Method, device and system for controlling pressure field of perovskite wet film vacuum drying

Abstract

This invention relates to the field of perovskite photovoltaic module fabrication, and particularly to a method, apparatus, and system for controlling the pressure field during vacuum drying of perovskite wet films. The method involves acquiring defect information on the surface of a perovskite precursor wet film after vacuum contact drying; determining the flow instability range of the wet film based on the defect type; determining the corresponding parameter adjustment strategy based on a preset defect phase diagram; and synergistically adjusting at least one of the following parameters—pumping rate, pressure drop rate, final pressure, holding time, and the relative distance between the pumping rate and the pumping area distribution—to ensure that the adjusted vacuum contact drying process enters a stable film-forming region. This invention transforms vacuum contact drying from empirical adjustment of a single parameter to feedback control of the pressure field, uniformly suppressing transparent pores, dense pitting, and pumping marks, thereby improving the film-forming stability of large-area wet films.

Description

Technical Field

[0001] This invention relates to the field of perovskite photovoltaic module manufacturing technology, and in particular to a method, apparatus and system for controlling the pressure field of vacuum drying of perovskite wet film. Background Technology

[0002] Perovskite photovoltaic technology, with its excellent photoelectric conversion efficiency, low theoretical preparation cost, and good potential for large-area fabrication, is considered an important development direction for next-generation high-efficiency thin-film photovoltaic technology. In the fabrication of large-area perovskite modules, slot coating has become an important technical route for the preparation of perovskite absorber layers due to its advantages of continuous film formation, high material utilization, good film thickness controllability, and ease of production line scaling. After the perovskite precursor wet film is formed by slot coating, it is usually necessary to quickly remove the solvent through vacuum contact drying to control the transformation of the wet film from a liquid or semi-liquid state to a gel state and then a solid film, and to provide a stable foundation for subsequent annealing and crystallization.

[0003] However, in actual large-area slot coating and vacuum contact drying combined processes, abnormal defects often appear on the film surface, such as dense transparent holes, dense pitting, evacuation marks, arched textures, and wavy patterns. These defects evolve significantly with changes in evacuation distance, evacuation rate, final pressure, and holding time. For example, under certain drying conditions, the film surface exhibits dense transparent holes; when the relative distance between the wet film and the evacuation unit is changed, the transparent holes may decrease or disappear, but dense pitting appears on the film surface; when the local evacuation disturbance is further enhanced, the dense pitting may decrease again, but arc-shaped or arched evacuation marks appear.

[0004] In existing technologies, vacuum contact drying is typically viewed as a simple process of vacuuming and solvent removal, with optimization primarily focused on empirical adjustments of single process parameters such as pumping rate, final pressure, and holding time. However, simply reducing the pumping rate may lead to insufficient solvent removal and locking of the wet film, resulting in vortex-like, flower-like, or flow instability defects; conversely, simply increasing the final pressure may prevent timely fixation of the wet film edge areas, inducing wavy lines or abnormal edge flow. Furthermore, existing technologies lack a systematic understanding of the correspondence between defect types, pressure field conditions, and combinations of process parameters, and also lack a stable film-forming window for production line feedback control. Process debugging can easily fall into a cycle where one defect is suppressed while another reappears.

[0005] Therefore, how to transform the vacuum contact drying process from a traditional empirical vacuuming process into a pressure field control process that is identifiable, judgmentable, feedback-enabled, and controllable, so that the wet film is stably within the film-forming window, thereby systematically suppressing defects such as transparent pores, dense pits, and vacuum marks, has become a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method, apparatus and system for controlling the pressure field of vacuum drying of perovskite wet films, so as to solve the problem that the vacuum contact drying in the prior art relies only on the empirical adjustment of a single process parameter, lacks a unified judgment basis between defect type and pressure field state, resulting in the waxing and waning of film surface defects and poor stability of large-area wet film formation.

[0007] To solve the above technical problems, the present invention provides a method for controlling the pressure field of vacuum drying of perovskite wet films, comprising: Obtain defect information on the surface of the wet perovskite precursor film after vacuum contact drying; Based on the defect type in the defect information, the flow instability zone of the wet film is determined; the flow instability zone includes the pore-dominated zone, the pit-dominated zone, the pump mark-dominated zone, and the stable film-forming zone. The parameter adjustment strategy corresponding to the flow instability range is determined according to the preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, and the vacuum drying parameter combination includes at least one of the following: the relative distance between the wet film and the pumping unit, and the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution. According to the parameter adjustment strategy, at least one of the following parameters, namely the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution, and their relative distance, are adjusted in a coordinated manner so that the vacuum contact drying process after adjustment enters the stable film formation zone.

[0008] Optionally, in the perovskite wet film vacuum drying pressure field control method, the step of synergistically adjusting at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution relative to the relative distance according to the parameter adjustment strategy includes: When the wet film is in the pore-dominant region, reduce the relative distance and adjust the pumping rate or pressure drop rate to enhance the local desolvation uniformity and wet film locking ability. When the wet film is in the predominantly pitted area, the relative distance and the distribution of the extraction area are adjusted to reduce the local pressure gradient and microscale lateral flow. When the wet film is in the area dominated by suction marks, the relative distance is increased and the local suction intensity at the position corresponding to the suction mark is reduced to weaken the local airflow impact and directional shearing. When the wet film is in the stable film-forming region, maintain the current combination of vacuum drying parameters.

[0009] Optionally, in the aforementioned method for controlling the pressure field during vacuum drying of perovskite wet films, the defect phase diagram is pre-established in the following manner: Under the same coating conditions and the same perovskite precursor system, by changing the combination of vacuum drying parameters, the film surface state under different parameter combinations can be obtained. Obtain defect statistics for each membrane surface condition; the defect statistics include at least one of the following: number of transparent holes per unit area, number of pits per unit area, area of ​​wavy region, and spatial correlation between defects and the location of air extraction holes; Based on the aforementioned defect statistics, each combination of vacuum drying parameters is divided into a pore-dominant region, a pit-dominant region, a sampling mark-dominant region, or a stable film-forming region. Using process conditions, including at least two parameters from the vacuum drying parameter combination, as dimensions, a mapping relationship is established between the values ​​of each dimension and the divided film surface states to form the defect phase diagram.

[0010] Optionally, in the perovskite wet film vacuum drying pressure field control method, the pumping area includes multiple partitions, the pumping unit includes partition pumping channels corresponding to the partitions and partition valves that control the pumping intensity of each partition respectively, and the defect information also includes the spatial correlation between defects and the partitions. Accordingly, the step of coordinating the adjustment of at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution relative to the relative distance according to the parameter adjustment strategy includes: When there is a spatial correlation between the sampling mark and one of the partitions, reduce the valve opening of that partition or increase the relative distance; When the holes are concentrated in one of the partitions, the relative distance is reduced, or the air extraction efficiency of that partition is increased.

[0011] Optionally, in the perovskite wet film vacuum drying pressure field control method, a pressure equalization and flow guiding structure is provided between the pumping unit and the wet film. The pressure equalization and flow guiding structure includes at least one of a buffer cavity, a porous pressure equalization plate, a flow guiding layer, and an edge pressure relief groove. Accordingly, the step of coordinating the adjustment of at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution relative to the relative distance according to the parameter adjustment strategy further includes: When the wet film is in the predominant area of ​​pitting, the porous pressure equalizing plate or the flow guiding layer is activated to convert the point-like air extraction of the air extraction unit into surface air extraction. When the wet film is in the area dominated by suction marks, the buffer chamber is activated to weaken the local low-pressure peak near the suction port, or the pressure difference between the edge area and the center area is reduced by the edge pressure relief groove.

[0012] Optionally, in the aforementioned method for controlling the pressure field of vacuum drying of perovskite wet films, the vacuum contact drying is performed sequentially in three stages, including: The first stage is the pre-stabilization and desolvation stage, in which the wet film is evacuated at a first evacuation rate while the relative distance is maintained at a first distance. The second stage is the enhanced desolvation and locking stage, in which the wet film is evacuated at a second evacuation rate greater than the first evacuation rate, or the relative distance is reduced to a second distance less than the first distance. The third stage is the post-stabilization stage, which involves holding the pressure for a preset time after reaching the final pressure.

[0013] Optionally, in the aforementioned method for controlling the pressure field during vacuum drying of perovskite wet films, obtaining defect information on the surface of the perovskite precursor wet film after vacuum contact drying includes: Acquire images of the surface of the wet film; The membrane image is preprocessed; Candidate regions for holes, pits, and scratches are extracted from the preprocessed membrane image; Extract the defect features of the candidate region; the defect features include at least one of the following: defect number, area, equivalent diameter, aspect ratio, roundness, grayscale contrast, texture variance, density per unit area, orientation consistency, arc fitting degree, and spatial correlation between the defect and the evacuation area. Based on the defect characteristics, output the defect category and the defect index vector composed of the defect characteristics.

[0014] Optionally, in the aforementioned method for controlling the pressure field during vacuum drying of perovskite wet films, determining the flow instability range of the wet film based on the defect type in the defect information includes: When the arc fitting degree or directional consistency of the candidate region of the sampling mark exceeds the third threshold, the wet film is determined to be in the sampling mark dominant region. When the arc fitting degree and direction consistency of the candidate region of the burr mark do not exceed the third threshold, and the gray-scale contrast or unit area density of the candidate region of the hole exceeds the first threshold, the wet film is determined to be in the hole-dominant region. When the arc fitting degree and direction consistency of the candidate region of the puncture mark do not exceed the third threshold, and the gray contrast and unit area density of the candidate region of the hole do not exceed the first threshold, and the unit area density or texture variance of the candidate region of the pit exceeds the second threshold, the wet film is determined to be in the pit-dominant region. When the arc fitting degree and direction consistency of the candidate region for the burr mark, the grayscale contrast and unit area density of the candidate region for the hole, and the unit area density and texture variance of the candidate region for the pit do not exceed the corresponding thresholds, the wet film is determined to be in the stable film formation region.

[0015] A pressure field control device for vacuum drying of perovskite wet film includes: The data acquisition module is used to acquire defect information on the surface of the perovskite precursor wet film after vacuum contact drying. The interval identification module is used to determine the flow instability interval of the wet film based on the defect type in the defect information; the flow instability interval includes the pore-dominated region, the pit-dominated region, the pump mark-dominated region, and the stable film-forming region; The strategy determination module is used to determine the parameter adjustment strategy corresponding to the flow instability range based on the preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, and the vacuum drying parameter combination includes at least the relative distance between the wet film and the pumping unit, and at least one of the following: pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution. The adjustment module is used to coordinately adjust at least one of the following parameters and relative distances according to the parameter adjustment strategy: the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution, so that the vacuum contact drying process after adjustment enters the stable film formation zone.

[0016] A pressure field control system for vacuum drying of perovskite wet films includes: A substrate support assembly for supporting a substrate on which a perovskite wet film has been formed; An air extraction assembly is disposed above the wet film and includes partitioned air extraction channels and partitioned valves that control the air extraction intensity of each partition respectively. A pressure equalization and flow guiding component is disposed between the air extraction component and the wet film, and includes a buffer chamber, a porous pressure equalization plate and a flow guiding layer arranged sequentially from top to bottom; The gap adjustment assembly includes a drive mechanism and a displacement detection mechanism. The drive mechanism is used to drive the air extraction assembly, the pressure equalization and flow guiding assembly, or the substrate support assembly to rise and fall to change the relative distance between the wet film and the air extraction assembly. The displacement detection mechanism is used to provide feedback on the relative distance. Detection components are used to acquire membrane surface images and / or pressure information; A control component is used to control the gap adjustment component, the air extraction component, and the partition valve according to the defect type reflected by the membrane image and based on a defect phase diagram; the defect phase diagram characterizes the mapping relationship between the flow instability range of the membrane surface and the combination of vacuum drying parameters.

[0017] The perovskite wet film vacuum drying pressure field control method provided by this invention obtains defect information on the surface of the perovskite precursor wet film after vacuum contact drying; determines the flow instability zone of the wet film based on the defect type in the defect information; the flow instability zone includes a pore-dominated zone, a pit-dominated zone, a suction mark-dominated zone, and a stable film-forming zone; determines the parameter adjustment strategy corresponding to the flow instability zone based on a preset defect phase diagram; the defect phase diagram characterizes the mapping relationship between the flow instability zone and the vacuum drying parameter combination, the vacuum drying parameter combination including at least the relative distance between the wet film and the pumping unit, and at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution; according to the parameter adjustment strategy, at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution, along with the relative distance, are synergistically adjusted so that the vacuum contact drying process after adjustment enters the stable film-forming zone.

[0018] This invention attributes transparent holes, dense pits, and suction marks to the continuous evolution of flow instability in large-area wet films under the non-uniform pressure field of vacuum contact drying. It constructs a defect phase diagram with four types of flow instability zones: hole-dominated zone, pit-dominated zone, suction mark-dominated zone, and stable film-forming zone. This allows the morphology of film defects to become a basis for inversely judging the flow state of the wet film, avoiding the problem in traditional processes where adjusting a single parameter based on a single defect leads to the reduction of one defect while the increase of another. This achieves unified suppression of multiple types of drying-induced defects. Furthermore, this invention uses the relative distance and suction rate... The synergistic adjustment of at least one of the following parameters—pressure drop rate, final pressure, holding time, and evacuation area distribution—replaces empirical adjustment of a single parameter. This transforms vacuum contact drying from a simple vacuuming and solvent removal process into a pressure field control process that is identifiable, predictable, feedback-enabled, and controllable. This reduces the lateral pressure gradient and local solvent evaporation imbalance on the wet film surface, improves film continuity and uniformity, and allows drying parameters for different solution systems, substrate states, film thicknesses, and equipment conditions to be adjusted through feedback to reach a stable film formation region. This expands the process window tolerance and improves production line adaptability and yield. The present invention also provides a pressure field control device and system for vacuum drying perovskite wet films with the above-mentioned beneficial effects. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of 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.

[0020] Figure 1This is a schematic diagram illustrating the evolution of film surface defects described in this invention. Figure 2 A flowchart illustrating a specific embodiment of the pressure field control method for vacuum drying of perovskite wet film provided by the present invention; Figure 3 This is a microscopic view of the dense pitting defect described in this invention; Figure 4 A comparison of device performance under different vacuum drying parameter control conditions in a specific embodiment of the pressure field control method for vacuum drying of perovskite wet film provided by the present invention; Figure 5 A schematic diagram of a specific embodiment of the pressure field control system for vacuum drying of perovskite wet film provided by the present invention; Figure 6 This is a schematic diagram of a specific embodiment of the pressure field regulation and control device for vacuum drying of perovskite wet film provided by the present invention.

[0021] Figure label: 100-Data Acquisition Module; 200-Interval Identification Module; 300-Strategy Determination Module; 400-Adjustment Module; 1-Baseboard Support Assembly; 2-Air Extraction Assembly; 21-Zoned Air Extraction Channel; 22-Zoned Valve; 3-Pressure Equalization and Flow Guiding Assembly; 31-Buffer Chamber; 32-Porous Pressure Equalization Plate; 33-Flow Guiding Layer; 4-Gap Adjustment Assembly; 41-Drive Mechanism; 42-Displacement Detection Mechanism; 5-Detection Assembly; 6-Control Assembly. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] The core of this invention lies not in setting a single process parameter, but in identifying the flow state of the wet film during vacuum contact drying by analyzing the morphology of film surface defects, and then using a defect phase diagram to feedback-regulate the pressure field, ensuring the wet film remains within a stable film-forming window. A schematic flowchart of a specific embodiment of the pressure field regulation method for vacuum drying of perovskite wet films provided by this invention is shown below. Figure 2 As shown, this is referred to as Specific Implementation Method One, which includes: S101: Obtain defect information on the surface of the perovskite precursor wet film after vacuum contact drying.

[0024] The perovskite precursor wet film is formed on the surface of a transparent conductive substrate or a substrate with a pre-deposited functional layer using a slot coating method. The substrate includes, but is not limited to, glass / FTO substrates, glass / ITO substrates, and glass / FTO / NiO substrates. x Substrate, glass / ITO / NiO x The substrate or other conductive substrate suitable for pin-type perovskite photovoltaic modules; the perovskite precursor wet film may be a perovskite precursor system containing components such as cesium, formamidinium, methylamine, lead, iodine, and bromine, and its solvent includes, but is not limited to, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, or combinations thereof. The wet film after slot coating is transported to a vacuum contact drying device within a preset time. The specific structure of the vacuum contact drying device can be found in the following description. Figure 5 The description.

[0025] In this step, the defect information on the film surface can be obtained either after the wet film has undergone vacuum contact drying or during the vacuum contact drying process. The defect information obtained in the former case is used to adjust the vacuum drying parameters of the subsequent wet film to be dried, while the defect information obtained in the latter case is used to adjust the vacuum drying parameters of the current wet film in the remaining drying stage. Both methods can enable the vacuum contact drying process after adjustment to enter the stable film-forming region, and this invention does not limit the specific method used.

[0026] The defect information of the membrane surface can be obtained through an image acquisition module, a visual inspection module, a microscopic inspection module, an EL inspection module, a reflected light detection module, or a grayscale analysis module. It includes, but is not limited to, the number of transparent holes, the area ratio of transparent holes, the number of pits, the density of pits, the width of the wavy area, the location of the defect distribution, and the spatial correspondence between the defects and the air extraction holes or air extraction areas.

[0027] In this step, drying process information can also be obtained simultaneously through the pressure detection module, flow detection module, or control system log. The drying process information includes, but is not limited to: pumping speed Q, pressure drop rate dP / dt, final pressure P, holding time T, relative distance H between the wet film and the pumping unit, substrate dwell time, and waiting time before the wet film enters the vacuum contact drying device, so as to form state points in the defect phase diagram together with the defect information of the film surface.

[0028] It should be noted that the relative distance H mentioned in this invention refers to the vertical distance between the upper surface of the perovskite wet film and the effective suction surface of the upper suction unit, or, when a pressure equalization and flow guiding structure is provided, the vertical distance between the upper surface of the wet film and the lower surface of the pressure equalization and flow guiding structure. The relative distance H is used to change the local pressure gradient and suction shear strength experienced by the wet film, and is not limited to the distance defined by a fixed top PIN structure.

[0029] In a preferred embodiment, this step includes: A1: Acquire an image of the wet film surface.

[0030] The sources of the film surface images include one or more of the following: vacuum contact dried reflected light surface scan images, microscopic images, dark field images, EL images, or line scan images. During acquisition, the acquisition position, exposure parameters, resolution, and illumination angle can be recorded simultaneously to ensure comparability between images from different batches.

[0031] A2: Preprocess the membrane image.

[0032] The preprocessing includes one or more of the following: effective region cropping, background subtraction, flat field correction, grayscale normalization, median filtering, or Gaussian filtering, to reduce the impact of uneven illumination and random noise on defect judgment.

[0033] A3: Extract candidate regions for holes, pits, and scratches from the preprocessed membrane image.

[0034] This step can employ one or more of the following methods: global thresholding, local adaptive thresholding, edge detection, binarization, opening / closing operations, and connected component labeling, to obtain candidate regions for suspected holes, pits, nicks, and wavy lines. For example, thresholding and connected component analysis can be used to extract bright, transparent areas as candidate regions for transparent holes; local texture variance and small-size connected component density can be used to extract dense pit candidate regions; and edge detection, Hough transform, or curve fitting methods can be used to identify arc-shaped, arched, or strip-shaped nick candidate regions.

[0035] A4: Extract the defect features of the candidate region.

[0036] The defect features include at least one of the following: defect number N, area A, equivalent diameter D, aspect ratio R, roundness C, grayscale contrast G, texture variance V, density per unit area ρ, orientation consistency O, arc fitting degree F, and spatial correlation S between the defect and the venting hole or venting area.

[0037] A5: Output the defect category and the defect index vector composed of the defect features based on the defect features.

[0038] The defect index vector is used for defect phase diagram determination in subsequent steps.

[0039] It should be noted that the above defect identification process can be implemented using existing machine vision recognition methods, such as grayscale thresholding based on industrial cameras or microscopic images, edge detection, morphological processing, connected component analysis, texture feature analysis, and rule classification algorithms. Alternatively, existing supervised classification models such as support vector machines, random forests, and convolutional neural networks can be introduced based on these features. These are conventional techniques in the field of image processing, and will not be elaborated upon further here. The key improvement of this invention lies in establishing a correspondence between the identified defect morphology and the pressure field state, relative distance, pumping rate, pressure drop rate, final pressure, and holding time during the vacuum drying process. Based on this, adjustment commands are output, so that the film surface image is no longer merely a basis for manual observation, but becomes a feedback input for controlling the vacuum drying parameters.

[0040] S102: Determine the flow instability zone of the wet film based on the defect type in the defect information; the flow instability zone includes the pore-dominated zone, the pit-dominated zone, the sampling mark-dominated zone, and the stable film-forming zone.

[0041] Among them, the pore-dominant region is the area on the membrane surface with many transparent pores or localized dehydration defects, indicating uneven local desolvation of the wet membrane, insufficient pressure field locking, or localized liquid deficiency at the interface; the pitting-dominant region is the area on the membrane surface with dense pits, mottled micro-defects, or localized gray-scale anomalies, indicating that the wet membrane is in a state of microscale flow instability or localized nucleation and locking. A microscopic view of one type of dense pitting defect is shown below. Figure 3 As shown, the flow mark-dominant zone is the area on the film surface where there are arched, arc-shaped, wavy, or flow marks distributed along the air extraction path, indicating that the local airflow disturbance or lateral shear is too strong; the stable film-forming zone is the area on the film surface where there are no obvious transparent holes, no dense pits, no continuous air extraction marks, and the number of defects, area ratio, and grayscale fluctuation are all lower than the preset threshold.

[0042] The above classification of the four types of flow instability zones is based on the understanding that transparent holes, dense pitting, and evacuation marks are not entirely independent defects, but rather the continuous evolution of a large-area wet film under the non-uniform pressure field of vacuum contact drying, resulting in varying degrees of flow instability, solvent evaporation imbalance, and localized premature solidification. A schematic diagram of their evolutionary relationship is shown below. Figure 1As shown, during the actual large-area perovskite wet film vacuum contact drying process, it can be observed that: when the relative distance between the wet film and the pumping unit is large, dense transparent holes easily appear on the film surface; when the height of the top pin is adjusted to bring the wet film closer to the upper pumping structure, the dense transparent holes disappear, but dense pitting appears on the film surface; after further increasing the height of the top pin, the dense pitting decreases; when it is further increased to a position with strong airflow disturbance, arched or arc-shaped pumping marks appear on the film surface, while the pitting basically disappears. The above results indicate that there is a clear evolutionary relationship between transparent holes, dense pitting, and pumping marks, and this evolutionary relationship is affected by the geometric conditions of vacuum contact drying and the pumping pressure field. Therefore, the flow instability range of the wet film can be inversely determined from the morphology of the film surface defects.

[0043] Furthermore, this step includes: When the arc fitting degree or directional consistency of the candidate region of the sampling mark exceeds the third threshold, the wet film is determined to be in the sampling mark dominant region. When the arc fitting degree and direction consistency of the candidate region of the burr mark do not exceed the third threshold, and the gray-scale contrast or unit area density of the candidate region of the hole exceeds the first threshold, the wet film is determined to be in the hole-dominant region. When the arc fitting degree and direction consistency of the candidate region of the puncture mark do not exceed the third threshold, and the gray contrast and unit area density of the candidate region of the hole do not exceed the first threshold, and the unit area density or texture variance of the candidate region of the pit exceeds the second threshold, the wet film is determined to be in the pit-dominant region. When the arc fitting degree and direction consistency of the candidate region for the burr mark, the grayscale contrast and unit area density of the candidate region for the hole, and the unit area density and texture variance of the candidate region for the pit do not exceed the corresponding thresholds, the wet film is determined to be in the stable film formation region.

[0044] The above judgment order is a rule priority classification, that is, the area dominated by suction marks is judged first, followed by the area dominated by holes, then the area dominated by pitting, and finally the stable film-forming area, in order to avoid judgment conflicts when multiple criteria are met simultaneously. Among them, transparent hole defects are characterized by brightness or light transmittance significantly higher than the surrounding area, relatively clear boundaries, and may be circular or irregularly island-shaped. The criteria may include grayscale contrast G greater than the first threshold, connected region area A within the first area range, and hole density greater than the preset threshold; dense pitting defects are characterized by low contrast, high density, discrete or mottled micro-defects. The criteria may include the number of defects per unit area greater than the second threshold, small equivalent diameter of a single point, texture variance V greater than the preset value, and no obvious uniform direction; suction marks or wavy texture defects are characterized by continuous arc-shaped, strip-shaped, or textured along the suction path. The criteria may include aspect ratio R greater than the fourth threshold, arc fitting degree F or directional consistency O greater than the preset value, and spatial correlation S with the suction hole array, suction port, or edge area.

[0045] This preferred embodiment defines the priority order of defect type determination, ensuring a definite selection relationship when various criteria are simultaneously met, thus avoiding ambiguity in the determination results. As another specific embodiment, this step can also employ a scoring classification method, that is, calculating the pore score Sh, pitting score Sm, dent score Sa, and stability score Ss respectively, and using the category corresponding to the highest score as the current flow instability range of the membrane surface.

[0046] It should be noted that the first threshold, second threshold and third threshold mentioned above are not limited to fixed values. They can be obtained by calibration of historical samples based on historical batches, substrate type, wet film thickness, formulation system and detection resolution, or can be automatically updated by production line experience values ​​or statistical distribution. This invention does not limit these values.

[0047] S103: Determine the parameter adjustment strategy corresponding to the flow instability range according to the preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, the vacuum drying parameter combination includes at least the relative distance between the wet film and the pumping unit, and at least one of the following: pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution.

[0048] Before this step, the defect phase diagram needs to be established in advance. As a preferred embodiment, the defect phase diagram is established in the following manner: B1: Under the same coating conditions and the same perovskite precursor system, the combination of vacuum drying parameters is changed to obtain the film surface state under different parameter combinations.

[0049] Specifically, under the same slit coating conditions and the same perovskite precursor system, one or more of the relative distance H, pumping speed Q, final pressure P, and holding time T can be changed to obtain the film surface state under different vacuum drying conditions.

[0050] B2: Obtain defect statistics for each membrane surface condition; the defect statistics include at least one of the following: number of transparent holes per unit area, number of pits per unit area, area of ​​wavy region, and spatial correlation between defects and the location of air extraction holes.

[0051] After each set of experiments, images of the membrane surface were acquired and defects were statistically analyzed. The methods for image acquisition and defect statistics can be referred to the descriptions of A1 to A5 in step S101, and will not be repeated here.

[0052] B3: Based on the aforementioned defect statistics, each combination of vacuum drying parameters is divided into the pore-dominant zone, pit-dominant zone, extraction-mark-dominant zone, or stable film-forming zone.

[0053] B4: Using process conditions, including at least two parameters from the vacuum drying parameter combination, as dimensions, establish a mapping relationship between the values ​​of each dimension and the divided film surface states to form the defect phase diagram.

[0054] In a preferred embodiment, the defect phase diagram is represented in a two-dimensional form, for example, with the relative distance H as the horizontal axis and the pumping rate Q or pressure drop rate dP / dt as the vertical axis, marking the pore-dominant region, pitting-dominant region, pumping mark-dominant region, and stable film-forming region on the coordinate plane. In another preferred embodiment, the defect phase diagram is represented in a multi-dimensional database form, that is, the relative distance H, pumping rate Q, final pressure P, holding time T, pressure drop rate dP / dt, substrate type, wet film thickness, and formulation information are used as input parameters, and the film surface defect state is used as the output result. Since both of the above representation forms are based on several process conditions as dimensions and establish a correspondence between values ​​and film surface states within the parameter space spanned by these dimensions, they both fall within the scope of the defect phase diagram described in this invention.

[0055] S104: According to the parameter adjustment strategy, at least one of the pumping speed, pressure drop rate, final pressure, holding time and pumping area distribution is adjusted in a coordinated manner with the relative distance, so that the vacuum contact drying process after adjustment enters the stable film formation zone.

[0056] In a preferred embodiment, this step includes: When the wet film is in the pore-dominant region, reduce the relative distance and adjust the pumping rate or pressure drop rate to enhance the local desolvation uniformity and wet film locking ability. When the wet film is in the predominantly pitted area, the relative distance and the distribution of the extraction area are adjusted to reduce the local pressure gradient and microscale lateral flow. When the wet film is in the area dominated by suction marks, the relative distance is increased and the local suction intensity at the position corresponding to the suction mark is reduced to weaken the local airflow impact and directional shearing. When the wet film is in the stable film-forming region, maintain the current combination of vacuum drying parameters.

[0057] Specifically, when the detection system detects dense transparent pores on the membrane surface, the control system determines that the current process is in the pore-dominated zone. At this time, the effective pumping distance between the wet membrane and the pumping unit can be reduced, the pressure drop rate dP / dt can be optimized, and the start-stop sequence of zoned pumping can be adjusted to make the low-pressure distribution more uniform, thereby improving the local desolvation uniformity. When the detection system detects dense pitting on the membrane surface, the control system determines that the current process is in the pitting-dominated zone. At this time, the relative distance can be adjusted to reduce the pressure gradient on the wet membrane surface, the pressure equalization and flow guiding structure can be activated, and the pumping intensity in local areas of the pumping hole array can be adjusted, thereby reducing the pumping unit's pressure. Local shear differences between elements; when the detection system detects arched, arc-shaped, or wavy suction marks on the membrane surface, the control system determines that the current process is in the suction mark-dominant zone. At this time, the relative distance between the wet membrane and the suction unit can be increased, the local suction rate can be reduced, the pressure drop rate can be reduced, and a buffer chamber or a porous pressure equalizing plate can be activated to reduce the pressure difference between the edge area and the center area; when the detection system detects that there are no obvious holes, pits, or suction marks on the membrane surface, and the defect statistics are all below the preset threshold, the control system determines that the current process is in the stable film formation zone, and can store the current parameter combination as the optimal process window.

[0058] In this preferred embodiment, since at least one of the relative distance and pumping rate, pressure drop rate, final pressure, holding time and pumping area distribution is adjusted simultaneously, the insufficient wet film desolvation and locking caused by reducing the pumping rate alone is avoided, as is the failure of the wet film edge area to be fixed in time caused by increasing the final pressure alone. Thus, the problem that single parameter optimization is difficult to take into account multiple defects is fundamentally solved. Figure 4 The performance comparison of the device under different vacuum drying parameter control conditions is shown. It can be seen that after the above feedback control, the film surface defects are suppressed and the performance of the corresponding device is improved.

[0059] Furthermore, the extraction area may include multiple partitions, and the extraction unit includes partition extraction channels corresponding to the partitions and partition valves that control the extraction intensity of each partition. The defect information also includes the spatial correlation between the defect and the partition. Accordingly, this step includes: When there is a spatial correlation between the sampling mark and one of the partitions, reduce the valve opening of that partition or increase the relative distance; When the holes are concentrated in one of the partitions, the relative distance is reduced, or the air extraction efficiency of that partition is increased.

[0060] Specifically, the partitions may include a central region, an edge region, an inlet region, and an outlet region. The pumping intensity of each region is controlled by partition valves to compensate for pressure field differences in different areas of the large-area substrate. For example, when pumping marks are highly correlated with the location of a certain pumping port, it indicates that the pumping intensity of that region is too high. The control unit can reduce the opening of the valve in that region or increase the relative distance. When pores are concentrated in a certain region and the desolvation in that region is insufficient, the control unit can appropriately reduce the relative distance or increase the pumping efficiency of that region. In this preferred embodiment, a correspondence is established between the distribution location of defects on the film surface and the location of the pumping partitions, refining parameter adjustment from overall adjustment to in-plane directional compensation, thereby eliminating local defects without sacrificing the desolvation efficiency of other regions.

[0061] Based on the above preferred embodiments, a pressure equalization and flow guiding structure can also be provided between the air extraction unit and the wet film. The pressure equalization and flow guiding structure includes at least one of a buffer cavity, a porous pressure equalization plate, a flow guiding layer, and an edge pressure relief groove. Accordingly, this step also includes: When the wet film is in the predominant area of ​​pitting, the porous pressure equalizing plate or the flow guiding layer is activated to convert the point-like air extraction of the air extraction unit into surface air extraction. When the wet film is in the area dominated by suction marks, the buffer chamber is activated to weaken the local low-pressure peak near the suction port, or the pressure difference between the edge area and the center area is reduced by the edge pressure relief groove.

[0062] The pressure equalization and flow guiding structure is used to convert the local suction effect generated by the vacuum pump into a relatively uniform in-plane pressure field. In addition to the aforementioned buffer chamber, porous pressure equalization plate, flow guiding layer, and edge pressure relief groove, it may also include one or more of the following: a metal mesh plate, a microporous plate, a zoned gas extraction channel, and a zoned valve. The flow guiding layer can be a honeycomb flow guiding plate or a slit flow guiding plate, used to limit abrupt changes in lateral airflow. In this preferred embodiment, the pressure equalization and flow guiding structure is used in conjunction with the adjustment of the relative distance: when the membrane surface is identified as a pore-dominated area, the relative distance can be appropriately reduced or the zoned gas extraction optimized to enhance effective desolvation; when the membrane surface is identified as a pitted area, the local pressure gradient can be reduced by fine-tuning the relative distance, activating the pressure equalization and flow guiding plate, or adjusting the zoned valves; when the membrane surface is identified as a suction mark-dominated area, the relative distance can be increased, the gas extraction intensity of the corresponding zone reduced, or the pressure equalization effect of the buffer chamber and porous pressure equalization plate increased to weaken local airflow impact and directional shearing.

[0063] In addition to the aforementioned adjustments to parameter values, the timing sequence of the vacuum contact drying process itself can also be limited. As a preferred embodiment, the vacuum contact drying is performed sequentially in three stages, including: C1: The first stage is the pre-stabilization and desolvation stage, in which the wet film is evacuated at a first evacuation rate, and the relative distance is maintained at a first distance.

[0064] This stage begins when the wet film enters the vacuum contact drying device and continues until the viscosity of the wet film begins to rise significantly. Since the wet film still has strong fluidity at this time, the control objective is to avoid large-scale lateral flow and localized lean liquid. It is preferable to use a gentler pumping rate, a gentler pressure drop rate, and a more uniform pressure field distribution.

[0065] C2: The second stage is the enhanced desolvation and locking stage, in which the wet film is evacuated at a second evacuation rate greater than the first evacuation rate, or the relative distance is reduced to a second distance less than the first distance.

[0066] During this stage, the wet film gradually enters a semi-gelled or semi-solidified state. The control objective is to improve the desolvation efficiency and enable the wet film to lock in quickly. Therefore, it is preferable to appropriately enhance the pumping intensity or reduce the relative distance.

[0067] C3: The third stage is the post-stabilization stage, which involves holding the pressure for a preset time after the final pressure is reached.

[0068] This stage is used to maintain a certain time near or after the final pressure to allow the residual solvent to continue to be removed evenly, while avoiding excessive local disturbances that could cause suction marks or wavy lines.

[0069] By using the above three-stage control, problems such as early flow instability or late-stage localized pumping marks caused by using a single pumping procedure throughout the entire process can be avoided.

[0070] After vacuum contact drying is completed, the substrate can be sent to an annealing equipment for pre-annealing and secondary annealing, so that the perovskite wet film can be crystallized and a large-area perovskite light absorption layer with suppressed defects can be formed.

[0071] Based on Specific Implementation Method 1, and further combined with the whole-cell fabrication process of large-area perovskite photovoltaic modules, Specific Implementation Method 2 is obtained, which includes: providing a glass / FTO / NiOx substrate, wherein the glass serves as a transparent supporting substrate, the FTO serves as a transparent conductive electrode, and the NiOx serves as a hole transport layer or a bottom interface functional layer; cleaning and surface treating the substrate, wherein the cleaning method may include one or more of deionized water cleaning, active cleaning agent cleaning, acetone cleaning, isopropanol cleaning, infrared drying, and plasma treatment; and preparing a perovskite precursor solution, wherein the perovskite precursor solution may contain... The precursor salts include FAI, PbI2, PbBr2, and CsI, and the solvent can be one or more of DMF, NMP, and DMSO. A large-area perovskite precursor wet film is formed on the substrate surface using a slit coating method. The slit-coated wet film is then transported to a vacuum contact drying device and vacuum dried according to steps S101 to S104 above. The treated film is then sent to an annealing device for pre-annealing and secondary annealing to form a perovskite light-absorbing layer. A C60 electron transport layer, a BCP buffer layer, and a composite back electrode are sequentially prepared on the perovskite layer to form a perovskite photovoltaic module.

[0072] It should be noted that this invention is applicable to various perovskite photovoltaic module structures, including but not limited to pin-type perovskite module structures employing other hole transport layers, electron transport layers, or composite back electrodes; this invention is also applicable to large-area substrates of different sizes, including but not limited to 100cm². 2 Components or pilot pieces with specifications such as above, 300mm×300mm, 600mm×600mm, and 1.2m×0.6m.

[0073] The pressure field control device for vacuum drying of perovskite wet film provided by the present invention is described below. A schematic diagram of one specific embodiment is shown below. Figure 6 As shown, it includes: The data acquisition module 100 is used to acquire defect information on the surface of the perovskite precursor wet film after vacuum contact drying. The interval identification module 200 is used to determine the flow instability interval of the wet film based on the defect type in the defect information; the flow instability interval includes a pore-dominated region, a pit-dominated region, a suction mark-dominated region, and a stable film-forming region; The strategy determination module 300 is used to determine the parameter adjustment strategy corresponding to the flow instability range based on a preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, and the vacuum drying parameter combination includes at least one of the following: the relative distance between the wet film and the pumping unit, and the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution. The adjustment module 400 is used to coordinately adjust at least one of the pumping rate, pressure drop rate, final pressure, holding time and pumping area distribution and relative distance according to the parameter adjustment strategy, so that the vacuum contact drying process after adjustment enters the stable film formation zone.

[0074] The data acquisition module 100 may include an image acquisition unit, a pressure detection unit, a flow detection unit, and a displacement detection unit, used to acquire membrane surface images, pressure, flow rate, and displacement, respectively. The interval recognition module 200 may further include a defect recognition unit and a defect classification unit. The defect recognition unit identifies transparent holes, dense pits, suction marks, and wavy lines based on image grayscale, texture, edge features, and spatial distribution features. The defect classification unit divides the membrane surface state into a hole-dominated area, a pit-dominated area, a suction mark-dominated area, or a stable film-forming area. The strategy determination module 300 may include a defect phase diagram database for storing the mapping relationship between defect types and vacuum drying parameter combinations, and for use in parameter decision-making. The adjustment module 400 can execute the determined parameter adjustment strategy by controlling the gap adjustment component, the suction valve, the vacuum pump, and the pressure equalization and flow guiding structure.

[0075] Furthermore, the control device also includes a historical data update module, which stores each combination of vacuum drying parameters and the corresponding film surface results, and updates the stable film formation window in the defect phase diagram accordingly. This allows stable film formation windows for different batches, different formulations, and different equipment conditions to be recorded and reused, thereby transforming experience-based debugging into data-driven control and reducing human judgment errors and repeated trial and error.

[0076] In this preferred embodiment, the control device may employ the following feedback logic: If the pore density is greater than the first threshold, the first adjustment command is output; if the area ratio of pits is greater than the second threshold, the second adjustment command is output; if the arc fitting degree and direction consistency of the sampling marks are greater than the third threshold, the third adjustment command is output; if all defect indicators are lower than the corresponding threshold, the current parameter is recorded as a stable parameter.

[0077] The pressure field control device for vacuum drying of perovskite wet film in this embodiment is used to implement the aforementioned pressure field control method for vacuum drying of perovskite wet film. Therefore, the specific implementation of the control device can be found in the embodiment section of the method above. For example, the data acquisition module 100, the interval identification module 200, the strategy determination module 300, and the adjustment module 400 are used to implement steps S101, S102, S103, and S104 in the above method, respectively. Therefore, the specific implementation can be referred to the description of the corresponding embodiments, which will not be repeated here.

[0078] The pressure field control system for vacuum drying of perovskite wet film provided by the present invention is described below. A schematic diagram of one specific embodiment is shown below. Figure 5 As shown, it includes: Substrate support assembly 1 is used to support a substrate on which a perovskite wet film is formed; The air extraction assembly 2 is disposed above the wet film and includes a partitioned air extraction channel 21 and partitioned valves 22 that control the air extraction intensity of each partition respectively. The pressure equalization and flow guiding component 3 is disposed between the air extraction component 2 and the wet film, and includes a buffer cavity 31, a porous pressure equalization plate 32 and a flow guiding layer 33 arranged sequentially from top to bottom; The gap adjustment component 4 includes a drive mechanism 41 and a displacement detection mechanism 42. The drive mechanism 41 is used to drive the air extraction component 2, the pressure equalization and flow guiding component 3, or the substrate support component 1 to rise and fall to change the relative distance between the wet film and the air extraction component 2. The displacement detection mechanism 42 is used to provide feedback on the relative distance. Detection component 5 is used to acquire membrane surface images and / or pressure information; Control component 6 is used to control the gap adjustment component 4, the air extraction component 2, and the partition valve 22 according to the defect type reflected by the membrane image and based on the defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range of the membrane surface and the combination of vacuum drying parameters.

[0079] The substrate support assembly 1 supports the glass substrate and its large-area perovskite wet film. The air extraction assembly 2 is connected to a vacuum pump to generate the negative pressure environment required for vacuum contact drying. Its partitioned air extraction channels 21 and partitioned valves 22 can control the air extraction intensity of the central area, edge area, inlet area, and outlet area, respectively. The buffer chamber 31 in the pressure equalization and flow guiding assembly 3 is connected to multiple air extraction ports to reduce the local low pressure peak caused by a single air extraction port. The porous pressure equalization plate 32 is provided with regularly or irregularly distributed micropores to convert point air extraction into area air extraction. The flow guiding layer 33 can be a honeycomb flow guiding layer or a slit flow guiding layer to suppress abrupt changes in lateral airflow and make the airflow tend to be uniform before entering the space above the wet film. In addition, the pressure equalization and flow guiding assembly 3 can also be provided with edge pressure relief grooves to reduce the pressure difference between the edge area and the central area.

[0080] In a preferred embodiment, the gap adjustment component 4 can adopt a four-corner synchronous lifting structure or a central four-corner auxiliary support structure. The four-corner synchronous lifting structure includes four sets of lifting guide rails and four sets of servo lead screws or cylinders. The control component 6 synchronously adjusts the height of the four corners according to the feedback from the displacement detection mechanism 42 to maintain the parallelism between the upper air extraction structure and the substrate surface. The central four-corner auxiliary support structure includes a central main drive mechanism and four-corner fine-tuning mechanisms to simultaneously achieve overall lifting and local leveling correction. A top PIN structure or lifting support column can be used as an implementation of the gap adjustment component 4. It is set at the air extraction component 2, the pressure equalization and flow guiding component 3, or the substrate support component 1 to support or limit displacement, so that the air extraction surface maintains a preset gap relative to the wet film surface.

[0081] Furthermore, the gap adjustment component 4 may also include a guiding mechanism and a limiting mechanism. The guiding mechanism may employ a linear guide rail, a slider, a guide column, or a parallel four-bar linkage to ensure the parallelism of the suction component 2 during its lifting and lowering process; the limiting mechanism is used to prevent the suction component 2 from contacting the wet film or substrate. The driving mechanism 41 may employ a servo screw, a stepper motor, a cylinder, an electric cylinder, a wedge mechanism, or a manual fine-tuning mechanism; the displacement detection mechanism 42 may employ a grating ruler, a displacement sensor, an encoder, or a mechanical dial indicator to provide feedback on the relative distance.

[0082] During use, the control component 6 first sets the initial relative distance and evacuation program based on the substrate size and wet film state; then, it starts the vacuum pump and dries the film according to the preset pressure drop curve; after detecting defects on the film surface, the system determines whether to adjust the relative distance, pressure equalization and flow guiding state, or zoned evacuation intensity based on the defect phase diagram. For example, when the evacuation marks are highly correlated with the location of a certain evacuation port, the control component 6 can reduce the opening of the zone valve 22 or increase the relative distance; when the pores are concentrated and desolvation is insufficient, the relative distance can be appropriately reduced or the evacuation efficiency of the corresponding area can be increased; when the pit density is high, the pressure equalization and flow guiding component 3 can be activated or the relative distance can be adjusted to reduce the in-plane pressure gradient.

[0083] The gap adjustment component 4, the air extraction component 2, the pressure equalization and flow guiding component 3, and the control component 6 in the perovskite wet film vacuum drying pressure field control device provided by the present invention can all be integrated into existing vacuum contact drying equipment or newly added vacuum contact drying modules, and are suitable for continuous production lines of large-area perovskite modules, with good industrialization adaptability.

[0084] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the control systems and apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to in the method section.

[0085] It should be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0087] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0088] The above provides a detailed description of the pressure field control method, apparatus, and system for vacuum drying of perovskite wet films provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of this invention.

Claims

1. A method for controlling the pressure field during vacuum drying of perovskite wet films, characterized in that, include: Obtain defect information on the surface of the wet perovskite precursor film after vacuum contact drying; Based on the defect type in the defect information, determine the flow instability range of the wet film; The flow instability zone includes a pore-dominated zone, a pitted zone, a suction mark-dominated zone, and a stable film-forming zone. The parameter adjustment strategy corresponding to the flow instability range is determined according to the preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, and the vacuum drying parameter combination includes at least one of the following: the relative distance between the wet film and the pumping unit, and the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution. According to the parameter adjustment strategy, at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution is adjusted in a coordinated manner with the relative distance, so that the vacuum contact drying process after adjustment enters the stable film formation zone.

2. The method for controlling the pressure field of vacuum drying of perovskite wet film as described in claim 1, characterized in that, According to the parameter adjustment strategy, at least one of the following parameters—pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution—is coordinated with the relative distance: When the wet film is in the pore-dominant region, reduce the relative distance and adjust the pumping rate or pressure drop rate to enhance the local desolvation uniformity and wet film locking ability. When the wet film is in the predominantly pitted area, the relative distance and the distribution of the extraction area are adjusted to reduce the local pressure gradient and microscale lateral flow. When the wet film is in the area dominated by suction marks, the relative distance is increased and the local suction intensity at the position corresponding to the suction mark is reduced to weaken the local airflow impact and directional shearing. When the wet film is in the stable film-forming region, maintain the current combination of vacuum drying parameters.

3. The method for controlling the pressure field of vacuum drying of perovskite wet film as described in claim 1, characterized in that, The defect phase diagram is pre-established in the following manner: Under the same coating conditions and the same perovskite precursor system, by changing the combination of vacuum drying parameters, the film surface state under different parameter combinations can be obtained. Obtain defect statistics for each membrane surface condition; the defect statistics include at least one of the following: number of transparent holes per unit area, number of pits per unit area, area of ​​wavy region, and spatial correlation between defects and the location of air extraction holes; Based on the aforementioned defect statistics, each combination of vacuum drying parameters is divided into a pore-dominant region, a pit-dominant region, a sampling mark-dominant region, or a stable film-forming region. Using process conditions, including at least two parameters from the vacuum drying parameter combination, as dimensions, a mapping relationship is established between the values ​​of each dimension and the divided film surface states to form the defect phase diagram.

4. The method for controlling the pressure field during vacuum drying of perovskite wet films as described in claim 1, characterized in that, The air extraction area includes multiple partitions, and the air extraction unit includes partition air extraction channels corresponding to the partitions and partition valves that control the air extraction intensity of each partition. The defect information also includes the spatial correlation between the defect and the partition. Accordingly, the step of coordinating the adjustment of at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution relative to the relative distance according to the parameter adjustment strategy includes: When there is a spatial correlation between the sampling mark and one of the partitions, reduce the valve opening of that partition or increase the relative distance; When the holes are concentrated in one of the partitions, the relative distance is reduced, or the air extraction efficiency of that partition is increased.

5. The method for controlling the pressure field of vacuum drying of perovskite wet film as described in claim 4, characterized in that, A pressure equalization and flow guiding structure is provided between the air extraction unit and the wet film. The pressure equalization and flow guiding structure includes at least one of a buffer cavity, a porous pressure equalization plate, a flow guiding layer, and an edge pressure relief groove. Accordingly, the step of coordinating the adjustment of at least one of the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution relative to the relative distance according to the parameter adjustment strategy further includes: When the wet film is in the predominant area of ​​pitting, the porous pressure equalizing plate or the flow guiding layer is activated to convert the point-like air extraction of the air extraction unit into surface air extraction. When the wet film is in the area dominated by suction marks, the buffer chamber is activated to weaken the local low-pressure peak near the suction port, or the pressure difference between the edge area and the center area is reduced by the edge pressure relief groove.

6. The method for controlling the pressure field of vacuum drying of perovskite wet film as described in claim 1, characterized in that, The vacuum contact drying is performed in three stages, including: The first stage is the pre-stabilization and desolvation stage, in which the wet film is evacuated at a first evacuation rate while the relative distance is maintained at a first distance. The second stage is the enhanced desolvation and locking stage, in which the wet film is evacuated at a second evacuation rate greater than the first evacuation rate, or the relative distance is reduced to a second distance less than the first distance. The third stage is the post-stabilization stage, which involves holding the pressure for a preset time after reaching the final pressure.

7. The method for controlling the pressure field during vacuum drying of perovskite wet films as described in claim 1, characterized in that, The acquisition of defect information on the surface of the vacuum-contact-dried perovskite precursor wet film includes: Acquire images of the surface of the wet film; The membrane image is preprocessed; Candidate regions for holes, pits, and scratches are extracted from the preprocessed membrane image; Extract the defect features of the candidate region; the defect features include at least one of the following: defect number, area, equivalent diameter, aspect ratio, roundness, grayscale contrast, texture variance, density per unit area, orientation consistency, arc fitting degree, and spatial correlation between the defect and the evacuation area. Based on the defect characteristics, output the defect category and the defect index vector composed of the defect characteristics.

8. The method for controlling the pressure field of vacuum drying of perovskite wet film as described in claim 7, characterized in that, Based on the defect type in the defect information, the flow instability range of the wet film is determined, including: When the arc fitting degree or directional consistency of the candidate region of the sampling mark exceeds the third threshold, the wet film is determined to be in the sampling mark dominant region. When the arc fitting degree and direction consistency of the candidate region of the burr mark do not exceed the third threshold, and the gray-scale contrast or unit area density of the candidate region of the hole exceeds the first threshold, the wet film is determined to be in the hole-dominant region. When the arc fitting degree and direction consistency of the candidate region of the puncture mark do not exceed the third threshold, and the gray contrast and unit area density of the candidate region of the hole do not exceed the first threshold, and the unit area density or texture variance of the candidate region of the pit exceeds the second threshold, the wet film is determined to be in the pit-dominant region. When the arc fitting degree and direction consistency of the candidate region for the burr mark, the grayscale contrast and unit area density of the candidate region for the hole, and the unit area density and texture variance of the candidate region for the pit do not exceed the corresponding thresholds, the wet film is determined to be in the stable film formation region.

9. A pressure field control device for vacuum drying of perovskite wet film, characterized in that, include: The data acquisition module is used to acquire defect information on the surface of the perovskite precursor wet film after vacuum contact drying. The interval identification module is used to determine the flow instability interval of the wet film based on the defect type in the defect information; the flow instability interval includes the pore-dominated region, the pit-dominated region, the pump mark-dominated region, and the stable film-forming region; The strategy determination module is used to determine the parameter adjustment strategy corresponding to the flow instability range based on the preset defect phase diagram; the defect phase diagram represents the mapping relationship between the flow instability range and the vacuum drying parameter combination, and the vacuum drying parameter combination includes at least the relative distance between the wet film and the pumping unit, and at least one of the following: pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution. The adjustment module is used to coordinately adjust at least one of the following parameters and relative distances according to the parameter adjustment strategy: the pumping rate, pressure drop rate, final pressure, holding time, and pumping area distribution, so that the vacuum contact drying process after adjustment enters the stable film formation zone.

10. A pressure field control system for vacuum drying of perovskite wet films, characterized in that, include: A substrate support assembly for supporting a substrate on which a perovskite wet film has been formed; An air extraction assembly is disposed above the wet film and includes partitioned air extraction channels and partitioned valves that control the air extraction intensity of each partition respectively. A pressure equalization and flow guiding component is disposed between the air extraction component and the wet film, and includes a buffer chamber, a porous pressure equalization plate and a flow guiding layer arranged sequentially from top to bottom; The gap adjustment assembly includes a drive mechanism and a displacement detection mechanism. The drive mechanism is used to drive the air extraction assembly, the pressure equalization and flow guiding assembly, or the substrate support assembly to rise and fall to change the relative distance between the wet film and the air extraction assembly. The displacement detection mechanism is used to provide feedback on the relative distance. Detection components are used to acquire membrane surface images and / or pressure information; A control component is used to control the gap adjustment component, the air extraction component, and the partition valve according to the defect type reflected by the membrane image and based on a defect phase diagram; the defect phase diagram characterizes the mapping relationship between the flow instability range of the membrane surface and the combination of vacuum drying parameters.

Images