Perovskite solar cell prepared by using trifluoromethanesulfonate in air and preparation method thereof

Abstract

The invention discloses a perovskite solar cell prepared from trifluoromethanesulfonate in air and a preparation method of the perovskite solar cell. The trifluoromethanesulfonate is a compound containing trifluoromethanesulfonate ions and metal cations, the trifluoromethanesulfonate is doped into a perovskite precursor solution, and the perovskite solar cell is prepared under the condition of an air environment (the humidity is 25%-65%). Compared with a perovskite thin film without trifluoromethanesulfonate, the perovskite thin film has the advantages that the film forming effect is good, the repeatability and the uniformity of the perovskite thin film are obviously improved, and the photoelectric conversion efficiency of the perovskite solar cell finally prepared from the perovskite thin film and the trifluoromethanesulfonate is relatively close; the method for preparing the perovskite solar cell in the air by using the trifluoromethanesulfonate is insensitive to the change of the environmental humidity, and the environmental adaptability in the preparation process of the perovskite thin film is enhanced by adding the trifluoromethanesulfonate, so that the perovskite solar cell with stable efficiency can be obtained under different humidity conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of perovskite solar cells, and specifically relates to a perovskite solar cell prepared in air using trifluoromethanesulfonate and a preparation method thereof. Background Art

[0002] Perovskite solar cells have shown great potential in future practical applications due to their excellent photoelectric conversion efficiency, low cost and simple solution preparation route. However, currently high-efficiency perovskite solar cells are mainly prepared by spin coating, which results in serious waste of raw materials and cannot achieve large-scale continuous preparation. In addition, the preparation process often needs to be carried out in an inert gas environment to prevent the perovskite material from reacting with water and oxygen, which leads to a decrease in the performance of perovskite solar cells and cannot meet the needs of industrial production.

[0003] At present, the main problems in preparing perovskite solar cells in air are the impact on the quality of perovskite film formation, the selection and optimization of solvents, and the stability of perovskite precursor solutions. Humidity has a significant impact on the preparation of perovskite films. Halogen perovskites are extremely sensitive to water in the air environment, which leads to a decrease in the quality of perovskite films, thus affecting the uniformity and stability of perovskite films, and ultimately affecting the performance and stability of perovskite solar cells.

[0004] Current research shows that the preparation of perovskite solar cells in air has potential cost advantages, but a series of technical and environmental challenges still need to be overcome to achieve stable efficiency and preparation under high humidity. By improving the preparation process and optimizing the equipment configuration, it is expected that more efficient and economical perovskite solar cell production will be achieved in the future. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a perovskite solar cell prepared in air using trifluoromethanesulfonate and a preparation method thereof. The present application doped trifluoromethanesulfonate into a perovskite precursor solution, and the perovskite precursor solution doped with trifluoromethanesulfonate can stably form a film in an environment with humidity and oxygen, thereby enhancing the environmental adaptability of the perovskite film preparation process. The perovskite film formation effect is better than that of the perovskite film without the addition of trifluoromethanesulfonate, and the repeatability and uniformity of the preparation of the perovskite film are significantly improved, so that a perovskite solar cell with stable efficiency can be obtained under different humidity conditions.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A method for preparing a perovskite solar cell in air using trifluoromethanesulfonate comprises the following steps:

[0008] (1) The FTO conductive glass substrate was ultrasonically treated with glass cleaning agent, deionized water, anhydrous ethanol, acetone, and isopropanol for 15 minutes respectively, and then subjected to ultraviolet irradiation for 20 minutes for standby use;

[0009] (2) doping trifluoromethanesulfonate into the perovskite precursor solution, stirring and mixing evenly, and aging for 12 hours to obtain a trifluoromethanesulfonate-doped perovskite precursor solution for standby use;

[0010] (3) spin coating a nickel oxide isopropanol solution at a speed of 4000 r / min for 30 seconds on the surface of the FTO conductive glass substrate treated in step (1), and then annealing on a heating table at 100° C. for 10 minutes to obtain a dense nickel oxide hole transport layer;

[0011] (4) Spin coating the triflate-doped perovskite precursor solution obtained in step (2) on the dense nickel oxide hole transport layer obtained in step (3) at a speed of 1500 r / min for 30 seconds, and annealing at 150° C. for 30 minutes to obtain a triflate-doped perovskite absorption layer;

[0012] (5) Spin coating the pre-prepared [6,6]-phenyl-C61 butyric acid methyl ester on the triflate-doped perovskite absorber layer obtained in step (4) at a speed of 6000 r / min for 30 s, and annealing at 100° C. for 10 min;

[0013] (6) The FTO conductive glass substrate coated with [6,6]-phenyl-C61 butyric acid methyl ester in step (5) is transferred to a vacuum evaporation chamber for vacuum evaporation. The rate of vacuum evaporation is A fullerene derivative electron transport layer with a thickness of 8 nm is obtained;

[0014] (7) transferring the FTO conductive glass substrate on which the fullerene derivative electron transport layer has been evaporated in step (6) to a vacuum evaporation chamber for evaporation of metal, vacuum evaporation The rate of vacuum evaporation is A metal electrode with a thickness of 80nm is obtained, completing the preparation of the perovskite solar cell.

[0015] Furthermore, in step (2), the trifluoromethanesulfonate salt is trifluoromethanesulfonic anhydride or trifluoromethanesulfonate ion and a metal cation, and the cation comprises lithium, sodium or potassium.

[0016] Furthermore, the trifluoromethanesulfonate is any one of lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate or trifluoromethanesulfonic anhydride.

[0017] Furthermore, the specific preparation method of the doped triflate perovskite precursor solution in step (2) is as follows: lead iodide, methylammonium iodide, and triflate in a mass ratio of 5.98:1.7:0.017 are dissolved in an organic solvent and stirred to mix evenly to obtain a doped triflate perovskite precursor solution.

[0018] Furthermore, the concentration of the trifluoromethanesulfonate is 0.1-2.8 mg / mL; and the organic solvent is any one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and N-ethyl-2-pyrrolidone.

[0019] Furthermore, the concentration of the nickel oxide isopropanol solution in step (3) is 2.5 mg / ml.

[0020] Furthermore, the triflate-doped perovskite absorption layer in step (4) is prepared under the condition of air humidity of 25-65%.

[0021] Furthermore, the concentration of the pre-prepared [6,6]-phenyl-C61 butyric acid methyl ester in step (5) is 2.5 mg / ml.

[0022] Furthermore, the metal electrode in step (7) is any one of a metal gold electrode, a metal silver electrode and a metal copper electrode.

[0023] Furthermore, a perovskite solar cell prepared by the method of preparing a perovskite solar cell in air using trifluoromethanesulfonate as mentioned above, wherein the perovskite solar cell comprises, in sequence, an FTO conductive electrode, a nickel oxide hole transport layer, a trifluoromethanesulfonate-doped perovskite absorption layer, a fullerene derivative electron transport layer and a metal electrode.

[0024] Compared with the prior art, the present invention has the following positive and beneficial effects:

[0025] The present invention prepares a perovskite solar cell device in an air environment (humidity 25%-65%) by doping trifluoromethanesulfonate into a perovskite precursor solution. The perovskite film-forming effect is better than that of a perovskite film without adding trifluoromethanesulfonate, and the repeatability and uniformity of the perovskite film are significantly improved. The photoelectric conversion efficiency of the perovskite solar cells finally prepared by the two is relatively close, indicating that the method of the present invention for preparing the perovskite solar cell in the air by using trifluoromethanesulfonate is not sensitive to changes in environmental humidity. The addition of trifluoromethanesulfonate enhances the environmental adaptability in the process of preparing the perovskite film, so that a perovskite solar cell with stable efficiency can be obtained under different humidity conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1Schematic diagram of the chemical structure of trifluoromethanesulfonate used in the present invention;

[0027] Figure 2 It is a schematic structural diagram of a perovskite solar cell device prepared in the air using trifluoromethanesulfonate according to the present invention;

[0028] Figure 3 The present invention is a trend diagram of the photoelectric conversion efficiency of the perovskite solar cell device prepared in the air using trifluoromethanesulfonate and not using trifluoromethanesulfonate under different air humidity (25-65%) conditions. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the technical solution of the present invention is further described below in conjunction with the embodiments and drawings. The embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0030] The chemical structure diagram of the trifluoromethanesulfonate used in the following examples of the present invention is as follows Figure 1 shown.

[0031] Example 1

[0032] A method for preparing a perovskite solar cell using potassium trifluoromethanesulfonate in air comprises the following steps:

[0033] (1) The FTO conductive glass substrate was ultrasonicated with glass cleaning agent, deionized water, anhydrous ethanol, acetone, and isopropanol for 15 minutes respectively, and then irradiated with ultraviolet light for 20 minutes before use;

[0034] (2) Lead iodide, methylammonium iodide and potassium trifluoromethanesulfonate in a mass ratio of 5.98:1.7:0.017 are dissolved in a mixed solution of N,N-dimethylformamide and N-ethyl-2-pyrrolidone in a volume ratio of 6:1, stirred and mixed evenly, and aged for 12 hours to obtain a potassium trifluoromethanesulfonate-doped perovskite precursor solution for standby use, wherein 1.55 mg of potassium trifluoromethanesulfonate is doped, and the concentration range is 0.1-2.8 mg / mL;

[0035] (3) Spin coating a 2.5 mg / ml nickel oxide isopropanol solution at a speed of 4000 r / min for 30 seconds on the surface of the FTO conductive glass substrate treated in step (1), and then annealing at 100° C. on a heating table for 10 minutes to obtain a dense nickel oxide hole transport layer;

[0036] (4) Under the condition of air humidity of 35%, the potassium trifluoromethanesulfonate-doped perovskite precursor solution obtained in step (2) is spin-coated at a speed of 1500 r / min for 30 seconds on the dense nickel oxide hole transport layer obtained in step (3), and annealed at 150° C. for 30 minutes to obtain a trifluoromethanesulfonate-doped perovskite absorption layer.

[0037] (5) Spin coating the pre-prepared [6,6]-phenyl-C61 butyric acid methyl ester with a concentration of 2.5 mg / ml at a speed of 6000 r / min for 30 seconds on the potassium trifluoromethanesulfonate-doped perovskite absorption layer obtained in step (4), and annealing at 100° C. for 10 minutes;

[0038] (6) The FTO conductive glass substrate coated with [6,6]-phenyl-C61 butyric acid methyl ester in step (5) is transferred to a vacuum evaporation chamber for vacuum evaporation. The rate of vacuum evaporation is A fullerene derivative electron transport layer with a thickness of 8 nm is obtained;

[0039] (7) The FTO conductive glass substrate on which the fullerene derivative electron transport layer has been evaporated in step (6) is transferred to a vacuum evaporation chamber for evaporation of gold and silver. The rate of vacuum evaporation is The metal electrode silver with a thickness of 80nm is obtained, and the preparation of the perovskite solar cell is completed. The structural schematic diagram of the obtained perovskite solar cell is shown in Figure 2 shown.

[0040] Example 2

[0041] The method for preparing a perovskite solar cell in this embodiment is the same as that in Example 1, except that the perovskite precursor solution is doped with 1.55 mg of sodium trifluoromethanesulfonate, and the concentration range is 0.1-2.5 mg / mL.

[0042] Example 3

[0043] The method for preparing a perovskite solar cell in this embodiment is the same as that in Example 1, except that the perovskite precursor solution is doped with 1.4 mg of lithium trifluoromethanesulfonate, and the concentration range is 0.1-0.9 mg / mL.

[0044] Example 4

[0045] The method for preparing a perovskite solar cell in this embodiment is the same as that in embodiment 1, except that the perovskite precursor solution is doped with 2.54 mg of trifluoromethanesulfonic anhydride, the concentration of which is in the range of 0.1-3.1 mg / mL, and the preparation is carried out under a humidity of 35%.

[0046] The method for preparing the perovskite solar cell in this comparative example is the same as that in Example 1, except that no triflate is added during the preparation process.

[0047] The performance data of the perovskite solar cells prepared in Examples 1-4 of the present invention and Comparative Example 1 are shown in Table 1.

[0048] Table 1 Performance data of the perovskite solar cells prepared in Examples 1-4 and Comparative Example 1

[0049]

[0050] It can be seen from the data in Table 1 that the present invention prepares a perovskite film by doping a perovskite precursor solution with trifluoromethanesulfonate under an air humidity of 35%. Compared with the perovskite precursor solution doped with trifluoromethanesulfonate, the photoelectric conversion efficiency of the perovskite solar cells obtained by the two methods is relatively close, indicating that the method of preparing a perovskite solar cell in the air using trifluoromethanesulfonate is insensitive to changes in the humidity of the air environment, so that a perovskite solar cell with stable photoelectric conversion efficiency can be obtained under different air humidity conditions, and has the advantage of low cost, while ensuring the output of high-quality perovskite films; for different trifluoromethanesulfonates, the photoelectric properties of the material can be optimized by adjusting the difference in cations, and finally a perovskite solar cell with excellent photoelectric properties under an air humidity of 35% is prepared.

[0051] Depend on Figure 3 It can be seen that the perovskite solar cell prepared without triflate doping perovskite precursor solution ( Figure 3 Compared with the lower curve in the middle), the present invention uses trifluoromethanesulfonate to prepare perovskite solar cells in air ( Figure 3 The upper middle curve shows that a perovskite solar cell with a high photoelectric conversion efficiency can be obtained when the air humidity is 25-65%, especially when the air humidity is 35%, the photoelectric conversion efficiency of the perovskite solar cell reaches the highest. This is because the present invention uses trifluoromethanesulfonate to prepare the perovskite solar cell, and the trifluoromethanesulfonate can passivate the defects of the perovskite film, and the fluoride ions in the trifluoromethanesulfonate can also form a stable MA with the cationic amino group in the perovskite. + and FA + , thus inhibiting the generation of perovskite cation vacancies and weakening the binding ability of perovskite with water, thereby improving the photoelectric conversion efficiency in an air environment (25%-65%).

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

[0053] The present invention and its implementation methods are described above, which is not restrictive. The drawings are only one of the implementation methods of the present invention, and the actual application is not limited thereto. In short, if ordinary technicians in the field are inspired by it and design methods and embodiments similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a perovskite solar cell in air using trifluoromethanesulfonate, characterized in that: The following steps are involved: (1) The FTO conductive glass substrate was ultrasonically treated with glass cleaning agent, deionized water, anhydrous ethanol, acetone, and isopropanol for 15 minutes respectively, and then subjected to ultraviolet irradiation for 20 minutes for standby use; (2) doping trifluoromethanesulfonate into the perovskite precursor solution, stirring and mixing evenly, and aging for 12 hours to obtain a trifluoromethanesulfonate-doped perovskite precursor solution for standby use; (3) coating the surface of the FTO conductive glass substrate treated in step (1) with a nickel oxide isopropanol solution by spin coating at a speed of 4000 r / min for 30 seconds, and then annealing at 100° C. on a heating platform for 10 minutes to obtain a dense nickel oxide hole transport layer; (4) Spin coating the triflate-doped perovskite precursor solution obtained in step (2) on the dense nickel oxide hole transport layer obtained in step (3) at a speed of 1500 r / min for 30 s, and then annealing at 150° C. for 30 min to obtain a triflate-doped perovskite absorption layer; (5) Spin coating the pre-formulated [6,6]-phenyl-C61 butyric acid methyl ester on the triflate-doped perovskite absorber layer obtained in step (4) at a speed of 6000 r / min for 30 s, and then annealing at 100° C. for 10 min; (6) The FTO conductive glass substrate coated with [6,6]-phenyl-C61 butyric acid methyl ester in step (5) is transferred to a vacuum evaporation chamber for vacuum evaporation. The rate is A fullerene derivative electron transport layer with a thickness of 8 nm is obtained; (7) transferring the FTO conductive glass substrate on which the fullerene derivative electron transport layer has been evaporated in step (6) to a vacuum evaporation chamber for evaporation of metal, vacuum evaporation The rate is A metal electrode with a thickness of 80nm is obtained, completing the preparation of the perovskite solar cell.

2. A method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 1, characterized in that: In the step (2), the trifluoromethanesulfonate salt is trifluoromethanesulfonic anhydride or trifluoromethanesulfonate ion and a metal cation, and the metal cation is any one of lithium, sodium and potassium.

3. A method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 2, characterized in that: The trifluoromethanesulfonate is any one of lithium trifluoromethanesulfonate, sodium trifluoromethanesulfonate, potassium trifluoromethanesulfonate or trifluoromethanesulfonic anhydride.

4. The method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 1, characterized in that: The specific preparation method of the doped triflate perovskite precursor solution in step (2) is as follows: lead iodide, methylammonium iodide and triflate in a mass ratio of 5.98:1.7:0.017 are dissolved in an organic solvent and stirred to mix evenly to obtain a doped triflate perovskite precursor solution.

5. A method for preparing a perovskite solar cell in air using trifluoromethanesulfonate according to claim 4, characterized in that: The concentration of the trifluoromethanesulfonate is 0.1-2.8 mg / mL; the organic solvent is any one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone and N-ethyl-2-pyrrolidone.

6. A method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 1, characterized in that: The concentration of the nickel oxide isopropanol solution in step (3) is 2.5 mg / ml.

7. The method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 1, characterized in that: The trifluoromethanesulfonate-doped perovskite absorption layer in step (4) is prepared under the condition of air humidity of 25-65%.

8. The method for preparing a perovskite solar cell in air using trifluoromethanesulfonate according to claim 1, characterized in that: The concentration of the pre-formulated [6,6]-phenyl-C61 butyric acid methyl ester in step (5) is 2.5 mg / ml.

9. The method for preparing a perovskite solar cell using trifluoromethanesulfonate in air according to claim 1, characterized in that: In the step (7), the metal electrode is any one of a gold electrode, a silver electrode and a copper electrode.

10. A perovskite solar cell prepared by the method for preparing a perovskite solar cell in air using trifluoromethanesulfonate as claimed in any one of claims 1 to 9, characterized in that: The perovskite solar cell comprises in sequence an FTO conductive electrode, a nickel oxide hole transport layer, a trifluoromethanesulfonate-doped perovskite absorption layer, a fullerene derivative electron transport layer and a metal electrode.

Images