A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution and its preparation method and application

Abstract

The present invention discloses a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution and its preparation method and application. The perovskite precursor solution includes phenethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide, magnesium acetate and solvent; the molar ratio of phenethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide and magnesium acetate is 0.1:0.675:0.225:1:(0.05-0.15). 0.1 (FA 0.75 MA 0.25 ) 0.9 Adding a specific proportion of magnesium acetate to the SnI3 perovskite precursor solution significantly enhances the oxidation resistance and thermal stability of the perovskite precursor solution, reduces the deep defect states of the perovskite film prepared therefrom, and can significantly increase the open circuit voltage of the perovskite solar cell prepared containing the perovskite film, improve its photoelectric performance, and can be applied in the optoelectronic field.

Description

Technical Field

[0001] The present invention relates to the technical field of perovskite solar cell devices, and more specifically, to a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, preparation method and application thereof. Background Art

[0002] Lead (Pb)-based perovskite solar cells have seen rapid development in recent years, but potential environmental pollution has hindered their commercial application. Consequently, efforts are underway to identify environmentally friendly, lead-free or low-lead perovskite materials. In this context, tin (Sn)-based perovskites are considered one of the most promising alternatives to lead-based perovskites due to their low environmental and biological toxicity, low exciton binding energy, and narrow optical band gap. Currently, they have shown promising application prospects in perovskite solar cells and perovskite light-emitting devices.

[0003] PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 is a two-dimensional tin (Sn)-based perovskite material with excellent photoelectric properties and better stability than traditional three-dimensional tin (Sn)-based perovskite materials (such as FASnI3). Its film can be prepared by spin coating, scraping, printing, etc. 0.1 (FA 0.75 MA 0.25 ) 0.9 The stability of SnI3 two-dimensional perovskite materials is improved compared with three-dimensional materials, but the Sn in the perovskite precursor solution is 2+ Still easily oxidized to Sn 4+ , which leads to the degradation of the precursor solution and reduces the quality of the perovskite film prepared on its basis, thereby affecting the photoelectric performance of the prepared perovskite solar cell.

[0004] The existing technology adds potassium acetate to the tin-based perovskite precursor solution to inhibit Sn 2+ The potassium ion perovskite lattice fills the cell gaps through oxidation. By expanding the cell, the prepared perovskite film has better crystallinity and reduces the defect density, but most of the defects reduced are surface defects, and the open circuit voltage of the perovskite solar cell is not effectively improved.

[0005] Therefore, how to effectively solve PEA 0.1 (FA 0.75 MA 0.25 )0.9 Sn in SnI3 perovskite 2+ The problem of simultaneously oxidizing and improving the photoelectric performance of perovskite solar cells is a research focus and difficulty in the field of tin-based perovskite materials. Summary of the Invention

[0006] One purpose of the present invention is to solve the problem of PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Sn in SnI3 perovskite 2+ Oxidation and improvement of the photoelectric performance of perovskite solar cells, providing a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, the anti-oxidation time of the perovskite precursor solution is greatly extended and the thermal stability is also enhanced.

[0007] The second object of the present invention is to provide a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

[0008] The third object of the present invention is to provide a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cells.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, including phenylethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide, magnesium acetate and solvent;

[0011] The molar ratio of the phenethylammonium iodide, iodomethane, iodine methylamine, stannous iodide and magnesium acetate is 0.1:0.675:0.225:1:(0.05-0.15).

[0012] The present invention is in PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 A specific proportion of magnesium acetate is added to the SnI3 perovskite precursor solution. On the one hand, the acetate ions in magnesium acetate can play a good antioxidant role. 2+Combined to form a protective layer, it provides antioxidant protection for the precursor solution and can protect PEA for a long time. 0.1 (FA 0.75 MA 0.25 ) 0.9 Sn in SnI3 perovskite precursor solution 2+ It is not oxidized in large quantities, the anti-oxidation time is significantly prolonged, and the thermal stability is also enhanced; on the other hand, the magnesium ions in magnesium acetate enter the perovskite unit cell to replace part of the Sn 2+ The position of the perovskite film can be reduced, which can reduce the deep defect states of the perovskite film prepared in this way, significantly improve the open circuit voltage of the perovskite solar cell prepared with this perovskite film, improve its photoelectric performance, and have good application prospects in the optoelectronic field.

[0013] At the same time, the present invention has found through experiments that when the content of magnesium acetate is too low, PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The oxidation resistance and thermal stability of SnI3 perovskite precursor solution cannot be effectively improved; if the content of magnesium acetate is too high, the prepared PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The quality of SnI3 perovskite film is adversely affected.

[0014] Preferably, the molar ratio of phenethylammonium iodide, iodomethane, iodine methylamine, stannous iodide, and magnesium acetate is 0.1:0.675:0.225:1:0.1.

[0015] Furthermore, the solvent is dimethyl sulfoxide and / or dimethylformamide.

[0016] Furthermore, the solvent is a mixed solvent consisting of dimethyl sulfoxide and dimethylformamide, and the volume ratio of dimethyl sulfoxide to dimethylformamide in the mixed solvent is 1:4.

[0017] The present invention also provides a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The method for preparing SnI3 perovskite precursor solution comprises the following steps:

[0018] Phenethylammonium iodide (PEAI), iodomethane (FAI), iodomethane (MAI) and stannous iodide (SnI2) are added to a solvent to obtain a mixed solution, magnesium acetate or its solution is added to the mixed solution, and the PEA is obtained after mixing evenly. 0.1 (FA 0.75 MA0.25 ) 0.9 The SnI3 perovskite precursor solution comprises phenylethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide and magnesium acetate in a molar ratio of 0.1:0.675:0.225:1:(0.05-0.15).

[0019] In this PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Preparation of SnI3 perovskite precursor solution, preparation of PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution can be prepared by first adding phenylethylammonium iodide (PEAI), iodomethane (FAI), iodomethane (MAI) and stannous iodide (SnI2) into a mixed solvent of dimethyl sulfoxide and dimethylformamide to obtain a mixed solution, and then adding magnesium acetate to the mixed solution and mixing them evenly to obtain the PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution; Alternatively, phenylethylamine iodide (PEAI), iodomethane (FAI), iodomethane (MAI) and stannous iodide (SnI2) may be added to dimethylformamide to obtain a mixed solution, magnesium acetate may be added to dimethyl sulfoxide and mixed evenly, and then added to the mixed solution, and mixed evenly again to obtain the PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution; Alternatively, phenylethylammonium iodide (PEAI), iodomethane (FAI), iodomethane (MAI) and stannous iodide (SnI2) may be added to dimethyl sulfoxide to obtain a mixed solution, magnesium acetate may be added to dimethylformamide and mixed evenly, and then added to the mixed solution, and mixed evenly again to obtain the PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution.

[0020] Furthermore, the solvent is dimethyl sulfoxide (DMSO) and / or dimethylformamide (DMF).

[0021] Furthermore, the solvent is a mixed solvent consisting of dimethyl sulfoxide and dimethylformamide, and the volume ratio of dimethyl sulfoxide to dimethylformamide in the mixed solvent is 1:4.

[0022] A PEA 0.1 (FA 0.75MA 0.25 ) 0.9 SnI3 perovskite film is prepared by the following method:

[0023] The above-mentioned PEA of the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was spin-coated on the substrate for 30 to 60 seconds, and the anti-solvent was added 10 to 20 seconds after the start of spin coating. 0.1 (FA 0.75 MA 0.25 ) 0.9 The substrate of SnI3 perovskite precursor solution is annealed to obtain PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

[0024] The acetate ion and PEA of the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 Sn in SnI3 perovskite precursor solution 2+ Combined to form a protective layer to prevent Sn 2+ Oxidation improves the crystallinity of the film, and magnesium ions can enter the perovskite unit cell and replace part of Sn 2+ position, shrinking the unit cell and increasing the defect formation energy of the perovskite film. This reduces the defects inside the perovskite film during the film formation process and improves the overall photoelectric performance of the film. The prepared PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The crystallinity of SnI3 perovskite film is enhanced, the overall density is effectively improved, the damage of oxygen and water to the perovskite film is reduced, and excellent quality PEA is prepared. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

[0025] Furthermore, the substrate is an ITO (Indium Tin Oxide) glass substrate.

[0026] Furthermore, the spin coating is performed at a rotation speed of 4000 to 5000 rpm.

[0027] Furthermore, the annealing treatment is performed on a hot plate at 100-120° C. for 10-12 minutes.

[0028] Furthermore, the anti-solvent is one of chlorobenzene, toluene, ethyl acetate, ethyl ether, dichloromethane, and anisole.

[0029] The present invention provides PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Application of SnI3 perovskite thin films in the optoelectronic field.

[0030] The present invention provides the above-mentioned PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Application of SnI3 perovskite thin films in the optoelectronic field.

[0031] Furthermore, the broadcasting and television field includes solar cells, photodetectors, light-emitting devices and other fields.

[0032] The present invention provides a PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cell, comprising the PEA prepared by the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

[0033] PEA of the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite film is formed due to the magnesium ions entering the perovskite unit cell and replacing part of the Sn 2+ The position of the unit cell shrinks, the deep defect state of the perovskite film is reduced, which is beneficial to improve the PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Open-circuit voltage of SnI3 perovskite solar cells, thereby improving PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Photovoltaic performance of SnI3 perovskite solar cells.

[0034] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cells are prepared by the following method:

[0035] P1. Sequentially use acetone, ethanol, and deionized water to clean the ITO glass substrate, dry it at high temperature, and spin-coat the hole transport material on the treated ITO glass substrate;

[0036] P2. Preparation of PEA on an ITO glass substrate spin-coated with hole transport material 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film;

[0037] P3. PEA obtained in P2 0.1 (FA 0.75 MA 0.25 ) 0.9 Electron transport materials, interface modification materials and metal electrodes were vacuum evaporated onto SnI3 perovskite films.

[0038] The present invention also protects the above-mentioned PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Application of SnI3 perovskite solar cells in the photovoltaic field.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) PEA of the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution contains a certain proportion of magnesium acetate. The acetate ions in magnesium acetate can react with Sn 2+ Combined to form a protective layer, it can protect the Sn in the perovskite precursor solution for a long time 2+ It is not oxidized in large quantities, and the anti-oxidation time is significantly extended. At the same time, the thermal stability is also enhanced.

[0041] (2) The magnesium ions of magnesium acetate in the perovskite precursor solution of the present invention can enter the perovskite unit cell and replace part of the Sn 2+ position, causing the unit cell to shrink; at the same time, it can improve the defect formation energy of the perovskite film, reduce the defects inside the perovskite film during the film formation process, and improve the overall photoelectric performance of the film. 0.1 (FA 0.75 MA 0.25 ) 0.9 The crystallinity of SnI3 perovskite film is enhanced, the overall density is effectively improved, and the damage of oxygen and water to the perovskite film is reduced; PEA prepared with this perovskite film 0.1 (FA 0.75 MA 0.25 )0.9 The open circuit voltage of SnI3 perovskite solar cells is significantly improved, thereby improving PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The photoelectric properties of SnI3 perovskite solar cells can be applied to photovoltaic fields such as solar cells, photodetectors, and light-emitting devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 PEA of Example 1 and Comparative Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 Oxidation test results of SnI3 perovskite precursor solution exposed to air;

[0043] Figure 1 (a) and (b) are PEA of Comparative Example 1. 0.1 (FA 0.75 MA 0.25 ) 0.9 Sample photos of SnI3 perovskite precursor solution at the initial stage and after exposure to air for 10 minutes, (c) and (d) are PEA of Example 1 respectively. 0.1 (FA 0.75 MA 0.25 ) 0.9 Photos of SnI3 perovskite precursor solution and the sample after exposure to air for 10 minutes.

[0044] Figure 2 PEA of Example 1 and Comparative Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 Comparison chart of thermal stability aging test of SnI3 perovskite precursor solution;

[0045] Figure 2 (a) and (b) are PEA of Comparative Example 1. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution sample photos; (c) and (d) are PEA of Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 Photos of the SnI3 perovskite precursor solution at initial stage and after heating aging for 30 minutes.

[0046] Figure 3 PEA 0.1 (FA 0.75MA 0.25 ) 0.9 Comparison of X-ray photoelectron spectra of SnI3 perovskite films;

[0047] Figure 3 Where a and b represent the perovskite films prepared in Example 4 and Comparative Example 6, respectively.

[0048] Figure 4 This is a comparison diagram of the infrared spectra of the substance after the reaction of magnesium acetate with SnI2 and magnesium acetate. DETAILED DESCRIPTION

[0049] In order to more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0050] Example 1

[0051] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution includes phenethylammonium iodide (PEAI), iodomethane (FAI), iodomethane (MAI), stannous iodide (SnI2), magnesium acetate and a solvent, wherein the molar ratio of phenethylammonium iodide, iodomethane, iodomethane, stannous iodide and magnesium acetate is 0.1:0.675:0.225:1:0.1, and the solvent is dimethyl sulfoxide and dimethylformamide. It is prepared by the following method:

[0052] PEAI (25 mg), FAI (129 mg), MAI (40 mg), and SnI2 (373 mg) were added to 1 mL of a mixed solvent of dimethyl sulfoxide and dimethylformamide (volume ratio of 1:4) to obtain a mixed solution, 0.1 mmol of magnesium acetate was added to the mixed solution, and the PEA was obtained after mixing. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution.

[0053] Example 2

[0054] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that the amount of magnesium acetate added is 0.05 mmol.

[0055] Example 3

[0056] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that the amount of magnesium acetate added is 0.15 mmol.

[0057] Comparative Example 1

[0058] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that magnesium acetate is not added.

[0059] Comparative Example 2

[0060] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that magnesium acetate is replaced by potassium acetate.

[0061] Comparative Example 3

[0062] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that magnesium acetate is replaced by iron acetate.

[0063] Comparative Example 4

[0064] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that the amount of magnesium acetate added is 0.02 mmol.

[0065] Comparative Example 5

[0066] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is basically the same as that in Example 1, except that the amount of magnesium acetate added is 0.3 mmol.

[0067] Example 4

[0068] A PEA0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is prepared by the following method:

[0069] 60 μL of PEA prepared in Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution was dripped onto an ITO (Indium Tin Oxide) glass substrate and spin-coated at 4000 rpm for 50 seconds. 15 seconds after the start of spin coating, 120 μL of chlorobenzene antisolvent was continuously and evenly dripped onto the surface of the perovskite film during the spin coating process. After the spin coating was completed, the substrate coated with the perovskite precursor solution was placed on a hot plate at 120°C for annealing for 10 minutes to obtain antioxidant PEA. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

[0070] Example 5

[0071] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Example 2.

[0072] Example 6

[0073] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Example 3.

[0074] Comparative Example 6

[0075] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The precursor solution described in Comparative Example 1 in which magnesium acetate was not added to the SnI3 perovskite precursor solution was prepared.

[0076] Comparative Example 7

[0077] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 2.

[0078] Comparative Example 8

[0079] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 3.

[0080] Comparative Example 9

[0081] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 4.

[0082] Comparative Example 10

[0083] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is basically the same as Example 4, except that: PEA 0.1 (FA 0.75 MA0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 5.

[0084] Example 7

[0085] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cells are prepared by the following method:

[0086] P1. The ITO glass substrate was cleaned with acetone, ethanol, and deionized water, dried at high temperature, and a 40 nm layer of hole transport material PEDOT:PSS AI4083 was spin-coated on the treated ITO glass substrate.

[0087] P2. Add 70 μL of PEA prepared in Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was dripped onto the ITO glass substrate with hole transport material spin-coated, and the solution was spin-coated at a speed of 4500 rpm for 45 seconds. At 13 seconds after the start of spin coating, 140 μL of chlorobenzene antisolvent was continuously and evenly dripped onto the surface of the perovskite film in the process of spin coating. 0.1 (FA 0.75 MA 0.25 ) 0.9 The substrate of SnI3 perovskite precursor solution was placed on a hot plate at 100℃ and annealed for 11 minutes to obtain PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film, thickness 180nm;

[0088] P3. PEA obtained in P2 0.1 (FA 0.75 MA 0.25 ) 0.9 Electron transport material C was vacuum-deposited on SnI3 perovskite film 60 , interface modification material 2,9-dimethyl-4,7-diphenyl-1,10-o-phenanthroline (bathocuproine, abbreviation: BCP) and metal electrode Ag, with thicknesses of 40nm, 9nm and 100nm respectively.

[0089] Comparative Example 11

[0090] A PEA 0.1 (FA 0.75 MA 0.25 )0.9 SnI3 perovskite solar cell is basically the same as Example 7, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 1.

[0091] Comparative Example 12

[0092] A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cell is basically the same as Example 7, except that: PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was prepared in Comparative Example 2.

[0093] Experimental Example 1 Air oxidation test and air thermal stability aging test of perovskite precursor solution

[0094] 1. Experimental Methods

[0095] The PEA prepared in Examples 1 to 3 and Comparative Examples 1 to 5 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was placed in the air for oxidation testing. Specifically, equal volumes of each precursor solution were placed in a glass container. The glass container was kept open so that the precursor solution was in contact with the air. The color of the initial precursor solution and the color change of the precursor solution after 10 minutes of oxidation were observed to determine its oxidation status.

[0096] The PEA prepared in Examples 1 to 3 and Comparative Examples 1 to 5 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was placed in air for thermal stability aging testing. Specifically, the perovskite precursor solution was initially placed on a hot plate in air and aged for 30 minutes. The changes in the solution before and after heating at 120°C were then measured to determine its stability.

[0097] 2. Experimental Results

[0098] (1) Oxidation test results show that Examples 1-3 only have a small amount of Sn at the gas-liquid interface 2+ (bright yellow) is oxidized to Sn 4+(deep red), in Comparative Examples 1-5, the results of Comparative Examples 2 and 3 are the same as those of Example 1, indicating that acetate ions can 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution forms a protective layer. When the amount of magnesium acetate added in Comparative Example 4 is 0.02 mmol, the perovskite precursor solution is still severely oxidized over time, resulting in a large amount of deep red Sn 4+ The results of Comparative Example 5 are the same as those of Example 1. The reason is that the amount of magnesium acetate added is small and it is not possible to 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution can provide long-term protection, but when it is excessive, it can achieve the purpose of PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution for long-term protection. Figure 1 The PEA of Example 1 and Comparative Example 1 are shown. 0.1 (FA 0.75 MA 0.25 ) 0.9 Oxidation test results of SnI3 perovskite precursor solution exposed to air, PEA with magnesium acetate added in Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 After the SnI3 perovskite precursor solution was exposed to air for ten minutes, only a small amount of Sn was present at the gas-liquid interface. 2+ (bright yellow) is oxidized to Sn 4+ (deep red); while PEA without magnesium acetate in Comparative Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is severely oxidized, resulting in a large amount of deep red Sn 4+ The whole solution was dark red.

[0099] (2) The stability test results show that Examples 1-3 maintain bright yellow. Among Comparative Examples 1-5, Comparative Examples 2 and 3 show the same results as Example 1, maintaining bright yellow, indicating that acetate ions can stabilize PEA. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution forms a protective layer. When the amount of magnesium acetate added in Comparative Example 4 is 0.02 mmol, the stability of the perovskite precursor solution is poor over time, resulting in a large amount of deep red Sn4+ The results of Comparative Example 5 are the same as those of Example 1; the reason is that the amount of magnesium acetate added is small and it is not possible to 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution can provide long-term protection, but when it is excessive, it can achieve the purpose of PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution for long-term protection. Figure 2 The PEA of Example 1 and Comparative Example 1 are shown. 0.1 (FA 0.75 MA 0.25 ) 0.9 Comparison of thermal stability aging test of SnI3 perovskite precursor solution, PEA with magnesium acetate added in Example 1 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was well protected after heating and aging, and the perovskite precursor solution remained bright yellow; while the PEA of Comparative Example 1 without magnesium acetate was 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution has poor thermal stability, the perovskite precursor solution is severely oxidized, and the overall solution is orange-red.

[0100] This shows that the PEA of the present invention 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution contains a certain proportion of acetate ions that can react with Sn 2+ Combined to form a protective layer, it can protect the Sn in the perovskite precursor solution for a long time 2+ It is not oxidized in large quantities, which improves its stability. If there are too few acetate ions or no acetate ions, the antioxidant effect and stability will be poor.

[0101] Experimental Example 2: Sn inside the perovskite film 4+ Content test

[0102] 1. Experimental Methods

[0103] The PEA prepared in Examples 4 to 6 and Comparative Examples 6 to 10 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film for internal Sn 4+The test method is: using X-ray photoelectron spectroscopy to measure the content of PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film for internal Sn 4+ Content testing.

[0104] 2. Experimental Results

[0105] Figure 3 PEA prepared in Example 4 and Comparative Example 6 0.1 (FA 0.75 MA 0.25 ) 0.9 Comparison of X-ray photoelectron spectra of SnI3 perovskite films. It can be seen from the figure that PEA with magnesium acetate added in Example 4 0.1 (FA 0.75 MA 0.25 ) 0.9 Sn in the perovskite film prepared from SnI3 perovskite precursor solution 2+ Sn generated by oxidation 4+ Less than PEA without magnesium acetate in Comparative Example 6 0.1 (FA 0.75 MA 0.25 ) 0.9 Perovskite film prepared from SnI3 perovskite precursor solution.

[0106] The test results of Examples 5 to 6 are basically the same as those of Example 4. The test results of Comparative Examples 7 to 10 are as follows: PEA with an appropriate amount of potassium acetate added in Comparative Example 7 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, acetate ions inhibit Sn 2+ The potassium ion perovskite lattice fills the cell gap, causing the cell to expand. The prepared perovskite film has better crystallinity, but there are still deep defects in the perovskite film, resulting in poor photoelectric performance of the perovskite film. 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, although acetate ions can protect the perovskite precursor solution, iron ions are not very effective for PEA. 0.1 (FA 0.75 MA 0.25 ) 0.9 The preparation of SnI3 perovskite film does not have a positive effect. There are a lot of defects inside the perovskite film, the photoelectric performance is poor, and it is easily oxidized.4+ The content is relatively high. When the addition amount of magnesium acetate in Comparative Example 9 is 0.02mmol, the addition amount is small and the PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution is used for long-term protection to prepare PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film is also easily oxidized, resulting in Sn 4+ In comparative example 10, when the amount of magnesium acetate added was 0.3 mmol, although it was able to 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution is used for long-term protection, but excessive magnesium acetate has a significant adverse effect on the quality of the perovskite film, and the quality and photoelectric properties of the perovskite film are deteriorated.

[0107] Experimental Example 3 Infrared Spectrum Test of Perovskite Solar Cells

[0108] 1. Experimental Methods

[0109] The infrared spectrum test of the substance after the reaction of magnesium acetate and SnI2 and magnesium acetate is carried out. Specifically, the infrared spectrum test of the substance after the reaction of magnesium acetate and SnI2 and magnesium acetate is carried out using infrared spectroscopy.

[0110] The PEA prepared in Example 7 and Comparative Examples 11-12 0.1 (FA 0.75 MA 0.25 ) 0.9 The photoelectric performance of SnI3 perovskite solar cells was tested. The test method is: 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite solar cell was placed in the air and a standard simulated sunlight simulator (AM 1.5G, 100mW / cm 2 ) PEA was tested in a glove box filled with N2 atmosphere (O2<1ppm and H2O<0.1ppm). 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite solar cell is subjected to a current density-voltage (JV) characteristic test (under a standard sunlight), and the photoelectric conversion efficiency is measured and other related data are obtained.

[0111] 2. Experimental Results

[0112] The test results are as follows Figure 4 As shown, Figure 4 This is a comparison of the infrared spectra of the substance after the reaction of magnesium acetate with SnI2 and magnesium acetate. From the spectrum, it can be seen that the CO bond of magnesium acetate has moved significantly after contact with SnI2, indicating that magnesium acetate and Sn 2+ Interaction occurs, which can form a shielding layer to PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 Sn in SnI3 perovskite precursor solution 2+ Provides antioxidant protection.

[0113] As can be seen from Table 1, Example 7 PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 PEA prepared by adding magnesium acetate to SnI3 perovskite precursor solution 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cell and PEA prepared in comparative example 11 0.1 (FA 0.75 MA 0.25 ) 0.9 Compared with SnI3 perovskite solar cells, the photoelectric performance has been greatly improved; comparative example 12PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 PEA prepared by adding potassium acetate to SnI3 perovskite precursor solution 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cells, because potassium ions fill the perovskite lattice cell gap, causing the cell to expand, but most of the defects reduced are surface defects, and the filling of potassium ions is not stable, and deep defects in the perovskite film still exist, so the open circuit voltage of the perovskite solar cell is not significantly improved, and the PEA prepared in Example 7 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cells replace part of Sn due to the entry of magnesium ions into the perovskite unit cell. 2+The position of the perovskite film shrinks the unit cell, reduces the deep defect state of the perovskite film, and greatly improves the open circuit voltage of the perovskite solar cell, thereby improving the PEA. 0.1 (FA 0.75 MA 0.25 ) 0.9 Photovoltaic performance of SnI3 perovskite solar cells.

[0114] Table 1 Photoelectric performance parameters of Example 7 and Comparative Examples 11-12.

[0115]

[0116] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications may be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, characterized in that The invention comprises phenethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide, magnesium acetate and a solvent; the molar ratio of the phenethylammonium iodide, iodoformamidine, iodomethylamine, stannous iodide and magnesium acetate is 0.1:0.675:0.225:1:0.

1.

2. The PEA according to claim 1 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, characterized in that The solvent is dimethyl sulfoxide and / or dimethylformamide.

3. PEA according to claim 2 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite precursor solution, characterized in that The solvent is a mixed solvent consisting of dimethyl sulfoxide and dimethylformamide, and the volume ratio of dimethyl sulfoxide to dimethylformamide in the mixed solvent is 1:

4.

4. A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 The method for preparing SnI3 perovskite precursor solution is characterized in that: The steps include: Phenethylammonium iodide, iodomethane, iodomethane and stannous iodide are added to a solvent to obtain a mixed solution, and then magnesium acetate or its solution is added to the mixed solution and mixed evenly to obtain the PEA. 0.1 (FA 0.75 MA 0.25 ) 0.9 In the SnI3 perovskite precursor solution, the molar ratio of phenethylammonium iodide, iodomethane, iodomethane, stannous iodide, and magnesium acetate is 0.1:0.675:0.225:1:0.

1.

5. A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film, characterized in that Prepared by the following method: The PEA according to any one of claims 1 to 3 0.1 (FA 0.75 MA 0.25 ) 0.9 The SnI3 perovskite precursor solution was spin-coated on the substrate for 30-60 s. The anti-solvent was added 10-20 s after the start of spin-coating. 0.1 (FA 0.75 MA 0.25 ) 0.9 The substrate of SnI3 perovskite precursor solution is annealed to obtain PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

6. The PEA according to claim 5 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite film, characterized in that The anti-solvent is one of chlorobenzene, toluene, ethyl acetate, ether, dichloromethane and anisole.

7. The PEA according to any one of claims 5 to 6 0.1 (FA 0.75 MA 0.25 ) 0.9 Application of SnI3 perovskite thin films in the optoelectronic field.

8. A PEA 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite solar cell, comprising the PEA according to any one of claims 5 to 6 0.1 (FA 0.75 MA 0.25 ) 0.9 SnI3 perovskite thin film.

9. The PEA according to claim 8 0.1 (FA 0.75 MA 0.25 ) 0.9 Application of SnI3 perovskite solar cells in the photovoltaic field.

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