Laser shock annealing preparation method of quasi-two-dimensional perovskite thin film, thin film and solar cell

Abstract

The invention discloses a laser shock annealing preparation method of a quasi-two-dimensional perovskite thin film, the thin film and a solar cell thereof, and belongs to the field of photoelectric device manufacturing. According to the method, under the environmental condition, five-pulse laser acts on a perovskite precursor wet film covered with a transparent limiting layer, and crystallization is induced through the synergistic effect of laser-induced transient heat and shock wave pressure. According to the method, the microstructure of the thin film is optimized by forming a stable intermediate phase, constructing a uniform stress field and accurately regulating and controlling crystallization kinetics, and particularly, grain growth is promoted, defects are reduced, and organic-inorganic interaction is enhanced. The prepared thin film is high in crystallization quality and low in defect density. The solar cell prepared by using the material as a light absorption layer can effectively inhibit non-radiative recombination and optimize carrier transport, thereby synchronously realizing high power conversion efficiency and excellent long-term working stability.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic device manufacturing technology, specifically relating to a laser shock annealing method for preparing a quasi-two-dimensional perovskite thin film, the quasi-two-dimensional perovskite thin film obtained therefrom, and a solar cell containing the thin film as a light-absorbing layer. Background Technology

[0002] Metal halide perovskite solar cells (PSCs) have become a research frontier due to their excellent power conversion efficiency (PCE). Among them, the quasi-two-dimensional (Q-2D) perovskite structure formed by introducing bulk organic cations exhibits superior environmental stability. However, the performance of Q-2D perovskites still lags significantly behind that of three-dimensional (3D) perovskites, mainly due to two major bottlenecks: first, the charge transport efficiency of spacer cations in Q-2D perovskites is much lower than that inside the crystal; second, the micro- and nano-structures of the thin film (such as grain size, orientation, and defect density) are difficult to control precisely in solution processing, as they are determined by crystallization kinetics. Traditional thermal annealing (TA) processes, due to their slow and uniform thermal field, easily lead to perovskite decomposition, non-perovskite phase residues, and random grain orientation, thereby introducing a large number of non-radiative recombination defects, which severely restrict the PCE and long-term operational stability of PSCs.

[0003] To overcome the limitations of thermal annealing (TA), researchers have explored rapid annealing strategies, such as ultrafast laser annealing (LA). Lasers can provide instantaneous, localized, and controllable energy input, rapidly bridging the temperature window of perovskite decomposition and optimizing the micro / nanostructure of perovskite films. However, existing LA techniques primarily utilize the photothermal effect of lasers, and their energy transfer and interaction mechanisms remain relatively simple. Current research lacks a deep understanding and effective utilization strategies regarding the synergistic ultrafast mechanical effects generated during the interaction between laser and materials, and their precise control mechanisms and potential value in crystallization kinetics and crystal structure. Therefore, existing LA techniques have failed to achieve synergistic control of the thermo-mechanical coupling effect during the crystallization process of perovskite films, limiting their ability to further optimize the micro / nanostructure of films and improve carrier transport efficiency.

[0004] Therefore, developing a new method that can effectively synergistically utilize laser-induced shock wave pressure and thermal effects to precisely control the crystallization dynamics of Q-2D perovskites, thereby optimizing the microstructure of thin films, the optoelectronic properties of devices, and their stability, is a key technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention aims to overcome the aforementioned shortcomings of existing technologies and provide a laser shock annealing (LSA) preparation method for Q-2D perovskite that enables precise control of crystallization kinetics. This method utilizes the synergistic effect of laser-induced instantaneous thermal effects and shock wave pressure to achieve precise control over the nucleation and growth processes, thereby obtaining high-quality thin films. This invention also provides Q-2D perovskite thin films with excellent structure and performance prepared by this method, as well as high-efficiency, high-stability solar cells based on these films.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a method for preparing a light-sensitive autoclave (LSA) of a Q-2D perovskite thin film, characterized by comprising the following steps: S1: Provides Q-2D perovskite precursor wet film; S2: Cover the surface of the wet film with a transparent confinement layer; S3: A pulsed laser beam is used to impact the wet film through the transparent confinement layer. The transient thermal effect induced by the laser and the shock wave pressure work together to induce perovskite crystallization and form a thin film. The impact treatment induces the precursor to form a stable intermediate phase, thereby regulating the crystallization kinetics.

[0007] Preferably, the shock wave pressure is between 0.1 GPa and 9 GPa; the wavelength range of the pulsed laser is 1064 nm, and the single-pulse energy density is 45 J / cm². 2 Up to 60 J / cm 2 The pulse width is 10 ns.

[0008] Preferably, the shock treatment induces the precursor to form a stable lead iodide (PbI2)-based intermediate phase, which has characteristic absorption in the ultraviolet-visible absorption spectrum (UV-Vis) at wavelengths from 740 nm to 760 nm.

[0009] Preferably, the impact treatment creates a uniform stress field inside the film, and the attenuation rate of the stress field is less than 5% in the 500 nm thickness range.

[0010] Preferably, the perovskite in the Q-2D perovskite precursor wet film has the chemical formula (PEA)2MA4Pb5I. 16 PEA stands for phenylethylammonium ion, and MA stands for methylammonium ion.

[0011] Preferably, the method is performed under environmental conditions.

[0012] In a second aspect, the present invention provides a Q-2D perovskite thin film, characterized in that it is prepared by the preparation method described in any one of the first aspects above; The X-ray diffraction (XRD) intensity ratio of the (111) crystal plane to the (202) crystal plane of the thin film is less than 0.45; Based on density functional theory (DFT) calculations, the net dipole moment of the organic cation PEA in the film is no greater than 3.5 D; The Williamson-Hall strain constant of the thin film is no greater than 0.7.

[0013] Preferably, the Young's modulus of the film is not less than 25 GPa.

[0014] Preferably, the trap state density of the thin film is not higher than 9.12 × 10⁻⁶. 15 cm -3 And the carrier mobility is not less than 10.80×10 -4 cm 2 ·V -1 ·s -1 ...

[0015] Thirdly, the present invention provides a solar cell comprising a perovskite light-absorbing layer, characterized in that the perovskite light-absorbing layer is a Q-2D perovskite thin film as described in any one of the second aspects above.

[0016] Preferably, the photoelectric conversion efficiency of the solar cell under standard test conditions is not less than 19%.

[0017] Preferably, the solar cell performs maximum power point tracking at 85°C / 85% relative humidity, and its efficiency remains at no less than 80% of the initial value after 800 hours.

[0018] The beneficial effects of this invention are: 1. Precise cross-scale control of crystallization kinetics. Through the synergistic effect of transient high temperatures (peak value approximately 3430 K) induced by pulsed lasers and high peak pressures (e.g., 8.91 GPa), precise control over perovskite nucleation and growth kinetics was achieved. This process increased the crystallization rate by approximately 11 orders of magnitude (compared to TA) and drove the formation of a stable PbI2-based mesophase with characteristic absorption (approximately 750 nm), thereby inducing a faster and more ordered crystallization pathway.

[0019] 2. Synergistic optimization of film microstructure and stress distribution. LSA constructs a highly uniform stress field inside the film (attenuation in the thickness direction <5%), under which the film microstructure is comprehensively improved: the grain size is significantly increased (e.g. from 50-160 nm in TA to 210-260 nm), the preferred orientation of the (202) crystal plane is enhanced (the (111) / (202) intensity ratio is optimized from 0.3 to 0.41), the organic cations are arranged in a highly ordered manner (the net dipole moment of PEA is reduced from 3.8 D to 3.4 D), and the formation of PbI2 phase is effectively suppressed.

[0020] 3. Simultaneous improvement in optoelectronic and mechanical properties. Compared to TA films, the defect density of perovskite films prepared by LSA is reduced from 2.8 × 10⁻⁶. 16 Reduced to 9.12×10 15 cm -3 The carrier lifetime was extended to 7.49 ns, and the carrier mobility reached 10.80 × 10⁻⁶. -4 cm 2 V -1 s -1 Meanwhile, the Young's modulus increased to 28.38 GPa, and the hardness also increased from 0.48 GPa to 0.56 GPa. This means that the film possesses both superior charge transport capability and stronger mechanical stability.

[0021] 4. Breakthroughs in both device efficiency and long-term stability. Based on the aforementioned high-quality thin films, PSCs have achieved a comprehensive leap in performance: the champion device's PCE has increased to 20.41%, with improvements across all parameters. More importantly, under the stringent accelerated aging conditions of 85℃ / 85% RH, the LSA device still maintains 86.3% of its initial efficiency after 800 hours, far exceeding the TA device (49.6%). Its superior stability stems from the enhanced inorganic-organic interactions and higher thermal decomposition activation energy.

[0022] 5. The process is simple and environmentally friendly, and has the potential for industrialization. The entire LSA process can be completed under ambient conditions, without the need for glove boxes or complex atmosphere control. The process is simple and highly repeatable. The thermo-mechanical effects can be flexibly controlled by precisely adjusting the laser parameters, providing a reliable and promising technical solution for the large-scale preparation of high-quality perovskite thin films. Attached Figure Description

[0023] Figure 1 This is a diagram illustrating the crystallization kinetics of Q-2D perovskite involved in an embodiment of the present invention.

[0024] in, Figure 1 a is the in-situ UV-Vis image of the Q-2D perovskite film, showing the formation of the intermediate phase during TA and LSA treatment; Figure 1 b is a comparison diagram of the crystallization growth process of Q-2D perovskite on SnO2 / ITO / glass substrate obtained by molecular dynamics simulation (MD); Figure 1 c and Figure 1 d is a graph showing the relationship between the laser center temperature and time and distance during the LSA process, obtained through multiphysics simulation. Figure 1 e and Figure 1 f is a graph showing the relationship between laser shock pressure on the Q-2D perovskite surface and time and distance during LSA. Unless otherwise specified, LSA in the figure description specifically refers to a laser power density of 54 J / cm². 2 .

[0025] Figure 2 This is a micro / nano structure diagram of the Q-2D perovskite thin film in an embodiment of the present invention.

[0026] in, Figure 2 a shows the stress-time relationship and stress distribution cloud map at the center of the perovskite crystal under the action of single-pulse or continuous-pulse laser (inset). Figure 2 b represents the relationship between the grain boundary stress of Q-2D perovskite and time and distance; the attached figure shows the stress distribution diagram. Figure 2 c and Figure 2 d represents the confocal laser scanning microscopy (CLSM) image of Q-2D perovskite obtained by TA and LSA processing, and the corresponding grain size statistical distribution diagram of scanning electron microscopy (SEM). Figure 2 e shows a comparison of the X-ray diffraction (XRD) patterns of TA and LSA thin films; Figure 2 f represents the electrostatic potential and dipole moment of the PEA cation obtained through DFT simulation and the corresponding Pb-I-Pb bond angle measured experimentally.

[0027] Figure 3 This is a diagram showing the performance and photophysical process analysis of Q-2D PSCs in an embodiment of the present invention.

[0028] in, Figure 3 a represents the photocurrent density-voltage curve of PSCs; Figure 3 b represents the external quantum efficiency and integral current density curves of PSCs; Figure 3 c is the open circuit voltage. V OC The relationship between light intensity and light intensity; Figure 3d represents the carrier lifetime measured by time-resolved photoluminescence (TRPL); Figure 3 e represents the space-charge-limited current (SCLC) curve of a single-carrier device; Figure 3 f represents the current density-voltage characteristic of Q-2D PSCs in the dark state; Figure 3 g is a graph showing the relationship between frequency and the negative logarithm of the imaginary part of impedance; Figure 3 h is a graph showing the relationship between frequency and capacitance; Figure 3 i is the Nyquist plot of TA and LSA Q-2D PSCs.

[0029] Figure 4 This is a diagram showing the stability and ion interaction analysis of Q-2D perovskite and its solar cells in the embodiments of the present invention.

[0030] in, Figure 4 a represents the stability curve of PSCs tracking at maximum power point (MPP) under 1 solar irradiance in an atmospheric environment with 85% relative humidity and 85℃. Figure 4 b is the heating curve of Q-2D perovskite at a heating rate of 10 K / min using differential scanning calorimetry (DSC). Figure 4 c is the fusion thermal analysis diagram of Q-2D perovskite obtained by the Kissinger method; Figure 4 d is a graph showing the C / N ratio changing over time, obtained by X-ray photoelectron spectroscopy (XPS) (the test temperature is higher than the perovskite decomposition temperature). Figure 4 e represents the binding energy of Pb 4f on the perovskite film surface; Figure 4 f represents the Fourier Transform Infrared Spectroscopy (FTIR) spectrum of the perovskite thin film. Figure 4 g represents the Young's modulus and hardness obtained through nanoindentation.

[0031] Figure 5 These are morphological comparison images of Q-2D perovskite films treated with different laser energy densities in embodiments of the present invention.

[0032] in, Figure 5 a is at 45 J / cm 2 CLSM images of thin films obtained by LSA processing at energy density; Figure 5 b is at 54J / cm2 CLSM images of thin films obtained by LSA processing at energy density; Figure 5 c is at 60 J / cm 2 CLSM image of the thin film obtained by LSA processing at energy density.

[0033] Figure 6 The image shows the light absorption and photoluminescence spectra of the Q-2D perovskite thin film in this embodiment of the invention.

[0034] in, Figure 6 a is a comparison of the absorption spectra of TA and LSA films with the band gaps determined by the Tauc diagram; Figure 6 b represents different laser energy densities (45, 54, 60 J / cm²). 2 Comparison of absorption spectra of LSA thin films under different conditions; Figure 6 c is a comparison diagram of the Urbach energies of TA and LSA films; Figure 6 d is a comparison of the Urbach energies of LSA films under different laser energy densities; Figure 6 e is a comparison of the steady-state photoluminescence (PL) spectra of TA and LSA films; Figure 6 f is a comparison of the steady-state PL spectra of LSA films under different laser energy densities. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of this invention.

[0036] Unless otherwise specified, all materials, reagents, and instruments used in the following examples are commercially available. Experimental methods not specifically described in the examples are generally performed under conventional conditions in the art or as recommended by the manufacturer.

[0037] Example 1: Fabrication and Performance Comparison of Q-2D Perovskite Solar Cells This embodiment details the process of preparing quasi-Q-2D perovskite thin films and solar cells using both conventional TA and the LSA method of this invention, and compares their performance.

[0038] 1. Materials Fluorine-doped tin oxide (FTO) conductive glass (sheet resistance: 12 Ω / sq, transmittance: 90%), lead iodide (PbI2, purity 99.999%), phenylethylammonium iodide (PEAI, purity >99%), methylammonium iodide (MAI), hole transport material 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD, purity 99.5%), dopants lithium bis(trifluoromethanesulfonyl)imide (LiTFSI, purity 99%) and 4-tert-butylpyridine (tBP, purity 96%) were all purchased from relevant commercial suppliers. The electron transport layer material, tin dioxide (SnO2) colloidal dispersion (concentration 15 wt%, solvent: water), was purchased from Alfa Aesar.

[0039] The solvents used included N,N-dimethylformamide (DMF, 99.9% purity), dimethyl sulfoxide (DMSO, 99.9% purity), acetonitrile (Acetonitrile, 99.9% purity), chlorobenzene (CB, 99.5% purity), and ethyl acetate (EA, 99% purity), purchased from Sigma-Aldrich and Adamas.

[0040] 2. Preparation of Q-2D perovskite precursor solution Weigh out the appropriate masses of MAI, PbI2, and PEAI according to a molar ratio of 1:2:5. Dissolve the weighed precursors in a mixed solvent of DMF and DMSO to prepare a 1.7 mol / L Q-2D perovskite precursor solution, wherein the volume ratio of the mixed solvent is DMF:DMSO = 4:1. Stir the prepared solution magnetically at room temperature until it is completely clear and transparent, and set aside for later use.

[0041] 3. Substrate cleaning and electron transport layer fabrication The FTO conductive glass was ultrasonically cleaned sequentially with detergent, deionized water, acetone, and isopropanol for 15 minutes each time. After cleaning, it was dried in a 100°C oven for 15 minutes. The SnO2 colloidal dispersion was diluted with deionized water and spin-coated onto a clean FTO substrate, followed by annealing on a preheated hot plate at 150°C for 30 minutes to form a dense electron transport layer (ETL).

[0042] 4. Preparation of perovskite light-absorbing layer (1) Wet film preparation: 30 µL of the above Q-2D perovskite precursor solution was dropped onto an FTO substrate coated with SnO2ETL, and a two-step spin coating method was used to form a film: the first step was spin coating at 1000 rpm for 10 seconds, and the second step was spin coating at 4500 rpm for 25 seconds. 15 seconds before the end of the high-speed spin coating stage, 120 µL of CB was dynamically added as an antisolvent using a pipette. After spin coating, a uniform perovskite precursor wet film was obtained.

[0043] (2) Annealing treatment: Comparative Example (TA): The above wet film was immediately transferred to a hot stage preheated to 100°C and annealed for 10 minutes to allow perovskite to crystallize and form a TA film.

[0044] This invention embodiment (LSA): A high-strength transparent glass sheet is tightly covered on the surface of the wet film as a confinement layer, forming a stacked structure of FTO / ETL / wet film / glass. A 54 J / cm² pressure is used. 2 A pulsed laser was used for scanning (laser parameters: 1064 nm wavelength, single pulse energy 2 J, pulse width 10 ns, repetition rate 10 Hz, scanning speed 40 mm / s, spot diameter approximately 1 mm). Multiphysics simulations verified that these parameters generated a transient temperature peak of approximately 3430 K at the thin film, and a shock wave with a peak pressure of approximately 8.91 GPa within approximately 20 ns. The attenuation of this shock wave along the film thickness (approximately 500 nm) was less than 5%, forming a uniform stress field. This treatment induced the rapid formation of a stable intermediate phase with characteristic absorption at ~750 nm in the precursor, further inducing rapid crystallization of perovskite within a timescale of hundreds of nanoseconds to microseconds, forming an LSA thin film.

[0045] 5. Hole transport layer and electrode fabrication The prepared Spiro-OMeTAD solution was spin-coated as a hole transport layer onto the perovskite film cooled to room temperature at 3000 rpm for 30 seconds. Finally, a silver electrode of approximately 100 nm thickness was deposited on the top electrode region in a vacuum thermal evaporation coating machine to complete the fabrication of the solar cell device.

[0046] 6. Performance Characterization Results of Thin Films and Devices A series of characterizations were performed on TA and LSA thin films and devices. Key data comparisons are as follows: Table 1: Comparison of properties of Q-2D perovskite thin films prepared by TA and LSA Table 2: Comparison of photovoltaic performance of Q-2D PSCs based on TA and LSA thin films Results analysis: 1. Structural optimization: LSA treatment significantly increased the grain size through a thermo-mechanical synergistic effect, induced the preferred growth of the (202) crystal plane, eliminated PbI2 impurities, and made the organic cations more orderly arranged (reduced dipole moment). These all confirm the effective control of crystallization kinetics and film microstructure of this invention.

[0047] 2. Performance Improvement: Structural optimization directly leads to improved intrinsic quality of the thin film: reduced defects, extended carrier lifetime, and increased mechanical strength. This is reflected in the device as follows: V OC , J SC , FF The overall improvement resulted in a PCE increase of over 20%.

[0048] 3. Breakthrough in stability: The enhanced inorganic-organic interaction and higher lattice integrity of the LSA thin film increase its thermal decomposition activation energy, thereby exhibiting stability far exceeding that of TA devices in accelerated aging tests, proving the effectiveness of this invention in solving the problem of perovskite stability.

[0049] Example 2: Effect of laser energy density This embodiment aims to illustrate that laser energy density (which directly affects shock wave pressure) is a key parameter for controlling thin film performance.

[0050] Keeping other parameters such as laser wavelength (1064 nm), pulse width (10 ns), and scanning speed (40 mm / s) constant, only the single-pulse energy was changed, thereby altering the energy density acting on the thin film. Thin films with energy densities of 40 J / cm² were prepared. 2 54J / cm 2 (Same as Example 1) and 65 J / cm 2 LSA thin films and devices.

[0051] Characterization revealed that when the energy density is between 45 and 60 J / cm³, 2Within the specified range, the film exhibits high crystallinity, with large and uniform grain size, including 54 J / cm. 2 For optimal conditions. When the energy density is too low (40 J / cm³), 2 When the shock wave pressure is insufficient, crystallization is incomplete, and the film has pores; when the energy density is too high (65 J / cm³), the film is porous. 2 Excessive thermal-mechanical effects may lead to localized damage or peeling of the film. This indicates the existence of an optimized process window, defined in the claims as 45-60 J / cm. 2 The range covers the optimization interval.

[0052] Simulation and Mechanism Evidence To gain a deeper understanding of the mechanism of action of LSA, multiphysics coupling simulations and molecular dynamics simulations were performed.

[0053] 1. Multiphysics simulation: The transient temperature and pressure field evolution under laser action was reproduced, and the generation of GPa-level shock wave pressure within 100 nanoseconds and its uniformity (attenuation <5%) in the film thickness direction were confirmed, providing a theoretical basis for the pressure range and stress field uniformity in the claims.

[0054] 2. Molecular dynamics simulations: The crystallization process under TA and LSA conditions was compared, and it was shown that LSA accelerated the crystallization time from hundreds of seconds to the microsecond level, and revealed the key role of the stable meso phase in guiding rapid and ordered crystallization.

[0055] 3. First-principles calculations: The electronic structure of perovskite under different stress states was calculated, confirming the pressure-induced increase in Pb-I-Pb bond angle and band gap change, explaining part of the reason for the performance improvement from the perspective of electronic structure.

[0056] In summary, the above embodiments fully demonstrate and verify the technical effects of the laser shock annealing method described in this invention. Those skilled in the art will understand that changes can be made to laser parameters (such as wavelength, pulse number, and scanning mode), confinement layer material, precursor components, and solvent system without departing from the principles and spirit of this invention; such changes should also be considered to fall within the protection scope of this invention.

Claims

1. A method for preparing quasi-two-dimensional perovskite thin films by laser shock annealing, characterized in that, Includes the following steps: S1: Provides a quasi-two-dimensional perovskite precursor wet film; S2: Cover the surface of the wet film with a transparent confinement layer; S3: A pulsed laser beam is used to impact the wet film through the transparent confinement layer. The transient thermal effect induced by the laser and the shock wave pressure work together to induce perovskite crystallization and form a thin film. The impact treatment induces the precursor to form a stable intermediate phase, thereby regulating the crystallization kinetics.

2. The preparation method according to claim 1, characterized in that, The shock wave pressure is between 0.1 GPa and 9 GPa; the pulsed laser has a wavelength range of 1064 nm and a single-pulse energy density of 45 J / cm². 2 Up to 60 J / cm 2 The pulse width is 10 ns.

3. The preparation method according to claim 1, characterized in that, The stable intermediate phase exhibits characteristic absorption in the ultraviolet-visible absorption spectrum at wavelengths from 740 nm to 760 nm.

4. The preparation method according to claim 1, characterized in that, The impact treatment creates a uniform stress field inside the film, and the attenuation rate of the stress field is less than 5% in the 500 nm thickness range.

5. The preparation method according to claim 1, characterized in that, The perovskite chemical formula in the quasi-two-dimensional perovskite precursor wet film is (PEA)2MA4Pb5I. 16 PEA stands for phenylethylammonium ion, and MA stands for methylammonium ion.

6. The preparation method according to claim 1, characterized in that, The method is performed under environmental conditions.

7. A quasi-two-dimensional perovskite thin film, characterized in that, Prepared by the preparation method according to any one of claims 1 to 6; The ratio of the X-ray diffraction intensity of the (111) crystal plane to the (202) crystal plane of the thin film is less than 0.45; Based on density functional theory calculations, the net dipole moment of the organic cation PEA in the film is no greater than 3.5 D.

8. The quasi-two-dimensional perovskite thin film according to claim 7, characterized in that, The Williamson-Hall strain constant of the thin film is no greater than 0.

7.

9. The quasi-two-dimensional perovskite thin film according to claim 7, characterized in that, The Young's modulus of the film is not less than 25 GPa.

10. The quasi-two-dimensional perovskite thin film according to claim 7, characterized in that, The density of trapped states in the thin film is no higher than 9.12 × 10⁻⁶. 15 cm -3 And the carrier mobility is not less than 10.80×10 -4 cm 2 ·V -1 ·s -1 .

11. A solar cell comprising a perovskite light-absorbing layer, characterized in that, The perovskite light-absorbing layer is a quasi-two-dimensional perovskite thin film as described in any one of claims 7 to 10.

12. The solar cell according to claim 11, characterized in that, The solar cell has a photoelectric conversion efficiency of no less than 19% under standard test conditions.

13. The solar cell according to claim 11, characterized in that, The solar cell was subjected to maximum power point tracking at 85°C / 85% relative humidity, and its efficiency remained at no less than 80% of the initial value after 800 hours.

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