Double-layer perovskite thin film and preparation method and application thereof

Abstract

The invention discloses a double-layer perovskite thin film and a preparation method and application thereof. The invention belongs to the technical field of photoelectric devices. The preparation method comprises the following steps: S1, mixing a FASnI3 precursor solution and an MAPbI3 precursor solution, coating the surface of a pretreated transfer printing medium with the mixed solution, and carrying out spin coating and annealing through an anti-solvent method to obtain a transfer printing medium containing a (FASnI3) 1-x (MAPbI3) x perovskite thin film; x is 0.1 to 1; and S2, carrying out hot pressing on the transfer printing medium containing the (FASnI3) 1-x (MAPbI3) x perovskite thin film and the FAPbI3 perovskite thin film, and removing the transfer printing medium to obtain the double-layer perovskite thin film. According to the method, the preparation quality and efficiency of the double-layer perovskite thin film are improved; the light absorption range of the perovskite thin film is widened, and the photoelectric conversion efficiency of a solar cell prepared from the double-layer perovskite thin film is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a double-layer perovskite film and a preparation method and application thereof. Background Art

[0002] Perovskite solar cells have become a research hotspot due to their high efficiency, low cost and low-temperature preparation. However, the widely used FAPbI3 perovskite has a wide band gap and a limited absorption spectrum, which limits the further improvement of its photoelectric conversion efficiency. In addition, the traditional solution spin coating method is difficult to directly apply to the preparation of double-layer perovskites because the solvent used to prepare the second layer of perovskites will destroy the previous layer of perovskites.

[0003] Therefore, it is necessary to develop a new method for preparing double-layer perovskite films. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the first aspect of the present invention provides a method for preparing a double-layer perovskite film, wherein the double-layer perovskite film prepared by the method has high quality, a wide light absorption range, and high photoelectric conversion efficiency.

[0005] The second aspect of the present invention also provides a double-layer perovskite film.

[0006] The third aspect of the present invention also provides a perovskite solar cell.

[0007] According to a first aspect of the present invention, a method for preparing a double-layer perovskite film is provided, comprising the following steps:

[0008] S1, coating the FASnI3 precursor solution and the MAPbI3 precursor solution on the pretreated transfer medium surface, spin coating and annealing by anti-solvent method to obtain a (FASnI3) 1-x (MAPbI3) x Transfer medium of perovskite film; x is 0.1 to 1;

[0009] S2, will contain (FASnI3) 1-x (MAPbI3) x The transfer medium of the perovskite film is hot-pressed with the FAPbI3 perovskite film, and the transfer medium is removed to obtain a double-layer perovskite film.

[0010] The preparation method according to the embodiment of the present invention has at least the following beneficial effects:

[0011] The present invention uses a transfer medium to prepare a double-layer perovskite film by a physical transfer method; it avoids the damage of the front perovskite film by a chemical solution method, and improves the preparation quality and efficiency of the double-layer perovskite film. 1-x (MAPbI3) x The components of the perovskite film reduce the interaction with the transfer medium and increase its transferability. Furthermore, the double-layer perovskite film broadens the light absorption range of the perovskite film and improves the photoelectric conversion efficiency of the solar cell prepared by the double-layer perovskite film.

[0012] According to some embodiments of the present invention, the transfer medium is selected from at least one of polydimethylsiloxane, polyethylene terephthalate film, polyimide film, polycarbonate film, polyurethane film, silicone rubber or hydrogel. Thus, when the transfer medium is selected from the above substances, it has a high transfer ability.

[0013] According to some embodiments of the present invention, in step S2, the pressure of the hot pressing is 20MPa to 80MPa. If the pressure of the hot pressing is too high, the film may break easily, and if the pressure is too low, the contact between the films may not be complete, resulting in incomplete transfer. Therefore, when the hot pressing pressure of the present invention is within the above range, the transfer effect is better.

[0014] According to some embodiments of the present invention, in step S2, the temperature of the hot pressing is 50° C. to 150° C. For example, 80° C., 100° C., 120° C., 150° C. or a sub-range consisting of any numerical values ​​is selected.

[0015] According to some embodiments of the present invention, in step S2, the heat pressing time is 2 minutes to 10 minutes. If the heat pressing time is too short, the reaction will be incomplete and the contact will be incomplete. If the heat pressing time is too long, it will cause an over-reaction.

[0016] According to some embodiments of the present invention, the FAPbI3 perovskite film is prepared by the following method:

[0017] The FAPbI3 perovskite precursor solution is coated on the surface of the electron transport layer containing the glass substrate and annealed to obtain the product.

[0018] According to some embodiments of the present invention, the annealing temperature is 50° C. to 150° C. Therefore, when the annealing temperature is within the above range, the prepared film has high quality.

[0019] According to some embodiments of the present invention, the annealing time is 1 min to 10 min.

[0020] According to some embodiments of the present invention, the method for pre-treating the transfer medium is: treating the surface of the transfer medium with oxygen plasma, thereby enhancing the wettability of the perovskite film and improving the quality of the perovskite film.

[0021] A double-layer perovskite film provided in an embodiment according to the second aspect of the present invention is prepared by the preparation method described in the first aspect of the present invention.

[0022] The third aspect of the present invention provides a perovskite solar cell, comprising the double-layer perovskite film described in the second aspect of the present invention.

[0023] According to some embodiments of the present invention, the perovskite solar cell further comprises a hole transport layer and a metal electrode sequentially disposed on the surface of the double-layer perovskite film.

[0024] According to some embodiments of the present invention, there is no requirement for the material selection of the hole transport layer, and it can be any conventional material used in the art, such as spiro-OMeTAD (CAS No.: 207739-72-8), PTAA (CAS No.: 1333317-99-9), nickel oxide-based film, CuO or CuSCN.

[0025] According to some embodiments of the present invention, the metal electrode includes gold, silver or copper.

[0026] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of the preparation process of Example 1 of the present invention;

[0029] Figure 2 Schematic diagram of the principle of a perovskite solar cell prepared in an embodiment of the present invention;

[0030] Figure 3 is a JV curve diagram of a perovskite solar cell prepared by a double-layer perovskite film provided in Example 1 of the present invention;

[0031] Figure 4 This is an external quantum efficiency diagram of a perovskite solar cell prepared with a double-layer perovskite film provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0033] Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0034] Example 1

[0035] This example provides a double-layer perovskite film, and the schematic diagram of its preparation process is as follows Figure 1 As shown, the preparation method is as follows:

[0036] Tin-lead perovskite precursor solution: Weigh a certain molar ratio of FASnI3 (formamidinium tin lead) and MAPbI3 (methylamine lead iodide) powders, dissolve them in a mixed solvent of dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) to prepare a precursor solution with a total concentration of 1.2 M, where FASnI3:MAPbI3=0.7:0.3.

[0037] Transfer medium: Polydimethylsiloxane (PDMS) was selected as the transfer medium, and the PDMS surface was treated with an oxygen plasma cleaner for 10 minutes; the PDMS was cut into thin sheets of appropriate size for later use.

[0038] Glass substrate: Use cleaned indium tin oxide (ITO) conductive glass as the target substrate, and pre-deposit a layer of electron transport layer (SnO2); the thickness is 20nm; obtain an ITO / SnO2 substrate for use.

[0039] S1. Fix the prepared PDMS sheet on a spin coater, drop 50uL of tin-lead perovskite precursor solution, spin coat at a certain speed (3000rpm) for 30 seconds, and then pre-anneal on a hot stage at 100℃ for 5 minutes to remove part of the solvent;

[0040] The pre-annealed PDMS sheet was quickly dipped into the anti-solvent chlorobenzene to induce rapid crystallization of the perovskite film, and then taken out and annealed in a dry environment (150°C, 30 minutes) to obtain a film containing (FASnI3) 0.7 (MAPbI3) 0.3 Transfer medium for perovskite thin films;

[0041] S2. On an ITO / SnO2 substrate, a layer of FAPbI3 perovskite film was prepared by spin coating, and annealed on a hot stage (150°C, 10 minutes) to obtain a well-crystallized FAPbI3 film; the PDMS sheet of the prepared tin-lead perovskite film was brought into contact with the FAPbI3 film on the ITO / SnO2 substrate, and a hot press was used to perform transfer treatment at a specific temperature and pressure (120°C, 40MPa) for 5 minutes to transfer the tin-lead perovskite film from the PDMS to the FAPbI3 film to form a double-layer perovskite structure; the PDMS sheet was removed to obtain a double-layer perovskite film (the thickness of FAPbI3 is 400nm; (FASnI3) 0.7 (MAPbI3) 0.3 The thickness is 200 nm).

[0042] Example 2

[0043] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing pressure is 80 MPa.

[0044] Example 3

[0045] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing pressure is 20 MPa.

[0046] Example 4

[0047] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing pressure is 10 MPa.

[0048] Example 5

[0049] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing pressure is 100 MPa.

[0050] Example 6

[0051] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that FASnI3:MAPbI3=0.4:0.6; (FASnI3) is obtained. 0.4 (MAPbI3) 0.6 Perovskite thin films.

[0052] Example 7

[0053] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the transfer medium is a polyethylene terephthalate film.

[0054] Example 8

[0055] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing temperature is 80°C.

[0056] Example 9

[0057] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing temperature is 100°C.

[0058] Example 10

[0059] This example provides a double-layer perovskite film, and its preparation method is basically the same as that of Example 1, except that the hot pressing temperature is 150°C.

[0060] Performance Testing

[0061] The double-layer perovskite film prepared in Examples 1 to 10 of the present invention is prepared into a perovskite solar cell, and its principle schematic diagram is as follows Figure 2 As shown, the steps are as follows: a hole transport layer (spiro-OMeTAD; thickness 150nm) and a silver electrode (thickness 100nm) are sequentially deposited on the double-layer perovskite film of Examples 1 to 10. The photoelectric performance of the device is tested using a solar simulator, the current-voltage (JV) curve is recorded, and the photoelectric conversion efficiency is calculated. The results are shown in Table 1.

[0062] Table 1 Data of Examples 1 to 10

[0063] Photoelectric conversion efficiency / % Open circuit voltage / V <![CDATA[Short-circuit current / mA / cm 2 > Fill Factor EQE Absorption Range Example 1 24.73 1.12 27.26 0.81 ~1000nm Example 2 24.06 1.11 27.10 0.80 ~1000nm Example 3 24.31 1.12 26.80 0.81 ~1000nm Example 4 16.33 1.12 23.53 0.62 ~1000nm Example 5 14.35 1.04 20.29 0.68 ~1000nm Example 6 24.52 1.12 26.70 0.82 ~1000nm Example 7 24.70 1.15 26.85 0.80 ~1000nm Example 8 23.37 1.09 27.15 0.79 ~1000nm Example 9 24.67 1.13 26.95 0.81 ~1000nm Example 10 23.21 1.12 26.57 0.78 ~1000nm

[0064] The current-voltage curve of the perovskite solar cell prepared by the double-layer perovskite film provided in Example 1 is as follows: Figure 3 As shown, from Figure 3 As can be seen, a photoelectric conversion efficiency of 24.73% was obtained; the open circuit voltage was 1.12 V, and the short circuit current was 27.26 mA / cm 2 ; The filling factor is 0.81.

[0065] Furthermore, the external quantum efficiency of the perovskite solar cell prepared by the double-layer perovskite film provided in Example 1 is as follows: Figure 4 As shown, the EQE absorption range is broadened to nearly 1000nm; the light absorption range is broadened.

[0066] From the data in Table 1, it can be seen that the embodiment of the present invention uses a transfer medium to prepare a double-layer perovskite film by a physical transfer method; the damage to the front perovskite film by a chemical solution method is avoided, and the preparation quality and efficiency of the double-layer perovskite film are improved. 1-x (MAPbI3) xThe components of the perovskite film reduce the interaction with the transfer medium and increase its transferability. Furthermore, the double-layer perovskite film broadens the light absorption range of the perovskite film and improves the photoelectric conversion efficiency of the solar cell prepared by the double-layer perovskite film.

[0067] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A method for preparing a double-layer perovskite film, characterized in that: The steps include: S1, coating the FASnI3 precursor solution and the MAPbI3 precursor solution on the pretreated transfer medium surface, spin coating and annealing by anti-solvent method to obtain a (FASnI3) 1-x (MAPbI3) x Transfer medium of perovskite film; x is 0.1 to 1; S2, will contain (FASnI3) 1-x (MAPbI3) x The transfer medium of the perovskite film is hot-pressed with the FAPbI3 perovskite film, and the transfer medium is removed to obtain a double-layer perovskite film.

2. The method for preparing a double-layer perovskite film according to claim 1, characterized in that: The transfer medium is selected from at least one of polydimethylsiloxane, polyethylene terephthalate film, polyimide film, polycarbonate film, polyurethane film, silicone rubber or hydrogel.

3. The method for preparing a double-layer perovskite film according to claim 1 or 2, characterized in that: In step S2, the hot pressing pressure is 20 MPa to 80 MPa.

4. The method for preparing a double-layer perovskite film according to claim 1 or 3, characterized in that: In step S2, the temperature of the hot pressing is 50°C to 150°C; Preferably, the hot pressing time is 2 min to 10 min.

5. The method for preparing a double-layer perovskite film according to claim 1 or 3, characterized in that: The method for pre-treating the transfer medium comprises: The surface of the transfer medium is treated with oxygen plasma.

6. The method for preparing a double-layer perovskite film according to claim 1, characterized in that: The FAPbI3 perovskite film is prepared by the following method: The FAPbI3 perovskite precursor solution is coated on the surface of the electron transport layer containing the glass substrate and annealed to obtain the product.

7. The method for preparing a double-layer perovskite film according to claim 6, characterized in that: The annealing temperature is 50°C to 150°C.

8. The method for preparing a double-layer perovskite film according to claim 6, characterized in that: The annealing time is 1 min to 10 min.

9. A double-layer perovskite film, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 8.

10. A perovskite solar cell, characterized in that: Comprising the double-layer perovskite film as described in claim 9.

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