Perovskite thin film passivation method, perovskite solar cell and preparation method of perovskite solar cell

Abstract

The invention provides a passivation method of a perovskite thin film, a perovskite solar cell and a preparation method of the perovskite solar cell, and belongs to the technical field of perovskite solar cells. The passivation method comprises the following steps: S1, dissolving fluconazole in a solvent to obtain a passivation solution; s2, coating a perovskite thin film with the passivation solution to obtain a wet passivation film; and S3, the wet passive film is dried, and the passive film is obtained. According to the passivation method, the passivation film is introduced between the perovskite thin film and the electron transport layer or the hole transport layer, the interface defect state density of the perovskite thin film is reduced, the photoelectric conversion efficiency and the stability of the perovskite solar cell are improved, and the performance and the service life of the perovskite solar cell can be remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and particularly relates to a passivation method for perovskite thin films, a perovskite solar cell, and a preparation method thereof. Background Art

[0002] Perovskite solar cells have attracted much attention in recent years due to their high photoelectric conversion performance and low-cost manufacturing process, and the photoelectric conversion efficiency has rapidly increased from the initial 4% to more than 26%. However, the interface defect problem of perovskite thin films seriously restricts the device performance and stability. Specifically, there are a large number of unsaturated bonds and defect states at the interfaces between the perovskite thin film and the electron transport layer (ETL) and the hole transport layer (HTL). These defects will cause non-radiative recombination of carriers, reducing the open-circuit voltage, short-circuit current, and fill factor of the battery, thereby reducing the photoelectric conversion efficiency of the battery. In addition, the defects at the interface are also prone to cause chemical instability of the perovskite thin film and accelerate device degradation.

[0003] To solve these problems, researchers have proposed an interface passivation technology. By introducing a passivation material, such as an organic molecule, a halide salt, or an oxide, between the perovskite thin film and the electron / hole transport layer, it can effectively repair interface defects, reduce non-radiative recombination, and improve device efficiency and stability. However, how to select suitable passivation materials and processes remains a difficulty and challenge in current research. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this purpose, an embodiment of the present invention provides a passivation method for perovskite thin films and a perovskite solar cell. The passivation method reduces the density of interface defect states of the perovskite thin film through the application of a passivation material, improves the photoelectric conversion efficiency and stability of the perovskite solar cell, and can significantly improve the performance and lifespan of the perovskite solar cell.

[0005] An embodiment of the present invention provides a passivation method for perovskite thin films, including the following steps:

[0006] S1. Dissolve fluconazole in a solvent to obtain a passivation solution;

[0007] S2. Coat the passivation solution on the perovskite thin film to obtain a wet passivation film;

[0008] S3. Dry the wet passivation film to obtain a passivation film.

[0009] The advantages and technical effects brought by the passivation method of the embodiment of the present invention are:

[0010] (1) In the passivation method of the embodiments of the present invention, fluconazole is used as an interfacial modification molecule / passivation material and is coated on the surface of the perovskite film to form a passivation film. Subsequently, after preparing an electron transport layer or a hole transport layer on the passivation film, a passivation film is introduced between the perovskite film and the electron transport layer or the hole transport layer, and chemical or physical interactions are formed between it and the perovskite film or the transport layer, thereby reducing the perovskite interface defects. The passivation film can interact with the unsaturated bonds or charged defects at the perovskite interface to eliminate the perovskite interface defects. Therefore, the obtained perovskite solar cell has higher photoelectric conversion efficiency and better stability, and can significantly improve the performance and lifespan of the perovskite solar cell.

[0011] (2) By selecting fluconazole with lower cost as the interfacial modification molecule / passivation material, the manufacturing cost of the perovskite solar cell can also be effectively reduced.

[0012] In some embodiments, in the passivation solution, the concentration of fluconazole is 0.01 - 2 mg / mL.

[0013] In some embodiments, the solvent is isopropyl alcohol and / or trifluoroethanol.

[0014] In some embodiments, the coating method of the passivation solution is spin coating, dip coating, blade coating or slot die coating.

[0015] In some embodiments, the coating amount of the passivation solution is 80 - 150 μL of the passivation solution per square centimeter of the perovskite film.

[0016] In some embodiments, the holding temperature of the drying treatment is 80 - 120 °C, and the holding time of the drying treatment is 5 - 30 min.

[0017] In addition, the embodiments of the present invention provide a perovskite solar cell, in which a passivation film is provided between the perovskite film and the electron transport layer, or a passivation film is provided between the perovskite film and the hole transport layer, and the material of the passivation film is fluconazole.

[0018] The advantages and technical effects brought by the passivation method of the embodiments of the present invention are as follows:

[0019] (1) A passivation film made of fluconazole is introduced between the perovskite film and the electron transport layer or the hole transport layer, and chemical or physical interactions are formed between it and the perovskite film or the transport layer, thereby reducing the perovskite interface defects. In addition, the passivation film can interact with the unsaturated bonds or charged defects at the perovskite interface to eliminate the perovskite interface defects. Therefore, the obtained perovskite solar cell has higher photoelectric conversion efficiency and better stability, and can significantly improve the performance and lifespan of the perovskite solar cell.

[0020] (2) By selecting fluconazole with lower cost as the interfacial modification molecule / passivation material, the manufacturing cost of perovskite solar cells can also be effectively reduced.

[0021] In addition, the embodiment of the present invention also provides a preparation method of a perovskite solar cell. The passivation film is prepared by the following passivation method, and the passivation method includes the following steps:

[0022] S1. Dissolve fluconazole in a solvent to obtain a passivation solution;

[0023] S2. Coat the passivation solution on the perovskite film to obtain a wet passivation film;

[0024] S3. Dry the wet passivation film to obtain a passivation film.

[0025] The advantages and technical effects brought by the preparation method of the perovskite solar cell in the embodiment of the present invention are as follows:

[0026] Since the passivation method in the embodiment of the present invention is adopted to prepare the passivation film, a passivation film made of fluconazole is introduced between the perovskite film and the electron transport layer or the hole transport layer. Therefore, the preparation method of the perovskite solar cell in the embodiment of the present invention can effectively improve the photoelectric conversion efficiency and stability of the battery.

[0027] In some embodiments, the concentration of fluconazole is 0.01 - 2 mg / mL.

[0028] In some embodiments, the coating amount of the passivation solution is 80 - 150 μL of the passivation solution per square centimeter of the perovskite film. Description of the Drawings

[0029] Figure 1 is the structural formula of fluconazole.

[0030] Figure 2 are the current-voltage curve graphs of the perovskite solar cells before and after aging in Example 1 and Comparative Example 1. Detailed Embodiments

[0031] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

[0032] The embodiment of the present invention provides a passivation method for a perovskite film, including the following steps:

[0033] S1. Dissolve fluconazole (the structural formula is as Figure 1 shown) in a solvent to obtain a passivation solution;

[0034] S2. Coating the passivation solution on the perovskite film to obtain a wet passivation film;

[0035] S3. Drying the wet passivation film to obtain a passivation film.

[0036] In the passivation method of the embodiment of the present invention, fluconazole is coated on the surface of the perovskite film as an interfacial modification molecule / passivation material to form a passivation film. Subsequently, after preparing an electron transport layer or a hole transport layer on the passivation film, a passivation film is introduced between the perovskite film and the electron transport layer or the hole transport layer. The triazole group in the fluconazole molecule can interact with the inorganic skeleton in the perovskite, and the fluorinated benzene ring in the fluconazole molecule can form a hydrophobic surface, thereby effectively passivating interface defects and reducing the erosion of moisture on the film, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell. In addition, by selecting the relatively low-cost fluconazole as the interfacial modification molecule / passivation material, the manufacturing cost of the perovskite solar cell can be effectively reduced.

[0037] In some embodiments, in the passivation solution, the concentration of fluconazole is 0.01 - 2 mg / mL, such as 0.01 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, etc. When the concentration of fluconazole in the passivation solution is too low, the thickness of the passivation film obtained with the same coating amount of the passivation solution is too small, which is not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell. When the concentration of fluconazole in the passivation solution is too high, it is not conducive to the uniform coating of the passivation solution, and it is also not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0038] In some embodiments, the solvent is isopropyl alcohol and / or trifluoroethanol. The above alcohol solvents have good solubility for fluconazole and are more easily evaporated and removed when drying the wet passivation film after coating the passivation solution.

[0039] In some embodiments, the coating method of the passivation solution is spin coating, dip coating, blade coating or slot coating, etc. The above-listed coating methods can uniformly coat the passivation solution on the perovskite surface.

[0040] In some embodiments, the coating amount of the passivation solution is 80 - 150 μL of the passivation solution per square centimeter of the perovskite film. When the coating amount of the passivation solution is too small, the thickness of the obtained passivation film is too small, which is not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell. When the coating amount of the passivation solution is too large, cracks are likely to appear in the perovskite film, which will reduce the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0041] In some embodiments, the heat preservation temperature of the drying treatment is 80 - 120 °C, such as 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, etc., and the heat preservation time of the drying treatment is 5 - 30 min, such as 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc. When the heat preservation temperature of the drying treatment is too low or the heat preservation time is too short, it is not conducive to quickly removing the solvent in the wet passivation film to obtain the passivation film. When the heat preservation temperature of the drying treatment is too high or the heat preservation time is too long, it is not conducive to cost reduction and efficiency improvement.

[0042] In addition, an embodiment of the present invention provides a perovskite solar cell, in which a passivation film is provided between the perovskite thin film and the electron transport layer, or a passivation film is provided between the perovskite thin film and the hole transport layer, and the material of the passivation film is fluconazole.

[0043] The perovskite solar cell of the embodiment of the present invention introduces a passivation film made of fluconazole between the perovskite thin film and the electron transport layer or the hole transport layer. The triazole group in the fluconazole molecule can interact with the inorganic skeleton in the perovskite, and the fluorobenzene ring in the fluconazole molecule can form a hydrophobic surface, thereby effectively passivating interface defects and reducing the erosion of moisture on the thin film, thereby improving the photoelectric conversion efficiency and stability of the perovskite solar cell. In addition, by selecting fluconazole with a lower cost as the interface modification molecule / passivation material, the manufacturing cost of the perovskite solar cell can be effectively reduced.

[0044] It should be noted that the structure of a conventional perovskite solar cell is a conductive substrate / electron transport layer / perovskite thin film / hole transport layer / optionally a buffer layer / electrode. Therefore, the structure of the perovskite solar cell prepared by the passivation method of the embodiment of the present invention is a conductive substrate / electron transport layer / perovskite thin film / passivation layer / hole transport layer / optionally a buffer layer / electrode, and a passivation film is introduced between the perovskite thin film and the hole transport layer. The structure of a reverse perovskite solar cell is a conductive substrate / hole transport layer / perovskite thin film / electron transport layer / optionally a buffer layer / electrode. Therefore, the structure of the perovskite solar cell prepared by the passivation method of the embodiment of the present invention is a conductive substrate / hole transport layer / perovskite thin film / passivation layer / electron transport layer / optionally a buffer layer / electrode, and a passivation film is introduced between the perovskite thin film and the electron transport layer.

[0045] In addition, an embodiment of the present invention also provides a preparation method of a perovskite solar cell, and the passivation film is prepared by using the following passivation method, and the passivation method includes the following steps:

[0046] S1. Dissolve fluconazole in a solvent to obtain a passivation solution;

[0047] S2. Coat the passivation solution on the perovskite thin film to obtain a wet passivation film;

[0048] S3. Dry the wet passivation film to obtain a passivation film.

[0049] Since the passivation method of the embodiment of the present invention is used to prepare the passivation film, a passivation film made of fluconazole is introduced between the perovskite film and the electron transport layer or the hole transport layer. Therefore, the preparation method of the perovskite solar cell of the embodiment of the present invention can effectively improve the photoelectric conversion efficiency and stability of the battery.

[0050] In some embodiments, the concentration of fluconazole is 0.01 - 2 mg / mL.

[0051] In some embodiments, the coating amount of the passivation liquid is 80 - 150 μL of the passivation liquid per square centimeter of the perovskite film.

[0052] The present invention will be described in detail below with reference to embodiments and drawings.

[0053] Example 1

[0054] (1) Clean a (1×1 cm 2 ) ITO conductive glass, and magnetron sputter a 10 - nm - thick nickel oxide film on the ITO conductive glass as a hole transport layer.

[0055] (2) Dissolve lead iodide, lead bromide, formamidinium iodide, and cesium iodide with a molar ratio of 0.85:0.15:0.78:0.22 in a mixed solution of DMF and DMSO with a volume ratio of 4:1 and mix evenly to obtain a perovskite precursor solution. Spin - coat the perovskite precursor solution on the surface of the nickel oxide film by the one - step method at a rotation speed of 3000 rpm for 30 s, and add the antisolvent ethyl acetate at the 20th second of spin - coating to obtain a perovskite wet film. Then anneal the film at 100 °C for 20 min to obtain a 600 - nm - thick perovskite film.

[0056] (3) Dissolve fluconazole in isopropanol to obtain a 0.5 - mg / mL passivation liquid, and then spin - coat the passivation liquid on the surface of the perovskite film according to the dosage of 80 μL of the passivation liquid per square centimeter of the perovskite film at a rotation speed of 4000 rpm for 30 s to obtain a wet passivation film. Then dry the film at 100 °C for 10 min to obtain a passivation film.

[0057] (4) Place the sample prepared above in a vacuum thermal evaporation chamber. When the air pressure in the evaporation chamber is lower than 1×10 -5 Pa, start to evaporate C 60 at an evaporation rate of 0.2 nm / s and deposit it on the perovskite film to obtain a 30 - nm - thick C 60 layer; then evaporate BCP at an evaporation rate of 0.1 nm / s and deposit it on C 60A BCP layer with a thickness of 3 nm is formed on the layer; finally, Cu is evaporated at an evaporation rate of 0.5 nm / s and deposited on the BCP layer to form a Cu electrode layer with a thickness of 100 nm, and thus a perovskite solar cell is obtained.

[0058] Example 2

[0059] The method of this example is the same as that of Example 1, except that the concentration of the passivation solution is 1 mg / mL.

[0060] Example 3

[0061] The method of this example is the same as that of Example 1, except that the concentration of the passivation solution is 2 mg / mL.

[0062] Example 4

[0063] The method of this example is the same as that of Example 1, except that the solvent used to prepare the passivation solution is trifluoroethanol.

[0064] Comparative Example 1

[0065] The method of this comparative example is the same as that of Example 1, except that step (3) is omitted, and the perovskite solar cell obtained lacks a passivation film.

[0066] Performance Test

[0067] The perovskite solar cells obtained in each example and comparative example were subjected to photoelectric conversion efficiency tests. The test results are shown in Table 1, and then they were stored in a glove box for 60 days of aging, and the photoelectric conversion efficiency tests are shown in Table 1. The current-voltage curve graphs of the perovskite solar cells of Example 1 and Comparative Example 1 before and after aging are as Figure 2 shown.

[0068] Table 1. Photoelectric conversion efficiency of perovskite solar cells in each example and comparative example

[0069]

[0070] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0071] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A passivation method for a perovskite film, characterized in that: The following steps are involved: S1. dissolving fluconazole in a solvent to obtain a passivation solution; S2. applying the passivation solution on the perovskite film to obtain a wet passivation film; S3. Drying the wet passivation film to obtain a passivation film.

2. The passivation method according to claim 1, characterized in that: In the passivation solution, the concentration of fluconazole is 0.01-2 mg / mL.

3. The passivation method according to claim 1 or 2, characterized in that: The solvent is isopropanol and / or trifluoroethanol.

4. The passivation method according to claim 1 or 2, characterized in that: The passivation solution is coated by spin coating, dip coating, blade coating or slit coating.

5. The passivation method according to claim 1 or 2, characterized in that: The coating amount of the passivation solution is 80-150 μL per square centimeter of the perovskite film.

6. The passivation method according to claim 1 or 2, characterized in that: The heat preservation temperature of the drying process is 80-120° C., and the heat preservation time of the drying process is 5-30 minutes.

7. A perovskite solar cell, characterized in that: A passivation film is arranged between the perovskite film and the electron transport layer, or a passivation film is arranged between the perovskite film and the hole transport layer, and the material of the passivation film is fluconazole.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that: The passivation film is prepared by the following passivation method, which comprises the following steps: S1. dissolving fluconazole in a solvent to obtain a passivation solution; S2. applying the passivation solution on the perovskite film to obtain a wet passivation film; S3. Drying the wet passivation film to obtain a passivation film.

9. The preparation method according to claim 8, characterized in that: In the passivation solution, the concentration of fluconazole is 0.01-2 mg / mL.

10. The preparation method according to claim 8, characterized in that: The coating amount of the passivation solution is 80-150 μL per square centimeter of the perovskite film.

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