Preparation method and preparation system of perovskite thin film

Abstract

The invention relates to the field of film coating equipment, in particular to a perovskite film preparation method and system, and the method comprises the steps: putting a substrate into a self-limiting groove in a substrate bearing platform, and enabling the substrate to be automatically positioned and attached to the bottom of the self-limiting groove under the action of gravity; the substrate is firmly adsorbed to the bottom of the self-limiting groove through a vacuum adsorption system; the upper surface of the substrate is subjected to wet film coating through a coating mechanism, and waste liquid generated in the coating process is discharged to a waste liquid collecting system through a waste liquid guide groove and a waste liquid guide hole in the substrate bearing platform; and after coating is completed, the wet film is subjected to in-situ annealing treatment through the heating module. According to the preparation method disclosed by the invention, the accuracy and the stability of substrate positioning are ensured, and the displacement of the substrate in a coating process is avoided; the waste liquid discharge design ensures that the coating environment is clean, and pollution is reduced; the wet film can be treated in time through in-situ annealing treatment, the high-quality perovskite thin film can be formed, and the preparation efficiency and the yield of the thin film are improved.

Description

Technical Field

[0001] The present invention relates to the field of preparation of perovskite thin films, and particularly to a method and a system for preparing perovskite thin films. Background Art

[0002] The laboratory-certified efficiency of single-junction perovskite solar cells has reached 26%, and the efficiency of meter-scale large areas in the industry has also exceeded 16%. With rapid development, its characteristics of low cost and high efficiency endow it with broad commercial prospects. Perovskite solar cells mainly consist of a transparent conductive substrate, an electron transport layer, a perovskite light-absorbing layer, a charge transport layer, a back electrode, and various functional modification layers. Among them, as the key to photoelectric conversion, the preparation method and process of the perovskite light-absorbing layer are particularly important.

[0003] At present, there are many devices for preparing large-area perovskite thin films, including slot coating devices, blade coating devices, inkjet printing devices, spraying devices, etc. Among them, slot coating and blade coating are the current mainstream preparation devices. However, in existing devices, the vertical position alignment between the substrate and the coating head is generally carried out manually. The whole process takes a long time, and for large-area substrates, the length and width travel are relatively long. Once there is a deviation in the front-end alignment, the deviation at the back-end will be even greater after coating is completed, resulting in a reduction in coating yield. Moreover, waste liquid is likely to remain at the edge of the substrate during the coating process, leading to uneven film thickness; in-situ annealing treatment of the wet film cannot be carried out. Summary of the Invention

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a method and a system for preparing perovskite thin films. The preparation method cooperatively operates through steps of self-positioning, adsorption, coating, and annealing. Each link is closely coordinated to ensure the accuracy and stability of substrate positioning, and avoid the displacement of the substrate during the coating process; the waste liquid discharge design ensures a clean coating environment and reduces pollution; the in-situ annealing treatment can timely process the wet film, which is beneficial to the formation of high-quality perovskite thin films and improves the preparation efficiency and yield of the thin films.

[0005] The first aspect of the present invention lies in providing a method for preparing perovskite thin films, including:

[0006] S10. Self-positioning step: placing the substrate into the self-positioning groove on the substrate carrying platform, and the substrate automatically positions and fits on the bottom of the self-positioning groove under the action of gravity;

[0007] S20. Adsorption step: firmly adsorbing the substrate on the bottom of the self-positioning groove through a vacuum adsorption system;

[0008] S30. Coating step: performing wet film coating on the upper surface of the substrate through a coating mechanism, and the waste liquid generated during the coating process is discharged to the waste liquid collection system through the waste liquid diversion groove and the waste liquid diversion hole on the substrate carrying platform;

[0009] S40, Annealing step: After coating is completed, the wet film is subjected to in-situ annealing treatment through a heating module.

[0010] Based on the above solution, in the self-positioning step of the present invention, gravity is used to automatically drop the substrate to the bottom of the groove to achieve initial positioning; in the adsorption step, negative pressure generated by a vacuum adsorption system is used to firmly adsorb the substrate to the bottom of the groove; in the coating step, a wet film is coated on the surface of the substrate through a coating mechanism, and the waste liquid is discharged through a diversion groove and a waste liquid diversion hole; in the annealing step, the wet film is subjected to in-situ annealing treatment by a heating module to promote the crystallization of the perovskite thin film into a film. In this way, the preparation method cooperates through the self-positioning, adsorption, coating, and annealing steps, with each link closely coordinated, ensuring the accuracy and stability of substrate positioning, and avoiding the displacement of the substrate during the coating process; the waste liquid discharge design ensures a clean coating environment and reduces pollution; the in-situ annealing treatment can promptly process the wet film, which is beneficial to the formation of high-quality perovskite thin films and improves the preparation efficiency and yield of the thin films.

[0011] In the first aspect of the present invention, as a preferred embodiment, in S10, the self-positioning step, the length and width dimensions of the self-positioning groove are 0.5 - 1 mm larger than the corresponding dimensions of the substrate, and chamfers with a radius of 0.2 - 0.5 mm are provided at the edges.

[0012] In the first aspect of the present invention, as a preferred embodiment, in S20, the adsorption step, the vacuum pressure is controlled to be (-60) - (-80) kPa.

[0013] In the first aspect of the present invention, as a preferred embodiment, in S30, the coating step, the coating speed is 8 - 20 mm / s.

[0014] In the first aspect of the present invention, as a preferred embodiment, in S40, the annealing step, in-situ annealing treatment at 80°C - 300°C is carried out, and the annealing time is 0.5 - 60 minutes.

[0015] In the first aspect of the present invention, as a preferred embodiment, in S40, the annealing step, the heating module adopts a heat conduction, heat radiation or microwave heating method.

[0016] In the first aspect of the present invention, as a preferred embodiment, it further includes S50, ejection step: After the annealing step is completed, first turn off the vacuum adsorption system, and then activate the electromagnetic columns located at the four corners of the self-positioning groove to lift the substrate, wherein the electromagnetic columns are configured to have their top surfaces flush with the bottom surface of the groove in the lowered state and eject the substrate in the raised state.

[0017] The second aspect of the present invention lies in providing a preparation system for perovskite thin films, including:

[0018] Coating device, the coating device includes a counterweight base, a coating stage and a coating mechanism, the coating stage is mounted on the counterweight base; the coating stage includes a substrate carrying platform and a heating module; a self-limiting groove is provided on the upper surface of the substrate carrying platform; a waste liquid diversion groove is provided in the self-limiting groove, and a waste liquid diversion hole communicating with the waste liquid diversion groove is provided inside the substrate carrying platform; a vacuum adsorption chamber located below the self-limiting groove is formed inside the substrate carrying platform; a plurality of vacuum adsorption holes are provided in the self-limiting groove, and the plurality of vacuum adsorption holes communicate with the vacuum adsorption chamber respectively; a vacuum extraction hole communicating with the vacuum adsorption chamber is provided on the substrate carrying platform; the heating module is provided below the vacuum adsorption chamber or at the bottom of the coating stage; the coating mechanism is mounted on the counterweight base and is located above the substrate carrying platform;

[0019] Vacuum adsorption system, the vacuum adsorption system is connected to the vacuum adsorption chamber;

[0020] Waste liquid collection system, the liquid inlet end of the waste liquid collection system is connected to the drain outlet of the waste liquid diversion hole.

[0021] In the second aspect of the present invention, as a preferred embodiment, the number of the waste liquid diversion grooves is two, and they are symmetrically distributed on the opposite sides of the self-limiting groove along the long axis direction of the substrate; the number of the waste liquid diversion holes is two, and they communicate with the two waste liquid diversion grooves respectively in one-to-one correspondence.

[0022] In the second aspect of the present invention, as a preferred embodiment, the width of the waste liquid diversion groove is 1-3 mm, the depth is 0.5-1.5 mm, and the bottom of the groove is inclined downward at 2°-6°; the waste liquid diversion hole is inclined downward at 10°-20°.

[0023] In the second aspect of the present invention, as a preferred embodiment, it further includes four electromagnetic columns, and the four electromagnetic columns are respectively arranged on the substrate carrying platform and are located at the four corners of the self-limiting groove. The four electromagnetic columns are configured to be controlled by an electromagnetic system to switch between a rising state and a falling state; when the four electromagnetic columns are in the falling state, the top surfaces of the four electromagnetic columns are flush with the bottom surface of the self-limiting groove; when the four electromagnetic columns are in the rising state, the four electromagnetic columns eject the substrate from the self-limiting groove.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. Preparation method of the present invention: In the self-positioning step, gravity is utilized to make the substrate automatically fall to the bottom of the groove to achieve initial positioning; in the adsorption step, negative pressure generated by the vacuum adsorption system is used to firmly adsorb the substrate on the bottom of the groove; in the coating step, a wet film is coated on the surface of the substrate by a coating mechanism, and the waste liquid is discharged through the diversion groove and the waste liquid diversion hole; in the annealing step, the wet film is subjected to in-situ annealing treatment by a heating module to promote the crystallization of the perovskite thin film into a film. In this way, through the coordinated operation of the self-positioning, adsorption, coating, and annealing steps, each link is closely coordinated, ensuring the accuracy and stability of the substrate positioning, avoiding the displacement of the substrate during the coating process; the waste liquid discharge design ensures a clean coating environment and reduces pollution; the in-situ annealing treatment can promptly process the wet film, which is beneficial to the formation of high-quality perovskite thin films, improving the preparation efficiency and yield of the thin films.

[0026] 2. Preparation system of the present invention: Through the design of the self-positioning groove, automatic positioning and rapid placement of the substrate are achieved, improving the operation efficiency. There is no need to manually adjust the position of the coating head and the substrate, increasing the production efficiency and improving the coating yield. The design of the waste liquid diversion groove and the waste liquid diversion hole ensures that the waste liquid can be quickly discharged, preventing the waste liquid from staying on the surface of the substrate and affecting the coating quality. The vacuum adsorption system provides uniform adsorption force to ensure the substrate remains stable during the coating process, improving the coating uniformity and consistency, and is suitable for large-area continuous preparation production. The present invention performs in-situ annealing treatment on the wet film through a heating module, without transferring the wet film, saving equipment investment and floor area. The in-situ annealing reduces mechanical damage during the wet film transfer process, and can significantly improve the efficiency and quality of thin film preparation, especially suitable for fields with extremely high requirements for process consistency (such as perovskite solar cells, OLED displays). Description of the Drawings

[0027] Figure 1 It is a schematic flow chart of the preparation method of the present invention;

[0028] Figure 2 It is a schematic flow chart of another embodiment of the preparation method of the present invention;

[0029] Figure 3 It is a top view structural schematic diagram of the coating stage of the present invention;

[0030] Figure 4 It is a front view structural schematic diagram of the coating stage of the present invention;

[0031] Figure 5 It is a top view structural schematic diagram of the coating stage of the present invention;

[0032] Figure 6 It is a front view structural schematic diagram of the coating stage of the present invention;

[0033] Figure 7Schematic side view structure of the coating stage of the present invention;

[0034] Figure 8 Schematic top view structure of the coating device of the present invention;

[0035] Figure 9 Schematic front view structure of the coating device of the present invention;

[0036] Figure 10 Schematic side view structure of the coating device of the present invention.

[0037] In the figure: 1. Substrate carrying platform; 2. Self-limiting groove; 3. Electromagnetic column; 4. Vacuum adsorption hole; 5. Waste liquid diversion groove; 6. Waste liquid diversion hole; 7. Vacuum adsorption chamber; 8. Heating module; 9. Vacuum extraction hole; 10. Counterweight base; 11. Vertical displacement manual control knob; 12. Horizontal displacement manual control knob; 13. Connecting mechanism; 14. Slide block; 15. Slide rail; 15a. Inverted trapezoidal slide rail track; 15b. Rectangular slide rail track; 16. Coating head; 17. Liquid injection hole; 18. Micro digital display head. Detailed implementation manners

[0038] Next, in combination with the accompanying drawings and specific implementation manners, the invention will be further described. It should be noted that, on the premise of no conflict, the following-described embodiments or technical features can be arbitrarily combined to form new embodiments. Except as otherwise specifically stated, the materials and equipment used in this embodiment can be purchased from the market. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application.

[0039] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application. In the description of the present application, the meaning of "a plurality" is two or more, unless otherwise specifically and precisely defined.

[0040] In the description of the present application, it should be noted that, unless otherwise clearly specified and defined, the terms "connected", "communicated", and "connected" should be understood in a broad sense. For example, it can be a direct connection, or it can be connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0041] In the description and claims of the present application, and in the above-mentioned drawings, the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0042] Please refer to Figure 1 , this embodiment provides a method for preparing a perovskite thin film, including:

[0043] S10. Self-limiting step: Place the substrate into the self-limiting groove on the substrate carrier platform, and the substrate is automatically positioned and attached to the bottom of the self-limiting groove under the action of gravity;

[0044] S20. Adsorption step: Firmly adsorb the substrate to the bottom of the self-limiting groove through a vacuum adsorption system;

[0045] S30. Coating step: Perform wet film coating on the upper surface of the substrate through a coating mechanism, and the waste liquid generated during the coating process is discharged to the waste liquid collection system through the waste liquid diversion groove and waste liquid diversion hole on the substrate carrier platform;

[0046] S40. Annealing step: After the coating is completed, perform in-situ annealing treatment on the wet film through a heating module.

[0047] Based on the above solution, in the self - positioning step of the present invention, gravity is utilized to make the substrate automatically fall to the bottom of the groove to achieve initial positioning; in the adsorption step, the negative pressure generated by the vacuum adsorption system is used to firmly adsorb the substrate on the bottom of the groove; in the coating step, a wet film is coated on the surface of the substrate by a coating mechanism, and the waste liquid is discharged through the diversion groove and the waste liquid diversion hole; in the annealing step, the heating module is used to perform in - situ annealing on the wet film to promote the crystallization of the perovskite film. Thus, through the coordinated operation of the self - positioning, adsorption, coating, and annealing steps, each link is closely coordinated, ensuring the accuracy and stability of the substrate positioning, avoiding the displacement of the substrate during the coating process; the waste liquid discharge design ensures a clean coating environment and reduces pollution; the in - situ annealing treatment can promptly process the wet film, which is beneficial to the formation of a high - quality perovskite film, improving the film preparation efficiency and the yield rate.

[0048] In a preferred embodiment of the present invention, in S10, the self - positioning step, the length - width dimension of the self - positioning groove is 0.5 - 1 mm larger than the corresponding dimension of the substrate, and a chamfer with a radius of 0.2 - 0.5 mm is provided at the edge. The chamfer design at the edge of the self - positioning groove reduces the frictional resistance and the risk of collision damage when the substrate is placed, enabling the substrate to be more smoothly self - positioned and fitted to the bottom of the groove under the action of gravity; the slight difference (0.5 - 1 mm) between the size of the self - positioning groove and the substrate ensures a gap of 0.25 - 0.5 mm between the edge of the substrate and the side wall of the groove, providing a fine - tuning space and preventing the substrate from shaking.

[0049] In a preferred embodiment of the present invention, in S20, the adsorption step, the vacuum pressure is controlled to be (-60)-(-80) kPa. Within this pressure range, a suitable pressure difference is formed between the vacuum adsorption chamber and the outside world, which can generate sufficient adsorption force to firmly adsorb the substrate on the bottom of the self - positioning groove. Precise control of the vacuum pressure ensures that the substrate remains stable during subsequent processes such as coating and annealing, and will not be displaced or loosened due to external forces (such as vibrations generated by the movement of the coating mechanism), guaranteeing the stability and consistency of the film preparation process and improving the product quality.

[0050] In a preferred embodiment of the present invention, in S30, the coating step, the coating speed is 8 - 20 mm / s. This speed range can make the coating liquid spread evenly on the surface of the substrate, avoiding problems such as uneven coating and flow marks caused by too fast speed, and also preventing the accumulation of the coating liquid and uneven drying caused by too slow speed. A reasonable coating speed ensures a uniform wet film thickness and a flat surface, which is beneficial to the uniform crystallization of the film during the subsequent annealing process, improving the optical and electrical properties of the perovskite film and enhancing the film quality.

[0051] In a preferred embodiment of the present invention, in S40, the annealing step, in-situ annealing treatment is performed at 80°C - 300°C, and the annealing time is 30 seconds - 60 minutes. Under these temperature and time conditions, the solvent in the wet film volatilizes, and the perovskite material undergoes a chemical reaction and crystallizes into a film. The reasonable setting of the temperature and time provides suitable thermodynamic conditions for the crystallization of the perovskite material. The appropriate annealing temperature and time promote the full crystallization of the perovskite thin film, forming a dense and uniform crystal structure, improving the stability and photoelectric conversion efficiency of the thin film, and ensuring the performance and quality of the perovskite thin film.

[0052] In a preferred embodiment of the present invention, in S40, the annealing step, the heating module adopts a heat conduction, heat radiation or microwave heating method.

[0053] Please refer to Figure 2 , and it further includes S50, the ejection step: after completing the annealing step, first turn off the vacuum adsorption system, and then activate the electromagnetic columns located at the four corners of the self-limiting groove to lift the substrate, wherein the electromagnetic columns are configured to have their top surfaces flush with the bottom surface of the groove in the lowered state and to eject the substrate in the raised state. The ejection step facilitates the removal of the substrate and avoids damage to the substrate or destruction of the thin film that may be caused by manual substrate removal.

[0054] Embodiment 1

[0055] This embodiment provides a method for preparing a perovskite thin film, including:

[0056] S10, the self-limiting step: placing the substrate into the self-limiting groove on the substrate carrying platform, and the substrate automatically positions and fits against the bottom of the self-limiting groove under the action of gravity;

[0057] S20, the adsorption step: firmly adsorbing the substrate against the bottom of the self-limiting groove through a vacuum adsorption system; controlling the vacuum pressure to be -70 kPa;

[0058] S30, the coating step: wet-coating the upper surface of the substrate through a coating mechanism, and the waste liquid generated during the coating process is discharged to the waste liquid collection system through the waste liquid diversion groove and waste liquid diversion holes on the substrate carrying platform; the coating speed is 12 mm / s;

[0059] S40, the annealing step: after coating is completed, in-situ annealing treatment is performed on the wet film through a heating module. The annealing temperature is 150°C, and the annealing time is 20 minutes;

[0060] S50, the ejection step: after completing the annealing step, first turn off the vacuum adsorption system, and then activate the electromagnetic columns located at the four corners of the self-limiting groove to lift the substrate, wherein the electromagnetic columns are configured to have their top surfaces flush with the bottom surface of the groove in the lowered state and to eject the substrate in the raised state.

[0061] Based on the above Embodiment 1, the effects of different coating speeds and annealing temperatures on the performance of perovskite thin films were further explored. During this process, different coating speeds and annealing temperatures were set, while other conditions remained the same as in Embodiment 1. For the specific performance of the perovskite thin films, see Table 1.

[0062] Table 1

[0063]

[0064]

[0065] As can be seen from Table 1, when the coating speed is 12 mm / s + the annealing temperature is 150 °C, the grain size is moderate (700 - 900 nm), and the film uniformity and continuity are better.

[0066] From Figure 3 it can be seen that when the coating speed is 8 mm / s + the annealing temperature is 100 °C, the film characteristics are: fish scale pattern, porous.

[0067] From Figure 4 it can be seen that when the coating speed is 12 mm / s + the annealing temperature is 150 °C, the film characteristics are: uniform and continuous, dense.

[0068] Embodiment 2

[0069] Please refer to Figures 5 - 10 as shown. This embodiment provides a preparation system for implementing the preparation method of the perovskite thin film in Embodiment 1, including:

[0070] A coating device, which includes a counterweight base 10, a coating stage, and a coating mechanism;

[0071] The coating stage is installed on the counterweight base 10; the coating stage includes a substrate bearing platform 1 and a heating module 8; a self-limiting groove 2 is provided on the upper surface of the substrate bearing platform 1; a waste liquid diversion groove 5 is provided in the self-limiting groove 2, and a waste liquid diversion hole 6 communicating with the waste liquid diversion groove 5 is provided inside the substrate bearing platform 1; a vacuum adsorption chamber 7 is formed inside the substrate bearing platform 1 and is located below the self-limiting groove 2; a plurality of vacuum adsorption holes 4 are provided in the self-limiting groove 2, and the plurality of vacuum adsorption holes 4 communicate with the vacuum adsorption chamber 7 respectively; a vacuum extraction hole 9 communicating with the vacuum adsorption chamber 7 is provided on the substrate bearing platform 1; the heating module 8 is provided below the vacuum adsorption chamber 7 or at the bottom of the coating stage; the coating mechanism is installed on the counterweight base 10 and is located above the substrate bearing platform 1;

[0072] A vacuum adsorption system, which is connected to the vacuum adsorption chamber 7; specifically, the vacuum adsorption system includes a vacuum pump and a vacuum adsorption pipeline.

[0073] Waste liquid collection system, the liquid inlet end of the waste liquid collection system is connected to the liquid discharge port of the waste liquid diversion hole 6. Specifically, the waste liquid collection system includes a waste liquid collection container and a waste liquid conveying pipeline.

[0074] The length and width of the self-limiting groove 2 are greater than the corresponding dimensions of the substrate, and the depth is less than or equal to the thickness of the substrate;

[0075] On the basis of the above structure, during the working process, first use a transfer device or a robotic arm to gently place the substrate into the self-limiting groove 2. Under the action of gravity, the substrate automatically positions and fits on the bottom of the self-limiting groove 2. Start the vacuum pumping device, and pump air into the vacuum adsorption chamber 7 through the vacuum pumping hole 9 to create a negative pressure environment in the vacuum adsorption chamber 7. At this time, the vacuum adsorption holes 4 in the self-limiting groove 2 generate suction force, firmly adsorbing the substrate on the bottom of the self-limiting groove 2. In the state where the substrate is firmly fixed, the coating operation is carried out. The waste liquid generated during the coating process is discharged to the external waste liquid collection system through the waste liquid diversion groove 5 and the waste liquid diversion hole 6. After the coating is completed, the wet film is subjected to in-situ annealing treatment through the heating module 8. After the annealing operation is completed, the vacuum pumping device is turned off to release the vacuum adsorption state. At this time, the substrate can be easily taken out from the self-limiting groove 2. Through the design of the self-limiting groove 2 of the present invention, automatic positioning and rapid placement of the substrate are realized, improving the operation efficiency. The design of the waste liquid diversion groove 5 and the waste liquid diversion hole 6 ensures that the waste liquid can be quickly discharged, avoiding the retention of the waste liquid on the surface of the substrate and affecting the coating quality. The vacuum adsorption system provides uniform adsorption force to ensure that the substrate remains stable during the coating process, improving the coating uniformity and consistency.

[0076] It should be noted that the substrate carrier platform 1 is a good conductor of heat such as metal or ceramic.

[0077] In a preferred embodiment of the present invention, the number of the waste liquid diversion grooves 5 is two, and they are symmetrically distributed on the opposite sides of the self-limiting groove 2 along the long axis direction of the substrate; the number of the waste liquid diversion holes 6 is two, and they are respectively in one-to-one correspondence and communication with the two waste liquid diversion grooves 5. In this way, the double-diversion groove design ensures that the overflowing coating liquid is exported synchronously from both sides, reducing the liquid film residue and reducing or avoiding the pollution of the self-limiting groove 2.

[0078] In a preferred embodiment of the present invention, the width of the waste liquid diversion groove 5 is 1-3 mm, the depth is 0.5-1.5 mm, and the bottom of the groove is inclined downward at 2°-6° to promote the flow of the waste liquid; the waste liquid diversion hole 6 is inclined downward at 10°-20° to avoid the backflow of the waste liquid.

[0079] In a preferred embodiment of the present invention, the edges of the self-limiting groove 2 are chamfered. This chamfered design of the edges of the self-limiting groove 2 reduces the frictional resistance and the risk of collision damage when the substrate is inserted, enabling the substrate to be more smoothly self-positioned under the action of gravity and fit snugly against the bottom of the groove. The difference in length between the self-limiting groove 2 and the substrate is 0.5 - 1 mm, and the difference in width between the self-limiting groove 2 and the substrate is 0.5 - 1 mm. This slight difference (0.5 - 1 mm) in the dimensions between the self-limiting groove 2 and the substrate ensures a gap of 0.25 - 0.5 mm between the edge of the substrate and the side wall of the groove, providing a fine-tuning space while preventing the substrate from wobbling.

[0080] In a preferred embodiment of the present invention, there are also four electromagnetic columns 3. The four electromagnetic columns 3 are respectively arranged on the substrate carrier platform 1 and located at the four corners of the self-limiting groove 2. The four electromagnetic columns 3 are configured to be controlled by an electromagnetic system to switch between a raised state and a lowered state. When the four electromagnetic columns 3 are in the lowered state, the top surfaces of the four electromagnetic columns 3 are flush with the bottom surface of the self-limiting groove 2. When the four electromagnetic columns 3 are in the raised state, the four electromagnetic columns 3 eject the substrate from the self-limiting groove 2.

[0081] In this way, the electromagnetic columns 3 achieve the up / down switching through the electromagnetic system, reducing manual operation and improving production efficiency. At the same time, they have the advantages of simple structure and small occupied space. When in the lowered state, the top surface of the column is flush with the bottom surface of the groove, avoiding scratching the substrate. When in the raised state, it ejects the substrate, facilitating the taking of the substrate.

[0082] In a preferred embodiment of the present invention, the counterweight base 10 can be made of stone, such as marble, or metal, such as stainless steel, or a composite structure of both, without specific limitation, to ensure the stability of the equipment device during operation. Integrating the coating stage and the coating mechanism onto the counterweight base 10 reduces the floor area occupied by the equipment and improves the system stability.

[0083] In a preferred embodiment of the present invention, the coating mechanism includes a three-axis displacement device and a coating head 16. The three-axis displacement device enables the coating head 16 to move in the up / down direction, front / back direction, or left / right direction through manual or digital control. In this way, the three-axis displacement device supports manual / digital control to achieve precise movement of the coating head 16 in three-dimensional space.

[0084] Among them, the driving method of the displacement can be any one of a guide rail, a lead screw, a hinge, a belt, etc., without specific limitation. The front / back direction is along the slide rail 15, the up / down direction is along the longitudinal movement of the slider 14, and the left / right direction is along the transverse movement of the connecting member.

[0085] Further, there are slide rails 15 arranged along the coating direction, installed on both sides of the upper surface of the counterweight base 10. The two slide rails 15 are parallel to each other, and the parallel spacing is greater than or equal to the width of the coating stage. The slider 14 is installed on the slide rail 15. Further, the slide rail 15 has an inverted trapezoidal structure design, including an inverted trapezoidal slide rail track 15a and a rectangular slide rail track 15b, making the combination of the slide rail 15 and the slider 14 more tightly and firmly connected, not easily shaken, and ensuring the running stability.

[0086] Further, a vertical displacement manual adjustment knob 11 is installed on the side of the slider 14 for vertical movement. The knobs on both sides of the slider 14 can respectively fine-tune the left and right positions; a horizontal displacement manual adjustment knob 12 is installed on the upper end of the slider 14 for horizontal movement, and both the left and right knobs can independently achieve horizontal displacement. The horizontal movement depends on the connection mechanism 13, and the connection mechanism 13 is used to connect the slider 14 and the coating head 16.

[0087] In a preferred embodiment of the present invention, the coating mechanism further includes:

[0088] A differential digital display head 18 provided on the three-axis displacement device for real-time monitoring of the distance between the coating head 16 and the substrate to ensure the consistency of the coating thickness; preferably, the differential digital display head 18 is installed above or on the side of the connecting piece for intuitively displaying the distance between the coating head 16 and the substrate; the differential digital display head 18 has a zeroing function, and the numerical display can be positive or negative.

[0089] A foreign object detection and protection system provided on the three-axis displacement device, configured to automatically stop and lock when a foreign object is detected to protect the coating device and avoid equipment damage or substrate scrapping.

[0090] In a preferred embodiment of the present invention, the coating head 16 is installed on the connection mechanism 13 and connected to the three-axis displacement device, enabling the coating head 16 to move up and down, left and right, and front and back, continuously adjustable. The width of the coating head 16 is adjustable according to the size of the substrate, and the wet film coating is realized by moving along the direction of the slide rail 15.

[0091] Further, a liquid injection hole 17 is provided on the coating head 16. Specifically, the liquid injection hole 17 is connected to an external liquid injection system, and the external liquid injection system can be manually controlled or controlled by a digital circuit.

[0092] In a preferred embodiment of the present invention, the thin film preparation system may further include an external liquid injection system and a precursor solution preparation to form a complete thin film production system (such as a perovskite thin film production system).

[0093] Although only certain components and embodiments of the present application have been illustrated and described, many modifications and changes can be conceived by those skilled in the art without actually departing from the scope and spirit of the claims, such as changes in the size, dimensions, structure, shape and proportion, mounting arrangement, material use, color, orientation, etc. of the respective elements.

[0094] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A method for preparing a perovskite thin film, characterized in that, Including: S10, self - limiting step: Place the substrate into the self - limiting groove on the substrate carrying platform. Under the action of gravity, the substrate is automatically positioned and fits against the bottom of the self - limiting groove. S20, adsorption step: Firmly adsorb the substrate on the bottom of the self - limiting groove through a vacuum adsorption system. S30, coating step: Wet - film coat the upper surface of the substrate through a coating mechanism. The waste liquid generated during the coating process is discharged to the waste - liquid collection system through the waste - liquid diversion groove and waste - liquid diversion holes on the substrate carrying platform. S40, annealing step: After coating, perform in - situ annealing treatment on the wet film through a heating module.

2. The preparation method of the perovskite thin film according to claim 1, characterized in that, In S10, the self - limiting step, the length and width dimensions of the self - limiting groove are 0.5 - 1 mm larger than the corresponding dimensions of the substrate, and the edges are provided with chamfers with a radius of 0.2 - 0.5 mm.

3. The preparation method of the perovskite thin film according to claim 1, characterized in that, In S20, the adsorption step, control the vacuum pressure to be (-60)-(-80) kPa.

4. The method for preparing the perovskite thin film according to claim 1, wherein In S30, the coating step, the coating speed is 8 - 20 mm / s.

5. The method for preparing the perovskite thin film according to claim 1, wherein In S40, the annealing step, perform in - situ annealing treatment at 80℃ - 300℃, and the annealing time is 0.5 - 60 minutes.

6. The method for preparing a perovskite thin film according to claim 5, wherein In S40, the annealing step, the heating module adopts a heat - conduction, heat - radiation or microwave heating method.

7. The method for preparing a perovskite thin film according to claim 1, characterized in that, It also includes S50, ejection step: After the annealing step is completed, first turn off the vacuum adsorption system, and then activate the electromagnetic columns located at the four corners of the self - limiting groove to lift the substrate, where the electromagnetic columns are configured to have their top surfaces flush with the bottom surface of the groove in the descending state and eject the substrate in the ascending state.

8. A preparation system for perovskite thin films, characterized in that, Including: A coating device, which includes a weight base, a coating stage, and a coating mechanism. The coating stage is installed on the weight base; the coating stage includes a substrate carrying platform and a heating module; the upper surface of the substrate carrying platform is provided with a self - limiting groove; a waste - liquid diversion groove is arranged in the self - limiting groove, and waste - liquid diversion holes communicating with the waste - liquid diversion groove are formed inside the substrate carrying platform; a vacuum adsorption chamber located below the self - limiting groove is formed inside the substrate carrying platform; a plurality of vacuum adsorption holes are arranged in the self - limiting groove, and the plurality of vacuum adsorption holes communicate with the vacuum adsorption chamber respectively; a vacuum extraction hole communicating with the vacuum adsorption chamber is arranged on the substrate carrying platform; the heating module is arranged below the vacuum adsorption chamber or at the bottom of the coating stage; the coating mechanism is installed on the weight base and is located above the substrate carrying platform. A vacuum adsorption system, which is connected to the vacuum adsorption chamber. A waste - liquid collection system, the liquid inlet end of which is connected to the drain port of the waste - liquid diversion hole.

9. The preparation system of the perovskite thin film according to claim 8, characterized in that, The number of the waste - liquid diversion grooves is two, and they are symmetrically distributed on the opposite sides of the self - limiting groove along the long axis direction of the substrate; the number of the waste - liquid diversion holes is two, and they are respectively in one - to - one correspondence and communication with the two waste - liquid diversion grooves; the width of the waste - liquid diversion groove is 1 - 3 mm, the depth is 0.5 - 1.5 mm, and the bottom of the groove is inclined downward at 2° - 6°; the waste - liquid diversion holes are inclined downward at 10° - 20°.

10. The preparation system of the perovskite thin film according to claim 9, wherein, It further includes four electromagnetic columns, and the four electromagnetic columns are respectively arranged on the substrate carrying platform and located at the four corners of the self-limiting groove. The four electromagnetic columns are configured to be controlled by an electromagnetic system to switch between a raised state and a lowered state; when the four electromagnetic columns are in the lowered state, the top surfaces of the four electromagnetic columns are flush with the bottom surface of the self-limiting groove; when the four electromagnetic columns are in the raised state, the four electromagnetic columns eject the substrate from the self-limiting groove.

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