A roll-to-roll flexible functional layer preparation apparatus and method

Abstract

A roll-to-roll flexible functional layer preparation device and method, the device comprising a unwinding unit, a coating unit, a first storage unit, a vacuum drying unit, a second storage unit, a heat drying unit and a winding unit. The vacuum drying unit comprises an upper housing, a lower housing and a vacuum pumping subunit. In response to receiving a normal pressure working instruction, the upper housing and the lower housing are gap arranged, the gap is for substrate transmission; the first storage unit discharges; the second storage unit feeds. In response to receiving a low pressure working instruction, the first storage unit stops discharging; the second storage unit stops feeding; the upper housing and the lower housing are extruded and arranged, defining a low pressure cavity with built-in part of the substrate, and vacuum drying. It can meet the high performance requirements and continuous production requirements of specific flexible functional layers. Especially suitable for continuous production of flexible perovskite functional layers, and the perovskite functional layer has high purity and good crystallization effect, which helps to improve the photoelectric conversion efficiency of perovskite solar cells.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to an apparatus and method for preparing roll-to-roll flexible functional layers. Background Technology

[0002] Roll-to-roll coating technology is widely used in papermaking, printing, packaging, and substrate manufacturing. However, with the rapid development of flexible functional layer devices such as new energy, new materials, optical films, and optoelectronic films, conventional roll-to-roll coating technology is difficult to meet the preparation requirements of specific flexible functional layers.

[0003] Taking flexible perovskite functional layers as an example, perovskite thin-film solar cells are hailed as the future "star of photovoltaics" due to their advantages of simple manufacturing process, low cost, and high photoelectric conversion efficiency. If roll-to-roll flexible coating technology is used for the perovskite functional layer, it can maximize the balance between the demand for flexible devices and the need for continuous industrial production.

[0004] In existing technologies, when fabricating roll-to-roll flexible perovskite functional layers, the substrate coated with a wet film is typically directly transferred to an oven for heating and then rolled up. However, this fabrication method has certain drawbacks. The perovskite functional layer exhibits poor crystallization, such as disordered crystal phases and small crystal size, leading to a significant reduction in the transport distance of charge carriers within the crystal and a high recombination probability, directly affecting the photoelectric conversion efficiency of photovoltaic devices.

[0005] Therefore, how to provide a roll-to-roll flexible functional layer fabrication apparatus and method that can take into account both the high performance requirements and continuous production requirements for specific flexible functional layers has become an urgent problem to be solved. Summary of the Invention

[0006] To address at least one problem existing in the prior art, the purpose of this application is to provide a roll-to-roll flexible functional layer fabrication apparatus and method that can simultaneously meet the high performance requirements and continuous production needs of specific flexible functional layers. It is particularly suitable for the continuous production of flexible perovskite functional layers, and the fabricated perovskite functional layers exhibit high purity and excellent crystallization, thus contributing to improved photoelectric conversion efficiency of perovskite solar cells.

[0007] To achieve the above objectives, the roll-to-roll flexible functional layer preparation apparatus provided in this application includes an unwinding unit, a coating unit, a first material storage unit, a vacuum drying unit, a second material storage unit, a heat drying unit, and a winding unit arranged sequentially along the substrate transport direction.

[0008] The vacuum drying unit includes an upper shell, a lower shell, and a vacuum pumping subunit; it is used to vacuum dry the coated substrate.

[0009] In response to receiving an atmospheric pressure operating command, a gap is formed between the upper and lower shells of the vacuum drying unit, the gap being used for substrate transfer; the first storage unit discharges material, and the second storage unit feeds material.

[0010] In response to receiving a low-pressure operating command, the first storage unit stops discharging; the second storage unit stops feeding; the upper shell and the lower shell are pressed together to define a low-pressure cavity containing a portion of the substrate; the substrate in the low-pressure cavity is vacuum dried.

[0011] Preferably, the feeding speed of the first storage unit is matched with the unwinding speed of the unwinding unit; the discharging speed of the first storage unit is greater than the feeding speed.

[0012] The discharge speed of the second storage unit is matched with the winding speed of the winding unit; the feeding speed of the second storage unit is greater than the storage speed.

[0013] The unwinding speed of the unwinding unit and / or the winding speed of the winding unit are set online at a constant speed.

[0014] Preferably, the vacuum pumping subunit includes a dry pump and a molecular pump; the vacuum holding time ranges from 10s to 20s.

[0015] Preferably, the vacuum drying unit further includes a temperature control subunit for controlling the temperature of the low-pressure cavity.

[0016] Preferably, the device further comprises,

[0017] A barometer is used to measure the air pressure in the low-pressure chamber of the vacuum drying unit.

[0018] A controller is used to control the operating state of the vacuum drying unit based on the air pressure value.

[0019] Preferably, the coating unit is configured to coat the substrate continuously or intermittently;

[0020] The substrate subjected to intermittent coating includes a coating area and an intermittent area; under low-pressure operating conditions, the substrate area squeezed between the upper housing and the lower housing at least partially corresponds to the intermittent area.

[0021] Preferably, the functional layer is a perovskite functional layer.

[0022] To achieve the above objectives, this application also provides a roll-to-roll flexible functional layer fabrication method, employing the roll-to-roll flexible functional layer fabrication apparatus described above, the method comprising:

[0023] The unwinding unit releases the substrate;

[0024] The coating unit coats the substrate, and the first storage unit feeds the coated substrate.

[0025] In response to receiving an atmospheric pressure operating command, the upper and lower shells of the vacuum drying unit are spaced apart, the first storage unit discharges material, and the second storage unit feeds material.

[0026] In response to receiving a low-pressure operating command, the first storage unit stops discharging; the second storage unit stops feeding; the upper shell and the lower shell are pressed together to define the low-pressure cavity; after vacuuming, the substrate in the low-pressure cavity is vacuum dried;

[0027] The second storage unit discharges the dried substrate;

[0028] The drying unit heats the substrate, and the winding unit winds up the dried substrate.

[0029] Preferably, the device further includes a barometer and a controller; at the controller end, the method further includes,

[0030] The first timing begins at the start of the vacuuming process;

[0031] Obtain the air pressure value of the low-pressure cavity as measured by the barometer;

[0032] In response to the air pressure value being equal to the air pressure threshold and the duration of the first timing being less than the first duration threshold, a second timing is initiated, and when the duration of the second timing reaches the second duration threshold, the atmospheric pressure operation command is sent to the vacuum drying unit.

[0033] More preferably, the method further includes,

[0034] If the duration of the first timing reaches a third duration threshold, and the air pressure value remains greater than the air pressure threshold, then an air pressure anomaly is determined, and an anomaly strategy is initiated; wherein,

[0035] The third duration threshold is greater than the first duration threshold;

[0036] The abnormal strategy includes performing a third timing, and when the duration of the third timing reaches a fourth duration threshold, sending the atmospheric pressure operation command to the vacuum drying unit.

[0037] The anomaly strategy also includes at least one of the following:

[0038] Reduce the unwinding speed and adjust the coating parameters of the coating unit accordingly;

[0039] Reduce the winding speed and adjust the drying temperature of the drying unit accordingly;

[0040] Increase the discharge speed of the first storage unit and the feed speed of the second storage unit.

[0041] This application discloses a roll-to-roll flexible functional layer fabrication apparatus and method. After the coating unit, a dedicated first storage unit, vacuum drying unit, and second storage unit are provided. The vacuum drying unit consists of an upper shell, a lower shell, and a vacuum extraction subunit. Upon receiving a normal pressure operating command, a gap is formed between the upper and lower shells of the vacuum drying unit to allow for the transfer of coated substrate, with the first storage unit discharging and the second storage unit feeding. Upon receiving a low-pressure operating command, the first storage unit stops discharging, the second storage unit stops feeding, and the upper and lower shells are compressed together to define a low-pressure cavity containing a portion of the substrate. The substrate within this low-pressure cavity is then vacuum-dried. This approach balances the high-performance requirements of specific flexible functional layers with the need for continuous production. It is particularly suitable for the continuous production of flexible perovskite functional layers, and the prepared perovskite functional layers exhibit high purity and excellent crystallinity, contributing to improved photoelectric conversion efficiency of perovskite solar cells.

[0042] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. Attached Figure Description

[0043] The accompanying drawings are provided to further illustrate the present application and form part of the specification. Together with the embodiments of the present application, they serve to explain the present application but do not constitute a limitation thereof. In the drawings:

[0044] Figure 1 This is a schematic diagram of the structure of flat plate coating in the prior art;

[0045] Figure 2 This is a schematic diagram of the roll-to-roll coating structure according to an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of the roll-to-roll flexible functional layer fabrication apparatus according to an embodiment of this application;

[0047] Figure 4 This is a schematic diagram of the structure of a vacuum drying unit according to an embodiment of this application;

[0048] Figure 5 This is a schematic diagram of the structure of a continuously coated substrate according to an embodiment of this application;

[0049] Figure 6 This is a schematic diagram of the structure of an intermittently coated substrate according to an embodiment of this application;

[0050] Figure 7 This is a flowchart of a roll-to-roll flexible functional layer fabrication method according to an embodiment of this application;

[0051] Figure 8 This is a flowchart of a roll-to-roll flexible functional layer fabrication method according to another embodiment of this application.

[0052] Specifically, the following reference numerals are included:

[0053] Coating die for flatbed coating - 11; Coating substrate for flatbed coating - 12; Coating film layer for flatbed coating - 13;

[0054] Roll-to-roll coating die-21; roll-to-roll coating substrate-22; roll-to-roll coating film-23; roll-to-roll coating back roller-24.

[0055] Roll-to-roll flexible functional layer preparation device - 300; Unwinding unit - 310; Coating unit - 320; First material storage unit - 330; Vacuum drying unit - 340; Upper shell - 341; Lower shell - 342; Exhaust hole - 343; Inflation hole - 344; Barometer - 345; Second material storage unit - 350; Heat drying unit - 360; Rewinding unit - 370; Guide roller - 371; Protective film unwinding roller - 372; Protective film pressure roller - 373; Rewinding roller - 374;

[0056] Substrate - 400; Coated area - 410; Intermittent area - 420. Detailed Implementation

[0057] Embodiments of this application will now be described in more detail with reference to the accompanying drawings. While some embodiments of this application are shown in the drawings, it should be understood that this application can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this application. It should be understood that the drawings and embodiments of this application are for illustrative purposes only and are not intended to limit the scope of protection of this application.

[0058] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure, element or device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0059] It should be understood that the steps described in the method embodiments of this application may be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of this application is not limited in this respect.

[0060] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0061] It should be noted that the concepts of "first" and "second" mentioned in this application are only used to distinguish different devices, modules, units, data or locations, and are not used to limit the order or interdependence of the functions performed by these devices, modules, units, data or locations.

[0062] It should be noted that the terms "one" and "multiple" used in this application are illustrative rather than restrictive, and those skilled in the art should understand that, unless explicitly stated otherwise in the context, they should be understood as "one or more". "Multiple" should be understood as two or more.

[0063] First, it should be noted that at present, whether in scientific research or industrialization, the vast majority of research groups or companies use flat-plate coating to prepare functional layers. That is, using a rigid substrate, such as glass or silicon wafer, to prepare a multilayer structure on its surface.

[0064] For flat plate coating, such as Figure 1 As shown, flatbed coating can coat a coating film 13 onto a flat substrate 12 using a coating die 11. Since the flatbed coating substrate 12 is in units of sheets, the coating of each substrate is an independent process. A start and stop action is required when changing sheets. This not only affects production efficiency and is not conducive to large-scale continuous production, but also makes it very difficult to control the uniformity of the quality at the start and stop edges of the coating on each substrate.

[0065] Compared with flat plate coating, such as Figure 2 As shown, roll-to-roll coating can coat the substrate 22 on the coating back roller 24 with a coating film layer 23 through the coating die 21. This roll-to-roll coating does not require frequent die changes, has high production efficiency, and is suitable for continuous production applications. In a relatively long process, as long as the liquid supply and substrate conveying are maintained, a continuous and stable functional coating can be prepared.

[0066] However, in the fabrication of roll-to-roll flexible perovskite functional layers, the substrate coated with a wet film is typically directly transferred to an oven for heat drying and then wound up. This method results in poor crystallization of the perovskite functional layer, such as disordered crystal phases and small crystal sizes. This significantly reduces the transport distance of charge carriers within the crystal, increases the recombination probability, and directly affects the photoelectric conversion efficiency of photovoltaic devices.

[0067] Therefore, this application provides a roll-to-roll flexible functional layer fabrication apparatus and method that can balance the high performance requirements for specific flexible functional layers with the need for continuous production. It is particularly suitable for the continuous production of flexible perovskite functional layers, and the fabricated perovskite functional layers have high purity and excellent crystallization, which helps to improve the photoelectric conversion efficiency of perovskite solar cells.

[0068] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0069] Figure 3 This is a schematic diagram of the roll-to-roll flexible functional layer fabrication apparatus according to an embodiment of this application. Figure 3 As shown, the roll-to-roll flexible functional layer preparation apparatus 300 includes an unwinding unit 310, a coating unit 320, a first material storage unit 330, a vacuum drying unit 340, a second material storage unit 350, a heat drying unit 360, and a winding unit 370 arranged sequentially along the substrate transport direction.

[0070] Among them, such as Figure 3 and Figure 4 As shown, the vacuum drying unit 340 includes an upper housing 341, a lower housing 342, and a vacuum pumping subunit (not shown in the figure); it is used to vacuum dry the coated substrate 400.

[0071] In response to receiving an atmospheric pressure operating command, the upper housing 341 and the lower housing 342 of the vacuum drying unit 340 are separated to allow the substrate 400 to be transported; and the first storage unit 330 discharges material and the second storage unit 350 feeds material.

[0072] In response to receiving a low-pressure operating command, the first storage unit 330 stops discharging; the second storage unit 350 stops feeding; the upper housing 341 and the lower housing 342 are pressed together to define a cavity containing a portion of the substrate through the upper vacuum chamber of the upper housing 341 and the lower vacuum chamber of the lower housing 342. Then, the vacuuming subunit evacuates the cavity through the exhaust port 343 to vacuum dry the substrate in the low-pressure cavity until the next atmospheric pressure operating command is received, at which point the vacuum drying unit 340 is opened by filling with gas through the inflation port 344.

[0073] In specific examples, such as Figure 3As shown, the winding unit 370 may include a guide roller 371, a protective film unwinding roller 372, a protective film pressure roller 373, and a winding roller 374.

[0074] It is understood that the flexible functional layer prepared in this application can be a perovskite flexible functional layer, or other flexible functional layers such as new energy, new materials, optical films, and optoelectronic films, as long as it is a crystalline functional layer. This application does not impose any specific restrictions on it.

[0075] It should be noted that for functional layers that need to be in a crystalline state, the crystallization process includes three stages: crystal nucleation in the solution, crystal growth, and crystal maturation. Among these, crystal nucleation is the first and most crucial step in the crystallization process, directly affecting the crystallization effect and thus the function of the corresponding device.

[0076] The principle of this application is as follows: Under low-pressure operating conditions, the low-pressure environment reduces the collision frequency between functional layer material molecules, making it easier for these molecules to detach from the solid surface, thereby increasing the evaporation rate of the functional layer wet film in the cavity. Furthermore, the evaporated functional layer material molecules diffuse along the low-pressure direction in the vacuum cavity, reducing the gas concentration in the vicinity of the functional layer wet film and further contributing to an increased evaporation rate. In other words, under low-pressure conditions (such as a vacuum environment with a pressure below 1 Pa), functional layer material molecules easily adhere to the crystal surface and form high-quality crystal nuclei through efficient evaporation and sublimation. The crystal nucleus is the starting point for crystal growth, providing an ordered structure that allows more molecules to adhere and arrange into large-sized grains with excellent uniformity. In addition, vacuum drying after coating helps reduce crystal impurities, resulting in high-purity crystals.

[0077] Therefore, in the roll-to-roll flexible functional layer preparation apparatus 300 of this application embodiment, after the coating unit 320, a dedicated first storage unit 330, a vacuum drying unit 340, and a second storage unit 350 are provided for the preparation of high-performance roll-to-roll flexible functional layers suitable for continuous production. The vacuum drying unit 340 is used to generate high-quality crystal nuclei, and the first storage unit 330 and the second storage unit 350 are used to ensure that the application of the vacuum drying unit 340 is compatible with the continuous production of roll-to-roll flexible functional layers.

[0078] Specifically, on the one hand, during normal pressure operation, the upper housing 341 of the vacuum drying unit 340 is opened relative to the lower housing 342. At this time, the first storage unit 330 discharges the coated substrate 400 stored inside. The substrate 400 is then conveyed to the second storage unit 350 through the gap between the upper housing 341 and the lower housing 342. The second storage unit 350 feeds the substrate until all the corresponding substrates 400 in the vacuum drying unit 340 are un-vacuum dried. Then, the first storage unit 330, the vacuum drying unit 340, and the second storage unit 350 are controlled to enter a low-pressure operating state. On the other hand, during low-pressure operation, the first storage unit 330 stops discharging, the second storage unit 350 stops feeding, and the upper housing 341 and the lower housing 342 of the vacuum drying unit 340 are pressed together to define a low-pressure cavity containing a portion of the substrate 400. The substrate in the low-pressure cavity is then vacuum dried. This cyclical operation enables the substrate to undergo continuous online unwinding, coating, vacuum drying, heat drying, and rewinding processes.

[0079] Therefore, the roll-to-roll flexible functional layer fabrication apparatus of this application can simultaneously meet the high performance requirements and continuous production needs of specific flexible functional layers. It is particularly suitable for the continuous production of flexible perovskite functional layers, and the fabricated perovskite functional layers have high purity and excellent crystallization effect, which helps to improve the photoelectric conversion efficiency of perovskite solar cells.

[0080] Preferably, the feeding speed of the first storage unit 330 is matched with the unwinding speed of the unwinding unit 310; the discharge speed of the first storage unit 330 is greater than the feeding speed. The discharge speed of the second storage unit 350 is matched with the winding speed of the winding unit 370; the feeding speed of the second storage unit 350 is greater than the storage speed. Furthermore, the unwinding speed of the unwinding unit 310 is set online at a uniform speed, or the winding speed of the winding unit 370 is set online at a uniform speed, or both the unwinding speed of the unwinding unit 310 and the winding speed of the winding unit 370 are set online at a uniform speed. That is, by controlling the feeding and discharging speeds of the first storage unit 330 and the second storage unit 350, the vacuum drying process is matched with the transmission and operation of the preceding and following steps, thus achieving both the process effects of the online process (such as coating effect, heat drying effect, etc.) and the online matching effect of the preceding and following steps.

[0081] Preferably, the vacuum pumping subunit includes a dry pump and a molecular pump. By combining the dry pump and the molecular pump for vacuuming, a high-efficiency and high-quality vacuuming effect can be achieved. In a specific example, for the vacuum drying of the perovskite functional layer, the vacuum holding time after vacuuming is in the range of 10s-20s.

[0082] Preferably, the vacuum drying unit further includes a temperature control subunit (not shown in the figure) for controlling the temperature of the low-pressure chamber. Compared with the related technology of directly subjecting the coated wet film to atmospheric pressure and high-temperature annealing, this embodiment not only adds a vacuum drying unit, but also adopts an independent temperature control method to specifically control a specific nucleation temperature, which helps to further improve the crystallization quality and crystallization efficiency.

[0083] Preferably, such as Figure 4 As shown, the preparation apparatus also includes a barometer 345 and a controller (not shown in the figure). The barometer 345 is used to measure the air pressure in the low-pressure chamber of the vacuum drying unit 340. The controller is used to control the operating state of the vacuum drying unit 340 based on the air pressure value.

[0084] In this embodiment, the controller can be specifically used to: start a first timing when vacuuming begins; acquire the pressure value of the low-pressure cavity measured by the barometer 345; and, in response to the pressure value being equal to a pressure threshold and the duration of the first timing being less than a first duration threshold, start a second timing, and when the duration of the second timing reaches a second duration threshold, send an atmospheric pressure operation command to the vacuum drying unit 340.

[0085] In other words, upon receiving the low-pressure operating command, the first storage unit 330 stops discharging material, and the second storage unit 350 stops feeding material. Then, the upper shell 341 and lower shell 342 of the vacuum drying unit 340 compress a portion of the substrate 400 to form a cavity, begin vacuuming, start the first timing, and acquire the air pressure value of the low-pressure cavity. If the measured air pressure value equals the air pressure threshold (e.g., 1 Pa) within a preset time range (first time threshold), i.e., the target vacuum environment is reached, then the control starts the vacuum pressure holding time (second timing). If the vacuum pressure holding time reaches the target time (i.e., the second time threshold, e.g., 20 s), the controller sends a normal pressure operating command to the vacuum drying unit 340 so that the vacuum drying unit 340 opens its cavity and delivers the substrate 400.

[0086] More preferably, the controller can also be used to: determine an air pressure anomaly and initiate an anomaly strategy in response to the first timing duration reaching a third duration threshold and the air pressure value remaining greater than the air pressure threshold.

[0087] The third duration threshold is greater than the first duration threshold. When executing the abnormal strategy, the controller is specifically used to: perform a third timing, and when the duration of the third timing reaches the fourth duration threshold, send an atmospheric pressure operation command to the vacuum drying unit 340.

[0088] In other words, if the measured air pressure value is consistently higher than the air pressure threshold (e.g., 1 Pa) for an excessively long period after the vacuuming begins (reaching the third time threshold), thus failing to achieve the target vacuum environment, an air pressure anomaly is identified, and an anomaly strategy is activated.

[0089] Specifically, when executing the abnormal strategy, the controller can perform a third timing to preferably perform low-pressure drying for a certain holding time (fourth duration threshold) under the current low-pressure state, after which the vacuum drying unit 340 opens and the substrate 400 is conveyed. In a specific example, the magnitude of the fourth duration threshold can be determined based on the air pressure value during low-pressure drying.

[0090] Furthermore, when executing abnormal strategies, the controller can also be specifically used to: control the reduction of the unwinding speed and adjust the coating parameters of the coating unit 320 accordingly; control the reduction of the winding speed and adjust the drying temperature of the drying unit 360 accordingly; and control the increase of the discharge speed of the first storage unit 330 and the feed speed of the second storage unit 350. Thus, while identifying abnormal air pressure and performing abnormal handling control on the vacuum drying unit 340, it can also achieve matched abnormal handling control on other units of the roll-to-roll device, effectively improving the applicability and reliability of the preparation device for online continuous production.

[0091] Preferably, such as Figure 5 and Figure 6 As shown, the coating unit 320 can coat the substrate continuously or intermittently. In the case of intermittent coating, as... Figure 6 As shown, the intermittently coated substrate 400 includes a coating area 410 and an intermittent area 420. Under low-pressure operation, the substrate area squeezed between the upper housing 341 and the lower housing 342 at least partially corresponds to the intermittent area 420, thereby achieving both improved vacuum drying process efficiency and improved uniformity of the functional film.

[0092] In summary, the roll-to-roll flexible functional layer fabrication apparatus according to the embodiments of this application, by setting up a dedicated first storage unit, a vacuum drying unit, and a second storage unit after the coating unit; by setting up an upper shell, a lower shell, and a vacuum extraction subunit for the vacuum drying unit; and by setting a gap between the upper and lower shells of the vacuum drying unit when a normal pressure working command is received, allowing the coated substrate to be transported, with the first storage unit discharging and the second storage unit feeding; and by stopping the first storage unit from discharging and the second storage unit from feeding when a low pressure working command is received, with the upper and lower shells being squeezed together to define a low-pressure cavity containing a portion of the substrate, and then vacuum drying the substrate in the low-pressure cavity until the next normal pressure working command is received. Therefore, it can meet both the high performance requirements and continuous production requirements for specific flexible functional layers. It is particularly suitable for the continuous production of flexible perovskite functional layers, and the prepared perovskite functional layers have high purity and good crystallization effect, which helps to improve the photoelectric conversion efficiency of perovskite solar cells.

[0093] Figure 7This is a flowchart of a roll-to-roll flexible functional layer fabrication method according to an embodiment of this application. This roll-to-roll flexible functional layer fabrication method employs the roll-to-roll flexible functional layer fabrication apparatus described in the above embodiment, with reference to... Figure 7 As shown, the method for fabricating the roll-to-roll flexible functional layer includes the following steps:

[0094] Step 501: The unwinding unit releases the substrate.

[0095] Step 502: The coating unit coats the substrate, and the first storage unit feeds the coated substrate.

[0096] Step 503: In response to receiving the atmospheric pressure working command, the upper and lower shells of the vacuum drying unit are separated by a gap, the first storage unit discharges material, and the second storage unit feeds material.

[0097] Step 504: In response to receiving the low-pressure working command, the first storage unit stops discharging; the second storage unit stops feeding; the upper shell and the lower shell are squeezed together to define the low-pressure cavity; after vacuuming, the substrate in the low-pressure cavity is vacuum dried.

[0098] Specifically, after evacuation, the substrate in the low-pressure chamber is vacuum dried until the next normal pressure operation command is received.

[0099] Preferably, the vacuum drying unit further includes a temperature control subunit. Step 504 further includes, after vacuuming, or during and after vacuuming, the temperature control subunit controlling the temperature of the low-pressure chamber.

[0100] Step 505: The second storage unit discharges the dried substrate.

[0101] Step 506: The heat drying unit heats the substrate, and the winding unit winds the heat-dried substrate.

[0102] In this embodiment of the application, the roll-to-roll flexible functional layer fabrication apparatus further includes a barometer and a controller. At the controller end, such as... Figure 8 As shown, the method also includes the following steps:

[0103] Step 601: Start the first timing when the vacuuming begins.

[0104] Step 602: Obtain the air pressure value of the low-pressure cavity measured by the barometer.

[0105] Step 603: In response to the air pressure value being equal to the air pressure threshold and the duration of the first timing being less than the first duration threshold, a second timing is initiated, and when the duration of the second timing reaches the second duration threshold, an atmospheric pressure operation command is sent to the vacuum drying unit.

[0106] More preferably, the method further includes the following steps:

[0107] Step 604: In response to the first timing duration reaching the third duration threshold and the air pressure value remaining greater than the air pressure threshold, an air pressure anomaly is determined, and an anomaly strategy is initiated.

[0108] The third duration threshold is greater than the first duration threshold.

[0109] The abnormal strategy includes: performing a third timing, and when the duration of the third timing reaches the fourth duration threshold, sending an atmospheric pressure operation command to the vacuum drying unit.

[0110] Preferably, the abnormal strategy further includes at least one of the following: reducing the unwinding speed and adjusting the coating parameters of the coating unit accordingly; reducing the winding speed and adjusting the drying temperature of the drying unit accordingly; increasing the discharge speed of the first storage unit and the feed speed of the second storage unit.

[0111] It should be noted that the explanation of the roll-to-roll flexible functional layer fabrication apparatus in the above embodiments also applies to the roll-to-roll flexible functional layer fabrication method in the above embodiments, and will not be repeated here.

[0112] It should be understood that although the steps in the flowcharts in the accompanying drawings are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowchart may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0113] It should be noted that the specific values ​​mentioned above are only for illustrating the implementation of this application in detail, and should not be construed as limitations on this application. In other examples, implementation methods, or embodiments, other values ​​may be selected according to this application, and no specific limitations are made here.

[0114] It will be understood by those skilled in the art that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A roll-to-roll flexible functional layer preparation method applied to a roll-to-roll flexible functional layer preparation device, characterized in that, The device comprises a unwinding unit, a coating unit, a first storage unit, a vacuum drying unit, a second storage unit, a heat drying unit and a winding unit arranged in sequence along the substrate transmission direction; The vacuum drying unit comprises an upper housing, a lower housing and a vacuum subunit, and is used to perform vacuum drying on the coated substrate; In response to receiving a normal pressure working instruction, the upper housing and the lower housing of the vacuum drying unit are arranged in a gap, the gap is used for substrate transmission, the first storage unit discharges, and the second storage unit feeds; In response to receiving a low pressure working instruction, the first storage unit stops discharging, the second storage unit stops feeding, the upper housing and the lower housing are arranged in a pressing manner to define a low pressure cavity with the inner part of the substrate, and the substrate in the low pressure cavity is subjected to vacuum drying; The feeding speed of the first storage unit matches the unwinding speed of the unwinding unit, the discharging speed of the first storage unit is greater than the feeding speed, the discharging speed of the second storage unit matches the winding speed of the winding unit, and the feeding speed of the second storage unit is greater than the discharging speed; The device is also provided with a barometer and a controller, and the method further comprises, When the vacuum starts, first timing is performed; The air pressure value of the low pressure cavity measured by the barometer is obtained; In response to the air pressure value being equal to the air pressure threshold value and the first timing being less than the first time threshold value, second timing is performed, and when the second timing reaches the second time threshold value, the normal pressure working instruction is sent to the vacuum drying unit; The method comprises, The unwinding unit unwinds the substrate; The coating unit coats the substrate, and the first storage unit feeds the coated substrate; In response to receiving a normal pressure working instruction, the upper housing and the lower housing of the vacuum drying unit are arranged in a gap, the first storage unit discharges, and the second storage unit feeds; In response to receiving a low pressure working instruction, the first storage unit stops discharging, the second storage unit stops feeding, the upper housing and the lower housing are arranged in a pressing manner to define the low pressure cavity, and the substrate in the low pressure cavity is subjected to vacuum drying after vacuuming; The second storage unit discharges the dried substrate; The heat drying unit performs heat drying on the substrate, and the winding unit winds the heat dried substrate; the unwinding speed of the unwinding unit and / or the winding speed of the winding unit is set to be uniform online; The method further comprises, In response to the first timing reaching a third time threshold value and the air pressure value remaining greater than the air pressure threshold value, it is determined that the air pressure is abnormal, and an abnormal strategy is started; The third time threshold value is greater than the first time threshold value; The abnormal strategy comprises third timing, and when the third timing reaches a fourth time threshold value, the normal pressure working instruction is sent to the vacuum drying unit; The abnormal strategy further includes the following manners: reducing the unwinding speed and matching and adjusting the coating parameters of the coating unit; reducing the winding speed and matching and adjusting the heat baking temperature of the heat baking unit; increasing the discharging speed of the first storage unit and the feeding speed of the second storage unit.

2. The roll-to-roll flexible functional layer manufacturing method according to claim 1, characterized in that, The vacuum pumping subunit comprises a dry pump and a molecular pump; the vacuum pressure maintaining time of the vacuum pumping is 10-20s.

3. The roll-to-roll flexible functional layer fabrication method of claim 1, wherein, The vacuum drying unit further comprises a temperature control subunit for controlling the temperature of the low-pressure cavity.

4. The roll-to-roll flexible functional layer preparation method according to claim 1, characterized in that, The air pressure gauge is used to measure the air pressure value in the low-pressure cavity of the vacuum drying unit; The controller is used to control the working state of the vacuum drying unit based on the air pressure value.

5. The roll-to-roll flexible functional layer fabrication method of claim 1, wherein, The coating of the coating unit on the substrate is configured as continuous coating or intermittent coating; The substrate coated by the intermittent coating comprises a coating area and an intermittent area; in the low-pressure working state, the substrate area squeezed between the upper shell and the lower shell at least partially corresponds to the intermittent area.

6. The roll-to-roll flexible functional layer manufacturing method according to any one of claims 1 to 5, characterized in that, The functional layer is a perovskite functional layer.

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