Preparation method of perovskite solar cell based on hexafluorophosphate doping

Abstract

The invention discloses a preparation method of a hexafluorophosphate doping-based perovskite solar cell, which comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an electron transport layer and an electrode layer from bottom to top, and is characterized in that hexafluorophosphate is doped in the perovskite light absorption layer. The invention further discloses a preparation method of the organic-inorganic hybrid perovskite solar cell doped with the hexafluorophosphate. According to the method, the hexafluorophosphate is doped in the perovskite precursor solution, so that the quality of the prepared perovskite film is improved, and the perovskite solar cell with excellent photoelectric performance is further prepared. The preparation process is simple, the cost is low, and commercialization of the perovskite solar cell is facilitated.

Description

Technical Field

[0001] The present invention belongs to the field of organic photoelectric technology, and in particular relates to a method for preparing a hexafluorophosphate-doped perovskite solar cell. Background Art

[0002] Photovoltaic technology is developing rapidly, and demand for this technology is expected to continue to grow, creating a promising market outlook. Perovskite materials possess properties such as adjustable band gap, high absorption coefficient, long carrier lifetime, and high mobility. These properties enable perovskite solar cells to demonstrate exceptional photoelectric conversion efficiency. Laboratory-certified single-cell efficiency has reached 26.95%, significantly approaching that of crystalline silicon cells. Furthermore, perovskite solar cells offer advantages in fabrication process and manufacturing cost, potentially replacing crystalline silicon cells in the future.

[0003] However, the long-term stability of perovskite solar cells remains a major challenge to their commercial viability. The stability of perovskite solar cells is affected by external environmental factors such as water, oxygen, light, and heat, as well as internal material composition and lattice defects. These factors can lead to cell performance degradation and device decomposition through various mechanisms. While the impact of these external conditions can be addressed through advanced packaging technologies, eliminating the inherent instability of perovskites is key to improving the performance and stability of perovskite solar cells.

[0004] Using passivating materials to reduce defects in perovskite materials has been shown to be an effective method for improving the optoelectronic performance and long-term stability of perovskite solar cells. Adding suitable additives to the perovskite precursor solution effectively passivates defects through interactions between the additive molecules and the perovskite components, improving the quality of the perovskite film. This synergistically improves the energy level matching between the perovskite layer and the charge transport layer, enhancing carrier extraction and transport capabilities. This is of great significance for improving the optoelectronic performance and stability of perovskite solar cells and advancing their commercialization. Summary of the Invention

[0005] To address the above technical issues, the primary objective of the present invention is to provide a method for preparing hexafluorophosphate-doped perovskite solar cells. By doping the perovskite precursor solution with hexafluorophosphate, the present invention improves the quality of the prepared perovskite film, thereby further producing a perovskite solar cell with excellent photoelectric performance.

[0006] To achieve the above objectives, the present invention employs a hexafluorophosphate-doped organic-inorganic hybrid perovskite solar cell comprising, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode layer, wherein the perovskite light-absorbing layer is doped with hexafluorophosphate. The technical solution comprises the following steps:

[0007] Step 1: ultrasonically clean the conductive glass substrate with deionized water, acetone, and ethanol solutions in sequence, blow dry with nitrogen, and then treat in a UV-ozone cleaning machine for 10 to 30 minutes;

[0008] Step 2: Assemble a hole transport layer or SAM layer on the substrate surface by coating or evaporation;

[0009] Step 3: coating a hexafluorophosphate-doped perovskite precursor solution on the hole transport layer obtained in step 2, and annealing to obtain a perovskite light absorbing layer;

[0010] Step 4: coating an electron transport material on the obtained perovskite light absorbing layer and annealing to obtain an electron transport layer;

[0011] Step 5: Vapor-depositing electrode materials on the electron transport layer obtained in step 4 to obtain the organic-inorganic hybrid perovskite solar cell.

[0012] Preferably, the hole transport layer in step 2 includes polynickel oxide, cuprous oxide, cuprous sulfide, cuprous thiocyanate, and cuprous iodide; and the SAM layer includes Me-4PACz, Me-2PACz, MeO-4PACz, 4PACz, MeO-2PACz, 2PACz, Me-4PADCB, etc.

[0013] Preferably, in step 3, the hexafluorophosphate-doped perovskite precursor solution is prepared by adding hexafluorophosphate to the perovskite precursor solution and stirring for 1 to 2 hours.

[0014] Preferably, in step 3, the preparation method of the hexafluorophosphate-doped perovskite precursor solution is: adding hexafluorophosphate to the perovskite precursor solution and stirring for 1 to 2 hours.

[0015] Preferably, the hexafluorophosphate structural formula is:

[0016]

[0017] Preferably, the doping amount of the hexafluorophosphate in the perovskite precursor solution is 0.1 to 5 mg / mL.

[0018] Preferably, in step 3, the annealing temperature is 100-150° C., and the time is 10-60 min.

[0019] Preferably, in step 3, an anti-solvent is added dropwise during the process of coating the hexafluorophosphate-doped perovskite precursor solution on the hole transport layer.

[0020] Preferably, the anti-solvent comprises ether, ethyl acetate, chlorobenzene or anisole.

[0021] Preferably, in step 4, the electron transport material is PC 61 BM chlorobenzene solution, the PC 61 The concentration of the chlorobenzene solution of BM is 10 to 30 mg / mL.

[0022] Preferably, in step 4, the annealing temperature is 50-100° C. and the time is 5-10 minutes.

[0023] Preferably, after step 4, the method further comprises coating an electron transport modification material on the electron transport layer and annealing to obtain the electron transport modification layer.

[0024] Preferably, the electron transport modification material is an isopropanol solution of BCP, and the concentration of the solution is 0.3-1.0 mg / mL.

[0025] Preferably, the annealing temperature for preparing the electron transport modification layer is 100-150° C., and the time is 1-10 minutes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The perovskite light-absorbing layer of the organic-inorganic hybrid perovskite solar cell of the present invention contains hexafluorophosphate, and the -PF6 - Uncoordinated Pb in the perovskite light-absorbing layer 2+ As well as the halide vacancy, a strong coordination effect is generated, and the cation in the hexafluorophosphate interacts with the uncoordinated I - / Br - The strong coordination effect of cation vacancies can effectively improve the crystallinity and internal defects of perovskite. At the same time, hexafluorophosphate can adjust the energy level matching between the perovskite layer and the charge transport layer, improve the extraction and transport capacity of carriers, reduce the residual stress of the perovskite layer, and effectively improve the intrinsic stability of the perovskite material, thereby further improving the photoelectric performance and stability of perovskite solar cells.

[0028] (2) The present invention improves the film-forming quality of the perovskite light-absorbing layer by doping hexafluorophosphate into the perovskite precursor solution, thereby significantly increasing the open-circuit voltage, current density, and fill factor of the prepared solar cell, providing a new method for preparing high-efficiency perovskite solar cell devices.

[0029] (3) The perovskite solar cell of the present invention has a simple preparation process, low cost, and excellent photoelectric performance and stability, which is conducive to the commercialization of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1This is a schematic structural diagram of a hexafluorophosphate-doped perovskite solar cell prepared in the present invention;

[0031] Figure 2 JV curves of the perovskite solar cells prepared in the examples and comparative examples of the present invention;

[0032] Figure 3 The SEM images of the perovskite light-absorbing layers prepared in the examples and comparative examples of the present invention are shown in FIG. Figure 3 (a) is a SEM image of the perovskite light-absorbing layer of the comparative example; Figure 3 (b) is a SEM image of the perovskite light-absorbing layer of the embodiment;

[0033] Figure 4 AFM images of the perovskite light absorbing layers prepared in the examples and comparative examples of the present invention, wherein Figure 4 (a) is an AFM image of the perovskite light absorbing layer of the comparative example; Figure 4 (b) is an AFM image of the perovskite light-absorbing layer of the embodiment. DETAILED DESCRIPTION

[0034] To make the objectives, features, and advantages of the present invention more readily apparent, exemplary embodiments are described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different drawings represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application.

[0035] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. As used in this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0036] In the examples of the present invention, if the specific conditions are not specified, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are conventional products that can be obtained by conventional techniques or purchased commercially.

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] It should be noted that, unless there is any conflict, the features in the following embodiments and implementations may be combined with each other.

[0039] In the examples of the present invention, if the specific conditions are not specified, the experiments were carried out according to conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are conventional products that can be obtained by conventional techniques or purchased commercially.

[0040] Example

[0041] like Figure 1 As shown, the doped perovskite solar cell device structure in this embodiment is: ITO / SAM / perovskite active layer / PC 61 BM / BCP / Ag.

[0042] The method for preparing a hexafluorophosphate-doped perovskite solar cell in an embodiment of the present invention comprises the following steps:

[0043] Step 1: The etched ITO glass was ultrasonically cleaned with deionized water, acetone, and ethanol solutions in sequence, dried with nitrogen, and then treated in a UV-ozone cleaning machine for 20 minutes to obtain a clean ITO conductive glass substrate.

[0044] Step 2: Dissolve 1 mg of Me-4PADCB (SAM) in 1 mL of anhydrous ethanol and stir at room temperature for 2 hours. Add 100 μL of the Me-4PADCB ethanol solution to an ITO substrate and spin-coat at 4000 rpm for 40 seconds. Anneal the ITO substrate coated with the Me-4PADCB ethanol solution at 100°C for 10 minutes to form a hole transport layer.

[0045] Step 3: Dissolve 661.3 mg of PbI2, 226.7 mg of FAI, 7.75 mg of MABr, 25.4 mg of PbBr2, 10.17 mg of MACl and 21.1 mg of CsI in 1 mL of a mixed solvent of DMF and DMSO (the molar ratio of DMF to DMSO is 4:1), add 0.2 mg of hexafluorophosphate, and stir for 2 h to obtain 1 mL of a 0.2 mg / mL hexafluorophosphate-doped perovskite precursor solution. 60 μL of the prepared hexafluorophosphate-doped perovskite precursor solution was added dropwise to the hole transport layer obtained in step 2, and the solution was first spin-coated at 1000 rpm for 10 seconds, and then at 3000 rpm for 30 seconds. At the 25th second, 200 μL of chlorobenzene was added as an anti-solvent. The substrate coated with the perovskite wet film was annealed at 100° C. for 50 minutes to obtain a perovskite light-absorbing layer. The structural formula of the hexafluorophosphate used in this embodiment is as follows:

[0046]

[0047] Step 4: Add 2mg PC 61 BM was dissolved in 1 mL of chlorobenzene to prepare PC 61 BM solution. Add 60 μL of PC 61 The BM chlorobenzene solution was dropped onto the perovskite light-absorbing layer obtained in step 3, and spin-coated at a rotation speed of 1500 rpm for 60 s. The substrate was annealed at 70° C. for 5 min to obtain an electron transport layer.

[0048] Step 5: Dissolve 0.5 mg of BCP in 1 mL of isopropanol to prepare a BCP solution. Drop 100 μL of the BCP solution onto the electron transport layer obtained in step 4 and spin coat at 5000 rpm for 30 seconds to obtain an electron transport modification layer.

[0049] Step 6: Using vacuum thermal evaporation technology, 80 nm thick silver is evaporated on the electron transport modification layer obtained in step 5 as an electrode to obtain a hexafluorophosphate-doped perovskite solar cell.

[0050] Comparative Example

[0051] Part of the content in step 3 of Example 1 was replaced with the following: 661.3 mg of PbI2, 226.7 mg of FAI, 7.75 mg of MABr, 25.4 mg of PbBr2, 10.17 mg of MACl, and 21.1 mg of CsI were dissolved in 1 mL of a mixed solvent of DMF and DMSO (the molar ratio of DMF to DMSO was 4:1) to obtain an undoped perovskite precursor solution. 60 μL of the undoped perovskite precursor solution was dropwise added to the hole transport layer obtained in step 2. All other contents were the same as those in Example 1.

[0052] Performance Testing

[0053] The performance of the perovskite solar cells prepared in the Examples and Comparative Examples was tested under standard testing conditions (AM 1.5G illumination). The performance parameters of the perovskite solar cells obtained in the Examples and Comparative Examples, including photoelectric conversion efficiency, open-circuit voltage, short-circuit current, and fill factor, are detailed in Table 1.

[0054] Table 1

[0055]

[0056] From Table 1 and Figure 2 It can be seen that hexafluorophosphate doping promotes the improvement of short-circuit current, open-circuit voltage and fill factor of perovskite solar cell devices, thereby increasing the energy conversion efficiency from 23.90% in the comparative example to 25.46% in the embodiment. This result confirms the improvement effect of hexafluorophosphate on photovoltaic performance.

[0057] Figure 3The SEM images of the perovskite light absorbing layer of the embodiment and the comparative example are shown in FIG. Figure 3 (a) is a SEM image of the perovskite light-absorbing layer of the comparative example; Figure 3 (b) is a SEM image of the perovskite light absorbing layer of the embodiment. Figure 3 (a) and Figure 3 From the comparison of (b), it can be seen that after hexafluorophosphate treatment, the crystal shape of perovskite is more regular, the grain size is larger and more uniform, the crystallinity is higher, and the film defects are fewer, which will be beneficial to the extraction and transmission of carriers, thereby improving the photovoltaic performance and stability of the device.

[0058] Figure 4 The AFM images of the perovskite light absorbing layer of the embodiment and the comparative example are shown in FIG. Figure 4 (a) is an AFM image of the perovskite light absorbing layer of the comparative example; Figure 4 (b) is an AFM image of the perovskite light absorbing layer of the embodiment. Figure 4 (a) and Figure 4 (b) shows that the surface roughness of the perovskite light absorbing layer of the embodiment is significantly reduced, the surface of the film is smoother, and the defect density is lower, which is consistent with the Figure 3 The characterization results are consistent.

[0059] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the contents disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed in this application.

[0060] It will be understood that the present application is not limited to the exact construction that has been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof.

Claims

1. A method for preparing a hexafluorophosphate-doped perovskite solar cell, characterized in that: The invention comprises, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and an electrode layer, wherein the perovskite light-absorbing layer is doped with hexafluorophosphate; and the method for preparing a perovskite solar cell comprises the following steps: (1) The conductive glass substrate was ultrasonically cleaned with deionized water, acetone, and ethanol solutions in sequence, dried with nitrogen, and then treated in a UV-ozone cleaning machine for 10 to 30 minutes; (2) assembling a hole transport layer or SAM layer on the substrate surface by coating or evaporation; (3) coating a hexafluorophosphate-doped perovskite precursor solution on the hole transport layer obtained in step (2), and annealing to obtain a perovskite light absorbing layer; (4) coating an electron transport material on the obtained perovskite light absorbing layer and annealing to obtain an electron transport layer; (5) Vapor-depositing electrode materials on the electron transport layer obtained in step (4) to obtain the organic-inorganic hybrid perovskite solar cell.

2. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The hole transport layer in step (2) includes polynickel oxide, cuprous oxide, cuprous sulfide, cuprous thiocyanate, and cuprous iodide; the SAM layer includes Me-4PACz, Me-2PACz, MeO-4PACz, 4PACz, MeO-2PACz, 2PACz, and 4PADCB.

3. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The perovskite precursor solution in step (3) comprises a perovskite material and a precursor solvent, wherein the perovskite material comprises FAPbI3, MAPbBr3 or CsPb(I x Br 1-x )3, wherein 0<x<1 or more; the precursor solvent includes at least one of N,N-dimethylformamide, dimethyl sulfoxide or N-methylpyrrolidone.

4. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The hexafluorophosphate-doped perovskite precursor solution in step (3) is prepared by adding hexafluorophosphate to the perovskite precursor solution and stirring for 1 to 2 hours.

5. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The hexafluorophosphate structural formula is:

6. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The doping amount of the hexafluorophosphate in the perovskite precursor solution in the step (3) is 0.1 to 5 mg / mL.

7. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The annealing temperature in step (3) is 100-150° C., and the annealing time is 10-60 minutes.

8. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: In the process of coating the hexafluorophosphate-doped perovskite precursor solution on the hole transport layer in step (3), an anti-solvent needs to be added dropwise; the anti-solvent includes diethyl ether, ethyl acetate, chlorobenzene or anisole.

9. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The annealing temperature in step (4) is 50-100° C. and the annealing time is 5-10 minutes.

10. The method for preparing a hexafluorophosphate-doped perovskite solar cell according to claim 1, wherein: The method also includes coating an electron transport modification material on the electron transport layer and annealing to obtain the electron transport modification layer; the electron transport modification material is an isopropanol solution of BCP, and the concentration of the solution is 0.3 to 1.0 mg / mL; the annealing temperature during the preparation of the electron transport modification layer is 100 to 150° C. and the time is 1 to 10 minutes.

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