High-stability perovskite battery with top sprayed with hydrophobic layer and preparation method of high-stability perovskite battery

Abstract

The invention relates to the technical field of solar cells, in particular to a high-stability perovskite cell sprayed with a hydrophobic layer on the top and a preparation method of the high-stability perovskite cell. The cell comprises a conductive substrate, a hole transport layer, a perovskite light absorption layer, an interface modification layer, an electron transport layer, a hole barrier layer, a metal electrode layer and a hydrophobic protection film which are sequentially stacked from bottom to top, and the hydrophobic protection film is made of a polyfluoroalkyl substance. The super-hydrophobic protection film is formed on the surface of the perovskite solar cell, so that external moisture erosion is effectively blocked, ion diffusion between an electrode and perovskite is inhibited, and the stability of the device is remarkably improved. The film has excellent water repellency and corrosion resistance by means of extremely low surface energy and excellent chemical stability of the polyfluoroalkyl substance. The polyfluoroalkyl substance hydrophobic protection film provides a new thought for the research of improving the stability of the perovskite solar cell.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and more particularly to a highly stable perovskite solar cell with a top-sprayed hydrophobic layer and its preparation method. Background Technology

[0002] Energy is the driving force of economic development and an indispensable foundation for human survival. As history progresses, energy types have become increasingly diverse, and total demand continues to grow. Currently, the world's energy supply is still dominated by fossil fuels, including oil, coal, and natural gas. The reserves of these fossil fuels are dwindling, and the large amounts of pollutants and carbon dioxide generated during their use cause irreversible damage to the environment and climate. Renewable and clean energy, characterized by its renewability, lack of pollution, and safety, mainly includes ocean energy, wind energy, bioenergy, hydrogen energy, geothermal energy, and solar energy. Solar energy, as an inexhaustible and widely distributed renewable energy source, has become one of the most promising new energy sources due to its development not being geographically restricted. Solar cells, as the core device for photoelectric conversion, have laid an important foundation for developing a decarbonized economy and a sustainable energy system thanks to their mature technology, low cost, and ease of deployment.

[0003] Based on the development history of solar cells, they are generally divided into three generations: the first generation, silicon-based solar cells, are the most widely used, but suffer from high energy consumption and purification issues; the second generation, thin-film solar cells (such as GaAs and CdTe), are limited by the scarcity of raw materials, high costs, and pollution problems; the third generation, novel solar cells (such as dye-sensitized and organic cells), have developed rapidly due to their advantages of low cost and readily available raw materials. Among them, perovskite solar cells (ABX3 structure) are particularly outstanding, with their narrow bandgap, high light absorption coefficient, and excellent charge carrier transport characteristics making them ideal light-absorbing materials. In recent years, system improvements based on the composition and morphology of perovskite solar cells, combined with the development of novel charge transport materials, have resulted in a certification rate as high as 27%, showing great development potential. However, the long-term stability of perovskite solar cells under actual operating conditions remains a challenge that must be addressed.

[0004] The stability challenges of perovskite solar cells mainly stem from two aspects: the intrinsic properties of the materials and the device structure. From a materials perspective, the ionic crystal nature of perovskite results in weak structural bonds, making it susceptible to degradation under light, heat, electric fields, and water / oxygen environments. From a device perspective, interfacial reactions between metal electrodes and halogen components accelerate performance degradation. To address these issues, researchers have developed various strategies to improve stability. While precision encapsulation technologies such as atomic layer deposition (ALD) can significantly block water and oxygen, the complex processes increase manufacturing costs. The most common encapsulation process is vacuum lamination using photovoltaic-grade ethylene-vinyl acetate (EVA) encapsulation films. However, EVA inevitably decomposes under ultraviolet (UV) and high-temperature conditions, leading to the formation of small molecules such as acetic acid. This degradation causes the material to yellow and reduces its transparency. Therefore, developing a simple, efficient, and cost-effective stability improvement solution remains a key challenge for the industrialization of perovskite photovoltaic technology. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly stable perovskite solar cell with a top-sprayed hydrophobic layer and its preparation method. Based on the poor long-term stability of existing perovskite solar cells, this invention utilizes a solution prepared with hydrophobic materials to spray onto the surface of the perovskite solar cell, forming a hydrophobic protective film to improve the cell's stability. By selecting suitable hydrophobic materials and solvents, the perovskite cell is prevented from dissolving and a hydrophobic layer is formed, preventing harmful external molecules from diffusing into the device and inhibiting ion diffusion between the metal electrode and the perovskite, thereby improving the stability of the perovskite solar cell.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] The present invention provides a perovskite battery, the battery comprising, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an interface modification layer, an electron transport layer, a hole blocking layer, a metal electrode layer, and a hydrophobic protective film; the hydrophobic protective film is made of a polyfluoroalkyl substance.

[0008] Preferably, the polyfluoroalkyl substance includes one of perfluorocarboxylic acids, perfluorosulfonic acids, and perfluoroethers. Perfluorocarboxylic acids include, but are not limited to, perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA); perfluorosulfonic acids (PFSAs) include, but are not limited to, perfluorooctane sulfonic acid (PFOS) and perfluorohexane sulfonic acid (PFHxS); and perfluoroethers include, but are not limited to, hexafluoropropylene oxide dimers.

[0009] Preferably, the conductive substrate is made of either FTO glass or ITO glass.

[0010] The material of the interface modification layer is one of PEAI, PEABr, PEACl, PDADI, or PDADI+3MPTAI;

[0011] The electron transport layer is made of a fullerene derivative thin film.

[0012] The hole-blocking layer is made of one of the following: copper bath (BCP), lithium fluoride, and zinc oxide.

[0013] The material of the metal electrode layer is one of silver, copper, or gold.

[0014] Preferably, the hole transport layer is composed of NiO layers stacked sequentially from bottom to top. x The film consists of a thin film and a self-assembled monolayer of SAMs, wherein the material of the self-assembled monolayer of SAMs is one of 2PACz, Me-4PACz, MeO-2PACz, 4PADCB, and MeO-4PACz.

[0015] Preferably, the material of the perovskite light-absorbing layer is FA. x Cs 1-x PbI3, 0≤x≤1.

[0016] Another aspect of the present invention provides a method for preparing the above-mentioned perovskite solar cell, the method comprising the following steps:

[0017] 1) Clean the conductive substrate and prepare a dense and uniform hole transport layer on the conductive substrate using a spin coating process;

[0018] 2) The perovskite precursor solution was spin-coated onto the surface of the hole transport layer using an anti-solvent method, and then annealed to form a perovskite light-absorbing layer.

[0019] 3) An interface modification layer, an electron transport layer, and a hole blocking layer were sequentially prepared on the perovskite light-absorbing layer using a spin-coating process;

[0020] 4) A metal electrode layer is prepared on the hole-blocking layer using an evaporation method;

[0021] 5) Spray a polyfluoroalkyl substance solution onto the metal electrode layer to obtain a perovskite solar cell.

[0022] Preferably, in step 1), NiO is first spin-coated onto a conductive substrate. x Solution preparation of NiO x Thin film, in which NiO x The solution concentration was 10–20 mg / mL, the solvent was deionized water, the spin coating speed was 1000–5000 rpm, and the spin coating time was 5–30 s. Then, NiO... xSAMs self-assembled monolayers were prepared by spin-coating a SAMs solution onto a thin film. The concentration of the SAMs solution was 0.3–1.5 mg / mL, the solvent was ethanol, the spin-coating speed was 4000–5000 rpm, the spin-coating time was 30–50 s, the annealing temperature was 80–110 °C, and the annealing time was 10–30 min.

[0023] Preferably, in step 5), the solvent used for the polyfluoroalkyl substance solution is one of chlorobenzene, isopropanol, n-hexane, and n-butanol.

[0024] Preferably, in step 5), the concentration of the polyfluoroalkyl substance solution is 0.5–2 mg / mL.

[0025] Preferably, the hydrophobic protective film is prepared by spraying a polyfluoroalkyl substance solution onto the metal electrode using a spraying method, without annealing, and allowing it to air dry naturally.

[0026] The beneficial effects of this invention are as follows:

[0027] (1) For perovskite solar cells, efficiency and stability are important parameters for measuring cell quality. Currently, the stability requirements of perovskite cells have not been met, and the diffusion of molecules and ions can lead to irreversible degradation of photovoltaic device performance. This invention significantly improves device stability by forming a superhydrophobic protective film on the surface of the perovskite solar cell, effectively blocking external moisture erosion and inhibiting ion diffusion between the electrode and the perovskite. This film has excellent water resistance and corrosion resistance due to the extremely low surface energy and excellent chemical stability of polyfluoroalkyl substances. Specifically, polyfluoroalkyl substances are perfluorinated carbon chains in which all hydrogen atoms are replaced by fluorine atoms, which gives polyfluoroalkyl substances strong hydrophobicity and high stability. Polyfluoroalkyl substances can form a stable surface film, enhancing the waterproof performance of the material; and polyfluoroalkyl substances exhibit very low surface energy, allowing them to form a uniform and dense coverage on the surface of many materials, effectively protecting the substrate; the film formed by spraying polyfluoroalkyl substances acts as a strong hydrophobic barrier, which can not only prevent external water intrusion that leads to the decomposition of the perovskite solar cell, but also inhibit the halide-metal electrode reaction caused by molecular and ion migration.

[0028] (2) The present invention prepares an inverted perovskite solar cell. Compared with devices without a hydrophobic protective film, the inverted perovskite device based on a polyfluoroalkyl material layer does not show any decrease in power conversion efficiency and exhibits better stability.

[0029] (3) The method of the present invention is simple, requires no packaging, and has good repeatability, providing a new approach to improve the stability of perovskite solar cells. Attached Figure Description

[0030] Figure 1The water contact angles of the perovskite solar cell surfaces in Example 1 and Comparative Example 1 are shown, where a represents Comparative Example 1 and b represents Example 1.

[0031] Figure 2 Long-term stability testing of perovskite solar cells in Example 1 and Comparative Example 1;

[0032] Figure 3 Box plots showing the efficiency of the perovskite solar cells in Examples 1-4;

[0033] Figure 4 Box plots show the efficiency of perovskite solar cells in Examples 1 and 5-6. Detailed Implementation

[0034] The following examples are intended to provide a more comprehensive understanding of the present invention by those skilled in the art, but do not limit the invention in any way. Unless otherwise specified, the materials used in the embodiments of the present invention can be obtained commercially or prepared according to conventional methods well known to those skilled in the art.

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] The present invention provides a perovskite solar cell, comprising, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an interface modification layer, an electron transport layer, a hole blocking layer, a metal electrode layer, and a hydrophobic protective film stacked in sequence.

[0037] Preferably, the polyfluoroalkyl substance includes one of perfluorocarboxylic acids, perfluorosulfonic acids, and perfluoroethers. Perfluorocarboxylic acids include, but are not limited to, PFOA, PFNA, and PFDA; perfluorosulfonic acids include, but are not limited to, PFOS and PFHxS; and perfluoroethers include, but are not limited to, hexafluoropropylene oxide dimers.

[0038] The conductive substrate is made of either FTO glass or ITO glass.

[0039] The material of the interface modification layer is one of PEAI, PEABr, PEACl, PDADI, or PDADI+3MPTAI;

[0040] The electron transport layer is made of fullerene derivative thin films, such as PCBM;

[0041] The hole blocking layer is made of one of BCP, lithium fluoride, and zinc oxide.

[0042] The metal electrode layer is made of one of the following materials: silver, copper, or gold.

[0043] The hole transport layer consists of NiO layers stacked sequentially from bottom to top. xThe film consists of a thin film and a self-assembled monolayer of SAMs, wherein the material of the self-assembled monolayer of SAMs is one of 2PACz, Me-4PACz, MeO-2PACz, 4PADCB, and MeO-4PACz.

[0044] The material of the perovskite light-absorbing layer is FA. x Cs 1-x PbI3, 0≤x≤1;

[0045] The above-mentioned method for preparing perovskite solar cells includes the following steps:

[0046] Step 1: Clean the conductive substrate

[0047] The conductive substrate surface was first cleaned with detergent, then rinsed with deionized water, followed by three ultrasonic cleanings in alcohol for 20 minutes each, and then treated with ultraviolet-ozone for 15 minutes.

[0048] Step 2: Spin-coating a hole transport layer onto a conductive substrate.

[0049] At room temperature, by spin coating NiO x Ink, NiO x Thin films were deposited on a conductive substrate at a rotation speed of 1000–3000 rpm for 40–60 s without any heat treatment. Subsequently, the substrate was transferred to a glove box filled with N2, and the SAMs were dissolved in an ethanol solution on NiO. x Spin coating is performed at a speed of 3000-5000 rpm for 30-40 seconds. After spin coating, annealing is carried out at 100-110℃ for 5-10 minutes.

[0050] Step 3: Prepare a perovskite light-absorbing layer film on the hole transport layer film.

[0051] The perovskite precursor solution was prepared by one or more of FAI, PbI2, and CsI in a DMF:DMSO mixed solvent (4:1 / v:v). 17 mol% MACl and an excess of 12 mol% PbI2 were added to the precursor solution to improve the crystallization effect of the perovskite film. 50-80 μL of the precursor solution was spin-coated onto the hole transport layer using a pipette at a speed of 1000-5000 rpm for 5-30 s. 150-200 μL of the anti-solvent chlorobenzene was dropped onto the rotating perovskite layer in the last 10-15 s. Finally, the perovskite was annealed at 80-110 °C for 10-30 min.

[0052] Step 4: Prepare an electron transport layer film on the perovskite light-absorbing layer film.

[0053] The electron transport layer material was dissolved in chlorobenzene at a concentration of 10–20 mg / mL and spin-coated onto the perovskite light-absorbing layer to form the electron transport layer. The spin-coating speed was 4000–5000 rpm and the spin-coating time was 30–50 s.

[0054] Step 5: Fabricate a hole blocking layer on the electron transport layer thin film.

[0055] The hole blocking layer material was dissolved in isopropanol solvent to obtain a saturated solution. The solution was then placed at room temperature and stirred for 24 hours. The filtered solution was spin-coated onto the surface of the electron transport layer to form a hole blocking layer.

[0056] Step 6: Fabricate a metal electrode on the hole blocking layer.

[0057] The perovskite solar cell is placed in a specific photomask, which is then placed in a metal evaporation device. A vacuum is initially created, and once the appropriate vacuum level is reached, metal evaporation begins at an evaporation rate of [missing information]. The evaporation thickness is 80–180 nm;

[0058] Step 7: Spray a hydrophobic protective film onto the metal electrode.

[0059] The polyfluoroalkyl substance is dissolved in a solvent to obtain a polyfluoroalkyl substance solution with a concentration of 0.5-2 mg / mL. The polyfluoroalkyl substance solution is then sprayed onto the metal electrode by a spraying method, without annealing, and allowed to air dry naturally.

[0060] The perovskite solar cell described above will be further described in detail below with reference to several specific embodiments.

[0061] Example 1

[0062] The inverse perovskite solar cell provided in this embodiment is prepared by the following steps:

[0063] (1) The surface of the ITO glass substrate was first cleaned with detergent, then rinsed with deionized water, and then the substrate was ultrasonically cleaned three times in alcohol for 20 minutes each time. Finally, the substrate was treated with ultraviolet-ozone for 15 minutes.

[0064] (2) At room temperature, NiO was spin-coated x Ink, raw NiO x Thin films were deposited on the substrate at 1000–3000 rpm for 40–60 s without any heat treatment. The substrate was then transferred to a glove box filled with N2. 4PADCB was dissolved in an ethanol solution on NiO. x Spin coating is performed at a speed of 3000-5000 rpm for 30-40 seconds. After spin coating, annealing is carried out at 100-110℃ for 5-10 minutes.

[0065] (3) The perovskite precursor is FA 0.95 Cs 0.05 PbI3 was prepared in a DMF:DMSO mixed solvent (4:1 / v:v). 17 mol% MACl and an excess of 12 mol% PbI2 were added to the precursor solution to improve the crystallization effect of the perovskite film. 50-80 μL of the precursor solution was spin-coated onto the hole transport layer using a pipette at a speed of 1000-5000 rpm for 5-30 s. 150-200 μL of the antisolvent chlorobenzene was dropped onto the rotating perovskite layer in the last 10-15 s. Finally, the perovskite layer was annealed at 80-110 °C for 10-30 min.

[0066] (4) Dissolve PCBM in chlorobenzene at a concentration of 10-20 mg / mL and spin-coat it onto the perovskite light-absorbing layer to form an electron transport layer. The spin-coating speed is 4000-5000 rpm and the spin-coating time is 30-50 s.

[0067] (5) Dissolve BCP in isopropanol solvent to obtain a saturated BCP solution. Then, place the BCP solution at room temperature and shake and stir for 24 hours. Spin-coat the filtered BCP solution onto the surface of the electron transport layer to form a hole blocking layer.

[0068] (6) Place the perovskite solar cell in a specific mask, place the mask in a metal evaporation device to evaporate the silver electrode, start evaporating a vacuum, and once a suitable vacuum level is reached, begin metal evaporation at an evaporation rate of [missing information]. The evaporation thickness is 80–180 nm;

[0069] (7) Dissolve the polyfluoroalkyl substance in n-butanol to obtain a polyfluoroalkyl substance solution, and spray it onto the perovskite solar cell. The concentration of the polyfluoroalkyl substance solution is 1 mg / mL, and a perovskite solar cell with a hydrophobic protective film sprayed on the top is obtained.

[0070] Example 2

[0071] This embodiment uses the same method as in Example 1 to prepare perovskite batteries, except that the concentration of the polyfluoroalkyl substance solution in step (7) is 0.5 mg / mL.

[0072] Example 3

[0073] This embodiment uses the same method as Example 1 to prepare perovskite batteries, except that the concentration of the polyfluoroalkyl substance solution in step (7) is 1.5 mg / mL.

[0074] Example 4

[0075] This embodiment uses the same method as in Example 1 to prepare perovskite batteries, except that the concentration of the polyfluoroalkyl substance solution in step (7) is 2 mg / mL.

[0076] Example 5

[0077] This embodiment uses the same method as Example 1 to prepare perovskite solar cells, except that the solvent in step (7) is isopropanol.

[0078] Example 6

[0079] This embodiment uses the same method as Example 1 to prepare perovskite batteries, except that the solvent in step (7) is n-hexane.

[0080] Comparative Example 1

[0081] The fabrication method of a primitive perovskite solar cell includes the following steps:

[0082] (1) The surface of the ITO glass substrate was first cleaned with detergent, then rinsed with deionized water, and then the substrate was ultrasonically cleaned three times in alcohol for 20 minutes each time. Finally, the substrate was treated with ultraviolet-ozone for 15 minutes.

[0083] (2) At room temperature, NiO was spin-coated x Ink, raw NiO x Thin films were deposited on the substrate at a rotation speed of 1000–3000 rpm for 40–60 s without any heat treatment. Subsequently, the substrate was transferred to a glove box filled with N2, and 4PADCB was dissolved in an ethanol solution on NiO. x Spin coating is performed at a speed of 3000-5000 rpm for 30-40 seconds. After spin coating, annealing is carried out at 100-110℃ for 5-10 minutes.

[0084] (3) The perovskite precursor is FA 0.95 Cs 0.05 PbI3 was prepared in a DMF:DMSO mixed solvent (4:1 / v:v). 17 mol% MACl and an excess of 12 mol% PbI2 were added to the precursor solution to improve the crystallization effect of the perovskite film. 50-80 μL of the precursor solution was spin-coated onto the hole transport layer using a pipette at a speed of 1000-5000 rpm for 5-30 s. 150-200 μL of the antisolvent chlorobenzene was dropped onto the rotating perovskite layer in the last 10-15 s. Finally, the film was annealed at 80-110 °C for 10-30 min.

[0085] (4) Dissolve PCBM in chlorobenzene at a concentration of 10-20 mg / mL and spin-coat it onto the perovskite light-absorbing layer to form an electron transport layer. The spin-coating speed is 4000-5000 rpm and the spin-coating time is 30-50 s.

[0086] (5) Dissolve BCP in isopropanol solvent to obtain a saturated BCP solution. Then, place the BCP solution at room temperature and shake and stir for 24 hours. Spin-coat the filtered BCP solution onto the surface of the electron transport layer to form a hole blocking layer.

[0087] (6) Place the perovskite solar cell in a specific mask, place the mask in a metal evaporation device to evaporate the silver electrode, start evaporating a vacuum, and once a suitable vacuum level is reached, begin metal evaporation at an evaporation rate of [missing information]. Perovskite solar cells were obtained by evaporating a thickness of 80–180 nm.

[0088] Comparative Example 2

[0089] This comparative example uses the same method as Example 1 to prepare perovskite solar cells. The difference is that the hydrophobic protective film material in step (7) is polydimethylsiloxane. Specifically, polydimethylsiloxane is dissolved in n-butanol and fully dissolved to obtain a polydimethylsiloxane solution, which is then sprayed onto the perovskite solar cell. The concentration of polydimethylsiloxane is 1 mg / mL.

[0090] The hydrophobic layer prepared using this material has high viscosity and is not easy to flow, so it cannot cover the silver electrode well. Moreover, the excessive thickness of the coating hinders the transport performance of the silver electrode.

[0091] Results analysis:

[0092] like Figure 1 As shown, the contact angles of the original and Example 1 perovskite devices coated with polyfluoroalkyl materials were tested. The contact angle of the perovskite device coated with polyfluoroalkyl materials was calculated to be 92.4°, which is greater than the 76.4° of the original perovskite device. The increase in water contact angle indicates that the water-resistant capability of the perovskite device coated with polyfluoroalkyl materials is improved, which will be beneficial to the long-term stability of perovskite solar cells.

[0093] like Figure 2 As shown, under the long-term stability test (SIOS-D-1) conducted at room temperature without humidity control, the device coated with polyfluoroalkyl materials exhibited excellent stability, maintaining about 90% of the original PCE within 2000 hours, while the perovskite solar cell of Comparative Example 1 rapidly decreased to 47% of the original value within 1200 hours. Figure 2The inset shows images of the control and target devices after 80 days. It is clearly observable that the Comparative Example 1 sample exhibits significant discoloration in the area covered by the Ag electrode, while the target sample shows only slight discoloration at the edge of the Ag electrode. This indicates that polyfluoroalkyl materials can effectively protect perovskite solar cells, especially at the boundary of the Ag electrode. Spraying polyfluoroalkyl materials can inhibit the intrusion of water and oxygen, thereby enhancing the stability of perovskite solar cells.

[0094] like Figure 3 As shown, box plots of efficiency of polyfluoroalkyl substances at different concentrations in n-butanol were compared. The results showed that the perovskite solar cell with 1 mg / mL polyfluoroalkyl compound had the highest efficiency.

[0095] like Figure 4 As shown, a box plot comparing the efficiency of perovskite solar cells with different solvents for dissolving polyfluoroalkyl substances was presented, revealing that perovskite solar cells using n-butanol as the solvent had the highest efficiency.

[0096] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the implementation. The scope of protection of the present invention should be determined by the scope defined in the claims. Other variations or modifications can be made based on the above description. Obvious variations or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A perovskite solar cell, characterized in that, The battery comprises, from bottom to top, a conductive substrate, a hole transport layer, a perovskite light-absorbing layer, an interface modification layer, an electron transport layer, a hole blocking layer, a metal electrode layer, and a hydrophobic protective film, stacked sequentially. The hydrophobic protective film is made of polyfluoroalkyl substances.

2. The perovskite solar cell according to claim 1, characterized in that, The polyfluoroalkyl substances include one of perfluorocarboxylic acids, perfluorosulfonic acids, and perfluoroethers.

3. The perovskite solar cell according to claim 1, characterized in that, The conductive substrate is made of either FTO glass or ITO glass. The material of the interface modification layer is one of PEAI, PEABr, PEACl, PDADI, or PDADI+3MPTAI; The electron transport layer is made of a fullerene derivative thin film. The hole-blocking layer is made of one of the following: copper bath compound, lithium fluoride, and zinc oxide. The material of the metal electrode layer is one of silver, copper, or gold.

4. The perovskite solar cell according to claim 1, characterized in that, The hole transport layer is composed of NiO layers stacked sequentially from bottom to top. x The film consists of a thin film and a self-assembled monolayer of SAMs, wherein the material of the self-assembled monolayer of SAMs is one of 2PACz, Me-4PACz, MeO-2PACz, 4PADCB, and MeO-4PACz.

5. The perovskite solar cell according to claim 1, characterized in that, The perovskite light-absorbing layer is made of FA. x Cs 1- x PbI3, 0≤x≤1.

6. A method for preparing a perovskite solar cell according to any one of claims 1-5, characterized in that, The method includes the following steps: 1) Clean the conductive substrate and prepare a dense and uniform hole transport layer on the conductive substrate using a spin coating process; 2) The perovskite precursor solution was spin-coated onto the surface of the hole transport layer using an anti-solvent method, and then annealed to form a perovskite light-absorbing layer. 3) An interface modification layer, an electron transport layer, and a hole blocking layer were sequentially prepared on the perovskite light-absorbing layer using a spin-coating process; 4) A metal electrode layer is prepared on the hole-blocking layer using an evaporation method; 5) Spray a polyfluoroalkyl substance solution onto the metal electrode layer to obtain a perovskite solar cell.

7. The preparation method according to claim 6, characterized in that, In step 1), NiO is first spin-coated onto the conductive substrate. x Solution preparation of NiO x Thin film, in which NiO x The solution concentration was 10–20 mg / mL, the solvent was deionized water, the spin coating speed was 1000–5000 rpm, and the spin coating time was 5–30 s. Then, NiO... x SAMs self-assembled monolayers were prepared by spin-coating a SAMs solution onto a thin film. The concentration of the SAMs solution was 0.3–1.5 mg / mL, the solvent was ethanol, the spin-coating speed was 4000–5000 rpm, the spin-coating time was 30–50 s, the annealing temperature was 80–110 °C, and the annealing time was 10–30 min.

8. The preparation method according to claim 6, characterized in that, In step 5), the solvent used for the polyfluoroalkyl substance solution is one of chlorobenzene, isopropanol, n-hexane, and n-butanol.

9. The preparation method according to claim 6, characterized in that, In step 5), the concentration of the polyfluoroalkyl substance solution is 0.5–2 mg / mL.

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