Method for increasing the number of layers of two-dimensional perovskite and application thereof

Abstract

The present application relates to the technical field of perovskite solar cells, and mainly relates to a method for increasing the layer number of two-dimensional perovskite and application thereof. A post-processing solution containing PEAI and PEASCN is spin-coated on the surface of a three-dimensional peroviskite to prepare quasi-two-dimensional / three-dimensional peroviskite, a quasi-two-dimensional / three-dimensional mixed peroviskite structure is constructed, and the layer number of the two-dimensional structure on the surface is increased. Compared with the two-dimensional / three-dimensional mixed peroviskite structure, the carrier transport performance is improved. The above method is applied to the preparation of a peroviskite solar cell, the short-circuit current density and the fill factor of the peroviskite solar cell are increased, the efficiency of the transverse structure peroviskite solar cell is increased, and a high-efficiency and stable mixed-dimension transverse structure peroviskite solar cell is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar cells, and particularly relates to a method for increasing the layer number of two-dimensional perovskite and application thereof. BACKGROUND

[0002] Developing low-cost and high-efficiency solar power generation technology is beneficial to achieving the goal of low-carbon social development. Metal halide perovskite solar cells are a new type of photovoltaic technology, which has the characteristics of low preparation cost and high conversion efficiency. The efficiency of the inverse structure (p-i-n) perovskite cell is relatively low, and the highest efficiency is only 23.9%. In recent years, two-dimensional / three-dimensional mixed-dimensional perovskite cells have been widely studied because they have the high efficiency of three-dimensional perovskite and the stability of two-dimensional perovskite. Generally, the preparation of such mixed-dimensional perovskite is achieved by spin-coating a layer of large-size organic cations on the surface of three-dimensional perovskite, and the two-dimensional perovskite is formed on the surface of the three-dimensional perovskite and separates the three-dimensional perovskite from the charge transport layer. The two-dimensional perovskite is composed of a large-size organic cation layer and an inorganic layer, and the effective band gap of the organic layer is much larger than that of the inorganic layer, which acts as an insulating barrier, and the inorganic layer becomes an isolated semiconductor sheet. Therefore, excitons are confined in the two-dimensional inorganic layer, so that the two-dimensional perovskite structure hinders the transmission and collection of electrons. Therefore, increasing the layer number of the inorganic layer in the low-dimensional perovskite can effectively improve the carrier transport capacity. SUMMARY

[0003] The present application aims to provide a method for increasing the layer number of two-dimensional perovskite, and apply it to perovskite solar cells.

[0004] To achieve this goal, the present application adopts the following technical solutions:

[0005] The first aspect of the present application provides a method for increasing the layer number of two-dimensional perovskite, and the specific technical solutions are as follows:

[0006] A method for increasing the layer number of two-dimensional perovskite, a post-processing solution containing PEAI and PEASCN is spin-coated on the surface of three-dimensional perovskite to prepare quasi-two-dimensional / three-dimensional perovskite.

[0007] The stoichiometric molar ratio of PEAI and PEASCN in the post-processing solution containing PEAI and PEASCN in the present application is 1:1.

[0008] The solvent used in the post-processing solution containing PEAI and PEASCN in the present application is isopropyl alcohol.

[0009] The preparation method of the post-processing solution containing PEAI and PEASCN in the present application is to mix PEAI and PEASCN, and stir and dissolve them in an organic solvent.

[0010] The preparation in the application further comprises annealing treatment after spin coating is completed.

[0011] The second aspect of the application provides application of the method for increasing the layer number of two-dimensional perovskite on a perovskite solar cell.

[0012] The third aspect of the application provides a quasi-two-dimensional / three-dimensional perovskite battery device, which comprises, from bottom to top, a conductive substrate, a hole transport layer, a quasi-two-dimensional / three-dimensional perovskite layer, an electron transport layer, an electron blocking layer and a metal electrode layer, wherein the quasi-two-dimensional / three-dimensional perovskite layer is obtained by treating a three-dimensional perovskite thin film by the method for increasing the layer number of two-dimensional perovskite.

[0013] The conductive substrate in the application is any one of an ITO conductive glass substrate and an FTO conductive glass substrate.

[0014] The hole transport layer in the application is any one of NiOx, PTAA and 2PACz.

[0015] The electron transport layer in the application is any one of C60, PCBM and ZnO.

[0016] The electron blocking layer in the application is BCP.

[0017] The metal electrode layer in the application is any one of Ag, Cu and Au.

[0018] The fourth aspect of the application provides a preparation method of the quasi-two-dimensional / three-dimensional perovskite solar cell device, comprising the following steps.

[0019] Step one, assembling a hole transport layer on the surface of a conductive substrate.

[0020] Step two, spin coating a perovskite precursor solution on the surface of the conductive substrate assembled with the hole transport layer, and performing annealing treatment to obtain a three-dimensional perovskite thin film.

[0021] Step three, spin coating a prepared post-treatment solution on the three-dimensional perovskite thin film obtained in step two, and performing annealing treatment to obtain a quasi-two-dimensional / three-dimensional perovskite thin film.

[0022] Step four, preparing an electron transport layer on the quasi-two-dimensional / three-dimensional perovskite thin film obtained in step three.

[0023] Step five, preparing an electron blocking layer on the electron transport layer obtained in step four.

[0024] Step six, preparing a metal electrode on the electron blocking layer obtained in step five to obtain a quasi-two-dimensional / three-dimensional perovskite solar cell device.

[0025] Compared with the prior art, the application has the following beneficial effects:

[0026] The application provides a method for increasing the layer number of two-dimensional perovskite, a post-processing solution is prepared by mixing PEAI and PEASCN, and then a quasi-two-dimensional / three-dimensional hybrid perovskite structure is constructed on the surface of a three-dimensional perovskite by spin coating, so that the layer number of the two-dimensional structure is increased, and the carrier transport performance is improved compared with the two-dimensional / three-dimensional hybrid perovskite structure. The method is applied to the preparation of a perovskite battery, and the short-circuit current density and the fill factor of the perovskite battery are increased, so that the efficiency of the transverse structure perovskite battery is increased, and a high-efficiency and stable hybrid-dimension transverse structure perovskite battery is obtained. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The GIWAXS diagram of the quasi-two-dimensional / three-dimensional hybrid-dimension perovskite film prepared for Example 1 and the two-dimensional / three-dimensional hybrid-dimension perovskite film prepared for Comparative Example 1.

[0028] Figure 2 The GIWAXS diagram of the perovskite film prepared for Comparative Example 2.

[0029] Figure 3 The J-V diagram of the quasi-two-dimensional / three-dimensional hybrid-dimension transverse structure perovskite battery prepared for Example 2 and the two-dimensional / three-dimensional hybrid-dimension transverse structure perovskite battery prepared for Comparative Example 3. DETAILED DESCRIPTION

[0030] The method for increasing the layer number of two-dimensional perovskite and the application thereof to perovskite solar cells are described in detail below.

[0031] Based on the difference in microcrystal structure, metal halide perovskite can be divided into zero-dimensional, one-dimensional, two-dimensional and three-dimensional, etc. Two-dimensional perovskite material has a low-dimensional (layered) structure in which the organic amine layer and the inorganic layer (metal halide crystal) are alternated with each other, and the smaller the number n of octahedral layers separated by the organic amine in the metal halide inorganic layer, the closer the perovskite to the two-dimensional structure. Compared with the traditional three-dimensional perovskite structure, the low-dimensional perovskite material has two great advantages when applied to photovoltaic devices: (1) the moisture resistance and photothermal stability are greatly enhanced; (2) the optical and electrical properties can be adjusted by changing n and the type of inserted organic amine. However, the low-dimensional perovskite has a large optical band gap, and the introduction of organic amine reduces the carrier mobility, resulting in that the efficiency of the low-dimensional perovskite battery is significantly lower than that of the three-dimensional perovskite battery.

[0032] The first aspect of the application provides a method for increasing the layer number of two-dimensional perovskite, a post-processing solution containing PEAI and PEASCN is spin-coated on the surface of a three-dimensional perovskite to prepare a quasi-two-dimensional / three-dimensional perovskite.

[0033] The quasi-two-dimensional perovskite adopts a large-volume organic component to greatly replace a small-molecule organic component, destroys the original three-dimensional framework, forms a stable quasi-two-dimensional framework, and the inorganic layer number of the quasi-two-dimensional perovskite is greater than or equal to 2, which has a better energy level matching with the three-dimensional perovskite and is beneficial to the transport of carriers. Phenylethylamine hydroiodide, abbreviated as PEAI, the two-dimensional perovskite formed on the surface of the three-dimensional perovskite by using a post-processing solution of PEAI can passivate surface defects, and the hydrophobic benzene ring on the cation of PEAI can play a role in isolating water vapor, thereby greatly improving the photoelectric conversion efficiency and stability of the perovskite solar cell; phenylethylamine thiocyanate, abbreviated as PEASCN, a post-processing solution of PEASCN cannot form a two-dimensional or quasi-two-dimensional perovskite when spin-coated on the surface of the three-dimensional perovskite. The method provided in the application adopts a post-processing solution containing PEAI and PEASCN to be spin-coated on the surface of the three-dimensional perovskite, and a quasi-two-dimensional / three-dimensional perovskite is prepared.

[0034] The stoichiometric molar ratio of PEAI to PEASCN in the post-processing solution containing PEAI and PEASCN is 1:1.

[0035] The solvent used in the post-processing solution containing PEAI and PEASCN is isopropyl alcohol.

[0036] The preparation method of the post-processing solution containing PEAI and PEASCN is to mix PEAI and PEASCN, and stir and dissolve them in an organic solvent.

[0037] The preparation further includes an annealing treatment after spin coating.

[0038] The second aspect of the application provides an application of the method for increasing the layer number of the two-dimensional perovskite to a perovskite solar cell.

[0039] The third aspect of the application provides a quasi-two-dimensional / three-dimensional perovskite solar cell device, which comprises, from bottom to top, a conductive substrate, a hole transport layer, a quasi-two-dimensional / three-dimensional perovskite layer, an electron transport layer, an electron blocking layer and a metal electrode layer, and the quasi-two-dimensional / three-dimensional perovskite layer is obtained by treating a three-dimensional perovskite thin film by using the method for increasing the layer number of the two-dimensional perovskite.

[0040] The conductive substrate is any one of an ITO conductive glass substrate and an FTO conductive glass substrate.

[0041] The hole transport layer is any one of NiO X , PTAA and 2PACz. In some embodiments of the application, the hole transport layer is NiO.

[0042] The electron transport layer is C 60, PCBM or ZnO. In some embodiments of the present application, the electron transport layer is C 60 , preferably 23 nm.

[0043] In the present application, the electron blocking layer is BCP. In some embodiments of the present application, the electron blocking layer is BCP, and the thickness of the BCP is 5-10 nm, preferably 8 nm.

[0044] In the present application, the metal electrode layer is any one of Ag, Cu, and Au. In some embodiments of the present application, the metal electrode layer is Ag, and the thickness of the Ag is 100-150 nm, preferably 100 nm.

[0045] The fourth aspect of the present application provides a method for preparing the quasi-two-dimensional / three-dimensional perovskite solar cell device, comprising the following steps:

[0046] Step one: assembling a hole transport layer on the surface of a conductive substrate;

[0047] Step two: spin-coating a perovskite precursor solution on the surface of the conductive substrate assembled with the hole transport layer, and performing annealing treatment to obtain a three-dimensional perovskite film;

[0048] Step three: spin-coating a prepared post-treatment solution on the three-dimensional perovskite film obtained in step two, and performing annealing treatment to obtain a quasi-two-dimensional / three-dimensional perovskite film;

[0049] Step four: preparing an electron transport layer on the quasi-two-dimensional / three-dimensional perovskite film obtained in step three;

[0050] Step five: preparing an electron blocking layer on the electron transport layer obtained in step four;

[0051] Step six: preparing a metal electrode on the electron blocking layer obtained in step five to obtain a quasi-two-dimensional / three-dimensional perovskite solar cell device.

[0052] In some embodiments of the present application, the conductive substrate is an ITO conductive glass substrate, and before use, the ITO conductive glass substrate needs to be cleaned, specifically: the ITO conductive glass substrate is ultrasonically cleaned with a glass cleaner, deionized water, and isopropyl alcohol, respectively, and after drying, the surface of the ITO conductive glass substrate is treated with a UV ozone machine for 15-30 min, preferably 20 min.

[0053] In some embodiments of the present application, the method for assembling the hole transport layer in step one is: spin-coating a hole transport layer material on the surface of the conductive substrate; the hole transport layer material is NiO xThe solution, in which the solvent is any one of benzene, chloroform and n-hexane; the specific operation of spin coating is to drop 50-70 μL of hole transport layer material onto a clean conductive substrate surface, rotate at 3000-6000 rpm for 30-60 seconds, and then quickly transfer it to a nitrogen glove box after spin coating is completed.

[0054] In some embodiments of the present invention, the perovskite precursor solution in step two is prepared by weighing PbI2, PbBr2, CsI, and FAI according to the stoichiometric ratio, dissolving them in a polar solvent, and stirring. In some preferred embodiments of the present invention, the stoichiometric molar ratio of PbI2, PbBr2, CsI, and FAI is 2:3:1:4; the polar solvent is a DMF / DMSO mixed solvent with a volume ratio of 3:1.

[0055] In some embodiments of the present invention, the specific operation of spin-coating the perovskite precursor solution onto the surface of the conductive substrate with the hole transport layer assembled in step two is as follows: 50-70 μL of the perovskite precursor solution is dropped onto the surface of the conductive substrate with the hole transport layer assembled, and the substrate is rotated at 1000-3000 rpm for 10-20 s, then at 3000-8000 rpm for 15-30 s. Anisole, the antisolvent, is added dropwise at the 5th-15th second before the end of spin-coating. Preferably, the rotation is 1000 rpm for 10 s, then 5000 rpm for 15 s, and anisole, the antisolvent, is added dropwise at the 5th second before the end of spin-coating; further, the volume of the antisolvent is 100-300 μL.

[0056] The annealing process described in step two involves annealing on a hot plate at 90–150°C for 10–30 minutes; preferably, annealing on a hot plate at 100°C for 10 minutes.

[0057] The stoichiometric molar ratio of PEAI and PEASCN in the post-treatment solution described in step three is 1:1.

[0058] The specific operation of spin-coating the post-treatment solution in step three onto the three-dimensional perovskite film obtained in step two is as follows: take 60-100 μL of the post-treatment solution and drop it onto the three-dimensional perovskite film, and rotate at 3000-8000 rpm for 20-60 seconds.

[0059] The annealing process described in step three involves annealing on a hot plate at 90–150°C for 5–30 minutes; preferably, annealing on a hot plate at 100°C for 10 minutes.

[0060] In step four, the electron transport layer is C. 60 The preparation method is vapor deposition.

[0061] In step five, the electron blocking layer is a BCP, and the preparation method is vapor deposition.

[0062] In step six, the metal electrode is Ag, and the preparation method is vapor deposition.

[0063] The following detailed description of specific embodiments of the present invention, in conjunction with preferred embodiments, further illustrates the relevant details. When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range, as well as any value between the two endpoints, may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by those skilled in the art. In addition to the specific methods, devices, and materials used in the embodiments, the present invention can be implemented using any prior art methods, devices, and materials similar to or equivalent to those described in the embodiments of the present invention, provided that those skilled in the art possess the prior art and the description of the present invention.

[0064] Example 1: Preparation of Quasi-Two-Dimensional / Three-Dimensional Perovskite Thin Films

[0065] (1) Preparation of post-treatment solution: Weigh equal amounts of PEAI and PEASCN into a glass bottle, stir and dissolve in isopropanol to prepare a post-treatment solution with a concentration of 1 mg / mL.

[0066] (2) Preparation of perovskite precursor solution: Weigh PbI2, PbBr2, CsI, FAI and other reagents into a glass bottle according to the stoichiometric molar ratio of 0.4:0.6:0.2:0.8, dissolve them in a DMF / DMSO mixed solvent with a volume ratio of 3:1, and the concentration is 1.2 mol / L. Stir to obtain perovskite precursor solution.

[0067] (3) ITO glass cleaning: ITO conductive glass was ultrasonically cleaned with glass cleaner, deionized water and isopropanol respectively. After drying, the ITO surface was treated with ultraviolet ozone generator for 20 minutes.

[0068] (4) Hole transport layer preparation: Nickel oxide hole transport layer with a concentration of 20 mg / ml was spin-coated on ITO conductive glass. 50 μL was added dropwise, and the mixture was rotated at 3000 rpm for 30 s. Then it was quickly transferred to a nitrogen glove box.

[0069] (5) Preparation of three-dimensional perovskite active layer: 60 μL of the prepared perovskite precursor solution was added and spin-coated onto ITO conductive glass with hole transport layer, and annealed at 100°C for 10 min to obtain three-dimensional perovskite film.

[0070] (6) Preparation of quasi-two-dimensional perovskite layer: 60 μL of the prepared post-treatment dissolution was added and spin-coated onto the above three-dimensional perovskite film, and annealed at 100°C for 10 min to obtain quasi-two-dimensional / three-dimensional perovskite film.

[0071] The quasi-two-dimensional / three-dimensional perovskite thin film samples obtained in Example 1 were characterized by grazing incidence wide-angle / small-angle X-ray scattering (GIWAXS / GISAXS), and the results are as follows: Figure 1 As shown in (a), the low-dimensional structure of the thin film is a pure quasi-two-dimensional perovskite structure, without any two-dimensional structure.

[0072] Example 2: Fabrication of inverse-structure quasi-two-dimensional / three-dimensional perovskite solar cell devices

[0073] (1) Preparation of post-treatment solution: Weigh equal amounts of PEAI and PEASCN into a glass bottle, stir and dissolve in isopropanol to prepare a post-treatment solution with a concentration of 1 mg / mL.

[0074] (2) Preparation of perovskite precursor solution: Weigh PbI2, PbBr2, CsI, FAI and other reagents into a glass bottle according to the stoichiometric molar ratio of 0.4:0.6:0.2:0.8, dissolve them in a DMF / DMSO mixed solvent with a volume ratio of 3:1, and the concentration is 1.2 mol / L. Stir to obtain perovskite precursor solution.

[0075] (3) ITO glass cleaning: ITO conductive glass was ultrasonically cleaned with glass cleaner, deionized water and isopropanol respectively. After drying, the ITO surface was treated with ultraviolet ozone generator for 20 minutes.

[0076] (4) Hole transport layer preparation: Nickel oxide hole transport layer with a concentration of 20 mg / ml was spin-coated on ITO conductive glass. 50 μL was added dropwise, and the mixture was rotated at 3000 rpm for 30 s. Then it was quickly transferred to a nitrogen glove box.

[0077] (5) Preparation of three-dimensional perovskite active layer: 60 μL of the prepared perovskite precursor solution was added and spin-coated onto ITO conductive glass with hole transport layer, and annealed at 100°C for 10 min to obtain three-dimensional perovskite film.

[0078] (6) Preparation of quasi-two-dimensional perovskite layer: 60 μL of the prepared post-treatment dissolution was added and spin-coated onto the above three-dimensional perovskite film, and annealed at 100°C for 10 min to obtain quasi-two-dimensional / three-dimensional perovskite film.

[0079] (7) A 23 nm electron transport layer C is deposited on the quasi-two-dimensional / three-dimensional perovskite thin film obtained in step (6). 60 .

[0080] (8) An 8 nm electron blocking layer BCP is deposited on the above effective layer.

[0081] (9) A 100 nm metal electrode Ag is deposited on the above effective layer to obtain a reverse structure quasi-two-dimensional / three-dimensional perovskite solar cell device.

[0082] The performance of the inverted quasi-two-dimensional / three-dimensional perovskite solar cell device prepared in Example 2 was tested, such as... Figure 3 As shown in (a), at 100 mW / cm 2 The photoelectric conversion efficiency of the perovskite solar cell sample was tested under standard light intensity irradiation. Its open-circuit voltage was 1.29 V, and its short-circuit current density was 18.04 mA / cm². 2 The fill factor is 79.17%, and the efficiency is 18.35%.

[0083] Comparative Example 1: Preparation of Two-Dimensional / Three-Dimensional Perovskite Thin Films

[0084] (1) Preparation of post-treatment solution: Weigh PEAI into a glass bottle, stir and dissolve it in isopropanol to prepare a post-treatment solution with a concentration of 1 mg / mL.

[0085] (2) Preparation of perovskite precursor solution: Weigh PbI2, PbBr2, CsI, FAI and other reagents into a glass bottle according to the stoichiometric molar ratio of 0.4:0.6:0.2:0.8, dissolve them in a DMF / DMSO mixed solvent with a volume ratio of 3:1, and the concentration is 1.2 mol / L. Stir to obtain perovskite precursor solution.

[0086] (3) ITO glass cleaning: ITO conductive glass was ultrasonically cleaned with glass cleaner, deionized water and isopropanol respectively. After drying, the ITO surface was treated with ultraviolet ozone generator for 20 minutes.

[0087] (4) Hole transport layer preparation: Nickel oxide hole transport layer with a concentration of 20 mg / mL was spin-coated on ITO conductive glass. 50 μL was added dropwise, and the mixture was rotated at 3000 rpm for 30 s. Then it was quickly transferred to a nitrogen glove box.

[0088] (5) Preparation of three-dimensional perovskite active layer: 60 μL of the prepared perovskite precursor solution was added and spin-coated onto ITO conductive glass with hole transport layer, and annealed at 100°C for 10 min to obtain three-dimensional perovskite film.

[0089] (6) Preparation of two-dimensional perovskite layer: 60 μL of the prepared post-treatment dissolution was added and spin-coated onto the above three-dimensional perovskite film, and annealed at 100 °C for 10 min to obtain two-dimensional / three-dimensional perovskite film.

[0090] The two-dimensional / three-dimensional perovskite thin film samples obtained in Comparative Example 1 were characterized by grazing incidence wide-angle / small-angle X-ray scattering (GIWAXS / GISAXS), such as... Figure 1 As shown in (b), the low-dimensional structure generated in the film is a two-dimensional structure. Comparative Example 2: Preparation of perovskite thin films using PEASCN post-treatment solution.

[0091] (1) Preparation of post-treatment solution: Weigh PEASCN into a glass bottle, stir and dissolve it in isopropanol to prepare a post-treatment solution with a concentration of 1 mg / mL.

[0092] (2) Preparation of perovskite precursor solution: Weigh PbI2, PbBr2, CsI, FAI and other reagents into a glass bottle according to the stoichiometric molar ratio of 0.4:0.6:0.2:0.8, dissolve them in a DMF / DMSO mixed solvent with a volume ratio of 3:1, and the concentration is 1.2 mol / L. Stir to obtain perovskite precursor solution.

[0093] (3) ITO glass cleaning: ITO conductive glass was ultrasonically cleaned with glass cleaner, deionized water and isopropanol respectively. After drying, the ITO surface was treated with ultraviolet ozone generator for 20 minutes.

[0094] (4) Hole transport layer preparation: Nickel oxide hole transport layer with a concentration of 20 mg / mL was spin-coated on ITO conductive glass. 50 μL was added dropwise, and the mixture was rotated at 3000 rpm for 30 s. Then it was quickly transferred to a nitrogen glove box.

[0095] (5) Preparation of three-dimensional perovskite active layer: 60 μL of the prepared perovskite precursor solution was added and spin-coated onto ITO conductive glass with hole transport layer, and annealed at 100°C for 10 min to obtain three-dimensional perovskite film.

[0096] (6) Post-treatment of PEASCN solution: 60 μL of the prepared PEASCN solution was added dropwise and spin-coated onto the above three-dimensional perovskite film. The film was then annealed at 100 °C for 10 min to obtain the PEASCN post-treated perovskite film.

[0097] The PEASCN-treated perovskite film samples obtained in Comparative Example 2 were characterized by grazing incidence wide-angle / small-angle X-ray scattering (GIWAXS / GISAXS), such as... Figure 2 As shown, no low-dimensional structures were found on the surface of the thin film.

[0098] Comparative Example 3: Fabrication of two-dimensional / three-dimensional perovskite solar cell devices with inverse structure hybrid dimensions

[0099] (1) Preparation of post-treatment solution: Weigh PEAI into a glass bottle, stir and dissolve it in isopropanol to prepare a post-treatment solution with a concentration of 1 mg / mL.

[0100] (2) Preparation of perovskite precursor solution: Weigh PbI2, PbBr2, CsI, FAI and other reagents into a glass bottle according to the stoichiometric molar ratio of 0.4:0.6:0.2:0.8, dissolve them in a DMF / DMSO mixed solvent with a volume ratio of 3:1, and the concentration is 1.2 mol / L. Stir to obtain perovskite precursor solution.

[0101] (3) ITO glass cleaning: ITO conductive glass was ultrasonically cleaned with glass cleaner, deionized water and isopropanol respectively. After drying, the ITO surface was treated with ultraviolet ozone generator for 20 minutes.

[0102] (4) Hole transport layer preparation: Nickel oxide hole transport layer with a concentration of 20 mg / mL was spin-coated on ITO conductive glass. 50 μL was added dropwise, and the mixture was rotated at 3000 rpm for 30 s. Then it was quickly transferred to a nitrogen glove box.

[0103] (5) Preparation of three-dimensional perovskite active layer: 60 μL of the prepared perovskite precursor solution was added and spin-coated onto ITO conductive glass with hole transport layer, and annealed at 100°C for 10 min to obtain three-dimensional perovskite film.

[0104] (6) Preparation of two-dimensional perovskite layer: 60 μL of the prepared post-treatment dissolution was added and spin-coated onto the above three-dimensional perovskite film, and annealed at 100 °C for 10 min to obtain two-dimensional / three-dimensional perovskite film.

[0105] (7) A 23 nm electron transport layer C is deposited on the two-dimensional / three-dimensional perovskite thin film obtained in step (6). 60 .

[0106] (8) An 8 nm electron blocking layer BCP is deposited on the above effective layer.

[0107] (9) A 100 nm metal electrode Ag is deposited on the above effective layer to obtain a two-dimensional / three-dimensional perovskite solar cell device with an inverse structure.

[0108] Performance tests were conducted on the inverse-structure hybrid two-dimensional / three-dimensional perovskite solar cell device prepared in Comparative Example 3, such as... Figure 3 As shown in (b), at 100mW / cm 2 The photoelectric conversion efficiency of the perovskite solar cell sample was tested under standard light intensity irradiation. Its open-circuit voltage was 1.30V and its short-circuit current density was 17.76mA / cm². 2 The fill factor is 75.10%, and the efficiency is 17.34%.

[0109] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for increasing the number of layers in a two-dimensional perovskite, characterized in that, Quasi-two-dimensional / three-dimensional perovskites were prepared by spin-coating a post-treatment solution containing PEAI and PEASCN onto the surface of a three-dimensional perovskite; the number of inorganic layers in the quasi-two-dimensional perovskite was greater than or equal to 2.

2. The method for increasing the number of layers in a two-dimensional perovskite as described in claim 1, characterized in that, It also includes one or more of the following features: (1) The stoichiometric molar ratio of PEAI and PEASCN in the post-treatment solution containing PEAI and PEASCN is 1:

1. (2) The solvent used in the post-treatment solution containing PEAI and PEASCN is isopropanol; (3) The method for preparing the post-treatment solution containing PEAI and PEASCN is to mix PEAI and PEASCN and stir to dissolve them in an organic solvent. (4) The preparation also includes annealing after spin coating.

3. The method for increasing the number of layers in a two-dimensional perovskite as described in claim 1 or 2, applied to perovskite solar cells.

4. A quasi-two-dimensional / three-dimensional perovskite solar cell device, comprising, from bottom to top, a conductive substrate, a hole transport layer, a quasi-two-dimensional / three-dimensional perovskite layer, an electron transport layer, an electron blocking layer, and a metal electrode layer, wherein the quasi-two-dimensional / three-dimensional perovskite layer is obtained by processing a three-dimensional perovskite thin film using the method described in claim 1 for increasing the number of layers in a two-dimensional perovskite.

5. The quasi-two-dimensional / three-dimensional perovskite solar cell device as described in claim 4, characterized in that, Includes one or more of the following characteristics: 1) The conductive substrate is either an ITO conductive glass substrate or an FTO conductive glass substrate; 2) The hole transport layer is NiO. x Any one of PTAA, 2PACz; 3) The electron transport layer is C 60 Any one of PCBM and ZnO; 4) The electron blocking layer is a BCP; 5) The metal electrode layer is any one of Ag, Cu, and Au.

6. The quasi-two-dimensional / three-dimensional perovskite solar cell device as described in claim 5, characterized in that, It also includes one or more of the following features: 3a) The electron transport layer is C 60 Its thickness is 20–30 nm; 4a) The electron blocking layer is a BCP with a thickness of 5-10 nm; 5a) The metal electrode layer is Ag, and its thickness is 100-150 nm.

7. The method for fabricating a quasi-two-dimensional / three-dimensional perovskite solar cell device as described in any one of claims 4 to 6, characterized in that, Includes the following steps: Step 1: Assemble a hole transport layer on the surface of a conductive substrate; Step 2: Spin-coat the perovskite precursor solution onto the surface of a conductive substrate with a hole transport layer assembled, and anneal it to obtain a three-dimensional perovskite film. Step 3: Spin-coat the prepared post-treatment solution onto the three-dimensional perovskite film obtained in Step 2, and anneal it to obtain a quasi-two-dimensional / three-dimensional perovskite film. Step 4: Prepare an electron transport layer on the quasi-two-dimensional / three-dimensional perovskite thin film obtained in Step 3; Step 5: Prepare an electron blocking layer on the electron transport layer obtained in Step 4; Step 6: Fabricate metal electrodes on the electron blocking layer obtained in Step 5 to obtain a quasi-two-dimensional / three-dimensional perovskite solar cell device with mixed dimensions.

8. The method for fabricating a quasi-two-dimensional / three-dimensional perovskite solar cell device as described in claim 7, characterized in that, It also includes one or more of the following features: (i) The method for assembling the conductive substrate of the hole transport layer in step one is to spin-coat the hole transport layer material onto the surface of the conductive substrate. (ii) The perovskite precursor solution described in step two is prepared by weighing PbI2, PbBr2, CsI, and FAI according to the stoichiometric ratio, dissolving them in a polar solvent, and stirring. (iii) The specific operation of spin-coating the perovskite precursor solution on the surface of the conductive substrate with the hole transport layer in step two is as follows: take 50-100 μL of perovskite precursor solution and drop it onto the surface of the conductive substrate with the hole transport layer, rotate at 1000-3000 rpm for 10-20 s, rotate at 3000-8000 rpm for 15-30 s, and add the anti-solvent anisole in the 5th to 15th s before the end of spin-coating; (iv) The annealing process described in step two is annealing on a hot plate at 90-150°C for 10-30 minutes; (v) The stoichiometric molar ratio of PEAI and PEASCN in the post-treatment solution described in step three is 1:1; (vi) The specific operation of spin-coating the post-treatment solution in step three onto the three-dimensional perovskite film obtained in step two is as follows: take 60-100 μL of the post-treatment solution and drop it onto the three-dimensional perovskite film, and rotate at 3000-8000 rpm for 30-60 seconds. (vii) The annealing process described in step three is annealing on a hot plate at 90-150°C for 5-30 minutes; (ⅷ) In step four, the electron transport layer is C. 60 The preparation method is vapor deposition; (ⅸ) The electron blocking layer in step five is BCP, and the preparation method is vapor deposition; (x) In step six, the metal electrode is Ag, and the preparation method is vapor deposition.

9. The method for fabricating a quasi-two-dimensional / three-dimensional perovskite solar cell device as described in claim 8, characterized in that, The feature (i) also includes one or more of the following features: (i) The hole transport layer material is NiO with a concentration of 10-40 mg / mL. x The solution is a solvent selected from benzene, chloroform, and n-hexane. (ii) The specific operation of spin coating is to take 50-70 μL of hole transport layer material and drop it onto a clean conductive substrate surface, and rotate at 3000-6000 rpm for 30-60 seconds. (iii) After the spin coating is completed, the conductive substrate is quickly transferred to a nitrogen glove box.

10. The method for fabricating a quasi-two-dimensional / three-dimensional perovskite solar cell device as described in claim 8, characterized in that, The feature (ii) also includes one or more of the following features: (a) The stoichiometric molar ratio of PbI2, PbBr2, CsI, and FAI is 2:3:1:4; (b) The polar solvent is a DMF / DMSO mixture with a volume ratio of 3:1.

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