Perovskite solar cell based on double-site passivator and preparation method thereof

Abstract

The invention discloses a perovskite solar cell based on a double-site passivator and a preparation method thereof, a perovskite photovoltaic device based on the double-site passivator comprises a perovskite light absorption layer, and the perovskite light absorption layer comprises the double-site passivator. According to the invention, the selected double-site passivator can adopt parallel arrangement binding orientation in perovskite, so that strong coordination with two adjacent under-coordination Pb < 2 + > defect sites can be realized. Through the double-site passivator, the grain size of perovskite is remarkably increased, the crystal quality of the perovskite thin film is improved, the defect density of the perovskite thin film is reduced, the uniformity and the photoelectric property of the perovskite thin film are improved, and the photoelectric conversion efficiency of the perovskite solar cell based on the double-site passivator is remarkably improved and can reach 26.51% to the maximum.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar cells, and in particular to a perovskite solar cell based on a double-site passivation agent and a preparation method thereof. BACKGROUND

[0002] Perovskite solar cells (PSCs) as a new photovoltaic device have achieved a leapfrog development in efficiency in the past decade - the photoelectric conversion efficiency (PCE) was only 3.8% when first reported in 2009, and has increased to 27.0% by 2025, close to the level of traditional crystalline silicon cells. This breakthrough is due to the unique ABX3 crystal structure of perovskite materials (A site is an organic / inorganic cation such as methylamine ion, B site is a metal ion such as lead, and X site is a halide anion) and its excellent photoelectric properties, such as high light absorption coefficient, long carrier diffusion length, adjustable band gap and low non-radiative recombination rate. In terms of preparation process, the solution method adopted by it can be crystallized at low temperature, with the advantages of simple process, low cost and adaptation to flexible substrate, providing a basis for industrial application.

[0003] Currently, the solution method is the core technology for preparing perovskite thin films, but due to the fast evaporation of solvents and the complex reaction of precursors, it is difficult to control the crystallization process of the thin film, which easily produces uneven grain size and grain boundaries, point defects and other intrinsic defects, thereby reducing the carrier migration efficiency, increasing the non-radiative recombination and affecting the device performance. To solve this problem, researchers have proposed additive engineering strategies such as metal ions, ionic liquids, polymers and organic small molecules. Among them, metal ion additives can passivate iodine ions and Pb 0 , I 0 defects, but there are problems of uneven distribution and migration under electric field; ionic liquid additives can passivate defects through anion-cation coordination, but they may be incompatible with precursors or residual affect carrier transport; polymer additives can regulate crystallization kinetics and passivate bulk defects, but their long molecular chains can easily lead to uneven distribution and insulating properties affecting carrier transport; organic small molecule additives can passivate defect sites through functional groups and regulate crystallization, but the effect of traditional single active site passivation agents is limited, making it difficult to fully improve the device performance and stability.

[0004] In the prior art, the non-radiative recombination increase and the thin film quality decrease caused by perovskite thin film defects (especially uncoordinated Pb 2+ ions), as well as the limitations of traditional single active site passivation agents, have become key problems that restrict the photoelectric conversion efficiency and long-term stability of the device. Therefore, developing functionalized additives with multiple active sites to solve the above defect problems through synergistic passivation is an important direction to improve the performance of perovskite solar cells. SUMMARY

[0005] To solve the above technical problems, the primary object of the present application is to provide a perovskite solar cell based on a double-site passivation agent.

[0006] Another object of the present application is to provide a preparation method of a perovskite solar cell based on a double-site passivation agent.

[0007] The present application is realized by the following technical solutions:

[0008] A perovskite solar cell based on a double-site passivation agent, comprising a perovskite light absorption layer, wherein the perovskite light absorption layer comprises a double-site passivation agent selected from one or more of the following structural formulas:

[0009]

[0010] wherein R1 and R2 are different, and each of R1 and R2 is independently selected from one of a sulfonamide group, an amide group, an ester group, an aldehyde group, a hydroxyl group, a carboxyl group and a cyano group.

[0011] The double-site passivation agent selected by the present application can adopt a parallel arrangement combined orientation in the perovskite, thereby being capable of strongly coordinating with two adjacent under-coordinated Pb 2+ defect sites. This double-site passivation agent capable of more strongly coordinating with under-coordinated Pb 2+ The double-site passivation agent capable of more strongly coordinating with under-coordinated Pb

[0012] Further, each of R1 and R2 is independently selected from one of a sulfonamide group, a hydroxyl group, a carboxyl group and a cyano group.

[0013] Further, R1 or R2 is a sulfonamide group.

[0014] Further, the double-site passivation agent is selected from one or more of 4-hydroxybenzenesulfonamide, 4-cyanobenzenesulfonamide, 4-carboxybenzenesulfonamide, 4-formamidobenzoic acid, 1,4-benzenedicarboxylic acid dimethyl ester, 4-(methoxycarbonyl)benzoic acid, 4-formylbenzoic acid methyl ester, 4-nitrilebenzamide, 5-cyano-2-pyridinecarboxamide, 6-carbomoyl nicotinic acid methyl ester, 6-aminocarbonylpyridine-3-carboxylic acid, 6-aminosulfonyl nicotinic acid, 6-aminosulfonyl-nicotinic acid methyl ester, 5-formylpyridine-2-sulfonamide, 5-cyanopyridine-2-sulfonamide, 5-cyanopyridine-2-carboxylic acid, 5-cyano-pyridine-2-carboxylic acid methyl ester, pyrazine-2,5-dicarboxylic acid diethyl ester, 5-(methoxycarbonyl)pyrazine-2-carboxylic acid, pyrazine-2,5-dicarboxylic acid dimethyl ester, 5-(aminocarbonyl)-2-pyrazinecarboxylic acid and 5-cyano-2-pyrazine sulfonamide.

[0015] Preferably, the double-site passivator is selected from one or more of 4-hydroxybenzenesulfonamide, 4-cyanobenzenesulfonamide and 4-carboxybenzenesulfonamide.

[0016] Further, the perovskite solar cell based on double-site passivator comprises an anode substrate, a hole transport layer, a perovskite light absorption layer, a perovskite passivation layer, an electron transport layer, a perovskite protective layer and a cathode electrode arranged in sequence on one side of the anode substrate.

[0017] Further, the anode substrate comprises fluorine-doped tin oxide (FTO) glass; the material of the hole transport layer comprises (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl) phosphonic acid (Me-4PACz); the material of the perovskite passivation layer comprises phenethylamine hydroiodide (PEAI); the material of the electron transport layer comprises fullerene derivatives such as ICBA, PCBM, C60, etc.; the material of the perovskite protective layer comprises SnO x , wherein 0 < x ≤ 2; the cathode electrode comprises a silver (Ag) electrode.

[0018] Further, the perovskite solar cell based on double-site passivator has a photoelectric conversion efficiency higher than 23%.

[0019] Preferably, the perovskite solar cell based on double-site passivator has a photoelectric conversion efficiency higher than 25%.

[0020] More preferably, the perovskite solar cell based on double-site passivator has a photoelectric conversion efficiency higher than 26%.

[0021] A preparation method of the perovskite solar cell based on double-site passivator described above, comprising the following steps:

[0022] S1. Preparing a hole transport layer on an anode substrate;

[0023] S2. Dissolving cesium chloride (CsCl), methylammonium iodide (MAI), formamidinium iodide (FAI), lead iodide (PbI2) and methylammonium chloride (MACl) in an organic solvent to react, obtaining a perovskite precursor solution; adding a double-site passivator to the perovskite precursor solution to obtain a perovskite solution, and coating the perovskite solution on the hole transport layer prepared in S1 to obtain a perovskite light absorption layer;

[0024] S3. Preparing a perovskite passivation layer on the perovskite light absorption layer prepared in S2;

[0025] S4. Preparing an electron transport layer on the perovskite passivation layer prepared in S3;

[0026] S5. Preparing a perovskite protective layer on the electron transport layer prepared in S4;

[0027] S6. Preparing a cathode electrode on the perovskite protective layer prepared in S5 to obtain the perovskite solar cell based on the dual-site passivator.

[0028] Further, in S1, the anode substrate comprises FTO glass.

[0029] Further, the FTO glass is cleaned, and the cleaned FTO glass is dried before being subjected to ultraviolet treatment.

[0030] In the specific embodiment, the FTO glass surface is wiped with glass cleaning powder to remove particulate matter and oil stains, and the FTO glass is sequentially placed in deionized water, deionized water, acetone and ethanol to which glass cleaning agent is added for ultrasonic cleaning, with each step of cleaning lasting for 20-40 minutes. The glass surface is blown dry with a nitrogen gun to ensure that there is no water stain or particle residue. The dried FTO glass is placed in an ultraviolet ozone cleaning machine for 20-30 minutes to improve the surface wettability.

[0031] Further, in S1, the preparation of the hole transport layer comprises the following steps: spin coating a hole transport layer solution on the anode substrate at a rotation speed of 2500-3500 rpm for 25-35 s, and then annealing at 90-110°C for 5-15 min to obtain the hole transport layer.

[0032] Further, in S1, the material of the hole transport layer comprises Me-4PACz.

[0033] Further, in S1, the hole transport layer solution is a Me-4PACz solution, and the concentration of Me-4PACz in the Me-4PACz solution is 0.4-0.8 mg / mL.

[0034] Further, in S2, the concentration of the dual-site passivator in the perovskite solution is 0.1-4 mg / mL, preferably 0.25-2 mg / mL, and more preferably 0.5-1 mg / mL.

[0035] Further, in S2, the organic solvent is dimethylformamide (DMF) and / or dimethyl sulfoxide (DMSO); when DMF and DMSO are used as mixed solvents, the volume ratio of DMF to DMSO is 4:1.

[0036] In the specific embodiment, in S2, a two-step spin coating process is used to deposit the perovskite light absorption layer, and chlorobenzene (CB) is added dropwise as an anti-solvent during the spin coating process.

[0037] Further, in S2, the perovskite solution is spin coated on the hole transport layer, and the perovskite light absorption layer is obtained after annealing.

[0038] Further, the specific operation of the spin coating is as follows: accelerating at an acceleration of 150-250 rpm / s for 6-16 s to a rotation speed of 1500-2500 rpm for one-step spin coating, then accelerating at an acceleration of 1500-2500 rpm / s for 1-3 s to a rotation speed of 3500-4500 rpm for two-step spin coating, adding the anti-solvent at the 15-25 s after the start of the two-step spin coating, and ending the spin coating after continuing to spin for 10-15 s.

[0039] Further, the specific operation of the annealing treatment is as follows: sequentially performing annealing treatment at 60-80 ℃ for 5-15 min, at 90-110 ℃ for 50-70 min, and at 140-160 ℃ for 5-15 min.

[0040] Further, in S3, the perovskite passivation layer solution is spin-coated on the perovskite light absorption layer at a rotation speed of 2500-3500 rpm for 20-40 s, and the perovskite passivation layer is obtained after annealing treatment at 80-100 ℃ for 3-7 min.

[0041] Further, in S3, the material of the perovskite passivation layer includes PEAI.

[0042] Further, in S3, the perovskite passivation layer solution is a PEAI solution, the PEAI solution is prepared by dissolving PEAI in isopropyl alcohol, and the concentration of PEAI in the PEAI solution is 0.4-0.8 mg / mL.

[0043] Further, in S4, the electron transport layer is deposited by a high-vacuum evaporation method.

[0044] Further, in S4, the material of the electron transport layer includes a fullerene derivative, such as ICBA, PCBM, C60, etc.

[0045] Further, in S4, the thickness of the electron transport layer is 20-30 nm.

[0046] Further, in S5, the perovskite protection layer is deposited by an atomic deposition method (ALD).

[0047] Further, in S5, the material of the perovskite protection layer includes SnO x , wherein 0 < x ≤ 2.

[0048] Further, in S5, the thickness of the perovskite protection layer is 10-15 nm.

[0049] Further, in S6, the cathode electrode is deposited by an evaporation method.

[0050] Further, in S5, the material of the cathode electrode includes an Ag electrode.

[0051] Further, in S5, the thickness of the cathode electrode is 180-220 nm.

[0052] Compared with the prior art, the present application has the following beneficial effects:

[0053] 1. The present application selects a double-site passivation agent as a functional additive, wherein the pi conjugated structure of the benzene ring helps to promote charge transfer, and its planar structure can be arranged in parallel on the perovskite surface to enhance the passivation effect; at the same time, the sulfonamide group forms a strong coordination bond with uncoordinated Pb 2+ ions in perovskite, thereby effectively passivating surface defects. In addition, the lone pair of electrons in the functional group (such as carboxyl and cyano) can form a strong coordination bond with the defect sites in perovskite, further improving the passivation efficiency.

[0054] 2. The present application significantly increases the perovskite grain size by using a double-site passivation agent, improves the crystalline quality of the perovskite thin film and reduces its defect density, improves the uniformity and photoelectric performance of the perovskite thin film, and the photoelectric conversion efficiency of the perovskite solar cell based on the double-site passivation agent is significantly improved, which can be as high as 26.51%. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is the SEM graph of the perovskite light absorption layer in Example 2, Example 6, Example 10 and Comparative Example 1; wherein (a) is the surface SEM graph of Comparative Example 1, (b) is the surface SEM graph of Example 2, (c) is the surface SEM graph of Example 6, (d) is the surface SEM graph of Example 10, (e) is the cross-sectional SEM graph of Comparative Example 1, (f) is the cross-sectional SEM graph of Example 2, (g) is the cross-sectional SEM graph of Example 6, and (h) is the cross-sectional SEM graph of Example 10.

[0056] Figure 2 It is the AFM graph of the perovskite light absorption layer in Example 2, Example 6, Example 10 and Comparative Example 1; wherein (a) is Comparative Example 1, (b) is Example 2, (c) is Example 6, and (d) is Example 10.

[0057] Figure 3 It is the XRD graph of the perovskite light absorption layer in Example 2, Example 6, Example 10 and Comparative Example 1.

[0058] Figure 4 It is a simulation result graph of the passivation agent in Example 6, Example 10 and Comparative Example 2 on the perovskite surface based on the first principle calculation of DFT; wherein (a) is Example 6, (b) is Example 10, and (c) is Comparative Example 2.

[0059] Figure 5UV-Vis absorption spectra (left) and band gap spectra (right) of the perovskite light absorbing layer in Example 2, Example 6, Example 10 and Comparative Example 1.

[0060] Figure 6 PL spectra (left) and TRPL spectra (right) of the perovskite solar cells in Example 2, Example 6, Example 10 and Comparative Example 1.

[0061] Figure 7 J-V curve of the perovskite solar cells in Example 1-4 and Comparative Example 1.

[0062] Figure 8 J-V curve of the perovskite solar cells in Example 5-8 and Comparative Example 1.

[0063] Figure 9 J-V curve of the perovskite solar cells in Example 9-12 and Comparative Example 1.

[0064] Figure 10 Positive and negative scan curve of the perovskite solar cells in Example 2, Example 6, Example 10 and Comparative Example 1.

[0065] Figure 11 Space charge limited current (SCLC) curve of the perovskite solar cells in Example 2, Example 6, Example 10 and Comparative Example 1; wherein (a) is Comparative Example 1, (b) is Example 2, (c) is Example 6, (d) is Example 10. DETAILED DESCRIPTION

[0066] Unless otherwise defined, 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 belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0067] The present application will be further described with reference to the drawings and specific examples in which the following examples are presented as examples of the application. The examples are not intended to limit the application.

[0068] The experimental methods used in the following examples and comparative examples are conventional unless otherwise stated, and the materials, reagents, etc. used are commercially available unless otherwise stated.

[0069] Example 1

[0070] A perovskite solar cell based on OH-BSA, comprising FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode arranged in sequence on one side of the FTO glass.

[0071] The preparation method of the perovskite solar cell based on OH-BSA of Example 1 comprises the following steps:

[0072] S1. Preparing a Me-4PACz layer on FTO glass: wipe the surface of the FTO glass with a glass cleaning powder to remove particulate matter and oil stains, and sequentially ultrasonic clean the FTO glass in deionized water, deionized water, acetone and ethanol with glass cleaning agent added, each for 30 minutes. Dry the glass surface with a nitrogen gun to ensure that there is no water stain or particle residue. Place the dried FTO glass in an ultraviolet ozone cleaning machine for 20 minutes to improve the surface wettability. Drop 150 μL of Me-4PACz solution with a concentration of 0.5 mg / mL on the surface of the FTO glass, spin at a speed of 3000 rpm for 30 s, and then anneal at 100°C for 10 min to obtain the Me-4PACz layer.

[0073] S2. Preparing a perovskite light absorption layer on the Me-4PACz layer: dissolve CsCl (0.065M), MAI (0.065M), FAI (1.17M), PbI2 (1.365M) and MACl (0.26M) in a mixed solvent of DMF and DMSO with a volume ratio of 4:1 to obtain a perovskite precursor solution; add OH-BSA to the perovskite precursor solution to obtain a perovskite solution, and the concentration of OH-BSA in the perovskite solution is 0.25 mg / mL; spin 80 μL of the perovskite solution on the hole transport layer at an acceleration of 200 rpm / s for 10 s to a speed of 2000 rpm for one-step spinning, then accelerate at an acceleration of 2000 rpm / s for 2 s to a speed of 4000 rpm for two-step spinning, drop 200 μL of CB at the 20th second after the start of two-step spinning, continue to spin for 10 s, and then end the spinning, and sequentially anneal at 70°C for 10 min, at 100°C for 60 min, and at 150°C for 10 min to obtain the perovskite light absorption layer.

[0074] S3. Preparing a PEAI layer on the perovskite light absorption layer: spin the PEAI solution (concentration 5 mg / mL, solvent isopropanol) at a speed of 3000 rpm on the perovskite light absorption layer for 30 s, and then anneal at 90°C for 5 min to obtain the PEAI layer.

[0075] S4. A 25 nm layer of C60 is deposited on the PEAI layer by a high vacuum evaporation method.

[0076] S5. A 10 nm layer of SnO2 is deposited on the C60 layer using an atomic deposition method. x layer;

[0077] S6. A 200 nm Ag electrode is deposited on the SnO2 layer by an evaporation method to obtain the OH-BSA-based perovskite solar cell. x

[0078] Example 2

[0079] An OH-BSA-based perovskite solar cell includes an FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO2 layer and an Ag electrode arranged in sequence on one side of the FTO glass, and the preparation method is basically the same as that of Example 1, except that in S2, the concentration of OH-BSA in the perovskite solution is 0.50 mg / mL. x

[0080] Example 3

[0081] An OH-BSA-based perovskite solar cell includes an FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO2 layer and an Ag electrode arranged in sequence on one side of the FTO glass, and the preparation method is basically the same as that of Example 1, except that in S2, the concentration of OH-BSA in the perovskite solution is 1.00 mg / mL. x

[0082] Example 4

[0083] An OH-BSA-based perovskite solar cell includes an FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO2 layer and an Ag electrode arranged in sequence on one side of the FTO glass, and the preparation method is basically the same as that of Example 1, except that in S2, the concentration of OH-BSA in the perovskite solution is 2.00 mg / mL. x

[0084] Example 5

[0085] A CN-BSA-based perovskite solar cell includes an FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO2 layer and an Ag electrode arranged in sequence on one side of the FTO glass. x

[0086] ​​​​​The preparation method of the perovskite solar cell based on CN-BSA of Example 5 comprises the following steps:

[0087] S1. Preparing Me-4PACz layer on FTO glass: wipe the surface of FTO glass with glass cleaning powder to remove particulate matter and oil stains, and sequentially ultrasonic clean the FTO glass in deionized water added with glass cleaner, deionized water, acetone and ethanol, each for 30 minutes. Dry the glass surface with nitrogen gun to ensure no water stains or particles are left. Place the dried FTO glass into an ultraviolet ozone cleaning machine for 20 minutes to improve the surface wettability. Drop 150 μL of Me-4PACz solution with a concentration of 0.5 mg / mL on the surface of the FTO glass, spin at a speed of 3000 rpm for 30 s, and then anneal at 100°C for 10 min to obtain the Me-4PACz layer.

[0088] S2. Preparing perovskite light absorption layer on Me-4PACz layer: dissolve CsCl (0.065 M), MAI (0.065 M), FAI (1.17 M), PbI2 (1.365 M) and MACl (0.26 M) in a mixed solvent of DMF and DMSO with a volume ratio of 4:1 to obtain a perovskite precursor solution; add CN-BSA to the perovskite precursor solution to obtain a perovskite solution, and the concentration of CN-BSA in the perovskite solution is 0.25 mg / mL; spin 80 μL of the perovskite solution on the hole transport layer at an acceleration of 200 rpm / s for 10 s to a speed of 2000 rpm for one-step spin coating, then accelerate at an acceleration of 2000 rpm / s for 2 s to a speed of 4000 rpm for two-step spin coating, drop 200 μL of CB at the 20th second after the start of two-step spin coating, continue to spin for 10 s, and then end the spin coating, and sequentially anneal at 70°C for 10 min, at 100°C for 60 min, and at 150°C for 10 min to obtain the perovskite light absorption layer.

[0089] S3. Preparing PEAI layer on perovskite light absorption layer: spin 3000 rpm of PEAI solution (concentration: 5 mg / mL, solvent: isopropanol) on the perovskite light absorption layer for 30 s, and then anneal at 90°C for 5 min to obtain the PEAI layer.

[0090] S4. Depositing 25 nm of C60 layer on PEAI layer by high vacuum evaporation method.

[0091] S5. Depositing 10 nm of SnO x layer on C60 layer by atomic deposition method.

[0092] S6. Depositing 10 nm of SnOx A 200 nm Ag electrode is deposited on the layer to obtain the CN-BSA-based perovskite solar cell.

[0093] Example 6

[0094] A CN-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x The layers and Ag electrode are substantially the same as in the preparation method of Example 1, except that in S2, the concentration of CN-BSA in the perovskite solution is 0.50 mg / mL.

[0095] Example 7

[0096] A CN-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x The layers and Ag electrode are substantially the same as in the preparation method of Example 1, except that in S2, the concentration of CN-BSA in the perovskite solution is 1.00 mg / mL.

[0097] Example 8

[0098] A CN-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x The layers and Ag electrode are substantially the same as in the preparation method of Example 1, except that in S2, the concentration of CN-BSA in the perovskite solution is 2.00 mg / mL.

[0099] Example 9

[0100] A COOH-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode.

[0101] The preparation method of the COOH-BSA-based perovskite solar cell of Example 9 includes the following steps:

[0102] S1. Preparation of Me-4PACz layer on FTO glass: The FTO glass surface was wiped with glass cleaning powder to remove particulate matter and oil. The FTO glass was then ultrasonically cleaned sequentially in deionized water, acetone, and ethanol with glass cleaning agent added, with each step lasting 30 minutes. The glass surface was dried using a nitrogen gun to ensure no water stains or particulate residue remained. The dried FTO glass was then treated in a UV ozone cleaner for 20 minutes to improve surface wettability. 150 μL of a 0.5 mg / mL Me-4PACz solution was dropped onto the FTO glass surface and spin-coated at 3000 rpm for 30 seconds. After annealing at 100°C for 10 minutes, the Me-4PACz layer was obtained.

[0103] S2. Preparation of a perovskite light-absorbing layer on the Me-4PACz layer: CsCl (0.065M), MAI (0.065M), FAI (1.17M), PbI2 (1.365M), and MACl (0.26M) were dissolved in a mixed solvent of DMF and DMSO, with a volume ratio of DMF to DMSO of 4:1, to obtain a perovskite precursor solution; COOH-BSA was added to the perovskite precursor solution to obtain a perovskite solution, wherein the concentration of COOH-BSA in the perovskite solution was 0.25 mg / mL; 80 μL of the perovskite solution was spin-coated onto the hole transport layer, and a first-step spin-coating was performed by accelerating at 200 rpm / s for 10 s to 2000 rpm, followed by a second-step spin-coating by accelerating at 2000 rpm / s for 2 s to 4000 rpm. 200 μL of the second-step spin-coating solution was added dropwise 20 s after the start of the second-step spin-coating. CB, continue spin coating for 10 seconds and then stop spin coating. Then anneal at 70℃ for 10 min, 100℃ for 60 min and 150℃ for 10 min in sequence to obtain perovskite light absorption layer.

[0104] S3. Preparation of PEAI layer on perovskite light-absorbing layer: PEAI solution (concentration of 5 mg / mL, solvent of isopropanol) was spin-coated on the perovskite light-absorbing layer at a speed of 3000 rpm for 30 s, and then annealed at 90°C for 5 min to obtain PEAI layer.

[0105] S4. A 25nm C60 layer is deposited on the PEAI layer by high vacuum evaporation.

[0106] S5. Deposit 10 nm of SnO on a C60 layer using atomic deposition. x layer;

[0107] S6. SnO by vapor deposition x A 200 nm Ag electrode was deposited on the layer to obtain the COOH-BSA-based perovskite solar cell.

[0108] Example 10

[0109] A COOH-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode, which are sequentially arranged on one side of the FTO glass, and a preparation method thereof, and the difference from the preparation method of Example 1 is that, in S2, the concentration of COOH-BSA in the perovskite solution is 0.50 mg / mL.

[0110] Example 11

[0111] A COOH-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode, which are sequentially arranged on one side of the FTO glass, and a preparation method thereof, and the difference from the preparation method of Example 1 is that, in S2, the concentration of COOH-BSA in the perovskite solution is 1.00 mg / mL.

[0112] Example 12

[0113] A COOH-BSA-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode, which are sequentially arranged on one side of the FTO glass, and a preparation method thereof, and the difference from the preparation method of Example 1 is that, in S2, the concentration of COOH-BSA in the perovskite solution is 2.00 mg / mL.

[0114] Comparative Example 1

[0115] A perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer and an Ag electrode, which are sequentially arranged on one side of the FTO glass.

[0116] A preparation method of the perovskite solar cell of Comparative Example 1 includes the following steps:

[0117] S1. Preparation of Me-4PACz layer on FTO glass: The FTO glass surface was wiped with glass cleaning powder to remove particulate matter and oil. The FTO glass was then ultrasonically cleaned sequentially in deionized water, acetone, and ethanol with glass cleaning agent added, with each step lasting 30 minutes. The glass surface was dried using a nitrogen gun to ensure no water stains or particulate residue remained. The dried FTO glass was then treated in a UV ozone cleaner for 20 minutes to improve surface wettability. 150 μL of a 0.5 mg / mL Me-4PACz solution was dropped onto the FTO glass surface and spin-coated at 3000 rpm for 30 seconds. After annealing at 100°C for 10 minutes, the Me-4PACz layer was obtained.

[0118] S2. Preparation of a perovskite light-absorbing layer on the Me-4PACz layer: CsCl (0.065M), MAI (0.065M), FAI (1.17M), PbI2 (1.365M), and MACl (0.26M) were dissolved in a mixed solvent of DMF and DMSO, with a volume ratio of DMF to DMSO of 4:1, to obtain a perovskite precursor solution; 80 μL of the perovskite precursor solution was spin-coated onto the hole transport layer, and then sprayed at 20°C. A first-step spin coating was performed by accelerating from 0 rpm / s for 10 s to 2000 rpm, followed by a second-step spin coating by accelerating from 2000 rpm / s for 2 s to 4000 rpm. 200 μL CCB was added 20 s after the start of the second-step spin coating, and spin coating was continued for another 10 s before ending the spin coating. The coating was then annealed sequentially at 70 °C for 10 min, at 100 °C for 60 min, and at 150 °C for 10 min to obtain the perovskite light-absorbing layer.

[0119] S3. Preparation of PEAI layer on perovskite light-absorbing layer: PEAI solution (concentration of 5 mg / mL, solvent of isopropanol) was spin-coated on the perovskite light-absorbing layer at a speed of 3000 rpm for 30 s, and then annealed at 90°C for 5 min to obtain PEAI layer.

[0120] S4. A 25nm C60 layer is deposited on the PEAI layer by high vacuum evaporation.

[0121] S5. Deposit 10 nm of SnO on a C60 layer using atomic deposition. x layer;

[0122] S6. SnO by vapor deposition x A 200 nm Ag electrode is deposited on the layer to obtain the perovskite solar cell.

[0123] Comparative Example 2

[0124] A 4-fluorobenzenesulfonamide-based perovskite solar cell includes FTO glass, a Me-4PACz layer, a perovskite light absorption layer, a PEAI layer, a C60 layer, a SnO x layer, and an Ag electrode arranged in sequence on one side of the FTO glass.

[0125] The preparation method of the 4-fluorobenzenesulfonamide-based perovskite solar cell of Comparative Example 2 includes the following steps:

[0126] S1. Preparing a Me-4PACz layer on FTO glass: wipe the surface of the FTO glass with a glass cleaning powder to remove particulate matter and oil stains, and sequentially ultrasonic clean the FTO glass in deionized water added with a glass cleaning agent, deionized water, acetone, and ethanol, with a cleaning time of 30 minutes for each step. Dry the glass surface with a nitrogen gun to ensure that there is no water stain or particle residue. Place the dried FTO glass in an ultraviolet ozone cleaning machine for 20 minutes to improve the surface wettability. Drop 150 μL of Me-4PACz solution with a concentration of 0.5 mg / mL on the surface of the FTO glass, spin at a speed of 3000 rpm for 30 s, and then anneal at 100°C for 10 min to obtain the Me-4PACz layer.

[0127] S2. Preparing a perovskite light absorption layer on the Me-4PACz layer: dissolve CsCl (0.065 M), MAI (0.065 M), FAI (1.17 M), PbI2 (1.365 M), and MACl (0.26 M) in a mixed solvent of DMF and DMSO with a volume ratio of 4:1 to obtain a perovskite precursor solution; add 4-fluorobenzenesulfonamide to the perovskite precursor solution to obtain a perovskite solution, and the concentration of 4-fluorobenzenesulfonamide in the perovskite solution is 0.50 mg / mL; spin 80 μL of the perovskite solution on the hole transport layer at an acceleration of 200 rpm / s for 10 s to a speed of 2000 rpm for one-step spinning, and then at an acceleration of 2000 rpm / s for 2 s to a speed of 4000 rpm for two-step spinning; drop 200 μL of CB at the 20th second after the start of two-step spinning, continue to spin for 10 s, and then stop spinning; sequentially anneal at 70°C for 10 min, at 100°C for 60 min, and at 150°C for 10 min to obtain the perovskite light absorption layer.

[0128] S3. Preparing a PEAI layer on the perovskite light absorption layer: spin the PEAI solution (concentration: 5 mg / mL, solvent: isopropanol) at a speed of 3000 rpm on the perovskite light absorption layer for 30 s, and then anneal at 90°C for 5 min to obtain the PEAI layer.

[0129] S4. A 25 nm layer of C60 is deposited on the PEAI layer by high vacuum evaporation.

[0130] S5. A 10 nm layer of SnO2 is deposited on the C60 layer using atomic deposition. x

[0131] S6. A 200 nm Ag electrode is deposited on the SnO2 layer by evaporation to obtain the 4-fluorobenzenesulfonamide-based perovskite solar cell. x

[0132] Test Example 1

[0133] The perovskite light-absorbing layers in Example 2, Example 6, Example 10 and Comparative Examples 1 and 2 are subjected to morphology characterization and testing.

[0134] Figure 1 The SEM images of the perovskite light-absorbing layers in Example 2, Example 6, Example 10 and Comparative Example 1 show the changes in the grain size of the perovskite light-absorbing layers before and after doping. The surface SEM images show that the grain size of the perovskite light-absorbing layers is significantly increased, the number of grain boundaries is reduced, and the quality of the perovskite light-absorbing layers is improved. The cross-sectional SEM images show that the vertical grain size of the perovskite light-absorbing layers is significantly increased, which is beneficial to the transport and extraction of carriers.

[0135] Figure 2 The AFM images of the perovskite light-absorbing layers in Example 2, Example 6, Example 10 and Comparative Example 1 are shown in FIG. 6. Figure 2 As can be seen from FIG. 6, the grain size and surface roughness of the perovskite light-absorbing layers change before and after doping. After modification by the dual-site passivation agent, the grain size of the perovskite light-absorbing layers is significantly increased, and the surface roughness is significantly reduced. The gradual reduction of the roughness (RMS) indicates that the surface smoothness is improved, which is beneficial to the close contact with the electron transport layer (ETL), thereby minimizing charge recombination and improving carrier extraction.

[0136] Figure 3 The XRD images of the perovskite light-absorbing layers in Example 2, Example 6, Example 10 and Comparative Example 1 are shown in FIG. 7. The peak intensity of the XRD shows that after adding the dual-site passivation agent, the diffraction peak intensity on the (100) and (200) crystal planes is significantly enhanced, and the PbI2 diffraction peak is significantly reduced, indicating that the crystalline quality of the perovskite light-absorbing layers is significantly enhanced, and the precipitation of PbI2 is inhibited.

[0137] The mechanism of the dual-site passivation agent on the perovskite surface is further explored based on the first-principle calculation of the density functional theory (DFT), and the simulation results are shown in FIG. 8. Figure 4 ​​CN-BSA was able to passivate the uncoordinated Pb2+ on the perovskite surface through a dual-site passivation mechanism 2+ The defect was coordinated to form a stable coordination structure with a binding energy (including Pb-N and Pb-O bonds) of -1.17684417 eV. In contrast, COOH-BSA also passivated the uncoordinated Pb2+ on the perovskite surface through a dual-site passivation mechanism 2+ The defect was coordinated, but its binding energy (two Pb-O bonds) was as high as -1.32823905 eV, exhibiting stronger surface anchoring ability. 4-Fluorobenzenesulfonamide, however, could only passivate the uncoordinated Pb2+ on the perovskite surface through a single-site passivation mechanism 2+ The defect was coordinated, but its binding energy (two Pb-O bonds) was as high as -1.32823905 eV, exhibiting stronger surface anchoring ability. 4-Fluorobenzenesulfonamide, however, could only passivate the uncoordinated Pb2+ on the perovskite surface through a single-site passivation mechanism

[0138] The effect of the dual-site passivation agent on the optical properties of the perovskite light absorption layer was evaluated by ultraviolet-visible absorption spectroscopy (UV-Vis), Figure 5 The UV-Vis absorption spectrum (left) and band gap spectrum (right) of the perovskite light absorption layer in Example 2, Example 6, Example 10, and Comparative Example 1 are shown. The UV-Vis absorption spectrum shows that the absorption edge and optical band gap (Eg) of the perovskite light absorption layer modified with CN-BSA and COOH-BSA remained unchanged.

[0139] Figure 6 The steady-state photoluminescence (PL) spectrum (left) and time-resolved photoluminescence (TRPL) spectrum (right) of the perovskite light absorption layer in Example 2, Example 6, Example 10, and Comparative Example 1 are shown. After doping with the dual-site passivation agent, the PL intensity was significantly enhanced, and the average decay lifetime (τ avg ) calculated in TRPL was significantly improved, where the τ avg of the perovskite light absorption layer in Comparative Example 1 was 103.53 ns, the τ avg of the perovskite light absorption layer based on OH-BSA in Example 2 was 189.44 ns, the τ avg of the perovskite light absorption layer based on CN-BSA in Example 6 was 282.53 ns, and the τ avg of the perovskite light absorption layer based on COOH-BSA in Example 10 was 412.19 ns. The above results show that the dual-site passivation agent achieved effective defect passivation and significantly suppressed non-radiative recombination in the perovskite light absorption layer.

[0140] Test Example 1

[0141] The perovskite solar cells of Examples 1-12 and Comparative Example 1 were tested for performance using a Keithley 2400 source meter instrument and a light source (AM1.5G) provided by Enli to obtain current density-voltage (J-V) curve tests of the perovskite solar cells.

[0142] The perovskite solar cells of Examples 1-4 and Comparative Example 1 were tested for J-V curve, photovoltaic conversion efficiency (PCE), open-circuit voltage (V OC ), short-circuit current density (J SC ), and fill factor (FF) test results are shown in Table 1 and Figure 7

[0143] Table 1

[0144]

[0145] Figure 7 J-V curves of the perovskite solar cells of Examples 1-4 and Comparative Example 1.

[0146] The perovskite solar cells of Examples 5-8 and Comparative Example 1 were tested for J-V curve, PCE, V OC , J SC , and FF test results are shown in Table 2 and Figure 8

[0147] Table 2

[0148]

[0149] Figure 8 J-V curves of the perovskite solar cells of Examples 5-8 and Comparative Example 1.

[0150] The perovskite solar cells of Examples 9-12 and Comparative Example 1 were tested for J-V curve, PCE, V OC , J SC , and FF test results are shown in Table 3 and Figure 9

[0151] Table 3

[0152]

[0153] Figure 9 J-V curves of the perovskite solar cells of Examples 9-12 and Comparative Example 1.

[0154] The perovskite solar cells of Example 2, Example 6, Example 10, and Comparative Example 1 were tested for forward and reverse scan performance, PCE, V OC ​​​, J SC , FF and hysteresis factor (HI) test results are shown in Table 4 and Figure 10

[0155] Table 4

[0156]

[0157]

[0158] Figure 10 The positive and negative scan curves of the perovskite solar cells of Example 2, Example 6, Example 10 and Comparative Example 1.

[0159] Figure 11 The space charge limited current (SCLC) curves of the perovskite solar cells of Example 2, Example 6, Example 10 and Comparative Example 1, from which the space charge limited voltage (V TFT ) can be calculated, the defect density in the thin film, the defect density of the perovskite solar cell of Comparative Example 1 is 3.56 x 10 15 cm -3 , the defect density of the perovskite solar cell of Example 2 based on OH-BSA is 2.83 x 10 15 cm -3 , the defect density of the perovskite solar cell of Example 6 based on CN-BSA is 2.58 x 10 15 cm -3 , the defect density of the perovskite solar cell of Example 10 based on COOH-BSA is 2.33 x 10 15 cm -3 , it can be seen that the lower the V TFT , the smaller the defect density of the perovskite solar cell.

[0160] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Those skilled in the art should understand that on the basis of the above description, other different forms of changes or variations can also be made. Here, it is not necessary and also impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the claims of the present application.​

Claims

1. A perovskite solar cell based on a two-site passivator, characterized by, The perovskite light absorption layer comprises a dual-site passivation agent selected from one or more of the following structural formulas: wherein R1, R2 are different, and each of R1 and R2 is independently selected from one of sulfonamide group, amide group, ester group, aldehyde group, hydroxyl group, carboxyl group and cyano group.

2. The double-site passivant-based perovskite solar cell of claim 1, wherein, The dual-site passivation agent is selected from one or more of 4-hydroxybenzenesulfonamide, 4-cyanobenzenesulfonamide, 4-carboxybenzenesulfonamide, 4-formamidobenzoic acid, 1,4-benzenedicarboxylic acid dimethyl ester, 4-(methoxycarbonyl)benzoic acid, 4-formaldehyde benzoic acid methyl ester, 4-nitrilebenzamide, 5-cyano-2-pyridine carboxamide, 6-carbomyl nicotinic acid methyl ester, 6-aminocarbonylpyridine-3-carboxylic acid, 6-aminosulfonyl nicotinic acid, 6-aminosulfonyl-nicotinic acid methyl ester, 5-formylpyridine-2-sulfonamide, 5-cyanopyridine-2-sulfonamide, 5-cyanopyridine-2-carboxylic acid, 5-cyano-pyridine-2-carboxylic acid methyl ester, diethyl pyrazine-2,5-dicarboxylate, 5-(methoxycarbonyl)pyrazine-2-carboxylic acid, dimethyl pyrazine-2,5-dicarboxylate, 5-(aminocarbonyl)-2-pyrazine carboxylic acid and 5-cyano-2-pyrazine sulfonamide.

3. The double-site passivant-based perovskite solar cell of claim 1, wherein, The dual-site passivation agent-based perovskite solar cell comprises an anode substrate, a hole transport layer, a perovskite light absorption layer, a perovskite passivation layer, an electron transport layer, a perovskite protective layer and a cathode electrode arranged in sequence on one side of the anode substrate.

4. The double-site passivant-based perovskite solar cell of claim 1, wherein, The material of the perovskite passivation layer includes phenethylamine hydroiodide; the material of the perovskite protective layer includes SnO x wherein 0 < x ≤ 2.

5. A method for producing the perovskite solar cell based on a two-site passivator according to any one of claims 1 to 3, characterized by, The method comprises the following steps: S1. Preparing a hole transport layer on an anode substrate; S2. Dissolving cesium chloride, methylammonium iodide, formamidinium iodide, lead iodide and methylammonium chloride in an organic solvent to react to obtain a perovskite precursor solution; A dual-site passivation agent is added to the perovskite precursor solution to obtain a perovskite solution, and the perovskite solution is coated on the hole transport layer prepared in S1 to obtain a perovskite light absorption layer; S3. Preparing a perovskite passivation layer on the perovskite light absorption layer prepared in S2; S4. Preparing an electron transport layer on the perovskite passivation layer prepared in S3; S5. Preparing a perovskite protective layer on the electron transport layer prepared in S4; S6. Preparing a cathode electrode on the perovskite protective layer prepared in S5 to obtain the dual-site passivation agent-based perovskite solar cell.

6. The production method according to claim 4, characterized by, In S1, the preparation of the hole transport layer comprises the following steps: spin coating a hole transport layer solution on the anode substrate at a rotation speed of 2500-3500 rpm for 25-35 s, and then annealing at 90-110℃ for 5-15 min to obtain the hole transport layer.

7. The preparation method according to claim 4, characterized in that, In S2, the concentration of the dual-site passivation agent in the perovskite solution is 0.1-4 mg / mL.

8. The preparation method according to claim 4, characterized in that, In S2, the perovskite solution is spin coated on the hole transport layer, and the perovskite light absorption layer is obtained after annealing.

9. The preparation method according to claim 7, characterized in that, The specific operation of the spin coating is: accelerating at an acceleration of 150-250 rpm / s for 6-16 s to a rotation speed of 1500-2500 rpm for one-step spin coating, then accelerating at an acceleration of 1500-2500 rpm / s for 1-3 s to a rotation speed of 3500-4500 rpm for two-step spin coating, adding the anti-solvent at the 15-25 s after the start of the two-step spin coating, and ending the spin coating after continuing the spin coating for 10-15 s.

10. The production method according to claim 7 or 8, characterized by, The specific operation of the annealing treatment is: sequentially performing annealing treatment at 60-80 ℃ for 5-15 min, at 90-110 ℃ for 50-70 min, and at 140-160 ℃ for 5-15 min.

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