Device and method for large-area preparation of perovskite thin film in air environment

Abstract

An apparatus and method for large-area preparation of a perovskite film in an air environment, the apparatus comprising a conveying device for conveying a substrate, and a perovskite solution coating device, an anti-solvent spraying device and a drying annealing oven which are sequentially arranged along the conveying direction of the conveying device, the perovskite solution coating device is used for coating a perovskite precursor solution on a substrate, the anti-solvent spraying device is used for coating an anti-solvent on a perovskite film, and the drying annealing oven is used for drying the substrate coated with the anti-solvent; a rapid heating device and a purging device are further arranged between the perovskite solution coating device and the anti-solvent spraying device, the rapid heating device is used for heating and drying the substrate coated with the perovskite precursor solution, and the purging device is used for purging the substrate coated with the perovskite precursor solution. The method has the advantages that the safety is better, the coating effect is better, the prepared perovskite thin film is higher in quality, the photovoltaic performance of the cell is improved, and the use efficiency of the cell is improved.

Description

Technical Field

[0001] This invention relates to the field of perovskite thin films, and more particularly to an apparatus and method for preparing perovskite thin films over a large area in an air environment. Background Technology

[0002] Chinese patent document CN 108970913 B discloses a perovskite thin film coating equipment, its usage method, and its application. The perovskite thin film coating equipment includes a substrate conveying device, a perovskite solution coating device, an anti-solvent spraying device, and a drying device or a heating drying device. The perovskite solution coating device is equipped with a perovskite coating head, and the anti-solvent spraying device is equipped with an anti-solvent spray nozzle. The substrate is conveyed by the conveying device and sequentially passes through the perovskite solution coating device, the anti-solvent spraying device, and the drying device or heating drying device. The air outlet simultaneously evaporates and dries the perovskite solution and anti-solvent on the substrate surface, forming a perovskite thin film. This invention also relates to the usage method and application of this coating equipment. This invention improves upon existing one-step and two-step solution methods and their usage methods and applications, using air blowing or infrared heating to dry substrates coated with perovskite solution. This improves film quality while maintaining low production costs, making it suitable for large-scale production of perovskite thin films from substrates.

[0003] However, in the aforementioned existing perovskite thin film coating equipment, methods, and applications, the antisolvent is directly coated onto the wet film layer of the perovskite precursor during the specific operation process. Although a certain antisolvent atmosphere is provided during the drying process, direct coating of the antisolvent leads to an excessively high concentration of antisolvent on the surface, causing perovskite crystals to precipitate too quickly, hindering the evaporation of the underlying solvent, and hindering the formation of the perovskite crystal layer. At the same time, both positive solvent vapor and antisolvent vapor are present in the oven, and their effects tend to cancel each other out, which greatly affects the effect of the perovskite thin film. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a device for large-area perovskite film preparation in an air environment that offers enhanced safety, better coating results, produces higher-quality perovskite films, and improves photovoltaic performance and battery efficiency.

[0005] The present invention also provides a method for preparing perovskite thin films on a large area in an air environment, which has better safety, better coating effect, higher quality perovskite thin films, and is conducive to improving the photovoltaic performance of batteries and increasing battery efficiency.

[0006] The technical solution of this invention is as follows: An apparatus for large-area preparation of perovskite thin films in an air environment is provided, comprising a conveying device for transporting a substrate, a perovskite solution coating device, an anti-solvent spraying device, and a drying and annealing oven arranged sequentially along the conveying direction of the conveying device. The perovskite solution coating device is used to coat a perovskite precursor solution onto the substrate, the anti-solvent spraying device is used to coat the perovskite thin film with an anti-solvent, and the drying and annealing oven is used to dry the substrate after anti-solvent coating. A rapid heating device and a purging device are further provided between the perovskite solution coating device and the anti-solvent spraying device. The rapid heating device is used to heat and dry the substrate after coating with the perovskite precursor solution, and the purging device is used to purge the substrate after coating with the perovskite precursor solution.

[0007] As an improvement of the present invention, a heating device is provided below the substrate corresponding to the perovskite solution coating device.

[0008] As an improvement of the present invention, the rapid heating device is an infrared heating device.

[0009] As an improvement of the present invention, the drying temperature range of the drying annealing oven is 60℃~150℃.

[0010] As an improvement of the present invention, the purging device employs high-pressure gas purging.

[0011] As an improvement of the present invention, the conveying device is a planar conveying device or a roll-to-roll conveying device.

[0012] As an improvement of the present invention, the substrate is TCO conductive glass or ITO conductive film.

[0013] Another technical solution of the present invention is: a method for preparing perovskite thin films over a large area in an air environment, comprising the following steps: The substrate 9 is heated to 55°C-65°C using a base. The pre-prepared perovskite precursor solution is then coated onto the TiO2 or SnO2 layer using a perovskite solution coating device 2. The wet film thickness is approximately 5-15 micrometers. The drying temperature of the rapid heating device 5 is 100°C-200°C, and the purging pressure of the purging device 6 is 0.2MPa-0.3MPa. Simultaneously, the anti-solvent spraying device 3 coats the dried substrate 9 with anti-solvent, resulting in a wet film thickness of 10-20 micrometers. The coating speed is 2-3 meters per minute. The annealing temperature of the drying annealing oven 4 is selected between 60°C and 150°C.

[0014] As an improvement of the present invention, the antisolvent is at least one selected from anisole, chlorobenzene, toluene, isopropanol, ethyl acetate, ethanol, butanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, butyl acrylate, diethyl ether, m-xylene, toluene, and 1,3,5-trimethylbenzene.

[0015] As an improvement of the present invention, the substrate is TCO conductive glass or ITO conductive film.

[0016] In this invention, 1. A heating device is provided at the substrate corresponding to the perovskite solution coating device, which improves the wettability of the perovskite precursor solution on the substrate and can obtain a better coating effect.

[0017] 2. The rapid heating device adopts infrared heating and uses a closed-loop control drying system for infrared heating. In the closed-loop control drying system for infrared heating, there is penetrating power, which can heat the inside and outside at the same time, reduce the agglomeration on the perovskite surface, prevent the evaporation of the bottom solvent, make temperature control easy, and heat up rapidly, and is relatively safe.

[0018] 3. The purging device uses high-pressure gas purging, which helps solvent evaporation, optimizes the crystal structure, and improves photoelectric performance.

[0019] 4. In this invention, after rapid heating and purging, an anti-solvent is immediately applied, and then the film is placed in a drying and annealing oven with a temperature range of 60℃~150℃. The anti-solvent on the surface evaporates, providing a stable anti-solvent vapor atmosphere for the perovskite film, inducing the perovskite crystals to dissolve and grow secondary, improving the grain size and density of the film, enhancing photovoltaic performance, and increasing utilization efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of one embodiment of the apparatus for preparing perovskite thin films according to the present invention.

[0021] Figure 2 This is a schematic diagram of another embodiment of the present invention. Detailed Implementation

[0022] like Figure 1The image shows a first embodiment of an apparatus for large-area perovskite thin film preparation in an air environment according to the present invention. This apparatus is used to process a TCO conductive glass substrate 9 and includes a conveying device 1 for transporting the TCO conductive glass, a perovskite solution coating device 2, an anti-solvent spraying device 3, and a drying and annealing oven 4 arranged sequentially along the conveying direction of the conveying device 1. Preferably, in this embodiment, the conveying device 1 is a planar conveying device, the perovskite solution coating device 2 is used to coat the TCO conductive glass with a perovskite precursor solution, and the anti-solvent spraying device 3 is used for... An anti-solvent is then coated onto the perovskite film 8 on the TCO conductive glass. The drying annealing oven 4 is used to dry the TCO conductive glass after coating with the anti-solvent. A rapid heating device 5 and a purging device 6 are also provided between the perovskite solution coating device 2 and the anti-solvent spraying device 3. The rapid heating device 5 is used to heat and dry the TCO conductive glass after coating with the perovskite precursor solution. The purging device 6 is used to purge the TCO conductive glass after coating with the perovskite precursor solution. The anti-solvent spraying device 3 coats the perovskite crystal film after rapid drying with the anti-solvent. Then, the TCO conductive glass enters the drying annealing oven 4 for drying.

[0023] In this embodiment, preferably, a heating device 71 is provided below the TCO conductive glass corresponding to the perovskite solution coating device 2. Specifically, in this embodiment, the heating device 71 is a heating base. In order to improve the wettability of the precursor, the heating temperature range is 55℃~65℃. The heating device 71 improves the wettability of the perovskite precursor solution on the TCO conductive glass, and can obtain a better coating effect.

[0024] In this embodiment, preferably, the rapid heating device 5 is an infrared heating device, equipped with a temperature sensor (not visible in the figure) aligned with the TCO conductive glass surface. The temperature control range is 50°C to 300°C, with a preferred temperature range of 100°C to 200°C. The rapid heating device 5 employs a closed-loop controlled drying system with infrared heating. This system has penetrating power, allowing for simultaneous heating from the inside and outside, reducing surface agglomeration of the perovskite, hindering solvent evaporation from the bottom, facilitating temperature control, rapid heating, and enhanced safety. The purging device 6 uses high-pressure gas purging, along with a nozzle. In this embodiment, high-pressure nitrogen purging is used (although air or other inert gases can also be used, without limitation). This promotes rapid solvent evaporation, promotes uniform nucleation of the perovskite and rapid crystal growth, optimizes the crystal structure, and improves photoelectric performance.

[0025] In this embodiment, after rapid heating and purging, an anti-solvent is immediately applied, followed by placement in a drying and annealing oven 4. The temperature range of the drying and annealing oven 4 is 60°C to 150°C. The anti-solvent on the surface of the perovskite film 8 evaporates, providing a stable anti-solvent vapor atmosphere for the perovskite film 8. This induces the dissolution and secondary growth of the perovskite crystals, increasing the grain size and density of the film, thereby improving photovoltaic performance and efficiency. In this invention, different drying and annealing temperatures can be selected according to different substrates. For polyester film (PET) substrates, the annealing temperature is 80°C to 110°C; for glass or polyimide (PI) substrates, the annealing temperature is 120°C to 150°C.

[0026] The present invention can also be configured in a second embodiment (such as...) Figure 2 As shown), the second embodiment is largely the same as the first embodiment, except that, in this embodiment, preferably, the substrate 9 is an ITO conductive film, and correspondingly, the conveying device 1 is a roll-to-roll conveying device, which includes an unwinding roller 11 and a take-up roller 12. A guide roller 13 is also provided between the unwinding roller 11 and the take-up roller 12. The ITO conductive film is unwound by the unwinding roller 11 and wound up by the take-up roller 12. The heating device 71 is a heating roller.

[0027] The inventors used the method for preparing perovskite thin films of the present invention to produce perovskite solar cells (Examples 1 to 4) under laboratory conditions. In Examples 1 to 3, the substrate was TCO conductive glass, and in Example 4, the substrate was an ITO conductive film. The produced solar cells were then tested. Example

[0028] A method for preparing perovskite thin films over a large area in an air environment includes the following steps: (S1) Cutting of the substrate; Cut the FTO fluorine-doped tin oxide into the target size, with an area of ​​8cm x 8cm; (S2) Etching the circuit: Use tape to stick the part of FTO fluorine-doped tin oxide that needs to be etched, expose the part that needs to be etched, sprinkle zinc powder on the part that needs to be etched, drop hydrochloric acid on it, react for 8 seconds, and then put the FTO fluorine-doped tin oxide into a beaker containing water to clean it. (S3) Cleaning; The etched FTO fluorine-doped tin oxide was ultrasonically cleaned in sequence with glass cleaner, deionized water, acetone, isopropanol and anhydrous ethanol. (S4) Prepare the electron transport layer; take 2 ml of TiO2 precursor liquid droplet and spin coat it on FTO fluorine-doped tin oxide at 2000 rpm for 30 s, then place it in a muffle furnace for annealing at 60 ℃ for 30 s.

[0029] (S5) Prepare perovskite precursor solution; prepare PbBr2 solution (1.0 mol / L) and CsBr solution (1.0 mol / L) in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a ratio of 4:1. (S6) Coating perovskite precursor solution; heating FTO fluorine-doped tin oxide to 60°C using a substrate, coating the perovskite precursor solution onto the TiO2 layer using a perovskite solution coating device, with a wet film thickness of approximately 10 micrometers, an infrared drying temperature of 120°C, a nitrogen purging pressure of 0.3 MPa, and simultaneously coating the anti-solvent isopropanol using an anti-solvent spraying device, with a wet film thickness of 10 micrometers, a coating speed of 3 meters / minute, and an oven annealing temperature of 100°C; (S7) Prepare a hole transport layer; uniformly coat the perovskite layer with a Spiro-OMeTAD (network solid electrolyte) solution; (S8) A 100-nanometer-thick Au electrode was prepared using a vacuum evaporation method, resulting in PSCs with an effective area of ​​64 cm². 2 .

[0030] In this embodiment, preferably, the TCO conductive glass is FTO (fluorine-doped tin oxide); of course, in this invention, the TCO conductive glass can also be at least one of ITO (indium-doped tin oxide), AZO (aluminum-doped zinc oxide), ATO (aluminum-doped tin oxide), and IGO (indium-doped gallium oxide).

[0031] In this embodiment, preferably, in ABX3, A is a methylamine group, a formamidinium group, or Cs, B is Pb, Sn, or Ge, and X is I, Br, or Cl. ABX3 is formed by the reaction of a solute and a solution.

[0032] In this embodiment, preferably, the antisolvent is isopropanol. Of course, it can also be at least one of anisole, chlorobenzene, toluene, isopropanol, ethyl acetate, ethanol, butanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, butyl acrylate, diethyl ether, m-xylene, toluene, and 1,3,5-trimethylbenzene. Example

[0033] Example 2 is largely the same as Example 1, except that: (S5) Prepare perovskite precursor solution; prepare PbI2 (1.1 mol / L), FAI (1 mol / L), PbBr2 (0.2 mol / L), MABr (0.2 mol / L) solution, solvents N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the ratio of N,N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is 1:1; (S6) Heat FTO fluorine-doped tin oxide to 60°C using a substrate. Coat the perovskite precursor solution onto the TiO2 layer using a perovskite solution coating device. The wet film thickness is about 10 micrometers. The infrared drying temperature is 120°C and the nitrogen purging pressure is 0.3 MPa. At the same time, the antisolvent ethyl acetate is coated using an antisolvent spraying device. The wet film thickness is 10 micrometers. The coating speed is 3 meters / minute. The oven annealing temperature is 100°C. Example

[0034] Example 3 is largely the same as Example 1, except that: (S5) Prepare perovskite precursor solution; prepare solutions of PbI2 (1.mol / L), MAI (1mol / L), and PbBr2 (0.2mol / L) in solvents of N,N-dimethyl methyl ether (DMF) and dimethyl sulfoxide (DMSO) in a ratio of 8:1 to obtain perovskite precursor solution.

[0035] (S6) Heat FTO fluorine-doped tin oxide to 60°C using a base, and coat the perovskite precursor solution onto the TiO2 layer using a perovskite solution coating device. The wet film thickness is about 10 micrometers. The infrared drying temperature is 130°C, the nitrogen purging pressure is 0.3 MPa, and at the same time, the anti-solvent spraying device coats the anti-solvent 1,2-dichlorobenzene. The wet film thickness is 20 micrometers, the coating speed is 3 meters / minute, and the oven annealing temperature is 100°C. Example

[0036] A method for large-area preparation of perovskite thin films in an air environment. (S1) Substrate pretreatment; ITO conductive film, specifically, in this embodiment, ITO polyester film (PET). (S2) Deposit TiO2 onto the transparent electrode on the PET film; (S5) Prepare perovskite precursor solution; prepare PbI2 (1.1 mol / L), FAI (1 mol / L), PbBr2 (0.2 mol / L), MABr (0.2 mol / L) solution, the solvents being N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), wherein the ratio of N,N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is 1:1; (S6) Coating perovskite precursor solution; heating the ITO polyester film (PET) to 60°C with a heating roller, coating the perovskite precursor solution onto the TiO2 layer using a perovskite solution coating device, with a wet film thickness of about 10 micrometers, an infrared drying temperature of 120°C, a nitrogen purging pressure of 0.3 MPa, and simultaneously coating the anti-solvent toluene using an anti-solvent spraying device, with a wet film thickness of 20 micrometers, a coating speed of 3 meters / minute, and an oven annealing temperature of 100°C; (S7) Prepare a hole transport layer; uniformly coat the perovskite layer with a Spiro-OMeTAD (network solid electrolyte) solution; (S8) A 100-nanometer-thick Au electrode was prepared using vacuum evaporation. The effective area of ​​the prepared PSCs was 64 cm². 2 .

[0037] In this embodiment, preferably, the ITO conductive film is an ITO polyester film (PET) or an ITO polyimide film (PI).

[0038] In this embodiment, preferably, in ABX3, A is a methylamine group, a formamidinium group, or Cs, B is Pb, Sn, or Ge, and X is I, Br, or Cl.

[0039] In this embodiment, preferably, the antisolvent is at least one selected from anisole, chlorobenzene, toluene, isopropanol, ethyl acetate, ethanol, butanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, butyl acrylate, diethyl ether, m-xylene, toluene, and 1,3,5-trimethylbenzene.

[0040] Comparison examples: (S1) Use a glass cutter to cut the FTO conductive glass into the target size, with an area of ​​2cm × 2cm.

[0041] (S2) Use tape to attach the part of the conductive glass that needs to be etched, expose the part that needs to be etched, sprinkle zinc powder evenly on it, and use a dropper to drip hydrochloric acid. After 8 seconds, you can put the glass into a beaker of water to wash it and remove the attached hydrochloric acid.

[0042] (S3) Then, ultrasonically clean the glass in sequence with glass cleaner, deionized water, acetone, isopropanol, and anhydrous ethanol. (S4) Prepare the electron transport layer by taking 2 ml of TiO2 precursor liquid and spin-coating it onto the glass at 2000 rpm for 30 s. Then anneal it in a muffle furnace at 500 ℃ for 2 h.

[0043] (S5) Prepare a PbBr2 solution (1.0 mol / L) and a CsBr solution (1 mol / L) using N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) as solvents, wherein the ratio of N,N-dimethylformamide (DMF) to dimethyl sulfoxide (DMSO) is 4:1, to obtain a perovskite precursor solution.

[0044] (S6) Spin-coat PbBr2 solution onto glass at 2000 rpm for 30 s, bake at 80°C for 30 min, allow to cool naturally, then spin-coat CsBr solution at 2000 rpm for 30 s. Bake at 250°C for 5 min. Allow to cool naturally, then spin-coat CsBr solution, anneal, and repeat 5 times.

[0045] (S7) Prepare a hole transport layer on the perovskite coating by uniformly coating Spiro-OMeTAD solution on the perovskite layer. (S8) A 100-nanometer-thick Ag electrode was prepared using vacuum evaporation, and the effective area of ​​the prepared PSCs was 4 cm². 2 .

[0046] Experimental Analysis: Experiment 1 Table 1 below compares the battery conversion efficiencies of Examples 1 to 4 and the comparative examples:

[0047] As shown in Table 1 above, the battery in Example 2 has the highest conversion efficiency, while the battery in the comparative example has the lowest conversion efficiency. Furthermore, the battery conversion efficiencies of Examples 1 to 4 are all superior to those of the comparative example. The comparative example involved directly coating the antisolvent onto the wet film layer of the perovskite precursor. Therefore, it is evident that the battery made from the perovskite thin film prepared using the method of this invention has a higher conversion efficiency.

[0048] Experiment 2: The battery performance parameters of Examples 1 to 4 and the comparative examples are shown in Table 2 below (open-circuit voltage Voc, short-circuit current Isc, fill factor FF, conversion efficiency PCE):

[0049] As shown in Table 2 above, in terms of open-circuit voltage Voc, short-circuit current Isc, fill factor FF, and conversion efficiency PCE, the cells of Examples 1 to 4 all outperform the comparative examples in terms of conversion efficiency. Therefore, it is evident that the perovskite thin film prepared using the method of this invention produces batteries of higher quality.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An apparatus for large-area preparation of perovskite thin films in an air environment, comprising a conveying device (1) for conveying a substrate (9), a perovskite solution coating device (2), an anti-solvent spraying device (3), and a drying and annealing oven (4) arranged sequentially along the conveying direction of the conveying device (1), wherein the perovskite solution coating device (2) is used to coat a perovskite precursor solution onto the substrate, the anti-solvent spraying device (3) is used to coat an anti-solvent onto the perovskite thin film, and the drying and annealing oven (4) is used to dry the substrate after coating with the anti-solvent; characterized in that: A rapid heating device (5) and a purging device (6) are provided between the perovskite solution coating device (2) and the anti-solvent spraying device (3). The rapid heating device (5) is used to heat and dry the substrate after coating with the perovskite precursor solution, and the purging device (6) is used to purge the substrate after coating with the perovskite precursor solution.

2. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 1, characterized in that: A heating device (71) is provided below the substrate corresponding to the perovskite solution coating device (2).

3. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 2, characterized in that: The rapid heating device (5) is an infrared heating device.

4. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 3, characterized in that: The drying temperature of the drying and annealing oven (4) is selected between 60°C and 150°C.

5. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 4, characterized in that: The purging device (6) uses high-pressure gas purging.

6. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 5, characterized in that: The conveying device (1) is a planar conveying device or a roll-to-roll conveying device.

7. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 6, characterized in that: The substrate (9) is TCO conductive glass or ITO conductive film.

8. A method for preparing perovskite thin films over a large area in an air environment as described in any one of claims 1 to 7, characterized in that: Includes the following steps: The substrate (9) is heated to 55°C-65°C using a base. The pre-prepared perovskite precursor solution is coated onto the TiO2 or SnO2 layer using a perovskite solution coating device (2). The wet film thickness is approximately 5-15 micrometers. The drying temperature of the rapid heating device (5) is 100°C-200°C. The purging pressure of the purging device (6) is 0.2MPa-0.3MPa. At the same time, the anti-solvent spraying device (3) coats the dried substrate (9) with anti-solvent. The wet film thickness is 10-20 micrometers. The coating speed is 2-3 meters / minute. The annealing temperature of the drying annealing oven (4) is selected between 60°C and 150°C.

9. The method for large-area preparation of perovskite thin films in an air environment according to claim 8, characterized in that: The antisolvent is at least one selected from anisole, chlorobenzene, toluene, isopropanol, ethyl acetate, ethanol, butanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, butyl acrylate, diethyl ether, m-xylene, toluene, and 1,3,5-trimethylbenzene.

10. The apparatus for large-area preparation of perovskite thin films in an air environment according to claim 8, characterized in that: The substrate (9) is TCO conductive glass or ITO conductive film.

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