Perovskite thin film preparation device and method, and perovskite solar cell

Abstract

The application belongs to the technical field of perovskite solar cell, and provides a perovskite thin film preparation device, a perovskite thin film preparation method and a perovskite solar cell. The perovskite thin film preparation device comprises a perovskite coating device, which is used for coating a perovskite precursor solution on a substrate to form a perovskite wet film on the substrate; an extraction container, which contains an anti-solvent containing an additive; a transfer device, which is used for transferring the substrate on which the perovskite coating device coats the perovskite wet film into the extraction container, so that the perovskite wet film is soaked in the anti-solvent containing the additive; and an ultrasonic heating device, which is used for performing ultrasonic vibration treatment and heating treatment on the anti-solvent in the extraction container, so that the perovskite wet film is crystallized to obtain a perovskite thin film. The perovskite thin film preparation device can improve the crystallization quality of the prepared perovskite thin film, thereby improving the photoelectric conversion efficiency of the perovskite solar cell using the perovskite thin film.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of perovskite solar cells, and particularly relates to a perovskite thin film preparation device and method and a perovskite solar cell. BACKGROUND

[0002] With the increasing depletion of chemical fuel resources, the development and utilization of new energy has become the eternal research direction in the 21st century. The characteristics of solar energy, such as simplicity, safety, non-pollution, inexhaustibility and so on, have become a research hotspot in the past century. Since the last century, crystalline silicon solar cells, amorphous silicon solar cells and thin film solar cells have gradually appeared in the field of vision of human beings, and the high cost has also promoted the emergence of a new generation of high-efficiency solar cells. As the first generation of solar cells, the crystalline silicon cell is constantly approaching its 29.4% conversion efficiency limit. In order to break through the efficiency bottleneck and reduce the manufacturing cost of solar cells, researchers have turned their attention to the third generation of solar cells, perovskite solar cells. The emergence of perovskite solar cells has pointed out a new direction for the development of the photovoltaic industry. High efficiency and low cost have become the label of perovskite solar cells. Since 2009, in just 12 years, the conversion efficiency of perovskite solar cells has increased rapidly from 3.8% to 25.5%. Although the photoelectric conversion efficiency of perovskite solar cells can rival traditional silicon solar cells, as the area of perovskite increases, the quality of perovskite thin film decreases, which in turn leads to the photoelectric performance of perovskite solar cells, and thus restricts the industrialization process of perovskite.

[0003] In the prior art, the equipment for preparing perovskite thin film of perovskite solar cells mainly includes a perovskite coating device and an annealing device. The perovskite coating device uses a spin coating method, a slot coating, a spraying or a linear vacuum coating method to prepare a perovskite wet film on a substrate, and then the perovskite wet film is annealed by using the annealing device to crystallize the perovskite wet film to obtain a perovskite thin film. However, the perovskite thin film obtained by directly annealing the perovskite wet film will have many voids, and these voids will become the recombination center of carriers, resulting in poor quality of the perovskite thin film, low hole and electron transport efficiency, and thus low photoelectric conversion efficiency of the perovskite solar cell. SUMMARY

[0004] The present application provides a perovskite thin film preparation device, which aims to solve the problem of low photoelectric conversion efficiency of perovskite solar cells caused by the poor quality of perovskite thin film prepared by the perovskite thin film preparation device in the prior art.

[0005] The present application is implemented in the following manner. A perovskite thin film preparation device is provided, which comprises:

[0006] a perovskite coating device, configured to coat a perovskite precursor solution on a substrate to form a perovskite wet film on the substrate;

[0007] An extraction vessel containing an antisolvent containing additives, the antisolvent being used as a solvent for extracting the perovskite precursor solution of the perovskite wet film;

[0008] A transfer device for transferring the substrate coated by the perovskite coating apparatus to form the perovskite wet film into the extraction vessel, so that the perovskite wet film is immersed in the antisolvent containing the additive; and

[0009] An ultrasonic heating device is used to subject the antisolvent in the extraction container to ultrasonic vibration and heating treatment, so as to crystallize the perovskite wet film to obtain a perovskite thin film.

[0010] Preferably, the ultrasonic heating device includes:

[0011] An ultrasonic generator module is provided in the extraction container for ultrasonic vibration treatment of the antisolvent in the extraction container.

[0012] A heating module is provided in the extraction container for heating the antisolvent inside the extraction container.

[0013] Preferably, the perovskite coating apparatus includes:

[0014] Multiple coating rollers for conveying the substrate; and

[0015] A coating die head disposed above the coating roller is used to coat the substrate on the coating roller with the perovskite precursor solution.

[0016] Preferred options also include:

[0017] An antisolvent content detection device installed inside the extraction container is used to detect the content of the antisolvent inside the extraction container;

[0018] A display device connected to the antisolvent content detection device is used to display the content of the antisolvent in the extraction container in real time.

[0019] Preferred options also include:

[0020] A liquid level detection device, installed inside the extraction container and connected to the display device, is used to detect the liquid level of the antisolvent inside the extraction container. The display device is also used to display the liquid level of the antisolvent in real time.

[0021] Preferably, the solute in the perovskite precursor solution is at least one of ABX3, wherein A is a methylamine group, a formamidinium group, or Cs, B is Pb, Sn, or Ge, and X is I, Br, or Cl, and the solvent of the perovskite precursor solution is one or a combination of dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0022] 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.

[0023] Preferably, the additive is at least one selected from methylamine vapor, formamidin vapor, 1-butyl-3-methylimidazolium tetrafluoroborate, methylamine formate, methylamine acetate, 1-ethyl-3-methylimidazolium bromine, elemental iodine, and iodides.

[0024] Preferred options also include:

[0025] A horizontal moving mechanism, located at the bottom of the extraction container and below the surface of the antisolvent, is used to move the substrate coated to form the perovskite wet film from one end of the extraction container to the other end within the antisolvent.

[0026] Preferably, the substrate includes a transparent conductive underlayer and a first contact layer disposed on the transparent conductive underlayer, and the perovskite precursor solution is coated on the first contact layer to form the perovskite wet film on the first contact layer.

[0027] This invention also provides a method for preparing perovskite thin films, utilizing the aforementioned perovskite thin film preparation equipment, comprising the following steps:

[0028] The perovskite coating apparatus coats a perovskite precursor solution onto a substrate to form a perovskite wet film on the substrate.

[0029] The transfer device transfers the substrate coated to form the perovskite wet film to the extraction container containing an antisolvent containing additives, so that the perovskite wet film is immersed in the antisolvent containing the additives.

[0030] The ultrasonic heating device performs ultrasonic vibration and heating treatment on the antisolvent in the extraction container to crystallize the perovskite wet film and obtain a perovskite thin film.

[0031] Preferably, the ultrasonic wave generating power is 5-100W, and the heating temperature is 20-200℃; and / or, the ultrasonic vibration treatment and heating treatment time is 2-20 minutes.

[0032] The present invention also provides a perovskite solar cell, comprising a perovskite thin film, wherein the perovskite thin film is prepared by the above-described perovskite thin film preparation method.

[0033] The present invention provides a perovskite thin film preparation device, which includes a perovskite coating device, an extraction container, a transfer device, and an ultrasonic heating device. The perovskite coating device coats a perovskite precursor solution onto a substrate to form a perovskite wet film. The transfer device transfers the substrate with the perovskite wet film to the extraction container, where the perovskite wet film is immersed in an antisolvent. The ultrasonic heating device then performs ultrasonic vibration and heating treatment on the antisolvent in the extraction container to crystallize the perovskite wet film and obtain a perovskite thin film. By utilizing an antisolvent within an extraction vessel, combined with ultrasonic vibration and heating, a large amount of solvent in the perovskite wet film is extracted into the antisolvent, accelerating the crystallization rate of the perovskite wet film and making the perovskite film crystallization more uniform. Simultaneously, additives, in conjunction with ultrasonic vibration and heating, fill the perovskite grain boundaries and surface during the heating and crystallization process, thereby passivating the grain boundaries, reducing voids in carrier recombination centers, and minimizing defects in the perovskite film. This improves the crystallization quality of the perovskite film. Therefore, the perovskite film preparation equipment of this invention can effectively reduce defects in the prepared perovskite film, thereby improving the photoelectric conversion efficiency of perovskite solar cells using this perovskite film. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of a perovskite thin film preparation device provided in Embodiment 1 of the present invention;

[0035] Figure 2 This is a flowchart of a method for preparing perovskite thin films provided in Embodiment 2 of the present invention;

[0036] Figure 3 This is a schematic diagram of the structure of a perovskite solar cell provided in Embodiment 3 of the present invention;

[0037] Figure 4 The graph shows the open-circuit voltage-current density variation of a perovskite solar cell and a conventional perovskite solar cell, as provided in Embodiment 3 of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] The perovskite thin film preparation equipment provided in this embodiment of the invention comprises a perovskite coating device, an extraction container, a transfer device, and an ultrasonic heating device. The perovskite coating device coats a perovskite precursor solution onto a substrate to form a perovskite wet film. The transfer device transfers the substrate with the perovskite wet film to the extraction container, where the perovskite wet film is immersed in an antisolvent containing additives. The ultrasonic heating device performs ultrasonic vibration and heating treatment on the antisolvent in the extraction container to crystallize the perovskite wet film and obtain a perovskite thin film. By utilizing an antisolvent combined with ultrasonic vibration and heating treatment, a large amount of solvent in the perovskite wet film is extracted into the antisolvent, thereby accelerating the crystallization rate of the perovskite wet film and making the crystallization of the perovskite film more uniform. At the same time, the additives in the antisolvent, in conjunction with ultrasonic vibration and heating treatment, fill the perovskite grain boundaries and surface during the heating and crystallization process of the perovskite wet film, thereby passing off the grain boundaries, reducing the voids in the carrier recombination centers of the perovskite film, reducing the defects in the prepared perovskite film, thereby improving the crystallization quality of the perovskite film, and ultimately improving the photoelectric conversion efficiency of the perovskite solar cell using this perovskite film.

[0040] Example 1

[0041] Please refer to Figure 1 This embodiment provides a perovskite thin film preparation apparatus, including:

[0042] The perovskite coating apparatus 1 is used to coat a perovskite precursor solution on a substrate 10 to form a perovskite wet film 13 on the substrate 10.

[0043] Extraction container 2 contains an antisolvent 20 containing additives. The antisolvent 20 is used as a solvent for extracting the perovskite precursor solution of the perovskite wet film 13.

[0044] The transfer device 3 is used to transfer the substrate 10, which is coated by the perovskite coating device 1 to form a perovskite wet film 13, into the extraction container 2, so that the perovskite wet film 13 is immersed in an antisolvent 20 containing additives.

[0045] The ultrasonic heating device 4 is used to perform ultrasonic vibration and heating treatment on the antisolvent 20 in the extraction container 2, so as to crystallize the perovskite wet film 13 to obtain the perovskite thin film 14.

[0046] In this embodiment, the substrate 10 includes a transparent conductive underlayer and a first contact layer coated on the transparent conductive underlayer. A perovskite precursor solution is coated on the first contact layer to form a perovskite wet film 13 on the first contact layer. The first contact layer can serve as either an electron transport layer or a hole transport layer for a perovskite solar cell.

[0047] As an embodiment of the present invention, the material of the transparent conductive substrate is at least one of FTO (fluorine-doped tin oxide), ITO (indium-doped tin oxide), AZO (aluminum-doped zinc oxide), ATO (aluminum-doped tin oxide), and IGO (indium-doped gallium oxide).

[0048] As an embodiment of the present invention, the first contact layer may be at least one of N-type semiconductor SnO2, TiO2, ZnSnO4 or P-type semiconductor Spiro-oMeTad, NiO, CuSCN.

[0049] As an embodiment of the present invention, the solute of the perovskite precursor solution is at least one of ABX3, wherein A is a methylamine group, a formamidinium group or Cs, B is Pb, Sn or Ge, X is I, Br or Cl, and the solvent of the perovskite precursor solution is one or a combination of dimethylformamide, dimethyl sulfoxide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0050] In a preferred embodiment of the present invention, the solutes of the perovskite precursor solution are lead iodide and methyl ammonium iodide, and the solvents of the perovskite precursor solution are dimethylformamide (DMF) and dimethyl sulfoxide (DMSO).

[0051] As an embodiment of the present invention, the preparation process of the perovskite precursor solution specifically includes: dissolving lead iodide and methyl ammonium iodide in a molar ratio of 1:1 in a mixed solution of DMF and DMSO in a volume ratio of 1:1 and mixing them evenly to obtain the perovskite precursor solution.

[0052] As an embodiment of the present invention, the perovskite coating apparatus 1 includes:

[0053] Multiple coating rollers 11 for conveying substrate 10; and

[0054] The coating die 12, positioned above the coating roller 11, is used to coat the substrate 10 on the coating roller 11 with a perovskite precursor solution to form a perovskite wet film 13 on the substrate 10.

[0055] In this embodiment, multiple coating rollers 11 are driven to rotate by a drive device to continuously transport the substrate 10 toward the coating die head 12. The substrate 10 moves to the area below the coating die head 12 to coat with a perovskite precursor solution to obtain a perovskite wet film 13. The coating rollers 11 then continue to transport the substrate 10 coated with the perovskite wet film 13 forward. The substrate 10 coated with the perovskite wet film 13 is transferred to the extraction container 2 by the transfer device 3 for subsequent crystallization process of the perovskite wet film 13.

[0056] In this embodiment, the coating die 12 can specifically apply a layer of perovskite precursor solution to the substrate 10 by using slit coating, scraping, spin coating, printing, spraying, or vacuum coating processes to form a perovskite wet film 13 on the substrate 10.

[0057] In this embodiment of the invention, due to the difference in solubility of the perovskite precursor in the antisolvent 20 and the perovskite precursor solution, after the substrate 10 coated with the perovskite wet film 13 is placed in the antisolvent 20 containing additives, a large amount of solvent (DMF / DMSO solvent) in the perovskite wet film 13 is extracted from the perovskite wet film 13 into the antisolvent 20, thereby promoting the crystallization rate of the perovskite wet film 13. Simultaneously, during the heating and crystallization process of the perovskite wet film 13, the additives, in conjunction with ultrasonic vibration treatment, fill the perovskite grain boundaries and surface, thereby passivating the grain boundaries, reducing voids in the perovskite film's carrier recombination centers, reducing perovskite film defects, and thus improving the crystallization quality of the perovskite film, thereby improving the photoelectric conversion efficiency of the perovskite solar cell using this perovskite film.

[0058] In operation, the perovskite thin film preparation equipment of this invention uses a perovskite coating device 1 to coat a perovskite precursor solution onto a substrate 10 to form a perovskite wet film 13. The substrate 10 coated with the perovskite wet film 13 is then transferred to an extraction container 2 using a transfer device 3, so that the perovskite wet film 13 is completely immersed in the antisolvent 20. The antisolvent 20 in the extraction container 2 is simultaneously subjected to ultrasonic vibration and heating treatment by an ultrasonic heating device 4, so that the perovskite wet film 13 is completely crystallized to obtain a perovskite thin film 14.

[0059] Due to the difference in solubility of the perovskite precursor in the antisolvent 20 and the perovskite precursor solution, after the perovskite wet film 13 is placed in the antisolvent 20 containing additives, a large amount of solvent (DMF / DMSO solvent) in the perovskite wet film 13 will be extracted from the perovskite wet film 13 into the antisolvent 20. Moreover, the perovskite wet film 13, which has just entered the antisolvent 20, reacts with the antisolvent 20 to rapidly form a perovskite intermediate (perovskite-DMSO intermediate). The perovskite intermediate adheres to the substrate surface to prevent it from being dispersed and detached from the substrate surface by ultrasonic waves. Because the antisolvent 20 is continuously irradiated by ultrasound, the micro-gas within it expands rapidly under a certain degree of sound pressure, then suddenly closes. During this process, the instant the bubbles close, a shock wave is generated, creating high pressure and localized high temperature around the bubbles. This causes the residual polar solvent molecules in the perovskite intermediate phase to be rapidly extracted into the antisolvent 20, reducing the amount of precursor solvent remaining in the perovskite wet film 13 and the perovskite intermediate phase. This reduces the interference of residual solvent on crystal growth. The antisolvent 20 creates a microenvironment for perovskite crystal growth, preventing the loss of volatile components from the entire perovskite film at the required stoichiometric ratio. During perovskite grain nucleation, the traditional top-down crystallization method is avoided; instead, nucleation occurs from the inside out. The direction of crystal nucleation is the same as the direction of solvent evaporation, reducing solvent interference with crystal nucleation and accelerating the solvent extraction process. This, in turn, accelerates the crystallization of the perovskite wet film 13 and makes the crystallization of the perovskite wet film 13 more uniform.

[0060] Simultaneously, during the solvent extraction of the perovskite precursor solution of the perovskite wet film 13 into the antisolvent 20, the antisolvent 20 is subjected to ultrasonic vibration and heating treatment by the ultrasonic heating device 4, achieving complete crystallization of the perovskite wet film 13. Moreover, the ultrasonic vibration causes the bubbles of the antisolvent 20 to carry a large number of additive molecules into the surface of the perovskite intermediate. The additive molecules in the heated state randomly fill the perovskite grain boundaries and surface, which plays a role in passivating the grain boundaries, reducing the voids of carrier recombination centers in the perovskite film, reducing defects in the perovskite film, thereby improving the crystallization quality of the perovskite film, and thus improving the photoelectric conversion efficiency of the perovskite solar cell using this perovskite film.

[0061] As an embodiment of the present invention, the ultrasonic heating device 4 includes:

[0062] An ultrasonic generator module 41 is provided in the extraction container 2 for ultrasonic vibration treatment of the antisolvent 20 in the extraction container 2.

[0063] The heating module 42, located in the extraction container 2, is used to heat the antisolvent 20 inside the extraction container 2.

[0064] In this embodiment, the ultrasonic generating module 41 and the heating module 42 are integrated inside the extraction container 2, or they can be integrated outside the extraction container 2. Alternatively, the ultrasonic generating module 41 and the heating module 42 can be separately disposed in the extraction container 2.

[0065] In one embodiment of the present invention, the ultrasonic power is 5-100W and the heating temperature is 20-200℃ to ensure the extraction rate of the perovskite wet film 13 and the rate at which the antisolvent 20 enters the surface of the perovskite intermediate. The ultrasonic power and heating temperature can be set according to actual needs.

[0066] In one embodiment of the present invention, the ultrasonic vibration treatment and heating treatment time is 2-20 minutes. The ultrasonic generation module 41 and the heating module 42 operate synchronously, placing the perovskite wet film 13 in the antisolvent 20 for ultrasonic and heating treatment for 2-20 minutes. This ensures that the solvent in the perovskite precursor solution of the perovskite wet film 13 can be fully extracted, and that the additives can be effectively filled onto the surface of the perovskite crystal nuclei, thereby effectively improving the quality of the perovskite film. Furthermore, the heating treatment time of 2-20 minutes allows for complete crystallization of the perovskite wet film 13 while avoiding damage to the perovskite film structure due to excessive heating time, further improving the quality of the perovskite film.

[0067] As an embodiment of the present invention, the perovskite thin film preparation apparatus further includes:

[0068] The antisolvent content detection device 6 installed in the extraction container 2 is used to detect the content of antisolvent 20 in the extraction container 2;

[0069] A display device (not shown) connected to the antisolvent content detection device 6 is used to display the content of antisolvent 20 in the extraction container 2 in real time.

[0070] In a preferred embodiment of the present invention, the content of antisolvent 20 in the extraction container 2 is 0.1-1 mol / L. Due to the volatilization of antisolvent 20 and its repeated use in extractions, the content of antisolvent 20 in the extraction container 2 will change. Therefore, by setting up an antisolvent content detection device to detect the content of antisolvent 20 in the extraction container 2, and displaying the content of antisolvent 20 in the extraction container 2 in real time through a display device, personnel can easily know the content of antisolvent 20, allowing for timely replacement of the antisolvent 20 in the extraction container 2, maintaining the content of antisolvent 20 within the required range, and ensuring good extraction effect of antisolvent 20.

[0071] In a preferred embodiment of the present invention, when the perovskite wet film 13 is placed in the extraction container 2, the liquid level of the antisolvent 20 in the extraction container 2 is 1-10 cm higher than the upper surface of the perovskite wet film 13, so as to ensure that the antisolvent 20 in the extraction container 2 completely soaks the perovskite wet film 13.

[0072] As one embodiment of the present invention, the perovskite thin film preparation apparatus further includes:

[0073] The liquid level detection device 7, which is installed inside the extraction container 2 and connected to the display device, is used to detect the liquid level of the antisolvent 20 inside the extraction container 2. The display device is also used to display the liquid level of the antisolvent 20 in real time.

[0074] In this embodiment, the liquid level detection device 7 is set to detect the liquid level of the antisolvent 20 in the extraction container 2, and the liquid level in the extraction container 2 is displayed in real time by the display device. This allows personnel to add antisolvent 20 to the extraction container 2 as needed when the liquid level is found to be lower than the preset value, so that the antisolvent 20 can completely soak the perovskite wet film 13 and ensure the extraction effect of the antisolvent 20.

[0075] In one embodiment of the present invention, the antisolvent 20 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. Utilizing the high thermal conductivity and low viscosity of the antisolvent 20, the extraction effect of the antisolvent 20 on the solvent in the perovskite wet film 13 is ensured. Furthermore, the antisolvent 20 can be used to achieve uniform heating of the perovskite wet film 13, ensuring the crystallinity quality of the perovskite film. The antisolvent 20 can be selected according to the actual application.

[0076] As an embodiment of the present invention, the additive is at least one selected from methylamine vapor, formamidin vapor, 1-butyl-3-methylimidazolium tetrafluoroborate, methylamine formate, methylamine acetate, 1-ethyl-3-methylimidazolium bromine, elemental iodine, and iodides.

[0077] The specific type and concentration of the additive can be set according to the actual application. When the additive is a steam additive, the antisolvent 20 is a saturated solution of the steam additive to ensure the extraction effect of the antisolvent 20; when the additive is a solid additive, the solid additive can be dissolved and settled by grinding with a ball mill / agate mortar and pestle, and the clear upper layer solution is taken to ensure the extraction effect of the antisolvent 20 on the solvent in the perovskite wet film 13.

[0078] As an embodiment of the present invention, when the additive is a solid additive, the concentration of the solid additive is 1 mg / mL-10 mg / mL.

[0079] As an embodiment of the present invention, the perovskite thin film preparation apparatus further includes:

[0080] The horizontal moving mechanism 8 is located at the bottom of the extraction container 2 and is below the surface of the antisolvent 20. It is used to move the substrate 10, which is coated to form the perovskite wet film 13, from one end of the extraction container 2 to the other end of the extraction container 2 within the antisolvent 20.

[0081] In this embodiment, during the extraction process of the perovskite wet membrane 13 in the extraction container 2, the horizontal moving mechanism 8 drives the perovskite wet membrane 13 to move from one end of the extraction container 2 to the other end of the extraction container 2 in the antisolvent 20, so that the perovskite wet membrane 13 moves and extracts at the same time, which can make the antisolvent 20 and the perovskite wet membrane 13 fully contact each other and accelerate the extraction speed. Moreover, the horizontal moving mechanism 8 can simultaneously and sequentially transport multiple perovskite wet membranes 13, which can speed up the production cycle and improve production efficiency.

[0082] In this embodiment, the horizontal moving mechanism 8 is specifically a plurality of rollers arranged at intervals from one end of the extraction container 2 to the other end of the extraction container 2 at the bottom. The plurality of rollers are driven to rotate by a driving mechanism so that the plurality of rollers drive the perovskite wet film 13 to move from one end of the extraction container 2 to the other end of the extraction container 2 in the antisolvent 20.

[0083] In this embodiment, the transfer device 3 places the substrate 10, which is coated by the perovskite coating device 1 to form a perovskite wet film 13, on a portion of the rollers near one end of the extraction container 2. Multiple rollers move simultaneously to drive the perovskite wet film 13 to move from one end of the extraction container 2 to the other end of the extraction container 2 in the antisolvent 20 until the perovskite wet film 13 moves to the other end of the extraction container 2, at which point the crystallization of the perovskite wet film 13 is just completed.

[0084] The perovskite wet film 13 moves at a speed of 1-100 mm / min, and the length of the extraction container 2 can be set according to actual needs.

[0085] As an embodiment of the present invention, the transfer device 3 is specifically a mobile manipulator. A first guide rail 30 is provided between the perovskite coating device 1 and the extraction container 2. The mobile manipulator is movably disposed on the first guide rail 30 and can move back and forth between the perovskite coating device 1 and the extraction container 2 along the first guide rail 30 to transfer the substrate 10 coated to form a perovskite wet film 13 into the extraction container 2.

[0086] As an embodiment of the present invention, the perovskite thin film preparation apparatus further includes:

[0087] The extraction device 9, installed in the extraction container 2, is used to remove the substrate 10, from which the crystallized perovskite film is obtained, from the extraction container 2 to the next process platform.

[0088] As an embodiment of the present invention, the extraction device 9 is also a mobile robotic arm. A second guide rail 90 is provided between the perovskite coating device 1 and the extraction container. The mobile robotic arm is movably positioned on the second guide rail 90 and can move back and forth along the second guide rail 90 to remove the substrate 10 of the crystallized perovskite thin film from the extraction container 2 to the next process platform for the next processing step of the perovskite solar cell, and can realize the full automation of perovskite thin film preparation.

[0089] The perovskite thin film preparation equipment provided in this embodiment of the invention comprises a perovskite coating device, an extraction container, a transfer device, and an ultrasonic heating device. The perovskite coating device coats a perovskite precursor solution onto a substrate to form a perovskite wet film. The transfer device then transfers the substrate with the perovskite wet film to the extraction container, where the perovskite wet film is immersed in an antisolvent. The ultrasonic heating device then performs ultrasonic vibration and heating treatment on the antisolvent in the extraction container to crystallize the perovskite wet film and obtain a perovskite thin film. By utilizing an antisolvent combined with ultrasonic vibration and heating treatment, a large amount of solvent in the perovskite wet film is extracted into the antisolvent, thereby accelerating the crystallization rate of the perovskite wet film. Simultaneously, additives, in conjunction with ultrasonic vibration and heating treatment, fill the perovskite grain boundaries and surface during the heating and crystallization process of the perovskite wet film, thereby passivating the grain boundaries, reducing voids in the carrier recombination centers of the perovskite film, and reducing defects in the perovskite film. Therefore, the perovskite thin film preparation equipment of this invention can effectively reduce the defects of the prepared perovskite thin film, thereby improving the photoelectric conversion efficiency of perovskite solar cells using this perovskite thin film.

[0090] Example 2

[0091] Please refer to Figure 2 The present invention also provides a method for preparing perovskite thin films, using the perovskite thin film preparation equipment of the above-described Example 1. This method includes the following steps:

[0092] Step S1: The perovskite coating apparatus 1 coats a perovskite precursor solution onto the substrate 10 to form a perovskite wet film 13 on the substrate 10.

[0093] As an embodiment of the present invention, the solute of the perovskite precursor solution is at least one of ABX3, wherein A is a methylamine group, a formamidinium group or Cs, B is Pb, Sn or Ge, X is I, Br or Cl, and the solvent of the perovskite precursor solution is one or a combination of dimethylformamide and dimethyl sulfoxide.

[0094] As an embodiment of the present invention, the perovskite coating apparatus 1 can coat a layer of perovskite precursor solution onto the substrate 10 by using a slot coating process, a blade coating process, a spin coating process, a printing process, a spray coating process or a vacuum coating process to form a perovskite wet film 13 on the substrate 10.

[0095] In a preferred embodiment of the present invention, the thickness of the perovskite wet film 13 is 300-600 nm.

[0096] In step S2, the transfer device 3 transfers the substrate 10 coated to form the perovskite wet film 13 to the extraction container 2 containing the antisolvent 20 containing additives, so that the perovskite wet film 13 is immersed in the antisolvent containing additives.

[0097] In a preferred embodiment of the present invention, the antisolvent 20 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.

[0098] As an embodiment of the present invention, the additive is at least one selected from methylamine vapor, formamidin vapor, 1-butyl-3-methylimidazolium tetrafluoroborate, methylamine formate, methylamine acetate, 1-ethyl-3-methylimidazolium bromine, elemental iodine, and iodides.

[0099] In step S3, the ultrasonic heating device 4 performs ultrasonic vibration and heating treatment on the antisolvent 20 in the extraction container 2 to crystallize the perovskite wet film 13 and obtain the perovskite thin film 14.

[0100] In one embodiment of the present invention, the ultrasonic power is 5-100W and the heating temperature is 20-200℃ to ensure the extraction rate of the perovskite wet film 13 and the rate at which the antisolvent 20 enters the surface of the perovskite intermediate. The ultrasonic power and heating temperature can be set according to actual needs.

[0101] As an embodiment of the present invention, the ultrasonic vibration treatment and heating treatment time is 2-20 minutes, that is, the ultrasonic generating module 41 and the heating module 42 work for 2-20 minutes to ensure that the solvent of the perovskite precursor solution of the perovskite wet film 131 can be fully extracted and that the additives can be effectively filled to the surface of the perovskite crystal nuclei, so as to effectively improve the quality of the perovskite film. Moreover, the heating treatment time is controlled within 2-20 minutes, which can achieve complete crystallization of the perovskite wet film 13 and avoid damage to the structure of the perovskite film caused by excessive heating time, thereby further improving the quality of the perovskite film.

[0102] In this step, the antisolvent in the extraction container 2 is subjected to ultrasonic vibration and heating treatment using an ultrasonic heating device 4 to crystallize the perovskite wet film 13 and obtain a perovskite thin film. The antisolvent, combined with ultrasonic vibration and heating treatment, extracts a large amount of solvent from the perovskite wet film 13 into the antisolvent, accelerating the crystallization rate of the perovskite wet film 13. Simultaneously, additives, in conjunction with ultrasonic vibration and heating treatment, fill the perovskite grain boundaries and surface during the heating and crystallization process of the perovskite wet film 13, thereby passivating the grain boundaries, reducing voids in the perovskite film's carrier recombination centers, reducing defects in the perovskite film, and thus improving the crystallization quality of the perovskite film. This, in turn, improves the photoelectric conversion efficiency of the perovskite solar cell using this perovskite thin film.

[0103] As an embodiment of the present invention, step S3 further includes:

[0104] The horizontal moving mechanism 8 drives the substrate 10 coated with perovskite wet film 13 to move from one end of the extraction container 2 to the other end of the extraction container 2 within the antisolvent 20.

[0105] In this embodiment, when the perovskite wet film 13 is extracted in the extraction container 2, the horizontal moving mechanism 8 drives the perovskite wet film 13 to move from one end of the extraction container 2 to the other end of the extraction container 2 within the antisolvent 20. This allows the perovskite wet film 13 to be moved while being treated by ultrasonic vibration and heating, which enables the antisolvent 20 to fully contact the perovskite wet film 13, accelerates the extraction speed, and makes the crystallization of the perovskite wet film 13 more uniform, resulting in a better quality perovskite film.

[0106] This invention provides a method for preparing a perovskite thin film. A perovskite precursor solution is coated onto a substrate using a perovskite coating device to form a wet perovskite film. The substrate with the wet perovskite film is then transferred to an extraction container using a transfer device, where the wet perovskite film is immersed in an antisolvent. An ultrasonic heating device is used to subject the antisolvent in the extraction container to ultrasonic vibration and heating treatment, causing the wet perovskite film to crystallize and obtain the perovskite thin film. The combination of antisolvent treatment, ultrasonic vibration, and heating treatment extracts a large amount of solvent from the wet perovskite film into the antisolvent, accelerating the crystallization rate. Simultaneously, additives are used in conjunction with the ultrasonic vibration and heating treatment. During the heating and crystallization process, the additives fill the perovskite grain boundaries and surface, passivating the grain boundaries and reducing voids in the perovskite film's carrier recombination centers, thus reducing defects and improving the crystallization quality of the perovskite film. This, in turn, improves the photoelectric conversion efficiency of the perovskite solar cell using this perovskite film.

[0107] Example 3

[0108] Please refer to Figure 3 The present invention also provides a perovskite solar cell, comprising a perovskite thin film 14, which is prepared by the perovskite thin film preparation method of the above-described Example 2.

[0109] Specifically, the perovskite solar cell provided in this embodiment includes:

[0110] The substrate 10 includes a transparent conductive bottom layer 101 and a first contact layer 102 disposed on the transparent conductive bottom layer 101.

[0111] A perovskite thin film 14 disposed on the first contact layer 12;

[0112] The second contact layer 15 is disposed on the perovskite thin film 14; and

[0113] An electrode layer 16 is disposed above the second contact layer 15.

[0114] In this embodiment, one of the first contact layer 102 and the second contact layer 15 is an electron transport layer, and the other is a hole transport layer. One of the first contact layer 102 and the second contact layer 15 is at least one of the N-type semiconductor SnO2, TiO2, and ZnSnO4, and the other is at least one of the P-type semiconductor Spiro-oMeTad, NiO, and CuSCN.

[0115] In addition, to demonstrate the technical effects of the perovskite solar cell of the present invention, the inventors conducted experimental tests to compare the perovskite solar cell of the present invention with those of conventional perovskite solar cells. The specific test data are shown in Table 1. In Table 1, the perovskite thin film of the control group perovskite solar cell was prepared by the conventional perovskite solar cell preparation method; the perovskite thin film of the experimental group perovskite solar cell was prepared by the perovskite solar cell preparation method of the present invention.

[0116] Table 1

[0117] Classification V oc (V) J sc (mA / cm -2 )]]> FF (%) PCE (%) Control group 0.96 22.48 63.48 13.70 Experimental group 1.02 22.55 75.32 17.32

[0118] Where Voc is the open-circuit voltage; Jsc is the current density; FF is the fill factor; and PCE is the battery conversion efficiency.

[0119] Furthermore, the open-circuit voltage-current density variation curves of the perovskite solar cell of the present invention and those of conventional perovskite solar cells are shown in the figure below. Figure 4 As shown; Figure 4 Curve A is the open-circuit voltage-current density variation curve of the perovskite solar cell of the present invention. Figure 4 Curve B represents the open-circuit voltage-current density variation curve of a traditional perovskite solar cell.

[0120] From the experimental data in Table 1 above and Figure 4 As shown in the open-circuit voltage-current density curve, compared with traditional perovskite solar cells, the perovskite solar cell of this invention has a higher open-circuit voltage, a higher current density, a larger fill factor, and a higher cell conversion efficiency.

[0121] The perovskite thin film for a perovskite solar cell provided in this invention involves immersing a wet perovskite film in an antisolvent containing additives. The film is then crystallized using the antisolvent in conjunction with ultrasonic vibration and heat treatment. On one hand, a large amount of solvent in the wet perovskite film is extracted into the antisolvent, accelerating the crystallization rate and making the crystallization more uniform. On the other hand, the additives, combined with ultrasonic vibration and heat treatment, fill the grain boundaries and surface of the perovskite film during the crystallization process, thus passivating the grain boundaries, reducing voids in carrier recombination centers, and minimizing defects. This improves the crystallization quality of the perovskite film and significantly enhances the photoelectric conversion efficiency of the perovskite solar cell.

[0122] Example 4

[0123] This invention also provides a method for preparing the perovskite solar cell of Embodiment 3 described above, comprising:

[0124] a. A first contact layer 102 is prepared on a transparent conductive substrate 101 to obtain a substrate 10;

[0125] In this embodiment of the invention, the transparent conductive substrate 101 is made of at least one of FTO (fluorine-doped tin oxide), ITO (indium-doped tin oxide), AZO (aluminum-doped zinc oxide), ATO (aluminum-doped tin oxide), and IGO (indium-doped gallium oxide). b. A perovskite thin film 14 is prepared on the substrate 10 using the perovskite thin film preparation method of Example 2.

[0126] c. Prepare a second contact layer 15 on the perovskite thin film 14;

[0127] The first contact layer 102 and the second contact layer 15 are either at least one of N-type semiconductor SnO2, TiO2, and ZnSnO4, or at least one of P-type semiconductor Spiro-oMeTad, NiO, and CuSCN.

[0128] Specifically, a second contact layer 15 is formed on the perovskite thin film 14 by spin coating. The spin coating speed is controlled at 4000-5000 rpm and the spin coating time is 25-35 seconds.

[0129] d. An electrode layer 16 is prepared on the second contact layer 15.

[0130] The electrode layer 16 has a thickness of 60-80 nm. Specifically, the electrode layer 16 is deposited on the second contact layer 15 by thermal evaporation.

[0131] This invention provides a method for preparing a perovskite solar cell. In preparing the perovskite thin film, the prepared wet perovskite film is immersed in an antisolvent containing additives. The antisolvent, combined with ultrasonic vibration and heating treatment, extracts a large amount of solvent from the wet perovskite film into the antisolvent, accelerating the crystallization rate of the wet perovskite film. Simultaneously, the additives, in conjunction with the ultrasonic vibration and heating treatment, fill the perovskite grain boundaries and surface during the heating and crystallization process, thus passivating the grain boundaries, reducing voids in the carrier recombination centers of the perovskite film, and reducing defects in the perovskite film. This improves the crystallization quality of the perovskite film and significantly enhances the photoelectric conversion efficiency of the prepared perovskite solar cell.

[0132] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A perovskite thin film preparation apparatus, characterized in that, The application relates to a perovskite coating device, an extraction container, a transfer device and an ultrasonic heating device. The perovskite coating device is used for coating a perovskite precursor solution on a substrate to form a perovskite wet film on the substrate. The extraction container is filled with an additive-containing anti-solvent which is used for extracting the solvent of the perovskite precursor solution of the perovskite wet film. The transfer device is used for transferring the substrate coated by the perovskite coating device to form the perovskite wet film into the extraction container so that the perovskite wet film is soaked in the anti-solvent. The ultrasonic heating device is used for ultrasonic vibration treatment and heating treatment of the anti-solvent in the extraction container so that the perovskite wet film is crystallized to obtain a perovskite film. The additive is at least one of methylamine vapor, formamidine vapor, 1-butyl-3-methyl imidazole tetrafluoroborate, methylamine formate, methylamine acetate, 1-ethyl-3-methyl imidazole hydrochloride, elemental iodine and iodide. 2.The perovskite thin film preparation device of claim 1, wherein The ultrasonic heating device comprises an ultrasonic generating module arranged in the extraction container and used for ultrasonic vibration treatment of the anti-solvent in the extraction container. A heating module arranged in the extraction container and used for heating treatment of the anti-solvent in the extraction container. The perovskite coating device comprises a plurality of coating rollers used for conveying the substrate and a coating die arranged above the coating rollers and used for coating the substrate on the coating rollers with the perovskite precursor solution. 3.The perovskite thin film preparation device of claim 1, wherein The application further comprises an anti-solvent content detection device arranged in the extraction container and used for detecting the content of the anti-solvent in the extraction container. A display device connected with the anti-solvent content detection device and used for displaying the content of the anti-solvent in the extraction container in real time. The application further comprises a liquid level detection device arranged in the extraction container and connected with the display device and used for detecting the liquid level of the anti-solvent in the extraction container. 4.The perovskite thin film preparation device of claim 1, wherein, The solute of the perovskite precursor solution is at least one of ABX3, wherein A is a methylamine group, a formamidine group or Cs, B is Pb, Sn or Ge, and X is I, Br or Cl. The solvent of the perovskite precursor solution is one or a combination of dimethylformamide, dimethyl sulfoxide, N, N dimethylacetamide and N-methyl pyrrolidone. The anti-solvent is at least one of anisole, chlorobenzene, toluene, isopropyl alcohol, ethyl acetate, ethanol, butanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, butyl acrylate, diethyl ether, m-xylene and 1,3,5-trimethylbenzene. 5.The perovskite thin film preparation device of claim 4, wherein, The application further comprises a horizontal moving mechanism arranged at the bottom of the extraction container and below the liquid level of the anti-solvent and used for moving the substrate coated to form the perovskite wet film in the anti-solvent from one end of the extraction container to the other end of the extraction container. ​ 6.The perovskite thin film preparation device of claim 1, wherein, ​ 7.The perovskite thin film preparation device of claim 1, wherein, ​ 8.The perovskite thin film preparation device of claim 1, wherein, ​ ​ 9.The perovskite thin film preparation device of claim 1, wherein, The substrate comprises a transparent conductive bottom layer and a first contact layer disposed on the transparent conductive bottom layer, the perovskite precursor solution is coated on the first contact layer to form the perovskite wet film on the first contact layer.

10. A method for producing a perovskite thin film using the perovskite thin film production apparatus according to any one of claims 1 to 9, characterized by, The method comprises the following steps: The perovskite coating device coats the perovskite precursor solution on the substrate to form a perovskite wet film on the substrate; The transfer device transfers the substrate coated with the perovskite wet film into the extraction container containing the anti-solvent containing additives, so that the perovskite wet film is soaked in the anti-solvent containing the additives; The ultrasonic heating device performs ultrasonic vibration treatment and heating treatment on the anti-solvent in the extraction container, so that the perovskite wet film is crystallized to obtain a perovskite thin film, and the additives cooperate with the ultrasonic vibration treatment and heating treatment, and the additives fill the perovskite grain boundary and surface to passivate the grain boundary during the heating crystallization process of the perovskite wet film.

11. The method of claim 10, wherein the perovskite thin film is prepared by a method comprising: The ultrasonic generation power is 5-100W, and the heating temperature is 20-200℃; and / or, the ultrasonic vibration treatment and heating treatment time is 2-20 minutes.

12. A perovskite solar cell, characterized by, The perovskite thin film is prepared by the perovskite thin film preparation method of claim 10 or 11.

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