Preparation methods of perovskite precursor solution, perovskite light absorption layer and perovskite solar cell based on non-halogen lead source

Abstract

The invention belongs to the technical field of perovskite solar cell preparation, and discloses a preparation method of a perovskite precursor solution, a perovskite light absorption layer and a perovskite solar cell based on a non-halogen lead source. A preparation method of a perovskite precursor solution based on a non-halogen lead source comprises the following steps: dissolving the non-halogen lead source, an organic halide AX and an organic acid in a mixed solvent, and continuously stirring at 50-70 DEG C until a solid is completely dissolved to obtain the perovskite precursor solution. According to the invention, organic acid is introduced as an additive to regulate and control crystal growth kinetics, so that the thin film can form a compact and continuous film layer more easily, and the problems of insufficient coverage rate, increased holes and the like are greatly improved; according to the method, the high-quality thin film can be stably prepared under the high-humidity air condition, dependence on the inert atmosphere is not needed, the process complexity and the production cost are greatly reduced, meanwhile, the photoelectric conversion efficiency of a device is improved, the environmental tolerance of the device is enhanced, and the good long-term stability of the device is still kept under the action of air humidity.

Description

Technical Field

[0001] This invention belongs to the field of perovskite thin film preparation technology, specifically relating to a method for preparing a perovskite precursor solution, a perovskite light-absorbing layer, and a perovskite solar cell based on a non-lead halide source. Background Technology

[0002] Organic-inorganic lead halide perovskite materials are considered a class of optoelectronic semiconductor materials with great development potential due to their advantages such as tunable bandgap, high carrier mobility, long carrier diffusion length, and low exciton binding energy. Since the efficiency of early perovskite solar cells was first reported, their energy conversion efficiency has been significantly improved in a short period of time, and the efficiency of the cells has approached that of crystalline silicon solar cells, making them a potential alternative to silicon-based technologies for the next generation.

[0003] Despite significant breakthroughs in efficiency for perovskite solar cells, the intrinsic instability of perovskite materials to ambient humidity remains a major factor hindering their commercialization. In existing technologies, high-quality perovskite films typically require fabrication in an inert atmosphere glove box, which significantly increases equipment costs and process complexity, hindering large-scale manufacturing. The continuity, density, grain size, and defect density of perovskite films have a decisive impact on device efficiency and stability; therefore, how to fabricate high-quality perovskite films in air has become an important research direction in this field. To achieve stable film formation in air, some studies have attempted to improve film morphology and moisture resistance by optimizing precursor formulations, adjusting process conditions, or introducing additives. Among these, thiocyanate ions (SCN) are particularly important. - As a pseudohalogen ion, Pb(SCN)₂ has a strong binding affinity to lead ions. Using Pb(SCN)₂ as a lead source can improve the moisture resistance of the film and has been proven to effectively delay the degradation of perovskite films in high humidity environments. Furthermore, perovskite films and corresponding photovoltaic devices obtained through one-step or two-step processes exhibit high humidity tolerance and long-term stability.

[0004] However, existing air-based Pb(SCN)₂ preparation methods still have significant shortcomings in terms of film quality. Due to the strong coordination between thiocyanate ions and lead ions, the nucleation and crystallization kinetics of the precursor solution are significantly affected, making it more prone to non-uniform nucleation and slow crystallization during film formation. This results in insufficient film surface coverage, uneven grain size, numerous pores, and high roughness. These defects not only increase carrier recombination and reduce the photoelectric conversion efficiency of the device, but also lead to poor contact between the hole transport layer and the perovskite light-absorbing layer, further exacerbating energy loss and stability degradation. Furthermore, water molecules, which are ubiquitous in the air, compete for coordination with SCN⁻-containing precursors or promote non-uniform transformation of the intermediate phase, making the crystallization process of the Pb(SCN)₂ system more complex and uncontrollable, increasing the probability of film defect formation. Therefore, although Pb(SCN)₂ has excellent moisture resistance potential, its film formation process under air conditions still lacks effective control methods, making it difficult to directly obtain continuous, dense, and high-crystallinity perovskite films. Summary of the Invention

[0005] To address the shortcomings of existing technologies, such as the requirement that "high-quality perovskite thin films typically need to be prepared in an inert atmosphere glove box and cannot be prepared in air," one objective of this invention is to provide a method for preparing a perovskite precursor solution based on a non-lead halide source; another objective is to provide a method for preparing a perovskite light-absorbing layer based on a non-lead halide source; and a third objective is to provide a method for preparing a perovskite solar cell based on a non-lead halide source.

[0006] To achieve one of the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing a perovskite precursor solution based on a non-halogenated lead source involves dissolving a non-halogenated lead source, an organic halide AX, and an organic acid in a mixed solvent, and continuously stirring at 50-70°C until the solid is completely dissolved to obtain a perovskite precursor solution. Wherein, A in AX represents an organic cation and X represents a halide anion; the raw material ratio is non-halogen lead source: AX: organic acid: mixed solvent = 1 mmol: (3~3.5) mmol: (0.2~3) mmol: (0.7~1) mL; by volume ratio, the mixed solvent is composed of DMF and DMSO in the ratio of DMF: DMSO = (4~9): 1.

[0007] Preferably, the non-halogen lead source is Pb(SCN)2.

[0008] Preferably, the AX is CH3NH3I or CH(NH2)2I.

[0009] Preferably, the organic acid is formic acid, acetic acid, or oxalic acid.

[0010] To achieve the second objective mentioned above, the technical solution adopted by the present invention is as follows: The method for preparing a perovskite light-absorbing layer using the perovskite precursor solution based on a non-halogen lead source is as follows: Under an air environment of 10~90%RH (relative humidity), the perovskite precursor solution is dropped onto the substrate surface, spin-coated to form a film, and about 5~10s before the end of the spin-coating process, an anti-solvent is dropped to form an intermediate phase film; the intermediate phase film is annealed to obtain the perovskite light-absorbing layer.

[0011] Preferably, the antisolvent is ethyl acetate, methyl butyrate, or methyl formate.

[0012] Preferably, the spin coating speed is 4000~5000 rpm and the time is 20~30s; the annealing adopts a two-step annealing method: first pre-annealing at 60~80℃ for 1~5min, and then further annealing at 90~120℃ for 10~15min; the perovskite precursor solution : antisolvent = 1 : (8~10) by volume.

[0013] To achieve the third objective mentioned above, the technical solution adopted by the present invention is as follows: A method for fabricating perovskite solar cells using the aforementioned perovskite precursor solution based on a non-lead halide source: From bottom to top, the perovskite solar cell sequentially comprises a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode; the fabrication steps of the perovskite solar cell are as follows: S1. Clean and pre-treat the transparent conductive substrate; S2. Spin-coat the electron transport layer precursor solution onto the transparent conductive substrate obtained in step S1, and anneal to obtain the electron transport layer. S3. In an air environment of 10%~90%RH (relative humidity), the perovskite precursor solution is dropped onto the surface of the electron transport layer obtained in step S2, and a film is formed by spin coating. About 5~10 seconds before the end of the spin coating process, an anti-solvent is dropped to form an intermediate phase film. The intermediate phase film is annealed to obtain a perovskite light-absorbing layer. S4. Spin-coat the hole transport layer precursor solution onto the perovskite light-absorbing layer obtained in step S3 to obtain the hole transport layer. S5. Deposit a metal electrode onto the hole transport layer obtained in step S4 to obtain a perovskite solar cell.

[0014] Preferably, the antisolvent is ethyl acetate, methyl butyrate, or methyl formate.

[0015] Preferably, the spin coating speed is 4000~5000 rpm and the time is 20~30s; the annealing adopts a two-step annealing method: first pre-annealing at 60~80℃ for 1~5min, and then further annealing at 90~120℃ for 10~15min; the perovskite precursor solution : antisolvent = 1 : (8~10) by volume.

[0016] In this invention, those skilled in the art can select the transparent conductive glass, electron transport layer, hole transport layer, and metal electrode within the conventional range and prepare or pre-treat them according to existing technologies; however, this invention proposes that the transparent conductive substrate is preferably FTO conductive glass or ITO conductive glass, the electron transport layer is SnO2 or TiO2, the hole transport layer is Spiro-OMeTAD, and the metal electrode is Au or Ag.

[0017] Further, the preferred step S1 is as follows: the transparent conductive substrate is ultrasonically cleaned sequentially with deionized water, isopropanol, acetone and anhydrous ethanol; after cleaning, the substrate is dried with high-purity nitrogen and treated with ultraviolet ozone before use.

[0018] Further, step S2 is preferably as follows: spin-coating a SnO2 precursor dispersion onto the transparent conductive substrate obtained in step S1, followed by annealing to obtain a SnO2 electron transport layer; wherein, the concentration of the SnO2 precursor dispersion is controlled at 2~10wt%, the spin-coating conditions are low speed 500~1000rpm spin-coating for 3~10s, followed by high speed 2500~4000rpm spin-coating for 20~30s, and the annealing conditions are annealing at 60~200℃ for 30~60min.

[0019] Further, step S4 is preferably as follows: Spiro-OMeTAD solution is spin-coated onto the perovskite light-absorbing layer obtained in step S3 to obtain a hole transport layer; wherein, the Spiro-OMeTAD solution is spin-coated onto the surface of the perovskite light-absorbing layer at a concentration of 50~100mg / mL, the spin-coating speed is 1000~4000rpm, the spin-coating time is 20~60s, and then left to stand in room temperature air for 6~24h to allow it to spontaneously oxidize and form a hole transport layer with a thickness of about 100~200nm.

[0020] Further, step S5 is preferably: a metal electrode is prepared on the hole transport layer obtained in step S4 by vacuum evaporation, wherein the thickness of the metal electrode is preferably 50~120nm.

[0021] Compared with existing preparation processes, the present invention has the following advantages and beneficial effects: By introducing organic acids as additives to regulate crystal growth kinetics, perovskite films are more likely to form dense and continuous layers, significantly improving problems such as insufficient coverage and increased porosity. The participation of organic acids promotes uniform nucleation and stable growth of grains, reduces grain boundary defects, and thus yields perovskite films with high crystallinity, large grains, and low defect density, which is beneficial for efficient carrier transport. Thanks to SCN... - Thanks to the inherent moisture resistance of the perovskite film and the film-forming control strategy provided by this invention, the method of this invention can stably prepare high-quality films under high humidity air conditions without relying on an inert atmosphere, significantly reducing process complexity and production costs. The improved perovskite film is uniform, dense, and has few defects, which significantly reduces interfacial recombination loss and thus improves the photoelectric conversion efficiency of the device. At the same time, the dense perovskite film structure enhances the environmental tolerance of the device, enabling it to maintain good long-term stability under the influence of air humidity. The additive strategy of this invention has low equipment requirements, a stable precursor system, strong controllability of the film-forming process, and uses environmentally friendly raw materials, making it suitable for low-cost, large-area industrial production scenarios. Attached Figure Description

[0022] Figure 1 Schematic diagram of a perovskite solar cell; Figure 2 SEM planar image of the perovskite solar cell prepared in Example 2; Figure 3 SEM planar images of the perovskite solar cells prepared in the comparative example; Figure 4 XRD spectra of the perovskite films prepared in Example 2 and the comparative example; Figure 5 Absorption spectra of the perovskite thin films prepared in Example 2 and the comparative example; Figure 6 PL spectra of the perovskite thin films prepared in Example 2 and the comparative example; Figure 7 : Current density-voltage curve of the perovskite solar cell prepared in Example 1; Figure 8 : Current density-voltage curve of the perovskite solar cell prepared in Example 2; Figure 9 : Current density-voltage curve of the perovskite solar cell prepared in Example 3; Figure 10 : Current density-voltage curve of the perovskite solar cell prepared in Example 4; Figure 11 : Current density-voltage curves of perovskite solar cells prepared in comparison; Figure 12Efficiency degradation graphs of perovskite solar cells prepared in Example 2 and the comparative example when exposed to air (25°C, ~30%RH) without any encapsulation. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the described embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0024] Example 1 A perovskite solar cell based on a non-halogen lead source, such as Figure 1 As shown, from bottom to top, the perovskite solar cell sequentially comprises a transparent conductive substrate 1, an electron transport layer 2, a perovskite light-absorbing layer 3, a hole transport layer 4, and a metal electrode 5; the fabrication steps of the perovskite solar cell are as follows: S1. Substrate cleaning and pretreatment: The FTO conductive glass is ultrasonically cleaned by sequentially immersing it in deionized water, isopropanol, acetone and anhydrous ethanol; after cleaning, the FTO conductive glass is dried with high-purity nitrogen and then subjected to ultraviolet ozone treatment before use. S2. Preparation of electron transport layer: A 15% (w / w) commercial SnO2 colloidal solution was mixed with deionized water at a mass ratio of 1:5 to obtain a 2.5% (w / w) SnO2 colloidal dilution. The solution was then treated under stirring for 1 hour to obtain a SnO2 precursor dispersion for later use. 90 μL of the SnO2 precursor dispersion was dropped onto the FTO conductive glass surface treated in step S1. The spin-coating conditions were: first spin-coating at 500 rpm for 3 seconds, then spin-coating at 3000 rpm for 30 seconds. After annealing on a hot plate at 150°C for 30 minutes, a SnO2 electron transport layer was formed. S3. Preparation of the perovskite light-absorbing layer: 1 mmol Pb(SCN)2, 3 mmol CH3NH3I and 0.5 mmol HAc were added to 1 mL of a mixed solvent (composed of DMF and DMSO in a volume ratio of 4:1). The mixture was stirred continuously at 60 °C for 12 h to completely dissolve the solids and form a homogeneous perovskite precursor solution. Subsequently, under 60% RH air, 50 μL of the perovskite precursor solution was dropped onto the surface of the SnO2 electron transport layer obtained in step S2 and spin-coated to form a film. The spin-coating conditions were 5000 rpm for 30 s. In a one-step process, about 5 s before the end of the spin-coating process, 400 μL of the green anti-solvent ethyl acetate was dropped to form an intermediate phase film. The obtained intermediate phase film was pre-annealed at 60 °C for 1 min and then further annealed at 100 °C for 10 min to obtain the perovskite light-absorbing layer. S4. Hole transport layer preparation: 72.3 mg of Spiro-OMeTAD was added to 1 mL of chlorobenzene and stirred to form a homogeneous solution; 28 μL of TBP and 18 μL of Li-TFSI dopant were added to the solution in sequence, wherein the Li-TFSI dopant was prepared by dissolving 520 mg of Li-TFSI in 1 mL of acetonitrile; the mixture was stirred at room temperature for 12 h and then filtered to remove insoluble matter; subsequently, the filtered Spiro-OMeTAD solution was dropped onto the surface of the perovskite light-absorbing layer obtained in step S3 and spin-coated at 3000 rpm for 60 s, and then allowed to stand in room temperature air for 12 h to allow it to spontaneously oxidize and form a hole transport layer; S5. Electrode fabrication: Au electrodes are deposited on the surface of the hole transport layer obtained in step S4 in a vacuum environment by thermal evaporation. The thickness of the Au electrodes is controlled at 60~80nm by film thickness monitoring. Thus, a perovskite solar cell is obtained.

[0025] Example 2 The difference from Example 1 is that in step S3, the HAc additive is added at a molar ratio of HAc:Pb(SCN)2 = 1:1; all other aspects are the same as in Example 1.

[0026] Example 3 The difference from Example 1 is that in step S3, the HAc additive is added at a molar ratio of HAc:Pb(SCN)2 = 2:1; all other aspects are the same as in Example 1.

[0027] Example 4 The difference from Example 1 is that in step S3, “CH(NH2)2I” is used instead of “CH3NH3I”; everything else is the same as in Example 1.

[0028] Comparative Example The difference from Example 1 is that in step S3, HAc was not added; that is, Pb(SCN)2 and CH3NH3I were directly added to a mixed solvent composed of DMF and DMSO in a volume ratio of 4:1 at a molar ratio of 1:3. The mixed solution was stirred continuously at 60°C for 12 hours to completely dissolve the solid and form a homogeneous perovskite precursor solution. All other aspects are the same as in Example 1.

[0029] Product characterization Figure 2 This is a SEM planar image of the perovskite light-absorbing layer prepared in Example 2. Figure 3The image shows a SEM planar view of the perovskite light-absorbing layer prepared in comparison. It can be seen that, compared to the non-additive perovskite film, the perovskite film containing HAc additives has a dense, pore-free surface, exhibiting ultra-large grains of 2–3 μm. High-quality perovskite films help reduce the defect state density within the film and decrease the erosion of the film by external environmental factors (such as moisture and oxygen), thereby significantly improving the long-term stability of the perovskite film and the devices fabricated based on it.

[0030] Figure 4 The images show the XRD patterns of the perovskite light-absorbing layers prepared in Example 2 and the comparative example. Figure 4 It can be seen that the perovskite films all showed strong diffraction peaks in the (110) and (220) crystal orientations at 14.05° and 28.38°, indicating that they have strong single orientation. The crystallinity of the perovskite films containing additives is relatively enhanced, indicating that the additives do improve the crystallinity of the films.

[0031] Figure 5 The images show the absorption spectra of the perovskite light-absorbing layers prepared in Example 2 and the comparative example. From... Figure 5 It can be seen that the absorption edges are all located at 780 nm, indicating that the additives did not change the chemical composition or band structure (band gap) of the perovskite. Furthermore, the light absorption intensity of the film after adding the additives showed a certain degree of improvement, meaning that the film can capture more solar energy, creating favorable conditions for obtaining higher photocurrent output.

[0032] Figure 6 The PL spectra of the perovskite absorbing layers prepared in Example 2 and the comparative example are shown. Figure 6 It can be seen that both films exhibit luminescence characteristics at around 772 nm, and the PL emission peak of the film containing additives is relatively high, indicating that the radiative recombination inside the corresponding film is enhanced, and correspondingly, the non-radiative recombination is reduced, that is, the defect state density decreases sequentially.

[0033] Performance testing Under AM1.5 standard illumination conditions, with an effective area of ​​0.09 cm² 2 Under the conditions, JV tests were carried out on the perovskite solar cells obtained in Examples 1-4 and Comparative Example 1.

[0034] Figure 7 The current density-voltage (JV) characteristic curves of the perovskite solar cell prepared in Example 1 are shown. Figure 7 It can be seen that the device exhibits an open-circuit voltage (Voc) of approximately 1.05V and an open-circuit voltage (A / cm). 2 With a short-circuit current density (Jsc) and a fill factor of approximately 0.75, the corresponding photoelectric conversion efficiency is approximately 17.25%.

[0035] Figure 8 The current density-voltage (JV) characteristic curves of the perovskite solar cell prepared in Example 2 are shown. Figure 8 It can be seen that the device exhibits an open-circuit voltage (Voc) of approximately 1.06V and an open-circuit voltage (A / cm). 2 With a short-circuit current density (Jsc) and a fill factor of approximately 0.77, the corresponding photoelectric conversion efficiency is approximately 18.63%.

[0036] Figure 9 The current density-voltage (JV) characteristic curves of the perovskite solar cell prepared in Example 3 are shown. Figure 9 It can be seen that the device exhibits an open-circuit voltage (Voc) of approximately 1.04V and an open-circuit voltage (A / cm). 2 With a short-circuit current density (Jsc) and a fill factor of approximately 0.75, the corresponding photoelectric conversion efficiency is approximately 17.84%.

[0037] Figure 10 The current density-voltage (JV) characteristic curves of the perovskite solar cell prepared in Example 4 are shown. Figure 10 It can be seen that the device exhibits an open-circuit voltage (Voc) of approximately 1.02V and an open-circuit voltage (A / cm). 2 With a short-circuit current density (Jsc) and a fill factor of approximately 0.61, the corresponding photoelectric conversion efficiency is approximately 13.92%.

[0038] Figure 11 The current density-voltage (JV) characteristic curves of the perovskite solar cell prepared for comparison are shown. Figure 11 It can be seen that the device exhibits an open-circuit voltage (Voc) of approximately 1.02V and an open-circuit voltage (A / cm). 2 With a short-circuit current density (Jsc) and a fill factor of approximately 0.74, the corresponding photoelectric conversion efficiency is approximately 16.68%.

[0039] Based on the JV test results above, it can be seen that the perovskite solar cell prepared in Example 2 has the best performance.

[0040] Figure 12 The efficiency degradation graphs for the perovskite solar cells prepared in Example 2 and the comparative example are shown when exposed to air (25°C, ~30%RH) without any encapsulation. Figure 12 As can be seen, the perovskite solar cells prepared with the additive-containing perovskite thin film can still maintain 85% of the original efficiency after 4500 hours, demonstrating excellent air stability.

Claims

1. A method for preparing a perovskite precursor solution based on a non-halogenated lead source, characterized in that: A non-halogenated lead source, an organic halide AX, and an organic acid are dissolved in a mixed solvent and stirred continuously at 50-70°C until the solid is completely dissolved to obtain a perovskite precursor solution. Wherein, A in AX represents an organic cation and X represents a halide anion; the raw material ratio is non-halogen lead source: AX: organic acid: mixed solvent = 1 mmol: (3~3.5) mmol: (0.2~3) mmol: (0.7~1) mL; by volume ratio, the mixed solvent is composed of DMF and DMSO in the ratio of DMF: DMSO = (4~9):

1.

2. The method for preparing a perovskite precursor solution based on a non-halogenated lead source as described in claim 1, characterized in that: The non-halogenated lead source is Pb(SCN)2.

3. The method for preparing a perovskite precursor solution based on a non-halogenated lead source as described in claim 1, characterized in that: The AX is CH3NH3I or CH(NH2)2I.

4. The method for preparing a perovskite precursor solution based on a non-halogenated lead source as described in claim 1, characterized in that: The organic acid is formic acid, acetic acid, or oxalic acid.

5. A method for preparing a perovskite light-absorbing layer using a perovskite precursor solution based on a non-lead halide source as described in any one of claims 1 to 4, characterized in that: In an air environment of 10~90%RH, the perovskite precursor solution is dropped onto the substrate surface, spin-coated to form a film, and about 5~10 seconds before the end of the spin-coating process, the anti-solvent is dropped to form an intermediate phase film. The mesophase film was annealed to obtain a perovskite light-absorbing layer.

6. The method for preparing a perovskite light-absorbing layer based on a non-lead halide source perovskite precursor solution as described in claim 5, characterized in that: The antisolvent is ethyl acetate, methyl butyrate, or methyl formate.

7. The method for preparing a perovskite light-absorbing layer based on a non-lead halide source perovskite precursor solution as described in claim 5, characterized in that: Spin coating speed is 4000~5000 rpm, time is 20~30s; annealing adopts two-step annealing method: first pre-annealing at 60~80℃ for 1~5min, and then further annealing at 90~120℃ for 10~15min; by volume ratio, perovskite precursor solution : antisolvent = 1 : (8~10).

8. A method for preparing perovskite solar cells using a perovskite precursor solution based on a non-halogenated lead source as described in any one of claims 1 to 4, characterized in that: From bottom to top, the perovskite solar cell sequentially comprises a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode; the fabrication steps of the perovskite solar cell are as follows: S1. Clean and pre-treat the transparent conductive substrate; S2. Spin-coat the electron transport layer precursor solution onto the transparent conductive substrate obtained in step S1, and anneal to obtain the electron transport layer. S3. Under an air environment of 10~90%RH, the perovskite precursor solution is dropped onto the surface of the electron transport layer obtained in step S2, and a film is formed by spin coating. About 5~10 seconds before the end of the spin coating process, an anti-solvent is dropped to form an intermediate phase film. The intermediate phase film is annealed to obtain a perovskite light-absorbing layer. S4. Spin-coat the hole transport layer precursor solution onto the perovskite light-absorbing layer obtained in step S3 to obtain the hole transport layer. S5. Deposit a metal electrode onto the hole transport layer obtained in step S4 to obtain a perovskite solar cell.

9. The method for preparing perovskite solar cells based on a non-halogenated lead source perovskite precursor solution as described in claim 8, characterized in that: The antisolvent is ethyl acetate, methyl butyrate, or methyl formate.

10. The method for preparing perovskite solar cells based on a non-halogenated lead source perovskite precursor solution as described in claim 8, characterized in that: The spin coating speed is 4000~5000 rpm and the time is 20~30s; the annealing adopts a two-step annealing method: first, pre-annealing at 60~80℃ for 1~5min, and then further annealing at 90~120℃ for 10~15min; the perovskite precursor solution : antisolvent = 1 : (8~10) by volume; the transparent conductive glass is FTO conductive glass or ITO conductive glass, the electron transport layer is SnO2 or TiO2, the hole transport layer is Spiro-OMeTAD, and the metal electrode is Au or Ag.

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