CN115502032A

CN115502032A - Slit type coating die head for perovskite solution and coating machine thereof

Info

Publication number: CN115502032A
Application number: CN202110630279.1A
Authority: CN
Inventors: 不公告发明人
Original assignee: Quzhou Xianna New Energy Technology Co ltd
Current assignee: Quzhou Xianna New Energy Technology Co ltd
Priority date: 2021-06-07
Filing date: 2021-06-07
Publication date: 2022-12-23

Abstract

The invention relates to a slit type coating die head for perovskite solution, which comprises a left die head and a right die head which are fixed together through bolts, and is characterized in that the bottoms of the left die head and the right die head are provided with protruded die lip parts, the middle part of the die lip parts is provided with a liquid outlet for overflowing perovskite coating liquid, a vacuum pipeline is arranged in the left die head, a negative pressure cavity is arranged at the die lip parts, and an inner sealing cavity is also arranged in the negative pressure cavity; and a first cavity, a second cavity, a liquid inlet channel and a liquid return channel which are convenient for the perovskite coating liquid to enter and exit are respectively arranged in the right die head. The invention also discloses a coating machine using the slit type coating die head. The invention realizes the stability and high-efficiency coating of the perovskite solution coating and improves the coating quality.

Description

Slit type coating die head for perovskite solution and coating machine thereof

Technical Field

The invention relates to a slit type coating die head for perovskite solution and a coating machine thereof.

Background

The precise coating of the perovskite solution is an important direction for the industrial production of the perovskite solar thin film cell. Slit coating is the most productive of these precision coating equipments, the best adjustment of coating window, and the product quality can be stable and controllable. Slit coating has a wide range of applications.

The perovskite solution has the characteristics of low viscosity, high density and high solid content. In a coating mode where the die is mounted vertically downward, the solution in the die cavity is susceptible to gravity flow out of the die slot. The perovskite solution also has the characteristic of fast crystal precipitation, and the crystal precipitation of the perovskite solution on the inner concave surface and the die lip part of the die head can be accelerated due to solvent evaporation, impurity induction and the like. The perovskite solution also has the characteristic of sensitivity to water and oxygen of the environment, and the perovskite solution can form by-products to accelerate the degradation of effective substances of the solution so as to make the solution ineffective when being contacted with the water and oxygen of the atmospheric environment. In a general slot coating process, the coating process is often unstable due to the properties of the perovskite solution, and the production quality and the process stability of products are seriously affected. Therefore, the slit coating apparatus for the perovskite solution needs to be specially designed.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a slit type coating die head and a coating machine thereof specially used for perovskite solution, so as to realize the stability and high-efficiency coating of perovskite solution coating and improve the coating quality.

The slit type coating die head for the perovskite solution comprises a left die head and a right die head which are fixed together through bolts, wherein the bottoms of the left die head and the right die head are provided with protruding die lip parts, the middle part of the die lip parts is provided with a liquid outlet for overflowing perovskite coating liquid, a vacuum pipeline is arranged in the left die head, a negative pressure cavity is arranged at the die lip parts, and an inner sealing cavity is also arranged in the negative pressure cavity; and a first cavity, a second cavity, a liquid inlet channel and a liquid return channel which are convenient for the perovskite coating liquid to enter and exit are respectively arranged in the right die head.

Furthermore, a negative pressure cavity suction opening is arranged at the position, close to the liquid outlet, of the negative pressure cavity, the negative pressure cavity suction opening is arranged in the direction parallel to the liquid outlet, the lower end of the vacuum pipeline is communicated with the negative pressure cavity, and the lower end of the inner sealing cavity is located between the liquid outlet and the negative pressure cavity suction opening.

Furthermore, the lower ports of the liquid inlet channel and the liquid return channel are respectively communicated with the first cavity, the height of the lower port of the liquid inlet channel is lower than that of the lower port of the liquid return channel, the lower port of the liquid return channel is located at the highest position of the first cavity, and direct current slits are respectively arranged between the first cavity and the second cavity and between the second cavity and the liquid outlet.

Further, the side wall of the negative pressure cavity is arc-shaped.

Furthermore, an exhaust port is arranged at the lower end of the inner sealing cavity, and the inner sealing cavity is filled with inert gas.

Further, an exhaust port is arranged at the lower end of the inner sealing cavity, a communication port is arranged on the side portion of the inner sealing cavity, and the exhaust port is communicated with the negative pressure cavity through the communication port.

Furthermore, liquid limiting grooves for preventing the perovskite coating liquid from overflowing outwards are respectively arranged at two ends of the liquid outlet and are grooves for blocking the liquid outlet.

Further, a third cavity is arranged in the right die head and is positioned between the first cavity and the second cavity, and direct current slits are respectively arranged between the first cavity and the third cavity and between the third cavity and the second cavity.

Further, a fourth cavity is arranged in the right die head and is positioned between the second cavity and the third cavity, and direct current slits are respectively arranged between the third cavity and the fourth cavity and between the fourth cavity and the second cavity.

The present invention has been achieved in this way, and provides a coater using the slit coating die for perovskite solution as described above.

Compared with the prior art, the slit type coating die head for the perovskite solution and the coating machine thereof have the following characteristics:

1. the die head which is in line with the slit type coating of the perovskite coating solution is designed completely according to the characteristics of the perovskite coating solution, and the stability and the efficiency of the coating are improved.

2. The die head adopts a multi-cavity design, a gasket and die head integrated design, a left die head and a right die head multi-screw fixing mode, a precise electromagnetic control liquid supply system and the like to ensure that the areas except the fluid pipeline in the die head are completely sealed. The design of the multi-cavity reduces the impact of high-flow solution of the liquid outlet on the solution distribution at the die lip, ensures the stability of the solution distribution, effectively shortens the length of a direct-flow area in the die head, and can reduce the hydraulic pressure of the solution under the condition of ensuring the solution distribution at the die lip to be uniform, thereby reducing the leakage and outflow of the perovskite coating solution with low viscosity and high density characteristics at the die lip due to the gravity, liquid supply hydraulic pressure and the like.

3. The nozzle of the die (die tip angle) is designed to be elongated (narrow and pointed in shape) so that the volume of solution dispensed between the die lip and the coated substrate during the coating operation is controlled to be small. Effectively reduces the volume of the solution directly exposed to the external environment and reduces the influence of the environment on the solution.

4. The design of the vacuum cavity and the inner sealing cavity also effectively reduces the volume of the solution exposed to the external environment at the die lip, and has good effect of improving the solution distribution stability of the sharp-long die head.

Drawings

FIG. 1 is a schematic perspective view of a slit coating die for perovskite solution according to a preferred embodiment of the present invention;

FIG. 2 is a perspective view of FIG. 1 from another angle;

FIG. 3 is a schematic cross-sectional view of M-M in FIG. 1;

FIG. 4 is a schematic perspective view of the right die of FIG. 1;

fig. 5 is a schematic view showing the thickness distribution of a perovskite wet film after coating using a slit coating die of a perovskite solution of the present invention.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

Referring to fig. 1, 2 and 3, a preferred embodiment of a slot coating die for perovskite solution according to the present invention includes a left die 1 and a right die 2 fixed together by bolts. Protruding die lips 3 are provided at the bottom of the left die 1 and the right die 2. A liquid outlet 4 for overflowing the perovskite coating liquid is arranged in the middle of the die lip part 3. The width of the liquid outlet 4 is the width of the slit of the coating die, and the length thereof is the coating range of the slit.

The width of the die lip 3 is 0.5mm to 1.5mm. The narrow die lip 3 facilitates a reduction in the amount of volume of perovskite coating solution dispensed onto the die lip, facilitates highly precise solution dispensing control of the die, and reduces the amount of exposed volume of perovskite coating solution in the atmosphere.

Referring to fig. 3 and 4, a first cavity 5, a second cavity 6, a third cavity 7, a liquid inlet channel 8 and a liquid return channel 9 are respectively disposed in the right die head 2 for the perovskite coating liquid to enter and exit. The lower ports of the liquid inlet channel 8 and the liquid return channel 9 are respectively communicated with the first cavity 5, the height of the lower port of the liquid inlet channel 8 is lower than that of the lower port of the liquid return channel 9, and the lower port of the liquid return channel 9 is located at the highest position of the first cavity 5. Such a positional design ensures that the perovskite coating solution can completely fill the inside of the cavity of the right die 2 under natural flow of gravity.

The third cavity 7 is located between the first cavity 5 and the second cavity 6, and a direct current slit 10 is respectively arranged between the first cavity 5 and the third cavity 7, between the third cavity 7 and the second cavity 6, and between the second cavity 6 and the liquid outlet 4. The purpose of the three cavities is to reduce the hydraulic pressure of the die lip solution and to ensure the uniformity and stability of the solution distribution of the perovskite coating solution within the right die 2.

The first cavity 5 has the functions of buffering and storing high-flow-rate perovskite coating solution of the liquid inlet channel 8, the lower side part of the first cavity 5 is designed into a special curved surface structure, acting force generated by fluid inflow is further released, and the perovskite coating solution is uniformly dispersed and flows out of the third cavity 7 and the second cavity 6 which are positioned at the lower part of the first cavity. The straight slit 10 is used for extrusion of the perovskite coating solution in the cavity of the right die head 2. The distribution state of the solution in the straight-through slot 10 including the pressure and the flow rate largely affects or determines the coating quality of the coating die.

The proper width setting of the many die cavities design and direct current slit 10 of this patent has ensured outside the evenly distributed of perovskite coating solution in 2 die cavities of right side die head, thereby has reduced the hydraulic pressure of die lip portion perovskite coating solution and has ensured that the perovskite coating solution in the coating die head is difficult for the gravity of solution and hydraulic influence when solution distributes and lead to the easy weeping of die lip portion. Leakage can result in the entry of ambient air into the interior of the mold cavity through the mold lip, affecting the stability of the dispensing of the perovskite coating solution and causing the perovskite coating solution to be disturbed by atmospheric water oxygen.

Referring to fig. 1, 2 and 3, a vacuum pipe 11 is disposed in the left die 1. A negative pressure cavity 12 is arranged at the die lip part 3, and a negative pressure cavity air suction opening 13 is arranged at the position of the negative pressure cavity 12 close to the liquid outlet 4. The suction port 13 of the negative pressure chamber is arranged in a direction parallel to the liquid outlet 4. The lower port of the vacuum pipeline 11 is communicated with the negative pressure cavity 12. An inner sealed cavity 14 is arranged in the negative pressure cavity 12, and the lower end of the inner sealed cavity 14 is positioned between the liquid outlet 4 and the negative pressure cavity suction opening 13.

The negative pressure cavity 12 is arranged to enable negative pressure to exist in the area close to one side of the die lip 3, so that the interference of air flow is favorably reduced in the rapid coating process of the coating die head, and the distribution stability of the perovskite coating solution is enhanced.

The side wall of the negative pressure cavity 12 is arc-shaped. The side wall of the negative pressure chamber 12 is composed of two menisci, and the curved surface design is beneficial to reducing turbulence and increasing the internal storage volume of the negative pressure chamber 12. The length of the suction port 13 of the negative pressure chamber 12 is identical to the coating width of the die. The width of the suction opening 13 of the negative pressure cavity can be adjusted by the tightening screw on the negative pressure cavity 12 to change the area of the suction opening of the negative pressure cavity 12, thereby adjusting the size of the treatment area of the negative pressure cavity 12 and the air pressure. The negative pressure chamber suction opening 13 faces the liquid outlet 4.

The lower end of the inner sealed cavity 14 is provided with the exhaust port 16, and the inner sealed cavity 14 is filled with inert gas, such as nitrogen or helium, so that the perovskite coating solution at the die part 3 can be ensured to be isolated from the external atmosphere, and the influence of external water and oxygen on the perovskite coating solution can be reduced.

As a new embodiment, an exhaust port 16 is provided at the lower end of the inner sealed chamber 14, and a communication port (not shown) is provided at the side portion of the inner sealed chamber 14, the communication port communicating the exhaust port 16 with the negative pressure chamber 12. The exhaust port 16 faces the liquid outlet 4.

Liquid limiting tanks 15 for preventing the perovskite coating liquid from overflowing to the outside are respectively arranged at two ends of the liquid outlet 4. The liquid limiting groove 15 is a groove for blocking the liquid outlet 4. The liquid restraining tank 15 is for preventing the perovskite coating solution of the die lip portion from flowing downstream to the entire both side non-coating regions of the die lip portion during the coating process, thereby causing instability in the distribution of the perovskite coating solution at the die lip portion to affect the coating film quality.

As a new embodiment, a fourth cavity is further disposed in the right die head 2, the fourth cavity is located between the second cavity 6 and the third cavity 7, and a direct current slit 10 is respectively disposed between the third cavity 7 and the fourth cavity and between the fourth cavity and the second cavity 6.

To protect the die from attack by the perovskite coating solution and to slow crystallization out of the perovskite coating solution. And preparing a high-density and high-hardness inert protective layer such as chromium nitride, silicon carbide and the like on the pipe of the die head, the surface of the cavity and the outer surface of the die lip by electroplating or vapor deposition and the like. The protective layer is not attacked by halogen ions in the perovskite coating solution and reduces adsorption of anions or cations, thereby reducing impurity induced deposition of perovskite into the cavity or die lip of the coating die.

The wet film thickness distribution of the perovskite after coating using the slit coating die of the perovskite solution of the present example is shown in fig. 5. In the linear direction of the die lip, the thickness distribution of the perovskite wet film is uniform and consistent, the film thickness uniformity can be controlled within 1 percent, the coating stability is good, and the coating quality is improved.

The invention also discloses a coater using the slit coating die for perovskite solution as described above.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A slit type coating die head for perovskite solution comprises a left die head and a right die head which are fixed together through bolts, and is characterized in that the bottoms of the left die head and the right die head are provided with protruded die lip parts, the middle part of the die lip parts is provided with a liquid outlet for overflowing perovskite coating liquid, a vacuum pipeline is arranged in the left die head, a negative pressure cavity is arranged at the die lip parts, and an inner sealing cavity is also arranged in the negative pressure cavity; and a first cavity, a second cavity, a liquid inlet channel and a liquid return channel which are convenient for the perovskite coating liquid to enter and exit are respectively arranged in the right die head.

2. The slot coating die head for perovskite solution as claimed in claim 1, wherein a negative pressure cavity suction port is provided at a position of the negative pressure cavity close to the liquid outlet, the negative pressure cavity suction port is provided in a direction parallel to the liquid outlet, a lower port of the vacuum pipe communicates with the negative pressure cavity, and a lower end of the inner sealed cavity is located between the liquid outlet and the negative pressure cavity suction port.

3. The slot coating die head for perovskite solution as claimed in claim 1, wherein the lower ports of the liquid inlet channel and the liquid return channel are respectively communicated with the first die cavity, the height of the lower port of the liquid inlet channel is lower than that of the lower port of the liquid return channel, the lower port of the liquid return channel is positioned at the highest position of the first die cavity, and the direct current slots are respectively arranged between the first die cavity and the second die cavity and between the second die cavity and the liquid outlet.

4. The slot coating die for a perovskite solution according to claim 1, wherein a side wall of the negative pressure chamber is curved.

5. The slot coating die for a perovskite solution according to claim 1, wherein a vent is provided at a lower end of the inner enclosure, and the inner enclosure is filled with an inert gas.

6. The slot coating die for a perovskite solution as claimed in claim 1, wherein a vent port is provided at a lower end of the inner closed cavity, and a communication port is provided at a side portion of the inner closed cavity, the communication port communicating the vent port with the negative pressure cavity.

7. The slot coating die for a perovskite solution according to claim 1, wherein liquid limiting grooves for preventing the perovskite coating liquid from overflowing to the outside are provided at both ends of the liquid outlet, respectively, and the liquid limiting grooves are grooves for blocking the liquid outlet.

8. The slot coating die head for perovskite solution as claimed in claim 1, wherein a third cavity is further provided in the right die head, the third cavity is located between the first cavity and the second cavity, and a direct current slot is provided between the first cavity and the third cavity and between the third cavity and the second cavity, respectively.

9. The slot coating die for perovskite solution according to claim 1, wherein a fourth cavity is further provided in the right die, the fourth cavity is positioned between the second cavity and the third cavity, and a direct current slot is provided between the third cavity and the fourth cavity and between the fourth cavity and the second cavity, respectively.

10. A coater using the slot coating die for perovskite solution according to any one of claims 1 to 9.