Apparatus for preparing perovskite thin film and method for preparing perovskite thin film

Abstract

This invention relates to the field of perovskite solar cell technology, and discloses an apparatus and method for preparing perovskite thin films. The apparatus includes a crystallization chamber, a first switching mechanism, a filling mechanism, a support, a second vacuuming mechanism, and a first vacuuming mechanism. During the preparation of the perovskite thin film, a vaporized antisolvent is uniformly distributed in an antisolvent chamber. A wet perovskite film with a precursor liquid film is placed on the support surface. The vaporized antisolvent, uniformly distributed in the antisolvent chamber, settles uniformly to the liquid film surface of the wet perovskite film under pressure difference. By setting up an antisolvent chamber, the vaporized antisolvent is uniformly dispersed within it. Then, by opening the first switching mechanism, the vaporized antisolvent automatically and uniformly settles to the liquid film surface of the wet perovskite film under pressure difference, ensuring the uniformity of the vaporized antisolvent distribution on the liquid film surface. This effectively improves the crystallization uniformity and quality of large-area perovskite thin films, making it suitable for large-scale production of large-area perovskite thin films.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, specifically to an apparatus and method for preparing perovskite thin films. Background Technology

[0002] Currently, the antisolvent method is generally used for preparing small-area perovskite thin films in the laboratory. The principle is to reduce the solubility of the material to be crystallized in the solvent by adding an antisolvent, which has a good and rapid solvent removal effect. However, due to current operational limitations, the antisolvent method can only be used for small-area perovskite thin films. For the preparation of large-area perovskite thin films, the vacuum method is usually used to remove the solvent from the wet perovskite film. This method works by lowering the solvent boiling point by reducing the gas pressure. However, the vacuum method requires high-power vacuum pumps and sophisticated equipment.

[0003] Antisolvent-assisted vacuuming can reduce the requirements for vacuum equipment and accelerate solvent extraction efficiency. Existing technology discloses an apparatus for preparing large-area perovskite thin films, comprising a cavity, a vacuum pump, a heating device, and an antisolvent storage tank, with the antisolvent storage tank connected to the cavity via a gas pipe. During perovskite thin film preparation, a substrate with a perovskite precursor liquid film is placed in the cavity. The heating device heats the antisolvent tank, causing the antisolvent to vaporize. The vacuum pump evacuates the cavity to a negative pressure state, under which the vaporized antisolvent enters the cavity through the gas pipe.

[0004] In the aforementioned perovskite thin film device, the gaseous antisolvent enters the cavity at a single point through the gas pipe. The antisolvent is unevenly distributed inside the cavity and above the perovskite wet film, making it difficult to achieve uniform distribution of the gaseous antisolvent on a large area of ​​perovskite thin film under negative pressure, which affects the uniformity of crystallization and the crystallization quality of the perovskite thin film. Summary of the Invention

[0005] In view of this, the present invention provides an apparatus and a method for preparing perovskite thin films, in order to solve the problem that the apparatus for preparing large-area perovskite thin films in the prior art cannot make the gaseous antisolvent uniformly contact the surface of the perovskite precursor liquid film, thus affecting the poor crystallization effect of the perovskite thin film.

[0006] In a first aspect, the present invention provides an apparatus for preparing perovskite thin films, comprising:

[0007] A crystallization box includes an antisolvent chamber and a crystallization chamber located at the bottom of the antisolvent chamber, wherein the antisolvent chamber is suitable for containing a vapor antisolvent;

[0008] A first switching mechanism is disposed between the antisolvent chamber and the crystallization chamber. The first switching mechanism can switch between a first state and a second state. In the first state, the first switching mechanism is closed to isolate the antisolvent chamber and the crystallization chamber. In the second state, the first switching mechanism is open to connect the antisolvent chamber and the crystallization chamber.

[0009] The dispensing mechanism has one end connected to the antisolvent chamber, and the dispensing mechanism is adapted to dispense the antisolvent into the antisolvent chamber;

[0010] The second vacuum mechanism vaporizes and disperses the antisolvent in the antisolvent chamber through the negative pressure environment created by the second vacuum mechanism.

[0011] A carrier component is disposed within the crystallization cavity and is used to support the wet perovskite film.

[0012] The first vacuum pumping mechanism is connected to the crystallization chamber; the first vacuum pumping mechanism extracts the gas in the crystallization chamber and makes the gas pressure in the crystallization chamber less than the pressure in the antisolvent chamber; in the second state, the gaseous antisolvent in the antisolvent chamber automatically settles into the crystallization chamber under the action of pressure difference.

[0013] Beneficial effects: By setting up an antisolvent chamber, the antisolvent is first added into the antisolvent chamber, where the vaporized antisolvent is evenly dispersed. Then, the first switch mechanism is opened, allowing the vaporized antisolvent to automatically and evenly settle onto the surface of the perovskite wet film under the action of pressure difference. This ensures the uniformity of the distribution of the vaporized antisolvent on the liquid film surface, effectively improving the crystallization uniformity and crystallization quality of large-area perovskite films. It is suitable for the large-scale production of large-area perovskite films.

[0014] In one optional embodiment, a uniformly distributed plate is provided between the antisolvent chamber and the crystallization chamber. The uniformly distributed plate contains a plurality of dispersion holes. When the crystallization chamber and the antisolvent chamber are in a conductive state, the antisolvent chamber is under negative pressure, and the internal pressure of the antisolvent chamber is always greater than the internal pressure of the crystallization chamber.

[0015] Beneficial effects: Under the action of pressure difference, the gaseous antisolvent settles to the surface of the liquid film through the dispersion pores, thereby dispersing the gaseous antisolvent gas flow through the dispersion pores. This allows the antisolvent to be distributed in multiple locations and in all directions on the liquid film, further ensuring the uniformity of the antisolvent distribution on the liquid film and improving the crystallization uniformity of large-area perovskite thin films.

[0016] In one optional embodiment, the dispersion orifice is a throat-like structure that is large at both ends and small in the middle, and the vaporized antisolvent forms an accelerated airflow after passing through the dispersion orifice under the action of pressure difference and is vaporized again into a mist.

[0017] Beneficial effect: The particles of the atomized antisolvent that are re-vaporized through the dispersion holes are smaller than the vaporized antisolvent particles in the antisolvent chamber, thereby further improving the uniformity of the distribution of vaporized antisolvent on the liquid film.

[0018] In one alternative embodiment, the crystallization chamber is divided into a settling chamber and a drainage chamber by a support member, with the settling chamber corresponding to the antisolvent chamber.

[0019] It also includes a second switching mechanism, which is located in the crystallization chamber and between the settling chamber and the extraction chamber. The first vacuuming mechanism is connected to the extraction chamber. The settling chamber and the extraction chamber are separated or connected by the second switching mechanism. The second switching mechanism can switch between the third state and the fourth state.

[0020] In the third state, the second switch mechanism is closed to isolate the settling chamber from the extraction chamber. The settling chamber is separated from the antisolvent chamber and the extraction chamber. The extraction chamber is under negative pressure, and the settling chamber can be independently connected to the external environment for placing the perovskite wet film.

[0021] In the fourth state, after the perovskite wet film is placed in the settling chamber, the second switching mechanism is opened to connect the settling chamber and the extraction chamber, and the settling chamber forms a pre-negative pressure environment through the extraction chamber before the antisolvent is introduced.

[0022] Beneficial effects: Because the time window for perovskite nucleation and crystallization is short, the extraction chamber is pre-vacuumed first. After the settling chamber and the extraction chamber are connected, the settling chamber can quickly form a low-pressure state to ensure the effect of rapid solvent removal.

[0023] In one optional embodiment, the carrier further includes a barrier disposed around the bearing surface of the carrier, and a drainage channel communicating with the drainage cavity is formed between the barrier and the opening and closing surface of the first switching mechanism. The height of the bearing surface is lower than the top surface of the barrier to form a sunken settling cavity relative to the drainage channel.

[0024] The second switching mechanism seals against the enclosure to isolate the settling chamber from the extraction chamber; when the extraction chamber is in the extraction state, the solvent gas in the settling chamber flows upward to the perovskite wet film and escapes into the extraction channel.

[0025] Beneficial effects: By setting up a barrier so that the bearing surface is located below the barrier, the solvent gas flow can be drawn to the top of the perovskite film, allowing the solvent gas flow to exit the solvent cavity through the top of the barrier, preventing the solvent gas flow from damaging the film surface after molding and ensuring the crystallization quality of the perovskite film.

[0026] Secondly, the present invention also provides a method for preparing a perovskite thin film, using the apparatus for preparing a perovskite thin film according to any one of the above-mentioned methods, the method for preparing a perovskite thin film comprising the following steps:

[0027] Close the first switch mechanism, and use the second vacuum mechanism to draw negative pressure into the antisolvent chamber to the preset vaporization vacuum level. Then, inject liquid or gaseous antisolvent into the antisolvent chamber, so that the liquid antisolvent can vaporize or the gaseous antisolvent can vaporize again, and the vaporized antisolvent disperses and fills the entire antisolvent chamber.

[0028] Place the perovskite wet film on the bearing surface of the carrier;

[0029] The first vacuum pumping mechanism extracts the gas from the crystallization chamber and makes the pressure in the crystallization chamber lower than the pressure in the antisolvent chamber.

[0030] The first switch mechanism is opened to connect the antisolvent chamber and the crystallization chamber. The gaseous antisolvent in the antisolvent chamber settles to the surface of the perovskite wet film under the action of pressure difference. The precursor solvent adsorbs the gaseous antisolvent. The precursor solvent with adsorbed gaseous antisolvent evaporates and precipitates under the action of negative pressure, forming a solvent gas flow.

[0031] When the first switch mechanism is closed, the solvent gas flows out of the crystallization chamber under the action of the first vacuum mechanism.

[0032] Beneficial effects: When preparing perovskite thin films using this method, the antisolvent is first added to the antisolvent chamber, where the vaporized antisolvent is evenly dispersed. Then, the first switch mechanism is turned on, allowing the vaporized antisolvent to automatically and evenly settle onto the liquid film surface of the perovskite wet film under the action of pressure difference. This ensures the uniformity of the distribution of the vaporized antisolvent on the liquid film surface, thereby effectively improving the crystallization uniformity and the crystallization quality of the perovskite thin film.

[0033] In one optional embodiment, a uniform distribution plate is provided between the antisolvent chamber and the crystallization chamber. The uniform distribution plate includes a throat-like structure of dispersion holes that are large at both ends and small in the middle, so that the pressure inside the antisolvent chamber is always greater than the pressure inside the crystallization chamber. Under the action of pressure difference, the gaseous antisolvent passes through the dispersion holes and forms an accelerated airflow, and at the same time, it is vaporized again into a mist-like gas with smaller particles.

[0034] In one optional embodiment, a second switching mechanism is provided on the upper part of the carrier, and the second switching mechanism and the carrier divide the crystallization cavity into a settling cavity and a pumping cavity, and the first vacuuming mechanism is connected to the pumping cavity.

[0035] Before placing the perovskite wet film in the settling chamber, the following steps are also included: closing the first switch mechanism and closing the second switch mechanism to separate the settling chamber from the extraction chamber, so that the antisolvent chamber, settling chamber and extraction chamber are independent; and performing a pre-vacuum operation on the extraction chamber.

[0036] After placing the perovskite wet film onto the bearing surface inside the settling chamber, the chamber of the settling chamber is sealed.

[0037] The second switch mechanism is opened to connect the settling chamber and the extraction chamber. The settling chamber and the extraction chamber are connected, and the settling chamber is in a pre-negative pressure state. The initially escaping solvent gas flow is guided into the extraction chamber in advance.

[0038] After the settling chamber and the extraction chamber are connected and the preset extraction vacuum degree is reached to achieve a state of gas pressure balance, the second switch mechanism is closed, and then the first switch mechanism is opened. Under the action of pressure difference, the gaseous antisolvent settles onto the perovskite wet film and causes the solvent to precipitate.

[0039] After the gaseous antisolvent acts on the perovskite wet film for a preset time, the antisolvent precipitates out;

[0040] Close the first switch mechanism and then open the second switch mechanism to connect the extraction chamber and the settling chamber. The settling chamber and the extraction chamber discharge the solvent gas flow through the first vacuum mechanism.

[0041] In one alternative embodiment, the carrier further includes a enclosure disposed around the perimeter of the carrier, wherein the height of the bearing surface is lower than the top surface of the enclosure;

[0042] Before the solvent gas flows out of the settling chamber, the second switch mechanism is opened and the first switch mechanism is closed so that the solvent gas flows out of the settling chamber through the top of the enclosure above the perovskite film.

[0043] In one optional embodiment, the method for preparing the perovskite thin film includes at least one of the following conditions:

[0044] The preset vaporization vacuum degree is 2kPa-6kPa;

[0045] The preset vacuum level is 0Pa-50Pa;

[0046] The preset time is 3s-10s. Attached Figure Description

[0047] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 This is a schematic diagram of an apparatus for preparing perovskite thin films according to an embodiment of the present invention;

[0049] Figure 2 for Figure 1 Top view of a uniformly distributed plate;

[0050] Figure 3 This is a schematic diagram of the first switching mechanism being closed and the second switching mechanism being open in an apparatus for preparing perovskite thin films according to an embodiment of the present invention.

[0051] Figure 4This is a schematic diagram of the first switching mechanism being open and the second switching mechanism being closed in an apparatus for preparing perovskite thin films according to an embodiment of the present invention.

[0052] Figure 5 This is a schematic diagram of the first switching mechanism in an apparatus for preparing perovskite thin films according to an embodiment of the present invention;

[0053] Figure 6 The image shows the surface morphology of the perovskite thin film prepared in Example 1.

[0054] Figure 7 The image shows the surface morphology of the perovskite film prepared in Example 2.

[0055] Figure 8 The image shows the surface morphology of the perovskite film prepared in Example 3.

[0056] Figure 9 The image shows the surface morphology of the perovskite film prepared in Comparative Example 1.

[0057] Explanation of reference numerals in the attached figures:

[0058] 1. Crystallization box; 101. Antisolvent chamber; 102. Settling chamber; 103. Exhaust chamber; 2. First switching mechanism; 201. Drive mechanism; 202. Sleeve plate; 203. Telescopic plate; 3. Filling mechanism; 301. Liquid storage container; 302. Liquid injector; 4. Supporting component; 401. Supporting surface; 402. Enclosure; 5. First vacuuming mechanism; 501. First vacuum pump; 502. First valve; 503. First pressure gauge; 6. Distribution plate; 7. Second switching mechanism; 8. Second vacuuming mechanism; 801. Second vacuum pump; 802. Second valve; 803. Second pressure gauge; 9. Exhaust plate. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] The following is combined Figures 1 to 5 The following describes embodiments of the present invention.

[0061] According to an embodiment of the present invention, an apparatus for preparing perovskite thin films is provided, comprising a crystallization box 1, a first switching mechanism 2, a filling mechanism 3, a carrier 4, a second vacuuming mechanism 8, and a first vacuuming mechanism 5. The crystallization chamber 1 includes an antisolvent chamber 101 and a crystallization chamber located at the bottom of the antisolvent chamber 101. The antisolvent chamber 101 is suitable for containing a vapor antisolvent. A first switching mechanism 2 is located between the antisolvent chamber 101 and the crystallization chamber. The first switching mechanism 2 can switch between a first state and a second state. In the first state, the first switching mechanism 2 is closed to isolate the antisolvent chamber 101 from the crystallization chamber. In the second state, the first switching mechanism 2 is open to connect the antisolvent chamber 101 and the crystallization chamber. One end of the filling mechanism 3 is connected to the antisolvent chamber 101. The filling mechanism 3 is suitable for filling the antisolvent chamber 101 with antisolvent. A carrier 4 is located in the crystallization chamber and is used to support the perovskite wet film. A first vacuuming mechanism 5 is connected to the crystallization chamber. The first vacuuming mechanism 5 extracts the gas in the crystallization chamber and makes the gas pressure in the crystallization chamber less than the pressure in the antisolvent chamber 101. In the second state, the vapor antisolvent in the antisolvent chamber 101 automatically settles into the crystallization chamber under the action of pressure difference.

[0062] In this perovskite thin film preparation apparatus, the first switching mechanism 2 is first closed to isolate the antisolvent chamber 101 from the crystallization chamber. Then, a vaporized antisolvent or a liquid antisolvent is added to the antisolvent chamber 101 via the adding mechanism 3. The antisolvent chamber 101 is under negative pressure. The liquid antisolvent vaporizes under negative pressure to form a vaporized antisolvent, or the vaporized antisolvent vaporizes again under negative pressure. The vaporized antisolvent is uniformly distributed in the antisolvent chamber 101. The perovskite wet film with the precursor liquid film is placed on the bearing surface 401, and the first vacuum pump... The first switch mechanism 5 extracts gas from the crystallization chamber to put the crystallization chamber under negative pressure and makes the pressure of the crystallization chamber less than the pressure of the antisolvent chamber 101. The first switch mechanism 2 is opened, and the antisolvent chamber 101 is connected to the crystallization chamber. The gaseous antisolvent, which is uniformly distributed in the antisolvent chamber 101, settles uniformly to the surface of the perovskite wet film under the action of pressure difference. The precursor solvent adsorbs the gaseous antisolvent. The precursor solvent with adsorbed gaseous antisolvent evaporates and precipitates under the action of negative pressure, forming a solvent gas flow. Perovskite crystals precipitate. During this process, the first vacuum mechanism 5 continuously evacuates the vacuum to extract the solvent gas flow out of the crystallization box 1.

[0063] By setting up an antisolvent chamber 101, the first switch mechanism is closed first, and liquid or gaseous antisolvent is added into the antisolvent chamber 101. Under negative pressure, the antisolvent can evaporate at low pressure to form a gaseous state, so that the gaseous antisolvent is evenly dispersed in the antisolvent chamber 101 under negative pressure. Then, the first switch mechanism 2 is opened, so that the gaseous antisolvent automatically and evenly settles onto the surface of the perovskite wet film in a uniformly distributed manner under the action of pressure difference, ensuring the uniformity of the distribution of the gaseous antisolvent on the liquid film surface, thereby effectively improving the crystallization uniformity and the crystallization quality of the perovskite film, which is suitable for the large-scale production of large-area perovskite films.

[0064] like Figure 1 As shown, in one embodiment, a uniform distribution plate 6 is provided between the antisolvent chamber 101 and the crystallization chamber. The uniform distribution plate 6 includes a plurality of dispersion holes. When the crystallization chamber and the antisolvent chamber 101 are connected, the antisolvent chamber 101 is under negative pressure, and the internal pressure of the antisolvent chamber 101 is always greater than the internal pressure of the crystallization chamber. Under the action of pressure difference, the vaporized antisolvent settles to the surface of the liquid film through the dispersion holes, thereby dispersing the vaporized antisolvent gas flow through the dispersion holes. This allows the antisolvent to be distributed in multiple points and in all directions on the liquid film, further ensuring the uniformity of the antisolvent distribution on the liquid film, improving the quality of the perovskite film, and promoting uniform crystallization.

[0065] Optionally, the dispersion pores are throat-like structures with large ends and a small middle. Under the action of pressure difference, the gaseous antisolvent passes through the dispersion pores and forms an accelerated airflow. Through the jet action of the throat structure, it is re-vaporized into a mist with smaller particles. The particles of the re-vaporized mist antisolvent are smaller than the gaseous antisolvent particles in the antisolvent chamber, so as to further improve the dispersion of the gaseous antisolvent and its uniformity of distribution on the liquid film. At the same time, since the gaseous antisolvent is slightly accelerated, the antisolvent acts on the perovskite wet film more quickly, shortening the time for the antisolvent to settle on the wet film.

[0066] By adjusting the distance between the bearing surface and the uniformly distributed plate in the bearing component 4, the speed of the antisolvent gas flow is made relatively slow when the antisolvent gas flow acts on the surface of the perovskite wet film. This speed is close to and slightly greater than the speed of the antisolvent gas flow when it falls freely without a throat structure. The purpose is to enable the antisolvent to dissolve below the surface of the wet film, rather than just floating on the surface of the wet film. It also prevents the antisolvent floating on the surface of the wet film from being carried away by the precipitated solvent gas flow, ensuring that the antisolvent can fully contact the solvent in the perovskite wet film, thereby fully precipitating the solvent.

[0067] In this embodiment, the uniform distribution plate 6 is disposed at the bottom of the first switching mechanism 2, and the edge of the uniform distribution plate 6 is fixed to the inner wall of the crystallization box 1.

[0068] like Figure 1 , Figure 3 and Figure 4As shown, the crystallization chamber is divided into a settling chamber 102 and a suction chamber 103 by a support member 4. The settling chamber 102 corresponds to the antisolvent chamber 101. It also includes a second switching mechanism 7, which is disposed in the crystallization chamber and located between the settling chamber 102 and the suction chamber 103. The first vacuuming mechanism 5 is connected to the suction chamber 103. The settling chamber 102 and the suction chamber 103 are separated or connected by the second switching mechanism 7. The second switching mechanism 7 can switch between a third state and a fourth state. In the third state, the second switching mechanism 7 is closed to isolate the settling chamber 102 and the suction chamber 103. The settling chamber is separated from the antisolvent chamber and the suction chamber. The suction chamber is under negative pressure, and the settling chamber can be independently connected to the external environment for placing the perovskite wet film. In the fourth state, after the perovskite wet film is placed in the settling chamber, the second switching mechanism 7 is opened to connect the settling chamber 102 and the suction chamber 103. The settling chamber forms a pre-negative pressure environment through the suction chamber before the antisolvent is introduced.

[0069] In the preparation of perovskite thin films, before placing the wet perovskite film into the settling chamber 102, the first switching mechanism 2 and the second switching mechanism 7 are closed to separate the settling chamber 102 from the extraction chamber 103. The extraction chamber 103 is pre-vacuumed by the first vacuuming mechanism 5 to bring its temperature to 10Pa-200Pa, thereby reducing the initial vacuum level of the extraction chamber 103. Because the solvent in the perovskite liquid film evaporates quickly and has a short crystallization time, existing preparation devices, when preparing perovskite thin films under vacuum with antisolvent assistance, only perform the vacuuming operation after the wet perovskite film is placed in the device. This results in a long vacuuming time, leading to poor initial crystallization particles in the liquid film. This invention first pre-vacuums the extraction chamber 103. After the perovskite wet film is placed on the bearing surface in the settling chamber, the second switching mechanism can be opened to connect the settling chamber and the extraction chamber. After the settling chamber and the extraction chamber are connected and a preset extraction vacuum degree of pressure equilibrium is reached, the second switching mechanism is closed to ensure that the settling chamber is in a pre-vacuum state during the reaction, thus ensuring the crystallization effect of the liquid film in the initial stage. At the same time, due to the pre-vacuum, after the settling chamber 102 and the extraction chamber 103 are connected, the settling chamber 102 can quickly form a low-pressure state to ensure the rapid removal of solvent from the perovskite film in the initial stage. On the other hand, after crystallization is completed, since the settling chamber and the extraction chamber form a pre-negative pressure environment, the preset extraction pressure can be reached more quickly during extraction, reducing the power and equipment requirements of the first vacuum mechanism.

[0070] Optionally, in one embodiment, the crystallization box 1 is integrally formed and is a rectangular box. The first switching mechanism 2 is disposed inside the crystallization box 1, the uniform distribution plate 6 is fixed below the first switching mechanism 2, and the carrier 4 is disposed below the uniform distribution plate 6. The extraction chamber 103 surrounds the carrier 4, and the dimensions of the antisolvent chamber 101, the sedimentation chamber 102, and the extraction chamber 103 can be determined according to the dimensions of the wet film.

[0071] Optionally, in one embodiment, such as Figure 5 As shown, the first switching mechanism 2 is a telescopic mechanism. For example, the first switching mechanism 2 includes two sets of telescopic components arranged opposite each other, the two sets of telescopic components being horizontal and opposite to each other. Each set of telescopic components includes a drive mechanism 201, a sleeve plate 202, and a telescopic plate 203. The telescopic plate 203 is slidably disposed within the sleeve plate 202. The drive end of the drive mechanism 201 is connected to the telescopic plate 203. In the first state, the drive mechanism 201 drives the telescopic plate 203 to extend, and the ends of the two opposite telescopic plates 203 abut against each other, so that the first switching mechanism 2 is closed. In the second state, the drive mechanism 201 drives the telescopic plate 203 to retract, and the adjacent ends of the two telescopic plates 203 move away from each other, so that the first switching mechanism 2 is opened, and an outlet for the vaporized antisolvent to flow out is formed between the two telescopic plates 203.

[0072] Sealing rings can be provided at the ends of the two telescopic plates 203. When the first switch mechanism 2 is closed, the sealing rings of the two telescopic plates 203 abut against each other to ensure the sealing and isolation effect between the antisolvent chamber 101 and the settling chamber 102.

[0073] In other embodiments, the first switching mechanism 2 may also be a multi-stage telescopic plate 203, or the first switching mechanism 2 may include a telescopic corrugated plate and a telescopic driver, with the telescopic driver connected to the end of the corrugated plate. When the first switching mechanism 2 is closed, the driving mechanism 201 drives the corrugated plate to unfold, and when the first switching mechanism 2 is opened, the driving mechanism 201 drives the corrugated plate to retract.

[0074] The structure of the second switch structure can be the same as that of the first switch mechanism 2, except that the second switch mechanism 7 is arranged vertically.

[0075] In one embodiment, such as Figure 1 , Figure 3 and Figure 4 As shown, the support member 4 also includes a barrier 402 disposed around the support surface 401 of the support member 4. The barrier 402 is disposed below the second switching mechanism. The barrier extends towards the first switching mechanism / uniform distribution plate and is spaced apart from the first switching mechanism / uniform distribution plate. A drainage channel is formed between the barrier 402 and the opening and closing surface of the first switching mechanism 2, which is connected to the drainage cavity 103. The height of the support surface 401 is lower than the top surface of the barrier 402 to form a sunken settling cavity 102 relative to the drainage channel. The second switching mechanism 7 is sealed and abutted against the barrier 402 to isolate the settling cavity 102 from the drainage cavity 103. When the drainage cavity 103 is in the state of drainage, the solvent gas in the settling cavity 102 flows upward to the perovskite wet film and diffuses into the drainage channel.

[0076] In existing fabrication devices, the direction of the solvent gas flow is difficult to control during discharge, and the solvent gas flow can easily cause secondary damage to the surface of the perovskite film. This invention addresses this by setting up a barrier 402, ensuring that the supporting surface 401 is lower than the top surface of the barrier 402. During extraction, the negative pressure in the extraction chamber draws the solvent gas flow above the perovskite film, allowing it to exit through the extraction channel above the barrier 402. This prevents the solvent gas flow from damaging the formed film surface and ensures the crystallinity quality of the perovskite film.

[0077] Optionally, in one embodiment, the top of the enclosure 402 is provided with a groove, the second switch mechanism 7 is in a closed state, the bottom of the second switch mechanism 7 is inserted into the groove, and the bottom of the second switch mechanism 7 is provided with a sealing ring, which abuts against the bottom of the groove to ensure sealing.

[0078] Specifically, in this embodiment, such as Figure 1 As shown, the carrier 4 is a pull-out tray. The cavity wall of the crystallization box has an opening corresponding to the carrier 4 for inserting or removing the perovskite film. The carrier surface 401 is rectangular. In the pulling direction, a baffle 402 is positioned on the left and right sides of the carrier surface 401. Baffles are provided on the front and rear sides of the carrier surface 401. The carrier 4 is pulled out of the crystallization box 1, the perovskite wet film is placed on the carrier surface 401, and then the carrier 4 is pushed back into the crystallization box 1. The second switching mechanism 7 is embedded in a groove at the top of the baffle 402. The baffle, the second switching mechanism 7, and the baffle 402 seal the sides of the settling chamber 102. A sealing structure can be provided at the contact point between the carrier 4 and the box body to ensure the airtightness of the crystallization box 1.

[0079] In other embodiments, the carrier can also be fixedly mounted on the crystallization box 1, and a door panel is provided on the crystallization box 1. The perovskite wet film is placed on the carrier surface 401 by opening the door panel.

[0080] Specifically, the second vacuum pumping mechanism 8 has the same structure as the first vacuum pumping mechanism 5.

[0081] The first vacuum pumping mechanism 5 includes a first vacuum pump 501 and a first pipeline. The first pipeline is connected to the pumping chamber 103. The first vacuum pump 501 is connected to the first pipeline. The first pipeline is equipped with a first valve 502 and a first pressure gauge 503. The first pressure gauge 503 measures the pressure in the pumping chamber 103. When the pressure in the pumping chamber 103 reaches the required value, the first valve 502 is closed.

[0082] The second vacuum mechanism 8 includes a second vacuum pump 801 and a second pipeline. The second pipeline is connected to the antisolvent chamber 101, and the second vacuum pump 801 is connected to the second pipeline. The second pipeline is equipped with a second valve 802 and a second pressure gauge 803. The second pressure gauge 803 measures the pressure in the antisolvent chamber 101. When the pressure in the antisolvent chamber 101 reaches the required value, the second valve 802 is closed.

[0083] like Figure 1 As shown, an exhaust plate 9 is provided on the upper outer periphery of the enclosure 402, and an exhaust hole is provided on the exhaust plate 9. The first vacuum mechanism 5 is located below the exhaust plate 9. The exhaust plate 9 guides the airflow to exit from the top of the enclosure 402 and then flow downward through the exhaust hole to the outside of the support member 4, so as to control the airflow direction and prevent the airflow from returning to the settling chamber 102 and damaging the perovskite film. The vacuum port of the first vacuum mechanism 5, which is connected to the crystallization chamber, is located directly below the support member 4, so as to balance the air pressure and flow rate on the left and right sides of the support member.

[0084] like Figure 1 As shown, the dispensing mechanism 3 includes a liquid storage container 301 and a syringe injector 302. The liquid storage container 301 stores liquid antisolvent. The syringe injector 302 draws the antisolvent from the liquid storage container 301 and then injects the antisolvent into the antisolvent chamber 101.

[0085] In other embodiments, the filling mechanism 3 may also include a liquid storage container 301 and a heating device. The outlet end of the liquid storage container 301 is connected to the antisolvent chamber 101 through a gas pipe. The heating device heats the liquid storage container 301 so that the liquid antisolvent vaporizes and flows into the antisolvent chamber 101 through the gas pipe. After the vaporized antisolvent is added to the antisolvent chamber, it vaporizes again under negative pressure.

[0086] The antisolvents include solvents such as toluene, benzene, xylene, chlorobenzene, dichloromethane, ethyl acetate, and anisole. The vacuum required for the antisolvent chamber 101 varies depending on the type of antisolvent. The vacuum of the antisolvent chamber 101 is the gas pressure required for the antisolvent to vaporize at room temperature. The amount of antisolvent required depends on the size of the perovskite wet film surface.

[0087] The solvents used in perovskite solutions can be low-volatility solvents such as DMF, DMSO, NMP, and GBL.

[0088] According to an embodiment of the present invention, in another aspect, a method for preparing a perovskite thin film is also provided, which employs the above-described apparatus for preparing a perovskite thin film. The method for preparing a perovskite thin film includes the following steps:

[0089] The first switch mechanism 2 is closed, and the second vacuum mechanism 8 is used to draw negative pressure into the antisolvent chamber to a preset vaporization vacuum level. Then, liquid or gaseous antisolvent is injected into the antisolvent chamber 101, so that the liquid antisolvent can vaporize or the gaseous antisolvent can be vaporized again, and the vaporized antisolvent is dispersed and fills the entire antisolvent chamber 101. During this process, the second vacuum mechanism 8 controls the antisolvent chamber to always be kept within the preset vaporization vacuum level range.

[0090] The perovskite wet film is placed on the bearing surface 401 of the bearing component 4;

[0091] The first vacuum pumping mechanism 5 extracts the gas from the crystallization chamber and makes the pressure in the crystallization chamber less than the pressure in the antisolvent chamber 101.

[0092] The first switch mechanism 2 is opened to connect the antisolvent chamber 101 and the crystallization chamber. The gaseous antisolvent in the antisolvent chamber 101 settles to the surface of the perovskite wet film under the action of pressure difference. The precursor solvent adsorbs the gaseous antisolvent. The precursor solvent with adsorbed gaseous antisolvent evaporates and precipitates under the action of negative pressure, forming a solvent gas flow. The first switch mechanism 2 is closed. Under the action of the first vacuum mechanism 5, the solvent gas flow is discharged from the crystallization chamber.

[0093] When preparing perovskite thin films using this method, the antisolvent is first added to the antisolvent chamber 101, where the vaporized antisolvent is uniformly dispersed. Then, the first switch mechanism 2 is turned on, allowing the vaporized antisolvent to automatically and uniformly settle onto the liquid film surface of the perovskite wet film under the action of pressure difference. This ensures the uniformity of the distribution of the vaporized antisolvent on the liquid film surface, thereby effectively improving the crystallization uniformity and the crystallization quality of the perovskite thin film.

[0094] Optionally, a uniform distribution plate 6 is provided between the antisolvent chamber 101 and the crystallization chamber. The uniform distribution plate 6 includes throat-like dispersion holes with larger ends and a smaller middle, maintaining the pressure inside the antisolvent chamber higher than that inside the crystallization chamber. Under the pressure difference, the vaporized antisolvent passes through the dispersion holes, forming an accelerated airflow, and is simultaneously re-vaporized into a mist-like gas with smaller particles through the jet effect of the throat structure. Under the pressure difference, the vaporized antisolvent in the antisolvent chamber 101 uniformly settles to the liquid film surface of the perovskite wet film through the dispersion holes. The dispersion holes disperse the vaporized antisolvent airflow, resulting in a multi-point, all-round distribution of the antisolvent on the liquid film, further ensuring the uniformity of the antisolvent distribution on the liquid film and improving the crystallization quality of the perovskite film. At the same time, because the vaporized antisolvent is slightly accelerated, it acts on the perovskite wet film more quickly, shortening the time for the antisolvent to settle onto the wet film.

[0095] The upper part of the support member 4 is provided with a second switching mechanism 7. The second switching mechanism 7 and the support member 4 divide the crystallization chamber into a settling chamber 102 and a vacuum chamber 103. The first vacuum mechanism 5 is connected to the vacuum chamber 103.

[0096] Before placing the perovskite wet film in the settling chamber 102, the following steps are also included: closing the first switch mechanism 2 and closing the second switch mechanism 7 to separate the settling chamber 102 from the extraction chamber 103, so that the antisolvent chamber 101, the settling chamber 102, and the extraction chamber 103 are independent; and performing a pre-vacuum operation on the extraction chamber 103.

[0097] After the perovskite wet film is placed on the bearing surface 401 inside the settling chamber, the chamber of the settling chamber 102 is sealed.

[0098] The second switch mechanism 7 is opened to connect the settling chamber 102 with the extraction chamber 103. The settling chamber and the extraction chamber are connected, and the settling chamber is in a pre-negative pressure state. The initially escaping solvent gas flow is guided into the extraction chamber in advance.

[0099] After the settling chamber and the extraction chamber are connected and the preset extraction vacuum degree is reached to achieve a state of gas pressure balance, the second switch mechanism 7 is closed, and then the first switch mechanism 2 is opened. Under the action of pressure difference, the gaseous antisolvent settles onto the perovskite wet film and causes the solvent to precipitate.

[0100] After the gaseous antisolvent acts on the perovskite wet film for a preset time, the antisolvent precipitates out;

[0101] Close the first switch mechanism 2 and then open the second switch mechanism 7 to connect the extraction chamber 103 and the settling chamber 102. The settling chamber and the extraction chamber discharge the solvent gas flow through the first vacuum mechanism.

[0102] This method first pre-evacuates the extraction chamber 103. After the settling chamber 102 is connected to the extraction chamber 103, and both chambers reach a preset extraction vacuum level, the second switching mechanism is then closed. The perovskite wet film in the settling chamber 102 reacts under the preset extraction vacuum level. After the antisolvent precipitates, the first switching mechanism is closed and the second switching mechanism is opened, allowing the settling chamber 102 to quickly form a low-pressure state, thus ensuring the crystallization quality of the perovskite film in the initial stage. On the other hand, after crystallization is completed, because the settling chamber and the extraction chamber form a pre-negative pressure environment, the extraction process allows the settling chamber to reach the preset extraction pressure more quickly, reducing the power and equipment requirements of the first vacuum mechanism.

[0103] Furthermore, compared to existing technologies that place the perovskite wet film before extraction, this solution changes the order of wet film placement. By placing the perovskite wet film after pre-negative pressure is applied, the storage time of the wet film in the recrystallization chamber can be shortened. In particular, the time from atmospheric pressure to the preset negative pressure during the extraction process allows the perovskite wet film to enter the optimal environment for solvent precipitation and crystallization in the shortest possible time, eliminating the undesirable crystallization stage from atmospheric pressure to the preset negative pressure. By applying pre-negative pressure and changing the order of wet film placement, the overall time cycle can be significantly shortened, and the morphology of the crystals can be greatly improved.

[0104] The carrier 4 also includes a enclosure 402 disposed around the carrier 4, and the height of the bearing surface 401 is lower than the top surface of the enclosure 402; before the solvent gas flows out of the settling chamber 102, the second switch mechanism 7 is opened and the first switch mechanism 2 is closed, and the solvent gas flows out of the settling chamber 102 through the top of the enclosure 402 above the perovskite film.

[0105] When the solvent gas is discharged in this method, the solvent gas is discharged from the solvent chamber above the enclosure 402 to prevent the solvent gas from damaging the film surface after molding and to ensure the crystallization quality of the perovskite film.

[0106] The method for preparing perovskite thin films includes at least one of the following conditions:

[0107] The preset vaporization vacuum degree is 2kPa-6kPa;

[0108] The preset vacuum level is 0Pa-50Pa;

[0109] The preset time is 3s-10s.

[0110] Both the first switching mechanism 2 and the second switching mechanism 7 are initially in the closed state. The preparation steps of the perovskite thin film preparation method are as follows:

[0111] Open the second valve 802, and the second vacuum pump 801 will evacuate the antisolvent chamber 101 to achieve the vacuum level required for antisolvent vaporization at room temperature. For example, when the antisolvent is toluene, the vacuum level needs to be below 2 kPa-6 kPa. After the vacuum level is reached, close the second valve 802. At this time, the antisolvent chamber 101 is in a certain vacuum state.

[0112] A certain amount of liquid antisolvent is injected into the antisolvent chamber 101 through the injector 302. The liquid antisolvent is vaporized into gaseous antisolvent under a certain vacuum degree, and the gaseous antisolvent is evenly distributed in the antisolvent chamber 101.

[0113] Open the first valve 502 and start the first vacuum pump 501 to pre-evacuate the extraction chamber 103, so that the gas pressure in the extraction chamber 103 reaches 10Pa-200Pa. Open the second switch mechanism 7 to connect the settling chamber 102 and the extraction chamber 103. The settling chamber and the extraction chamber are connected, and the settling chamber is in a pre-negative pressure state. The initially escaping solvent gas flow is pre-introduced into the extraction chamber.

[0114] Pull out the support member 4 and place the perovskite wet film onto the support surface 401 inside the settling chamber 102.

[0115] The second switch mechanism 7 is opened to connect the settling chamber 102 with the extraction chamber 103. The settling chamber and the extraction chamber are connected, and the settling chamber is in a pre-negative pressure state. The initially escaping solvent gas flow is guided into the extraction chamber in advance.

[0116] After the settling chamber and the extraction chamber are connected and a preset vacuum level of air pressure balance is reached, the second switch mechanism 7 is closed, and then the first switch mechanism 2 is opened, as follows. Figure 4As shown, the antisolvent chamber 101 is connected to the settling chamber 102. At this time, since the pressure in the antisolvent chamber 101 is higher than that in the settling chamber 102, under the action of the pressure difference, the vapor antisolvent sinks from the antisolvent chamber 101 to the settling chamber 102 through the dispersion hole, so that the antisolvent is evenly distributed on the surface of the perovskite wet film. This is maintained for 3s-10s to achieve full contact between the vapor antisolvent and the wet film surface.

[0117] The first switch mechanism 2 is closed, and the second switch mechanism 7 is opened, connecting the settling chamber 102 with the extraction chamber 103. Under the action of the first vacuum pump 501, the solvent gas flow is extracted from the extraction chamber 103. This process is maintained for 30-60 seconds to ensure sufficient extraction of the solvent gas flow.

[0118] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0119] Example 1

[0120] Step 1: Inject toluene into the storage container 301, open the second valve 802 and the second vacuum pump 801 to evacuate the antisolvent chamber 101 until the vacuum level reaches below 3 kPa, and close the second valve 802; inject 2 ml of toluene into the antisolvent chamber 101 through the injector 302 to vaporize and generate toluene vapor.

[0121] Step 2: Open the first valve 502 and the first vacuum pump 501 to pre-evacuate the extraction chamber 103. When the air pressure in the extraction chamber 103 reaches below 50 Pa, remove the carrier 4 and place the coated 30*30cm perovskite wet film onto the carrier surface 401 in the settling chamber 102. Open the second switch mechanism 7. At this time, the air pressure in the settling chamber 102 and the extraction chamber 103 can reach below 50 Pa within 3s-5s.

[0122] Step 3: Close the second switch mechanism 7, open the first switch mechanism 2 and hold for 5 seconds, close the first switch mechanism 2, open the second switch mechanism 7, and the precursor solvent with adsorbed gaseous antisolvent will evaporate rapidly under negative pressure. The evaporated solvent gas flow will be discharged from the exhaust plate 9 to the exhaust chamber 103. Evacuate the exhaust chamber 103 to 50 Pa and hold for 30 seconds, then close the second switch mechanism 7, the first vacuum pump 501 and the first valve 502.

[0123] Step 4: Remove the carrier 4, take out the dried perovskite film, and anneal it in an annealing furnace at 150°C for 15 minutes.

[0124] The surface morphology of the perovskite thin film obtained in this embodiment is as follows: Figure 6 As shown.

[0125] Example 2

[0126] Except for step 3, all other steps in this embodiment are the same as in embodiment 1.

[0127] Step 3: Close the second switch mechanism 7, open the first switch mechanism 2 and hold for 3 seconds, close the first switch mechanism 2, open the second switch mechanism 7, the solvent gas flows out of the exhaust chamber 103, evacuate to 50 Pa and hold for 30 seconds, then close the second switch mechanism 7, the first vacuum pump 501 and the first valve 502.

[0128] The surface morphology of the perovskite thin film obtained in this embodiment is as follows: Figure 7 As shown.

[0129] Example 3

[0130] Except for step 3, all other steps in this embodiment are the same as in embodiment 1.

[0131] Step 3: Close the second switch mechanism 7, open the first switch mechanism 2 and hold for 10 seconds, close the first switch mechanism 2, open the second switch mechanism 7, and the precursor solvent with adsorbed gaseous antisolvent will evaporate rapidly under negative pressure. The evaporated solvent gas flow will be discharged from the exhaust plate 9 to the exhaust chamber 103. Evacuate the exhaust chamber 103 to 50 Pa and hold for 30 seconds, then close the second switch mechanism 7, the first vacuum pump 501 and the first valve 502.

[0132] The surface morphology of the perovskite thin film obtained in this embodiment is as follows: Figure 8 As shown.

[0133] Comparative Example 1

[0134] Open the second switch mechanism 7, pull out the carrier 4, place the coated perovskite wet film on the carrier surface 401, open the first valve 502 and the first vacuum pump 501, and the opening angle of the first valve 502 is the same as in Example 1, so that the air pressure of the settling chamber 102 and the exhaust chamber 103 reaches below 50Pa and is maintained for 30s.

[0135] In this comparative example, no anti-solvent treatment was performed during the perovskite film preparation process, resulting in the following perovskite film: Figure 9 As shown.

[0136] Depend on Figures 6 to 8 It can be seen that the perovskite film treated with antisolvent has a smooth surface and a larger grain size. Furthermore, the antisolvent treatment time also has a significant impact on the morphology of the perovskite film. Figure 6 As shown, when the antisolvent treatment time is appropriate, the film surface is smooth and the grain size is relatively large; Figure 7 As shown, when the antisolvent treatment time is short, the improvement effect on the film surface is not obvious; for example... Figure 8As shown, when the antisolvent treatment time is too long, the solvent gas flow will damage the perovskite film surface due to the failure to evacuate in time.

[0137] like Figure 9 As shown, for perovskite films obtained without antisolvent treatment, due to the limited vacuuming rate of the first vacuum pump 501, there are pores on the film surface and the film surface is uneven, resulting in carrier recombination.

[0138] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An apparatus for preparing perovskite thin films, characterized in that, include: A crystallization chamber includes an antisolvent chamber (101) and a crystallization chamber located at the bottom of the antisolvent chamber (101). The antisolvent chamber (101) is suitable for containing a vapor antisolvent. A uniform distribution plate (6) is provided between the antisolvent chamber (101) and the crystallization chamber. The uniform distribution plate (6) includes a plurality of dispersion holes. When the crystallization chamber and the antisolvent chamber (101) are in a conductive state, the antisolvent chamber (101) is under negative pressure, and the internal pressure of the antisolvent chamber (101) is always greater than the internal pressure of the crystallization chamber. A first switching mechanism (2) is disposed between the antisolvent chamber (101) and the crystallization chamber, and the first switching mechanism (2) can switch between a first state and a second state; In the first state, the first switching mechanism (2) is closed to isolate the antisolvent chamber (101) from the crystallization chamber; in the second state, the first switching mechanism (2) is open to connect the antisolvent chamber (101) with the crystallization chamber. The dispensing mechanism (3) is connected at one end to the antisolvent chamber (101), and the dispensing mechanism (3) is adapted to dispense antisolvent into the antisolvent chamber (101); The second vacuum mechanism (8) vaporizes and disperses the antisolvent in the antisolvent chamber (101) through the negative pressure environment formed by the second vacuum mechanism (8); The carrier (4) is disposed in the crystallization cavity and is used to support the perovskite wet film; The first vacuum pumping mechanism (5) is connected to the crystallization chamber; the first vacuum pumping mechanism (5) extracts the gas in the crystallization chamber and makes the gas pressure in the crystallization chamber less than the pressure in the antisolvent chamber (101); In the second state, the vaporized antisolvent in the antisolvent chamber (101) automatically settles into the crystallization chamber under the action of pressure difference.

2. The apparatus for preparing perovskite thin films according to claim 1, characterized in that, The dispersion pores are throat-like structures that are large at both ends and small in the middle. Under the action of pressure difference, the vaporized antisolvent passes through the dispersion pores and forms an accelerated airflow, which is then vaporized again into a mist.

3. The apparatus for preparing perovskite thin films according to claim 1 or 2, characterized in that, The crystallization chamber is divided into a settling chamber (102) and a pumping chamber (103) by the support member (4), and the settling chamber (102) corresponds to the antisolvent chamber (101). It also includes a second switching mechanism (7), which is disposed in the crystallization cavity and located between the settling cavity (102) and the extraction cavity (103). The first vacuuming mechanism (5) is connected to the extraction cavity (103). The settling cavity (102) and the extraction cavity (103) are separated or connected by the second switching mechanism (7). The second switching mechanism (7) can switch between a third state and a fourth state. In the third state, the second switch mechanism (7) is closed to isolate the settling chamber (102) from the extraction chamber (103). The settling chamber is separated from the antisolvent chamber and the extraction chamber. The extraction chamber is under negative pressure, and the settling chamber can be independently connected to the external environment for placing a perovskite wet film. In the fourth state, after the perovskite wet film is placed in the settling chamber, the second switching mechanism (7) is opened to connect the settling chamber (102) and the extraction chamber (103), and the settling chamber forms a pre-negative pressure environment through the extraction chamber before the antisolvent is introduced.

4. The apparatus for preparing perovskite thin films according to claim 3, characterized in that, The support member (4) also includes a enclosure (402) disposed around the support surface (401) of the support member (4). The enclosure (402) and the opening and closing surface of the first switching mechanism (2) form a drainage channel communicating with the drainage cavity (103). The height of the support surface (401) is lower than the top surface of the enclosure (402) to form a sunken settling cavity (102) relative to the drainage channel. The second switching mechanism (7) is sealed against the enclosure (402) to isolate the settling chamber (102) from the extraction chamber (103); when the extraction chamber (103) is being extracted, the solvent in the settling chamber (102) flows upward to the perovskite wet film and escapes into the extraction channel.

5. A method for preparing a perovskite thin film, characterized in that, The apparatus for preparing perovskite thin films according to any one of claims 1 to 4, the method for preparing perovskite thin films includes the following steps: Close the first switch mechanism (2), and use the second vacuum mechanism (8) to draw negative pressure to the antisolvent chamber to a preset vaporization vacuum degree. Then inject liquid or gaseous antisolvent into the antisolvent chamber (101) so that the liquid antisolvent can vaporize or the gaseous antisolvent can vaporize again. The vaporized antisolvent is dispersed and fills the entire antisolvent chamber (101). A uniform distribution plate (6) is provided between the antisolvent chamber (101) and the crystallization chamber. The uniform distribution plate (6) is provided with dispersion holes. The perovskite wet film is placed on the bearing surface (401) of the bearing member (4); The first vacuum pumping mechanism (5) extracts the gas in the crystallization chamber and makes the pressure in the crystallization chamber less than the pressure in the antisolvent chamber (101); The first switch mechanism (2) is opened to connect the antisolvent chamber (101) and the crystallization chamber. The gaseous antisolvent in the antisolvent chamber (101) settles to the surface of the perovskite wet film under the action of pressure difference. The precursor solvent adsorbs the gaseous antisolvent. The precursor solvent with adsorbed gaseous antisolvent evaporates and precipitates under the action of negative pressure to form a solvent gas flow. When the first switch mechanism (2) is closed, the solvent gas flows out of the crystallization chamber under the action of the first vacuum mechanism (5).

6. The method for preparing perovskite thin films according to claim 5, characterized in that, The uniformly distributed plate (6) contains a throat-like structure with large ends and a small middle, which keeps the pressure inside the antisolvent chamber greater than the pressure inside the crystallization chamber. Under the action of pressure difference, the gaseous antisolvent passes through the dispersion holes to form an accelerated airflow and at the same time vaporizes again into a mist-like gas with smaller particles.

7. The method for preparing perovskite thin films according to claim 5 or 6, characterized in that, The upper part of the support member (4) is provided with a second switching mechanism (7). The second switching mechanism (7) and the support member (4) divide the crystallization cavity into a settling cavity (102) and a pumping cavity (103). The first vacuuming mechanism (5) is connected to the pumping cavity (103). Before placing the perovskite wet film in the settling chamber (102), the following steps are also included: turning off the first switching mechanism (2) and the second switching mechanism (7) to separate the settling chamber (102) from the extraction chamber (103), so that the antisolvent chamber (101), the settling chamber (102), and the extraction chamber (103) are independent; and performing a pre-vacuum operation on the extraction chamber (103). After the perovskite wet film is placed on the bearing surface (401) inside the settling cavity, the chamber of the settling cavity (102) is sealed. The second switch mechanism (7) is opened to connect the settling chamber (102) with the extraction chamber (103). The settling chamber is connected to the extraction chamber and the settling chamber forms a pre-negative pressure state, and the initially escaping solvent gas flow is pre-introduced into the extraction chamber. After the settling chamber and the extraction chamber are connected and a preset extraction vacuum degree is reached to achieve a gas pressure balance state, the second switch mechanism (7) is closed, and then the first switch mechanism (2) is opened. Under the action of pressure difference, the gaseous antisolvent settles onto the perovskite wet film and causes the solvent to precipitate. After the gaseous antisolvent acts on the perovskite wet film for a preset time, the antisolvent precipitates out; Close the first switch mechanism (2) and then open the second switch mechanism (7) to connect the extraction chamber (103) and the settling chamber (102). The settling chamber and the extraction chamber discharge the solvent gas flow through the first vacuum mechanism.

8. The method for preparing perovskite thin films according to claim 7, characterized in that, The support member (4) also includes a enclosure (402) disposed around the support member (4), wherein the height of the support surface (401) is lower than the top surface of the enclosure (402); Before the solvent gas flows out of the settling chamber (102), the second switch mechanism (7) is opened and the first switch mechanism (2) is closed so that the solvent gas flows out of the settling chamber (102) through the top of the enclosure (402) above the perovskite film.

9. The method for preparing perovskite thin films according to claim 7, characterized in that, It contains at least one of the following conditions: The preset vaporization vacuum degree is 2kPa-6kPa; The preset vacuum level is 0Pa-50Pa; The preset time is 3s-10s.

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