In-situ crystallization-passivation integrated preparation method of perovskite thin film, perovskite solar cell and preparation method of perovskite solar cell

Abstract

The invention relates to the technical field of photoelectric materials and devices, in particular to an in-situ crystallization-passivation integrated preparation method of a perovskite thin film, a perovskite solar cell and a preparation method of the perovskite solar cell. The method comprises the following steps: coating a perovskite precursor solution on a substrate to form a wet film; immediately purging by using a nitrogen knife to obtain an intermediate-state film; coating a passivation layer solution on the intermediate-state thin film; and finally, carrying out one-time thermal annealing, and synchronously completing final crystallization of perovskite and permeation passivation of the passivating agent in the annealing process. According to the method, the passivation step is preposed, and crystallization and passivation are cooperatively carried out through one-step annealing. According to the method, the process is simplified, the energy consumption is reduced, more importantly, the passivator can actively inhibit the formation of intrinsic defects in the crystal growth process, source passivation is realized, and the bulk phase and interface defect density of the perovskite thin film is remarkably reduced. The perovskite solar cell prepared by the method has higher photoelectric conversion efficiency and excellent stability.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic materials and devices, and in particular to an integrated method for in-situ crystallization and passivation of perovskite thin films, perovskite solar cells and their fabrication methods. Background Technology

[0002] Perovskite solar cells have become a research hotspot in next-generation photovoltaic technology due to their excellent photoelectric performance and potential for large-scale, low-cost manufacturing. The preparation of high-quality perovskite thin films is crucial for obtaining high-performance devices. Traditional large-area perovskite thin film preparation processes (such as blade coating and slot coating) typically include: coating a wet perovskite precursor film, inducing crystallization through anti-solvent treatment or vacuum flash evaporation, performing thermal annealing to form a perovskite crystalline film, subsequently coating a passivation layer solution, and annealing again to activate the passivation layer.

[0003] This traditional step-by-step process has inherent drawbacks: First, the two independent annealing steps result in a cumbersome process flow, high energy consumption, and long production time, which is not conducive to high-speed industrial production. Second, the passivation effect is delayed; the passivation layer is introduced only after the perovskite grains have fully formed, and can only passively repair existing surface and grain boundary defects. It cannot actively suppress the formation of intrinsic defects (such as lead vacancies and iodine vacancies) during crystal growth, which is a "band-aid solution." Finally, the step-by-step process may lead to poor interfacial contact between the perovskite layer and the passivation layer, introducing interfacial stress, which is detrimental to carrier transport.

[0004] To address the aforementioned issues, existing technologies have introduced methods that introduce passivating agent vapor into the perovskite annealing atmosphere (such as CN118695758A) in an attempt to achieve simultaneous crystallization and passivation. However, this method involves heat treatment in an atmosphere filled with passivating agent vapor, making it difficult to precisely control the passivating agent concentration. This can easily lead to over-reaction, forming non-perovskite impurities and damaging the crystal structure and photoelectric properties of the thin film.

[0005] Therefore, there is an urgent need in the field for a novel method for preparing perovskite thin films that can simplify the process and actively suppress the generation of defects from the crystal growth source. Summary of the Invention

[0006] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and provide an integrated in-situ crystallization-passivation preparation method for perovskite thin films, a perovskite solar cell, and a method for preparing the same. This invention's perovskite thin film preparation method optimizes the process sequence by placing the passivation layer before the final crystallization step of the perovskite, achieving simultaneous perovskite crystallization and deep passivation in a single annealing step. This simplifies the process, reduces defect density from the source, improves the quality of the perovskite thin film, and enhances the photoelectric conversion efficiency and stability of the final device.

[0007] The technical solution adopted by this invention to solve its technical problem is: An integrated method for in-situ crystallization and passivation of perovskite thin films, specifically including the following steps: Step S1: Prepare perovskite precursor solution; Step S2: Coat the perovskite precursor solution onto the substrate to form a wet film; Step S3: Within 5 seconds after the wet film coating is completed, the wet film obtained in step S2 is immediately purged with a nitrogen knife to obtain a perovskite intermediate film. Step S4: Coat a passivation layer solution onto the perovskite intermediate film obtained in step S3 to obtain a stacked film; Step S5: Perform a thermal annealing treatment (integrated synergistic annealing) on ​​the laminated film obtained in step S4. During this annealing process, the perovskite intermediate film completes its final crystallization, and at the same time, passivating agent molecules penetrate into the perovskite intermediate film to achieve passivation.

[0008] In the above preparation method, the traditional multi-step annealing is combined into one step, which simplifies the process and reduces energy consumption and time costs; the passivation layer is introduced before final crystallization, so that the passivating agent can penetrate to the growth front and achieve "source passivation"; crystallization and passivation are carried out simultaneously in one-step annealing, which promotes interface fusion and reduces interface defects.

[0009] Furthermore, in step S2, the coating method is spin coating, scraping coating, or slot coating.

[0010] Furthermore, in step S3, the purging temperature of the nitrogen knife is 40–70°C, the gas flow rate is 10–40 L / min, and the purging time is 10–20 seconds. Within this temperature, gas flow, and time range, the nitrogen knife can effectively remove solvent to form a stable intermediate film, avoiding both excessive drying leading to cracking and residual solvent affecting the subsequent passivation layer coating quality, thus providing an ideal interface for "passivation first".

[0011] Furthermore, in step S4, the coating method is slot coating or inkjet printing. Slot coating and inkjet printing can achieve uniform and precise coating of the passivation layer solution. In particular, inkjet printing is suitable for patterned or localized passivation, improving process flexibility and material utilization.

[0012] Furthermore, in step S4, the passivation layer solution includes a passivating agent and a solvent, wherein the passivating agent is selected from at least one of Lewis bases, Lewis acids, and organic ammonium salts; and the solvent is a solvent that does not dissolve the perovskite intermediate film.

[0013] Further, the Lewis base is selected from at least one of ammonium thiocyanate, urea iodide, TPPO (triphenylphosphine oxide), and PMMA (polymethyl methacrylate); the organic ammonium salt is selected from at least one of phenylethyl ammonium iodide, ethylenediamine dihydroiodide, m-fluorophenylethylamine iodide, and butyl ammonium iodide; and the solvent is at least one of isopropanol and ethanol.

[0014] Furthermore, in step S5, the single-stage hot annealing process is as follows: the annealing temperature is 80–150°C, and the annealing time is 10–30 minutes. Within this temperature and time range, the single-stage hot annealing process ensures that the perovskite fully crystallizes while allowing the passivating agent sufficient time to diffuse, penetrate, and combine with the defect sites, achieving deep passivation.

[0015] A method for fabricating a perovskite solar cell specifically includes the following steps: Step a: Clean the conductive substrate; Step b: Prepare the hole transport layer; Step c: Prepare a self-assembled monolayer; Step d: Prepare a perovskite-passivation layer monolithic layer; Step e: Prepare the electron transport layer; Step f: Prepare the electrode layer; In step d, the perovskite-passivation layer is prepared using the above-described method.

[0016] Furthermore, by performing P1 laser scribing on the conductive substrate before step a, performing P2 laser scribing on the battery between steps e and f, and performing P3 laser scribing on the battery after step f, a multi-cell series device can be fabricated.

[0017] In step b, the hole transport layer is prepared using methods such as PVD, spin coating, blade coating, and slot coating. In step c, the self-assembled monolayer is prepared by inkjet printing, blade coating, or slot coating. In step e, the electron transport layer is prepared by methods such as spin coating, blade coating, slot coating, and vapor deposition; In step f, the electrode layer is prepared using methods such as PVD, RPD, and vapor deposition.

[0018] A perovskite solar cell, wherein the perovskite solar cell is prepared by the above-described preparation method.

[0019] This in-situ crystallization-passivation integrated preparation method for perovskite thin films employs a process of perovskite precursor film coating, nitrogen-assisted crystallization, passivation layer solution coating, and integrated synergistic annealing. By omitting the separate annealing step for the perovskite layer and combining two annealing processes into one, this method significantly shortens the process flow, reduces energy consumption and production time, and better meets the needs of industrial production. Furthermore, the core innovation of this invention lies in "passivation first." Simultaneously with the final crystallization of the perovskite, passivating agent molecules can penetrate to the grain boundary growth front under heat treatment, actively participating in and regulating the crystallization process. This not only passivates existing surface defects but also effectively inhibits the formation of intrinsic defects (such as lead vacancies and iodine vacancies) during crystal growth, achieving a "prevention is better than cure" effect, thereby obtaining perovskite grains with lower bulk defect density. Additionally, the intervention of the passivating agent may alter the surface energy of the crystal planes, thereby promoting the longitudinal growth of perovskite grains, increasing grain size, reducing the number of grain boundaries, and further reducing carrier recombination channels. Finally, during the thermal annealing process, the perovskite layer and the passivation layer form a gradient or strongly chemically bonded interface due to the interdiffusion and interaction of molecules, rather than a simple physical contact. This is beneficial for carrier extraction and suppresses interfacial recombination.

[0020] Based on the above advantages, perovskite solar cells prepared using this invention typically exhibit higher open-circuit voltage and fill factor, thus resulting in higher photoelectric conversion efficiency. Simultaneously, due to the significant reduction in bulk and interface defects, the long-term operational stability and resistance to damp heat are also greatly improved.

[0021] The beneficial effects of this invention are as follows: This invention has a reasonable design and a simple preparation method, and has the following advantages: (1) Simplified process and reduced cost: By designing "passivation first" and "one-step annealing", the traditional two annealing processes are combined into one, which significantly shortens the process flow, reduces heat energy consumption and production time, and is more in line with the needs of large-scale, continuous industrial production. (2) Source passivation and defect suppression: The core innovation of this invention is to coat the passivation layer solution onto the intermediate state film that has not yet fully crystallized; in the subsequent integrated annealing process, the passivating agent molecules can diffuse with the solvent to the growth front of the perovskite grains and actively participate in the crystallization process; this can not only repair surface defects, but also effectively suppress the formation of intrinsic point defects (such as lead vacancies and iodine vacancies) from the growth source, achieve the effect of "prevention of disease", and obtain perovskite grains with lower bulk defect density; (3) Improve crystallization and optimize interface: The introduction of passivating agent may regulate the surface energy of crystal facets, promote the longitudinal growth of perovskite grains, increase grain size, and reduce the number of grain boundaries, thereby reducing carrier recombination channels; at the same time, during the hot annealing process, the perovskite layer and the passivation layer form a gradient or strong chemical bond interface through molecular interdiffusion and chemical reaction, rather than a simple physical stacking, which is beneficial for carrier extraction and significantly inhibits interface recombination. (4) Significantly improved performance: Based on the above mechanism, perovskite solar cells prepared by this method usually exhibit higher open-circuit voltage (Voc) and fill factor (FF), thereby achieving higher photoelectric conversion efficiency (PCE); at the same time, due to the significant reduction of bulk and interface defects, the long-term operating stability and resistance to damp heat of the device are also greatly improved. (5) High process tolerance: The examples show that the device can still maintain excellent performance when the nitrogen knife purging parameters are adjusted within a reasonable range, indicating that the method has good operational tolerance and process robustness, which is beneficial to process window control and optimization in actual production. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a process flow diagram of the in-situ crystallization-passivation integrated preparation method of perovskite thin film in this invention; Figure 2 This is a schematic diagram of the perovskite solar cell structure in Example 1; Figure 3 This is a comparison chart of steady-state fluorescence spectroscopy (PL) tests for Example 1 and Comparative Example 1.

[0025] In the figure: 1. ITO conductive glass, 2. Magnetron sputtered nickel oxide layer, 3. Self-assembled monolayer, 4. Perovskite-passivation monolayer, 5. C60 electron transport layer, 6. BCP hole blocking layer, 7. Ag electrode. Detailed Implementation

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this description, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Firstly, such as Figure 1 As shown, this invention provides an integrated in-situ crystallization-passivation preparation method for perovskite thin films, specifically including the following steps: Step S1: Prepare perovskite precursor solution; Step S2: Coat the perovskite precursor solution onto the substrate to form a wet film; Step S3: Within 5 seconds after the wet film coating is completed, the wet film obtained in step S2 is purged with a nitrogen knife to obtain a perovskite intermediate film. Step S4: Coat a passivation layer solution onto the perovskite intermediate film obtained in step S3 to obtain a stacked film; Step S5: Perform a thermal annealing treatment on the laminated film obtained in step S4. During this annealing process, the perovskite intermediate film completes its final crystallization, and at the same time, passivating agent molecules penetrate into the perovskite intermediate film to achieve passivation.

[0030] In step S2, the coating method is spin coating, blade coating, or slot coating. In this step, the substrate can be glass or PET film containing ITO (indium tin oxide glass), FTO (fluorine-doped tin oxide glass), or other composite conductive film layers.

[0031] In step S3, the purging temperature of the nitrogen knife is 40–70°C, the gas flow rate is 10–40 L / min, and the purging time is 10–20 seconds.

[0032] In step S4, the coating method is slot coating or inkjet printing.

[0033] In step S4, the passivation layer solution includes a passivating agent and a solvent. The passivating agent is selected from at least one of Lewis bases, Lewis acids, and organic ammonium salts. The solvent is a solvent that does not dissolve the perovskite intermediate film. The Lewis base is selected from at least one of ammonium thiocyanate, urea iodide, TPPO, and PMMA. The organic ammonium salt is selected from at least one of phenylethyl ammonium iodide, ethylenediamine dihydroiodide, m-fluorophenylethylamine iodide, and butyl ammonium iodide. The solvent is at least one of isopropanol and ethanol.

[0034] In step S5, the process of one-time hot annealing is as follows: the annealing temperature is 80-150℃ and the annealing time is 10-30 minutes.

[0035] Secondly, the present invention provides a method for preparing a perovskite solar cell, specifically comprising the following steps: Step a: Clean the conductive substrate; Step b: Prepare the hole transport layer; Step c: Prepare a self-assembled monolayer; Step d: Prepare a perovskite-passivation layer monolithic layer; Step e: Prepare the electron transport layer; Step f: Prepare the electrode layer; In step d, the perovskite-passivation layer is prepared using the above-described method.

[0036] By performing P1 laser scribing on the conductive substrate before step a, performing P2 laser scribing on the battery between steps e and f, and performing P3 laser scribing on the battery after step f, a multi-cell series device can be fabricated.

[0037] In step b, the hole transport layer is prepared using methods such as PVD, spin coating, blade coating, and slot coating. In step c, the self-assembled monolayer is prepared by inkjet printing, blade coating, or slot coating. In step e, the electron transport layer is prepared by methods such as spin coating, blade coating, slot coating, and vapor deposition; In step f, the electrode layer is prepared using methods such as PVD, RPD, and vapor deposition.

[0038] Thirdly, the present invention also provides a perovskite solar cell, which is prepared by the above-described preparation method.

[0039] Example 1 like Figure 2 As shown, the perovskite solar cell in this embodiment has the following structure from bottom to top: ITO conductive glass 1, magnetron sputtered nickel oxide layer 2, self-assembled monolayer 3, perovskite-passivation integrated layer 4, C60 electron transport layer 5, BCP hole blocking layer 6, and Ag electrode 7.

[0040] The fabrication method of the perovskite solar cell in this embodiment specifically includes the following steps: (1) Preparation of P1 scribing: ITO conductive glass 1 is scribed with P1 scribing power of 6w and the total width of P1 scribing is 0.04mm; (2) Clean the ITO conductive glass 1 sequentially with detergent, deionized water (2 times), alcohol (2 times), and isopropanol for 20 minutes each. After ultrasonic cleaning, place the conductive glass in a 70℃ oven to dry, and then clean it with an ultraviolet ozone cleaner for 15~30 minutes before use. (3) Preparation of the nickel oxide layer 2 by magnetron sputtering: The cleaned ITO conductive glass 1 is placed in the magnetron sputtering cavity, and the vacuum is evacuated until the base pressure reaches 5×10⁻⁶. -4 Pa; Subsequently, at a sputtering power of 500 W and an argon flow rate of 50 sccm, NiOx target material was used for sputtering deposition for 10 minutes to form a uniform thin film with a thickness of about 50 nm on ITO conductive glass 1. This thin film is the magnetron sputtered nickel oxide layer 2. (4) Preparation of self-assembled monolayer 3: Weigh 0.5 mg of MeO-2PACz sample, add 1 mL of ethanol to dissolve and stir. After dissolution, use slit coating method with a coating speed of 50 mm / s, a liquid supply rate of 240 μL / s, and a coating gap of 90 μm to coat. After coating, place the substrate on the annealing table and anneal at 100℃ for 10 min to obtain self-assembled monolayer 3. (5) Preparation of the perovskite-passivation integral layer 4, including: (51) Prepare Cs solution with a stoichiometric concentration of 1.1 mol / L 0.1 The FA0.9PbI3 perovskite precursor solution was prepared by mixing N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 (v / v), with an additional 75 μL of methanol added. The precursor solution was stirred on a stirring table for 6 hours, and then filtered using a polytetrafluoroethylene (PTFE) filter with a pore size of 0.22 μm for later use. (52) A perovskite precursor solution was coated onto the self-assembled monolayer 3 to form a wet film; the coating process parameters were: coating speed 50 mm / s, gap 100 μm; (53) After the coating is completed, the above wet film is dried by nitrogen knife. The nitrogen knife purging temperature is 50°C, the air flow rate is 10L / min, and the purging time is 10 seconds to obtain an intermediate film with a wet surface but which has lost its fluidity. (54) After purging, use an inkjet printer to accurately print an isopropanol solution with a concentration of 0.5 mg / mL m-F-PEAI (m-fluorophenylethylamine iodide) on the above intermediate film; (55) After inkjet printing is completed, the resulting wet film is immediately placed on a heating table and annealed at 100 °C for 30 minutes to finally form a perovskite-passivation integrated functional layer 4. (6) Preparation of C60 electron transport layer 5: C60 was deposited by thermal evaporation at a rate of 0.2 Å / s and a thickness of 25 nm. (7) Preparation of BCP transport layer 6: BCP was deposited by thermal evaporation at a rate of 0.2 Å / s and a thickness of 6 nm. (8) Preparation of P2 scribing: Laser scribing is performed on the sample after step (6) above. The scribing power is 4.5w and the total width of P2 scribing is 0.03mm. (9) Preparation of Ag electrode 7: Ag was deposited by thermal evaporation at a rate of 0.45 Å / s and a thickness of 90–120 nm. (10) Preparation of P3 scribing: Laser scribing is performed on the sample after step (9) above. The scribing power is 5w and the total width of P3 scribing is 0.03mm.

[0041] Example 2 The difference from Example 1 is that in step (51), the perovskite precursor solution is composed of Cs. 0.05 FA 0.9 MA 0.05 PbI3.

[0042] Example 3 The difference from Example 1 is that in step (54), the passivating agent material is EDAI2 (ethylenediamine dihydroiodide).

[0043] Example 4 The difference from Example 1 is that in step (53), the nitrogen knife purging temperature is 60°C, the airflow speed is 10L / min, and the purging time is 10 seconds.

[0044] Example 5 The difference from Example 1 is that in step (53), the nitrogen knife purging temperature is 50°C, the airflow speed is 10L / min, and the purging time is 15 seconds.

[0045] Example 6 The difference from Example 1 is that in step (53), the nitrogen knife purging temperature is 50°C, the airflow speed is 20L / min, and the purging time is 10 seconds.

[0046] Comparative Example 1 The difference from Example 1 is that step (5) involves the preparation of the perovskite-passivation integral layer 4.

[0047] The preparation method of the perovskite-passivation integrated layer 4 in this comparative example is as follows: Prepare a Cs solution with a stoichiometric concentration of 1.1 mol / L. 0.1 A FA0.9PbI3 perovskite precursor solution was prepared using a mixture of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 (v / v), with an additional 75 μL of methanol added. The precursor solution was stirred on a stirring table for 6 hours, then filtered through a 0.22 μm pore size polytetrafluoroethylene (PTFE) filter. The blade coating parameters were as follows: coating speed 50 mm / s, gap 100 μm. Immediately after blade coating, the resulting wet film was subjected to vacuum flash evaporation for 7 seconds, followed by annealing at 100°C for 30 minutes to form the perovskite functional layer. Then, an isopropanol solution with a concentration of 0.5 mg / mL mF-PEAI was precisely printed onto the perovskite film using an inkjet printer. Immediately after inkjet printing, the resulting wet film was placed on a heating table and annealed at 100°C for 10 minutes to finally form the passivation layer.

[0048] Comparative Example 2 The difference from Example 1 is that in step (53), the nitrogen knife purging temperature is 80°C, the airflow speed is 10L / min, and the purging time is 10 seconds.

[0049] Comparative Example 3 The difference from Example 1 is that in step (53), the nitrogen knife purging temperature is 50°C, the airflow speed is 10L / min, and the purging time is 30 seconds.

[0050] Performance Characterization The battery performance of Examples 1 to 6 and Comparative Examples 1 to 3 was tested under AM 1.5G standard illumination, and the test results are shown in Table 1.

[0051] Table 1. Battery test results of Examples 1 to 6 and Comparative Examples 1 to 3.

[0052] As shown in Table 1, under standard illumination conditions of AM 1.5G and 100 mW / cm², the sample prepared using the in-situ crystallization-passivation integrated method and undergoing integrated synergistic annealing treatment exhibited significantly better performance parameters than Comparative Example 1 (two-step annealing method). Specifically, the optimal example (Example 1) achieved an open-circuit voltage (Voc) of 10.08 V, a fill factor (FF) of 78.65%, and a power conversion efficiency (PCE) of 20.63%, with a short-circuit current density (Jsc) reaching 23.42 mA / cm². In contrast, the Voc, FF, and Jsc in Comparative Example 1 were only 9.75 V, 72.14%, and 22.89 mA / cm², respectively, with the PCE ultimately decreasing to 17.89%, indicating that the untreated sample had significant deficiencies in carrier generation, transport, and collection.

[0053] This performance improvement is primarily attributed to the "passivation-first" preparation strategy. This strategy introduces a passivation layer before the final crystallization of the perovskite, allowing passivating agent molecules to penetrate to the grain growth front during heat treatment. This not only effectively modifies surface defects but also suppresses the formation of intrinsic iodine and lead vacancies during crystal growth, thereby significantly reducing the bulk defect density. Figure 3 As shown, PL spectral characterization of Example 1 and Comparative Example 1 revealed a significant enhancement in the PL peak intensity of Example 1, indicating that the "passivation-first" strategy effectively reduced defects on the perovskite surface and at grain boundaries—defects typically trap photogenerated carriers in the form of uncoordinated ions, inducing nonradiative recombination. Furthermore, this method helps to modulate the surface energy of crystal planes, promoting longitudinal growth of perovskite grains, increasing grain size, and reducing the number of grain boundaries, thereby further reducing the carrier recombination probability.

[0054] As can be seen from the data in Examples 2 to 6, adjusting the nitrogen purging parameters within a reasonable range can still maintain high device performance (PCE is above 20%), and the fluctuations in Jsc, Voc and FF are small. This indicates that the integrated crystallization-passivation process has good operational tolerance and process robustness, providing flexible space for parameter optimization in practical applications.

[0055] In summary, the perovskite-passivation integrated layer 4 of this invention involves a pre-processing passivation step, achieving synergistic crystallization and passivation through a single-step annealing process. This method not only simplifies the process and reduces energy consumption, but more importantly, it enables the passivating agent to actively suppress the formation of intrinsic defects during crystal growth, achieving "source passivation" and significantly reducing the bulk and interface defect density of the perovskite film. Perovskite solar cells prepared using this method exhibit higher photoelectric conversion efficiency and excellent stability, making them suitable for large-area industrial production.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for in-situ crystallization-passivation integrated preparation of perovskite thin films, characterized in that: Specifically, the steps include the following: Step S1: Prepare perovskite precursor solution; Step S2: Coat the perovskite precursor solution onto the substrate to form a wet film; Step S3: Within 5 seconds after the wet film coating is completed, the wet film obtained in step S2 is immediately purged with a nitrogen knife to obtain a perovskite intermediate film. Step S4: Coat a passivation layer solution onto the perovskite intermediate film obtained in step S3 to obtain a stacked film; Step S5: Perform a thermal annealing treatment on the laminated film obtained in step S4. During this annealing process, the perovskite intermediate film completes its final crystallization, and at the same time, passivating agent molecules penetrate into the perovskite intermediate film to achieve passivation.

2. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 1, characterized in that: In step S2, the coating method is spin coating, scraping coating, or slot coating.

3. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 1, characterized in that: In step S3, the purging temperature of the nitrogen knife is 40–70°C, the gas flow rate is 10–40 L / min, and the purging time is 10–20 seconds.

4. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 1, characterized in that: In step S4, the coating method is slot coating or inkjet printing.

5. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 1, characterized in that: In step S4, the passivation layer solution includes a passivating agent and a solvent. The passivating agent is selected from at least one of Lewis bases, Lewis acids, and organic ammonium salts. The solvent is a solvent that does not dissolve the perovskite intermediate film.

6. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 5, characterized in that: The Lewis base is selected from at least one of ammonium thiocyanate, urea iodide, TPPO, and PMMA; the organic ammonium salt is selected from at least one of phenylethyl ammonium iodide, ethylenediamine dihydroiodide, m-fluorophenylethylamine iodide, and butyl ammonium iodide; and the solvent is at least one of isopropanol and ethanol.

7. The in-situ crystallization-passivation integrated preparation method of perovskite thin films according to claim 1, characterized in that: In step S5, the process of one-time hot annealing is as follows: the annealing temperature is 80-150℃ and the annealing time is 10-30 minutes.

8. A method for preparing a perovskite solar cell, characterized in that: Specifically, the steps include the following: Step a: Clean the conductive substrate; Step b: Prepare the hole transport layer; Step c: Prepare a self-assembled monolayer; Step d: Prepare a perovskite-passivation layer monolithic layer; Step e: Prepare the electron transport layer; Step f: Prepare the electrode layer; In step d, the perovskite-passivation layer is prepared by the preparation method described in any one of claims 1 to 7.

9. The method for preparing a perovskite solar cell according to claim 8, characterized in that: By performing P1 laser scribing on the conductive substrate before step a, performing P2 laser scribing on the battery between steps e and f, and performing P3 laser scribing on the battery after step f, a multi-cell series device can be fabricated.

10. A perovskite solar cell, characterized in that: The perovskite solar cell is prepared using the method described in claim 8 or 9.

Images