A flash evaporation apparatus and method

Abstract

The application discloses a flash evaporation device and a flash evaporation method. The chamber is divided into at least two sub-chambers by setting valves in the chamber. The sub-chambers are connected to form a larger chamber when the valves are opened. The sub-chambers are isolated from each other when the valves are closed. The pumping rates of the gas pumps connected to different sub-chambers can be different. In the initial stage of flash evaporation, the valves are opened, and the gas pump with a smaller pumping rate is started, so that the film to be flash evaporated can be pumped at a smaller pumping rate in the larger chamber, thereby avoiding the problem that a great gas disturbance is generated to cause the prepared film to be non-uniform. When the air pressure in the chamber reaches a preset air pressure, the valves and the gas pump with a smaller pumping rate are closed, and the gas pump with a larger pumping rate is started, so that the film to be flash evaporated can be quickly flash evaporated in the smaller sub-chamber. In this stage, the gas amount in the sub-chamber is small, and therefore, the quick vacuum pumping has a smaller influence on the uniformity of the obtained film.

Description

Technical Field

[0001] This invention relates to the field of flash evaporation, and particularly to a flash evaporation apparatus and flash evaporation method. Background Technology

[0002] Perovskite thin-film solar cells are the third generation of solar cells that have been developed in the last decade. Their film structure and conventional preparation method are as follows: a transparent conductive layer, a first carrier transport layer, a perovskite layer, a second carrier transport layer, and a metal layer are sequentially prepared on a glass substrate. The transparent conductive layer and the metal layer serve as electrode layers, and the metal layer can also be a transparent conductive layer. The perovskite layer serves as a light absorption layer.

[0003] Flash evaporation is a common process for preparing large-area perovskite layers. Specifically, a perovskite precursor solution is first prepared and spin-coated onto a substrate to form a wet perovskite film. The substrate covered with the wet perovskite film is then placed in a flash evaporation chamber and rapidly evacuated to remove the solvent, yielding a perovskite mesophase film. The flash evaporation process requires evacuation to below 10 Pa within seconds to tens of seconds to obtain a high-quality perovskite film. However, at the beginning of flash evaporation, the chamber is at atmospheric pressure with a large amount of gas. Excessive evaporation speed can cause significant gas disturbance, scavenging the film surface and resulting in uneven flash evaporation. To avoid uneven vacuum evaporation speed within the flash chamber, a sufficiently large flash evaporation chamber relative to the film to be flashed is required. However, a larger flash evaporation chamber leads to a slower evaporation speed, making it impossible to obtain a high-quality perovskite film.

[0004] Therefore, how to achieve the required gas pressure in the chamber where the film to be flashed is located within a short time, and to ensure uniform pumping speed throughout the process, thereby preparing a uniform perovskite film, is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a flash evaporation apparatus and flash evaporation method to bring the gas pressure in the chamber where the film to be flashed is located to the gas pressure required for the flash evaporation process in a short time, and to achieve uniform pumping speed throughout the process, thereby preparing a uniform perovskite film.

[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0007] A flash evaporation device, the flash evaporation device comprising:

[0008] The chamber includes at least two sub-chambers, the at least two sub-chambers including a first sub-chamber and a second sub-chamber located on one side of the first sub-chamber, the first sub-chamber being used to place the film to be flash-evaporated;

[0009] A first valve is provided between the first sub-chamber and the second sub-chamber. When the first valve is opened, the first sub-chamber and the second sub-chamber are connected. When the first valve is closed, the first sub-chamber and the second sub-chamber are isolated.

[0010] The first sub-chamber is connected to a first air pump, and the second sub-chamber is connected to a second air pump. The air pumping rate of the first air pump is greater than that of the second air pump.

[0011] Optionally, the at least two sub-chambers further include a third sub-chamber, the third sub-chamber and the second sub-chamber being located on opposite sides of the first sub-chamber;

[0012] A second valve is provided between the first sub-chamber and the third sub-chamber. When the second valve is open, the first sub-chamber and the third sub-chamber are connected. When the second valve is closed, the first sub-chamber and the third sub-chamber are isolated.

[0013] The third sub-chamber is connected to a third air pump, and the air pumping rate of the first air pump is greater than that of the third air pump.

[0014] Optionally, the pumping rate of the second pump is equal to the pumping rate of the third pump.

[0015] Optionally, the flash evaporation device further includes a first vacuum gauge and a second vacuum gauge;

[0016] The first vacuum gauge is connected to the first sub-chamber and is used to detect the air pressure inside the first sub-chamber;

[0017] The second vacuum gauge is connected to the second sub-chamber and is used to detect the air pressure inside the second sub-chamber.

[0018] Optionally, the flash evaporation device further includes a first regulating valve and a second regulating valve;

[0019] The first regulating valve is located on the connection passage between the first sub-chamber and the first air pump. When the first regulating valve is open, the first sub-chamber and the first air pump are connected. When the first regulating valve is closed, the first sub-chamber and the first air pump are isolated.

[0020] The second regulating valve is located on the connection passage between the second sub-chamber and the second air pump. When the second regulating valve is open, the second sub-chamber and the second air pump are connected. When the second regulating valve is closed, the second sub-chamber and the second air pump are isolated.

[0021] Optionally, the flash evaporation device further includes a first gas filling line and a second gas filling line;

[0022] The first inflation line is provided with a first inflation valve. When the first inflation valve is opened, the first inflation line is connected to the first sub-chamber. When the first inflation valve is closed, the first inflation line is isolated from the first sub-chamber.

[0023] A second inflation valve is provided on the second inflation pipeline. When the second inflation valve is opened, the second inflation pipeline is connected to the second sub-chamber. When the second inflation valve is closed, the second inflation pipeline is isolated from the second sub-chamber.

[0024] Optionally, the flash evaporation device may also include a control system;

[0025] The control system is used to, when flash evaporating the film to be flashed, first open the first valve to connect the first sub-chamber and the second sub-chamber, and start the second vacuum pump to extract air. After the air pressure in the connected first sub-chamber and the second sub-chamber reaches the preset air pressure, the first valve is closed to isolate the first sub-chamber and the second sub-chamber, and the second vacuum pump is turned off and the first vacuum pump is turned on to extract air.

[0026] A flash evaporation method, applied to the flash evaporation apparatus described in any one of the above claims, the flash evaporation method comprising:

[0027] Open the first valve to connect the first sub-chamber and the second sub-chamber, and start the second air pump to extract air;

[0028] Once the air pressure in the first and second sub-chambers reaches the preset air pressure, the first valve is closed to isolate the first and second sub-chambers, and the second air pump is turned off while the first air pump is turned on to pump air.

[0029] Optionally, in the flash evaporation device, the at least two sub-chambers further include a third sub-chamber, the third sub-chamber and the second sub-chamber are located on opposite sides of the first sub-chamber, a second valve is provided between the first sub-chamber and the third sub-chamber, and the third sub-chamber is connected to a third air pump, the air pumping rate of the first air pump is greater than the air pumping rate of the third air pump.

[0030] The flash evaporation method further includes:

[0031] While opening the first valve, the second valve is opened to connect the first sub-chamber, the second sub-chamber, and the third sub-chamber. At the same time as the second air pump is started to pump air, the third air pump is started to pump air.

[0032] Once the air pressure in the first, second, and third sub-chambers reaches the preset air pressure, the second valve is closed while the first valve is closed, isolating the first, second, and third sub-chambers. At the same time, the third pump is turned off while the second pump is turned off, and the first pump is turned on to pump air.

[0033] Optionally, the relationship between the preset pressure value P1 and the saturated vapor pressure P0 of the solvent in the film to be flashed satisfies: P0≤P1≤P0+200pa, where the saturated vapor pressure P0 of the solvent is the pressure required for the liquid and vapor of the solvent to be in phase equilibrium under a closed environment and a preset temperature.

[0034] Compared with existing technologies, the above technical solution has the following advantages:

[0035] The flash evaporation device provided in this application divides the chamber into at least two sub-chambers by setting valves in the chamber, and the pumping speed of the pumps connected to the different sub-chambers can be different, so that the size of the chamber where the film to be flashed is located and the pumping speed can be controlled in different flash evaporation stages.

[0036] Specifically, the at least two sub-chambers include a first sub-chamber and a second sub-chamber. The first sub-chamber is used to hold the membrane to be flash-evaporated. A first valve is provided between the first and second sub-chambers, so that when the first valve is open, the first and second sub-chambers can be connected to form a larger chamber. When the first valve is closed, the first and second sub-chambers are isolated into two smaller chambers. Furthermore, the pumping speed of the first pump connected to the first sub-chamber is greater than the pumping speed of the second pump connected to the second sub-chamber. Therefore, when the first valve is open and the second pump is used for evacuation, a smaller pumping speed can be used in the larger chamber connected to the first and second sub-chambers. The gas is gradually reduced in the chamber containing the flash-evaporated film by a high pumping rate. This prevents large gas disturbances from purging the surface of the film, which could lead to uneven film preparation. Then, when the gas pressure in the connected first and second sub-chambers reaches the preset pressure (i.e., when the gas volume in the first sub-chamber is relatively small), the first valve is closed to isolate the first and second sub-chambers. The second pumping pump is then turned off, and the first pumping pump is turned on to pump the gas. At this time, pumping can be performed at a higher pumping rate only in the first sub-chamber, so that the chamber containing the flash-evaporated film is quickly pumped to the gas pressure required for the flash evaporation process, with minimal impact on the uniformity of the obtained film.

[0037] Therefore, the flash evaporation device provided in this application embodiment can bring the gas pressure in the first sub-chamber where the film to be flashed is located to the gas pressure required for the flash evaporation process in a short time, and the pumping speed is relatively uniform throughout the entire pumping process, thereby preparing a uniform perovskite film. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the structure of a flash evaporation device provided in an embodiment of this application;

[0040] Figure 2 This is a schematic flowchart of a flash evaporation method provided in an embodiment of this application;

[0041] Figure 3 This is a schematic flowchart of another flash evaporation method provided in an embodiment of this application. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Those skilled in the art can make similar extensions without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0044] Secondly, this application provides a detailed description in conjunction with schematic diagrams. When detailing the embodiments of this application, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not limit the scope of protection of this application. In addition, actual fabrication should include three-dimensional spatial dimensions of length, width, and depth.

[0045] As mentioned in the background section, how to achieve the required gas pressure in the chamber where the film to be flashed is located within a short time, and to ensure uniform pumping speed throughout the process, thereby preparing a uniform perovskite film, is a technical problem that urgently needs to be solved by those skilled in the art.

[0046] The inventors discovered that when preparing perovskite thin films using the existing flash evaporation process, in the initial stage of flash evaporation, due to the atmospheric pressure and large amount of gas in the flash chamber, excessive pumping speed can lead to an uneven pumping speed field within the flash chamber, resulting in significant gas disturbances and causing surface scavenging of the film, thus leading to uneven flash evaporation. In the later stage of flash evaporation, due to the small amount of gas in the chamber, rapid vacuuming has a smaller impact on the uniformity of the film.

[0047] To avoid the problem of uneven vacuum pumping speed field in the flash chamber during the initial stage of flash evaporation, a flash chamber that is large enough relative to the film to be flashed needs to be set. However, a larger flash chamber will result in a slower pumping speed in the later stage of flash evaporation, making it impossible to obtain high-quality perovskite films and causing very high energy consumption.

[0048] Based on the above research, this application provides a flash evaporation device and flash evaporation method to bring the gas pressure in the chamber where the film to be flashed is located to the gas pressure required for the flash evaporation process in a short time, and to ensure uniform pumping speed throughout the flash evaporation process, thereby preparing a uniform perovskite film.

[0049] The flash evaporation device provided in this application divides the chamber into at least two sub-chambers by setting valves in the chamber, and the pumping speed of the pumps connected to the different sub-chambers can be different, so that the size of the chamber where the film to be flashed is located and the pumping speed can be controlled in different flash evaporation stages.

[0050] Specifically, the at least two sub-chambers include a first sub-chamber and a second sub-chamber. The first sub-chamber is used to place the membrane to be flashed. A first valve is provided between the first and second sub-chambers, so that when the first valve is open, the first and second sub-chambers can be connected to form a larger chamber. When the first valve is closed, the first and second sub-chambers are isolated into two smaller chambers. Furthermore, the pumping rate of the first pump connected to the first sub-chamber is greater than the pumping rate of the second pump connected to the second sub-chamber, thereby employing a two-step flash evaporation method.

[0051] In the initial stage of flash evaporation, when the first valve is opened and the second pump is used for evacuation, evacuation can be carried out at a lower rate in the larger chamber connecting the first and second sub-chambers. This allows the gas in the chamber containing the film to be flashed to decrease slowly, avoiding large gas disturbances that could purge the surface of the film and cause unevenness in the prepared film. Then, in the later stage of flash evaporation, when the gas pressure in the connected first and second sub-chambers reaches the preset pressure (i.e., when the amount of gas in the first sub-chamber is relatively small), the first valve is closed to isolate the first and second sub-chambers. The second pump is then turned off, and the first pump is turned on for evacuation. At this time, evacuation can be carried out at a higher rate only in the first sub-chamber, allowing the first sub-chamber containing the film to be flashed to be quickly evacuated to the gas pressure required for the flash evaporation process, with minimal impact on the uniformity of the obtained film.

[0052] Therefore, it can be seen that the flash evaporation apparatus provided in this application embodiment can, in the later stage of flash evaporation, bring the gas pressure in the first sub-chamber where the film to be flashed is located to the gas pressure required by the flash evaporation process in a short time, and the pumping speed is uniform throughout the flash evaporation process, thereby producing a uniform perovskite film.

[0053] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] Figure 1 An embodiment of this application provides a flash evaporation apparatus, such as... Figure 1 As shown, the flash evaporation device includes:

[0055] The chamber 10 includes at least two sub-chambers, the at least two sub-chambers including a first sub-chamber 11 and a second sub-chamber 12 located on one side of the first sub-chamber 11, the first sub-chamber 11 being used to place the film to be flashed;

[0056] A first valve 21 is provided between the first sub-chamber 11 and the second sub-chamber 12. When the first valve 21 is opened, the first sub-chamber 11 and the second sub-chamber 12 are connected. When the first valve 21 is closed, the first sub-chamber 11 and the second sub-chamber 12 are isolated.

[0057] The first sub-chamber 11 is connected to a first air pump 31, and the second sub-chamber 12 is connected to a second air pump 32. The air pumping rate of the first air pump 31 is greater than that of the second air pump 32.

[0058] Optionally, the first pump 31 can be a cold pump or a molecular pump.

[0059] Optionally, the second air pump 32 can be a mechanical pump.

[0060] Specifically, in the actual flash evaporation process, at the initial stage of flash evaporation, the film to be flashed is transferred to the first sub-chamber 11. At the same time as the first valve 21 is opened, the second vacuum pump 32 is started to pump air, so that the film to be flashed can be pumped at a small pumping rate in the larger chamber that connects the first sub-chamber 11 and the second sub-chamber 12. This causes the gas in the chamber where the film to be flashed is located to decrease slowly, avoiding the problem of huge gas disturbance caused by the rapid flow of a large amount of gas in the chamber, which would blow away the film surface and result in an uneven film.

[0061] In the later stage of flash evaporation, when the gas pressure in the connected first sub-chamber 11 and second sub-chamber 12 reaches the preset gas pressure, the first valve 21 and the second vacuum pump 32 are closed, and the first vacuum pump 31 is turned on at the same time. This allows the film to be flashed to be evaporated in the smaller first sub-chamber 11 at a larger vacuum rate, thereby achieving the purpose of flash evaporation. Since the amount of gas in the first sub-chamber 11 is small in this flash evaporation stage, the rapid vacuuming has little impact on the uniformity of the obtained film.

[0062] Therefore, the flash evaporation apparatus provided in this application embodiment can bring the gas pressure in the first sub-chamber 11 where the film to be flashed is located to the gas pressure required for the flash evaporation process in a short time, and the gas pumping speed is uniform throughout the flash evaporation process, thereby producing a uniform film.

[0063] As can be seen from the above embodiments, in order to obtain a uniform film, the pumping speed should be uniform throughout the flash evaporation process. Specifically, in the initial stage of flash evaporation, since the chamber 10 is under atmospheric pressure and the gas volume is relatively large, uneven pumping speed can easily cause scavenging of the film surface, resulting in an uneven film. In the later stage of flash evaporation, the gas volume is relatively small, and the impact on the uniformity of the obtained film is relatively small.

[0064] Furthermore, considering that during the initial stage of flash evaporation, the second pump 22, connected to the second sub-chamber 12, evacuates the entire chamber 10, causing the gas in the first sub-chamber 11, where the film to be flashed is located, to slowly flow towards the second sub-chamber 12. It is understandable that simultaneously evacuating from both sides of the first sub-chamber 11, where the film to be flashed is located, achieves a more uniform pumping speed than evacuating from only one side, thereby producing a uniform film.

[0065] Therefore, as Figure 1 As shown, optionally, the flash evaporation device provided in this application embodiment further includes a third sub-chamber 13 in the at least two sub-chambers, and the third sub-chamber 13 and the second sub-chamber 12 are located on opposite sides of the first sub-chamber 11;

[0066] A second valve 22 is provided between the first sub-chamber 11 and the third sub-chamber 13. When the second valve 22 is open, the first sub-chamber 11 and the third sub-chamber 13 are connected. When the second valve 22 is closed, the first sub-chamber 11 and the third sub-chamber 13 are isolated.

[0067] The third sub-chamber 13 is connected to a third air pump 33, and the air pumping rate of the first air pump 31 is greater than that of the third air pump 33.

[0068] Optionally, in this embodiment, the third air pump 33 can be a mechanical pump.

[0069] Specifically, in the actual flash evaporation process, in the initial stage of flash evaporation, the first valve 21 and the second valve 22 are opened, connecting the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13. The film to be flashed is located in the larger chamber. At the same time, the second pump 32 and the third pump 33 are turned on. Since the second sub-chamber 12, which is connected to the second pump 32, and the third sub-chamber 13, which is connected to the third pump 33, are symmetrical with respect to the first sub-chamber 11 where the film to be flashed is located, the pumping field of the first sub-chamber 11 where the film to be flashed is located is relatively uniform. Moreover, the pumping rates of the second pump 32 and the third pump 33 are relatively small. Therefore, in this flash evaporation stage, the film to be flashed can be pumped by a smaller and more uniform pumping field in the larger chamber, so that the gas in the first sub-chamber 11 where the film to be flashed is located decreases slowly and uniformly, avoiding the generation of huge gas disturbances that would purge the surface of the film to be flashed, resulting in an uneven film.

[0070] In the later stage of flash evaporation, when the gas pressure in the connected first sub-chamber 11, second sub-chamber 12, and third sub-chamber 13 reaches the preset gas pressure value, that is, when the amount of gas in the first sub-chamber 11 is relatively small, the first valve 21 and the second valve 22 are closed, so that the film to be flashed changes from being in a larger chamber to being in only the smaller first sub-chamber 11, and the flash evaporation space becomes smaller. At the same time, the second vacuum pump 32 and the third vacuum pump 33 are closed, and the first vacuum pump 31 with a larger pumping rate is turned on. Therefore, in this flash evaporation stage, the film to be flashed can be quickly flashed in the smaller first sub-chamber 11, thereby achieving the purpose of flash evaporation. Since the amount of gas in the first sub-chamber 11 is small in this flash evaporation stage, the rapid vacuuming has little impact on the uniformity of the obtained film.

[0071] As can be seen from the above embodiments, simultaneously evacuating both sides of the first sub-chamber 11 where the flash-evaporated film is located results in better uniformity of the prepared film. It is conceivable that if the evacuation field direction on both sides of the first sub-chamber 11 is symmetrical and of the same size, the evacuation speed in the first sub-chamber 11 where the flash-evaporated film is located will be more uniform, and the uniformity of the prepared film will be even better.

[0072] Therefore, optionally, the second sub-chamber 12 and the third sub-chamber 13 are respectively provided with a first air extraction port and a second air extraction port. The first air extraction port is connected to the first air extraction pump 31, and the second air extraction port is connected to the second air extraction pump 32. The first air extraction port and the second air extraction port are symmetrically arranged relative to the first sub-chamber 11, so that the air extraction field directions on both sides of the first sub-chamber 11 are symmetrical.

[0073] Optionally, the pumping rate of the second pump 32 is equal to the pumping rate of the third pump 33, so that the pumping fields on both sides of the first sub-chamber 11 are of the same size.

[0074] It should be noted that in the later stage of flash evaporation in any of the above embodiments, in order to achieve the purpose of flash evaporation in a shorter time, the preset gas pressure value should be as close as possible to the gas pressure value required by the flash evaporation process. Therefore, optionally, the relationship between the preset gas pressure value P1 and the saturated vapor pressure P0 of the solvent in the film to be flashed satisfies: P0≤P1≤P0+200pa, where the saturated vapor pressure P0 of the solvent is the pressure that the liquid and vapor of the solvent have in a phase equilibrium state under a closed environment and a preset temperature.

[0075] It is understandable that the size of the chamber containing the film to be flashed has a significant impact on the uniformity of the prepared film during different flash evaporation stages. Specifically, in the initial stage of flash evaporation, with the pumping rates of the second pump 32 and the third pump 33 remaining constant, the larger the chamber connecting the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, the smaller the rate at which the gas in the first sub-chamber 11 containing the film to be flashed decreases, and thus the better the uniformity of the prepared film. Therefore, optionally, along the first direction, the relationship between the length d1 of the film sample and the length d2 of the chamber 10 satisfies: d2 ≥ 2d1, and the first direction is parallel to the direction in which the first sub-chamber 11 and the second sub-chamber 12 are arranged.

[0076] In the later stage of flash evaporation, with the pumping rate of the first pump 31 remaining constant, the smaller the first sub-chamber 11 is relative to the film to be flashed, the faster the film can be prepared. However, the first sub-chamber 11 cannot be too small relative to the film to be flashed, otherwise it will easily lead to excessive gas disturbance around the film to be flashed, affecting the uniformity of the prepared film. Therefore, optionally, the distance S between the sidewall of the first sub-chamber 11 and the film to be flashed satisfies 5cm≤S≤30cm; the distance h between the top of the first sub-chamber 11 and the film to be flashed satisfies 15cm≤h≤20cm.

[0077] During the flash evaporation process, once the gas pressure in the connected chamber 10 reaches the preset pressure, the corresponding valves and vacuum pump are closed. It is understood that the chamber should be connected to a vacuum gauge to detect the gas pressure in the chamber 10.

[0078] Optional, such as Figure 1As shown, the flash evaporation device also includes a first vacuum gauge 41 and a second vacuum gauge 42. The first vacuum gauge 41 is connected to the first sub-chamber 11 and is used to detect the gas pressure in the first sub-chamber 11. The second vacuum gauge 42 is connected to the second sub-chamber 12 and is used to detect the gas pressure in the second sub-chamber 12.

[0079] It is conceivable that, such as Figure 1 As shown, if at least two sub-chambers in the flash evaporation device also include a third sub-chamber 13, the flash evaporation device may also include a third vacuum gauge 43, which is connected to the third sub-chamber 13 and is used to detect the gas pressure in the third sub-chamber 13.

[0080] Understandably, during the flash evaporation process, it is necessary to control whether or not to evacuate by controlling the connection status between the evacuation pump and the corresponding sub-chamber.

[0081] Therefore, optional, such as Figure 1 As shown, the flash evaporation device also includes a first regulating valve 51 and a second regulating valve 52. The first regulating valve 51 is located on the connection passage between the first sub-chamber 11 and the first suction pump 31. When the first regulating valve 51 is open, the first sub-chamber 11 and the first suction pump 31 are connected. When the first regulating valve 51 is closed, the first sub-chamber 11 and the first suction pump 31 are isolated from each other. The second regulating valve 52 is located on the connection passage between the second sub-chamber 12 and the second suction pump 32. When the second regulating valve 52 is open, the second sub-chamber 12 and the second suction pump 32 are connected. When the second regulating valve 52 is closed, the second sub-chamber 12 and the second suction pump 32 are isolated from each other.

[0082] Meanwhile, the first regulating valve 51 and the second regulating valve 52 can also regulate the pumping rate of the first air pump 31 and the second air pump 32 to the corresponding chambers, and when the first regulating valve 51 and the second regulating valve 52 are closed, the chambers connected to them can also be kept in a sealed state.

[0083] It is conceivable that if at least two sub-chambers in the flash evaporator also include a third sub-chamber 13, such as Figure 1 As shown, the third sub-chamber 13 is connected to a third vacuum pump 33. Optionally, the flash evaporation device may also include a third regulating valve 53. The third regulating valve 53 is located on the connection passage between the third sub-chamber 13 and the third vacuum pump 33. When the third regulating valve 53 is open, the third sub-chamber 13 and the third vacuum pump 33 are connected. When the third regulating valve 53 is closed, the third sub-chamber 13 and the third vacuum pump 33 are isolated. The third regulating valve 53 can also be used to regulate the vacuuming rate of the third vacuum pump 33 to the third sub-chamber 13. When the third regulating valve 53 is closed, the third sub-chamber 13 connected to it can also be kept in a sealed state.

[0084] During the flash evaporation process, the opening and closing of valves and vacuum pumps can be controlled manually or more conveniently using a control system.

[0085] Therefore, optionally, the flash evaporation device also includes a control system. The control system is used to, when flash evaporating the membrane, first open the first valve 21 to connect the first sub-chamber 11 and the second sub-chamber 12, and then start the second vacuum pump 32 to extract air. Once the air pressure in the connected first sub-chamber 11 and the second sub-chamber 12 reaches a preset pressure, the first valve 21 is then closed to isolate the first sub-chamber 11 and the second sub-chamber 12, and the second vacuum pump 32 is turned off, while the first vacuum pump 31 is started to extract air.

[0086] It is conceivable that if at least two sub-chambers also include a third sub-chamber 13, with the third sub-chamber 13 and the second sub-chamber 12 located on opposite sides of the first sub-chamber 11, and a second valve 22 provided between the first sub-chamber 11 and the third sub-chamber 13, and the third sub-chamber 13 connected to a third vacuum pump 33, the control system can optionally be used to, when flash evaporating the membrane to be flashed, first open the first valve 21 and the second valve 22 to connect the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, and start the second vacuum pump 32 and the third vacuum pump 33 to pump air. After the air pressure in the connected first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13 reaches the preset air pressure, then close the first valve 21 and the second valve 22 to isolate the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, and shut down the second vacuum pump 32 and the third vacuum pump 33, and start the first vacuum pump 31 to pump air.

[0087] After flash evaporation, the chamber needs to be restored to the atmospheric pressure state before flash evaporation to facilitate the removal of the obtained film and preparation for the next flash evaporation.

[0088] Therefore, optional, such as Figure 1 As shown, the flash evaporation device also includes a first gas filling line 61 and a second gas filling line 62. The first gas filling line 61 is provided with a first gas filling valve 71. When the first gas filling valve 71 is open, the first gas filling line 61 is connected to the first sub-chamber 11. When the first gas filling valve 71 is closed, the first gas filling line 61 and the first sub-chamber 11 are isolated from each other. The second gas filling line 62 is provided with a second gas filling valve 72. When the second gas filling valve 72 is open, the second gas filling line 62 is connected to the second sub-chamber 12. When the second gas filling valve 72 is closed, the second gas filling line 62 and the second sub-chamber 12 are isolated from each other.

[0089] It is conceivable that if at least two sub-chambers also include a third sub-chamber 13, the options could be, for example... Figure 1As shown, the flash evaporation device may also include a third gas filling line 63, on which a third gas filling valve 73 is provided. When the third gas filling valve 73 is open, the third gas filling line 63 and the third sub-chamber 13 are connected. When the third gas filling valve 73 is closed, the third gas filling line 63 and the third sub-chamber 13 are isolated.

[0090] It is understood that the embodiments of this application do not limit the number of sub-chambers. In addition to the chamber 10 listed in the above embodiments including two or three sub-chambers, the chamber 10 may also include multiple sub-chambers, which will not be listed here. The number of sub-chambers can be set according to the specific needs.

[0091] This application also provides a flash evaporation method, applied to the flash evaporation apparatus provided in any of the above embodiments, combined with... Figure 1 and Figure 2 As shown, the flash evaporation method includes:

[0092] S10: Open the first valve 21 to connect the first sub-chamber 11 and the second sub-chamber 12, and start the second air pump 32 to pump air.

[0093] In the initial stage of this flash evaporation, the film to be flashed can be evaporated at a small rate in the larger chamber that connects the first sub-chamber 11 and the second sub-chamber 12. This allows the gas in the larger chamber where the film to be flashed is located to decrease slowly, avoiding the problem of uneven film preparation caused by large gas disturbances due to the rapid flow of a large amount of gas in the chamber, which would purge the film surface.

[0094] S20: After the air pressure in the first sub-chamber 11 and the second sub-chamber 12 to be connected reaches the preset air pressure, close the first valve 21 to isolate the first sub-chamber 11 and the second sub-chamber 12, and turn off the second air pump 32 and turn on the first air pump 31 to pump air.

[0095] In the later stage of this flash evaporation, the film to be flashed can be evacuated at a relatively high evacuation rate only in the first sub-chamber 11, thereby achieving the purpose of flash evaporation. Since the amount of gas in the first sub-chamber 11 is small in this flash evaporation stage, the rapid vacuuming has little impact on the uniformity of the obtained film.

[0096] Optionally, if the flash evaporator includes at least two sub-chambers, it further includes a third sub-chamber 13. The third sub-chamber 13 and the second sub-chamber 12 are located on opposite sides of the first sub-chamber 11. A second valve 22 is provided between the first sub-chamber 11 and the third sub-chamber 13. The third sub-chamber 13 is connected to a third vacuum pump 33. The vacuum rate of the first vacuum pump 31 is greater than the vacuum rate of the third vacuum pump 33. Figure 1 and Figure 3 As shown, the flash evaporation method further includes:

[0097] S11: While opening the first valve 21, open the second valve 22 to connect the first sub-chamber 11, the second sub-chamber 12 and the third sub-chamber 13. At the same time as opening the second air pump 32 to pump air, open the third air pump 33 to pump air.

[0098] In the initial stage of this flash evaporation, since the second sub-chamber 12 connected to the second pump 32 and the third sub-chamber 13 connected to the third pump 33 are symmetrical with respect to the first sub-chamber 11 where the film to be flashed is located, when the second pump 32 and the third pump 33 are turned on simultaneously for evaporation, the evaporation of the first sub-chamber 11 is more uniform. Therefore, in this flash evaporation stage, the film to be flashed can be evaporated by a smaller and more uniform evaporation field in the larger chamber where the first sub-chamber 11, the second sub-chamber 12 and the third sub-chamber 13 are connected. This makes the gas in the first sub-chamber 11 where the film to be flashed is located decrease slowly and uniformly, avoiding the problem of uneven film preparation caused by huge gas disturbances due to the rapid flow of a large amount of gas in the chamber, which would purge the film surface.

[0099] S21: After the air pressure in the first sub-chamber 11, the second sub-chamber 12 and the third sub-chamber 13 to be connected reaches the preset air pressure, the first valve 21 is closed and the second valve 22 is closed at the same time to isolate the first sub-chamber 11, the second sub-chamber 12 and the third sub-chamber 13. At the same time as the second air pump 32 is closed, the third air pump 33 is closed and the first air pump 31 is turned on to pump air.

[0100] In the later stage of this flash evaporation, the film to be flashed can be evacuated at a relatively high evacuation rate only in the first sub-chamber 11, thereby achieving the purpose of flash evaporation. Since the amount of gas in the first sub-chamber 11 is small in this flash evaporation stage, the rapid evacuation method has little impact on the uniformity of the obtained film.

[0101] In the embodiments of this application, it is conceivable that if the pumping fields on both sides of the first sub-chamber 11 are symmetrical in direction and have the same size, the pumping speed in the first sub-chamber 11 where the flash-evaporated film is located will be more uniform, and the uniformity of the prepared film will be better.

[0102] Therefore, optionally, the second sub-chamber 12 and the third sub-chamber 13 are respectively provided with a first air extraction port and a second air extraction port. The first air extraction port is connected to the first air extraction pump 31, and the second air extraction port is connected to the second air extraction pump 32. The first air extraction port and the second air extraction port are symmetrically arranged relative to the first sub-chamber 11, so that the air extraction field directions on both sides of the first sub-chamber 11 are symmetrical.

[0103] Optionally, the pumping rate of the second pump 32 is equal to the pumping rate of the third pump 33, so that the pumping fields on both sides of the first sub-chamber 11 are of the same size.

[0104] It should be noted that, in the later stage of flash evaporation in any of the above embodiments, in order to achieve the flash evaporation purpose in a shorter time, the preset gas pressure value should be as close as possible to the gas pressure value required by the flash evaporation process. Therefore, optionally, the relationship between the preset gas pressure value P1 and the saturated vapor pressure P0 of the solvent in the film to be flashed satisfies: P0≤P1≤P0+200pa, where the saturated vapor pressure P0 of the solvent is the pressure that the liquid and vapor of the solvent have in a phase equilibrium state under a closed environment and a preset temperature.

[0105] It is understandable that the size of the chamber containing the film to be flashed has a significant impact on the uniformity of the prepared film during different flash evaporation stages. Specifically, in the initial stage of flash evaporation, with the pumping rates of the second pump 32 and the third pump 33 remaining constant, the larger the chamber connecting the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, the smaller the rate at which the gas in the first sub-chamber 11 containing the film to be flashed decreases, and thus the better the uniformity of the prepared film. Therefore, optionally, along the first direction, the relationship between the length d1 of the film sample and the length d2 of the chamber 10 satisfies: d2 ≥ 2d1, and the first direction is parallel to the direction in which the first sub-chamber 11 and the second sub-chamber 12 are arranged.

[0106] In the later stage of flash evaporation, with the pumping rate of the first pump 31 remaining constant, the smaller the first sub-chamber 11 is relative to the film to be flashed, the faster the film can be prepared. However, the first sub-chamber 11 cannot be too small relative to the film to be flashed, otherwise it will easily lead to excessive gas disturbance around the film to be flashed, affecting the uniformity of the prepared film. Therefore, optionally, the distance S between the sidewall of the first sub-chamber 11 and the film to be flashed satisfies 5cm≤S≤30cm; the distance h between the top of the first sub-chamber 11 and the film to be flashed satisfies 15cm≤h≤20cm.

[0107] During the flash evaporation process, once the gas pressure in the connected chamber 10 reaches the preset pressure, the corresponding valves and vacuum pump are closed. It is understood that the chamber should be connected to a vacuum gauge to detect the gas pressure in the chamber 10.

[0108] Optional, such as Figure 1 As shown, the flash evaporation device also includes a first vacuum gauge 41 and a second vacuum gauge 42. The first vacuum gauge 41 is connected to the first sub-chamber 11 and is used to detect the gas pressure in the first sub-chamber 11. The second vacuum gauge 42 is connected to the second sub-chamber 12 and is used to detect the gas pressure in the second sub-chamber 12.

[0109] It is conceivable that, such as Figure 1As shown, if at least two sub-chambers in the flash evaporation device also include a third sub-chamber 13, the flash evaporation device may also include a third vacuum gauge 43, which is connected to the third sub-chamber 13 and is used to detect the gas pressure in the third sub-chamber 13.

[0110] Understandably, during the flash evaporation process, it is necessary to control whether or not to evacuate by controlling the connection status between the evacuation pump and the corresponding sub-chamber.

[0111] Therefore, optional, such as Figure 1 As shown, the flash evaporation device also includes a first regulating valve 51 and a second regulating valve 52. The first regulating valve 51 is located on the connection passage between the first sub-chamber 11 and the first suction pump 31. When the first regulating valve 51 is open, the first sub-chamber 11 and the first suction pump 31 are connected. When the first regulating valve 51 is closed, the first sub-chamber 11 and the first suction pump 31 are isolated from each other. The second regulating valve 52 is located on the connection passage between the second sub-chamber 12 and the second suction pump 32. When the second regulating valve 52 is open, the second sub-chamber 12 and the second suction pump 32 are connected. When the second regulating valve 52 is closed, the second sub-chamber 12 and the second suction pump 32 are isolated from each other.

[0112] Meanwhile, the first regulating valve 51 and the second regulating valve 52 can also regulate the pumping rate of the first air pump 31 and the second air pump 32 to the corresponding chambers, and when the first regulating valve 51 and the second regulating valve 52 are closed, the chambers connected to them can also be kept in a sealed state.

[0113] It is conceivable that if at least two sub-chambers in the flash evaporator also include a third sub-chamber 13, such as Figure 1 As shown, the third sub-chamber 13 is connected to a third vacuum pump 33. Optionally, the flash evaporation device may also include a third regulating valve 53. The third regulating valve 53 is located on the connection passage between the third sub-chamber 13 and the third vacuum pump 33. When the third regulating valve 53 is open, the third sub-chamber 13 and the third vacuum pump 33 are connected. When the third regulating valve 53 is closed, the third sub-chamber 13 and the third vacuum pump 33 are isolated. The third regulating valve 53 can also be used to regulate the vacuuming rate of the third vacuum pump 33 to the third sub-chamber 13. When the third regulating valve 53 is closed, the third sub-chamber 13 connected to it can also be kept in a sealed state.

[0114] During the flash evaporation process, the opening and closing of valves and vacuum pumps can be controlled manually or more conveniently using a control system.

[0115] Therefore, optionally, the flash evaporation device also includes a control system. The control system is used to, when flash evaporating the membrane, first open the first valve 21 to connect the first sub-chamber 11 and the second sub-chamber 12, and then start the second vacuum pump 32 to extract air. Once the air pressure in the connected first sub-chamber 11 and the second sub-chamber 12 reaches a preset pressure, the first valve 21 is then closed to isolate the first sub-chamber 11 and the second sub-chamber 12, and the second vacuum pump 32 is turned off, while the first vacuum pump 31 is started to extract air.

[0116] It is conceivable that if at least two sub-chambers also include a third sub-chamber 13, with the third sub-chamber 13 and the second sub-chamber 12 located on opposite sides of the first sub-chamber 11, and a second valve 22 provided between the first sub-chamber 11 and the third sub-chamber 13, and the third sub-chamber 13 connected to a third vacuum pump 33, the control system can optionally be used to, when flash evaporating the membrane to be flashed, first open the first valve 21 and the second valve 22 to connect the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, and start the second vacuum pump 32 and the third vacuum pump 33 to pump air. After the air pressure in the connected first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13 reaches the preset air pressure, then close the first valve 21 and the second valve 22 to isolate the first sub-chamber 11, the second sub-chamber 12, and the third sub-chamber 13, and shut down the second vacuum pump 32 and the third vacuum pump 33, and start the first vacuum pump 31 to pump air.

[0117] After flash evaporation, the chamber needs to be restored to the atmospheric pressure state before flash evaporation to facilitate the removal of the obtained film and preparation for the next flash evaporation.

[0118] Therefore, optional, such as Figure 1 As shown, the flash evaporation device also includes a first gas filling line 61 and a second gas filling line 62. The first gas filling line 61 is provided with a first gas filling valve 71. When the first gas filling valve 71 is open, the first gas filling line 61 is connected to the first sub-chamber 11. When the first gas filling valve 71 is closed, the first gas filling line 61 and the first sub-chamber 11 are isolated from each other. The second gas filling line 62 is provided with a second gas filling valve 72. When the second gas filling valve 72 is open, the second gas filling line 62 is connected to the second sub-chamber 12. When the second gas filling valve 72 is closed, the second gas filling line 62 and the second sub-chamber 12 are isolated from each other.

[0119] It is conceivable that if at least two sub-chambers also include a third sub-chamber 13, the options could be, for example... Figure 1 As shown, the flash evaporation device may also include a third gas filling line 63, on which a third gas filling valve 73 is provided. When the third gas filling valve 73 is open, the third gas filling line 63 and the third sub-chamber 13 are connected. When the third gas filling valve 73 is closed, the third gas filling line 63 and the third sub-chamber 13 are isolated.

[0120] It is understood that the embodiments of this application do not limit the number of sub-chambers. In addition to the chamber 10 listed in the above embodiments including two or three sub-chambers, the chamber 10 may also include multiple sub-chambers, which will not be listed here. The number of sub-chambers can be set according to the specific needs.

[0121] As can be seen from the above, the flash evaporation apparatus and flash evaporation method provided in this application embodiment can bring the gas pressure in the first sub-chamber 11 where the film to be flashed is located to the gas pressure required for the flash evaporation process in a short time, and the pumping speed is relatively uniform throughout the entire pumping process, thereby preparing a uniform perovskite film.

[0122] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0123] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flash apparatus, characterized by, The flash evaporator comprises: a chamber comprising at least two sub-chambers, the at least two sub-chambers comprising a first sub-chamber and a second sub-chamber located on one side of the first sub-chamber, the first sub-chamber being used for placing a film to be flash evaporated; a first valve is arranged between the first sub-chamber and the second sub-chamber, when the first valve is opened, the first sub-chamber and the second sub-chamber are connected, when the first valve is closed, the first sub-chamber and the second sub-chamber are isolated; the first sub-chamber is connected with a first air pump, the second sub-chamber is connected with a second air pump, the air pumping rate of the first air pump is greater than the air pumping rate of the second air pump; the flash evaporator further comprises a control system; the control system is used for, when flash evaporating the film to be flash evaporated, first opening the first valve, connecting the first sub-chamber and the second sub-chamber, opening the second air pump to pump air, after the air pressure in the connected first sub-chamber and second sub-chamber reaches a preset air pressure, closing the first valve to isolate the first sub-chamber and the second sub-chamber, closing the second air pump, and opening the first air pump to pump air.

2. The flash device of claim 1, wherein the at least two sub-chambers further comprise a third sub-chamber, the third sub-chamber and the second sub-chamber are located on the opposite sides of the first sub-chamber; a second valve is arranged between the first sub-chamber and the third sub-chamber, when the second valve is opened, the first sub-chamber and the third sub-chamber are connected, when the second valve is closed, the first sub-chamber and the third sub-chamber are isolated; the third sub-chamber is connected with a third air pump, the air pumping rate of the first air pump is greater than the air pumping rate of the third air pump.

3. The flash device of claim 2, wherein, the air pumping rate of the second air pump is equal to the air pumping rate of the third air pump.

4. The flash evaporator of claim 1, wherein the flash evaporator further comprises a first vacuum gauge and a second vacuum gauge; the first vacuum gauge is connected with the first sub-chamber and is used for detecting the air pressure in the first sub-chamber; the second vacuum gauge is connected with the second sub-chamber and is used for detecting the air pressure in the second sub-chamber.

5. The flash evaporator of claim 1, wherein, the flash evaporator further comprises a first regulating valve and a second regulating valve; the first regulating valve is arranged on the connecting passage between the first sub-chamber and the first air pump, when the first regulating valve is opened, the first sub-chamber and the first air pump are connected, when the first regulating valve is closed, the first sub-chamber and the first air pump are isolated; the second regulating valve is arranged on the connecting passage between the second sub-chamber and the second air pump, when the second regulating valve is opened, the second sub-chamber and the second air pump are connected, when the second regulating valve is closed, the second sub-chamber and the second air pump are isolated.

6. The flash evaporator of claim 1, wherein, the flash evaporator further comprises a first air charging pipeline and a second air charging pipeline; a first air charging valve is arranged on the first air charging pipeline, when the first air charging valve is opened, the first air charging pipeline and the first sub-chamber are connected, when the first air charging valve is closed, the first air charging pipeline and the first sub-chamber are isolated; The second inflation pipeline is provided with a second inflation valve, when the second inflation valve is opened, the second inflation pipeline and the second sub-chamber are communicated, when the second inflation valve is closed, the second inflation pipeline and the second sub-chamber are isolated.

7. A flash evaporation method characterized by, The flash evaporation method is applied to the flash evaporation device of any one of claims 1-6, and the flash evaporation method comprises: The first valve is opened, the first sub-chamber and the second sub-chamber are communicated, and the second evacuation pump is started to evacuate; After the air pressure in the communicated first sub-chamber and second sub-chamber reaches a preset air pressure, the first valve is closed, the first sub-chamber and the second sub-chamber are isolated, the second evacuation pump is closed, and the first evacuation pump is started to evacuate.

8. The flash process of claim 7 wherein, The flash evaporation device further comprises a third sub-chamber, the third sub-chamber and the second sub-chamber are located on opposite sides of the first sub-chamber, a second valve is arranged between the first sub-chamber and the third sub-chamber, the third sub-chamber is connected with a third evacuation pump, and the evacuation rate of the first evacuation pump is greater than the evacuation rate of the third evacuation pump. The flash evaporation method further comprises: The first valve is opened, the first sub-chamber, the second sub-chamber and the third sub-chamber are communicated, and the third evacuation pump is started to evacuate at the same time that the second evacuation pump is started to evacuate; After the air pressure in the communicated first sub-chamber, second sub-chamber and third sub-chamber reaches a preset air pressure, the first valve is closed at the same time that the second valve is closed, the first sub-chamber, the second sub-chamber and the third sub-chamber are isolated, the third evacuation pump is closed at the same time that the second evacuation pump is closed, and the first evacuation pump is started to evacuate.

9. The flash process according to claim 7 or 8, characterized in that, The relationship between the preset air pressure value P1 and the saturated vapor pressure P0 of the solvent in the flash-evaporated film satisfies: P0≤P1≤P0+200pa, and the saturated vapor pressure P0 of the solvent is the pressure required for the liquid and vapor of the solvent to be in a phase equilibrium state under a closed environment and a preset temperature.

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