Perovskite solar cell and preparation method thereof

Abstract

The invention provides a perovskite solar cell and a preparation method thereof. The perovskite solar cell comprises a transparent conductive substrate, a first charge transport layer, a first passivation layer, a perovskite light absorption layer, a second passivation layer, a second charge transport layer and a back electrode which are sequentially stacked. Materials of the first passivation layer and the second passivation layer respectively and independently comprise 4-chlorobenzene sulfonyl chloride and / or p-fluorobenzene sulfonyl chloride. According to the perovskite solar cell, the first passivation layer and the second passivation layer are arranged on the two sides of the perovskite layer respectively, and the perovskite solar cell with excellent performance is prepared by further designing materials of the first passivation layer and the second passivation layer.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a perovskite solar cell and its preparation method. Background Technology

[0002] The world's energy focus is gradually shifting from traditional energy sources to renewable energy. Solar energy is abundant in nature, relatively easy to obtain, and possesses clean and pollution-free characteristics, making it a reliable long-term energy source for stable global development. Among numerous clean energy sources, perovskite solar cells are an important component of renewable energy. These solar cells overcome the shortcomings of previous generations of solar cells due to their low manufacturing cost, simple synthesis process, high photoelectric conversion efficiency, large-area production capability, and environmental friendliness, attracting significant attention from researchers.

[0003] Despite extensive research efforts aimed at improving battery efficiency and stability, the ubiquitous crystal defect-mediated charge recombination remains one of the major limiting factors for further performance enhancement. These undesirable defects are unavoidable in solution synthesis, and have become more severe, particularly with advancements in perovskite fabrication. Among all defect types, surface defects, common in perovskites, are one of the primary factors hindering battery efficiency and stability.

[0004] Therefore, developing a simple, universal, and effective perovskite film surface passivation strategy to provide a high-performance perovskite solar cell is crucial for device optimization and eventual commercialization. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a perovskite solar cell and its fabrication method. The present invention achieves high-performance perovskite solar cells by respectively depositing a first passivation layer and a second passivation layer on both sides of a perovskite layer, and further by designing the materials of the first and second passivation layers.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a perovskite solar cell, the perovskite solar cell comprising a transparent conductive substrate, a first charge transport layer, a first passivation layer, a perovskite light-absorbing layer, a second passivation layer, a second charge transport layer, and a back electrode, which are stacked sequentially.

[0008] The materials of the first passivation layer and the second passivation layer each independently comprise 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride.

[0009] This invention provides a high-performance perovskite solar cell by setting a first passivation layer and a second passivation layer on both sides of a perovskite layer, and further by designing the materials of the first passivation layer and the second passivation layer.

[0010] Compared to linear chain ligands, the flattened benzene ring structure in 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride is expected to be parallel to the surface, thus more effectively passivating perovskite surface defects. To achieve strong binding to the perovskite surface, the -SO3- functional group can interact with Pb. 2+ Strong coordination allows ethanol in the passivation layer precursor solution to dissolve or dilute benzenesulfonyl salt groups, maintaining the integrity of the perovskite without causing any damage. Cl ions can regulate the perovskite crystallization process, and passivating defects is an effective method to improve the power conversion efficiency of perovskite solar cells, due to the stronger Pb-Cl bond compared to Pb-I and Pb-Br bonds. Fluorine atoms in p-fluorobenzenesulfonyl chloride (P-FC) tend to combine with positively charged FA ions in the perovskite through hydrogen bonds, further improving the overall performance of the perovskite solar cell. Therefore, this invention, through the design of the materials for the first and second passivation layers, has prepared a perovskite solar cell with excellent performance.

[0011] This invention uses 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride for dual passivation of the upper and lower interfaces of the perovskite light-absorbing layer, directly serving as pre- and post-treatment agents for the perovskite light-absorbing layer. The first passivation layer at the lower interface of the perovskite improves the crystallinity of the perovskite light-absorbing layer, while the second passivation layer on the upper surface maintains the integrity of the perovskite light-absorbing layer without causing any damage. The multiple intermolecular interactions formed between 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride and the perovskite play a crucial role in determining the defect passivation effect. Therefore, the perovskite light-absorbing layer film modified with 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride exhibits a more uniform surface potential distribution, significantly reduced defect density, and improved charge transfer, resulting in a substantial increase in the power conversion efficiency of the perovskite solar cell and good cell stability.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0013] As a preferred embodiment of the present invention, the materials of the first passivation layer and the second passivation layer each independently comprise a combination of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride.

[0014] Preferably, the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:(0.25-6), for example, it can be 1:0.25, 1:0.3, 1:0.4, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:3.3, 1:3.6, 1:3.8, 1:4, 1:4.5, 1:5, 1:5.5 or 1:6, etc., and more preferably 1:(0.5-4).

[0015] In this invention, by designing a combination of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride as the materials for the first and second passivation layers, and further controlling the mass ratio of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride within a specific range, the overall performance of perovskite solar cells is further improved.

[0016] As a preferred technical solution of the present invention, the thickness of the first passivation layer and the second passivation layer are each independently ≤2nm, for example, they can be 1nm, 1.2nm, 1.4nm, 1.6nm, 1.8nm or 2nm, etc. Obviously, the thickness of the passivation layer is not less than the thickness of a single molecule of the passivation layer material.

[0017] This invention achieves high-performance perovskite solar cells by controlling the thicknesses of the first and second passivation layers within a specific range. If the thicknesses of the first and second passivation layers are too small, their passivation effect on the perovskite light-absorbing layer is poor, resulting in poor performance of the prepared perovskite solar cell. Conversely, if the thicknesses of the first and second passivation layers are too large, a barrier layer is formed, hindering charge transport and also leading to poor performance of the prepared perovskite solar cell.

[0018] As a preferred embodiment of the present invention, the transparent conductive substrate comprises FTO conductive glass.

[0019] As a preferred embodiment of the present invention, the first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer;

[0020] Alternatively, the first charge transport layer may be an electron transport layer, and the second charge transport layer may be a hole transport layer.

[0021] Preferably, the material of the hole transport layer includes any one of nickel oxide, aluminum oxide, styrene sulfonate, polytriarylamine, and cuprous thiocyanate.

[0022] Preferably, the thickness of the first charge transport layer is 5 to 15 nm, for example, it can be 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, 11 nm, 12 nm, 13 nm, 14 nm or 15 nm.

[0023] Preferably, the electron transport layer is made of at least one of fullerene, tin oxide (SnO2) layer, or bicyclo[1.1.1]pentane. For example, if the electron transport layer comprises a fullerene layer (C... 60 The electron transport layer has a thickness of 15-20 nm (e.g., 15 nm, 16 nm, 17 nm, 18 nm, 19 nm or 20 nm), and the electron transport layer also includes a tin oxide (SnO2) layer or a bicyclic [1.1.1]pentane (BCP) layer with a thickness of 0-5 nm (e.g., 1 nm, 2 nm, 3 nm, 4 nm or 5 nm).

[0024] Preferably, the thickness of the electron transport layer is 15-25 nm, for example, it can be 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm or 25 nm.

[0025] As a preferred embodiment of the present invention, the chemical structure of the perovskite light-absorbing layer material is ABX3. The present invention does not impose any special restrictions on the specific selection of A, B, and X; commonly used perovskite light-absorbing layer materials in the art are applicable, including but not limited to: A being an organic amine cation and / or an inorganic alkali metal ion, and B being a divalent metal cation (such as Pb). 2+ and Sn 2+ ), where X is a halide anion.

[0026] Preferably, the thickness of the perovskite light-absorbing layer is 450–600 nm, for example, it can be 450 nm, 460 nm, 480 nm, 500 nm, 520 nm, 540 nm, 560 nm, 580 nm or 600 nm.

[0027] This invention also does not impose any special restrictions on the material of the back electrode. Commonly used materials in the field are applicable, including but not limited to: metal electrodes such as copper, silver, and gold, or transparent conductive oxides (TCO), conductive polymers such as PEDOT:PSS, or non-metallic electrodes such as carbon.

[0028] Preferably, the thickness of the back electrode is 100-120 nm, for example, it can be 100 nm, 102 nm, 104 nm, 106 nm, 108 nm, 110 nm, 112 nm, 114 nm, 116 nm, 118 nm or 120 nm.

[0029] In a second aspect, the present invention provides a method for fabricating a perovskite solar cell as described in the first aspect, the method comprising the following steps:

[0030] A first charge transport layer, a first passivation layer, a perovskite light-absorbing layer, a second passivation layer, a second charge transport layer, and a back electrode are sequentially disposed on one side of a conductive substrate to obtain the perovskite solar cell.

[0031] As a preferred embodiment of the present invention, the method for setting the first passivation layer includes the following steps:

[0032] A first passivation layer precursor solution is coated on one side of the first charge transport layer and then annealed to obtain the first passivation layer.

[0033] The first passivation layer precursor solution is obtained by mixing the material of the first passivation layer with a polar organic solvent;

[0034] The concentration of the material of the first passivation layer in the first passivation layer precursor solution is 0.05 to 0.5 mg / mL (for example, it can be 0.05 mg / mL, 0.08 mg / mL, 0.1 mg / mL, 0.15 mg / mL, 0.2 mg / mL, 0.25 mg / mL, 0.3 mg / mL, 0.4 mg / mL or 0.5 mg / mL, etc.), and more preferably 0.05 to 0.25 mg / mL.

[0035] Preferably, the solvent of the first passivation layer precursor solution is ethanol.

[0036] Preferably, the annealing temperature is 90-110°C, for example, it can be 90°C, 92°C, 94°C, 96°C, 98°C, 100°C, 102°C, 104°C, 106°C, 108°C or 110°C.

[0037] Preferably, the annealing time is 4 to 6 minutes, for example, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes or 6 minutes.

[0038] As a preferred embodiment of the present invention, the method for setting the perovskite light-absorbing layer includes the following steps:

[0039] A perovskite precursor solution is coated on one side of the first passivation layer and then annealed to obtain the perovskite light-absorbing layer.

[0040] Preferably, the annealing temperature is 100-130°C, for example, it can be 100°C, 102°C, 105°C, 108°C, 110°C, 112°C, 115°C, 118°C, 120°C, 123°C, 126°C, 127°C or 130°C.

[0041] Preferably, the annealing time is 30 to 60 minutes, for example, it can be 30 minutes, 33 minutes, 36 minutes, 38 minutes, 40 minutes, 42 minutes, 44 minutes, 46 minutes, 48 ​​minutes, 50 minutes, 52 minutes, 54 minutes, 56 minutes, 58 minutes, or 60 minutes.

[0042] As a preferred embodiment of the present invention, the method for setting the second passivation layer includes the following steps:

[0043] A second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer and annealed to obtain the second passivation layer.

[0044] The second passivation layer precursor solution is obtained by mixing the material of the second passivation layer with a polar organic solvent;

[0045] The concentration of the material of the second passivation layer in the second passivation layer precursor solution is 0.05 to 0.5 mg / mL (for example, it can be 0.05 mg / mL, 0.08 mg / mL, 0.1 mg / mL, 0.15 mg / mL, 0.2 mg / mL, 0.25 mg / mL, 0.3 mg / mL, 0.4 mg / mL or 0.5 mg / mL, and more preferably 0.05 to 0.25 mg / mL).

[0046] Preferably, the solvent of the second passivation layer precursor solution is ethanol.

[0047] Preferably, the annealing temperature is 90-110°C, for example, it can be 90°C, 92°C, 94°C, 96°C, 98°C, 100°C, 102°C, 104°C, 106°C, 108°C or 110°C.

[0048] Preferably, the annealing time is 4 to 6 minutes, for example, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes or 6 minutes.

[0049] As a preferred embodiment of the present invention, the method for preparing the perovskite solar cell specifically includes the following steps:

[0050] A first charge transport layer is sequentially disposed on one side of a transparent conductive substrate;

[0051] A first passivation layer precursor solution is coated on one side of the first charge transport layer and annealed at 90–110°C for 4–6 min to obtain the first passivation layer.

[0052] A perovskite precursor solution is coated on one side of the first passivation layer and annealed at 100-130℃ for 30-60 min to obtain a perovskite light-absorbing layer.

[0053] A second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer and annealed at 90–110 °C for 4–6 min to obtain the second passivation layer.

[0054] A second charge transport layer and a back electrode are sequentially disposed on one side of the second passivation layer to obtain the perovskite solar cell.

[0055] It should be noted that the present invention does not impose any special restrictions on the preparation methods of the first charge transport layer, the second charge transport layer and the back electrode, and commonly used process methods and process conditions in the art are applicable.

[0056] It should also be noted that the coating method in the perovskite solar cell provided by the present invention includes at least one of spin coating, vapor deposition, slit coating, scraping coating, or screen printing.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] (1) The present invention prepares a perovskite solar cell with excellent performance by setting a first passivation layer and a second passivation layer on both sides of the perovskite layer, and selecting materials including 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride as the materials of the first passivation layer and the second passivation layer.

[0059] (2) The present invention further improves the overall performance of perovskite solar cells by further selecting a combination of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride as the materials of the first passivation layer and the second passivation layer, and controlling the mass ratio of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride within a specific range, and controlling the thickness of the passivation layer within a specific range, that is, controlling the concentration range of 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride in the passivation layer precursor solution within a specific range. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the structure of the perovskite solar cell provided in Embodiment 1 of the present invention;

[0061] Figure 2 This is a comparison chart of the normalized efficiency of the perovskite solar cells provided in Example 1 and Comparative Example 1 of the present invention at a relative humidity of 30% RH in air.

[0062] Among them, 1-transparent conductive substrate, 2-hole transport layer, 3-first passivation layer, 4-perovskite light-absorbing layer, 5-second passivation layer, 6-electron transport layer, and 7-back electrode. Detailed Implementation

[0063] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be considered as specific limitations thereof.

[0064] Example 1

[0065] This embodiment provides a perovskite solar cell and its fabrication method. A schematic diagram of the perovskite solar cell is shown below. Figure 1 As shown, it includes a transparent conductive substrate 1, a hole transport layer 2, a first passivation layer 3, a perovskite light-absorbing layer 4, a second passivation layer 5, an electron transport layer 6, and a back electrode 7, which are stacked in sequence.

[0066] The conductive substrate is FTO conductive glass with a thickness of 2.2 mm;

[0067] The hole transport layer is made of nickel oxide and has a thickness of 10 nm.

[0068] The first passivation layer 3 is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride of 1:1 and a thickness of approximately 1 nm.

[0069] The perovskite light-absorbing layer 4 is made of FA. 0.85 Cs 0.15 PbI3, with a thickness of 500 nm;

[0070] The second passivation layer 5 is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride of 1:1 and a thickness of approximately 1 nm.

[0071] The material of the electron transport layer 6 includes C. 60 SnO2, with a thickness of 20nm;

[0072] The back electrode 7 is made of Cu and has a thickness of 110 nm.

[0073] The fabrication method of the above perovskite solar cells is as follows:

[0074] (1) In FTO conductive glass (2.5×2.5cm) 2 A hole transport layer is obtained by vacuum evaporation of nickel oxide on one side.

[0075] (2) Mix 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride with ethanol to obtain a first passivation layer precursor solution. Coat the first passivation layer precursor solution on one side of the hole transport layer and anneal at 100°C for 5 min to obtain the first passivation layer. The concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.1 mg / mL and the concentration of p-fluorobenzenesulfonyl chloride is 0.1 mg / mL.

[0076] (3) Preparation of perovskite precursor solution: 29.74 mg MACl, 216.68 mg FAI and 640.76 mg PbI2 were dissolved in DMF and DMSO (the volume ratio of DMF to DMSO was 8:1) to form perovskite precursor solution;

[0077] A perovskite precursor solution was coated on one side of the first passivation layer and annealed at 120°C for 30 min to obtain a perovskite light-absorbing layer.

[0078] (4) Mix 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride with ethanol to obtain a second passivation layer precursor solution. Coat the second passivation layer precursor solution on one side of the perovskite light-absorbing layer and anneal at 100°C for 5 min to obtain the second passivation layer. The concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.1 mg / mL and the concentration of p-fluorobenzenesulfonyl chloride is 0.1 mg / mL.

[0079] (5) A C layer with a thickness of 15 nm is deposited on one side of the second passivation layer. 60 Then, a SnO2 layer with a thickness of 5 nm is deposited by vapor deposition to obtain the electron transport layer;

[0080] (6) Metal Cu is deposited on one side of the electron transport layer to obtain a back electrode with a thickness of 100 nm, thus completing the fabrication of the perovskite solar cell.

[0081] Example 2

[0082] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is p-fluorobenzenesulfonyl chloride.

[0083] In step (2): p-fluorobenzenesulfonyl chloride and ethanol are mixed to obtain a first passivation layer precursor solution. The first passivation layer precursor solution is scraped onto one side of the hole transport layer. The concentration of p-fluorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.1 mg / mL.

[0084] Other conditions are the same as in Example 1.

[0085] Example 3

[0086] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the second passivation layer is p-fluorobenzenesulfonyl chloride.

[0087] In step (4): p-fluorobenzenesulfonyl chloride and ethanol are mixed to obtain a second passivation layer precursor solution. The second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer. The concentration of p-fluorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.1 mg / mL.

[0088] Other conditions are the same as in Example 1.

[0089] Example 4

[0090] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the materials of the first passivation layer and the second passivation layer are both p-fluorobenzenesulfonyl chloride.

[0091] In step (2): p-fluorobenzenesulfonyl chloride and ethanol are mixed to obtain a first passivation layer precursor solution. The first passivation layer precursor solution is scraped onto one side of the hole transport layer. The concentration of p-fluorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.1 mg / mL.

[0092] In step (4): p-fluorobenzenesulfonyl chloride and ethanol are mixed to obtain a second passivation layer precursor solution. The second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer. The concentration of p-fluorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.1 mg / mL.

[0093] Other conditions are the same as in Example 1.

[0094] Example 5

[0095] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the materials of the first passivation layer and the second passivation layer are both 4-chlorobenzenesulfonyl chloride.

[0096] In step (2): 4-chlorobenzenesulfonyl chloride and ethanol are mixed to obtain a first passivation layer precursor solution. The first passivation layer precursor solution is scraped onto one side of the hole transport layer. The concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.1 mg / mL.

[0097] In step (4): 4-chlorobenzenesulfonyl chloride and ethanol are mixed to obtain a second passivation layer precursor solution. The second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer. The concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.1 mg / mL.

[0098] Other conditions are the same as in Example 1.

[0099] Example 6

[0100] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, and the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:0.25.

[0101] The second passivation layer is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 1:0.25.

[0102] In step (2), the concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.16 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.04 mg / mL;

[0103] In step (4), the concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.16 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.04 mg / mL;

[0104] Other conditions are the same as in Example 1.

[0105] Example 7

[0106] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, and the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:0.54.

[0107] The second passivation layer is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 1:0.54.

[0108] In step (2), the concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.13 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.07 mg / mL;

[0109] In step (4), the concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.13 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.07 mg / mL;

[0110] Other conditions are the same as in Example 1.

[0111] Example 8

[0112] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, and the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:1.5.

[0113] The second passivation layer is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 1:1.5.

[0114] In step (2), the concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.08 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.12 mg / mL;

[0115] In step (4), the concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.08 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.12 mg / mL;

[0116] Other conditions are the same as in Example 1.

[0117] Example 9

[0118] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, and the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:4.

[0119] The second passivation layer is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 1:4.

[0120] In step (2), the concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.04 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.16 mg / mL;

[0121] In step (4), the concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.04 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.16 mg / mL;

[0122] Other conditions are the same as in Example 1.

[0123] Example 10

[0124] This embodiment provides a perovskite solar cell and its preparation method. The only difference from Embodiment 1 is that the material of the first passivation layer is 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, and the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride is 1:5.7.

[0125] The second passivation layer is made of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride, with a mass ratio of 1:5.7.

[0126] In step (2), the concentration of 4-chlorobenzenesulfonyl chloride in the first passivation layer precursor solution is 0.03 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.17 mg / mL;

[0127] In step (4), the concentration of 4-chlorobenzenesulfonyl chloride in the second passivation layer precursor solution is 0.03 mg / mL, and the concentration of p-fluorobenzenesulfonyl chloride is 0.17 mg / mL;

[0128] Other conditions are the same as in Example 1.

[0129] Example 11, Example 12

[0130] Examples 11 and 12 respectively provide a perovskite solar cell and its preparation method. The only difference from Example 4 is that the thickness of the first passivation layer and the second passivation layer are different, the concentration of p-fluorobenzenesulfonyl chloride in the precursor solution of the first passivation layer in step (2) is different, and the concentration of p-fluorobenzenesulfonyl chloride in the precursor solution of the second passivation layer in step (4) is different. See Table 1 below for details.

[0131] Other conditions are the same as in Example 1.

[0132] Table 1

[0133]

[0134] Comparative Example 1

[0135] This comparative example provides a perovskite solar cell and its fabrication method. The only difference from Example 1 is that the perovskite solar cell does not have a first passivation layer and a second passivation layer.

[0136] In the method for preparing the perovskite solar cell, steps (2) and (4) are not performed;

[0137] Other conditions are the same as in Example 1.

[0138] Comparative Example 2

[0139] This comparative example provides a perovskite solar cell and its fabrication method. The only difference from Example 1 is that the perovskite solar cell does not have a first passivation layer.

[0140] In the method for preparing the perovskite solar cell, step (2) is not performed;

[0141] Other conditions are the same as in Example 1.

[0142] Comparative Example 3

[0143] This comparative example provides a perovskite solar cell and its fabrication method. The only difference from Example 1 is that the perovskite solar cell does not have a second passivation layer.

[0144] In the method for preparing the perovskite solar cell, step (4) is not performed;

[0145] Other conditions are the same as in Example 1.

[0146] The perovskite solar cells provided in the above embodiments and comparative examples were subjected to current-voltage tests under standard sunlight. Photovoltaic conversion efficiency (PCE) testing: Photovoltaic conversion efficiency is a direct parameter used to determine the photoelectric performance of perovskite solar cells. The photovoltaic parameters of perovskite solar cells include open-circuit voltage (Voc), short-circuit current (Jsc), fill factor (FF), and photovoltaic conversion efficiency (PCE). The main testing instruments included a solar simulator and a digital source meter. The solar simulator was used to test a light intensity of 100 mW / cm². 2 The test results are shown in Table 2:

[0147] Table 2

[0148]

[0149] The comparison of the normalized efficiency of the perovskite solar cells provided in Example 1 and Comparative Example 1 at 30% RH relative humidity is shown in the figure below. Figure 2 As shown. By Figure 2 As can be seen, the perovskite solar cell with dual passivation (i.e., setting a first passivation layer and a second passivation layer) at the upper and lower interfaces of the perovskite light-absorbing layer provided in Embodiment 1 of the present invention achieves a significant improvement in efficiency compared to the perovskite solar cell without an interface passivation layer (Comparative Example 1). Furthermore, the cell shows almost no efficiency degradation after 2000 hours of storage in air at a relative humidity of 30% RH, while the cell without a passivation layer has already degraded by 30% in less than 1300 hours. Therefore, the present invention, by setting a first passivation layer and a second passivation layer on both sides of the perovskite layer, achieves a breakthrough in the stability of perovskite solar cells, laying the foundation for commercial production.

[0150] As can be seen from the above, by setting a first passivation layer and a second passivation layer on both sides of the perovskite layer respectively, and selecting materials including 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride as the materials of the first passivation layer and the second passivation layer, the present invention has prepared a perovskite solar cell with excellent performance and a photoelectric conversion efficiency of 21.08 to 24.47%.

[0151] As can be seen from Examples 1-12, by controlling the thickness of the passivation layer within a specific range, the present invention further improves the overall performance of perovskite solar cells, with a photoelectric conversion efficiency of 22.53-24.47%.

[0152] As can be seen from Examples 1-12, the present invention further improves the overall performance of perovskite solar cells by using a combination of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride as the materials for the first and second passivation layers, controlling the mass ratio of 4-chlorobenzenesulfonyl chloride to p-fluorobenzenesulfonyl chloride within the range of 1:(0.5-4), and controlling the thickness of the passivation layer within a specific range, i.e., controlling the concentration range of 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride in the passivation layer precursor solution within a specific range, thereby improving the photoelectric conversion efficiency of 22.58-24.47%.

[0153] In summary, this invention has achieved a high-performance perovskite solar cell by setting a first passivation layer and a second passivation layer on both sides of the perovskite layer, and by selecting materials including 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride as the first and second passivation layers.

[0154] The applicant declares that the detailed process flow of this invention is illustrated by the above embodiments, but this invention is not limited to the above detailed process flow, that is, it does not mean that this invention must rely on the above detailed process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of this invention.

Claims

1. A perovskite solar cell, characterized by, The perovskite solar cell comprises a transparent conductive substrate, a first charge transport layer, a first passivation layer, a perovskite light-absorbing layer, a second passivation layer, a second charge transport layer and a back electrode which are sequentially stacked. The material of the first passivation layer and the second passivation layer each independently comprises 4-chlorobenzenesulfonyl chloride and / or p-fluorobenzenesulfonyl chloride.

2. The perovskite solar cell according to claim 1, characterized in that, The material of the first passivation layer and the second passivation layer each independently comprises a combination of 4-chlorobenzenesulfonyl chloride and p-fluorobenzenesulfonyl chloride. Preferably, the mass ratio of the 4-chlorobenzenesulfonyl chloride and the p-fluorobenzenesulfonyl chloride is 1:(0.25-6), further preferably 1:(0.5-4). 3.The perovskite solar cell according to claim 1 or 2, characterized in that, The thickness of the first passivation layer and the second passivation layer each independently is ≤2nm.

4. The perovskite solar cell according to any one of claims 1 to 3, characterized in that, The first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer. Or, the first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer. Preferably, the material of the hole transport layer comprises any one of nickel oxide, aluminum trioxide, styrene sulfonate, polytriazole, cuprous thiocyanate. Preferably, the material of the electron transport layer comprises at least one of fullerene, a tin oxide (SnO2) layer or bicyclo[1.1.1]pentane.

5. A method of producing a perovskite solar cell as claimed in any one of claims 1 to 4, characterized by, The preparation method comprises the following steps: A first charge transport layer, a first passivation layer, a perovskite light-absorbing layer, a second passivation layer, a second charge transport layer and a back electrode are sequentially arranged on one side of a conductive substrate to obtain the perovskite solar cell.

6. The production method according to claim 5, wherein The method for arranging the first passivation layer comprises the following steps: A first passivation layer precursor solution is coated on one side of the first charge transport layer, and annealing is performed to obtain the first passivation layer. The concentration of the material of the first passivation layer in the first passivation layer precursor solution is 0.05-0.5mg / mL, further preferably 0.05-0.25mg / mL.

7. The production method according to claim 6, wherein The solvent of the first passivation layer precursor solution is ethanol. Preferably, the temperature of the annealing is 90-110℃, and the time of the annealing is 4-6min.

8. The preparation method according to claim 5, characterized in that, The method for arranging the second passivation layer comprises the following steps: A second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer, and annealing is performed to obtain the second passivation layer. The concentration of the material of the second passivation layer in the second passivation layer precursor solution is 0.05-0.5mg / mL, further preferably 0.05-0.25mg / mL.

9. The production method according to claim 8, characterized by, The solvent of the second passivation layer precursor solution is ethanol. Preferably, the temperature of the annealing is 90-110℃, and the time of the annealing is 4-6min.

10. The production method according to any one of claims 6 to 9, characterized in that, The preparation method of the perovskite solar cell specifically comprises the following steps: A first charge transport layer is arranged on one side of a transparent conductive substrate; A first passivation layer precursor solution is coated on one side of the first charge transport layer, and annealing is performed at 90-110℃ for 4-6min to obtain the first passivation layer; A perovskite light-absorbing layer is arranged on one side of the first passivation layer; A second passivation layer precursor solution is coated on one side of the perovskite light-absorbing layer, and annealing is performed at 90-110℃ for 4-6min to obtain the second passivation layer; A second charge transport layer and a back electrode are sequentially arranged on one side of the second passivation layer to obtain the perovskite solar cell.

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