudo-halide solution is any one of ethanol, isopropanol, toluene, chlorobenzene, chloroform, and ether.

[0085] The metal pseudohalide in the second solution of metal pseudohalide has a general structural formula of RY2, wherein R is an ionic radius smaller than that of Pb 2+ divalent metal cations and capable of forming chemical bonds with the perovskite X-site halogen anions, wherein R comprises a cadmium ion (Cd 2+ ), strontium ion (Sr 2+ ), palladium ions (Pd 2+ ), cobalt ions (Co 2+ ), zinc ion (Zn 2+ ), copper ions (Cu 2+ ), nickel ions (Ni 2+ ) any one or more of;

[0086] Y is a pseudohalide anion, Y includes thiocyanate (SCN - ), cyanide (CN - ), cyanate (OCN - ), hypothiocyanate (OSCN - ), selenocyanate (SeCN - ), azide (N3 - ), nitrite (NO2 - ), formate (HCOO - ), acetate (CH3COO - ), propionate (CH3CH2COO - ), butyrate (CH3(CH2)2COO - ), valerate (CH3(CH2)3COO - ), hexanoate (CH3(CH2)4COO - ) any one or more of them.

[0087] Preferably, the second annealing temperature is 60-100° C. and the time is 3-15 min.

[0088] Preferably, the thickness of the interface layer is 1-20 nm. The interface layer is composed of metal pseudo-halide.

[0089] Specifically, the thickness of the interface layer in this embodiment is 10 nm.

[0090] In the technical solution, the metal pseudohalide is introduced during the perovskite coating process. The introduction of the metal pseudohalide during the coating process effectively avoids the nucleation process of the perovskite crystal in the initial coating of the perovskite film. For example, during the spin coating process, part of the solution system has reached an oversaturated state to produce nucleation, and the application of solvents such as chlorobenzene will accelerate this oversaturation process. The introduction of the metal pseudohalide in this step can avoid its influence on the nucleation process and affect the subsequent crystal growth process. Among them, the divalent metal cation (such as Cd 2+ ) and pseudohalide anions (such as SCN - ) will be with [PbX6] 4- The regular octahedral structures interact with each other, thereby slowing down the crystal growth rate of perovskite grains. This ultimately forms a slow crystal growth process, which is beneficial to increasing the perovskite grain size and enhancing the crystallinity of the perovskite film.

[0091] The present invention also provides a perovskite film, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the above method.

[0092] The material of the perovskite light-absorbing layer is an ABX3 perovskite light-absorbing material doped with a metal pseudohalide, wherein A includes CH3NH3 + 、CH(NH2)2 + 、(CH3)2NH2 + , Cs + One or more of; B includes Pb 2+ and / or Sn 2+ ; X is a halogen ion I - Br - , Cl - One or more of. Among them, CH3NH3 + (methylamine ion, MA + )、(CH3)2NH2 + (dimethylammonium ion, DMA + )、CH(NH2)2 + (Formamidinium ion, FA + ).

[0093] like Figure 1As shown, the present invention also provides a perovskite solar cell, comprising a conductive substrate, a first carrier transport layer, a perovskite light absorption layer, an interface layer, a second carrier transport layer, a buffer layer, and an electrode layer arranged in sequence, wherein the perovskite light absorption layer is the perovskite light absorption layer obtained by the above preparation method. Specifically, the perovskite solar cell is provided with the above layers in sequence from top to bottom.

[0094] Preferably, the conductive substrate includes any one of ITO, FTO and AZO.

[0095] Preferably, the first carrier transport layer is a first hole transport layer, and the second carrier transport layer is a first electron transport layer;

[0096] The first carrier transport layer is a second electron transport layer, and the second carrier transport layer is a second hole transport layer.

[0097] Preferably, the material of the first hole transport layer or the second hole transport layer is [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid (4PADCB), [2-(9H-carbazole-9-yl)ethyl]phosphoric acid (2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid (Me-4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid ( MeO-2PACz), 2,2',7,7'-tetrakis[N,N-di(4-methylphenyl)amino]-9,9'-spirobifluorene (Spiro-TTB), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), poly(3-hexylthiophene-2,5-diyl) (P3HT), poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD), nickel oxide (NiO x ), cuprous thiocyanate (CuSCN), copper iodide (CuI).

[0098] Preferably, the material of the first electron transport layer or the second electron transport layer includes C 60 ,[6,6]-phenyl-C 61 - any one of methyl butyrate (PCBM), tin oxide (SnO2), zinc oxide (ZnO), and titanium oxide (TiO2).

[0099] Preferably, the thickness of the first carrier transport layer is 1 to 100 nm, and the thickness of the second carrier transport layer is 1 to 100 nm.

[0100] Specifically, in this embodiment, the thickness of the first carrier transport layer is 2 nm.

[0101] Preferably, the material of the buffer layer is SnO2 or 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP);

[0102] The thickness of the buffer layer is 2 to 10 nm.

[0103] Preferably, the electrode layer is a metal electrode layer, and the material of the electrode layer includes any one of gold, silver and copper;

[0104] The thickness of the electrode layer is 70 to 150 nm.

[0105] The present invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0106] depositing a first carrier transport layer on a conductive substrate;

[0107] Depositing a perovskite light absorbing layer on the first carrier transport layer by the above method;

[0108] Depositing an interface layer on the perovskite light absorbing layer by the above method;

[0109] A second carrier transport layer, a buffer layer and an electrode layer are sequentially deposited on the interface layer.

[0110] The deposition method of the first carrier transport layer, the second carrier transport layer and the perovskite light absorption layer includes any one of coating, thermal evaporation and magnetron sputtering; the coating includes any one of spin coating, spray coating, scraping coating and slit coating.

[0111] The solvent includes an organic solvent, such as any one of ethanol, isopropanol, toluene, chlorobenzene, chloroform, ether, N,N-dimethylformamide, and dimethyl sulfoxide.

[0112] The deposition method of the electrode layer: thermal evaporation, deposition rate Specifically, the deposition rate of the electrode layer in this embodiment is

[0113] Specifically, this embodiment also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0114] (1) Treating the conductive substrate: Using ITO conductive glass as the substrate, ultrasonically treating with glass cleaning agent, deionized water, ethanol, acetone, isopropanol and ethanol for 10 min in sequence, then drying the substrate with dry air, and then treating with UV-ozone for 15 min;

[0115] (2) Preparation of the first carrier transport layer (hole transport layer): Spin coating a 0.4 mg / mL ethanol solution of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid on the pre-cleaned ITO conductive glass at a spin coating speed of 4000 rpm for 10 s, and then annealing at 100° C. for 10 min to obtain a hole transport layer;

[0116] (3) Preparation of perovskite precursor solution: PbI2 (lead iodide), FAI (formamidinium iodide), PbBr2 (lead bromide), and FABr (formamidinium bromide) were dissolved in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a molar ratio of 0.75:0.75:0.25:0.25 to form a perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 4:1. 2+ The concentration is 1.5mol / L.

[0117] (4) Preparing a solution containing a metal pseudohalide: adding Cd(SCN)2 in an amount of 0.5 mg / mL to a mixed solution of chlorobenzene and isopropanol, wherein the volume ratio of chlorobenzene to isopropanol is 9:1, to obtain the solution.

[0118] (5) Preparing a perovskite light-absorbing layer: spin-coating the perovskite precursor solution on the hole transport layer (2) in steps, wherein the first step spin-coating rate is 1000 rpm for 10 s, and the second step spin-coating rate is 3000 rpm for 20 s. Meanwhile, after rotating at 1000 rpm for 10 s, the solution of step (4) is added dropwise. After the spin-coating is completed, annealing is performed, wherein the first step annealing temperature is 60° C. for 2 min, and the second step annealing temperature is 120° C. for 15 min, to obtain the perovskite light-absorbing layer.

[0119] (6) preparing an interface layer: mixing Cd(SCN)2 and isopropanol to obtain a solution with a concentration of 0.5 mg / mL, and then spin coating the solution on the perovskite light absorbing layer at a speed of 6000 rpm for 30 seconds, followed by annealing at 100°C for 10 minutes to obtain the interface layer;

[0120] (7) Preparation of the second carrier transport layer (electron transport layer): Using the evaporation method, C 60 Evaporation is carried out on the interface layer at a rate of The thickness of C is 30nm. 60 layer;

[0121] (8) Preparing a buffer layer and an electrode layer: A 7 nm thick 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) buffer layer and a 100 nm thick silver layer are sequentially deposited on the electron transport layer by an evaporation method to obtain the perovskite solar cell.

[0122] The present invention achieves the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration by introducing metal pseudohalide materials during the perovskite film formation process and on the surface of the perovskite film.

[0123] In the conventional method, the perovskite film crystallization process is generally regulated by introducing additives into the perovskite precursor solution. However, for the metal pseudohalides used in the present technical solution, the metal divalent cations (such as Cd 2+ ) has a higher 2+ A smaller ionic radius forms a stronger bond with the halogen ions, which can better bind the halogen ions and slow down ion migration. However, during the nucleation process, a lower ionic radius will increase the nucleation rate, causing the perovskite grain size to decrease, which is not conducive to the formation of high-quality perovskite films.

[0124] In the present technical solution, the metal pseudohalide is introduced during the perovskite coating process. This introduction method will not affect the nucleation process of the perovskite grains, but will only affect the subsequent crystallization growth process of the perovskite grains. 2+ ) and pseudohalide anions (such as SCN - ) will be with [PbX6] 4- The regular octahedral structures interact with each other, thereby slowing down the crystal growth rate of perovskite grains. This ultimately forms a slow crystal growth process, which is beneficial to increasing the perovskite grain size and enhancing the crystallinity of the perovskite film.

[0125] The metal ion part of the metal pseudohalide, such as Cd 2+ ions, whose ionic radius is smaller than that of Pb in perovskite materials 2+ Ions can interact more strongly with halogen ions, and can interact with perovskite materials during the crystallization process to form intermediates, slowing down the crystallization process of perovskite materials and increasing the size of perovskite grains. Secondly, it can anchor halogen ions and inhibit the migration of halogen ions. At the same time, its valence is similar to that of Pb 2+ The ions are the same and can fill the Pb generated during the crystallization and annealing of the perovskite material. 2+ Vacancies reduce the defect density of the film.

[0126] The pseudohalide anion part of metal pseudohalides, such as SCN - ions, whose valence and ionic radius are similar to those of halogen anions (Br - ,I - ) is similar to that of the halogen anion vacancies generated by the perovskite during the crystallization and annealing process. - After filling the halogen vacancies and occupying the PbX6 octahedral sites in the perovskite material, the migration energy of the surrounding halogen anions increases, thereby suppressing the halogen migration phenomenon during device operation.

[0127] The above advantages work synergistically to improve the crystallinity of perovskite films, reduce the defect state density of perovskite films, inhibit halogen migration, and ultimately improve the efficiency and stability of perovskite solar cells.

[0128] Example 3

[0129] This embodiment provides a method for preparing a perovskite solar cell, which differs from the method for preparing the cell in Embodiment 2 in that:

[0130] The difference between Example 3 and Example 2 is that Cd(SCN)2 is not added to the solution in step (4), and the rest of the preparation methods and parameters are consistent with those of Example 2.

[0131] The present embodiment achieves the purpose of introducing metal pseudo-halide materials on the surface of the perovskite film, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, passivating surface defect sites of the perovskite film, and inhibiting halogen ion migration.

[0132] Example 4

[0133] This embodiment provides a method for preparing a perovskite solar cell, which differs from the method for preparing the cell in Embodiment 2 in that:

[0134] The difference between Example 4 and Example 2 is that step (6) is not performed to prepare the interface layer, and the rest of the preparation methods and parameters are consistent with Example 2.

[0135] This embodiment introduces metal pseudohalide materials during the perovskite film formation process to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0136] Example 5

[0137] This embodiment provides a method for preparing a perovskite solar cell, which differs from the method for preparing the cell in Embodiment 2 in that:

[0138] The difference between Example 5 and Example 2 is that the metal pseudohalide used is cadmium formate Cd(HCOO)2, and the rest of the preparation method and parameters are consistent with Example 2.

[0139] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0140] Example 6

[0141] This embodiment provides a method for preparing a perovskite solar cell, which differs from the method for preparing the cell in Embodiment 2 in that:

[0142] The difference between Example 6 and Example 2 is that the metal pseudohalide used is cadmium acetate Cd(CH3COO)2, and the rest of the preparation method and parameters are consistent with Example 2.

[0143] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0144] Example 7

[0145] This embodiment provides a method for preparing a perovskite solar cell, which differs from the method for preparing the cell in Embodiment 2 in that:

[0146] The difference between Example 7 and Example 2 is that Cd(SCN)2 is directly added into the perovskite precursor solution in step (3), and Cd(SCN)2 is not added to the solution in step (4). The rest of the preparation method and parameters are consistent with Example 2.

[0147] This embodiment introduces metal pseudohalide materials on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0148] Comparative Example

[0149] The difference between the comparative example and Example 2 is that Cd(SCN)2 is not added to the solution in step (4), and step (6) of preparing the interface layer is not performed. The remaining preparation methods and parameters are the same as those in Example 2.

[0150] Performance Testing

[0151] The batteries prepared in the examples and comparative examples were subjected to current-voltage characteristic (JV) tests, using AM1.5G light source, 100 mW cm -2 Sunlight simulates the light source. The open circuit voltage of the battery (V OC ), short-circuit current density (J SC ), fill factor (FF) and power conversion efficiency (PCE), among which the open circuit voltage (V OC ), short-circuit current density (J SC ), fill factor (FF) is obtained from the tested JV characteristic curve, power conversion efficiency (PCE) = (V OC×J SC ×FF) / 100mW cm -2 The test results are recorded in Table 1.

[0152] From the information in Table 1, it can be seen that Example 2 has the highest conversion efficiency, indicating that the introduction of metal pseudo-halide materials in the deposition process of the perovskite film in this technical solution can regulate the crystallization process of the perovskite film and improve the crystallization quality of the perovskite film. At the same time, the deposition of metal pseudo-halide materials on the surface of the perovskite film can passivate the metal and halogen defects on the surface of the perovskite film, block the halogen migration path, and inhibit the migration of halogen ions. The two strategies work together to improve the stability and conversion efficiency of perovskite solar cells.

[0153] The test results of Example 3 and Example 4 show that the introduction of metal pseudo-halides during the deposition process of the perovskite film and on the surface of the perovskite film can have a beneficial effect on improving the conversion efficiency of the device.

[0154] Examples 5 and 6 show that using different pseudohalogen anions can have beneficial effects, indicating the universality of the present technical solution.

[0155] Example 7 shows that directly introducing metal pseudohalides into the perovskite precursor solution can have a beneficial effect on the efficiency of perovskite solar cells, but its beneficial effect is lower than that of the present technical solution. This shows that the present technical solution adopts the strategy of introducing metal pseudohalides during the deposition process of the perovskite film to specifically regulate the perovskite crystallization process and improve the crystallinity of the perovskite film.

[0156] Examples 8-18 show that the present technical solution is applicable to different perovskite solar cell structures, different transport layer materials and different perovskite material systems, indicating that the present technical solution has universal applicability.

[0157] like Figure 2 This is an electron microscope photo of the perovskite film in the comparative example. Figure 3 This is an electron microscope photo of the perovskite film in Example 2. The scanning electron microscope model is JEOL-6701F, and the magnification is 30,000 times. By comparison, it can be found that Figure 3 Compared with the perovskite film Figure 2 The perovskite films in the experiment showed larger grain sizes, which indicated that the introduction of metal pseudohalides during the deposition process of perovskite films could delay the crystallization of perovskite, promote the grain growth of perovskite films, and increase the grain size of perovskite films.

[0158] Figure 4 is the X-ray diffraction spectrum of the perovskite film in the comparative example, Figure 5The X-ray diffraction pattern of the perovskite film in Example 2 is shown in Figure 2. The model of the X-ray diffractometer is Rigaku, D / max 2500VB25 / PC. By comparison, it is found that the XRD diffraction peak intensity of the perovskite film in Example 2 is significantly stronger than that of the perovskite film in the comparative example, indicating that the perovskite film in Example 2 has better crystallinity. The enhancement of its crystallinity is due to the fact that the introduced metal pseudohalide can regulate the crystallization process of the perovskite film, slow down the crystallization speed of the perovskite, and promote the full crystallization of the perovskite.

[0159] The batteries prepared in the comparative example and Example 2 were placed in the air, and their JV characteristic curves were periodically measured to obtain the power conversion efficiency (PCE) of the batteries. The PCE data were normalized to obtain Figure 6 The purpose of normalization is to facilitate the comparison of PCE data at the same starting point. By comparison, it can be found that the battery sample of Example 2 shows longer stability than that of the comparative example, which indicates that the metal pseudohalide introduced in Example 2 plays a role in filling the vacancies between metal and halogen ions and blocking the migration path of halogen ions, thereby improving the stability of the solar cell device.

[0160] Table 1 Battery performance table

[0161] Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF(%) PCE(%) Example 2 1.183 20.31 81.95 19.69 Example 3 1.173 19.68 77.84 17.97 Example 4 1.177 19.91 78.20 18.32 Example 5 1.191 19.05 79.82 18.11 Example 6 1.188 20.40 79.55 19.28 Example 7 1.159 20.28 80.19 18.85 Example 8 1.179 19.52 79.90 18.39 Example 9 1.172 20.33 78.96 18.81 Example 10 0.739 26.32 76.43 14.87 Embodiment 11 1.168 20.46 78.63 18.79 Example 12 1.172 19.77 79.23 18.36 Embodiment 13 1.164 19.82 78.45 18.10 Embodiment 14 1.183 19.91 78.34 18.45 Embodiment 15 1.190 19.46 78.51 18.18 Example 16 1.186 19.43 79.12 18.23 Embodiment 17 1.175 20.04 78.95 18.59 Embodiment 18 1.185 20.13 79.26 18.91 Comparative Example 1.142 19.26 69.97 15.389

[0162] Example 8

[0163] This embodiment provides a method for preparing a perovskite film, comprising the following steps:

[0164] (1) Preparation of perovskite precursor solution: PbI2 (lead iodide), FAI (formamidinium iodide), PbBr2 (lead bromide), and FABr (formamidinium bromide) were dissolved in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a molar ratio of 0.75:0.75:0.25:0.25 to form a perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 4:1. 2+ The concentration is 1.5mol / L.

[0165] (2) Preparing a solution containing a metal pseudohalide: Sr(CN)2 was added in an amount of 0.3 mg / mL to a mixed solution of chlorobenzene and isopropanol, wherein the volume ratio of chlorobenzene to isopropanol was 10:1, to obtain the solution.

[0166] (3) depositing a perovskite precursor deposition liquid on the first carrier transport layer, and introducing a preset amount of a first metal pseudohalide solution during the perovskite film deposition process to co-deposit the perovskite film;

[0167] After the deposition is completed, annealing is performed at 65°C for 1 minute and then at 100°C for 12 minutes to obtain a perovskite light absorbing layer. The perovskite film includes a perovskite light absorbing layer. The thickness of the perovskite light absorbing layer is 300 nm.

[0168] (4) Sr(CN)2 and isopropanol were mixed to obtain a solution with a concentration of 0.8 mg / mL, and then spin-coated on the perovskite light absorbing layer at a speed of 6000 rpm for 30 seconds, followed by annealing at 80°C for 3 minutes to obtain the interface layer. The perovskite film also includes an interface layer disposed on the perovskite light absorbing layer. The thickness of the interface layer is 20 nm.

[0169] The present invention also provides a perovskite film, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the above method.

[0170] The present invention also provides a perovskite solar cell, comprising a conductive substrate, a first carrier transport layer, a perovskite light absorption layer, an interface layer, a second carrier transport layer, a buffer layer, and an electrode layer arranged in sequence, wherein the perovskite light absorption layer is the perovskite light absorption layer obtained by the above-mentioned preparation method.

[0171] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0172] (1) Treating the conductive substrate: FTO conductive glass was used as the substrate, and glass cleaning agent, deionized water, ethanol, acetone, isopropanol and ethanol were ultrasonicated for 10 min in sequence, and then the substrate was blown dry with dry air, followed by UV-ozone treatment for 15 min;

[0173] (2) Preparation of the first carrier transport layer (hole transport layer): Spin coat a 0.4 mg / mL ethanol solution of [2-(9H-carbazole-9-yl)ethyl]phosphoric acid (2PACz) on the pre-cleaned FTO conductive glass at a spin coating speed of 4000 rpm for 10 s, and then anneal at 100°C for 10 min to obtain a hole transport layer; the thickness of the first carrier transport layer is 2 nm.

[0174] (3) Preparation of perovskite precursor solution: PbI2 (lead iodide), FAI (formamidinium iodide), PbBr2 (lead bromide), and FABr (formamidinium bromide) were dissolved in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a molar ratio of 0.75:0.75:0.25:0.25 to form a perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 4:1. 2+ The concentration is 1.5mol / L.

[0175] (4) Preparing a solution containing a metal pseudohalide: Sr(CN)2 was added in an amount of 0.3 mg / mL to a mixed solution of chlorobenzene and isopropanol, wherein the volume ratio of chlorobenzene to isopropanol was 10:1, to obtain the solution.

[0176] (5) Preparing a perovskite light-absorbing layer: spin-coating the perovskite precursor solution on the hole transport layer (2) in steps, wherein the first step spin-coating rate is 1000 rpm for 10 s, and the second step spin-coating rate is 3000 rpm for 20 s. Meanwhile, after rotating at 1000 rpm for 10 s, the solution of step (4) is added dropwise. After the spin-coating is completed, annealing is performed, wherein the first step annealing temperature is 65° C. for 1 min, and the second step annealing temperature is 100° C. for 12 min, to obtain the perovskite light-absorbing layer.

[0177] (6) preparing an interface layer: Sr(CN)2 and ethanol were mixed to obtain a solution with a concentration of 0.1 mg / mL, and then spin-coated on the perovskite light absorbing layer at a speed of 6000 rpm for 30 seconds, followed by annealing at 80°C for 3 minutes to obtain the interface layer;

[0178] (7) Preparation of the second carrier transport layer (electron transport layer): [6,6]-phenyl-C 61 -Methyl butyrate (PCBM) is evaporated on the interface layer at a rate of A PCBM layer with a thickness of 50 nm is obtained;

[0179] (8) Preparation of buffer layer and electrode layer: A 2 nm thick SnO2 buffer layer was deposited on the electron transport layer by atomic layer deposition, and a 70 nm thick gold layer was deposited on the buffer layer by thermal evaporation. The thermal evaporation deposition rate was The perovskite solar cell is obtained.

[0180] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0181] Example 9

[0182] This embodiment provides a method for preparing a perovskite film, comprising the following steps:

[0183] (1) Preparation of perovskite precursor solution: PbI2 (lead iodide), FAI (formamidinium iodide), PbBr2 (lead bromide), and FABr (formamidinium bromide) were dissolved in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a molar ratio of 0.75:0.75:0.25:0.25 to form a perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 4:1. 2+ The concentration is 1.5mol / L.

[0184] (2) Preparing a solution containing a metal pseudohalide: Pd(OCN)2 was added to a mixed solution of chlorobenzene and isopropanol in an amount of 0.8 mg / mL, wherein the volume ratio of chlorobenzene to isopropanol was 8:1, to obtain the solution.

[0185] (3) depositing a portion of the perovskite precursor solution on the first carrier transport layer to obtain a first deposition layer;

[0186] Dropping a preset amount of a first metal pseudo-halide solution on the first deposition layer;

[0187] The remaining perovskite precursor solution is continuously deposited to obtain a second deposition layer;

[0188] The film is first annealed at 55°C for 5 minutes and then annealed at 140°C for 18 minutes to obtain a perovskite light absorbing layer. The perovskite film includes a perovskite light absorbing layer. The thickness of the perovskite light absorbing layer is 800 nm.

[0189] (4) Pd(OCN)2 and isopropanol were mixed to obtain a solution with a concentration of 0.3 mg / mL, and then spin-coated on the perovskite light absorbing layer at a speed of 6000 rpm for 30 seconds, followed by annealing at 60°C for 15 minutes to obtain the interface layer. The perovskite film also includes an interface layer disposed on the perovskite light absorbing layer. The thickness of the interface layer is 1 nm.

[0190] The present invention also provides a perovskite film, comprising a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the above method.

[0191] The present invention also provides a perovskite solar cell, comprising a conductive substrate, a first carrier transport layer, a perovskite light absorption layer, an interface layer, a second carrier transport layer, a buffer layer, and an electrode layer arranged in sequence, wherein the perovskite light absorption layer is the perovskite light absorption layer obtained by the above-mentioned preparation method.

[0192] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0193] (1) Treating the conductive substrate: AZO conductive glass was used as the substrate, and glass cleaning agent, deionized water, ethanol, acetone, isopropanol and ethanol were ultrasonicated for 10 min in sequence, and then the substrate was blown dry with dry air, followed by UV-ozone treatment for 15 min;

[0194] (2) Preparation of the first carrier transport layer (hole transport layer): Spin coat a 0.4 mg / mL ethanol solution of [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid (Me-4PACz) on the pre-cleaned AZO conductive glass at a spin coating speed of 4000 rpm for 10 s, and then anneal at 100°C for 10 min to obtain a hole transport layer; the thickness of the first carrier transport layer is 2 nm.

[0195] (3) Preparation of perovskite precursor solution: PbI2 (lead iodide), FAI (formamidinium iodide), PbBr2 (lead bromide), and FABr (formamidinium bromide) were dissolved in a mixed solution of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) at a molar ratio of 0.75:0.75:0.25:0.25 to form a perovskite precursor solution, wherein the volume ratio of DMF to DMSO was 4:1. 2+ The concentration is 1.5mol / L.

[0196] (4) Preparing a solution containing a metal pseudohalide: Pd(OCN)2 was added to a mixed solution of chlorobenzene and isopropanol in an amount of 0.8 mg / mL, wherein the volume ratio of chlorobenzene to isopropanol was 8:1, to obtain the solution.

[0197] (5) Preparing a perovskite light-absorbing layer: spin-coating the perovskite precursor solution on the hole transport layer (2) in steps, wherein the first step spin-coating rate is 1000 rpm for 10 s, and the second step spin-coating rate is 3000 rpm for 20 s. Meanwhile, after rotating at 1000 rpm for 10 s, the solution of step (4) is added dropwise. After the spin-coating is completed, annealing is performed, wherein the first step annealing temperature is 55° C. for 5 min, and the second step annealing temperature is 140° C. for 18 min, to obtain the perovskite light-absorbing layer.

[0198] (6) preparing an interface layer: mixing Pd(OCN)2 and toluene to obtain a solution with a concentration of 3 mg / mL, and then spin coating the solution on the perovskite light absorbing layer at a speed of 6000 rpm for 30 seconds, followed by annealing at 60°C for 15 minutes to obtain the interface layer;

[0199] (7) Preparation of the second carrier transport layer (electron transport layer): Using the evaporation method, C 60 Evaporation is carried out on the interface layer at a rate of The thickness of C is 20 nm. 60 layer;

[0200] (8) Preparation of buffer layer and electrode layer: A 5 nm thick 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) buffer layer was deposited on the electron transport layer by evaporation, and a 150 nm thick copper layer was deposited on the buffer layer by thermal evaporation. The thermal evaporation deposition rate was 2.50 %. The perovskite solar cell is obtained.

[0201] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0202] Example 10

[0203] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0204] The metal pseudohalide used in the preparation is Co(OSCN)2.

[0205] The material of the prepared perovskite light-absorbing layer is ABX3 perovskite light-absorbing material doped with metal pseudohalide, and ABX3 is MAPb 0.5 Sn 0.5 I3.

[0206] This embodiment provides a perovskite film, which is prepared by the above method.

[0207] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0208] The material of the first carrier transport layer is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid (MeO-2PACz).

[0209] The material of the second carrier transport layer is ZnO.

[0210] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0211] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0212] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0213] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0214] Embodiment 11

[0215] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0216] The metal pseudohalide used in the preparation is Zn(CH3CH2COO - )2.

[0217] The material of the prepared perovskite light-absorbing layer is ABX3 perovskite light-absorbing material doped with metal pseudohalide, and ABX3 is DMA 0.1 Cs 0.25 FA 0.6 MA 0.05 PbI 2.7 Br 0.3 .

[0218] This embodiment provides a perovskite film, which is prepared by the above method.

[0219] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0220] The material of the first carrier transport layer is SnO2.

[0221] The material of the second carrier transport layer is 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD).

[0222] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0223] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0224] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0225] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0226] Example 12

[0227] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0228] The metal pseudohalide used in the preparation is Cu(N3)2.

[0229] The material of the prepared perovskite light-absorbing layer is ABX3 perovskite light-absorbing material doped with metal pseudohalide, where ABX3 is Cs 0.22 FA 0.78 Pb(I 0.85 Br 0.15 )3-CsPbCl3.

[0230] This embodiment provides a perovskite film, which is prepared by the above method.

[0231] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0232] The material of the first carrier transport layer is poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA).

[0233] The material of the second carrier transport layer is C 60 .

[0234] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0235] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0236] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0237] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0238] Embodiment 13

[0239] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0240] The metal pseudohalide used in the preparation is Ni(NO2)2.

[0241] This embodiment provides a perovskite film, which is prepared by the above method.

[0242] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0243] The material of the first carrier transport layer is poly(3-hexylthiophene-2,5-diyl) (P3HT).

[0244] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0245] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0246] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0247] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0248] Embodiment 14

[0249] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0250] The metal pseudohalide used in the preparation is Sr(CH3COO)2.

[0251] This embodiment provides a perovskite film, which is prepared by the above method.

[0252] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0253] The material of the first carrier transport layer is poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD).

[0254] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0255] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0256] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0257] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0258] Embodiment 15

[0259] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0260] The metal pseudohalide used in the preparation is Co(CH3CH2COO)2.

[0261] This embodiment provides a perovskite film, which is prepared by the above method.

[0262] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0263] The material of the first carrier transport layer is NiO x .

[0264] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0265] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0266] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0267] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0268] Example 16

[0269] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0270] The metal pseudohalide used in the preparation is Zn[CH3(CH2)2COO]2.

[0271] This embodiment provides a perovskite film, which is prepared by the above method.

[0272] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0273] The material of the first carrier transport layer is TiO2.

[0274] The material of the second carrier transport layer is cuprous thiocyanate (CuSCN).

[0275] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0276] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0277] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0278] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0279] Embodiment 17

[0280] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0281] The metal pseudohalide used in the preparation is Cu[CH3(CH2)3COO]2.

[0282] This embodiment provides a perovskite film, which is prepared by the above method.

[0283] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0284] The material of the first carrier transport layer is TiO2.

[0285] The material of the second carrier transport layer is CuI.

[0286] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0287] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0288] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0289] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0290] Embodiment 18

[0291] This embodiment provides a method for preparing a perovskite film, which differs from that in Embodiment 2 in that:

[0292] The metal pseudohalide used in the preparation is Ni[CH3(CH2)4COO]2.

[0293] This embodiment provides a perovskite film, which is prepared by the above method.

[0294] This embodiment provides a perovskite solar cell, which is different from that in Embodiment 2 in that:

[0295] The perovskite light-absorbing layer is the perovskite light-absorbing layer obtained by the above-mentioned preparation method.

[0296] This embodiment also provides a method for preparing the above-mentioned perovskite solar cell, which differs from that in Embodiment 2 in that:

[0297] The perovskite light absorbing layer and the interface layer are prepared by the above-mentioned method for preparing the perovskite film.

[0298] This embodiment introduces metal pseudohalide materials during the film formation process of the perovskite film and on the surface of the perovskite film to achieve the purpose of regulating the perovskite crystallization process, improving the crystallization quality of the perovskite film, increasing the perovskite grain size, anchoring halogen anions, filling halogen ion vacancies, filling lead vacancies, and inhibiting halogen ion migration.

[0299] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite film, characterized in that: The following steps are involved: The perovskite precursor deposition liquid is deposited on the first carrier transport layer, and a preset amount of a metal pseudohalide first solution is introduced during the perovskite film deposition process to be co-deposited with the perovskite film. After the deposition is completed, a first annealing is performed to obtain a perovskite light absorbing layer.

2. The method for preparing a perovskite thin film according to claim 1, characterized in that: The metal pseudo-halide in the first metal pseudo-halide solution has a general structural formula of RY2, wherein R includes any one or more of cadmium ions, strontium ions, palladium ions, cobalt ions, zinc ions, copper ions, and nickel ions; Y is a pseudohalide anion, and Y includes any one or more of thiocyanate, cyanide, cyanate, hypothiocyanate, selenocyanate, azide, nitrite, formate, acetate, propionate, butyrate, valerate, and hexanoate.

3. The method for preparing a perovskite thin film according to claim 1, characterized in that: The concentration of the first metal pseudohalide solution is 0.3-0.8 mg / mL, the solvent in the first metal pseudohalide solution is chlorobenzene and isopropanol, and the volume ratio of chlorobenzene to isopropanol is (8-10):

1.

4. The method for preparing a perovskite thin film according to claim 1, characterized in that: The first annealing is specifically annealing at 55-65° C. for 1-5 min, and then annealing at 100-140° C. for 5-18 min.

5. The method for preparing a perovskite thin film according to claim 1, characterized in that: The thickness of the perovskite light-absorbing layer is 300 to 800 nm.

6. The method for preparing a perovskite thin film according to any one of claims 1 to 5, characterized in that: The following steps are also included: The second metal pseudo-halide solution is deposited on the perovskite light absorbing layer, and a second annealing is performed to obtain an interface layer.

7. The method for preparing a perovskite thin film according to claim 6, characterized in that: The concentration of the second metal pseudo-halide solution is 0.1-3 mg / mL, and the solvent in the second metal pseudo-halide solution is any one of ethanol, isopropanol, toluene, chlorobenzene, chloroform, and ether.

8. The method for preparing a perovskite thin film according to claim 6, characterized in that: The second annealing temperature is 60-100° C., and the time is 3-15 minutes.

9. The method for preparing a perovskite thin film according to claim 6, characterized in that: The thickness of the interface layer is 1 to 20 nm.

10. A perovskite film, characterized in that: The invention comprises a perovskite light absorbing layer, wherein the perovskite light absorbing layer is prepared by the method according to any one of claims 1 to 9.

11. A perovskite solar cell, characterized in that: The invention comprises a conductive substrate, a first carrier transport layer, a perovskite light absorbing layer, an interface layer, a second carrier transport layer, a buffer layer and an electrode layer which are arranged in sequence, wherein the perovskite light absorbing layer is a perovskite light absorbing layer obtained by the preparation method according to any one of claims 1 to 9.

12. The perovskite solar cell according to claim 11, characterized in that: The conductive substrate includes any one of ITO, FTO and AZO.

13. The perovskite solar cell according to claim 11, characterized in that: The first carrier transport layer is a first hole transport layer, and the second carrier transport layer is a first electron transport layer; The first carrier transport layer is a second electron transport layer, and the second carrier transport layer is a second hole transport layer.

14. The perovskite solar cell according to claim 13, characterized in that: The material of the first hole transport layer or the second hole transport layer is any one of [4-(7H-dibenzocarbazole-7-yl)butyl]phosphoric acid, [2-(9H-carbazole-9-yl)ethyl]phosphoric acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphoric acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid, 2,2',7,7'-tetrakis[N,N-di(4-methylphenyl)amino]-9,9'-spirobifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), poly[bis(4-phenyl)(4-butylphenyl)amine], nickel oxide, cuprous thiocyanate, and copper iodide.

15. The perovskite solar cell according to claim 13, characterized in that: The material of the first electron transport layer or the second electron transport layer includes C 60 ,[6,6]-phenyl-C 61 - any one of methyl butyrate, tin oxide, zinc oxide and titanium oxide.

16. The perovskite solar cell according to claim 11, characterized in that: The thickness of the first carrier transport layer is 1 to 100 nm, and the thickness of the second carrier transport layer is 1 to 100 nm.

17. The perovskite solar cell according to claim 11, characterized in that: The material of the buffer layer is SnO2 or 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline; The thickness of the buffer layer is 2 to 10 nm.

18. The perovskite solar cell according to claim 11, characterized in that: The electrode layer is a metal electrode layer, and the material of the electrode layer includes any one of gold, silver and copper; The thickness of the electrode layer is 70 to 150 nm.

19. A method for preparing a perovskite solar cell according to any one of claims 11 to 18, characterized in that: The following steps are involved: depositing a first carrier transport layer on a conductive substrate; Prepare a perovskite light absorbing layer by the method according to any one of claims 1 to 5; preparing an interface layer; A second carrier transport layer, a buffer layer and an electrode layer are sequentially deposited on the interface layer.

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