Method for enhancing stability of perovskite thin film
By using deuterated formamidine iodide to deposit perovskite films, the instability problem of perovskite materials was solved, the photoelectric conversion efficiency and stability of perovskite solar cells were improved, and long-term stable operation was achieved.
Patent Information
- Application Number
- CN202510580091.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-07
- Publication Date
- 2025-09-09
AI Technical Summary
The instability of perovskite materials causes the performance of perovskite solar cells to deteriorate under light and heating environments, affecting their practical applications.
Using deuterated formamidine iodide as raw material, perovskite films are deposited through specific spin coating and annealing steps to prepare stable perovskite solar cells, inhibiting the deprotonation process of formamidine ions and reducing the decomposition of perovskite.
It improves the photoelectric conversion efficiency of perovskite solar cells, ensures high efficiency under long-term illumination, prolongs the stability of perovskite solar cells, and reduces the decomposition of perovskite materials.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of inorganic chemistry, and in particular relates to a method for enhancing the stability of a perovskite film. Background Art
[0002] Unlike traditional, non-renewable fossil fuels, solar energy, as a renewable, clean energy source, is virtually inexhaustible. Therefore, solar energy has significant potential to improve the world's energy structure and alleviate energy pressures. Solar cells are devices that directly convert light energy into electrical energy through the photoelectric or photochemical effects. Currently, commercial solar cells primarily use crystalline silicon as the light-absorbing material.
[0003] Among emerging light-absorbing materials, perovskite materials offer advantages such as low cost, all-solution fabrication, and compatibility with flexible substrates. In the past few years, the certified power conversion efficiency of perovskite solar cells (PSCs) has reached 26.81%, a performance comparable to commercial silicon-based solar cells. However, the inherent instability of perovskite materials has hindered the practical application of PSCs. Environmental factors such as light and heat can degrade perovskite materials and lead to decreased cell performance. Therefore, there is an urgent need to develop methods to enhance the inherent stability of perovskite materials and improve the operational stability of perovskite solar cells. Summary of the Invention
[0004] The purpose of the present invention is to provide a method for enhancing the stability of perovskite thin films.
[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] The present invention provides a method for enhancing the stability of a perovskite film, comprising the following steps:
[0007] The first step is the preparation of the hole transport layer
[0008] Spin-coat a hole transport layer solution with a concentration of 0.1-1 mg / mL (preferably 0.3, 0.5 mg / mL) on the substrate and heat to obtain a hole transport layer;
[0009] Alternatively, nickel (II) acetate tetrahydrate and strontium chloride hexahydrate in a molar ratio of 1 to 50:1 (preferably 20:1) are dissolved in 2-methoxyethanol, stirred at 50 to 70°C (preferably 60°C) for 0.5 to 2 h (preferably 1 h), the solution is allowed to stand at room temperature for 1 to 24 h (preferably 24 h), spin-coated on a substrate, heated at 140 to 170°C (preferably 150°C) for 1 to 10 minutes (preferably 5 minutes), cooled to room temperature, and annealed at 450 to 600°C (preferably 500°C) for 0.5 to 2 h (preferably 1 h) to obtain a hole transport layer;
[0010] The substrate material is selected from an ITO substrate and a FTO conductive glass. The ITO substrate has a size of 1.3×1.5 cm. The FTO conductive glass has a length×width=1.5 cm×1.3 cm, a glass substrate thickness of 2 mm, and a conductive layer thickness of 500 nm.
[0011] The hole transport layer solution is prepared by dissolving the hole transport layer material in ethanol to obtain a hole transport layer solution with a concentration of 0.1 to 1 mg / mL (preferably 0.3 or 0.5 mg / mL).
[0012] The material of the hole transport layer is selected from [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid (MeO-2PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphoric acid (Me-4PACz), [2-(9H-carbazole-9-yl)ethyl]phosphonic acid (2-PACz), poly(3,4-ethylenedioxythiophene) (PEDOT:PSS), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)]amine (PTAA), poly-3-hexylthiophene (P3HT), nickel oxide (NiO x ), copper oxide (CuO x )wait.
[0013] The spin coating parameters in the first step were: 3000 rpm for 30 seconds.
[0014] The heating conditions in the first step are: heating at a temperature of 90-110° C. (preferably 100° C.) for 5-20 minutes (preferably 10 minutes).
[0015] The second step is the preparation of the perovskite light absorbing layer
[0016] PbI2, deuterated formamidine iodide, and methylamine hydrochloride (MACl) at a molar ratio of 1:1:0.05-0.5 (preferably 1:1:0.1) are dissolved in DMF and DMSO solvents, and spin-coated on the obtained hole transport layer. The layer is rinsed with an antisolvent before the spin coating is completed, and then placed in air after the spin coating is completed. The layer is annealed for the first time and then annealed for the second time to obtain a perovskite light-absorbing layer.
[0017] The volume ratio of DMF to DMSO is 4:1.
[0018] The spin coating parameters in the second step were: 6000 rpm for 30 s.
[0019] In the second step, the anti-solvent rinsing time before the end of spin coating is 10 s.
[0020] The anti-solvent is selected from chlorobenzene, toluene, ethyl acetate and the like.
[0021] In the second step, the first annealing is performed at a temperature of 140-160° C. (preferably 150° C.) for 5-20 minutes (preferably 10 minutes).
[0022] In the second step, the second annealing is performed at a temperature of 90-110° C. (preferably 100° C.) for 5-20 minutes (preferably 10 minutes).
[0023] The preparation method of the deuterated formamidine iodide:
[0024] Combine formamidine iodide and a deuterated reagent at a molar ratio of 1:1 to 60 (preferably 1:40), stir overnight, and lyophilize to obtain deuterated formamidine iodide. The initial deuteration ratio is approximately 90%, and this step can be repeated to increase the deuteration ratio.
[0025] The deuterated reagent is selected from heavy water, deuterated acetic acid, deuterated ethanol, deuterated formic acid, deuterated acetic acid, and deuterated ethylamine.
[0026] Step 3: Preparation of electron transport layer
[0027] The perovskite light-absorbing layer was cooled, and an electron transport layer material solution with a concentration of 5-15 mg / mL (preferably 10 mg / mL) was spin-coated (spin coating parameters were 2000 rpm, 45 s); followed by spin coating of a hole blocking layer solution with a concentration of 0.1-1 mg / mL (preferably 0.5 mg / mL) (spin coating parameters were 4000 rpm, 45 s); the perovskite solar cell was obtained by heating, cooling, and evaporating electrodes.
[0028] In the third step, the heating condition is: heating at a temperature of 60-80° C. (preferably 70° C.) for 5-20 minutes (preferably 15 minutes).
[0029] Preparation of the electron transport layer material solution: dissolving the electron transport layer material in chlorobenzene to obtain an electron transport layer material solution with a concentration of 5-15 mg / mL (preferably 10 mg / mL).
[0030] The material of the electron transport layer is selected from [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 BM), [6,6]-phenyl-C71-butyric acid methyl ester (PC 71 BM), fullerene C60, fullerene C70, indene-C60 bisadduct (ICBA), etc.
[0031] Preparation of the hole blocking layer solution: dissolving the hole blocking layer material in anhydrous ethanol to obtain a hole blocking layer material solution with a concentration of 0.1-1 mg / mL (preferably 0.5 mg / mL).
[0032] The hole blocking layer is made of a material selected from 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP).
[0033] The back electrode is selected from a gold electrode.
[0034] The structure of the perovskite solar cell is as follows from bottom to top: substrate layer, hole transport layer, perovskite light absorbing layer, electron transport layer, hole blocking layer, and back electrode.
[0035] The thickness of the glass substrate in the ITO substrate is 1 mm, and the thickness of the indium tin oxide conductive film is 500 nm.
[0036] The thickness of the hole transport layer is 50 nm.
[0037] The thickness of the perovskite light absorbing layer is 600 nm.
[0038] The thickness of the electron transport layer is 20 nm.
[0039] The thickness of the hole blocking layer is 5 nm.
[0040] The thickness of the back electrode is 100 nm.
[0041] Due to the adoption of the above technical solution, the present invention has the following advantages and beneficial effects:
[0042] The present invention provides a method for enhancing the stability of perovskite films. Deuterated formamidine iodide is used as a raw material to deposit perovskite films. The prepared perovskite solar cell has a photoelectric conversion efficiency of 25.08% (with an effective cell area of 0.0625 cm). 2), and perovskite solar cells can maintain 97% of their original efficiency after 1264 hours of illumination.
[0043] The present invention provides a method for enhancing the stability of perovskite films. Using deuterated formamidinium iodide as a raw material to deposit the perovskite film, the method effectively inhibits the deprotonation of formamidinium ions and reduces the decomposition of the formamidinium-based perovskite. Deuteration doubles the mass-to-charge ratio of the small number of protons dissociated from the perovskite film, inhibiting proton migration along the built-in electric field under the operating conditions of the perovskite solar cell, further reducing the decomposition of the formamidinium-based perovskite.
[0044] The present invention provides a method for enhancing the stability of perovskite films. Deuterated formamidine iodide is used as a raw material to deposit the perovskite film, suppressing the deprotonation reaction of the formamidine iodide, thereby preparing a formamidine-based perovskite solar cell with excellent stability. Deuterated formamidine iodide refers to a hydrogen atom directly attached to a nitrogen atom in formamidine iodide in which the abundance of deuterium is higher than that in nature. The perovskite film deposited using deuterated formamidine iodide as a raw material has enhanced stability. Therefore, the method can be used to prepare a perovskite solar cell with long-term stable operation.
[0045] The deuterated formamidine iodide used in this invention contains formamidine ions, and the deuterium isotope abundance of the four hydrogen atoms directly attached to the nitrogen atom reaches a level greater than 5%. For reference, the natural abundance of deuterium without any deuteration pretreatment is only 0.0157%. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Figure 1 This is a schematic diagram of a scanning electron microscope photograph of the perovskite light-absorbing layer obtained in the third step of Example 1.
[0047] Figure 2 It is the reaction between formamidine iodide and deuterated formamidine iodide. 1 Schematic diagram of H-NMR spectrum comparison.
[0048] Figure 3 This is a schematic diagram of the Fourier transform infrared spectrum image of the perovskite light-absorbing layer obtained in the third step of Example 1.
[0049] Figure 4 Schematic diagram of scanning electron microscope cross-sectional photographs of the perovskite solar cells prepared in Example 1 and Comparative Example 1 after 1000 h of aging.
[0050] Figure 5 Schematic diagram of the fluorescence spectrum changes of the perovskite solar cells prepared in Example 1 and Comparative Example 1 under long-term aging.
[0051] Figure 6 This is a schematic diagram of the current density-voltage curve obtained in the reverse scanning mode for the perovskite solar cell prepared in Example 1.
[0052] Figure 7 Schematic diagram of light stability test curves of perovskite solar cells prepared in Example 1 and Comparative Example 1. DETAILED DESCRIPTION
[0053] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.
[0054] Example 1
[0055] A method for enhancing the stability of a perovskite film comprises the following steps:
[0056] Step 1: Preparation of deuterated formamidine iodide
[0057] 1 g of formamidine iodide and heavy water were mixed at a molar ratio of 1:40, stirred overnight, and freeze-dried to remove water to obtain 1.02 g of deuterated formamidine iodide with a deuteration ratio of 90.4%.
[0058] The deuterium substitution ratio can be calibrated by nuclear magnetic resonance hydrogen spectrum. If there are higher requirements for the deuterium substitution ratio, multiple dissolution-freeze-drying operations can be performed.
[0059] Step 2: Preparation of hole transport layer
[0060] 0.3 mg of [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphoric acid (MeO-2PACz) was dissolved in 1 mL of ethanol to obtain a hole transport layer solution with a concentration of 0.3 mg / mL.
[0061] 45 mL of a hole transport layer solution with a concentration of 0.3 mg / mL was coated on an ITO substrate with a size of 1.3×1.5 cm. The solution was spin-coated at 3000 rpm for 30 seconds and heated at 100°C for 10 minutes to obtain a hole transport layer.
[0062] The third step is the preparation of the perovskite light absorbing layer
[0063] PbI2 (2 mmol, 922 mg), deuterated formamidine iodide (2 mmol, 352 mg), and methylamine hydrochloride (MACl) (0.2 mmol, 13.5 mg) were dissolved in 1 mL of DMF and DMSO (4:1 by volume). The film was spin-coated at 6000 rpm for 30 seconds on the hole-transport layer obtained in the second step. Chlorobenzene (CB) was used as an antisolvent and continuously flushed from directly above the film's center of rotation 10 seconds before the end of spin coating. After spin coating, the film was annealed in air at 150°C for 10 minutes, followed by another annealing at 100°C for 10 minutes to obtain the perovskite light-absorbing layer.
[0064] Step 4: Preparation of electron transport layer
[0065] The perovskite light absorbing layer obtained in the third step was cooled and 35 μL of 10 mg / mL electron transport layer material [6,6]-phenyl-C61-butyric acid methyl ester (PC 61 The perovskite solar cell was obtained by spin-coating 25 μL of 0.5 mg / mL 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) solution at 4000 rpm for 45 s, followed by heating at 70°C for 15 minutes. After cooling, a gold electrode was evaporated to obtain a perovskite solar cell.
[0066] Preparation of electron transport layer material solution: The electron transport layer material was dissolved in chlorobenzene to obtain an electron transport layer material solution with a concentration of 10 mg / mL.
[0067] Preparation of hole blocking layer material solution: The hole blocking layer material was dissolved in anhydrous ethanol to obtain a hole blocking layer material solution with a concentration of 0.5 mg / mL.
[0068] The perovskite solar cell prepared by the present invention has a structure, from bottom to top, comprising: a base layer, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, a hole blocking layer, and a back electrode. The glass substrate in the base layer is 1 mm thick, and the indium tin oxide conductive film is 500 nm thick. The hole transport layer is 50 nm thick, the perovskite light-absorbing layer is 600 nm thick, the electron transport layer is 20 nm thick, the hole blocking layer is 5 nm thick, and the gold electrode is 100 nm thick.
[0069] Comparative Example 1
[0070] According to the preparation method of Example 1, the perovskite light-absorbing layer in the third step was prepared, except that the deuterated formamidine iodide used was replaced with formamidine iodide, and the other conditions remained unchanged.
[0071] Example 2
[0072] According to the preparation method of Example 1, 0.3 mg of [2-(3,6-dimethoxy-9H-carbazol-9-yl)ethyl]phosphoric acid (MeO-2PACz) used in the second step of hole transport layer preparation was dissolved in 1 mL of ethanol. Instead, 0.5 mg of [2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl]phosphoric acid (Me-4PACz) was dissolved in 1 mL of ethanol to obtain a hole transport layer solution. Other conditions remained unchanged.
[0073] Example 3
[0074] The second step of preparing the hole transport layer was modified as follows: 1.5 mmol of nickel (II) acetate tetrahydrate and 0.075 mmol of strontium chloride hexahydrate were added to 5 mL of 2-methoxyethanol and stirred at 60 °C for 1 hour to form a uniform green solution. The solution was then allowed to stand at room temperature for 24 hours. The prepared solution was then plated on FTO conductive glass (purchased from Wuhan Jingge Solar Technology Co., Ltd., 14 Ω / m 2 The hole transport layer was obtained by spin coating on a glass substrate (length × width = 1.5 cm × 1.3 cm, glass substrate thickness 2 mm, conductive layer thickness 500 nm) at 3000 rpm for 30 seconds, followed by heating at 150°C for 5 minutes. The layer was cooled to room temperature and annealed at 500°C for 1 hour to obtain a hole transport layer. All other conditions were the same as in Example 1.
[0075] Figure 1 This is a schematic scanning electron microscope image of the perovskite light-absorbing layer obtained in the third step of Example 1. The SEM instrument model is HITACHI S4800. The control sample is the perovskite light-absorbing layer prepared with formamidine iodide in Example 1; the deuterated sample is the perovskite light-absorbing layer prepared with deuterated formamidine iodide in Example 1. As can be seen from the image, there is no significant difference in morphology between the deuterated formamidine iodide and the deuterated formamidine iodide.
[0076] Figure 2 It is the reaction between formamidine iodide and deuterated formamidine iodide. 1Schematic diagram of H-NMR hydrogen spectrum comparison. Among them, the control sample is the formamidine iodide of comparative example 1; the deuterated sample is the deuterated formamidine iodide prepared in Example 1. The test sample is a dispersed solution of formamidine iodide and deuterated formamidine iodide in deuterated DMSO. The test instrument used is Bruker Ascend 600MHz. As can be seen from the figure, the peak with a chemical shift of about 8.8 ppm represents the hydrogen atom directly connected to the nitrogen atom. After deuteration, the nuclear magnetic resonance peak of formamidine iodide at 8.8 ppm almost completely disappears. It should be pointed out that the nuclear magnetic resonance spectrum of the perovskite light-absorbing layer based on formamidine iodide in comparative example 1 can also observe a peak at about 7.9 ppm as the spectrum line in Example 1, which indicates that the hydrogen atoms directly adjacent to the carbon atoms are not replaced by deuterium atoms.
[0077] Figure 3 This is a schematic diagram of the Fourier transform infrared spectrum image of the perovskite light-absorbing layer obtained in the third step of Example 1. The instrument model used is Nicolet is50. Among them, the control sample is the perovskite light-absorbing layer prepared with formamidine iodide in Example 1; the deuterated sample is the perovskite light-absorbing layer prepared with deuterated formamidine iodide in Example 1. Comparing the two samples, it can be found that after deuteration, the sample has a higher wavelength at ~2500 cm -1 A significantly broadened vibration peak appeared at the position, corresponding to the ND bond produced after deuteration.
[0078] Figure 4 Schematic diagrams of scanning electron micrographs of cross-sections of perovskite solar cells prepared in Example 1 and Comparative Example 1 after 1000 hours of aging, using a HITACHI S4800 instrument. As can be seen, the non-deuterated control sample exhibits corrosion holes on the irradiated lower interface, while the deuterated sample remains flat.
[0079] Figure 5 The following diagram shows the fluorescence spectra of the perovskite solar cells prepared in Example 1 and Comparative Example 1 under long-term aging. The left image shows Comparative Example 1 as a standard sample, and the right image shows Example 1 as a deuterated sample. The fluorescence spectrophotometer used was a Fluorolog-3-p. As can be seen from the figure, the fluorescence spectrum of the standard sample undergoes a significant red shift after 1000 hours of aging, while the red shift of the deuterated sample is very weak, indicating that deuteration effectively inhibits the decomposition of the perovskite layer.
[0080] Figure 6 This is a schematic diagram of the current density-voltage curve of the perovskite solar cell prepared in Example 1, obtained in reverse scanning mode, with a photoelectric conversion efficiency of 25.08% and a short-circuit current of 25.24 mA·cm -2 , open circuit voltage 1.195 V, fill factor 0.831.
[0081] The perovskite solar cell prepared in Example 1 was tested under a solar simulator at 100 mW·cm -2 The photoelectric conversion efficiency was tested under standard light. The effective area of the cell is 0.0625 cm 2 .
[0082] The photoelectric conversion efficiency increased slightly from 24.95% to 25.08%.
[0083] Power conversion efficiency (PCE) is the most fundamental and core parameter for evaluating solar cells. It can be calculated from the current-voltage (IV) curve obtained by testing the cell under AM 1.5G standard solar irradiation conditions. The calculation formula is as follows:
[0084] Among them, P in Indicates the incident light power density (intensity of incident light). SC is the short-circuit photocurrent density, that is, the current density when the circuit is in a short-circuit state, at which time the battery voltage is 0 V. V OC is the open-circuit photovoltage, which is the potential difference across the battery measured when the battery is in the open circuit state. At this moment, the current flowing through the circuit is 0 A. FF is the fill factor, which is determined by the maximum power per unit area of the solar cell (P max ) divided by V OC and J SC The ratio is calculated and the value is within the range of 0 to 1. The FF calculation formula is as follows:
[0085] Photoelectric conversion efficiency is the most important parameter for evaluating the performance of solar cells. Before the test, a solar simulator (Solar IV-150A, Zolix) was used to simulate a standard sunlight AM 1.5G (100 mW·cm -2 ) was used as the light source to illuminate the solar cell. The light intensity was calibrated using a standard Newport calibrated KG5 filtered silicon reference cell before use. A Keithley 2400 digital source meter was used in a normal working environment at 0.15 V·s -1 The current density-voltage JV curve of the device was measured at a scan rate (voltage sweep range was -0.2 to 1.3 V with a step size of 10 mV). The active area of the device was limited to 0.0625 cm using a metal mask.2 .
[0086] Figure 7 Schematic diagram of the light stability test curve of the perovskite solar cells prepared in Example 1 and Comparative Example 1. The solar cells were placed in an environment with a light intensity of AM 1.5 G and a temperature of 55°C to test their stability. As can be seen from the figure, after 1264 hours of light exposure, the performance of the perovskite solar cell prepared in Example 1 only decayed by 3%, while the perovskite solar cell prepared in Comparative Example 1 decayed by 51.1%. From the above comparison, it can be seen that the performance of the perovskite solar cell prepared in the present invention is significantly better than that of the perovskite solar cell prepared in Comparative Example 1.
[0087] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present invention can make slight changes or modifications to equivalent embodiments using the above-mentioned technical contents without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the solution of the present invention.
Claims
1. A method for enhancing the stability of a perovskite film, characterized in that: The following steps are involved: In the first step, a hole transport layer solution with a concentration of 0.1-1 mg / mL is spin-coated on the substrate and heated to obtain a hole transport layer; The material of the hole transport layer is selected from [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphoric acid, [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphoric acid, [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, poly(3,4-ethylenedioxythiophene), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)]amine, poly-3-hexylthiophene, nickel oxide, and copper oxide; Alternatively, nickel acetate tetrahydrate and strontium chloride hexahydrate in a molar ratio of 1 to 50:1 are dissolved in 2-methoxyethanol, stirred at 50 to 70°C for 0.5 to 2 h, allowed to stand at room temperature for 1 to 24 h, spin-coated on a substrate, heated at 140 to 170°C for 1 to 10 minutes, cooled to room temperature, and annealed at 450 to 600°C for 0.5 to 2 h to obtain a hole transport layer; In the second step, PbI2, deuterated formamidine iodide, and methylamine hydrochloride at a molar ratio of 1:1:0.05-0.5 are dissolved in DMF and DMSO solvents and spin-coated on the obtained hole transport layer. The mixture is rinsed with an anti-solvent before the spin coating is completed. After the spin coating is completed, it is placed in air and annealed for the first time and then the second time to obtain a perovskite light-absorbing layer. In the third step, the perovskite light-absorbing layer is cooled, and an electron transport layer material solution with a concentration of 5 to 15 mg / mL is spin-coated. A hole blocking layer solution with a concentration of 0.1 to 1 mg / mL is then spin-coated. The solution is heated, cooled, and the electrode is evaporated to obtain a perovskite solar cell.
2. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The material of the substrate is selected from ITO substrate and FTO conductive glass; The hole transport layer solution is prepared by dissolving the hole transport layer material in ethanol to obtain a hole transport layer solution with a concentration of 0.1-1 mg / mL.
3. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The spin coating parameters in the first step were: 3000 rpm for 30 s; In the first step, a hole transport layer solution having a concentration of 0.1-1 mg / mL is spin-coated on the substrate and heated. The heating condition is: heating at a temperature of 90-110° C. for 5-20 minutes.
4. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The volume ratio of DMF and DMSO is 4:1; The spin coating parameters in the second step were: 6000 rpm for 30 s; In the second step, the anti-solvent rinsing time before the end of spin coating is 10 s.
5. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The anti-solvent is selected from chlorobenzene, toluene, and ethyl acetate; In the second step, the first annealing condition is: annealing at a temperature of 140-160° C. for 5-20 minutes; In the second step, the second annealing condition is: annealing is continued at a temperature of 90-110° C. for 5-20 minutes.
6. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The preparation method of the deuterated formamidine iodide comprises the following steps: mixing formamidine iodide and a deuterated reagent at a molar ratio of 1:1 to 60, stirring overnight, and freeze-drying to obtain the deuterated formamidine iodide.
7. The method for enhancing the stability of a perovskite film according to claim 6, wherein: The deuterated reagent is selected from heavy water, deuterated acetic acid, deuterated ethanol, deuterated formic acid, deuterated acetic acid, and deuterated ethylamine; In the third step, the heating conditions are: heating at a temperature of 60-80° C. for 5-20 minutes; Preparation of the electron transport layer material solution: dissolving the electron transport layer material in chlorobenzene to obtain an electron transport layer material solution with a concentration of 5-15 mg / mL.
8. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The material of the electron transport layer is selected from [6,6]-phenyl-C61-butyric acid methyl ester, [6,6]-phenyl-C71-butyric acid methyl ester, fullerene C60, fullerene C70, indene-C60 bisadduct; Preparation of the hole blocking layer solution: dissolving the hole blocking layer material in anhydrous ethanol to obtain a hole blocking layer material solution with a concentration of 0.1-1 mg / mL.
9. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The material of the hole blocking layer is selected from 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline; The back electrode is selected from a gold electrode.
10. The method for enhancing the stability of a perovskite film according to claim 1, wherein: The structure of the perovskite solar cell is as follows from bottom to top: substrate layer, hole transport layer, perovskite light absorbing layer, electron transport layer, hole blocking layer, and back electrode.