Perovskite material, perovskite solar cell and preparation method of perovskite solar cell

Abstract

The invention belongs to the technical field of perovskite photoelectric materials, and particularly relates to a perovskite material, a perovskite solar cell and a preparation method of the perovskite solar cell. The perovskite material provided by the invention comprises the following chemical components: organic groups, metal cations, halogen anions and ammonium ions, the organic groups comprise a first organic group and a second organic group; the first organic group is CH3NH < 3 + > or CH3NHNH < 3 + >; and the second organic group is 8-anilino-1-naphthalene sulfonate radical. The perovskite material provided by the invention has good hydrophobic function, chemical inertness and stability. According to the perovskite solar cell, the perovskite material is applied to the perovskite solar cell, the stability of long-term operation of the perovskite solar cell can be improved, and the problems of erosion and ion migration of the perovskite solar cell are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optoelectronic materials, and particularly relates to a perovskite material, a perovskite solar cell and a preparation method thereof. Background Art

[0002] Perovskite optoelectronic materials refer to a class of compounds with an ABX 3 structure, where the A site is a certain organic group, the B site is a metal cation, and the X site is usually a halogen anion. This perovskite optoelectronic material composed of an organic group and inorganic elements is called an organic-inorganic hybrid perovskite. Representative organic-inorganic hybrid perovskite materials include CH 3 NH 3 PbI 3 and CH 3 NH 3 PbBr 3 etc. Taking CH 3 NH 3 PbI 3 as an example, in an ideal perovskite crystal form, Pb and 6 I form a [PbI 6 octahedron, and 8 [PbI 6 octahedrons are connected by sharing vertices in three-dimensional space to form a network framework. CH 3 NH 3 + is located in the very middle of the three-dimensional network, playing a role in balancing the perovskite spatial structure. Due to this special phase structure of perovskite, the organic-inorganic hybrid material can not only enable ions with very different radii to coexist stably, but also endow itself with many excellent electrochemical properties, including a narrow bandgap width, a high absorption coefficient, a high carrier mobility and diffusion length, etc. These characteristics make perovskite materials excellent light-trapping materials and are widely used in perovskite solar cells.

[0003] A perovskite solar cell generally consists of a substrate, an electron transport layer (electron selective absorption layer), a perovskite layer, a hole transport layer (hole selective absorption layer) and a metal electrode. Among them, the perovskite layer made of perovskite optoelectronic material is the core functional layer of the entire perovskite solar cell. The working principle of the perovskite solar cell is as follows: after the perovskite layer is irradiated by incident light, electron-hole pairs are generated by excitation. Under the drive of the built-in electric field in the n-i-p structure, electrons are injected from the conduction band of the perovskite optoelectronic material into the electron transport layer and transported to the substrate, and the holes pass through the perovskite layer and are extracted by the metal electrode. If a load is connected, a complete circuit can be formed to supply power externally.

[0004] Although perovskite solar cells have excellent optoelectronic properties, their long-term operation stability is not satisfactory in practical applications. Summary of the Invention

[0005] The object of the present invention is to provide a perovskite material, a perovskite solar cell and a preparation method thereof. The perovskite material provided by the present invention is applied to a perovskite solar cell, improving the long-term operation stability of the perovskite solar cell.

[0006] To achieve the above object of the invention, the present invention provides the following technical solutions:

[0007] A perovskite material, the chemical composition of which includes an organic group, a metal cation, a halogen anion and an ammonium ion; the organic group includes a first organic group and a second organic group; the first organic group is CH 3 NH 3 + or CH 3 NHNH 3 + ; the second organic group is 8-anilino-1-naphthalenesulfonate.

[0008] Preferably, the metal cation includes Pb 2+ ; the halogen anion includes Cl - , Br - or I - .

[0009] The present invention provides a preparation method of the perovskite material described in the above technical solution, including the following steps:

[0010] Mix a metal halide, an organic halide and an organic solvent to obtain a mixed solution; the organic halide is a compound formed by the first organic group and a halogen;

[0011] Mix the mixed solution with 8-anilino-1-naphthalenesulfonic acid ammonium salt to obtain a perovskite precursor solution;

[0012] Dry the perovskite precursor solution to obtain a precursor; perform annealing treatment on the precursor to obtain the perovskite material.

[0013] Preferably, the molar ratio of the metal halide to the organic halide is 1:1; the total concentration of the metal halide and the organic halide in the mixed solution is 450-470 mg / mL; the content of 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite precursor solution is 0.05-3 wt%.

[0014] Preferably, the annealing treatment includes performing first annealing and second annealing in sequence; the temperature of the first annealing is 40-60 °C, and the heat preservation time is 25-45 s; the temperature of the second annealing is 100-120 °C, and the heat preservation time is 3-10 min.

[0015] The present invention provides a perovskite solar cell, which comprises a substrate, an electron transport layer, a first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer, a perovskite layer, a second 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer, a hole transport layer and a metal electrode which are stacked in sequence; the material of the perovskite layer is the perovskite material described in the above technical solution or the perovskite material prepared by the preparation method described in the above technical solution.

[0016] Preferably, the material of the electron transport layer includes SnO 2 , ZnO, TiO 2 or NiO; the material of the metal electrode includes Au or Ag.

[0017] Preferably, the thickness of the electron transport layer is 30-80 nm; the thickness of the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer is 10-15 nm; the thickness of the perovskite layer is 350-600 nm; the thickness of the second 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer is 15-20 nm; the thickness of the hole transport layer is 100-200 nm; the thickness of the metal electrode is 140-160 nm.

[0018] The present invention provides a preparation method of the perovskite solar cell described in the above technical solution, which comprises the following steps:

[0019] Construct the electron transport layer and the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer on one side of the substrate in sequence;

[0020] Mix metal halide, organic halide, organic solvent and 8-anilinonaphthalene-1-sulfonic acid ammonium salt to obtain a perovskite precursor solution; coat the perovskite precursor solution on the surface of the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer and perform annealing treatment to form a perovskite layer on the surface of the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer;

[0021] Construct the second 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer, the hole transport layer and the metal electrode on the surface of the perovskite layer in sequence to obtain the perovskite solar cell.

[0022] Preferably, the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer is formed by a first 8-anilinonaphthalene-1-sulfonic acid ammonium salt solution, and the second 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer is formed by a second 8-anilinonaphthalene-1-sulfonic acid ammonium salt solution; the concentration of the first 8-anilinonaphthalene-1-sulfonic acid ammonium salt solution is 0.005-0.1 wt%; the concentration of the second 8-anilinonaphthalene-1-sulfonic acid ammonium salt solution is 0.05-0.3 wt%.

[0023] The present invention provides a perovskite material, the chemical composition of which includes an organic group, a metal cation, a halogen anion, and an ammonium ion; the organic group includes a first organic group and a second organic group; the first organic group is CH 3 NH 3 + or CH 3 NHNH 3 + ; the second organic group is 8-anilino-1-naphthalenesulfonate. The present invention introduces 8-anilinonaphthalene-1-sulfonic acid ammonium salt into the perovskite material to construct a perovskite material with a mixed two-dimensional and three-dimensional structure. In the 8-anilinonaphthalene-1-sulfonic acid ammonium salt added in the present invention, the benzene ring and naphthalene ring have good hydrophobic ability and chemical inertness, which can block the erosion of moisture and oxygen in the environment to the inside of the perovskite material; moreover, the chemical structure of the 8-anilinonaphthalene-1-sulfonic acid ammonium salt contains a sulfonate group and an ammonium salt that are easy to bond with metal halides, which can improve the stability of the perovskite material and effectively reduce the ion migration inside the perovskite material.

[0024] The present invention provides a perovskite solar cell, which includes a substrate, an electron transport layer, a first 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer, a perovskite layer, a second 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer, a hole transport layer, and a metal electrode stacked in sequence; the perovskite layer is the perovskite material provided by the present invention. The present invention respectively adds an 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layer between two interfaces of the electron transport layer and the perovskite layer and between the perovskite layer and the hole transport layer; the 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layers at the two interfaces can serve as a waterproof barrier to protect the middle perovskite layer from the interference of water vapor in the atmosphere, and solve the problem of the perovskite solar cell failing in water; moreover, the two 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layers of the present invention together with the 8-anilinonaphthalene-1-sulfonic acid ammonium salt in the perovskite layer bulk phase can block the migration of halogen ions or cations inside the perovskite material under the action of light and heat, and solve the problem of the perovskite solar cell failing due to ion migration. In addition, the present invention can utilize the bonding of the sulfonate group and ammonium salt in the 8-anilinonaphthalene-1-sulfonic acid ammonium salt molecule structure in the two 8-anilinonaphthalene-1-sulfonic acid ammonium salt passivation layers with metal cations and halogen anions to ensure the rapid circulation of photo-generated carriers in the perovskite solar cell, which is beneficial to improving the optoelectronic performance of the perovskite solar cell and enhancing the stability of the long-term operation of the perovskite solar cell.

[0025] Furthermore, the preparation method of the perovskite solar cell provided by the present invention is simple to operate, has high preparation safety, low cost, and can be industrially produced. Description of the Drawings

[0026] Figure 1Molecular structure diagram of ammonium 8 - anilino - 1 - naphthalenesulfonate;

[0027] Figure 2 is CH 3 NH 3 PbI 3 Crystal structure diagram of perovskite;

[0028] Figure 3 Schematic structural diagram of the perovskite solar cell in Example 1 of the present invention. Detailed implementation mode

[0029] The present invention provides a perovskite material, the chemical composition of which includes an organic group, a metal cation, a halogen anion and an ammonium ion; the organic group includes a first organic group and a second organic group; the first organic group is CH 3 NH 3 + or CH 3 NHNH 3 + ; the second organic group is 8 - anilino - 1 - naphthalenesulfonate.

[0030] In the prior art, the organic group and the inorganic group in the perovskite material are combined by van der Waals forces, and this soft lattice feature makes its structure inherently unstable. The present invention introduces ammonium 8 - anilino - 1 - naphthalenesulfonate into the perovskite material to construct a perovskite material with a mixed two - dimensional and three - dimensional structure. In the ammonium 8 - anilino - 1 - naphthalenesulfonate added in the present invention, the benzene ring and the naphthalene ring have good hydrophobic ability and chemical inertness, which can block the erosion of moisture and oxygen in the environment to the inside of the perovskite material; moreover, the chemical structure of ammonium 8 - anilino - 1 - naphthalenesulfonate contains a sulfonate group and an ammonium salt that are easy to bond with metal halides, which can improve the stability of the perovskite material and effectively reduce the ion migration inside the perovskite material. The perovskite material provided by the present invention will be described in detail below.

[0031] In the present invention, unless otherwise specified, all preparation raw materials / components are commercially available products well - known to those skilled in the art.

[0032] As an implementation mode of the present invention, the metal cation includes Pb 2+ ; the halogen anion includes Cl - , Br - or I - .

[0033] As an implementation mode of the present invention, the molar ratio of the first organic group to the second organic group can be 1:0.10 - 5.92, and further can be 1:0.5 - 4.

[0034] The present invention provides a method for preparing the perovskite material described in the above technical solution, comprising the following steps:

[0035] Mix a metal halide, an organic halide, and an organic solvent to obtain a mixed solution; the organic halide is a compound formed by a first organic group and a halogen.

[0036] Mix the mixed solution with 8-anilino-1-naphthalenesulfonic acid ammonium salt to obtain a perovskite precursor solution.

[0037] Dry the perovskite precursor solution to obtain a precursor; anneal the precursor to obtain the perovskite material.

[0038] The present invention mixes a metal halide, an organic halide, and an organic solvent to obtain a mixed solution.

[0039] As an embodiment of the present invention, the metal halide may include PbI 2 , PbCl 2 or PbBr 2 . The organic halide in the present invention is a compound formed by a first organic group and a halogen, and specifically may include CH 3 NH 3 I 2 , CH 3 NH 3 Cl 2 , CH 3 NH 3 Br 2 , CH 3 NHNH 3 I 2 , CH 3 NHNH 3 Cl 2 or CH 3 NHNH 3 Br 2 .

[0040] As an embodiment of the present invention, the organic solvent may include DMF.

[0041] As an embodiment of the present invention, the molar ratio of the metal halide to the organic halide is 1:1.

[0042] As an embodiment of the present invention, the total concentration of the metal halide and the organic halide in the mixed solution may be 450-470 mg / mL, specifically 460 mg / mL.

[0043] As an embodiment of the present invention, the mixing of the metal halide, the organic halide and the organic solvent can be carried out under heating and stirring conditions; the temperature of the heating and stirring can be 25 to 80 °C, further can be 65 to 80 °C, specifically can be 70 °C; the time of the heating and stirring can be 3 to 6 h, specifically can be 5 h; the present invention has no special limitation on the rotation speed of the heating and stirring, and the rotation speed well-known to those skilled in the art can be adopted.

[0044] After obtaining the mixed solution, the present invention mixes the mixed solution with 8-anilino-1-naphthalenesulfonic acid ammonium salt to obtain a perovskite precursor solution.

[0045] As an embodiment of the present invention, the content of 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite precursor solution can be 0.05 to 3 wt%, further can be 1 to 2 wt%.

[0046] The present invention controls the dosage of 8-anilino-1-naphthalenesulfonic acid ammonium salt within the above range, which can control the doping amount of 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite material, is beneficial to improving the stability and hydrophobicity of the perovskite material, and effectively reduces the ion migration inside the perovskite material.

[0047] The present invention has no special limitation on the mixing method of the mixed solution and 8-anilino-1-naphthalenesulfonic acid ammonium salt, and sufficient mixing can be achieved. As an embodiment of the present invention, after mixing the mixed solution with 8-anilino-1-naphthalenesulfonic acid ammonium salt, filtration may further be included, and the filtration may be filtration with a 200 nm filter head to obtain a perovskite precursor solution.

[0048] After obtaining the perovskite precursor solution, the present invention dries the perovskite precursor solution to obtain a precursor; and anneals the precursor to obtain the perovskite material.

[0049] As an embodiment of the present invention, the present invention has no special limitation on the drying, and only the solvent needs to be removed.

[0050] As an embodiment of the present invention, the annealing treatment may include first annealing and second annealing in sequence; the temperature of the first annealing can be 40 to 60 °C, specifically can be 50 °C; the heat preservation time of the first annealing can be 25 to 45 s, specifically can be 35 s; the temperature of the second annealing can be 100 to 120 °C, specifically can be 120 °C; the heat preservation time of the second annealing can be 3 to 10 min, specifically can be 5 min.

[0051] The annealing treatment of the present invention is beneficial to the formation of perovskite materials. Through two stages of nucleation and growth, the growth and crystallization of perovskite materials are reasonably controlled, thereby improving their optoelectronic properties. By controlling the time and temperature of the staged annealing treatment, the present invention can better control the growth of perovskite materials, improve the uniformity and coverage of perovskite materials; optimize the crystallization quality and crystal structure of perovskite materials, thereby improving the photoelectric conversion efficiency and service life of the battery.

[0052] The present invention provides a perovskite solar cell, including a substrate, an electron transport layer, a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a perovskite layer, a second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a hole transport layer, and a metal electrode, which are sequentially stacked; the material of the perovskite layer is the perovskite material described in the above technical solution or the perovskite material prepared by the preparation method described in the above technical solution.

[0053] The perovskite solar cell provided by the present invention includes a substrate. As an embodiment of the present invention, the substrate can be a conductive transparent substrate, and the substrate can specifically include an FTO substrate, an ITO substrate, or an ITO-PEN substrate.

[0054] In the present invention, the substrate of the perovskite solar cell not only provides mechanical support, but also serves as part of the electrode to help collect and conduct current, and has good conductivity; moreover, the transparent substrate allows light to pass through and reach the electron transport layer, improving the photoelectric conversion efficiency; at the same time, the substrate has certain thermal stability to withstand the high-temperature treatment during the manufacturing process and the heat accumulation during operation, which is beneficial to extending the service life and reliability of the battery.

[0055] The perovskite solar cell provided by the present invention includes an electron transport layer stacked on one side of the substrate. As an embodiment of the present invention, the material of the electron transport layer can include SnO 2 , ZnO, TiO 2 or NiO; the thickness of the electron transport layer can be 30-80 nm, specifically 50-80 nm.

[0056] In the present invention, the electron transport layer of the perovskite solar cell can promote the transport of photo-generated electrons from the perovskite layer to the substrate, while blocking the reverse flow of holes; improving the charge separation efficiency and reducing charge recombination, thereby improving the photoelectric conversion efficiency of the battery.

[0057] The perovskite solar cell provided by the present invention includes a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer stacked on the surface of the electron transport layer. As an embodiment of the present invention, the thickness of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer can be 10-15 nm, specifically 8 nm.

[0058] The perovskite solar cell provided by the present invention includes a perovskite layer stacked on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer. As an embodiment of the present invention, the thickness of the perovskite layer can be 350-600 nm, specifically 400 nm.

[0059] The perovskite solar cell provided by the present invention includes a second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer stacked on the surface of the perovskite layer. As an embodiment of the present invention, the thickness of the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer can be 15-20 nm, specifically 16-18 nm.

[0060] The perovskite solar cell provided by the present invention includes a hole transport layer stacked on the surface of the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer. As an embodiment of the present invention, the hole transport layer can include a Spiro-OMeTAD hole transport layer; the thickness of the hole transport layer can be 100-200 nm, specifically 150 nm.

[0061] In the perovskite solar cell of the present invention, the hole transport layer can promote the transport of photo-generated holes from the perovskite layer to the metal electrode, while blocking the reverse flow of electrons; the hole transport layer and the electron transport layer act together to improve the charge separation efficiency and the stability of the battery.

[0062] The perovskite solar cell provided by the present invention includes a metal electrode stacked on the surface of the hole transport layer. As an embodiment of the present invention, the metal electrode can include an Au electrode or an Ag electrode; the thickness of the metal electrode can be 140-160 nm, specifically 150 nm.

[0063] In the perovskite solar cell of the present invention, the metal electrode collects the holes transported by the hole transport layer, forms a complete current loop, ensures the effective collection and transmission of the current, and realizes the output of electric energy.

[0064] The two 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layers provided by the present invention can serve as a waterproof barrier to protect the middle perovskite layer from the interference of water vapor in the atmosphere, and solve the problem of the failure of the perovskite solar cell in water; moreover, the two 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layers of the present invention together with the 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite layer bulk can block the migration of halogen ions or cations inside the perovskite material under the action of light and heat, and solve the problem of the failure of the perovskite solar cell caused by ion migration.

[0065] The present invention provides a preparation method of the perovskite solar cell according to the above technical solution, including the following steps:

[0066] An electron transport layer and a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer are sequentially stacked and constructed on one side of the substrate.

[0067] A metal halide, an organic halide, an organic solvent and 8-anilino-1-naphthalenesulfonic acid ammonium salt are mixed to obtain a perovskite precursor solution; the perovskite precursor solution is coated on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, and annealing treatment is carried out to form a perovskite layer on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer.

[0068] A second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a hole transport layer and a metal electrode are sequentially constructed on the surface of the perovskite layer to obtain the perovskite solar cell.

[0069] In the present invention, an electron transport layer and a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer are sequentially stacked and constructed on one side of the substrate.

[0070] As an embodiment of the present invention, the substrate can be pretreated, and the pretreatment can include: rubbing and cleaning the substrate with a cleaner, then sequentially performing ultrasonic cleaning with deionized water, acetone and ethanol, drying the cleaned substrate, and then performing ultraviolet ozone treatment. The time of the ultrasonic cleaning can be 30-50 min, specifically 40 min; the drying is drying, and the drying temperature can be 70-90 °C, specifically 80 °C; the time of the ultraviolet ozone treatment can be 10-20 min, specifically 15 min.

[0071] In the embodiment of the present invention, pretreating the substrate can remove pollutants and form a cleaner and flatter surface, which is beneficial to improving the bonding force between the substrate and the electron transport layer.

[0072] As an embodiment of the present invention, a metal oxide nanoparticle dispersion can be coated on the surface of the substrate and heat treatment is carried out to form an electron transport layer on the surface of the substrate.

[0073] As an embodiment of the present invention, the concentration of the metal oxide nanoparticle dispersion can be 2.4-2.6 wt%, specifically 2.5 wt%; the metal oxide nanoparticles in the metal oxide nanoparticle dispersion can specifically be SnO 2 , ZnO, TiO 2 or NiO.

[0074] As an embodiment of the present invention, the metal oxide nanoparticle dispersion can be obtained by diluting a metal oxide nanoparticle raw material solution; the concentration of the metal oxide nanoparticle raw material solution can be 4.5 - 5.5 wt%, specifically 5 wt%; the reagent used for dilution can be water, specifically deionized water; the dilution is carried out under stirring conditions, and the stirring time can be 2 - 4 h, specifically 3 h; the present invention has no special limitation on the temperature of the stirring, and it can be carried out at room temperature; the present invention has no special limitation on the rotation speed of the stirring, and a stirring rate well-known to those skilled in the art can be adopted.

[0075] As an embodiment of the present invention, when preparing the electron transport layer, the coating can be spin coating; the rotation speed of the spin coating can be 2000 - 5000 rpm, specifically 4000 rpm; the time of the spin coating can be 20 - 40 s, specifically 30 s.

[0076] As an embodiment of the present invention, the temperature of the heat treatment can be 150 - 200 °C, specifically 180 °C; the time of the heat treatment can be 10 - 20 min, specifically 15 min; the heat treatment can be carried out on a hot plate.

[0077] As an embodiment of the present invention, the preparation of the electron transport layer can be carried out in an 2 glove box.

[0078] As an embodiment of the present invention, after the electron transport layer is prepared, the present invention can coat a solution of 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt on the surface of the electron transport layer to form a 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer on the surface of the electron transport layer.

[0079] As an embodiment of the present invention, the solution of 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt can be prepared by mixing 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt with DMF.

[0080] As an embodiment of the present invention, the concentration of the solution of 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt can be 0.005 - 0.1 wt%, further 0.01 - 0.05 wt%.

[0081] The present invention controls the concentration of the solution of 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt within the above range, which can ensure that the obtained passivation film can cover the rough undulations of the substrate while the thickness of the passivation film will not increase excessively, so that the perovskite solar cell has good stability and high conversion efficiency, which is beneficial to improving the characteristics of the perovskite solar cell such as water resistance, oxygen resistance, light resistance and heat resistance, and effectively reducing the erosion and ion migration problems of the perovskite solar cell.

[0082] As an embodiment of the present invention, when preparing the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the coating is spin - coating. The rotation speed of the spin - coating can be 2000 - 5000 rpm, specifically 4000 rpm; the time of the spin - coating can be 5 - 20 s, specifically 10 s.

[0083] As an embodiment of the present invention, after the spin - coating, it may further include: blowing dry the solution along the direction parallel to the substrate at an inert gas flow rate of 3 - 10 MPa / min; the inert gas flow rate can be specifically 5 MPa / min; the inert gas can be N 2 。

[0084] After spin - coating in the present invention, by purging with nitrogen, the excess solvent can be quickly removed, enabling the first ammonium 8 - anilino - 1 - naphthalenesulfonate solution to form a uniform and dense passivation layer on the substrate, which is beneficial to controlling the thickness and uniformity of the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer.

[0085] After preparing the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the present invention mixes metal halide, organic halide, organic solvent and ammonium 8 - anilino - 1 - naphthalenesulfonate to obtain a perovskite precursor solution; the perovskite precursor solution is coated on the surface of the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer and annealed to form a perovskite layer on the surface of the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer.

[0086] The material of the perovskite layer in the present invention is the perovskite material prepared by the present invention. As an embodiment of the present invention, the perovskite layer can be a perovskite thin film.

[0087] As an embodiment of the present invention, when preparing the perovskite layer, the coating is spin - coating, and the spin - coating may include first spin - coating and second spin - coating in sequence; the rotation speed of the first spin - coating can be 800 - 1200 rpm, specifically 1000 rpm; the time of the first spin - coating can be 2 - 8 s, specifically 6 s; the rotation speed of the second spin - coating can be 2000 - 5000 rpm, specifically 4000 rpm; the time of the second spin - coating can be 30 - 40 s, specifically 35 s.

[0088] The present invention uses spin coating to evenly distribute the perovskite precursor solution coated on the substrate, forming a perovskite layer with a uniform thickness, which is beneficial to improving the photoelectric conversion efficiency and the stability of the battery. The spin coating of the present invention is divided into two steps, which can better control the size of perovskite grains, facilitate the formation of a more uniform and denser perovskite layer, reduce defects and amorphous regions, and thus improve the quality of the perovskite layer; moreover, by adjusting the spin coating speed and time, the present invention can precisely control the thickness of the perovskite layer.

[0089] As an embodiment of the present invention, the annealing treatment includes performing first annealing and second annealing in sequence; the temperature of the first annealing is 40 - 60 °C, specifically it can be 50 °C; the time of the first annealing is 25 - 45 s, specifically it can be 35 s; the temperature of the second annealing is 100 - 120 °C, specifically it can be 120 °C; the time of the second annealing is 3 - 10 min, specifically it can be 5 min.

[0090] As an embodiment of the present invention, the preparation of the perovskite layer can be carried out in 2 a glove box.

[0091] After the perovskite layer is prepared, the present invention will sequentially construct a second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer, a hole - transporting layer, and a metal electrode on the surface of the perovskite layer to obtain the perovskite solar cell.

[0092] As an embodiment of the present invention, the present invention can coat a second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt solution on the surface of the perovskite layer to form a second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer on the surface of the perovskite layer.

[0093] As an embodiment of the present invention, the second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt solution can be a mixture of 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt and DMF.

[0094] As an embodiment of the present invention, the concentration of the second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt solution can be 0.05 - 0.3 wt%, and further can be 0.1 - 0.3 wt%.

[0095] The present invention also prepares the second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer to prevent the polar solvent from damaging the mineral phase structure of the perovskite layer when the hole - transporting layer is prepared by the solution method. Therefore, compared with the first 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer, the present invention increases the concentration of the second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt solution and the thickness of the second 8 - anilino - 1 - naphthalenesulfonic acid ammonium salt passivation layer to further protect the perovskite layer structure.

[0096] As an embodiment of the present invention, when preparing the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the coating is spin - coating. The rotation speed of the spin - coating can be 2000 - 5000 rpm, specifically 4000 rpm; the time of the spin - coating can be 5 - 20 s, specifically 10 s.

[0097] As an embodiment of the present invention, after the spin - coating, it may further include: blowing dry the solution along the direction parallel to the substrate at an inert gas flow rate of 3 - 10 MPa / min; the inert gas flow rate is specifically 5 MPa / min; the inert gas is specifically N 2 。

[0098] As an embodiment of the present invention, after obtaining the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the present invention can mix 2,2',7,7'-tetrakis[N,N - bis(4 - methoxyphenyl)amino]-9,9'-spirobifluorene, tributyl phosphate, lithium bis(trifluoromethanesulfonyl)imide and an organic solvent to obtain a hole - transporting layer precursor solution; coat the hole - transporting layer precursor solution on the surface of the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer to form a hole - transporting layer on the surface of the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer.

[0099] As an embodiment of the present invention, the organic solvent can be acetonitrile and chlorobenzene; as an embodiment of the present invention, the present invention can dissolve lithium bis(trifluoromethanesulfonyl)imide (Li - TFSI) in acetonitrile to obtain a Li - TFSI stock solution; the concentration of the Li - TFSI stock solution can be 520 mg / mL; the present invention can stir - mix 2,2',7,7'-tetrakis[N,N - bis(4 - methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro - OMeTAD), tributyl phosphate (tBP), the Li - TFSI stock solution and chlorobenzene to obtain a hole - transporting layer precursor solution; the mass - to - volume ratio of Spiro - OMeTAD, tBP, the Li - TFSI stock solution and chlorobenzene can be 72.3 mg:28.8 μL:17.5 μL:1 mL; the time of the stir - mixing can be 1 - 3 h, specifically 2 h; the present invention has no special limitation on the temperature of the stir - mixing, and it can be carried out at room temperature; the present invention has no special limitation on the rotation speed of the stir - mixing, and the stirring rate well - known to those skilled in the art can be adopted.

[0100] As an embodiment of the present invention, when preparing the hole transport layer, the coating is spin coating; the rotation speed of the spin coating can be 2000-4000 rpm, specifically 3000 rpm; the time of the spin coating can be 10-30 s, specifically 20 s; the volume of the hole transport layer precursor solution during the spin coating can be 40-60 μL, specifically 50 μL.

[0101] As an embodiment of the present invention, after the hole transport layer is prepared, the present invention can evaporate a metal on the surface of the hole transport layer to form a metal electrode on the surface of the hole transport layer; thereby obtaining the perovskite solar cell.

[0102] As an embodiment of the present invention, the evaporation rate can be Specifically, it can be The evaporation can be carried out in a vacuum evaporator.

[0103] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0104] Example 1

[0105] (1) Cleaning of the FTO substrate

[0106] Rub and clean the FTO glass substrate with a cleaner, and perform ultrasonic cleaning for 40 min in turn with deionized water, acetone and ethanol. Then put the cleaned FTO glass substrate into an oven at 80 °C for drying and standby.

[0107] (2) Preparation of the SnO 2 Electron transport layer

[0108] Perform ultraviolet ozone treatment (UVO) on the cleaned FTO glass substrate for 15 min; take a 5 wt% SnO 2 nanoparticle dispersion, add deionized water for dilution, and the concentration of the diluted SnO 2 nanoparticle dispersion is 2.5 wt%; stir the diluted SnO 2 nanoparticle dispersion at room temperature for 3 h; spin coat the well-stirred SnO 2 nanoparticle dispersion evenly on the surface of the FTO substrate under the conditions of 4000 rpm and 30 s, and then place it on a hot plate at 180 °C for heat treatment. After 15 min, take it down to obtain SnO 2 electron transport layer on the FTO glass substrate, with a thickness of 80 nm; wherein the SnO 2 preparation of the electron transport layer is carried out in an N 2 glove box.

[0109] (3) Preparation of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer

[0110] Dissolve the 8-anilino-1-naphthalenesulfonic acid ammonium salt powder in DMF solvent to obtain an 8-anilino-1-naphthalenesulfonic acid ammonium salt solution with a concentration of 0.01 wt%; spin-coat the 8-anilino-1-naphthalenesulfonic acid ammonium salt solution on the surface of the SnO 2 electron transport layer for 10 s at 4000 rpm, and then quickly blow dry the solution at a nitrogen flow rate of 5 MPa / min along the direction parallel to the SnO 2 electron transport layer, and the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer with a thickness of 8 nm can be prepared on the SnO 2 electron transport layer.

[0111] (4) Preparation of the perovskite layer

[0112] Preparation method of the perovskite precursor solution: Mix equimolar amounts of PbI 2 and CH 3 NH 3 I in DMF solvent to prepare a 3 mL mixed solution with a total concentration of PbI 2 and CH 3 NH 3 I of 460 mg / mL, and stir magnetically at 70 °C for 5 h; add 42.12 mg of 8-anilino-1-naphthalenesulfonic acid ammonium salt to the mixed solution to make the content of 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite precursor solution 1 wt%, and then filter with a 200 nm filter head to obtain the perovskite precursor solution.

[0113] Preparation method of the perovskite layer: Take 30 μL of the perovskite precursor solution, spin-coat it for 6 s at 1000 rpm, and then spin-coat it for 35 s at 4000 rpm on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer; first anneal at 50 °C for 35 s, and then anneal at 120 °C for 5 min to prepare a perovskite layer with a thickness of 400 nm on the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer; where the preparation of the perovskite layer is carried out in an N 2 glove box.

[0114] (5) Preparation of the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer

[0115] The ammonium salt powder of 8-anilino-1-naphthalenesulfonic acid was dissolved in DMF solvent to obtain an ammonium salt solution of 8-anilino-1-naphthalenesulfonic acid with a concentration of 0.1 wt%. The ammonium salt solution of 8-anilino-1-naphthalenesulfonic acid was spin-coated on the surface of the perovskite layer at 4000 rpm for 10 s, and then the solution was quickly dried with a nitrogen flow rate of 5 MPa / min along the direction parallel to the perovskite layer, and a second ammonium salt passivation layer of 8-anilino-1-naphthalenesulfonic acid with a thickness of 18 nm was prepared on the perovskite layer.

[0116] (6) Preparation of Spiro-OMeTAD hole transport layer

[0117] Preparation method of Spiro-OMeTAD precursor solution: 520 mg of Li-TFSI was dissolved in 1 mL of acetonitrile to obtain a Li-TFSI stock solution; 72.3 mg of Spiro-OMeTAD powder, 28.8 μL of tBP and 17.5 μL of the Li-TFSI stock solution were uniformly mixed in 1 mL of chlorobenzene and stirred at room temperature for 2 h to obtain a Spiro-OMeTAD precursor solution.

[0118] Preparation method of Spiro-OMeTAD hole transport layer: 50 μL of the Spiro-OMeTAD precursor solution was spin-coated uniformly on the surface of the second ammonium salt passivation layer of 8-anilino-1-naphthalenesulfonic acid at 3000 rpm for 20 s, and a Spiro-OMeTAD hole transport layer with a thickness of 150 nm was prepared on the second ammonium salt passivation layer of 8-anilino-1-naphthalenesulfonic acid.

[0119] (7) Preparation of silver electrode

[0120] The device obtained in step (6) was transferred to a vacuum evaporation machine, and a silver electrode with a thickness of 150 nm was deposited on the surface of the Spiro-OMeTAD hole transport layer by using the principle of thermal evaporation, and the evaporation rate was A perovskite solar cell was obtained. Figure 3 This is a schematic diagram of the structure of the perovskite solar cell in Example 1 of the present invention.

[0121] Example 2

[0122] It was basically the same as the preparation method of Example 1, except that in step (3), the concentration of the ammonium salt solution of 8-anilino-1-naphthalenesulfonic acid was 0.05 wt%.

[0123] Example 3

[0124] It was basically the same as the preparation method of Example 1, except that in step (4), the content of the ammonium salt of 8-anilino-1-naphthalenesulfonic acid in the perovskite precursor solution was 2 wt%.

[0125] Example 4

[0126] It is basically the same as the preparation method of Example 1, except that in step (5), the concentration of the 8-anilino-1-naphthalenesulfonic acid ammonium salt solution is 0.3 wt%.

[0127] Example 5

[0128] It is basically the same as the preparation method of Example 1, except that in step (5), the concentration of the 8-anilino-1-naphthalenesulfonic acid ammonium salt solution is 5 wt%.

[0129] Comparative Example 1

[0130] It is basically the same as the preparation method of Example 1, except that 8-anilino-1-naphthalenesulfonic acid ammonium salt is not added to the perovskite precursor solution; an electron transport layer, a perovskite layer without 8-anilino-1-naphthalenesulfonic acid ammonium salt, a hole transport layer and a metal electrode are sequentially stacked on one side of the substrate, and the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer and the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer are not constructed.

[0131] Test Example 1

[0132] Perform performance tests on the conversion efficiency and stability of the perovskite solar cells prepared in Examples 1 to 5 and Comparative Example 1. For each example or comparative example, 3 prepared perovskite solar cells are taken for conversion efficiency testing, and the test results of the 3 perovskite solar cells are averaged to obtain the conversion efficiency of the perovskite solar cells prepared in each example or comparative example; the best-performing cells among the 3 perovskite solar cells in each example or comparative example are taken respectively, and operating tests are carried out under atmospheric environment without any protection measures. The test is stopped when the performance decays to 90% of the original value, and the operating test time of the perovskite solar cells in each example or comparative example is recorded, and this time represents the stability of the perovskite solar cells in each example or comparative example. As shown in Table 2.

[0133] Table 2 Conversion efficiency and stability of perovskite solar cells prepared in Examples 1 to 5 and Comparative Example 1

[0134] Index Conversion efficiency / % Stability / h Example 1 17.02％±0.02 1034 Example 2 16.73％±0.03 1026 Example 3 16.49％±0.04 1021 Example 4 16.01％±0.03 908 Example 5 10.89％±3.21 142 Comparative Example 1 16.94％±0.02 ＜24

[0135] According to Examples 1 to 4 and Comparative Example 1 in Table 2, it can be seen that the stability of the perovskite solar cells prepared by the present invention is significantly higher than that of Comparative Example 1, indicating that the ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, and the ammonium 8 - anilino - 1 - naphthalenesulfonate in the perovskite layer of the perovskite solar cells of the present invention can reduce the erosion of external factors such as oxygen, light, and water vapor on the perovskite solar cells, thereby significantly improving the stability of the perovskite solar cells.

[0136] According to Examples 1 to 4 and Example 5 in Table 2, it can be seen that the conversion efficiency and stability of the perovskite solar cells in Examples 1 to 4 are both higher than those in Example 5; this shows that the content of ammonium 8 - anilino - 1 - naphthalenesulfonate in the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, and the perovskite layer disclosed in the present invention will affect the conversion efficiency and stability of the perovskite solar cells. By controlling the content of ammonium 8 - anilino - 1 - naphthalenesulfonate in the first ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, the second ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer, and the perovskite layer within the scope defined by the present invention, the conversion efficiency and stability of the perovskite solar cells can be improved.

[0137] Figure 1 is the molecular structure diagram of ammonium 8 - anilino - 1 - naphthalenesulfonate; Figure 2 is CH 3 NH 3 PbI 3 is the crystal structure diagram of perovskite. The benzene ring and naphthalene ring in the ammonium 8 - anilino - 1 - naphthalenesulfonate added in the present invention have good hydrophobic ability and chemical inertness, which can block the erosion of moisture and oxygen in the environment on the inside of the perovskite material; the sulfonate group chelates with metal ions, which can improve the stability of the perovskite material; the ammonium group adsorbs on the surface of the perovskite material, ensuring the rapid circulation of photo - generated carriers in the perovskite solar cells.

[0138] Figure 3 is the structural schematic diagram of the perovskite solar cell in Example 1 of the present invention. The present invention adds an ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layer between the electron transport layer and the perovskite layer and between the perovskite layer and the hole transport layer respectively; the ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layers at the two interfaces can serve as a waterproof barrier to protect the middle perovskite layer from the interference of water vapor in the atmosphere, solving the problem of the perovskite solar cell failing in water; moreover, the two ammonium 8 - anilino - 1 - naphthalenesulfonate passivation layers of the present invention together with the ammonium 8 - anilino - 1 - naphthalenesulfonate in the perovskite layer bulk can block the migration of halogen ions or cations inside the perovskite material under the action of light and heat, solving the problem of the perovskite solar cell failing due to ion migration.

[0139] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the spirit of the present invention's design, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A perovskite material, the chemical composition of which includes an organic group, a metal cation, a halogen anion and an ammonium ion; the organic group includes a first organic group and a second organic group; the first organic group is CH3NH3 + or CH3NHNH3 + ; The second organic group is 8-anilino-1-naphthalenesulfonate.

2. The perovskite material according to claim 1, characterized in that: The metal cations include Pb 2+ ; The halogen anions include Cl - Br - or I - .

3. The method for preparing the perovskite material according to claim 1 or 2, comprising the following steps: Mixing a metal halide, an organic halide and an organic solvent to obtain a mixed solution; the organic halide is a compound formed by a first organic group and a halogen; mixing the mixed solution with 8-anilino-1-naphthalenesulfonic acid ammonium salt to obtain a perovskite precursor solution; The perovskite precursor solution is dried to obtain a precursor; and the precursor is annealed to obtain the perovskite material.

4. The method for preparing the perovskite material according to claim 3, characterized in that: The molar ratio of the metal halide to the organic halide is 1:1; the total concentration of the metal halide and the organic halide in the mixed solution is 450-470 mg / mL; the content of 8-anilino-1-naphthalenesulfonic acid ammonium salt in the perovskite precursor solution is 0.05-3 wt %.

5. The method for preparing the perovskite material according to claim 3, characterized in that: The annealing treatment includes a first annealing and a second annealing in sequence; the temperature of the first annealing is 40-60° C., and the insulation time is 25-45 seconds; the temperature of the second annealing is 100-120° C., and the insulation time is 3-10 minutes.

6. A perovskite solar cell, comprising a substrate, an electron transport layer, a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a perovskite layer, a second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a hole transport layer and a metal electrode stacked in sequence; the material of the perovskite layer is the perovskite material according to claim 1 or 2 or the perovskite material prepared by the preparation method according to any one of claims 3 to 5.

7. The perovskite solar cell according to claim 6, characterized in that: The material of the electron transport layer includes SnO2, ZnO, TiO2 or NiO; the material of the metal electrode includes Au or Ag.

8. The perovskite solar cell according to claim 6, characterized in that: The thickness of the electron transport layer is 30 to 80 nm; the thickness of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer is 10 to 15 nm; the thickness of the perovskite layer is 350 to 600 nm; the thickness of the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer is 15 to 20 nm; the thickness of the hole transport layer is 100 to 200 nm; and the thickness of the metal electrode is 140 to 160 nm.

9. The method for preparing a perovskite solar cell according to any one of claims 6 to 8, comprising the following steps: An electron transport layer and a first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer are sequentially stacked on a single side of the substrate; Mixing a metal halide, an organic halide, an organic solvent and 8-anilino-1-naphthalenesulfonic acid ammonium salt to obtain a perovskite precursor solution; coating the perovskite precursor solution on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, and performing an annealing treatment to form a perovskite layer on the surface of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer; A second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer, a hole transport layer and a metal electrode are sequentially constructed on the surface of the perovskite layer to obtain the perovskite solar cell.

10. The method for preparing a perovskite solar cell according to claim 9, characterized in that: The first 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer is formed by a first 8-anilino-1-naphthalenesulfonic acid ammonium salt solution, and the second 8-anilino-1-naphthalenesulfonic acid ammonium salt passivation layer is formed by a second 8-anilino-1-naphthalenesulfonic acid ammonium salt solution; the concentration of the first 8-anilino-1-naphthalenesulfonic acid ammonium salt solution is 0.005-0.1wt%; the concentration of the second 8-anilino-1-naphthalenesulfonic acid ammonium salt solution is 0.05-0.3wt%.

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