Perovskite solution slit coating device and method

Abstract

The invention relates to a perovskite solution slit coating device and method. The device comprises a die head I, a die head II and a gasket which is arranged between the die head I and the die head II and is used for forming a coating solution runner. A flow collecting groove is formed in the first die head, and a liquid injection opening is formed in the bottom of the flow collecting groove. The body of the gasket and the two side arms can surround the flow collecting groove in the middle. An opening is formed in an open region between the facing surfaces of the margin plates on the side arms. And an extension body which can be inserted into the flow collecting groove is formed on the body and between the two side arms. A first part of the extension body vertically extends relative to the body, a second part of the extension body parallelly extends relative to the body, the first part is in contact with the opposite surfaces of the flow collecting groove, and a spacing area is formed between the second part and the inner bottom surface of the flow collecting groove. And the liquid injection port corresponds to the middle position of the second part in the width direction. According to the invention, the quality of a film layer prepared by coating can be improved, so that the uniformity condition of film thickness is obviously improved.

Description

Technical Field

[0001] This invention belongs to the field of slot coating technology, specifically relating to a slot coating device and method for perovskite solutions. Background Technology

[0002] Slot coating is a commonly used coating process. Its principle is to force the coating solution through a slot / channel formed by the mating parts of a mold under certain pressure, covering a moving substrate. It features fast coating speed, good coating uniformity, and a wide coating window. In the production of perovskite solar cells, coating technology is commonly used to coat the perovskite solution onto the substrate. Commonly used coating processes / methods include spin coating, blade coating, and inkjet printing. While spin coating can obtain relatively uniform films, it has low material utilization and is not suitable for large-area solar panel fabrication, exhibiting significant limitations. Blade coating (translational coating), although usable for large-area solar panel production, results in poor film thickness uniformity (the film thickness formed after the perovskite solution dries), and the wider the manufactured solar panel, the more significant the film thickness non-uniformity. Uneven coating thickness affects the overall quality of the coating layer, which in turn affects the quality of perovskite solar panels, becoming one of the factors restricting further improvement in the photoelectric conversion efficiency and stability of perovskite solar cells. Therefore, when producing large-area cells (panels), it is urgent to improve the slit coating device to overcome the problems of low film quality and unstable uniformity and flatness of film thickness across the width.

[0003] During production, it was found that because the injection ports connected to the flow channels on the die head are mostly located in the middle of the flow channel's width, the coating solution injected into the flow channel often has a higher loading rate at the center and a relatively lower loading rate towards the sides. This negatively affects the uniformity of the film thickness formed in the width direction of the die head. Summary of the Invention

[0004] To achieve the above objectives, the present invention provides a perovskite solution slit coating apparatus and method, which can improve the quality of the coated film and significantly improve the uniformity of the film thickness.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a perovskite solution slot coating device, including a first mold head, a second mold head, and a gasket disposed between the two opposite surfaces to form a coating solution flow channel.

[0006] A flow collection groove is formed on the surface of the first mold head facing the second mold head, and an injection port is formed at the bottom of the flow collection groove.

[0007] The gasket includes a body and side arms formed on both sides of the body's width. The body and the two side arms enclose the manifold in the middle. Opposing flanges are formed at the free ends of the two side arms, and the open area between the opposing surfaces of the two flanges forms an opening. The coating solution can flow from the opening to the outside of the die head and coat the substrate / base plate. The width of the opening is the width of the coated film.

[0008] An L-shaped extension is formed on the main body, between the two side arms. The first part of the extension extends perpendicularly to the main body, and the second part extends parallel to the main body.

[0009] The extension body can be inserted into the collecting trough, with the first part contacting the opposing surfaces of the collecting trough, and a gap area formed between the second part and the inner bottom surface of the collecting trough. The injection port is located at the center of the width of the second part.

[0010] Optionally, the opening of the collecting channel is rectangular, and the extension length of the extension body is consistent with the length of the opening of the collecting channel.

[0011] Optionally, the extension body and the gasket body are integrally molded structures, which can ensure that the connection between the two and the extension body itself have sufficient strength.

[0012] Optionally, a settling trough is formed on the side of the second part facing the bottom of the collecting trough. The lower surface of the settling trough extends downwards to both sides from the center of the second part to form an inclined plane, and the extension lines of the two inclined planes at their adjacent ends can intersect.

[0013] Optionally, a sinkhole is formed near the root of the second part. A stepped portion is formed on the free side of the second part, and the sinkhole and the stepped portion are on the same plane, such that the thickness of the free end of the second part is less than the thickness of its main body.

[0014] Optionally, a protruding ridge is formed on the side of the second part facing the bottom surface of the collecting trough. The top surface of the protruding ridge is formed into a downwardly sloping surface extending to both sides from the center of the second part. After the extension body extends into the collecting trough, the liquid injection port is positioned above the center of the top surface of the protruding ridge.

[0015] Optionally, a vertical gap is formed between the lower end face / bottom face of the protruding ridge and the free end face of the second part.

[0016] Optionally, multiple channels are provided on the convex ridge, corresponding to the central position of the second part and alternating on both sides of the central position. All channels are vertically continuous and have a cross-section that is trapezoidal with the short side facing upwards.

[0017] Optionally, the width of the upper port of the channels distributed from the center to both sides increases in a stepped manner.

[0018] This application also relates to a perovskite solution slot coating method, which relies on any of the above-mentioned perovskite solution slot coating devices. Its characteristic is that it can block the space where the injection port is located in the collection tank by means of the set extension body, thereby reducing the amount of coating solution loaded at the central position of the (drill head) and increasing the amount of coating solution distributed to both sides of the width of the (drill head).

[0019] The beneficial effects of this invention are: it improves the film thickness quality formed by the perovskite solution coated on the substrate, significantly improving the uniformity of the film thickness obtained in production, thus creating favorable conditions for improving the quality, photoelectric conversion efficiency, and stability of perovskite solar cells. Specifically, the technical solution of this application optimizes the distribution of the coating solution between the central and lateral positions, making the loading of the coating solution in the width direction of the die more uniform, thereby improving the uniformity of the film thickness obtained in the coating process. Attached Figure Description

[0020] Figure 1 This is a cross-sectional structural diagram of Embodiment 1 of this application.

[0021] Figure 2 for Figure 1 A magnified schematic diagram of the structure at point A in the middle.

[0022] Figure 3 This is a schematic diagram of the gasket's main view structure.

[0023] Figure 4 This is a schematic diagram of the axial structure of the gasket.

[0024] Figure 5 This is a schematic diagram of the structure of Embodiment 2 of this application.

[0025] Figure 6 for Figure 5 A magnified schematic diagram of the structure at point B in the middle.

[0026] Figure 7 This is a schematic diagram of the gasket structure in Example 2 from the main view.

[0027] In the diagram: 10 Die head one, 11 Collection groove, 12 Injection port; 20 Die head two; 30 Gasket, 31 Side arm, 311 Edge plate, 32 Extension body, 321 First part, 322 Second part, 323 Settling tank, 324 Stepped section, 325 Protruding ridge, 3251 Channel, 1 Inclined surface one, 2 Inclined surface two; 40 Coating solution flow channel; 50 Spacing area. Detailed Implementation

[0028] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "upper," "lower," "front," "rear," and "middle" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0029] like Figures 1 to 7 A perovskite solution slot coating apparatus is shown, comprising a first die 10, a second die 20, and a gasket 30 disposed between their opposing surfaces to form a coating solution channel 40 (i.e., a slot). A flow collecting groove 11 is formed on the first die 10, on its surface facing the second die 20, and an injection port 12 is formed at the bottom of the flow collecting groove 11. The first die 10 and the second die 20 are detachably connected by multiple bolts / studs, allowing the gasket 30 to be fixedly clamped between their opposing surfaces, forming a slot at the lower part of the opposing surfaces of the two dies, thus forming the coating solution channel 40. By replacing the gasket 30 with gaskets of different thicknesses, the spacing of the slot formed between the two dies can be adjusted, i.e., the thickness of the coating solution channel 40 can be adjusted.

[0030] After the coating solution is fed into the channel communicating with the injection port 12, it can flow into the collection tank 11 through the injection port 12, and flow from the opening of the collection tank 11 to the slit / coating solution flow channel 40, and finally flow out from the lower opening of the coating solution flow channel 40, and be coated on the substrate / substrate.

[0031] The gasket 30 includes a body and side arms 31 formed on both sides of the body in the width direction. The body and the two side arms 31 form a U-shaped structure and can surround the collection groove 11 in the middle. At the free ends of the two side arms 31, opposing edge plates 311 are formed, and the open area between the opposing surfaces of the two edge plates 311 forms an opening, the width of which is the width of the coating solution film.

[0032] Since the above technical content can be implemented and improved with reference to existing technologies, it will not be elaborated further.

[0033] In the technical solution of this application, an L-shaped extension 32 is formed on the main body, between the two side arms 31. The first portion 321 of the extension 32 is connected to the main body and extends perpendicularly to the main body. The second portion 322 of the extension 32 is connected to the first portion 321 and extends parallel to the main body.

[0034] The extension 32 can be inserted into the collection groove 11, and the opposing surfaces of the first part 321 and the collection groove 11 are in contact. A gap area 50 is formed between the second part 322 and the inner bottom surface of the collection groove 11. The port of the injection port 12 is located on the outer side of the center of the width of the second part 322.

[0035] After the extension body 32 is provided on the body of the gasket 30, the external space of the injection port 12 is reduced, the internal pressure of the coating solution flowing from the injection port 12 into the collection tank 11 is increased, and the coating solution is forced to split from the center to both sides, thereby reducing the loading amount of the coating solution in the center and increasing the amount of coating solution split to both sides. This also makes the uniformity of the coating solution splitting in the width direction (drill head) more even, which helps to prevent the loading amount at any point in the center and on both sides from being significantly increased relative to other points. It also makes it easier to control the loading profile of the coating film in the width direction, thereby improving the uniformity of film thickness (in the width direction of the die head).

[0036] The opening of the flow collecting groove 11 is rectangular, and the extension length of the extension body 32 (which is consistent with the width of the mold head in the extension direction) is consistent with the length of the opening of the flow collecting groove 11.

[0037] like Figures 1 to 4 As shown, a settling groove 323 is formed on the side of the second portion 322 facing the inner bottom surface of the collecting trough 11. The lower groove surface of the settling groove 323 extends downwards to both sides from the central position (i.e., the OO position) of the second portion 322, so that the width of the settling groove 232 gradually increases from the central position to both sides. The angle between the (inclined) extension direction of the lower groove surface of the settling groove 323 and the horizontal direction is between 8 degrees and 30 degrees.

[0038] After the coating solution flows into the upper part of the spacing area 50 from the injection port 12, the narrow width of the spacing area 50 increases the internal pressure of the coating solution, creating an internal driving force for the solution to disperse and flow. At the same time, with the help of the two inclined surfaces at the bottom of the settling tank 323, the coating solution can be divided into two main diversion flows on both sides and, under the action of gravity, flow towards the lower port of the spacing area 50, eventually entering the coating solution flow channel 40. This fully fills the entire width of the coating solution flow channel 40, ensuring that sufficient coating solution is evenly distributed in the width direction of the opening. Therefore, after setting the settling tank 323, the diversion effect of the coating solution to both sides can be further improved, thereby improving the uniformity of the distribution of the coating solution in the width direction of the opening.

[0039] The settling groove 323 is formed near the root of the second portion 322, and a stepped portion 324 is formed on the free side of the second portion 322, such that the thickness of the main body of the second portion 322 is greater than the thickness of the outer side of the stepped portion 324. The settling groove 323 and the stepped portion 324 are on the same plane, which increases the vertical spacing of the spacing region 50 at its port, thereby increasing the flow rate of the coating solution at the port (cross-section) of the spacing region 50. This effectively prevents clogging, ensures smooth downward flow of the coating solution, and helps to ensure sufficient and stable amount of coating solution flowing into the coating solution channel 40, guaranteeing the uniformity and stability of the film thickness. Specifically, the stepped portion 324 is formed on the free side of the second portion 322, and the settling groove 323 and the stepped portion 324 are on the same plane, making the thickness of the free end of the second portion 322 less than the thickness of the main body of the second portion 322.

[0040] like Figures 5 to 7 As shown, a protruding ridge 325 is formed on the side of the second part 322 facing the bottom surface of the collection channel 11. The top surface of the protruding ridge 325 is formed into a downwardly sloping surface extending to both sides from the center position (i.e., the OO position) of the second part 322, namely sloping surface 1 and sloping surface 2 shown in the figure. The angle between the (sloping) extension direction of the top surface of the protruding ridge 325 and the horizontal direction is between 8 degrees and 30 degrees. After the extension body 32 extends into the collection channel 11, the liquid injection port 12 is positioned above the center position of the top surface of the protruding ridge 325.

[0041] After the coating solution flows into the upper part of the spacing area 50 from the injection port 12, it will be blocked by the protruding ridge 325, which will increase the internal pressure and form the internal force for the solution to disperse and flow. At the same time, with the help of the guiding (dispersing) effect of the inclined surface 1 and the inclined surface 2, the coating solution can be divided into two main diverting flows on both sides, and under the action of gravity, they flow towards the lower port of the spacing area 50, and finally enter the coating solution flow channel 40. This can fully fill the entire width of the coating solution flow channel 40, ensuring that sufficient coating solution is evenly distributed in the width direction of the opening. Therefore, after setting the protruding ridge 325, the diversion effect of the coating solution to both sides can be further improved, thereby improving the uniformity of the distribution of the coating solution in the width direction of the opening.

[0042] A vertical gap is formed between the lower end face / bottom face of the protruding ridge 325 and the free end face of the second part 322.

[0043] To facilitate better downward flow of the coating solution, ensuring sufficient filling of the entire coating solution channel 40 across its width, and improving the uniformity of the coating solution distribution across the width of the opening, thereby guaranteeing sufficient film thickness and good uniformity, multiple channels 3251 are alternately distributed on the protruding ridge 325 at the central position of the second portion 322 and on both sides of the central position. Each channel 3251 is vertically continuous and has a trapezoidal cross-section with the shorter side facing upwards. The width of the upper ports of the channels 3251 distributed from the central position (i.e., position OO) towards both sides exhibits a stepped increase trend.

[0044] To ensure that the pressure of the coating solution can be released in a timely manner and that it can flow and disperse slowly, the following measures are taken: Figure 2 , Figure 6 It can be seen that the width of the upper part of the spacing area 50 (near the height of the injection port 12, the same below) when the convex ridge 325 is set is significantly greater than the width of the upper part of the spacing area 50 when the set sink 323 is set.

[0045] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Many aspects of the present invention can be improved without departing from the overall concept. Those skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A perovskite solution slot coating device, comprising a first die (10), a second die (20) and a gasket (30) arranged between the first die (10) and the second die (20) to form a coating solution flow channel (40); a collecting groove (11) is formed on the first die (10) and on the side of the first die (10) facing the second die (20); a liquid injection port (12) is formed at the bottom of the collecting groove (11); the gasket (30) comprises a body and side arms (31) respectively formed on both sides of the body; the body and the two side arms (31) can surround the collecting groove (11) in the middle; opposite edge plates (311) are formed at the free ends of the two side arms (31), and the open area between the opposite faces of the two edge plates (311) is formed as an opening; characterized in that: An L-shaped extension body (32) is formed on the body and between the two side arms (31); a first part (321) of the extension body (32) extends perpendicularly relative to the body, and a second part (322) of the extension body (32) extends parallel relative to the body; the extension body (32) can be inserted into the current collecting groove (11), and the first part (321) is in contact with the opposite surface of the current collecting groove (11), and the second part (322) forms a spacing area (50) with the inner bottom surface of the current collecting groove (11); the liquid injection port (12) is correspondingly arranged at the central position of the width of the second part (322).

2. The perovskite solution slot-coating apparatus according to claim 1, characterized by: The slot of the current collecting groove (11) is rectangular, and the extension length of the extension body (32) is consistent with the slot length of the current collecting groove (11).

3. The perovskite solution slot-coating apparatus according to claim 1, characterized by: The extension body (32) and the body of the gasket (30) are integrally formed.

4. The perovskite solution slot-coating apparatus according to claim 1, characterized by: A sink (323) is formed on the side surface of the second part (322) facing the inner bottom surface of the current collecting groove (11); the lower groove surface of the sink (323) extends downward on both sides at the central position of the second part (322).

5. The perovskite solution slot-coating apparatus according to claim 4, characterized by: The sink (323) is formed at the root of the second part (322); a stepped portion (324) is formed on the free side of the second part (322), and the sink (323) and the stepped portion (324) are on the same surface, so that the thickness of the free end of the second part (322) is smaller than the thickness of the main body.

6. The perovskite solution slot-coating apparatus according to claim 1, characterized by: A convex rib (325) is formed on the side surface of the second part (322) facing the inner bottom surface of the current collecting groove (11); the top surface of the convex rib (325) is formed as an inclined surface extending downward on both sides at the central position of the second part (322); after the extension body (32) extends into the current collecting groove (11), the liquid injection port (12) can be correspondingly arranged above the central position of the top surface of the convex rib (325).

7. The perovskite solution slot-coating apparatus according to claim 6, characterized by: A vertical spacing is formed between the lower end surface of the convex rib (325) and the free end surface of the second part (322).

8. The perovskite solution slot-coating apparatus according to claim 6, characterized by: A plurality of grooves (3251) are arranged on the convex rib (325) and correspond to the central position of the second part (322) and are distributed on both sides of the central position; the grooves (3251) all pass through in the vertical direction, and the cross section is a trapezoid with the short side on top.

9. The perovskite solution slot-coating apparatus according to claim 8, characterized by: The upper port width of the grooves (3251) arranged on both sides from the central position has a gradient change trend.

10. The perovskite solution slot coating method of the perovskite solution slot coating apparatus according to any one of claims 1 to 9, characterized by: The position space of the liquid injection port (12) in the current collecting groove (11) can be blocked by the arranged extension body (32), so as to realize the purpose of reducing the coating solution loading amount at the central position and increasing the loading amount on both sides of the width.

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