Synergistic control method for inhibiting high-resolution inkjet film formation defects of perovskite functional layer and related device

Abstract

This application relates to a collaborative control method and related apparatus for suppressing high-resolution inkjet film formation defects in perovskite functional layers. The method includes configuring a satellite-free droplet waveform containing multi-level pull-back signals based on ink rheological properties; establishing a mapping relationship between physical nozzles and logic voltage channel groups based on nozzle performance deviations, and performing voltage calibration on abnormal nozzles; generating gradient-compensated printing data based on the thickness distribution of the test film layer, and using non-uniform pixel density to offset macroscopic solute migration; and a control system collaboratively loading the above data, mapping relationship, and waveform to perform fabrication. This application successfully applies a 1200 DPI high-resolution industrial printhead to the fabrication of perovskite fully functional layers, eliminating line-drawing and water-ripple defects from a mechanistic perspective, solving the industry problem of inconsistent edge and center shrinkage in large-area printing, and significantly improving battery yield and photoelectric conversion efficiency.

Description

Technical Field

[0001] This application relates to the field of thin-film solar cell manufacturing processes, and in particular to a synergistic control method and related apparatus for suppressing defects in high-resolution inkjet film formation of perovskite functional layers. Background Technology

[0002] The industrial manufacturing of perovskite thin-film solar cells is developing towards a balance between large area and high efficiency. Using high-resolution industrial-grade array nozzles for functional layer fabrication has become a key process for improving module performance. However, in high-precision photovoltaic functional layer printing, film quality is intricately influenced by the coupling of multiple physical processes, including fluid dynamics, hardware manufacturing precision, and drying thermodynamics, creating a difficult-to-separate control challenge.

[0003] This complexity is primarily manifested in the unique rheological properties of perovskite precursors and related functional layer inks. These inks typically possess specific viscosity and surface tension windows, requiring precise matching of driving energy to overcome fluid resistance. However, a single driving waveform often struggles to ensure both powerful jet ejection and cleanliness at the moment of breakup, easily inducing satellite droplets or tailing phenomena at the microscopic level. This microscopic jet instability further compresses the operational space for compensating for printhead hardware errors.

[0004] In industrial applications, the thousands of nozzles integrated within a microelectromechanical system (MEMS) array printhead inevitably exhibit manufacturing tolerances. Due to the limitations imposed by the ink's rheological properties on the waveform adjustment range, a uniform drive signal alone cannot correct for jet velocity and volume variations caused by hardware tolerances. This results in mesoscopic streaks or thickness fluctuations in the wet film during the initial deposition stage. More critically, even if an ideal initial wet film distribution is achieved, during the drying process of converting a large-area liquid film into a solid film, the difference in solvent evaporation rates between the substrate edge and center drives macroscopic migration of the solute across regions. This thermodynamic behavior disrupts the originally uniform solute distribution, causing a final film thickness inconsistency between the edge and center.

[0005] Existing control technologies typically treat the above process in a fragmented manner, such as simply improving droplet morphology through waveform shaping or using image algorithms to repair hardware defects. However, such discrete control strategies are difficult to balance microscopic jet quality and macroscopic drying uniformity within a limited process window. Summary of the Invention

[0006] In order to balance micro-jet quality and macro-drying uniformity within a limited process window, this application provides a synergistic control method and related apparatus for suppressing high-resolution inkjet film formation defects in perovskite functional layers.

[0007] Firstly, this application provides a synergistic control method for suppressing defects in high-resolution inkjet film formation of perovskite functional layers, employing the following technical solution: A synergistic control method for suppressing defects in high-resolution inkjet film formation of perovskite functional layers includes the following steps: S1. Configure a piezoelectric driving waveform according to the rheological properties of the perovskite functional layer ink to be printed; wherein, the piezoelectric driving waveform includes a multi-stage pull-back signal for cutting off the jet tail when the ink droplet leaves the nozzle; S2. Obtain the jetting performance parameters of each nozzle in the inkjet printhead; based on the different deviations of the jetting performance parameters from the preset standard threshold, establish a mapping relationship between the nozzle and different preset voltage channel groups, wherein different voltage channel groups correspond to different driving voltage compensation values, and the driving voltage compensation values ​​are used to calibrate the reference voltage amplitude of the piezoelectric driving waveform. S3. Obtain the thickness distribution data of the cured film layer based on the full-frame test print on the substrate to analyze the macroscopic solute migration trend; generate gradient compensation printing data according to the macroscopic solute migration trend; wherein, the gradient compensation printing data has a non-uniform pixel density distribution in different areas of the substrate; S4. The control system loads the gradient-compensated printing data and, according to the mapping relationship, applies a piezoelectric driving waveform calibrated based on the driving voltage compensation value to different voltage channel groups to drive the inkjet printhead to complete the perovskite functional layer preparation on the substrate.

[0008] Optionally, S1 includes the following sub-steps: S11. Set a rising edge signal with a preset slope, wherein the rising edge signal is used to provide kinetic energy to overcome the viscous resistance of the ink in the perovskite functional layer; S12. After the rising edge signal, a two-step or multi-step stepped falling edge signal is set; wherein, the two-step or multi-step stepped falling edge signal releases the piezoelectric cavity pressure in stages, actively absorbs the surface energy of the jet tail, and causes the liquid column to undergo clean fracture and retraction at the nozzle plane.

[0009] Optionally, the piezoelectric driving waveform is configured as a dual-pulse combined driving waveform, which is composed of a main injection pulse with a large amplitude and a disturbance suppression pulse with a smaller amplitude after a preset time interval in terms of timing. The main jet pulse is used to drive the piezoelectric cavity of the nozzle to perform suction and extrusion actions, so as to give the ink droplets the active energy to detach from the nozzle. The disturbance suppression pulse is applied during the residual oscillation stage after the ink droplet leaves the nozzle, and the voltage amplitude of the disturbance suppression pulse is configured to be less than the voltage amplitude of the main jet pulse; wherein, the disturbance suppression pulse drives the piezoelectric cavity to deform, and applies a reverse damping force to the fluid meniscus at the nozzle to counteract the liquid surface oscillation caused by mechanical rebound and suppress satellite droplet formation.

[0010] Optionally, the sub-step of S2 includes: S21. Iterate through and test the droplet flight speed and single-point ink volume of each of the nozzles; S22. Identify several abnormal nozzles whose discrete distributions exceed the preset standard threshold range, where the ink droplet flight speed or the amount of ink at a single point exceeds the preset standard threshold range. S23. Construct a mapping matrix in the drive control software to logically merge the several abnormal nozzles that are not continuous in spatial location into different correction voltage channel groups based on the degree of deviation from the preset standard threshold range, and merge the nozzles that do not exceed the preset standard threshold range into the standard voltage channel group; wherein, the voltage channel group is divided into the standard voltage channel group and several correction voltage channel groups. S24. Configure the corrected voltage channel group with a non-zero drive voltage compensation value so that the voltage amplitude applied to the abnormal nozzle is different from that of the standard voltage channel group.

[0011] Optionally, the sub-step of S3 includes: S31. Perform a full-frame test print on the substrate using uniform dot matrix data, and measure the full-field thickness of the cured film layer after curing. S32. Identify thickness anomaly regions caused by differences in solvent evaporation rates, wherein the macroscopic thickness anomaly regions include accumulation regions with thicknesses higher than a preset average thickness and depression regions with thicknesses lower than the preset average thickness; the positions of the accumulation regions and the depression regions on the substrate vary depending on the ink droplet solvent; S33. Perform sparsification processing on the printing data corresponding to the stacking area to reduce the printing dot density of the stacking area; S34. Encrypt and fill the printed data corresponding to the recessed area to increase the density of the printed dot matrix in the recessed area; S35. Generate the final gradient-compensated print data based on the processed print data.

[0012] Optionally, the sub-step of S3 includes: superimposing micro-blocking texture data on the gradient-compensated printing data; the micro-blocking texture data is used to form a micro-groove structure on the wet film surface that hinders the continuous flow of solute, so as to physically block the macroscopic migration of solute.

[0013] Optionally, the gradient compensation printing data is configured such that the gradient compensation printing data of the substrate adopts a pixel density gradient arrangement with sparse outer edges and dense inner edges, wherein the pixel density of the outermost edge region is 5% to 15% lower than that of the central region, in order to balance the outward convection deposition of solute caused by solvent evaporation.

[0014] Secondly, the inkjet printing control system provided in this application adopts the following technical solution: An inkjet printing control system includes: A waveform controller is configured to store and output the piezoelectric drive waveform; A multi-channel driving circuit has multiple independently controllable voltage output channels, wherein the multiple independently controllable voltage output channels are respectively connected to different nozzle regions of the high-resolution inkjet printhead and are configured to support logical remapping of any of the physical nozzles. The data processing module is configured to receive the gradient-compensated printing data and allocate the printing data to the corresponding physical nozzles according to the mapping relationship. The central processing unit is configured to perform the calculation of the dynamic logic grouping step of establishing nozzles in S2, calibrate the driving voltage compensation value against the reference voltage amplitude and write it into the register of the multi-channel driving circuit, and coordinate the synchronous operation of the waveform controller and the data processing module to output the final piezoelectric driving waveform.

[0015] Thirdly, the computer device provided in this application adopts the following technical solution: A computer device comprising: One or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, the one or more applications being configured to: The above-described synergistic control method for suppressing defects in high-resolution inkjet film formation of perovskite functional layers is implemented.

[0016] Fourthly, the computer-readable storage medium provided in this application adopts the following technical solution: A computer-readable storage medium storing a computer program that can be loaded by a processor and executed as described above.

[0017] The storage medium stores at least one instruction, at least one program, a code set, or an instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement the following: The above describes a synergistic control method for suppressing defects in high-resolution inkjet film formation of perovskite functional layers.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. This application establishes a mapping relationship between physical nozzles and logic voltage channels, and presets dedicated drive waveforms. This allows for system-level calibration of the inherent hardware discreteness and fundamental fluid characteristics before the device is delivered to the user for specific printing tasks. This pre-adaptation mechanism ensures that the printing device is always in optimal readiness when facing diverse printing jobs, effectively shielding the interference of underlying hardware differences on process results, reducing sensitivity to subsequent process debugging accuracy, and thus providing users with a wider operating space and fault tolerance range. 2. This application overcomes the control challenges faced by high-resolution MEMS printheads when processing perovskite functional layer inks with complex rheological properties (such as high viscosity or fast evaporation) by establishing a three-level collaborative mechanism of waveform control, hardware grouping, and data compensation. It avoids the scenarios that traditional single control methods may encounter when adjusting parameters, such as the contradiction caused by sacrificing jet stability in pursuit of uniform drying. 3. This application utilizes a dedicated drive waveform containing multi-stage pull-back signals to actively cut off the jet tail at the microscopic level, eliminating the generation of satellite droplets; simultaneously, combined with dynamic logic grouping calibration of physical nozzles, it eliminates jetting differences caused by hardware tolerances. It also effectively mitigates the effects of fluid disturbance and drying shrinkage tendencies during high-frequency jetting, ensuring the smoothness of the film surface. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a synergistic control method for suppressing high-resolution inkjet film defects in perovskite functional layers is shown in one embodiment of the present invention.

[0020] Figure 2 A schematic diagram illustrating a piezoelectric drive waveform in one embodiment of the present invention is shown. Detailed Implementation

[0021] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0022] Perovskite solar cells consist of a transparent conductive electrode, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a stack of metal electrodes. The fabrication of the functional layer thin film determines the device performance. Compared to traditional coating processes such as spin coating or blade coating, inkjet printing technology features high material utilization, support for digital patterning, and non-contact deposition.

[0023] Applying high-resolution inkjet printing to the preparation of perovskite functional layers presents the following challenges: First, perovskite functional layer inks have rheological properties such as high viscosity, high surface tension, or high volatility; second, high-resolution inkjet printheads integrate a large number of nozzles, and manufacturing tolerances exist between the nozzles, making it difficult to guarantee droplet consistency; third, during the drying process of large-area wet films, differences in solvent evaporation rates can lead to solute migration, causing defects such as line drawing and uneven thickness.

[0024] like Figure 1 As shown, this embodiment provides a collaborative control method for suppressing high-resolution inkjet film defects in perovskite functional layers. The method mainly includes steps S1 to S4. First, step S1 is performed: a piezoelectric driving waveform is configured according to the rheological characteristics of the ink in the perovskite functional layer to be printed; wherein, the piezoelectric driving waveform includes a multi-stage pull-back signal for cutting off the jet tail when the ink droplet leaves the nozzle.

[0025] In this embodiment, the perovskite functional layer ink to be printed is a perovskite precursor solution or a transport layer solution. The inkjet printer uses a piezoelectric ceramic element inside the printhead to respond to a voltage signal, generating mechanical deformation that squeezes the ink chamber and ejects the ink from the nozzle. Perovskite precursor inks typically contain solvents such as DMF or DMSO, exhibiting high viscosity and high surface tension; while some transport layer inks are highly volatile. These rheological properties cause the ink to easily form a slender liquid column behind the main droplet, i.e., the jet tail, when ejected under pressure.

[0026] If the fracture behavior of the jet tail cannot be effectively controlled, the tail will break off and form tiny droplets independent of the main droplet, i.e., satellite droplets, or irregular string defects on the substrate. The piezoelectric drive waveform controls the action of the piezoelectric ceramic through a combination of voltage amplitude and timing. The multi-stage pull-back signal is manifested in the time domain as a step-like decrease in the driving voltage. This signal utilizes the graded reset action of the piezoelectric ceramic to generate a controllable negative pressure inside the ink cavity. This negative pressure acts on the ejected fluid, actively cutting off the jet tail from a hydrodynamic perspective, rather than relying on the surface tension of the fluid itself to naturally break it off, thereby avoiding the formation of satellite droplets and ensuring the edge clarity of single-point jetting.

[0027] Specifically, step S1 can be further refined into sub-steps S11 to S12.

[0028] S11. Set a rising edge signal with a preset slope, wherein the rising edge signal is used to provide kinetic energy to overcome the viscous resistance of the ink in the perovskite functional layer.

[0029] When a rising edge signal is applied to the piezoelectric actuator, the piezoelectric crystal undergoes mechanical deformation, causing the ink cavity volume to be compressed. This increases the fluid pressure within the cavity and propels the ink towards the nozzle. The slope of the rising edge determines the kinetic energy transfer efficiency. For high-viscosity perovskite inks, the rising edge slope must match the ink's viscous resistance: a slope that is too low will result in insufficient kinetic energy to overcome the viscous forces, preventing effective jetting; a slope that is too high may cause cavitation within the fluid or excessive splashing.

[0030] S12. After the rising edge signal, a two-step or multi-step stepped falling edge signal is set; wherein, the two-step or multi-step stepped falling edge signal releases the piezoelectric cavity pressure in stages, actively absorbs the surface energy of the jet tail, and causes the liquid column to undergo clean fracture and retraction at the nozzle plane.

[0031] Unlike the traditional single-step falling edge that instantly restores the cavity to its original shape, the stepped falling edge allows for precise control of the cavity recovery process. By reducing the voltage in stages, the cavity volume gradually recovers, thereby generating a graded negative pressure. This graded negative pressure successively absorbs the surface energy of the jet tail, limiting excessive elongation of the liquid column. Clean fracture refers to the complete separation of the liquid column at the nozzle plane without any tailing or filament residue. This fracture method avoids ink accumulation on the nozzle surface and eliminates stringing defects caused by fluid dragging.

[0032] In a preferred embodiment, refer to Figure 2 The piezoelectric driving waveform is configured as a dual-pulse combined driving waveform, which is composed of a main injection pulse with a large amplitude and a disturbance suppression pulse with a smaller amplitude after a preset time interval in terms of timing. The main jet pulse is used to drive the piezoelectric cavity of the nozzle to perform suction and extrusion actions, so as to give the ink droplets the active energy to detach from the nozzle. The disturbance suppression pulse is applied during the residual oscillation stage after the ink droplet leaves the nozzle, and the voltage amplitude of the disturbance suppression pulse is configured to be less than the voltage amplitude of the main jet pulse; wherein, the disturbance suppression pulse drives the piezoelectric cavity to deform, and applies a reverse damping force to the fluid meniscus at the nozzle to counteract the liquid surface oscillation caused by mechanical rebound and suppress satellite droplet formation.

[0033] Specifically, the dual-pulse combined drive waveform is represented in the time domain as two trapezoidal or square wave pulses with negative or positive polarity, separated by a zero-level holding time. It should be noted that the polarity can be negative or positive in different printhead types; this example uses negative polarity. The first pulse is the main jet pulse, and the second pulse is a disturbance suppression pulse. The main jet pulse's working cycle follows a suction-then-jet dynamic mechanism: when the falling edge of the main jet pulse arrives, the drive voltage rapidly drops from zero to a negative high voltage, causing the piezoelectric actuator to deform the cavity wall outward, expanding the ink cavity volume and drawing ink from the ink supply channel into the cavity; after a preset holding time, the rising edge of the main jet pulse arrives, the voltage rapidly returns to zero, the piezoelectric actuator abruptly resets and compresses the cavity, generating a high-intensity acoustic pressure wave that forces ink droplets out of the nozzle.

[0034] After ink droplet ejection, a disturbance suppression pulse is applied to mitigate the accompanying residual oscillations. The voltage amplitude of this pulse is strictly set to be lower than that of the main ejection pulse. The physical significance of this amplitude difference lies in energy matching: the main ejection pulse requires sufficient energy to overcome fluid viscous resistance and surface tension to achieve ejection, while the disturbance suppression pulse only needs to generate a moderate amount of micro-disturbance to counteract the oscillations. If the disturbance suppression pulse amplitude is too large, it may cause internal pressure fluctuations to exceed the ejection threshold, triggering unexpected secondary ejection. Mechanically, the intervention of the disturbance suppression pulse corresponds to the mechanical rebound phase of the piezoelectric cavity and fluid interface, at which point the fluid meniscus at the nozzle is in an unstable oscillating state. The disturbance suppression pulse drives a slight volume change in the piezoelectric cavity, generating an active damping force within the fluid that is opposite in direction to the residual oscillations. This damping force forcibly stabilizes the unstable meniscus at the moment of oscillation, allowing it to quickly return to a state of static equilibrium.

[0035] Then execute S2: obtain the jetting performance parameters of each nozzle in the inkjet printhead; based on the different deviations of the jetting performance parameters from the preset standard threshold, establish the mapping relationship between the nozzle and different preset voltage channel groups, wherein different voltage channel groups correspond to different driving voltage compensation values, and the driving voltage compensation values ​​are used to calibrate the reference voltage amplitude of the piezoelectric driving waveform.

[0036] Specifically, the jetting performance parameters mentioned in step S2 mainly include droplet flight speed and single-droplet volume. These two physical indicators determine the printing accuracy and film thickness. Differences in droplet flight speed lead to different arrival times of droplets on the substrate. During the printing process, with the printhead and substrate moving relative to each other, this time difference translates into spatial droplet deviation, i.e., flight deviation. If there are differences in single-droplet volume, it will result in uneven ink deposition per unit area. These differences manifest microscopically as pixel misalignment or inconsistent sizes, and macroscopically as visible streaks, color differences, or thickness fluctuations in the film, severely affecting the photoelectric uniformity of the perovskite functional layer.

[0037] Even with high-precision MEMS manufacturing processes, industrial-grade inkjet printheads (such as array printheads containing thousands of nozzles) inevitably exhibit manufacturing tolerances during production. For example, the uniformity of the piezoelectric actuator film thickness, micron-level errors in nozzle diameter, and minute differences in flow channel etching can all lead to inherent performance variations in different nozzles under the same driving voltage. This physical inconsistency is an inherent property of the hardware itself and cannot be eliminated simply by using a uniform external waveform.

[0038] At the hardware architecture level, for industrial nozzles integrating tens of thousands of high-density nozzles, configuring an independent waveform generator and high-voltage amplifier circuit for each nozzle is impractical in engineering, as this would greatly increase the size, power consumption, and cost of the drive circuit. Therefore, the drive circuit design used in the embodiments of this application adopts a group control architecture, that is, providing a limited number (e.g., 4 or 8 groups) of shared voltage channels.

[0039] Under this architectural constraint, a mapping relationship is established to break the limitation of the physical location of the nozzles and realize logical reorganization based on performance characteristics. The system no longer groups nozzles according to their physical arrangement order (such as nozzles 1 to 100). Instead, it uses software algorithms to logically merge nozzles that are physically scattered but have similar performance deviations (such as all nozzles with a flow rate 5% higher, regardless of whether they are located at the ends or in the middle of the nozzle head) into the same control group.

[0040] Based on the above mapping, the system calibrates the reference voltage amplitude by adjusting the driving voltage compensation value. According to the inverse piezoelectric effect, the mechanical deformation of the piezoelectric ceramic is determined by the applied voltage amplitude, and the deformation is directly positively correlated with the pressure change in the ink cavity and the final ejection energy. For nozzle groups classified as having excessive ejection (such as excessive flow rate or excessive volume), the system assigns a reduced voltage amplitude (negative compensation) to reduce their piezoelectric deformation; conversely, for nozzle groups with insufficient ejection, an increased voltage amplitude (positive compensation) is assigned. Through this targeted voltage fine-tuning, the flight speed and ink volume exhibited by all groups at the physical output end tend to be consistent, thereby smoothing out the impact of manufacturing tolerances at the hardware level.

[0041] Furthermore, the specific execution process of step S2 includes sub-steps S21 to S24.

[0042] S21. Iterate through and test the droplet flight speed and single-point ink volume of each of the nozzles.

[0043] In an optional embodiment, the testing process is performed by printing a nozzle calibration pattern. The control system drives the inkjet printhead to print a test pattern containing positioning lines and grayscale blocks on the substrate. By visually observing or optically scanning and analyzing the test pattern, the droplet flight speed is calculated based on the droplet position deviation, and the amount of ink per droplet is estimated based on the line width or optical density.

[0044] In another alternative embodiment, the testing process can also be performed using an integrated droplet observation instrument or an external high-speed stroboscopic imaging system. The system controls the printhead to eject ink droplets one by one or in groups, using a stroboscopic light source synchronized with the ejection frequency for illumination, and a high-speed camera to capture images of the ink droplets flying at specific moments. Image processing algorithms are used to analyze the displacement of the ink droplets within a preset time interval to calculate the flight speed, and the amount of ink per droplet is estimated based on the projected area of ​​the droplets in the image.

[0045] S22. Identify several abnormal nozzles whose discrete distributions exceed the preset standard threshold range, where the ink droplet flight speed or the amount of ink at a single point exceeds the preset standard threshold range.

[0046] Due to the randomness of the manufacturing process, these abnormal nozzles are not concentrated in a specific area of ​​the nozzle head, but rather exhibit a random and discontinuous discrete distribution in physical space. For example, nozzle number 10 may have an excessively high flow rate, while the adjacent nozzle number 11 is normal, and nozzle number 200 exhibits an excessively slow flow rate. This discrete distribution characteristic renders traditional overall adjustment methods based on physical regions ineffective, necessitating independent identification and management of individual nozzles.

[0047] This embodiment provides two specific implementation paths for identifying abnormal nozzles. The first path is visual analysis based on human experience. Operators directly observe the printed verification pattern and judge the integrity of lines and the uniformity of color blocks based on experience. For areas with broken lines, faint lines, or obvious misalignments, the corresponding nozzle is identified as an abnormal nozzle and manually marked in the control software. The second path is automatic image recognition based on machine vision. The system calls image processing algorithms to perform binarization and connected component analysis on the acquired pattern data, automatically calculating the pixel continuity and grayscale integral value of each positioning line. When the calculation result is lower than a preset qualified threshold, the algorithm automatically marks the nozzle as abnormal.

[0048] It's important to note that the aforementioned differences in jet performance primarily stem from the clogging status of the nozzles. Industrial-grade inkjet printheads typically exhibit high consistency upon initial manufacturing, but over time, ink drying or impurity deposition can lead to varying degrees of physical clogging in some nozzles. This clogging isn't a simple complete blockage; rather, it manifests as a partial blockage, resulting in reduced droplet ejection speed or decreased ink output per burst. Given that industrial-grade inkjet printheads are high-value, precision components, directly replacing them entirely due to a few blocked nozzles is not economically efficient. Therefore, this step distinguishes between clogged, partially blocked, and normal nozzles—that is, abnormal and non-abnormal nozzles—for appropriate application.

[0049] S23. Construct a mapping matrix in the drive control software to logically merge the several abnormal nozzles that are not continuous in spatial location into different correction voltage channel groups based on the degree of deviation from the preset standard threshold range, and merge the nozzles that do not exceed the preset standard threshold range into the standard voltage channel group; wherein, the voltage channel group is divided into the standard voltage channel group and several correction voltage channel groups.

[0050] At the software level, the mapping matrix is ​​represented as a lookup table or index array, where the key is the physical address ID of the nozzle and the value is the group ID of the logical voltage channel. The logical merge operation essentially ignores the physical distance between nozzles and clusters them only based on their performance characteristics. For example, the system maps nozzle number 10 on the left side of the nozzle and nozzle number 2000 on the right side of the nozzle to the same corrected voltage channel group because they both exhibit a higher flow rate.

[0051] S24. Configure the corrected voltage channel group with a non-zero drive voltage compensation value so that the voltage amplitude applied to the abnormal nozzle is different from that of the standard voltage channel group.

[0052] This step employs a reverse compensation strategy. Specifically, for abnormal nozzle groups identified as having excessively high droplet velocity or excessive ink volume, the system applies a negative drive voltage compensation value, reducing the final voltage amplitude applied to these nozzles and thus decreasing the amplitude of the piezoelectric ceramic to suppress jetting energy. Conversely, for abnormal nozzle groups with excessively low droplet velocity or insufficient ink volume, the system applies a positive drive voltage compensation value, increasing the drive voltage amplitude to supplement jetting kinetic energy. This differentiated voltage configuration ensures consistency across all nozzles at the physical output.

[0053] Simultaneously or subsequently, step S3 is executed: based on the full-frame test print on the substrate, the thickness distribution data of the cured film layer is obtained to analyze the macroscopic solute migration trend; gradient compensation printing data is generated according to the macroscopic solute migration trend; wherein, the gradient compensation printing data has a non-uniform pixel density distribution in different areas of the substrate.

[0054] In inkjet printing of large-area perovskite functional layers, the wet film faces a complex physical transport process during the drying and curing stage. Due to capillary flow caused by solvent evaporation (i.e., the coffee ring effect) and Marengoni convection induced by surface tension gradients, solutes in the ink often undergo significant macroscopic migration. This migration phenomenon leads to uneven distribution of the dried solid film layer, with edge thickening or central depression, even if the initial deposited wet film thickness is uniform. Although the waveform control in step S1 and the hardware calibration in step S2 ensure the volumetric and positional accuracy of the ink droplet landing point, these two steps mainly affect the fluid jet dynamics level and cannot intervene in the thermodynamic phase transition and solute transport behavior that lasts for several minutes during the subsequent drying process.

[0055] The purpose of full-frame test printing is to capture the final film-forming state under the coupling effect between ink, substrate, and environmental field. By acquiring the thickness distribution data of the cured film, the system can directly quantify and characterize the macroscopic migration trend of solute. The thickness distribution data is essentially a mapping of the solute migration path: areas with significantly higher thickness than the theoretical value indicate that they are the convergence points of solute migration, while areas with lower thickness indicate that they are the source of solute outflow. Based on this analysis, the system pre-constructs an initial ink volume distribution that is opposite to the natural drying shrinkage trend. That is, excess ink pixels are pre-placed in areas where solute loss is expected, and ink pixels are reduced in areas where solute accumulation is expected. The non-uniform distribution of the initial ink volume is used to offset the non-uniform shrinkage during the drying process, thereby obtaining a smooth and uniform film after final curing.

[0056] As a specific implementation of step S3, the process includes sub-steps S31 to S35.

[0057] S31. Perform a full-frame test print on the substrate using uniform dot matrix data, and measure the full-field thickness of the cured film layer after curing.

[0058] Optionally, S31 can specifically involve using a machine vision inspection system equipped with a coaxial light source to perform full-frame test printing observation on a substrate using uniform dot matrix data. The light emitted by the coaxial light source is refracted by a semi-transparent and semi-reflective beam splitter and then vertically illuminates the wet film surface. The reflected light returns along the original path of the camera's optical axis.

[0059] S32. Identify thickness anomaly regions caused by differences in solvent evaporation rates, wherein the macroscopic thickness anomaly regions include accumulation regions with thicknesses higher than a preset average thickness and depression regions with thicknesses lower than the preset average thickness; the positions of the accumulation regions and the depression regions on the substrate vary depending on the ink droplet solvent.

[0060] S33. Perform sparsification processing on the printing data corresponding to the stacking area to reduce the printing dot density of the stacking area.

[0061] S34. The printing data corresponding to the recessed area is encrypted and filled to increase the printing dot density of the recessed area.

[0062] S35. Generate the final gradient-compensated print data based on the processed print data.

[0063] In the region identification step S32, the formation of accumulation and depression regions often stems from differences in the gas-liquid interface at different locations on the substrate. For example, in conventional solvent systems, the solvent evaporation rate at the substrate edge is usually faster than in the central region, driving the liquid flow to carry solute to the outer edge, resulting in accumulation regions at the edge and depression regions at the center. However, for some solvents with specific surface tension characteristics, Marengoni convection may dominate and reverse this process; therefore, the specific distribution of abnormal regions needs to be dynamically determined based on actual measurement results.

[0064] For the identified accumulation areas, step S33 employs a sparsity processing algorithm, such as an error diffusion dithering algorithm or a random selection method. This process, while maintaining the macroscopic continuity of the pattern, randomly removes some pixels, thereby reducing the total amount of deposited ink within that micro-area without changing the volume of individual ink droplets. Conversely, optionally, for recessed areas, step S34 can also perform a densification filling process, inserting additional pixels into the gaps of the original uniform dot matrix. This process must adhere to the boundary constraint principle, i.e., the increased pixel density must not exceed the density of the nozzles. The above steps together constitute a closed-loop iterative logic of trial printing-measurement-feedback-compensation, correcting the digital model through physical experimental data to ensure that the final gradient-compensated printing data can accurately neutralize film formation deviations in the actual production environment.

[0065] Optionally, the sub-step of S3 includes: superimposing micro-blocking texture data on the gradient-compensated printing data; the micro-blocking texture data is used to form a micro-groove structure on the wet film surface that hinders the continuous flow of solute, so as to physically block the macroscopic migration of solute.

[0066] Specifically, microscopic blocking texture data does not refer to altering the final macroscopic morphology of the film, but rather to a virtual texture artificially introduced into the digital printing data. This texture data is not intended to form visible patterns, but rather to construct microscopic structural differences invisible to the naked eye in the initial stage of wet film drying by fine-tuning the amount of ink ejected or the spacing between adjacent pixels. From a fluid dynamics perspective, when ink is deposited on the substrate, these data-defined minute differences translate into a series of microgrooves or microridges on the wet film surface. These microstructures significantly increase the frictional resistance of the liquid film flowing along the substrate plane, disrupting the continuous fluid channels required for long-distance solute migration. Through this physical blocking mechanism, the solute is confined to deposition within microscopic regions and cannot flow with the solvent evaporation to high-concentration areas, thus effectively suppressing solute aggregation at the macroscopic scale.

[0067] At the data processing level, the overlay strategy is implemented through image processing algorithms. The system first generates a low-frequency gradient grayscale image (representing the trend of sparse outer and dense inner areas) based on macroscopic compensation requirements, and then generates a high-frequency microscopic texture image. The control software logically synthesizes the two data layers (e.g., using weighted overlay or masking operations) to generate a final printable slice file containing both macroscopic gradient and microscopic texture information. The print head performs jetting based on this single file, thus simultaneously achieving macroscopic thickness homogenization and microscopic migration blocking in a single scan. It should be noted that in different embodiments, either the density control strategy or the microscopic texture blocking strategy can be executed, or both can be executed simultaneously.

[0068] Optionally, the gradient compensation printing data is configured such that the gradient compensation printing data of the substrate adopts a pixel density gradient arrangement with sparse outer edges and dense inner edges, wherein the pixel density of the outermost edge region is 5% to 15% lower than that of the central region, in order to balance the outward convection deposition of solute caused by solvent evaporation.

[0069] S4. The control system loads the gradient-compensated printing data and, according to the mapping relationship, applies a piezoelectric driving waveform calibrated based on the driving voltage compensation value to different voltage channel groups to drive the inkjet printhead to complete the perovskite functional layer preparation on the substrate.

[0070] The control system utilizes a field-programmable gate array (FPGA) or a high-speed processor to schedule data stream transmission and hardware action execution. The system maintains clock synchronization between bitmap parsing and encoder motion position feedback. The drive circuit dynamically routes physical nozzles to logic channels based on the mapping relationship established in step S2. The system queries the mapping matrix stored in the register, indexes the logic voltage channel group number to which the currently activated physical nozzle number belongs, and determines the power rail or signal path to which the nozzle is connected.

[0071] The signal synthesis module superimposes the drive voltage compensation value set in step S2 onto the drive waveform configured in step S1. A multi-channel high-voltage amplifier performs differentiated gain adjustment or bias superposition on the reference signal. The voltage signal applied to the piezoelectric ceramic possesses both the time-domain characteristics for suppressing satellite droplets and the amplitude characteristics for calibrating the jet energy.

[0072] During the scanning motion of the printhead relative to the substrate, the control system retrieves the gradient-compensated printing data generated in step S3 based on the real-time position coordinates. When the printhead moves to the edge region of the substrate, it reads the sparsed dot matrix data and instructs the printhead to spray at a lower frequency. When the printhead moves to the center region, it reads the dense filling data and instructs the printhead to spray at a higher frequency.

[0073] Step S4 achieves three-level coordination of waveform control, hardware calibration, and data compensation. A single printing action simultaneously optimizes the microscopic morphology of ink droplets, homogenizes the mesoscopic performance of the nozzles, and rationalizes the macroscopic distribution of the wet film. No satellite droplets interfere with the ink droplets upon detachment from the nozzles; their velocity and volume are precisely consistent throughout their flight; and the wet film formed after landing can counteract solute migration during the drying process through a pre-set concentration gradient. This multi-dimensional coordinated control ultimately produces a perovskite functional layer on the substrate that is uniform in thickness, densely crystalline, and free of surface defects, meeting the stringent production requirements of high-performance photovoltaic modules.

[0074] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0075] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the collaborative control method for suppressing high-resolution inkjet film defects in perovskite functional layers as described in the above embodiment.

[0076] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the synergistic control method for suppressing high-resolution inkjet film defects in perovskite functional layers as described in the above embodiments.

[0077] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments of this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0078] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0079] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A synergistic control method for suppressing defects in high-resolution inkjet film formation of perovskite functional layers, characterized in that, Includes the following steps: S1. Configure a piezoelectric driving waveform according to the rheological properties of the perovskite functional layer ink to be printed; wherein, the piezoelectric driving waveform includes a multi-stage pull-back signal for cutting off the jet tail when the ink droplet leaves the nozzle; S2. Obtain the jetting performance parameters of each nozzle in the inkjet printhead; based on the different deviations of the jetting performance parameters from the preset standard threshold, establish a mapping relationship between the nozzle and different preset voltage channel groups, wherein different voltage channel groups correspond to different driving voltage compensation values, and the driving voltage compensation values ​​are used to calibrate the reference voltage amplitude of the piezoelectric driving waveform; S3. Obtain the thickness distribution data of the cured film layer based on the full-frame test print on the substrate to analyze the macroscopic solute migration trend; generate gradient compensation printing data according to the macroscopic solute migration trend; wherein, the gradient compensation printing data has a non-uniform pixel density distribution in different areas of the substrate; S4. The control system loads the gradient-compensated printing data and, according to the mapping relationship, applies a piezoelectric driving waveform calibrated based on the driving voltage compensation value to different voltage channel groups respectively, driving the inkjet printhead to complete the perovskite functional layer preparation on the substrate; The sub-step of S3 includes: S31. Perform a full-frame test print on the substrate using uniform dot matrix data, and measure the full-field thickness of the cured film layer after curing. S32. Identify thickness anomaly regions caused by differences in solvent evaporation rates, wherein the thickness anomaly regions include accumulation regions with thicknesses higher than a preset average thickness and depression regions with thicknesses lower than the preset average thickness; the positions of the accumulation regions and the depression regions on the substrate vary depending on the ink droplet solvent; S33. Perform sparsification processing on the printing data corresponding to the stacking area to reduce the printing dot density of the stacking area; S34. Encrypt and fill the printed data corresponding to the recessed area to increase the density of the printed dot matrix in the recessed area; S35. Generate the final gradient-compensated print data based on the processed print data.

2. The collaborative control method according to claim 1, characterized in that, S1 includes the following sub-steps: S11. Set a rising edge signal with a preset slope, wherein the rising edge signal is used to provide kinetic energy to overcome the viscous resistance of the ink in the perovskite functional layer; S12. After the rising edge signal, a two-step or multi-step stepped falling edge signal is set; wherein, the two-step or multi-step stepped falling edge signal releases the piezoelectric cavity pressure in stages, actively absorbs the surface energy of the jet tail, and causes the liquid column to undergo clean fracture and retraction at the nozzle plane.

3. The cooperative control method according to claim 2, characterized in that, The piezoelectric driving waveform is configured as a dual-pulse combined driving waveform, which consists of a main injection pulse with a large amplitude and a disturbance suppression pulse with a smaller amplitude after a preset time interval in terms of timing. The main jet pulse is used to drive the piezoelectric cavity of the nozzle to perform suction and extrusion actions, so as to give the ink droplets the active energy to detach from the nozzle. The disturbance suppression pulse is applied during the residual oscillation stage after the ink droplet leaves the nozzle, and the voltage amplitude of the disturbance suppression pulse is configured to be less than the voltage amplitude of the main jet pulse; wherein, the disturbance suppression pulse drives the piezoelectric cavity to deform, and applies a reverse damping force to the fluid meniscus at the nozzle to counteract the liquid surface oscillation caused by mechanical rebound and suppress satellite droplet formation.

4. The collaborative control method according to claim 1, characterized in that, The sub-step of S2 includes: S21. Iterate through and test the droplet flight speed and single-point ink volume of each of the nozzles; S22. Identify several abnormal nozzles whose discrete distributions of ink droplet flight speed or single-point ink volume exceed a preset standard threshold. S23. Construct a mapping matrix in the drive control software to logically merge the several abnormal nozzles that are not continuous in spatial location into different correction voltage channel groups based on the degree of deviation from the preset standard threshold, and merge the nozzles that do not exceed the preset standard threshold into the standard voltage channel group; wherein, the voltage channel group is divided into the standard voltage channel group and several correction voltage channel groups. S24. Configure the corrected voltage channel group with a non-zero drive voltage compensation value so that the voltage amplitude applied to the abnormal nozzle is different from that of the standard voltage channel group.

5. The collaborative control method according to claim 1 or 4, characterized in that, The sub-step of S3 includes: superimposing micro-blocking texture data into the gradient-compensated printing data; the micro-blocking texture data is used to form a micro-groove structure on the wet film surface that hinders the continuous flow of solute, so as to physically block macroscopic solute migration.

6. The cooperative control method according to claim 5, characterized in that, The gradient compensation printing data is configured such that the gradient compensation printing data of the substrate adopts a pixel density gradient arrangement with sparse outer edges and dense inner edges, wherein the pixel density of the outermost edge region is 5% to 15% lower than that of the central region, in order to balance the outward convection deposition of solute caused by solvent evaporation.

7. An inkjet printing control system for implementing the cooperative control method as described in any one of claims 1 to 6, characterized in that, include: A waveform controller is configured to store and output piezoelectric drive waveforms; The multi-channel drive circuit has multiple independently controllable voltage output channels, wherein the multiple independently controllable voltage output channels are respectively connected to different nozzle areas of the inkjet printhead and are configured to support logical remapping of any nozzle. The data processing module is configured to receive the gradient-compensated printing data and allocate the printing data to the corresponding nozzles according to the mapping relationship. The central processing unit is configured to perform the calculation of the dynamic logic grouping step of establishing nozzles in S2, calibrate the driving voltage compensation value against the reference voltage amplitude and write it into the register of the multi-channel driving circuit, and coordinate the synchronous operation of the waveform controller and the data processing module to output the final piezoelectric driving waveform.

8. A computer device, characterized in that, It includes: One or more processors; Memory; One or more applications, wherein the one or more applications are stored in the memory and configured to be executed by the one or more processors, the one or more applications being configured to: perform the collaborative control method for suppressing high-resolution inkjet film defects in perovskite functional layers according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The storage medium stores at least one instruction, at least one program, code set, or instruction set, wherein the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by a processor to implement: the collaborative control method for suppressing high-resolution inkjet film defects in perovskite functional layers as described in any one of claims 1 to 6.

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