An adjustable slot coating die for perovskite solar cell production

Abstract

This application discloses an adjustable slit coating die for perovskite solar cell production, relating to the field of perovskite solar cell production equipment technology. It includes a modular slit adjustment structure located at the working end of a coating machine, consisting of an upper die lip and a lower die lip connected by a piezoelectric ceramic drive unit that responds to film thickness monitoring signals. A built-in temperature control module includes a miniature thermoelectric cooler, a temperature sensor, and a DLC coating embedded inside the die, covering the inner wall of the flow channel. An online film thickness monitoring device uses laser interferometry data to measure thickness and provide feedback signals. A chambered flow channel structure includes at least two independent liquid supply chambers, each equipped with a high-precision screw pump and a pressure feedback system. The modular slit adjustment structure achieves sub-micron level dynamic control of the perovskite coating thickness, improving slit adjustment accuracy and die durability.

Description

Technical Field

[0001] This application relates to the field of perovskite battery production equipment technology. Background Technology

[0002] Perovskite solar cells have become a research hotspot in the photovoltaic field due to their high photoelectric conversion efficiency (>25%) and low manufacturing cost. Their core manufacturing process—slit coating technology—directly determines the uniformity and density of the perovskite active layer and functional layer, thereby affecting the performance and lifespan of the cell.

[0003] However, traditional slot coating dies face the following key challenges when used in perovskite solar cell production: 1. Insufficient coating precision and dynamic control capabilities: The thickness uniformity of perovskite films needs to be controlled at the submicron level (typically <500nm), while traditional dies rely on mechanical screws to manually adjust the slot width (adjustment accuracy ±10μm) and cannot respond to film thickness fluctuations in real time during coating. Existing publicly available dies use open-loop control, resulting in coating thickness non-uniformity as high as ±5%, making it difficult to meet the stringent requirements of perovskite layers for interface defects. 2. Prominent solvent corrosion and crystallization blockage issues: Perovskite precursor solutions often use highly polar solvents (such as DMF and DMSO solutions), which easily corrode the metal surface of the die's flow channels, causing material residue and flow channel deformation. In addition, the solution easily forms crystals (such as PbI2) at the slot outlet due to rapid solvent evaporation, leading to frequent shutdowns for cleaning and severely restricting continuous production. Existing technologies have attempted to use Teflon coatings, but their wear resistance is poor and they cannot suppress crystal formation. 3. Poor process stability due to temperature sensitivity: The viscosity of perovskite solutions is significantly affected by temperature (e.g., the viscosity of DMF solutions decreases by about 2% for every 1°C increase in temperature). Traditional dies lack temperature control modules, resulting in limited coating speed (typically <1m / min) and film thickness fluctuations with ambient temperature. Especially in large-area coating (substrate width >1m), uneven temperature distribution within the flow channel can cause lateral thickness gradients (difference between edge and center >8%). 4. Unmet needs for multilayer coating and process flexibility: Advanced perovskite cell structures (e.g., nip-type, pin-type) require continuous coating of perovskite and transport layers (e.g., Spio-OMeTAD, SnO2) in a single process. However, traditional dies are mostly single-cavity designs, unable to achieve precise interlayer alignment or simultaneous coating of heterogeneous solutions. Furthermore, laboratory R&D and small-batch pilot production require frequent changes in solution type. Disassembly of existing dies' piping takes 1-2 hours and is prone to cross-contamination due to seal failure. Summary of the Invention

[0004] The purpose of this application is to provide an adjustable slit coating die for the production of perovskite solar cells in order to solve the above-mentioned technical problems.

[0005] To achieve the above objectives, this application specifically adopts the following technical solution:

[0006] An adjustable slit coating die head for perovskite battery production includes a modular slit adjustment structure located at the working end of the coating machine. The modular slit adjustment structure includes an upper die lip and a lower die lip, with a piezoelectric ceramic driving unit disposed between them.

[0007] It also includes an online film thickness monitoring device that uses laser interferometry to measure thickness and feed back film thickness monitoring signals. The piezoelectric ceramic driving unit responds to the film thickness monitoring signals to achieve dynamic closed-loop adjustment of the slit width in the range of 50-500μm.

[0008] It also includes a compartmentalized flow channel structure, which contains at least two independent liquid supply chambers. Each chamber is equipped with a high-precision screw pump and a pressure feedback system. Each chamber is divided into several independent channels by diaphragm gaskets between the slits. The independent channels extend from each chamber to the outlet below the slit, supporting multi-layer synchronous coating. The pressure feedback system feeds back the pressure of each liquid supply chamber and adjusts the operation of the high-precision screw pump and the liquid supply pressure.

[0009] The above scheme achieves sub-micron level dynamic control of perovskite coating thickness through a modular slit adjustment structure. The piezoelectric ceramic drive unit, based on real-time feedback signals from a laser interferometry online film thickness monitoring device, precisely adjusts the gap between the upper and lower die lips, overcoming the lag of traditional manual mechanical screw adjustments and significantly reducing thickness non-uniformity. The built-in temperature control module, with its micro-thermoelectric cooler and temperature sensor forming a temperature control system, combined with the ultra-low surface energy characteristics of the DLC coating, suppresses solvent corrosion while achieving uniform flow channel temperature, thus reducing DMF solution viscosity fluctuations. The compartmentalized flow channel structure, through the collaboration of independent liquid supply chambers and a high-precision screw pump, enables synchronous heterogeneous coating of the perovskite layer and transport layer. The pressure feedback system in each chamber reduces interlayer alignment errors, meeting the requirements of various laminated structures.

[0010] Furthermore, the lower ends of the upper mold lip and the lower mold lip are provided with a knife edge buffer cavity composite structure. The knife edge buffer cavity composite structure includes a knife edge located at the lower ends of the upper mold lip and the lower mold lip, and a buffer cavity located above the knife edge. The buffer cavity is located at the lower end of the cavity-type flow channel structure. The inclination angle of the buffer cavity is 30°-60°, the depth of the buffer cavity is 3-5 times the slit width, and the chamfer radius of the knife edge is ≤10μm.

[0011] Through the above scheme, the knife-edge buffer cavity composite structure guides the fluid to form a stable and extended flow field through a 30°-60° tilt angle design. The optimized geometric parameters, with the buffer cavity depth being 3-5 times the slit width, reduce the shear rate and effectively eliminate crystal deposition caused by streamline contraction at the outlet. The nanoscale chamfer radius of ≤10μm at the knife-edge edge suppresses the pinning effect of solution wetting and spreading. Combined with the hydrophobic properties of the DLC coating, this prolongs the PbI2 crystallization formation time.

[0012] Furthermore, the miniature thermoelectric coolers of the temperature control module are distributed on both sides of the flow channel, forming a PID temperature control loop with the temperature sensor, with a temperature control accuracy of ±0.5℃ and an operating temperature range of 15-80℃.

[0013] The above solution utilizes a PID algorithm to compensate for the longitudinal temperature gradient of the flow channel, achieving a lateral temperature difference of <0.3℃ on a 1-meter-wide substrate, thus eliminating film thickness variations caused by uneven heat conduction in traditional die heads. The 0.5-2μm thick DLC coating on the inner wall of the flow channel combines high thermal conductivity with superior corrosion resistance.

[0014] Furthermore, an ultrasonic vibrating plate is integrated at the lower end outlet of the upper mold lip and the lower mold lip. The ultrasonic vibrating plate is located at the lower end of the cavity-type flow channel structure. The ultrasonic vibrating plate has a vibration frequency of 20-100kHz and a power density of 0.1-5W / cm2.

[0015] Through the above method, the ultrasonic vibrating plate generates a cavitation effect at the slit exit using high-frequency mechanical waves of 20-100kHz, disrupting the hydrogen bond network of the perovskite precursor solution and reducing the apparent viscosity of the solution. Power density: 0.1-5W / cm³ 2 Gradient control can precisely suppress the solvent evaporation rate and reduce crystallization.

[0016] Furthermore, each independent liquid supply chamber of the segmented flow channel structure is connected to the liquid supply system. The connection interface between the liquid supply system and the mold head adopts a magnetic quick-connect interface, which includes symmetrically distributed permanent magnet rings and sealing rings, and supports the switching of the liquid supply pipeline within 10 minutes.

[0017] The above solution utilizes a permanent magnet ring to generate sealing pressure, achieving a zero-leakage connection. Compared to traditional flange connections, pipeline switching time is shortened, and the magnetic self-alignment characteristic reduces cross-contamination rates during the switching of dissimilar solutions.

[0018] Furthermore, the displacement control algorithm of the piezoelectric ceramic drive unit is an adaptive PID, and its input signal comes from the laser interference data of the online film thickness monitoring device, with a feedback response time of <50ms.

[0019] Through the above scheme, the adaptive PID algorithm integrates multi-point thickness data from the laser interferometer, which speeds up the response of piezoelectric ceramics. The fast response of less than 50ms can compensate for the thickness deviation caused by substrate speed fluctuations and maintain uniformity during high-speed coating.

[0020] Furthermore, the slit width at the outlet of each independent liquid supply chamber of the segmented flow channel structure is adjustable, with an adjustment range of 50-300μm, and the spacing between adjacent slits of each independent liquid supply chamber is 1-10mm.

[0021] The above scheme achieves gradient control of the perovskite / transport layer interface by independently adjusting the width and spacing of each cavity slit.

[0022] Furthermore, it also includes a cleaning agent injection channel and an ultrasonic generator connected to the cavity-type flow channel structure, with a cleaning frequency of 20-60kHz.

[0023] The above solution utilizes 20-60kHz frequency cavitation to improve the penetration efficiency of the cleaning agent. Combined with a temperature control module, it can remove cross-linking residues in the flow channel, saving solvent consumption compared to traditional immersion cleaning and avoiding damage to the DLC coating during disassembly.

[0024] The beneficial effects of this application are as follows:

[0025] 1. Regarding coating precision, this application integrates a closed-loop control system combining piezoelectric ceramic drive and laser interferometric thickness measurement to improve slit adjustment accuracy. Combined with an adaptive PID algorithm, it achieves a 50ms-level dynamic response, significantly reducing the non-uniformity of 500nm-level ultrathin coatings and minimizing interfacial recombination losses. For corrosion resistance and anti-crystallization design, an innovative synergistic scheme of DLC coating and ultrasonic vibration is adopted. The former resists strong polar solvent erosion through a diamond-like structure, while the latter suppresses solute supersaturation through cavitation effects, extending the continuous working time of the die head and extending maintenance cycles. The temperature sensitivity challenge is overcome by combining a micro-thermoelectric cooling array with a high thermal conductivity DLC coating, reducing the thickness gradient caused by viscosity fluctuations. Simultaneously, in terms of process flexibility, the segmented flow channel and magnetic quick-connect interface enable multi-layer heterogeneous coating. Independent temperature control and slit spacing adjustment optimize the lattice matching of the perovskite / transport layer interface, while the modular design improves solution switching efficiency. Compared to traditional technologies, this solution significantly improves the mass production qualification rate of perovskite solar cells, reduces module manufacturing costs, and enhances the durability of the die head, providing key equipment support for industrialization. Attached Figure Description

[0026] Figure 1 This is a cross-sectional structural diagram of the mold head of this application, showing the flow channel, temperature module, and piezoelectric adjustment unit.

[0027] Figure 2This is a schematic diagram of the multilayer coating flow channel distribution in this application;

[0028] Figure 3 This is an enlarged view of the "blade buffer cavity" structure at the slit end of the mold head in this application;

[0029] Figure 4 This is a block diagram of the dynamic adjustment and control system of this application.

[0030] Reference numerals: 101, Upper mold lip; 102, Lower mold lip; 103, Piezoelectric ceramic drive unit; 104, Buffer chamber; 201, Miniature thermoelectric cooler; 202, Temperature sensor; 203, DLC coating; 301, Split-chamber flow channel structure; 311, Liquid supply chamber; 302, High-precision screw pump; 303, Pressure feedback system; 401, Ultrasonic vibrating plate; 501, Liquid supply system; 502, Magnetic quick-connect interface; 512, Permanent magnet ring; 522, Sealing ring; 601, Online film thickness monitoring device; 701, Cleaning agent injection channel; 702, Ultrasonic generator. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0033] Reference Figures 1 to 4 An adjustable slit coating die head for perovskite battery production includes a modular slit adjustment structure located at the working end of the coating machine. The modular slit adjustment structure consists of an upper die lip 101 and a lower die lip 102, which are connected by a piezoelectric ceramic driving unit 103. The piezoelectric ceramic driving unit 103 responds to the film thickness monitoring signal to achieve dynamic closed-loop adjustment of the slit width in the range of 50-500μm.

[0034] An online film thickness monitoring device 601 that uses laser interferometric data to measure film thickness and feeds back film thickness monitoring signals; specifically, in this embodiment, a laser interferometer is used to detect the coating thickness.

[0035] The compartmentalized flow channel structure 301 includes at least two independent liquid supply chambers 311. In this embodiment, two liquid supply chambers 311 are used. Each chamber is divided into two independent channels by a diaphragm gasket between the slits. The independent channels extend from each chamber to the outlet below the slit, thereby supporting the simultaneous coating of two layers. At the same time, by adding liquid supply chambers 311 and matching diaphragm gaskets, multi-layer coating can be achieved. Each chamber is equipped with a high-precision screw pump 302 and a pressure feedback system 303. The pressure feedback system 303 provides various sensors to realize pressure monitoring, supports the simultaneous coating of perovskite layer and transport layer, and provides feedback on the pressure of each liquid supply chamber 311 and adjusts the operation of the high-precision screw pump 302 and the liquid supply pressure.

[0036] The built-in temperature control module includes a miniature thermoelectric cooler 201 embedded inside the mold head, a temperature sensor 202, and a DLC coating 203. The DLC coating 203 covers the inner wall of the channel of the cavity-type flow channel structure 301 with a thickness of 0.5-2μm.

[0037] Submicron-level dynamic control of perovskite coating thickness is achieved through a modular slit adjustment structure. The piezoelectric ceramic drive unit 103, based on real-time feedback signals from the laser interferometry online film thickness monitoring device 601, precisely adjusts the spacing between the upper die lip 101 and the lower die lip 102, overcoming the lag of traditional manual adjustment with mechanical screws and significantly reducing thickness non-uniformity. In the built-in temperature control module, a micro thermoelectric cooler 201 and a temperature sensor 202 constitute a temperature control system. Combined with the ultra-low surface energy characteristics of the DLC coating 203, it suppresses solvent corrosion while adjusting the flow channel temperature uniformity through the built-in temperature control module, thus reducing DMF solution viscosity fluctuations. The compartmentalized flow channel structure 301, through the collaboration of an independent liquid supply chamber 311 and a high-precision screw pump 302, achieves synchronous heterogeneous coating of the perovskite layer and the transport layer. The pressure feedback system 303 of each chamber reduces interlayer alignment errors, meeting the requirements of various stacked structures.

[0038] Reference Figures 1 to 4The lower ends of the upper die lip 101 and the lower die lip 102 are provided with a knife-edge buffer cavity composite structure, including a knife edge at the lower end of the upper die lip 101 and the lower die lip 102 and a buffer cavity 104 located above the knife edge. The buffer cavity 104 is located on the split-cavity flow channel structure 301. The inclination angle of the buffer cavity 104 is 30°-60°, the depth of the buffer cavity 104 is 3-5 times the slit width, and the chamfer radius of the knife edge is ≤10μm. The knife-edge buffer cavity composite structure guides the fluid to form a stable and extended flow field through the 30°-60° inclination angle design. The optimized geometric parameters of the buffer cavity 104 depth being 3-5 times the slit width reduce the shear rate and effectively eliminate crystal deposition caused by streamline contraction at the outlet. The nanoscale chamfer radius of the knife edge ≤10μm suppresses the pinning effect of solution wetting and spreading. Combined with the hydrophobic properties of the DLC coating 203, the PbI2 crystallization formation time is extended.

[0039] Reference Figures 1 to 4 The miniature thermoelectric coolers 201 of the temperature control module are distributed on both sides of the slit channel, forming a PID temperature control loop with the temperature sensor 202. The temperature control accuracy is ±0.5℃, and the operating temperature range is 15-80℃. By compensating for the longitudinal temperature gradient of the channel through a PID algorithm, a transverse temperature difference of <0.3℃ is achieved on a 1-meter-wide substrate, eliminating film thickness differences caused by uneven heat conduction in traditional molds. The 0.5-2μm thick DLC coating 203 on the inner wall of the channel combines high thermal conductivity with superior corrosion resistance.

[0040] Reference Figures 1 to 4 An ultrasonic vibrating element 401 is integrated at the lower outlet of the upper mold lip 101 and the lower mold lip 102. The ultrasonic vibrating element 401 is located at the lower end of the cavity-type flow channel structure 301. The ultrasonic vibrating element 401 has a vibration frequency of 20-100kHz and a power density of 0.1-5W / cm². 2 The ultrasonic vibrator 401 generates a cavitation effect at the slit exit using high-frequency mechanical waves of 20-100kHz, disrupting the hydrogen bond network of the perovskite precursor solution and reducing the apparent viscosity of the solution. Power density: 0.1-5 W / cm³ 2 Gradient control can precisely suppress the solvent evaporation rate and reduce crystallization.

[0041] Reference Figures 1 to 4 The connection interface between the liquid supply system 501 and the die head adopts a magnetic quick-connect interface 502. Each independent liquid supply chamber 311 of the compartmentalized flow channel structure 301 is connected to the liquid supply system 501. The connection interface between the die heads is connected to each independent liquid supply chamber 311 through pipelines. The magnetic quick-connect interface 502 includes symmetrically distributed permanent magnet rings 512 and sealing rings 522, supporting liquid supply pipeline switching within 10 minutes. The permanent magnet rings 512 generate sealing pressure to achieve zero-leakage connection. Compared with traditional flange connections, pipeline switching time is shortened, and the magnetic self-alignment characteristic reduces the cross-contamination rate when switching heterogeneous solutions.

[0042] Reference Figures 1 to 4 The displacement control algorithm of the piezoelectric ceramic driving unit 103 is an adaptive PID, and its input signal comes from the laser interferometric data of the online film thickness monitoring device 601, with a feedback response time of <50ms. The adaptive PID algorithm integrates multi-point thickness data from the laser interferometer, which speeds up the response of the piezoelectric ceramic driving unit 103. The fast response of <50ms can compensate for the thickness deviation caused by substrate speed fluctuations, and maintain uniformity even during high-speed coating.

[0043] Reference Figures 1 to 4 The slit width at the outlet of each independent liquid supply chamber 311 in the compartmentalized flow channel structure 301 is adjustable. This adjustment is achieved through a piezoelectric ceramic drive unit 103 located at the outlet. Simultaneously, a diaphragm gasket ensures that each channel does not interfere with the others. The adjustment range is 50-300 μm, and the spacing between adjacent slits in each independent liquid supply chamber 311 is 1-10 mm. The diaphragm gasket has the ability to maintain a certain shape, thus facilitating the adjustment of the slit spacing via the piezoelectric ceramic drive unit 103. By independently adjusting the slit width and spacing of each chamber, gradient control of the perovskite / transport layer interface is achieved.

[0044] Reference Figures 1 to 4 It also includes a cleaning agent injection channel 701 connected to the chambered flow channel structure 301 and an ultrasonic generator 702, with a cleaning frequency of 20-60kHz. Through the cavitation effect of the 20-60kHz frequency conversion, the penetration efficiency of the cleaning agent is improved. With the help of the temperature control module, cross-linking residues in the flow channel can be removed. Compared with traditional immersion cleaning, it saves solvent consumption and avoids damage to the DLC coating 203 during disassembly.

[0045] This application also provides a perovskite solar cell manufacturing process based on the aforementioned slit coating die, comprising the following steps:

[0046] Step S1: Connect the perovskite precursor liquid supply system 501 via the magnetic quick-connect interface 502;

[0047] Step S2: Set the initial slit width of the cavity-type flow channel structure 301 and adjust the liquid supply temperature through the built-in temperature control module. Start the coating machine and collect film thickness data in real time through the online film thickness monitoring device 601.

[0048] Step S3: The piezoelectric ceramic drive unit 103 dynamically adjusts the slit width based on the film thickness deviation collected by the online film thickness monitoring device 601, and simultaneously adjusts the liquid supply pressure through the high-precision screw pump 302 and the pressure feedback system 303 until the coating uniformity is ≤ ±1.5%.

[0049] Step S4: Apply at least one coating layer. After coating is completed, switch to ultrasonic cleaning mode. The cleaning agent injection channel 701 and ultrasonic generator 702 realize cleaning agent injection and ultrasonic cleaning to remove residual solution from the flow channel.

[0050] By employing multi-parameter closed-loop control of film thickness, slit size, and pressure, and integrating a closed-loop control system combining piezoelectric ceramic drive and laser interferometry thickness measurement, the slit adjustment precision is improved. Combined with an adaptive PID algorithm, a 50ms-level dynamic response is achieved, significantly reducing the non-uniformity of 500nm-level ultrathin coatings and minimizing interfacial recombination losses. For corrosion resistance and anti-crystallization design, an innovative synergistic solution of DLC coating 203 and ultrasonic vibration is adopted. The former resists strong polar solvent erosion through a diamond-like structure, while the latter suppresses solute supersaturation through cavitation effects, extending the continuous working time of the die head and extending maintenance cycles. The temperature sensitivity challenge is overcome by combining a micro-thermoelectric cooling array with the high thermal conductivity DLC coating 203, reducing the thickness gradient caused by viscosity fluctuations. Simultaneously, in terms of process flexibility, the compartmentalized flow channel structure 301 and magnetic quick-connect interface 502 enable multi-layer heterogeneous coating. Independent temperature control and slit spacing adjustment optimize the lattice matching of the perovskite / transport layer interface, while modular design improves solution switching efficiency. Compared to traditional technologies, this solution significantly improves the mass production qualification rate of perovskite solar cells, reduces module manufacturing costs, and enhances the durability of the die head, providing key equipment support for industrialization.

[0051] Furthermore, when performing double-layer coating, the temperature difference of the solution in the two liquid supply chambers 311 is controlled between 5-30℃, and the coating speed difference is ≤0.3m / min.

[0052] Example 1: Coating of perovskite light-absorbing layer (single-layer narrow-width process)

[0053] Application scenario: Laboratory research and development, with a 10cm×10cm glass substrate coated with MAPbI 3 precursor solution (DMF solution, concentration 40wt%).

[0054] Operating steps:

[0055] 1. Die head pretreatment:

[0056] Connect the DMF solution supply line via the magnetic quick-connect interface 502, and start the ultrasonic generator 702 of the self-cleaning module (frequency 40kHz, power 3W / cm²). 2 ) And switch the isopropanol line through the magnetic quick-connect interface 502 to inject isopropanol to clean the flow channel for 5 minutes;

[0057] Set the flow channel temperature to 25°C via the built-in temperature control module and preheat for 10 minutes to stabilize the temperature.

[0058] 2. Dynamic coating control:

[0059] The initial slit width was set to 150 μm, and the coating speed was 0.5 m / min;

[0060] Start online film thickness monitoring (laser interferometer, sampling frequency 100Hz), and collect film thickness data in real time through online film thickness monitoring device 601;

[0061] When a film thickness deviation >1.5% is detected (e.g., 280nm in the center and 320nm at the edge), the piezoelectric ceramic drive unit 103 automatically adjusts the slit to 155μm and simultaneously adjusts the liquid supply pressure from 0.2MPa to 0.22MPa, restoring uniformity to ±1.2% within 10 seconds.

[0062] 3. Anti-crystallization maintenance:

[0063] After coating is completed, switch to ultrasonic anti-clogging mode and start ultrasonic vibrator 401 (ultrasonic vibrator 401 frequency 60kHz, power density 2W / cm2) for 3 minutes to prevent residual DMF solution from crystallizing.

[0064] Connect the switching nitrogen pipeline via the magnetic quick-connect interface 502, use nitrogen to purge the flow channel, and the residual solution volume is <0.1μL / cm2 (traditional mold head >1μL / cm2).

[0065] The technical effects of the mold head in this application:

[0066] Thickness non-uniformity decreased from ±5.8% to ±1.2%;

[0067] The number of crystallization blockages per hour is less than 2;

[0068] The time required for a single cleaning session has been reduced from 30 minutes to 8 minutes.

[0069] Example 2: Perovskite / electron transport layer double-layer coating (roll-to-roll mass production)

[0070] Application scenarios: GW-level production lines, flexible PET substrate (1.2m width), simultaneous coating of MAPbI 3 layers (calcium-titanium liquid supply chamber 311) and SnO2 electron transport layer (SnO2 colloidal liquid supply chamber 311).

[0071] Operating steps:

[0072] 1. Process parameter preset:

[0073] Perovskite supply chamber 311: Perovskite solution, temperature 25℃, slit width 200μm, coating speed 3m / min;

[0074] SnO2 colloid supply chamber 311: SnO2 colloidal solution (water-alcohol solvent), temperature 35℃, slit width 80μm, coating speed 3.2m / min;

[0075] The distance between the two slits is set to 5mm (with an error of ±0.1mm).

[0076] 2. Collaborative control:

[0077] The temperature module independently controls the viscosity of the solutions in both chambers (the temperature of the calcium titanium supply chamber 311 is 25℃±0.5℃, and the temperature of the SnO2 colloid supply chamber 311 is 35℃±0.5℃).

[0078] The piezoelectric ceramic drive unit 103 synchronously adjusts the slit spacing of the calcium titanium liquid supply chamber 311 and the SnO2 colloidal liquid supply chamber 311 according to the film thickness feedback data from the online film thickness monitoring device 601. Specifically, the calcium titanium liquid supply chamber 311 is 200→205μm, and the SnO2 colloidal liquid supply chamber 311 is 80→78μm to compensate for the thickness deviation caused by the tension fluctuation of the substrate.

[0079] 3. Continuous production validation:

[0080] After running continuously for 48 hours, the following test was performed:

[0081] Perovskite layer thickness: 320±5nm;

[0082] SnO2 layer thickness: 50±1nm;

[0083] No crystallization blockage alarm, and no visible corrosion on the inner surface of the die head slit.

[0084] Multi-layer coating is achieved by setting diaphragm gaskets, and the slit spacing at the lower end is 5mm to prevent the two solutions from mixing (capillary permeation occurs when the spacing is <3mm).

[0085] Example 3: Coating with a highly corrosive solution (DMSO-based hole transport layer)

[0086] Application scenario: Coating the die head with a DMSO solution of Spio-OMeTAD (pH=4.5, strongly acidic) to verify the corrosion resistance of the die head.

[0087] The operating steps are the same as in Example 1.

[0088] 1. Corrosion resistance test:

[0089] After 200 hours of continuous operation, the inner wall of the flow channel was inspected using a white light interferometer: the DLC coating 203 showed no peeling (the traditional Teflon coating showed localized peeling);

[0090] Surface roughness a < 0.05 μm (initial value a = 0.03 μm).

[0091] Example 4: Rapid Changeover Process (Laboratory Multi-Material R&D)

[0092] Scenario: Switching between coating perovskite (DMF solution), PCBM (chlorobenzene), and PEDOT:PSS (aqueous solution) using the same die head.

[0093] The specific coating operation steps are the same as in Example 1:

[0094] 1. DMF solution → Chlorobenzene conversion:

[0095] Disconnecting the magnetic quick-connect interface 502 and replacing the chlorobenzene supply line took 3 minutes.

[0096] Initiate ultrasonic cleaning (frequency 50kHz) + nitrogen purging for 5 minutes, residual DMF solution concentration <10ppm.

[0097] 2. Chlorobenzene → PEDOT:PSS conversion:

[0098] A two-step cleaning method is used:

[0099] Switch the ethanol line using the magnetic quick-connect interface 502 and flush with ethanol for 5 minutes to remove chlorobenzene residue;

[0100] Then use the magnetic quick-connect interface 502 to switch the water supply pipeline and flush with deionized water for 5 minutes to avoid the water solution from being miscible with organic solvents;

[0101] The total replacement time is 12 minutes, and the cross-contamination rate is <0.01%.

[0102] 3. Process scalability:

[0103] 1. By increasing or decreasing the number of 311 sub-chambers in the liquid supply chamber (supporting up to 4 layers of coating), it can be adapted to the production of perovskite-silicon tandem solar cells.

[0104] 2. Replace with the magnetic quick-connect interface 502 adapter, compatible with various common types of liquid supply systems 501 on the market.

[0105] It should be noted that the connection relationships of components not specifically mentioned in this application are all assumed to be based on existing technology. Since they do not involve the inventive point and are commonly used in existing technology, the structural connection relationships are not described in detail.

Claims

1. An adjustable slit coating die for perovskite solar cell production, characterized in that, The invention includes a modular slit adjustment structure located at the working end of the coating machine. The modular slit adjustment structure includes an upper die lip (101) and a lower die lip (102), which form a slit between them. Several piezoelectric ceramic drive units (103) are provided in the slit. It also includes an online film thickness monitoring device (601) that uses laser interferometry to measure thickness and feeds back film thickness monitoring signals. The piezoelectric ceramic driving unit (103) responds to the film thickness monitoring signals to achieve dynamic closed-loop adjustment of the slit width in the range of 50-500μm. It also includes a compartmentalized flow channel structure (301), which includes at least two independent liquid supply chambers (311). Each chamber is equipped with a high-precision screw pump (302) and a pressure feedback system (303). Each chamber is divided into several independent channels by setting a diaphragm gasket between the slits. The independent channels extend from each chamber to the outlet below the slit, supporting multi-layer synchronous coating. The pressure feedback system (303) feeds back the pressure of each liquid supply chamber (311) and adjusts the operation of the high-precision screw pump (302) and the liquid supply pressure.

2. The adjustable slit coating die head for perovskite battery production according to claim 1, characterized in that, The lower ends of the upper die lip (101) and the lower die lip (102) are provided with a composite structure of cutting edge and buffer cavity, including a cutting edge at the lower ends of the upper die lip (101) and the lower die lip (102) and a buffer cavity (104) located above the cutting edge. The buffer cavity (104) is located at the lower end of the cavity-type flow channel structure (301). The inclination angle of the buffer cavity (104) is 30°-60°. The depth of the buffer cavity (104) is 3-5 times the slit width, and the chamfer radius of the cutting edge is ≤10μm.

3. The adjustable slit coating die head for perovskite battery production according to claim 1, characterized in that, The device includes a built-in temperature control module, which comprises a miniature thermoelectric cooler (201), a temperature sensor (202), and a DLC coating (203) embedded inside the upper mold lip (101) and the lower mold lip (102). The DLC coating (203) covers the inner wall of the flow channel of the cavity-type flow channel structure (301). The miniature thermoelectric cooler (201) of the temperature control module is distributed on both sides of the cavity-type flow channel structure (301). The miniature thermoelectric cooler (201) and the temperature sensor (202) form a PID temperature control loop with a temperature control accuracy of ±0.5℃ and an operating temperature range of 15-80℃.

4. The adjustable slit coating die head for perovskite battery production according to claim 1, characterized in that, An ultrasonic vibrating plate (401) is integrated at the lower end outlet of the upper mold lip (101) and the lower mold lip (102). The ultrasonic vibrating plate (401) is located on the cavity-type flow channel structure (301). The ultrasonic vibrating plate (401) has a vibration frequency of 20-100kHz and a power density of 0.1-5W / cm2.

5. An adjustable slit coating die for perovskite battery production according to claim 1, characterized in that, Each independent liquid supply chamber (311) of the compartmentalized flow channel structure (301) is connected to the liquid supply system (501). The connection interface between the liquid supply system (501) and each liquid supply chamber (311) adopts a magnetic quick-connect interface (502). The magnetic quick-connect interface (502) includes symmetrically distributed permanent magnet rings (512) and sealing rings (522).

6. An adjustable slit coating die for perovskite solar cell production according to claim 1, characterized in that, The displacement control algorithm of the piezoelectric ceramic drive unit (103) is an adaptive PID, and its input signal comes from the laser interference data of the online film thickness monitoring device (601), with a feedback response time of <50ms.

7. An adjustable slit coating die for perovskite battery production according to claim 1, characterized in that, The slit width at the outlet of each independent liquid supply chamber (311) of the compartmentalized flow channel structure (301) is adjustable, with an adjustment range of 50-300μm, and the distance between adjacent slits of each independent liquid supply chamber (311) is 1-10mm.

8. An adjustable slit coating die for perovskite battery production according to claim 1, characterized in that, It also includes a cleaning agent injection channel (701) connected to the cavity-type flow channel structure (301) and an ultrasonic generator (702), the ultrasonic generator (702) having a cleaning frequency of 20-60kHz.

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