3, 4-difluorobenzene sulfonyl chloride modified perovskite solar cell

Abstract

The invention provides a perovskite solar cell modified by 3, 4-difluorobenzene sulfonyl chloride and a preparation method of the perovskite solar cell. The perovskite solar cell is prepared through a two-step spin-coating method, and 3, 4-difluorobenzene sulfonyl chloride is used as an interface modification material and is spin-coated on the interface of the perovskite layer and the hole transport layer by adopting the spin-coating method. Lewis bases S = O and F-in 3, 4-difluorobenzene sulfonyl chloride interact with the perovskite, so that the defect density of the perovskite is effectively reduced, the short-circuit current density is increased by about 3mA. Cm <-2 >, and the photoelectric energy conversion efficiency of the cell is increased by about 3.0%. The invention also provides a preparation method of the interface modified perovskite solar cell, and important reference is provided for realizing industrialization of the solar cell.

Description

Technical Field

[0001] The invention relates to a 3,4-difluorobenzenesulfonyl chloride modified perovskite solar cell, and belongs to the field of energy technology. Background Art

[0002] After years of development, solar cells have evolved into numerous types, including silicon solar cells, multi-element thin-film solar cells, dye-sensitized solar cells, and perovskite solar cells. Perovskite solar cells (PSCs), a new generation of solar cells, have achieved certified efficiencies of 26.95% in just a decade of development, exceeding the efficiency limit of silicon solar cells. These cells also offer advantages such as low manufacturing cost, simple processing, and high efficiency, making them a hot topic in solar cell research.

[0003] Planar PSCs typically consist of FTO / ITO conductive glass, an ETL (TiO2, ZnO, or SnO2), a perovskite layer, a HTL (Spiro-OMeTAD), and metal electrodes (Au or Ag). The perovskite layer, serving as the light-absorbing layer, has a significant impact on the conversion efficiency of PSCs. Energy level matching and defects at the film interfaces (between the ETL and perovskite layer, and between the perovskite layer and the HTL) are also important factors affecting the conversion efficiency of PSCs. Due to the inherent nature of the perovskite material, it is prone to producing different phase structures and numerous vacancy defects. These defects are easily decomposed by external elements such as water, oxygen, and high temperatures, affecting the efficiency and stability of PSCs. F atoms and sulfonyl groups, with their strong electronegativity, have been shown to effectively passivate vacancies and crystal defects in perovskites and are often used as dopants or interface modification materials to enhance the performance of PSCs.

[0004] Spin-coating 3,4-difluorobenzenesulfonyl chloride (F2BSCl) as an interface modification material between the perovskite layer and the hole transport layer can passivate perovskite surface defects, reduce interlayer carrier recombination rates, and improve device efficiency. This has certain reference significance in the field of solar cells, which focuses on conversion efficiency. Summary of the Invention

[0005] The present invention aims to prepare a perovskite solar cell with high conversion efficiency by introducing a 3,4-difluorobenzenesulfonyl chloride modified layer. 3,4-difluorobenzenesulfonyl chloride can optimize perovskite crystallization, thereby enhancing cell stability, accelerating carrier transport, and improving the cell's photoelectric conversion efficiency.

[0006] Another object of the present invention is to provide a method for preparing perovskite solar cells using a two-step spin coating method. This method has low production cost, high production efficiency, is green and environmentally friendly, and has simple equipment, which is more conducive to actual production and provides an important reference for the preparation of perovskite solar cells.

[0007] In order to achieve the above objectives, the present invention provides the following technical solutions:

[0008] A method for preparing a perovskite solar cell modified with 3,4-difluorobenzenesulfonyl chloride comprises the following steps:

[0009] Step 1: Clean the FTO conductive glass;

[0010] Step 2: preparing an electron transport layer on FTO conductive glass;

[0011] Step 3: preparing a perovskite layer on the electron transport layer;

[0012] Step 4: Preparation of 3,4-difluorobenzenesulfonyl chloride interface-modified perovskite solar cells;

[0013] Step 5: Weigh 6.2-6.4 μL of 3,4-difluorobenzenesulfonyl chloride solute and 1 mL of isopropanol to prepare a 3,4-difluorobenzenesulfonyl chloride solution, stir and mix thoroughly, and store at low temperature.

[0014] Step 6: Spin-coating the 3,4-difluorobenzenesulfonyl chloride solution on the perovskite layer and then annealing;

[0015] Preferably, the spin coating speed of the 3,4-difluorobenzenesulfonyl chloride solution is 3000-5000 rpm, the spin coating time is 20-40 s, and the acceleration is 2000-4000.

[0016] Preferably, the annealing temperature of the 3,4-difluorobenzenesulfonyl chloride modified layer is 90-110° C., and the annealing time is 5-15 min.

[0017] Step 7: Prepare a hole transport layer on the step 6, and prepare Ag and Au electrodes by a magnetron sputtering system to prepare a 3,4-difluorobenzenesulfonyl chloride modified perovskite solar cell.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a fluorinated sulfonyl interface modification and preparation method for perovskite solar cells, wherein the Lewis base S=O and the uncoordinated Pb 2+ Coordination-passivating cation defect, F - By working with FA + Form hydrogen bonds to inhibit ion migration in perovskite, Cl - You can also fill I -Vacancies can achieve passivation, which is beneficial to improving the photoelectric conversion efficiency of the battery.

[0020] This method, for the first time, spin-coats a 3,4-difluorobenzenesulfonyl chloride solution onto a perovskite layer, allowing the fluorinated sulfonyl groups to passivate the perovskite surface defects at the upper interface, resulting in a higher-quality thin film material. This method also offers low production cost and simple operation, providing an important reference for the research of perovskite solar cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Attachment Figure 1 : JV curves of the control group and perovskite solar cells containing perovskite layers modified with different concentrations of 3,4-difluorobenzenesulfonyl chloride; Attachment Figure 2 : Long-term stability test curves of perovskite solar cells of the control group and the perovskite layer modified with 3 mg / mL 3,4-difluorobenzenesulfonyl chloride;

[0022] Attachment Figure 3 : XRD patterns of perovskite films of control group and 3 mg / mL 3,4-difluorobenzenesulfonyl chloride modified perovskite layer. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and examples.

[0024] 1. Preparation of perovskite solar cells

[0025] 1: Cleaning of FTO conductive glass

[0026] Wipe the surface of the FTO conductive glass with detergent, and ultrasonically clean it with anhydrous ethanol, isopropyl alcohol, UP water, and anhydrous ethanol for 15 minutes in sequence. Put the cleaned FTO conductive glass into an oven for drying.

[0027] 2: Preparation of precursor solution

[0028] 1 mL of SnO2 aqueous solution and 5 mL of UP water were measured in a volume ratio of 1:5, and stirred at room temperature for uniform mixing; 600 mg of PbI2 powder, 9 mg of PbCl2 powder, 16.9 mg of CsI powder, 0.9 mL of DMF, and 0.1 mL of DMSO were weighed according to the molar concentration of perovskite of 1.3 M, and the mixture was heated and stirred in a glove box for 6 to 8 hours, hereinafter referred to as precursor solution 1; 60 mg of FAI powder, 6 mg of MACl powder, 6 mg of MABr powder, and 1 mL of IPA were weighed, and the mixture was stirred in a glove box for 6 to 8 hours, hereinafter referred to as precursor solution 2; 3,4-difluorobenzenesulfonyl chloride solution was prepared at a concentration of 10 mg / mL; 72.3 mg of Spiro-OMeTAD powder, 1 mL of chlorobenzene, 28.8 μL of TBP, and 17.5 μL of The acetonitrile solution of Li-TFSI was mixed and stirred in a glove box for 2 to 4 hours, hereinafter referred to as the Spiro solution. The acetonitrile solution of Li-TFSI was weighed at a ratio of 520 mg:1 mL, and the Li-TFSI powder and acetonitrile solution were mixed evenly in the glove box.

[0029] 3: Preparation of perovskite thin films

[0030] Turn on the hot plate and set it to 150℃ for preheating. Clean the dried FTO conductive glass with UV-ozone for 15 minutes. Use a syringe to extract an appropriate amount of SnO2 aqueous solution and filter it with an inorganic filter head to obtain a SnO2 aqueous solution without particulate impurities. Turn on the glue machine and set the spin coating parameters: speed 3000rpm, acceleration 2000, and spin coating time 30s. After the hot plate temperature rises to 150℃ and the FTO conductive glass is cleaned, use tweezers to move the FTO conductive glass to the turntable of the glue machine, turn on the vacuum pump to adsorb the FTO conductive glass, use a pipette to transfer 50μL of SnO2 aqueous solution and spread it evenly on the FTO conductive glass, turn on the glue machine to spin-coat the SnO2 aqueous solution, and after spin coating, move the FTO conductive glass to the hot plate for annealing for 30 minutes to form a SnO2 film on the FTO conductive glass.

[0031] After all FTO conductive glass is annealed, store at room temperature. Use a pipette to dilute the 3,4-difluorobenzenesulfonyl chloride solution to 0 mg / mL, 1 mg / mL, 3 mg / mL, and 5 mg / mL. Stir the diluted 3,4-difluorobenzenesulfonyl chloride solution for 2 hours. Before spin-coating precursor solution 1, clean the FTO conductive glass, which has been spin-coated with SnO2, with a UV-ozone cleanser for 15 minutes. Preheat the hotplate to 70°C and 150°C, respectively. Set the spin-coating parameters: speed 1500 rpm, acceleration 750, and spin-coating time 30 seconds. After the FTO conductive glass is cleaned, it is transferred to the glove box. Use tweezers to transfer the FTO conductive glass to the turntable of the spin coater, turn on the vacuum adsorption, use a pipette to draw 80 μL of precursor solution 1 and spread it slightly on the FTO conductive glass, spin coat for 30 seconds, and move it to a 70°C hot plate for annealing for 10 to 15 seconds after the spin coating is completed. After the glass sheet cools down, move it to the turntable of the spin coater, turn on the vacuum adsorption, use a pipette to draw 100 μL of precursor solution 2 drops onto the FTO conductive glass, and spin coat immediately. Move the spin-coated FTO conductive glass to a 150°C hot plate for annealing for 15 minutes to form a perovskite film.

[0032] After annealing, the annealed FTO conductive glass was moved to the turntable of the spin coater. Vacuum was turned on and the spin coating parameters were set: speed 4000 rpm, acceleration 3000, and spin coating time 30 s. 50 μL of 3,4-difluorobenzenesulfonyl chloride solution was pipetted and evenly spread on the FTO conductive glass. After spin coating, the FTO conductive glass was moved to a hot plate and annealed for 10 minutes. This step was repeated to form a control group without 3,4-difluorobenzenesulfonyl chloride and control groups containing 1 mg / mL, 3 mg / mL, and 5 mg / mL 3,4-difluorobenzenesulfonyl chloride, respectively.

[0033] After annealing, allow the FTO conductive glass to cool to room temperature. Set the spin coater parameters to 4000 rpm, 3000 acceleration, and 30 seconds for spin coating. Move the cooled FTO conductive glass to the spin coater turntable. Turn on the vacuum suction. Use a pipette to drop 50 μL of Spinro solution onto the FTO conductive glass. Spread the solution evenly and spin coat for 30 seconds. Transfer all the spin-coated FTO conductive glass to a drying oven for oxidation for 18-24 hours.

[0034] The cathode area of ​​the battery was scraped out on the oxidized FTO conductive glass according to the mask, and the Ag electrode was deposited on the FTO conductive glass using a magnetron sputtering deposition system to prepare a perovskite solar cell.

[0035] 2. Photovoltaic performance test of perovskite solar cells

[0036] The prepared perovskite solar cell was placed in a test fixture, and the light intensity of the solar simulator was set to AM = 1.5G. The photoelectric performance of the cell was tested and analyzed using an electrochemical workstation, a computer and related software.

[0037] (1) JV curve test of perovskite solar cell

[0038] Attachment Figure 1 These are the JV curves for the control group and perovskite solar cells modified with different concentrations of 3,4-difluorobenzenesulfonyl chloride in this example. The curves demonstrate that the perovskite solar cells prepared with 3,4-difluorobenzenesulfonyl chloride exhibit superior photoelectric conversion performance. Specific performance parameters for the cells are shown in the table below.

[0039]

[0040] As shown in the table above, the short-circuit current and conversion efficiency of PSCs modified with 3,4-difluorobenzenesulfonyl chloride are significantly improved. The short-circuit current density of PSCs modified with 3 mg / mL 3,4-difluorobenzenesulfonyl chloride increases by 3 mA·cm -2 This will have important implications for the field of solar cells, where device performance is paramount, and provide an important reference for the industrialization of perovskite solar cells.

[0041] (2) Long-term stability curve test of perovskite solar cells modified with the control group and 3,4-difluorobenzenesulfonyl chloride interface

[0042] Attachment Figure 2 This is a long-term stability curve test of the control group and the perovskite solar cell modified with 3 mg / mL 3,4-difluorobenzenesulfonyl chloride in this example. From the curve, it can be seen that the perovskite solar cell device with the perovskite layer / HTL interface modified with 3,4-difluorobenzenesulfonyl chloride has better long-term stability.

[0043] 3. Phase analysis and testing of perovskite thin films

[0044] (1) XRD test of the control group and the perovskite film modified with 3,4-difluorobenzenesulfonyl chloride interface

[0045] Attachment Figure 3 Figure 3 is the XRD pattern of the perovskite film modified with the control group and 3 mg / mL 3,4-difluorobenzenesulfonyl chloride interface in this example. Image analysis shows that the peak intensity of PbI2 of the perovskite film modified with 3,4-difluorobenzenesulfonyl chloride interface is significantly reduced, and the intensity of the perovskite peak is significantly increased, indicating that the perovskite modified with 3,4-difluorobenzenesulfonyl chloride interface has better crystallinity, reduces the PbI2 content at the interface, and improves the carrier transport capacity at the interface, thereby improving the efficiency of the perovskite solar cell.

[0046] For those skilled in the art, the present invention may be modified and improved without departing from the principles of the present invention, and these modifications and improvements also fall within the scope of protection of the present invention.

Claims

1. A 3,4-difluorobenzenesulfonyl chloride modified perovskite solar cell, characterized in that: Mainly include: Before preparing the hole transport layer on the perovskite layer, a layer of 3,4-difluorobenzenesulfonyl chloride solution is spin-coated on the perovskite layer and annealed to form a modified layer.

2. The method according to claim 1, characterized in that The solvent of the 3,4-difluorobenzenesulfonyl chloride is isopropyl alcohol.

3. The method according to claim 1, characterized in that The concentration of the 3,4-difluorobenzenesulfonyl chloride solution is 1-5 mg / mL.

4. The method according to claim 1, characterized in that The spin coating amount of the 3,4-difluorobenzenesulfonyl chloride solution is 40 to 60 μL.

5. The method according to claim 1, characterized in that The spin coating speed of the 3,4-difluorobenzenesulfonyl chloride solution is 3000-5000 rpm, and the spin coating time is 20-40 s.

6. The method according to claim 1, characterized in that The annealing temperature of the 3,4-difluorobenzenesulfonyl chloride solution is 90-110° C., and the annealing time is 5-15 minutes.

7. A 3,4-difluorobenzenesulfonyl chloride modified perovskite layer prepared according to the method of any one of claims 1 to 6.

8. A preparation process of a perovskite solar cell, characterized in that: The following steps are involved: Step 1: Deposit SnO2 electron transport layer on FTO / ITO conductive glass; Step 2: Preparation of FA on SnO2 electron transport layer x MA y Cs 1-x-y PbI3 perovskite layer; Step 3: preparing a 3,4-difluorobenzenesulfonyl chloride modified layer on the perovskite layer according to the method of claims 1 to 6; Step 4: Prepare a Spiro-OMeTAD hole transport layer and a metal Ag electrode on the 3,4-difluorobenzenesulfonyl chloride modified perovskite layer to obtain the perovskite solar cell.

9. The preparation method according to claims 1 to 8 can be modified and improved by a person skilled in the art without departing from the principles of the present invention, and such modifications and improvements also fall within the scope of protection of the claims of the present invention.

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