Perovskite solar cell

Abstract

The invention relates to the technical field of solar cells, in particular to a perovskite solar cell. The invention provides a perovskite solar cell. The perovskite solar cell comprises a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer which are stacked in sequence, the electron transport layer is made of inorganic metal oxide nanoparticles; the electron transport layer is prepared by a solution method; an interface buffer layer is arranged between the perovskite layer and the electron transport layer, and the material of the interface buffer layer is a first organic material; and / or the material of the electron transport layer further comprises a second organic material; the first organic material and the second organic material independently comprise an organic polymer and / or an organic small molecule material. According to the perovskite solar cell, the electron transport layer can be prepared by a solution method, and the performance requirement can be met.

Description

Technical Field

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

[0002] Currently, the electron transport layer of inverted perovskite solar cells usually adopts methods such as vacuum thermal evaporation of C60, spin coating of PCBM, or atomic layer deposition of SnO2. However, vacuum evaporation and atomic layer deposition technologies are complex, require vacuum equipment, and are expensive. Moreover, during the process of atomic layer deposition of SnO2, the water molecules brought by the oxygen source invading the perovskite layer are likely to cause decomposition, and the Sn atoms brought by the tin source will disrupt the original chemical bonds of the atoms in the perovskite. In view of the above problems, if the solution method is adopted, the cost can be greatly reduced and the use of expensive vacuum equipment can be avoided. In addition, the solution method is usually carried out at a relatively low temperature, which is an important advantage especially for flexible substrates that cannot withstand high temperatures, and the operation is simple and more suitable for large-scale production. However, the material PCBM that can be prepared by the solution method currently still has problems such as high price and poor stability when exposed to air. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a perovskite solar cell. The perovskite solar cell of the present invention can realize the preparation of the electron transport layer by the solution method and can meet the performance requirements.

[0004] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0005] The present invention provides a perovskite solar cell, including a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer that are sequentially stacked;

[0006] The material of the electron transport layer is inorganic metal oxide nanoparticles;

[0007] The electron transport layer is prepared by a solution method;

[0008] An interface buffer layer is further included between the perovskite layer and the electron transport layer, and the material of the interface buffer layer is a first organic material; and / or the material of the electron transport layer further includes a second organic material;

[0009] The first organic material and the second organic material independently include organic polymers and / or organic small molecule materials;

[0010] The organic polymer includes one or more of polytriphenylamine, poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, polydimethyldiallylammonium chloride, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl);

[0011] The organic small molecule material includes an n-type organic semiconductor material; the n-type organic semiconductor material includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthraquinonyl[2,1,9-def:6,5,10-d'e'f']diisoquinoline, bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine.

[0012] Preferably, an amine compound molecule treatment layer is further provided between the perovskite layer and the interface buffer layer, or an amine compound molecule treatment layer is further provided between the perovskite layer and the electron transport layer.

[0013] Preferably, the preparation method of the amine compound molecule treatment layer includes the following steps:

[0014] Mix the amine compound molecule and a solvent to obtain a mixed solution; or mix the amine compound molecule, an organic material, and a solvent to obtain a mixed solution;

[0015] After coating the mixed solution on the surface of the perovskite layer, form a film to obtain the amine compound molecule treatment layer.

[0016] Preferably, the amine compound molecule includes one or more of methylamine iodide, methylamine chloride, methylamine bromide, formamidine iodide, formamidine chloride, formamidine bromide, 3-methylthio-1-propylamine iodide, 3-methylthio-1-propylamine chloride, 3-methylthio-1-propylamine bromide, butylamine iodide, butylamine chloride, butylamine bromide, propanediamine iodide, propanediamine chloride, propanediamine bromide, ethylenediamine iodide, ethylenediamine chloride, ethylenediamine bromide, benzylamine iodide, benzylamine chloride, benzylamine bromide, phenethylamine iodide, phenethylamine chloride, phenethylamine bromide, methoxybenzylamine iodide, methoxybenzylamine chloride, methoxybenzylamine bromide, methoxyphenethylamine iodide, methoxyphenethylamine chloride, and methoxyphenethylamine bromide;

[0017] The solvent includes one or more of isopropanol, chlorobenzene, and N,N-dimethylformamide;

[0018] The concentration of amine compound molecules in the mixed solution is 5-20 mmol / L;

[0019] The coating method is spin coating, the rotation speed of the spin coating is 800-5000 rpm, and the time is 10-120 s;

[0020] The film formation method is direct film formation or annealing film formation, the temperature of the annealing film formation is 80-150 °C, and the time is 5-10 min.

[0021] Preferably, the preparation method of the interface buffer layer includes the following steps:

[0022] Mix the first organic material with the solvent, and spin coat the obtained mixed solution to obtain the interface buffer layer.

[0023] Preferably, the concentration of the first organic material in the mixed solution is 1-5 mg / mL;

[0024] The rotation speed of the spin coating is 800-6000 rpm, and the time is 5-120 s.

[0025] Preferably, when the material of the electron transport layer further includes a second organic material, the mass ratio of the inorganic metal oxide nanoparticles to the second organic material is (5-20):(2-5).

[0026] Preferably, the preparation method of the electron transport layer includes the following steps:

[0027] Mix the inorganic metal oxide nanoparticles with the solvent to obtain a mixed solution; or mix the inorganic metal oxide nanoparticles, the second organic material, and the solvent to obtain a mixed solution;

[0028] After spin coating the mixed solution, form a film to obtain the electron transport layer.

[0029] Preferably, the solvent includes one or more of isopropanol, ethanol, methanol, chloroform, acetonitrile, and ethyl acetate;

[0030] The mass concentration of the inorganic metal oxide nanoparticles in the mixed solution is 5-20%;

[0031] The mass concentration of the second organic material in the mixed solution is 2-5%.

[0032] Preferably, the rotation speed of the spin coating is 4000-6000 rpm, and the time is 30 s;

[0033] The film-forming method is direct film-forming or annealing film-forming. The temperature for annealing film-forming is 80-150 °C, and the time is 1-30 min.

[0034] The present invention provides a perovskite solar cell. A perovskite solar cell includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer which are sequentially stacked; the material of the electron transport layer is inorganic metal oxide nanoparticles; the electron transport layer is prepared by a solution method; an interface buffer layer is further included between the perovskite layer and the electron transport layer, and the material of the interface buffer layer is a first organic material; and / or the material of the electron transport layer further includes a second organic material; the first organic material and the second organic material independently include an organic polymer and / or an organic small molecule material; the organic polymer includes one or more of poly(triphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, poly(dimethyldiallylammonium chloride), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl); the organic small molecule material includes an n-type organic semiconductor material; the n-type organic semiconductor material includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline), bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] 1) The perovskite solar cell of the present invention can realize the preparation of the electron transport layer by a solution method, avoiding the use of complex vacuum evaporation and atomic layer deposition technologies, having lower requirements for instruments, saving more raw materials, making the cost lower, and better exerting the advantage of easy processing of perovskite materials;

[0037] 2) By selecting the first organic material in the appropriate interface buffer layer and / or incorporating a second organic material into the inorganic metal oxide nanoparticles in the electron transport layer, the present invention can fill the voids formed by the inorganic metal oxide nanoparticles, alleviate oxygen vacancy defects, and form a dense and stable protective layer on the perovskite surface. And effectively passivate the defects (such as uncoordinated ions or dangling bonds) on the perovskite surface and grain boundaries, forming a passivation layer on the upper surface of the perovskite, thereby reducing non-radiative recombination centers and increasing the carrier lifetime. It can also make the material of the electron transport layer more n-type and better match the perovskite layer;

[0038] 3) The material of the electron transport layer of the present invention is selected as inorganic metal oxide nanoparticles. Since the inorganic metal oxide nanoparticles have better conductivity, higher electron mobility, smaller device resistance, it can improve the fill factor and photoelectric conversion efficiency of the device. In addition, the inorganic metal oxide nanoparticles also have better chemical stability and thermal stability under external factors such as heat, light, air, and humidity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The J-V curves of the perovskite solar cells described in Example 1 and Comparative Example 1;

[0040] Figure 2 The J-V curves of the perovskite solar cells described in Example 2 and Comparative Example 1;

[0041] Figure 3 The J-V curves of the perovskite solar cells described in Example 3 and Comparative Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0042] The present invention provides a perovskite solar cell, which includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer stacked in sequence;

[0043] The material of the electron transport layer is inorganic metal oxide nanoparticles;

[0044] The electron transport layer is prepared by a solution method;

[0045] An interface buffer layer is further included between the perovskite layer and the electron transport layer, and the material of the interface buffer layer is the first organic material; and / or the material of the electron transport layer further includes a second organic material;

[0046] The first organic material and the second organic material independently include organic polymers and / or organic small molecule materials;

[0047] The organic polymer includes one or more of poly(triphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, poly(dimethyldiallylammonium chloride), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl);

[0048] The organic small molecule material includes an n-type organic semiconductor material; the n-type organic semiconductor material includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline), bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine.

[0049] In the present invention, the conductive substrate is preferably an ITO transparent conductive substrate. Before preparing the perovskite solar cell using the ITO transparent conductive substrate, it is preferred to clean the ITO transparent conductive substrate. In the present invention, the cleaning preferably includes ultrasonic cleaning for 10 to 20 minutes in sequence with a glass cleaner, deionized water, acetone, and isopropyl alcohol. After the cleaning is completed, the present invention also preferably includes performing UV-O3 treatment on the ITO transparent conductive substrate. The present invention has no special limitation on the process of the UV-O3 treatment, and a process well-known to those skilled in the art can be used. In the present invention, the UV-O3 treatment is to remove the organic substances remaining on the surface of the ITO transparent conductive substrate and improve the work function of the ITO transparent conductive substrate.

[0050] In the present invention, the hole transport layer is preferably a single molecular layer, and the thickness of the hole transport layer is preferably 3 nm to 10 nm, more preferably 3 nm.

[0051] In the present invention, the material of the hole transport layer is preferably a self-assembled monolayer material; the self-assembled monolayer material preferably includes one or more of [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), 2-(9H-carbazol-9-yl)ethyl)phosphonic acid (2PACz), [4-(3,6-dimethyl-9H-carbazol-9-yl)butyl]phosphoric acid (Me-4PACz), and (4-(3,11-dimethoxy-7H-dibenzo[c,g]carbazol-7-yl)butyl)phosphonic acid (MeO-4PADBC). When the self-assembled molecular material is more than two of the above specific selections, the present invention has no special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0052] In the present invention, the preparation process of the hole transport layer preferably includes the following steps:

[0053] Mix the self-assembled monolayer material and a solvent to obtain a mixed solution;

[0054] After spin-coating the mixed solution, form a film directly or by annealing to obtain the hole transport layer.

[0055] In the present invention, the solvent is preferably ethanol and / or isopropanol, more preferably ethanol. The present invention has no special limitation on the mixing process, and it can be carried out by a process well-known to those skilled in the art. In the present invention, the concentration of the self-assembled monolayer material in the mixed solution is preferably 0.3 - 0.6 mg / mL, more preferably 0.4 - 0.5 mg / mL.

[0056] In the present invention, the spin-coating process is preferably to wait for 10 - 20 s after covering the surface of the substrate with the mixed solution and then carry out spin-coating; the rotation speed of the spin-coating is preferably 3000 - 5000 rpm, more preferably 4000 rpm; the time of the spin-coating is preferably 30 - 60 s, more preferably 30 s. In the present invention, the temperature of the annealing film formation is preferably 100 - 150 °C, more preferably 110 - 140 °C, and most preferably 120 - 130 °C; the time of the annealing film formation is preferably 5 - 10 min, more preferably 6 - 8 min. After the annealing is completed, the present invention also preferably includes cooling and cleaning in sequence; the present invention has no special limitation on the cooling process, and it can be carried out by a process well-known to those skilled in the art. In the present invention, the cleaning is preferably carried out with isopropanol, and the present invention has no special limitation on the specific cleaning process, and it can be carried out by a process well-known to those skilled in the art and ensure that the molecules that have not been anchored to the substrate can be removed.

[0057] In the present invention, the thickness of the perovskite layer is preferably 600 - 1000 nm, more preferably 800 nm.

[0058] In the present invention, the preparation method of the perovskite layer preferably includes the following steps:

[0059] Mix MABr, RbI, CsI, PbBr, FAI, PbI and a solvent to obtain a mixed solution;

[0060] After spin-coating the mixed solution, directly form a film or anneal to form a film to obtain the perovskite layer.

[0061] In the present invention, the solvent preferably includes a mixed solution of DMF and DMSO with a volume ratio of 4:1.

[0062] In the present invention, the dosage ratio of MABr to the solvent is preferably 5-10 mg:1 mL, more preferably 6-8 mg:1 mL; the dosage ratio of RbI to the solvent is preferably 10-20 mg:1 mL, more preferably 13-16 mg:1 mL; the dosage ratio of CsI to the solvent is preferably 20-30 mg:1 mL, more preferably 23-26 mg:1 mL; the dosage ratio of PbBr to the solvent is preferably 30-40 mg:1 mL, more preferably 33-36 mg:1 mL; the dosage ratio of FAI to the solvent is preferably 200-300 mg:1 mL, more preferably 230-260 mg:1 mL; the dosage ratio of PbI to the solvent is preferably 700-800 mg:1 mL, more preferably 730-770 mg:1 mL.

[0063] The present invention has no special limitation on the mixing process, and the process well-known to those skilled in the art can be adopted.

[0064] In the present invention, the spin-coating process preferably first accelerates to a rotation speed of 1000 rpm at an acceleration of 1000 rpm / s and then spin-coats for 10 s; then accelerates to a rotation speed of 3000 rpm at an acceleration of 3000 rpm / s and spin-coats for 30 s. At the 30th s of the entire spin-coating, chlorobenzene is preferably dropped at a dropping rate of 150 μL / s; the dosage ratio of the mixed solution to chlorobenzene is preferably 1:0.15.

[0065] In the present invention, the annealing temperature for film formation is preferably 100-150 °C, more preferably 110-140 °C, and most preferably 120-130 °C; the annealing time for film formation is preferably 10-20 min, more preferably 13-16 min.

[0066] In the present invention, an amine compound molecule treatment layer is preferably provided between the perovskite layer and the interface buffer layer, or an amine compound molecule treatment layer is preferably provided between the perovskite layer and the electron transport layer.

[0067] In the present invention, the thickness of the amine compound molecular treatment layer is preferably 2 nm to 10 nm, more preferably 5 nm.

[0068] In the present invention, the preparation method of the amine compound molecular treatment layer preferably includes the following steps:

[0069] Mix the amine compound molecules and a solvent to obtain a mixed solution; or mix the amine compound molecules, an organic material and a solvent to obtain a mixed solution;

[0070] After coating the mixed solution on the surface of the perovskite layer, form a film to obtain the amine compound molecular treatment layer.

[0071] In the present invention, the amine compound molecules and a solvent are mixed to obtain a mixed solution; or the amine compound molecules, an organic material and a solvent are mixed to obtain a mixed solution.

[0072] In the present invention, the amine compound molecules preferably include one or more of methylamine iodide, methylamine chloride, methylamine bromide, formamidine iodide, formamidine chloride, formamidine bromide, 3-methylthio-1-propylamine iodide, 3-methylthio-1-propylamine chloride, 3-methylthio-1-propylamine bromide, butylamine iodide, butylamine chloride, butylamine bromide, propanediamine iodide, propanediamine chloride, propanediamine bromide, ethylenediamine iodide, ethylenediamine chloride, ethylenediamine bromide, benzylamine iodide, benzylamine chloride, benzylamine bromide, phenethylamine iodide, phenethylamine chloride, phenethylamine bromide, methoxybenzylamine iodide, methoxybenzylamine chloride, methoxybenzylamine bromide, methoxyphenethylamine iodide, methoxyphenethylamine chloride, and methoxyphenethylamine bromide; when there are two or more of the above specific selections for the amine compound molecules, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0073] In the present invention, the solvent preferably includes one or more of isopropyl alcohol (IPA), chlorobenzene (CB), and N,N-dimethylformamide (DMF); more preferably a mixture of IPA and DMF; the volume ratio of IPA to DMF in the mixture of IPA and DMF is preferably 20:1.

[0074] In the present invention, the organic material preferably includes an organic polymer and / or an organic small molecule material; the organic polymer preferably includes one or more of poly(triphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, poly(dimethyldiallylammonium chloride), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl). When there are two or more of the above specific selections for the organic polymer, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio. In the present invention, the organic small molecule material is preferably an n-type organic semiconductor material, and the n-type organic semiconductor material preferably includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthraquinonyl[2,1,9-def:6,5,10-d'e'f']diisoquinoline, bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine; when there are two or more of the above specific selections for the organic small molecule material, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0075] In the present invention, when the mixed solution is a mixture of amine compound molecules and a solvent, the concentration of the amine compound molecules in the mixed solution is preferably 5 to 20 mmol / L, more preferably 10 to 20 mmol / L. In the examples of the present invention, the concentration of the amine compound molecules in the mixed solution can be 20 mmol / L.

[0076] When the mixed solution is a mixture of amine compound molecules, an organic material, and a solvent, the concentration of the amine compound molecules in the mixed solution is preferably 5 to 20 mmol / L, more preferably 10 to 15 mmol / L; the concentration of the organic material in the mixed solution is preferably 1 to 10 mg / L, more preferably 1 to 5 mg / L. In the examples of the present invention, the concentration of the amine compound molecules in the mixed solution can be 20 mmol / L, and the concentration of the organic material in the mixed solution can be 1 mg / L.

[0077] The present invention does not have any special limitation on the mixing process, and it can be carried out by using a process well-known to those skilled in the art.

[0078] After obtaining the mixed solution, in the present invention, the mixed solution is coated on the surface of the perovskite layer and then film-forming is carried out to obtain the amine compound molecule treatment layer.

[0079] In the present invention, the coating method is preferably spin coating; the rotation speed of the spin coating is preferably 800 - 5000 rpm, more preferably 4000 rpm; the time of the spin coating is preferably 10 - 120 s, more preferably 30 s.

[0080] In the present invention, the film-forming method is preferably direct film-forming or annealing film-forming. The temperature of the annealing film-forming is preferably 80 - 150 °C, more preferably 100 °C; the time is preferably 5 - 10 min, more preferably 7 - 8 min.

[0081] In the present invention, the function of the amine compound molecule treatment layer is to effectively passivate the defects (such as uncoordinated ions or dangling bonds) on the surface and grain boundaries of the perovskite, thereby reducing non-radiative recombination centers, increasing the carrier lifetime, and forming a stable protective layer on the perovskite surface.

[0082] In the present invention, the thickness of the interface buffer layer is preferably 3 - 10 nm, more preferably 5 nm.

[0083] In the present invention, the material of the interface buffer layer is a first organic material, and the first organic material preferably includes an organic polymer and / or an organic small molecule material; the organic polymer preferably includes one or more of poly(triphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, poly(dimethyldiallylammonium chloride), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl). When the organic polymer is two or more of the above specific selections, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio. In the present invention, the organic small molecule material is preferably an n-type organic semiconductor material, and the n-type organic semiconductor material preferably includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthraquinonyl[2,1,9-def:6,5,10-d'e'f']diisoquinoline, bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine; when the organic small molecule material is two or more of the above specific selections, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0084] In the present invention, the preparation method of the interface buffer layer includes the following steps:

[0085] Mix the first organic material and a solvent, and spin-coat the obtained mixed solution to obtain the interface buffer layer.

[0086] In the present invention, the solvent is preferably one or more of ethanol, methanol, isopropanol, and chlorobenzene; when the solvent is two or more of the above specific selections, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio. In the examples of the present invention, the solvent can be ethanol.

[0087] The present invention does not have any special limitation on the mixing process, and a process well-known to those skilled in the art can be adopted.

[0088] In the present invention, the concentration of the first organic material in the mixed solution is preferably 1 to 5 mg / mL, more preferably 1 mg / mL.

[0089] In the present invention, the rotation speed of spin coating is preferably 800 - 6000 rpm, more preferably 4000 - 5000 rpm; the time is preferably 5 - 120 s, more preferably 20 - 30 s.

[0090] In the present invention, when the second organic material is included in the electron transport layer, the second organic material includes an organic polymer or an organic small molecule material; the organic polymer includes one or more of poly(triphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinylpyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, poly(dimethyldiallylammonium chloride), poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene, and poly(3-hexylthiophene-2,5-diyl). When there are two or more of the above specific choices for the organic polymer, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio. In the present invention, the organic small molecule material is preferably an n-type organic semiconductor material, and the n-type organic semiconductor material preferably includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline), bathophenanthroline, 1,3,5-tris(1-phenyl-1H-benzoimidazol-2-yl)benzene, 1,3,5-tris(3-pyridyl-3-phenyl)benzene, 2,4,6-tris[3-(diphenylphosphoryloxy)phenyl]-1,3,5-triazole, 2,4,6-tris(1,1'-biphenyl)-1,3,5-triazine, and bathocuproine. When there are two or more of the above specific choices for the organic small molecule material, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0091] In the present invention, the mass ratio of the inorganic metal oxide nanoparticles to the organic material is preferably (5 - 20):(2 - 5), more preferably (10 - 15):(3 - 4).

[0092] In the present invention, the thickness of the electron transport layer is preferably 20 - 50 nm, more preferably 40 nm.

[0093] In the present invention, the preparation method of the electron transport layer preferably includes the following steps:

[0094] Mix inorganic metal oxide nanoparticles with a solvent to obtain a mixture; or mix inorganic metal oxide nanoparticles, a second organic material, and a solvent to obtain a mixture;

[0095] After spin-coating the mixture, form a film to obtain the electron transport layer.

[0096] In the present invention, the solvent is preferably one or more of isopropyl alcohol, ethanol, methanol, chloroform, acetonitrile, and ethyl acetate, and more preferably isopropyl alcohol; when the solvent is two or more of the above specific selections, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0097] The present invention does not have any special limitation on the mixing process, and it can be carried out using a process well-known to those skilled in the art.

[0098] In the present invention, the mass concentration of the inorganic metal oxide nanoparticles in the mixture is preferably 5-20%, more preferably 10-15%; the mass concentration of the second organic material in the mixture is preferably 2-5%, more preferably 3-4%.

[0099] In the present invention, the rotation speed of the spin-coating is preferably 4000-6000 rpm, more preferably 4500-5500 rpm; the time is preferably 30 s.

[0100] In the present invention, the film-forming method is preferably direct film-forming or annealing film-forming. The temperature of the annealing film-forming is preferably 80-150 °C, more preferably 110-140 °C; the time is preferably 1-30 min, more preferably 10-15 min.

[0101] In the present invention, the thickness of the electrode layer is preferably 80-150 nm, more preferably 90-120 nm. In the present invention, the material of the electrode layer is preferably silver or copper. In the present invention, the preparation of the electrode layer preferably adopts the evaporation method, and the present invention does not have any special limitation on the process of the evaporation method, and it can be carried out using a process well-known to those skilled in the art.

[0102] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0103] Example 1

[0104] The ITO transparent conductive substrate was ultrasonically cleaned with glass cleaner, deionized water, acetone and isopropanol in sequence for 15 min, and then subjected to UV-O3 treatment for 15 min to obtain the pretreated ITO glass;

[0105] A hole transport layer was spin-coated on the surface of the pretreated ITO glass: after the surface of the pretreated ITO glass was covered with a self-assembled monolayer material solution (the self-assembled monolayer material was [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), with a concentration of 0.3 mg / mL), wait for 10 min and then spin-coat. The rotation speed of the spin-coating was 4000 rpm and the time was 30 s; after the spin-coating was completed, annealing was carried out at 100 °C for 10 min, cooled, and the self-assembled monolayer material that failed to anchor to the pretreated ITO glass was washed away with isopropanol to obtain a hole transport layer (with a thickness of 3 nm);

[0106] A perovskite layer was prepared on the surface of the hole transport layer by an anti-solvent method: after 8 mg of MABr was dissolved in 1 mL of a solvent (a mixed solution of DMF and DMSO with a volume ratio of 4:1), the resulting solution was spin-coated on the surface of the hole transport layer (the spin-coating process was: first accelerate to a rotation speed of 1000 rpm at an acceleration of 1000 rpm / s and spin-coat for 10 s; then accelerate to a rotation speed of 3000 rpm at an acceleration of 3000 rpm / s and spin-coat for 30 s). At the 30th second of spin-coating, 150 μL of chlorobenzene (CB) was uniformly dropped at a dropping rate of 150 μL / s, and annealing was carried out at 100 °C for 15 min to obtain a perovskite layer (with a thickness of 800 nm);

[0107] An amine compound molecule treatment layer was prepared on the surface of the perovskite layer: an amine compound molecule (the types were methylamine iodide and ethylenediamine iodide) was dissolved in 1 mL of a solvent (a mixed solvent of IPA and DMF with a volume ratio of 20:1) to obtain a mixed solution (the concentration of methylamine iodide in the mixed solution was 10 mM, and the concentration of ethylenediamine iodide was 10 mM). The resulting mixed solution was spin-coated on the surface of the perovskite layer (the rotation speed of the spin-coating was 4000 rpm and the time was 30 s), and then annealing was carried out at 100 °C for 5 min to obtain an amine compound molecule treatment layer (with a thickness of 5 nm);

[0108] An interfacial buffer layer was prepared on the surface of the amine compound molecule treatment layer: a solution of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthraquinonyl[2,1,9-def:6,5,10-d'e'f']diisoquinoline (PDINN) with a concentration of 1 mg / mL (the solvent was ethanol) was spin-coated on the surface of the amine compound molecule treatment layer (the rotation speed of the spin-coating was 3000 rpm and the time was 30 s) to obtain an interfacial buffer layer (with a thickness of 5 nm);

[0109] Fabricate an electron transport layer on the surface of the interface buffer layer: Disperse indium tin oxide nanoparticles (ITO-NPs) in isopropanol to obtain an indium tin oxide dispersion with a mass concentration of 5%. After spin-coating the indium tin oxide dispersion on the surface of the interface buffer layer (spin-coating speed: 4000 rpm, time: 30 s), anneal at 100 °C for 5 min to obtain an electron transport layer (thickness: 40 nm).

[0110] Evaporate a silver electrode with a thickness of 100 nm on the surface of the electron transport layer to obtain a perovskite solar cell (structure: ITO / MeO-2PACz / Perovskite / post-treatment / PDINN / ITO-NPs / Ag).

[0111] Example 2

[0112] Ultrasonically clean the ITO transparent conductive substrate successively with glass cleaner, deionized water, acetone, and isopropanol for 15 min, and then perform UV-O3 treatment for 15 min to obtain a pretreated ITO glass.

[0113] Spin-coat a hole transport layer on the surface of the pretreated ITO glass: Spread a self-assembled monolayer material solution (self-assembled monolayer material: [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), concentration: 0.3 mg / mL) on the surface of the pretreated ITO glass and wait for 10 min before spin-coating. The spin-coating speed is 4000 rpm, and the time is 30 s. After spin-coating, anneal at 100 °C for 10 min, cool, and wash away the self-assembled monolayer material that fails to anchor to the pretreated ITO glass with isopropanol to obtain a hole transport layer (thickness: 3 nm).

[0114] Fabricate a perovskite layer on the surface of the hole transport layer by the anti-solvent method: Dissolve 8 mg of MABr in 1 mL of solvent (a mixed solution of DMF and DMSO with a volume ratio of 4:1), and then spin-coat the resulting solution on the surface of the hole transport layer (spin-coating process: First, accelerate to a speed of 1000 rpm at an acceleration rate of 1000 rpm / s and spin-coat for 10 s; then, accelerate to a speed of 3000 rpm at an acceleration rate of 3000 rpm / s and spin-coat for 30 s). At the 30th second of spin-coating, uniformly drip 150 μL of chlorobenzene (CB) at a drip rate of 150 μL / s, and anneal at 100 °C for 15 min to obtain a perovskite layer (thickness: 800 nm).

[0115] Prepare an amine compound molecule treatment layer on the surface of the perovskite layer: Dissolve amine compound molecules (types are methylamine iodide and ethylenediamine iodide) in 1 mL of a solvent (a mixed solvent of IPA and DMF with a volume ratio of 20:1) to obtain a mixed solution (the concentration of methylamine iodide in the mixed solution is 10 mM, and the concentration of ethylenediamine iodide is 10 mM). Spin-coat the obtained mixed solution on the surface of the perovskite layer (the spinning speed is 4000 rpm and the time is 30 s), and then anneal at 100 °C for 5 min to obtain an amine compound molecule treatment layer (with a thickness of 5 nm);

[0116] Prepare an electron transport layer on the surface of the amine compound molecule treatment layer: Disperse indium tin oxide nanoparticles (ITO-NPs) and polyvinyl alcohol (PVA) in isopropyl alcohol to obtain a dispersion (the mass concentration of indium tin oxide nanoparticles in the dispersion is 10%, and the mass concentration of polyvinyl alcohol is 5%); Spin-coat the indium tin oxide dispersion on the surface of the electron transport layer (the spinning speed is 4000 rpm and the time is 30 s), and then anneal at 100 °C for 5 min to obtain an electron transport layer (with a thickness of 40 nm);

[0117] Evaporate a silver electrode with a thickness of 100 nm on the surface of the electron transport layer to obtain a perovskite solar cell (structure: ITO / MeO-2PACz / Perovskite / post-treatment / ITO-NPs+PVA / Ag).

[0118] Example 3

[0119] Ultrasonically clean the ITO transparent conductive substrate successively with glass cleaner, deionized water, acetone and isopropyl alcohol for 15 min, and then perform UV-O3 treatment for 15 min to obtain a pretreated ITO glass;

[0120] Spin-coat a hole transport layer on the surface of the pretreated ITO glass: Spread a self-assembled monolayer material solution (the self-assembled monolayer material is [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphonic acid (MeO-2PACz), with a concentration of 0.3 mg / mL) on the surface of the pretreated ITO glass and wait for 10 min for spin-coating. The spinning speed is 4000 rpm and the time is 30 s; After the spin-coating is completed, anneal at 100 °C for 10 min, cool, and wash away the self-assembled monolayer material that fails to anchor to the pretreated ITO glass with isopropyl alcohol to obtain a hole transport layer (with a thickness of 3 nm);

[0121] The perovskite layer is prepared on the surface of the hole transport layer by the anti-solvent method: 8 mg of MABr is dissolved in 1 mL of a solvent (a mixed solution of DMF and DMSO with a volume ratio of 4:1), and then the resulting solution is spin-coated on the surface of the hole transport layer (the spin-coating process is as follows: first, the speed is increased to 1000 rpm at an acceleration of 1000 rpm / s and spin-coated for 10 s; then, the speed is increased to 3000 rpm at an acceleration of 3000 rpm / s and spin-coated for 30 s). At the 30th second of spin-coating, 150 μL of chlorobenzene (CB) is uniformly added dropwise at a dropping rate of 150 μL / s, and annealed at 100 °C for 15 min to obtain the perovskite layer (with a thickness of 800 nm);

[0122] An amine compound molecule treatment layer is prepared on the surface of the perovskite layer: The amine compound molecules (methylamine iodide and ethylenediamine iodide) are dissolved in 1 mL of a solvent (a mixed solvent of IPA and DMF with a volume ratio of 20:1) to obtain a mixed solution (the concentration of methylamine iodide in the mixed solution is 10 mM, and the concentration of ethylenediamine iodide is 10 mM). After the resulting mixed solution is spin-coated on the surface of the perovskite layer (the spin-coating speed is 4000 rpm and the time is 30 s), it is annealed at 100 °C for 5 min to obtain the amine compound molecule treatment layer (with a thickness of 5 nm);

[0123] An interfacial buffer layer is prepared on the surface of the perovskite layer: A solution of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthra[2,1,9-def:6,5,10-d'e'f']diisoquinoline (PDINN) with a concentration of 1 mg / mL (the solvent is ethanol) is spin-coated on the surface of the amine compound molecule treatment layer (the spin-coating speed is 3000 rpm and the time is 30 s) to obtain the interfacial buffer layer (with a thickness of 5 nm);

[0124] An electron transport layer is prepared on the surface of the interfacial buffer layer: Indium tin oxide nanoparticles (ITO-NPs) and polyvinyl alcohol (PVA) are dispersed in isopropyl alcohol to obtain a dispersion (the mass concentration of indium tin oxide nanoparticles in the dispersion is 10%, and the mass concentration of polyvinyl alcohol is 5%); After the indium tin oxide dispersion is spin-coated on the surface of the electron transport layer (the spin-coating speed is 4000 rpm and the time is 30 s), it is annealed at 100 °C for 5 min to obtain the electron transport layer (with a thickness of 40 nm);

[0125] A silver electrode with a thickness of 100 nm is evaporated on the surface of the electron transport layer to obtain a perovskite solar cell (the structure is:

[0126] ITO / MeO-2PACz / Perovskite / post-treatment / PDINN / ITO-NPs+PVA / Ag)。

[0127] Comparative Example 1

[0128] Referring to Reference Example 1, the difference is that: after the preparation of the amine compound molecule treatment layer, a PCBM layer, a BCP layer, and a silver layer are sequentially prepared on the surface of the amine compound molecule treatment layer;

[0129] The preparation process of the PCBM layer is as follows: A solution of PCBM ([6,6]-phenyl-C61-butyric acid methyl ester) with a concentration of 20 mg / mL (the solvent is chlorobenzene) is spin-coated on the surface of the amine compound molecule treatment layer (the spin-coating speed is 1000 rpm and the time is 30 s) to obtain an electron transport layer (with a thickness of 50 nm);

[0130] The preparation process of the BCP layer is as follows: A solution of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) with a concentration of 1 mg / mL (the solvent is ethanol) is spin-coated on the surface of the PCBM layer (the spin-coating speed is 3000 rpm and the time is 30 s) to obtain an interface layer (with a thickness of 5 nm);

[0131] The preparation of the silver layer refers to Reference Example 1;

[0132] The structure of the prepared perovskite solar cell is ITO / MeO-2PACz / Perovskite / post-treatment / PCBM / BCP / Ag.

[0133] Comparative Example 2

[0134] Referring to Comparative Example 1, the difference is that: the preparation of the amine compound molecule treatment layer is omitted, and the structure of the prepared perovskite solar cell is ITO / MeO-2PACz / Perovskite / PCBM / BCP / Ag.

[0135] Figure 1 Figure 28 shows the J-V curves of the perovskite solar cells described in Example 1 and Comparative Example 1, where Control is the perovskite solar cell described in Comparative Example 1 and Target is the perovskite solar cell described in Example 1; It can be seen that Figure 1 after using ITO nanoparticles as the electron transport layer and performing interface treatment, ITO nanoparticles can have a more matched energy level structure with perovskite, have stronger electron extraction ability, effectively transport electrons at the same time, increase the current density, and improve the device efficiency;

[0136] Figure 2J-V curves of the perovskite solar cells described in Example 2 and Comparative Example 1, where Control is the perovskite solar cell described in Comparative Example 1 and Target is the perovskite solar cell described in Example 2; from Figure 2 It can be seen that after using ITO nanoparticles as the electron transport layer and doping with polymer materials, the combination between ITO nanoparticles and the perovskite layer is stronger, the ITO nanoparticles are closely arranged, which can cover some pinholes on the perovskite surface, effectively extract and transport electrons, resulting in an increase in current density and device efficiency;

[0137] Figure 3 J-V curves of the perovskite solar cells described in Example 3 and Comparative Example 2, where Control is the perovskite solar cell described in Comparative Example 2 and Target is the perovskite solar cell described in Example 3; from Figure 3 It can be seen that by using ITO nanoparticles as the electron transport layer, doping with polymer materials, and performing interface treatment at the same time, the concentration and lifetime of electrons can be effectively improved. Therefore, the current density and open-circuit voltage increase, and the device efficiency is improved.

[0138] The above are only the preferred embodiments of the present invention and do not impose any form of limitation on the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A perovskite solar cell, characterized in that: It includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer and an electrode layer which are stacked in sequence; The material of the electron transport layer is inorganic metal oxide nanoparticles; The electron transport layer is prepared by a solution method; An interface buffer layer is further included between the perovskite layer and the electron transport layer, and the material of the interface buffer layer is a first organic material; and / or the material of the electron transport layer also includes a second organic material; The first organic material and the second organic material independently include organic polymers and / or organic small molecule materials; The organic polymer includes one or more of polytriphenylamine, poly[bis(4-phenyl)(4-butylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyvinyl alcohol, sodium polystyrene sulfonate, polyvinyl pyrrolidone, polycarbonate, polyethyleneimine, polyacrylamide, polymethyl methacrylate, polydimethyldiallylamine chloride, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)], polyaniline, polythiophene, polyfluorene and poly(3-hexylthiophene-2,5-diyl); The organic small molecule material includes an n-type organic semiconductor material; the n-type organic semiconductor material includes one or more of 2,9-bis(3-((3-(dimethylamino)propyl)amino)propyl)-3,3'-(1,3,8,10-tetraanthraquinone[2,1,9-def:6,5,10-d'e'f']diisoquinoline, bathophenanthroline, 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene, 1,3,5-tri(3-pyridyl-3-phenyl)benzene, 2,4,6-tri[3-(diphenylphosphinoyl)phenyl]-1,3,5-triazole, 2,4,6-tri(1,1'-biphenyl)-1,3,5-triazine and bathocuproin.

2. The perovskite solar cell according to claim 1, characterized in that An amine compound molecule treatment layer is further provided between the perovskite layer and the interface buffer layer, or an amine compound molecule treatment layer is further provided between the perovskite layer and the electron transport layer.

3. The perovskite solar cell according to claim 2, characterized in that The method for preparing the amine compound molecular treatment layer comprises the following steps: Mixing amine compound molecules and a solvent to obtain a mixed solution; or mixing amine compound molecules, an organic material and a solvent to obtain a mixed solution; The mixed solution is coated on the surface of the perovskite layer to form a film, thereby obtaining the amine compound molecule treatment layer.

4. The perovskite solar cell according to claim 3, characterized in that The amine compound molecules include one or more of methylamine iodine, methylamine chloride, methylamine bromide, formamidine iodine, formamidine chloride, formamidine bromide, 3-methylthio-1-propylamine iodine, 3-methylthio-1-propylamine chloride, 3-methylthio-1-propylamine bromide, butylamine iodine, butylamine chloride, butylamine bromide, propylenediamine iodine, propylenediamine chloride, propylenediamine bromide, ethylenediamine iodine, ethylenediamine chloride, ethylenediamine bromide, benzylamine iodine, benzylamine chloride, benzylamine bromide, phenethylamine iodine, phenethylamine chloride, phenethylamine bromide, methoxybenzylamine iodine, methoxybenzylamine chloride, methoxybenzylamine bromide, methoxyphenethylamine iodine, methoxyphenethylamine chloride and methoxyphenethylamine bromide; The solvent includes one or more of isopropanol, chlorobenzene and N,N-dimethylformamide; The concentration of the amine compound molecules in the mixed solution is 5 to 20 mmol / L; The coating method is spin coating, the spin coating speed is 800-5000 rpm, and the time is 10-120 s; The film forming method is direct film forming or annealing film forming, and the annealing film forming temperature is 80 to 150° C. and the time is 5 to 10 minutes.

5. The perovskite solar cell according to claim 1, characterized in that The method for preparing the interface buffer layer comprises the following steps: The first organic material is mixed with a solvent, and the obtained mixed solution is spin-coated to obtain the interface buffer layer.

6. The perovskite solar cell according to claim 5, characterized in that The concentration of the first organic material in the mixed solution is 1 to 5 mg / mL; The spin coating has a rotation speed of 800 to 6000 rpm and a time of 5 to 120 seconds.

7. The perovskite solar cell according to claim 1, characterized in that When the material of the electron transport layer further includes a second organic material, the mass ratio of the inorganic metal oxide nanoparticles to the second organic material is (5-20):(2-5).

8. The perovskite solar cell according to claim 1 or 7, characterized in that: The method for preparing the electron transport layer comprises the following steps: Mixing inorganic metal oxide nanoparticles with a solvent to obtain a mixed solution; or mixing inorganic metal oxide nanoparticles, a second organic material and a solvent to obtain a mixed solution; The mixed solution is spin-coated to form a film, thereby obtaining the electron transport layer.

9. The perovskite solar cell according to claim 8, characterized in that The solvent includes one or more of isopropanol, ethanol, methanol, chloroform, acetonitrile and ethyl acetate; The mass concentration of the inorganic metal oxide nanoparticles in the mixed solution is 5 to 20%; The mass concentration of the second organic material in the mixed solution is 2-5%.

10. The perovskite solar cell according to claim 8, characterized in that: The spin coating has a rotation speed of 4000-6000 rpm and a time of 30 s; The film forming method is direct film forming or annealing film forming, and the annealing film forming temperature is 80 to 150° C. and the time is 1 to 30 minutes.

Images