A method for preparing multiple stable perovskite films based on supramolecular modification anti-solvent

Abstract

The application discloses a method for preparing a multiple-stable perovskite film based on supramolecular modification of anti-solvent, introduces dimethoxy pillar[5]arene into the anti-solvent, utilizes the host-guest inclusion confinement effect of the rigid columnar macrocyclic cavity of the dimethoxy pillar[5]arene on perovskite organic cations, the multitooth coordination passivation effect of the peripheral methoxy on uncoordinated Pb 2+ , and the molecular-level mechanical anchoring function of the macrocyclic skeleton at the grain boundary, cooperatively constructs a trinity ion migration inhibition network of encapsulation, anchoring and blocking, and synchronously realizes the inhibition of cation migration and halogen ion migration, the inhibition of the formation of non-light-active delta phase and the molecular spring type stress self-release. The flexible solar cell based on the film is prepared in an air environment, and a photoelectric conversion efficiency of 22.43% and a low hysteresis effect are obtained, and after 1000 bending cycles at a bending radius of 5 mm, the normalized efficiency retention rate reaches 79.48%, which exhibits significantly improved multiple stability and mechanical durability.

Description

Technical Field

[0001] This invention belongs to the field of new energy materials technology, specifically relating to a supramolecularly modified multi-stable perovskite thin film and its preparation method for solar cells. Background Technology

[0002] As a clean and renewable energy source, solar energy is a key means to address the energy dilemma and environmental challenges. Since its initial report in 2009, perovskite solar cells have attracted significant attention in the photovoltaic field due to their remarkable speed of power conversion efficiency improvement. However, perovskite materials exhibit inherent brittleness, and defects such as grain boundaries and vacancies are prevalent in their polycrystalline thin films. These defects severely restrict the application of perovskite materials in flexible devices. Therefore, there is an urgent need to provide a modification strategy that can simultaneously achieve defect passivation, enhanced photoelectric performance, and improved stability in multiple ways.

[0003] This application introduces dimethoxy columnar aromatic hydrocarbon (DMP5) with a supramolecular macrocyclic structure[5] as an antisolvent modifier into the preparation of perovskite films for the first time. The working principle of DMP5 is based on its multiple synergistic mechanisms and has significant uniqueness: DMP5 is a rigid columnar macrocyclic molecule composed of five 1,4-dimethoxybenzene units connected by methylene para-bridges. It has an electron-rich hydrophobic cavity with a diameter of about 5 Å, which can be distinguished from conventional adsorption or simple bonding. During the crystallization process of perovskite, the cavity of DMP5 selectively partially encapsulates the organic cations in the perovskite precursor components through host-guest recognition, forming a stable inclusion complex, thereby giving it a function different from conventional additives: spatially restricting the degree of freedom of cations, regulating crystallization kinetics, and fundamentally inhibiting subsequent ion migration, thus achieving a confined encapsulation effect. The rigid columnar framework structure of DMP5 can form molecular-level fixation at the grain boundaries, effectively dispersing and transferring mechanical stress when the film is subjected to bending deformation, which is fundamentally different from the stress buffering of flexible polymers through chain segment movement. This invention utilizes supramolecular materials to regulate perovskite crystallization, passivate defects, and protect interfaces, potentially driving the development of more efficient and stable optoelectronic devices. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0006] Therefore, the purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing high-quality perovskite thin films modified by supramolecular technology and their application in the field of solar cells.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing a multi-stable perovskite thin film modified by supramolecular means, wherein the perovskite thin film is obtained by spin-coating a perovskite precursor solution onto a charge transport layer by a one-step antisolvent method, and during this process, an antisolvent containing a supramolecular modifier is rapidly dropped from above the film, followed by a thermal annealing process; In a preferred embodiment of the preparation method described in this invention, the perovskite precursor solution comprises a solute and a solvent. The solute is one or more of the following: methylammonium chloride, methylammonium bromide, lead chloride, lead thiocyanate, lead iodide, lead bromide, lead acetate, stannous iodide, stannous bromide, cesium iodide, cesium bromide, rubidium iodide, methylammonium iodide, methylammonium bromide, methylammonium iodide, n-butylamine iodide, and methylammonium chloride. The solvent is N,N-dimethylformamide, N-methyl-2-dimethylformamide, etc. - One or more of pyrrolidone, ionic liquid, dimethyl sulfoxide, and γ-butyrolactone; the antisolvent is one or more of chlorobenzene, isopropanol, tert-butanol, ethyl acetate, toluene, and diethyl ether; the supramolecular modifier is one or more of dimethoxyl[5]arene (DMP5), calix[4]arene, calix[5]arene, calix[6]arene, calix[8]arene, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, crown ether, cucurbita, cyclosporine, calixpyrrole, and cyclic peptide.

[0008] In a preferred embodiment of the preparation method described in this invention, the concentration of the supramolecular modifier in the antisolvent is 0.01–15.0 mg / ml; the supramolecular modifier and the antisolvent are mixed and heated at 20–45 °C and stirred at 200–450 rpm for 0.5–2.5 h.

[0009] As a preferred embodiment of the preparation method described in this invention, the method for preparing the perovskite precursor solution includes mixing the solute and solvent, heating at 40–80 °C, and stirring at 200–450 rpm for 0.5–3.5 h.

[0010] As a preferred embodiment of the preparation method described in this invention, the method for preparing the perovskite precursor solution includes mixing the solute and solvent, heating at 50–70 °C, and stirring at 200–500 rpm for 0.5–2 h.

[0011] In a preferred embodiment of the preparation method described in this invention, the spin coating step lasts for 10-35 seconds and is divided into two segments. The first segment lasts for 3-18 seconds, during which the rotation speed increases from rest to 1800 rpm at an acceleration of 200-450 rpm / s and remains thereafter until the end of the first segment. The second segment lasts for 7-17 seconds without interruption, during which the rotation speed increases from 1800 rpm to 3800 rpm at an acceleration of 300-800 rpm / s and remains thereafter until the end of the second segment.

[0012] In a preferred embodiment of the preparation method described in this invention, the annealing temperature is 90~170 ℃ and the time is 5~55 min.

[0013] In a preferred embodiment of the preparation method described in this invention, the volume ratio of the antisolvent to the perovskite precursor solution is 6~66:6.

[0014] Another objective of this invention is to overcome the shortcomings of the prior art and provide a high-quality perovskite thin film prepared by a supramolecular modified antisolvent spin-coating method.

[0015] As a preferred embodiment of the high-quality perovskite thin film of the present invention, the thickness of the supramolecular modified perovskite thin film is 300~800 nm; the relative humidity in the air environment is 25~75%, and the temperature is 25~40 ℃.

[0016] Another objective of this invention is to overcome the shortcomings of the prior art and provide a high-quality flexible perovskite thin film for use in solar cells.

[0017] This invention is the first to introduce the principle of macrocyclic supramolecular chemistry of columnar aromatic hydrocarbons into the field of perovskite photovoltaics. Through the synergistic effect of the confinement and encapsulation effect of rigid columnar cavities, the multi-site synergistic anchoring and passivation mechanism, and the mechanical bearing function of the macrocyclic rigid framework, multiple unique improvement effects such as ion migration inhibition, delta phase inhibition, and molecular spring self-repair are achieved. These effects are not only not recorded in previous applications, but also cannot be achieved by conventional molecular additives and polymer additives in terms of mechanism.

[0018] Beneficial effects of this invention: (1) This invention employs a novel supramolecular modified antisolvent spin-coating technique. When the color of the perovskite precursor liquid film begins to change (a key intervention window for precisely triggering rapid and uniform nucleation), DMP5-modified chlorobenzene is injected into the film from directly above. The confinement and encapsulation effect of the DMP5 columnar cavities on the cations not only stabilizes the organic cations themselves in the perovskite lattice, but its spatial occupancy effect also simultaneously blocks halide ions (I2). - ,Br -Migration pathways along grain boundaries. Simultaneously, peripheral ether oxygen bonds affect Pb. 2+ The anchoring further stabilizes the inorganic framework six-ligand configuration, forming a three-in-one ion migration inhibition network of "encapsulation-anchoring-blocking" from three dimensions. This fundamentally inhibits cation migration, halide ion migration, and the resulting phase separation and interfacial chemical corrosion. It breaks through the limitation of conventional passivation strategies that can only inhibit the migration of a single type of defect or a single species, and truly achieves multiple stabilizations.

[0019] (2) This invention discloses a supramolecularly optimized flexible perovskite solar cell fabricated in an air environment, which achieves a photoelectric conversion efficiency of 22.43% and exhibits a small hysteresis effect. (DMP5 cavity for FA) + The selective inclusion effect stabilizes the nuclei of photoactive α-phase perovskite in the early stages of crystallization, increasing the driving force for the phase transition from δ-phase to α-phase, thereby significantly suppressing the formation of non-photoactive yellow phase. Based on its rigid macrocyclic structure, DMP5 provides mechanical protection distinct from flexible long-chain polymers during repeated bending. When bending stress causes slight changes in grain boundary spacing, guest cations encapsulated within the cavity can adaptively glide through a reversible host-guest dynamic dissociation-recombination mechanism, achieving adaptive stress release at the molecular scale. After stress relief, the inclusion state spontaneously recovers. Its unencapsulated device, after 1000 bending cycles at room temperature with a 5 mm bending radius, still maintains a normalized photoelectric conversion efficiency of 79.48% of its initial value. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This describes the fabrication process of the flexible perovskite solar cell in Example 1 of the present invention. Supramolecular DMP5 is introduced into the perovskite thin film as a modifier via antisolvent engineering. Due to its large cavity and multiple active sites, it can play a good synergistic defect passivation role. On the one hand, DMP5 interacts with insufficiently coordinated Pb... 2+ On the one hand, it forms a coordinate bond with FA; on the other hand, it forms a coordinate bond with FA. + Hydrogen bonds are established between them. This dual effect helps reduce non-radiative recombination in the perovskite layer, thereby improving the optoelectronic performance and stability of the device.

[0021] Figure 2The current density-voltage (JV) test curves (including forward and reverse scans) of the flexible perovskite solar cells of Examples 1-3 and Comparative Example 1 are shown. The PCE of the device modified with DMP5 reached 22.43%, a significant improvement compared to 20.03% of the device in Comparative Example 1. Furthermore, its open-circuit voltage (Voc) was 1.13 V, and its short-circuit current (Jsc) was 25.092 mA / cm². 2 With a fill factor (FF) of 79.11% and a hysteresis index of 0.013, these key parameters simultaneously demonstrate the excellent improvement effect of DMP5 on flexible batteries.

[0022] Figure 3 The diagram shows the water contact angles of the perovskite films in Example 1 and Comparative Example 1 of this invention. The contact angle of the perovskite layer in Comparative Example 1 is 65°, while that in Example 1 is increased to 89°. This is because during spin coating, DMP5 competes with perovskite ions for reaction, delaying crystallization and inducing oriented growth. Due to its hydrophobicity, large-sized DMP5 molecules accumulate on the surface and at grain boundaries of the final polycrystalline film. These accumulated molecules form a stable supramolecular network on the surface through interactions such as hydrogen bonds and non-covalent forces such as π-π stacking. This densely assembled DMP5 layer acts as a hydrophobic protective film on the perovskite surface, physically isolating water molecules from direct contact with the perovskite.

[0023] Figure 4 These are scanning electron microscope (SEM) images of the perovskite thin films of Example 1 and Comparative Example 1 of the present invention. The perovskite thin film of Comparative Example 1 has smaller grains, more grain boundaries, and a small number of pinhole defects on its surface; after modification with DMP5, the grain size increases and the number of grain boundaries decreases. Figure 4 Cross-sectional views of the perovskite films in Comparative Example 1 and Example 1 can be seen in sections c and d. The DMP5-modified film exhibits larger grain sizes and a tendency for grain growth towards the vertical direction, consistent with the results observed in the top view. The smoother film surface improves interfacial contact with the upper and lower charge transport layers, reduces interfacial resistance, and promotes carrier extraction, thereby enhancing the device's flyback effect (FF) and power conversion efficiency (PCE).

[0024] Figure 5The steady-state photoluminescence (PL) spectra of the perovskite thin films of Example 1 and Comparative Example 1 of this invention are shown. After DMP5 modification, the PL emission intensity of the film was significantly enhanced compared to Comparative Example 1, with a substantial increase in overall emission intensity. This trend indicates that DMP5 modification reduces the defect state density of the perovskite thin film and suppresses nonradiative recombination. The PL peak positions of both samples are located around ~800 nm, corresponding to the intrinsic band-edge emission of perovskite, indicating that DMP5 modification does not change the intrinsic phase structure of perovskite, but only has a passivating effect on surface defects. This result confirms the passivation effect of DMP5 on perovskite defects, providing carrier dynamics evidence for improving the optoelectronic performance of the device.

[0025] Figure 6 The X-ray photoelectron spectroscopy (XPS) of the perovskite films of Example 1 and Comparative Example 1 of this invention shows that the intensity of the Pb 4f peak in the DMP5-modified sample decreases and shifts towards lower binding energy, which can be attributed to the intramolecular groups moving towards uncoordinated Pb. 2+ Donating electrons to form coordinate bonds, thereby passivating Pb 2+ Defects. Furthermore, the characteristic peak of I 3d shifts synchronously to lower binding energies, suggesting that this coordination effect is manifested through Pb-I bonds and modulates the Pb-I bonding framework.

[0026] Figure 7 The images show the normalized power conversion efficiency and physical models of flexible perovskite solar cells in Embodiment 1 and Comparative Example 1 of the present invention under extreme multi-factor environments. Figure 7 In Example a, Example 1 was placed in dark conditions with an ambient relative humidity of 85%. After 1000 hours, its PCE still maintained 84.3% of the initial value. In Comparative Example 1, however, only 34.7% remained. Figure 7 In the continuous illumination stability test of 300 h, Example 1 maintained 50.9% of the initial PCE, which is much higher than the 13.8% of Comparative Example 1. Figure 7 In the case of example c, the thermal stability test also showed significant differences. After storage at 85 °C in the dark for 400 h, Example 1 retained 75.7% of the initial efficiency, while Comparative Example 1 decreased to 37.5%. Figure 7 In Example 1, the DMP5-modified device retained 79.48% of its initial efficiency after 1000 repeated bends at room temperature with a bending radius of 5 mm, significantly higher than the 28.95% efficiency retention of Comparative Example 1. The improved stability in Example 1 is mainly attributed to the electron-rich hydrophobic cavity, multi-site synergistic anchoring passivation, stable α-phase nuclei, and self-healing functions within the DMP5.

[0027] Figure 8The graphs show the reverse scan JV test results for the flexible perovskite solar cells of Comparative Examples 2 and 3. It is clear that the photoelectric performance of these two devices is superior to that of Comparative Example 1, but not as good as that of Example 1. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0029] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0030] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0031] Unless otherwise specified, all raw materials used in the embodiments and comparative examples of this invention are commercially available. See Table 1 for details.

[0032] Table 1. Raw materials used in the embodiments and comparative examples of the present invention.

[0033] Example 1 The device structure of a high-quality perovskite thin-film flexible solar cell provided by this invention is as follows: PET / ITO / SnO2 / FA 0.93 MA 0.07 Pb(I 0.93 Cl 0.07 )3 / Spiro-OMeTAD / Ag.

[0034] The anode is ITO, the electron transport layer is SnO2, and the perovskite photoactive layer is FA. 0.93 MA 0.07 Pb(I 0.93 Cl 0.07 3. The hole transport layer is Spiro-OMeTAD, and the cathode is Ag.

[0035] This invention provides a high-quality perovskite thin film and a method for preparing its solar cell: (1) The SnO2 aqueous colloidal dispersion with an original concentration of 15 wt.% was diluted with deionized water to 3.5 wt.% and used as a precursor solution for the electron transport layer. The SnO2 precursor solution was obtained after stirring at 300 rpm and room temperature for 2.5 hours.

[0036] (2) Lead iodide (PbI2), formamidine iodide (FAI), and methylamine chloride (MACl) were dissolved together in a molar ratio of 1:0.85:0.15 in a mixed solvent of 0.6 ml DMF and 78 μl DMSO as a perovskite precursor solution. The concentration of lead iodide was 1M. The solution was then heated at 65 °C and stirred at 300 rpm for 2 hours before use.

[0037] (3) Dissolve 0.5 mg of DMP5 in 1 ml of CB as the modified antisolvent.

[0038] (4) Dissolve 80 mg of Spiro-OMeTAD powder in 1 ml of chlorobenzene solvent, and add the following common additives: 70 μl of LiTFSI solution (150 mg / ml dissolved in acetonitrile), 20 μl of tBP, and 50 μl of FK 209 solution (170 mg / ml dissolved in acetonitrile). Then stir thoroughly at 400 rpm at room temperature for 2 hours before use.

[0039] (5) The ITO-etched PET substrate was ultrasonically treated with acetone and ethanol for 25 minutes respectively. After being thoroughly dried on a heating table at 100°C, the substrate was treated with ultraviolet (UV) ozone for 25 minutes.

[0040] (7) Add SnO2 solution (volume 140 μL / cm) 2 Spin-coating was performed on a clean substrate at 3500 rpm for 30 seconds. After heat annealing at 155 °C for 35 minutes, the substrate was placed in a UV environment for 15 minutes to obtain a dense electron transport layer.

[0041] (8) Add the perovskite precursor solution (volume 170 μL / cm) 2 The perovskite precursor solution was spin-coated onto a dense SnO2 layer. The spin-coating process lasted 35 seconds and was divided into two segments. The first segment lasted 20 seconds, during which the rotation speed increased from rest to 1800 rpm at an acceleration of 300 rpm / s and was maintained until the end of the first segment. The second segment lasted 15 seconds without interruption, during which the rotation speed increased from 1800 rpm to 3800 rpm at an acceleration of 500 rpm / s and was maintained until the end of the second segment. The DMP5-modified CB prepared in step (3) was used as the antisolvent (at a rate of 510 μL / cm). 2The perovskite film was added approximately 5 seconds before the end of the spin coating process to assist its crystallization. Afterwards, a heat annealing treatment at 155 °C for 35 minutes was performed to aid perovskite crystal growth, resulting in the high-quality target perovskite film described above.

[0042] (9) In order to prepare a complete flexible perovskite solar cell, a Spiro-OMeTAD solution (at a concentration of 200 μL / cm³) was used as the hole transport layer. 2 Spin-coating was performed at 3500 rpm for 30 seconds onto the perovskite layer. To ensure adequate oxidation after deposition, the substrate was placed in a desiccator overnight before depositing the counter electrode.

[0043] (10) A thickness of approximately 60 nm was deposited on top of the Spiro-OMeTAD via vacuum thermal evaporation, with an effective area of ​​0.1 cm². 2 The metal silver is used as the counter electrode. The overall flexible perovskite solar cell device structure is: PET / ITO / SnO2 / FA. 0.93 MA 0.07 Pb(I 0.93 Cl 0.07 )3 / Spiro-OMeTAD / Ag.

[0044] The method for preparing a high-quality perovskite thin film and its solar cell according to the present invention, except for the final step of vacuum evaporation of silver electrode, is carried out in an air environment with a relative humidity of 25~75% and a temperature of 25~40 ℃. Example 2

[0045] The difference from Example 1 is that in step (3), DMP5 is used as a modifier for the CB antisolvent at a concentration of 0.1 mg / ml. Example 3

[0046] The difference from Example 1 is that in step (3), DMP5 is used as a modifier for the CB antisolvent at a concentration of 1.0 mg / ml.

[0047] Comparative Example 1

[0048] The difference from Example 1 is that in step (3), DMP5 is not used as a modifier for the antisolvent of CB, and only pure CB is used as the antisolvent.

[0049] Comparative Example 2

[0050] The difference from Example 1 is that in step (3), DMP5 is replaced with calix[4] aromatics.

[0051] Comparative Example 3

[0052] The difference from Example 1 is that in step (3), DMP5 is replaced with α-cyclodextrin.

[0053] Figure 1 The following is the fabrication process of the flexible perovskite solar cell of Example 1 of the present invention.

[0054] Figure 2 The JV curves of the flexible perovskite solar cells of Examples 1-3 and Comparative Example 1 under forward and reverse scanning are shown in Table 2. The corresponding photovoltaic parameters are listed in Table 2. It can be seen that the photoelectric performance of the cells of Examples 1-3 is significantly better than that of Comparative Example 1, mainly because the appropriate introduction of DMP5 can significantly improve the PCE of the cell. Among them, Example 1 has the best performance. Compared with Comparative Example 1, its short-circuit current (Jsc), open-circuit voltage (Voc), fill factor (FF), and PCE are all significantly improved, while the hysteresis index is significantly reduced.

[0055] Table 2 shows the main performance parameters of the solar cells prepared in Examples 1-3 and Comparative Example 1.

[0056] Subsequently, Example 1, which has the best device performance, will be compared separately with Comparative Example 1.

[0057] Figure 3 The diagram shows the water contact angle of the perovskite thin film in Example 1 and Comparative Example 1.

[0058] Figure 4 SEM images of the perovskite films of Example 1 and Comparative Example 1.

[0059] Figure 5 The PL spectra are for the perovskite films of Example 1 and Comparative Example 1.

[0060] Figure 6 XPS images of the perovskite films of Example 1 and Comparative Example 1.

[0061] Figure 7 This is a comparison graph of the stability of Example 1 and Comparative Example 1 in terms of multi-factor stability.

[0062] Figure 8 The JV test curves of the flexible perovskite solar cells in Comparative Examples 2 and 3 under reverse scanning are shown in Table 3. The corresponding photovoltaic parameters are detailed in Table 3. Compared with Example 1, the Jsc and PCE of Comparative Examples 2 and 3 both show a significant decrease.

[0063] Table 3 shows the main performance parameters of the perovskite solar cells prepared based on Comparative Examples 2 and 3.

[0064] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for preparing multi-stable perovskite thin films based on supramolecular modified antisolvents, characterized in that: The perovskite thin film is obtained by spin-coating a perovskite precursor solution onto a charge transport layer using a one-step antisolvent method, and during this process, an antisolvent containing a supramolecular modifier is rapidly dropped from above the film, followed by a thermal annealing process. The perovskite precursor solution comprises a solute and a solvent. The solute is one or more of the following: methylammonium chloride, methylammonium bromide, lead chloride, lead thiocyanate, lead iodide, lead bromide, lead acetate, stannous iodide, stannous bromide, cesium iodide, cesium bromide, rubidium iodide, methylammonium iodide, methylammonium bromide, methylammonium iodide, n-butylamine iodide, and methylammonium chloride. The solvent is N,N-dimethylformamide, N-methyl-2-pyrrolidone, or an ionic liquid. One or more of dimethyl sulfoxide and γ-butyrolactone; the antisolvent is one or more of chlorobenzene, isopropanol, tert-butanol, ethyl acetate, toluene, and diethyl ether; the supramolecular modifier is one or more of dimethoxyl[5]arene (DMP5), calix[4]arene, calix[5]arene, calix[6]arene, calix[8]arene, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, crown ether, cucurbita, cyclosporine, calixpyrrole, and cyclic peptide.

2. The preparation method according to claim 1, characterized in that: The concentration of the supramolecular modifier in the antisolvent is 0.01–15.0 mg / ml; the supramolecular modifier and the antisolvent are mixed and heated at 20–45 °C and stirred at 200–450 rpm for 0.5–2.5 h.

3. The preparation method according to claim 1, characterized in that: The method for preparing the perovskite precursor solution includes mixing the solute and solvent, heating at 40–80 °C, and stirring at 200–450 rpm for 0.5–3.5 h.

4. The preparation method according to claim 1, characterized in that: The spin coating step lasts for 10-35 seconds and is divided into two segments. The first segment lasts for 3-18 seconds, during which the rotation speed increases from a standstill to 1800 rpm at an acceleration of 200-450 rpm / s and is maintained until the end of the first segment. The second segment lasts for 7-17 seconds without interruption, during which the rotation speed increases from 1800 rpm to 3800 rpm at an acceleration of 300-800 rpm / s and is maintained until the end of the second segment.

5. The preparation method according to claim 1, characterized in that: The annealing temperature is 90~170 ℃, and the time is 5~55 min.

6. The preparation method according to claim 1, characterized in that: The volume ratio of the antisolvent to the perovskite precursor solution is 6~66:

6.

7. A multi-stable perovskite thin film prepared by the preparation method according to any one of claims 1 to 6.

8. The perovskite thin film as described in claim 7, characterized in that: The thickness of the multi-stabilized perovskite film is 300~800 nm; the relative humidity of the air environment during the preparation of the perovskite film is 25~75%, and the temperature is 25~40 ℃.

9. The application of the multi-stabilized perovskite thin film as described in claim 8 in flexible perovskite solar cells.

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