Drying system of coating solution including Anti-solvent and perovskite thin film forming apparatus including same

Abstract

The present invention relates to a drying system of a coating solution including an anti-solvent, the system being characterized by comprising: a drying unit for drying a coating solution while moving on an upper portion of the coating solution; a saturated water vapor pressure control unit for controlling the saturated water vapor pressure inside the drying unit; and a transfer unit for horizontally moving the drying unit above the coating solution, wherein the drying unit comprises: a drying housing of which at least a part of a lower surface is open; a gas discharge nozzle for discharging gas toward the coating solution from the inside of the drying housing; and a gas suction nozzle for suctioning the gas discharged from the gas discharge nozzle and in contact with the coating solution from the inside of the drying housing, wherein the gas discharge nozzle and the gas suction nozzle are installed to be inclined in opposite directions to each other so that the gas discharged from the gas discharge nozzle forms a local vortex above the coating solution to induce evaporation of the anti-solvent, and the saturated water vapor pressure control unit can control the saturated water vapor pressure of the gas inside the drying housing in contact with the coating solution to control the drying speed of the coating solution.

Description

Drying system for a coating solution containing an antisolvent and a perovskite thin film forming apparatus including the same

[0001] The present invention relates to a drying system for a coating solution containing an antisolvent and a perovskite thin film forming apparatus including the same, and more specifically, to an apparatus capable of uniformly drying a coating solution treated with an antisolvent for forming a perovskite thin film and a perovskite thin film forming apparatus including the same.

[0002] Generally, perovskites (ABX3) are octahedral materials in which A and B are cations and X is an anion; when X is composed of a halogen element, they are referred to as halide perovskites. Perovskites are being studied in various fields due to their excellent optical properties. They are attracting attention as next-generation light emitters because they not only possess higher color purity than conventional light-emitting layer materials in display devices but also allow for easy modification of optical properties and manufacturing. Furthermore, research on technologies for applying them as light-absorbing layers in solar cells is also actively underway.

[0003] Perovskite solar cells, which utilize perovskite crystals as a light-absorbing layer, absorb light across a broad wavelength range including the visible spectrum, and exhibit very high electron and hole mobility. Furthermore, they are gaining attention as a material for high-efficiency thin-film solar cells due to their high photon-to-electron conversion efficiency (EQE).

[0004] However, if the crystal size is not formed uniformly during the process of forming the perovskite thin film, a problem arises in which the efficiency of the device deteriorates rapidly.

[0005] Conventional perovskite light-absorbing layers utilized sequential processes or solvent engineering processes. The solvent engineering process controls the crystal formation of perovskite by using centrifugal force during the spin coating of a perovskite precursor solution to disperse an anti-solvent that selectively dissolves only the solvent without dissolving the perovskite.

[0006] The anti-solvent treatment method allows for the rapid removal of solvents that hinder perovskite crystallization from a precursor solution uniformly coated on a substrate, and the antisolvent is removed by vaporizing it through a heat treatment process following spin coating. This process is known to be the method capable of producing the most uniform crystals among currently known perovskite crystal formation methods.

[0007] However, due to the characteristics of the spin coating process, the area of ​​the formed thin film is limited, and there is a problem of increased crystal instability during the heat treatment process.

[0008] Although a technology has been developed to uniformly form perovskite crystals by controlling the evaporation of the antisolvent without applying a heat treatment process, a new method for applying the perovskite precursor solution and an apparatus for drying the antisolvent are currently required to evenly evaporate the antisolvent for large-area perovskite thin films.

[0009] The present invention aims to solve the problems of the aforementioned prior art by providing a drying system capable of forming a perovskite thin film having uniform crystals by uniformly drying a coating solution treated with an antisolvent for forming a perovskite thin film, and a perovskite thin film forming apparatus including the same.

[0010] A drying system for a coating liquid containing an antisolvent according to the present invention for achieving the above objective comprises: a drying unit that moves over the upper portion of the coating liquid and dries the coating liquid; a saturated vapor pressure control unit for controlling the saturated vapor pressure inside the drying unit; and a conveying unit for moving the drying unit horizontally over the upper portion of the coating liquid, wherein the drying unit comprises: a drying housing with at least a portion of its lower surface open; a gas discharge nozzle that discharges gas toward the coating liquid inside the drying housing; and a gas suction nozzle that sucks in the gas discharged from the gas discharge nozzle and in contact with the coating liquid inside the drying housing, wherein the gas discharge nozzle and the gas suction nozzle are installed at an angle in opposite directions so that the gas discharged from the gas discharge nozzle forms a local vortex over the upper portion of the coating liquid to induce evaporation of the antisolvent, and the saturated vapor pressure control unit controls the saturated vapor pressure of the gas inside the drying housing that contacts the coating liquid, thereby controlling the drying speed of the coating liquid.

[0011] The above-mentioned saturated water vapor pressure control unit may include a gas generator that generates a mixed gas in which two or more types of gases are mixed to control the saturated water vapor pressure, and an injection nozzle for injecting the mixed gas generated from the gas generator into the drying housing, and may control the saturated water vapor pressure of the gas inside the drying housing by adjusting the ratio of the mixed gas.

[0012] The above transfer unit is preferably capable of adjusting the gap between the drying housing and the coating liquid, and may include a sensor for measuring the gap between the drying housing and the coating liquid.

[0013] The above gas discharge nozzle may discharge gas in an inkjet manner.

[0014] It may further include a control unit for controlling the gas pressure discharged from the gas discharge nozzle and the gas pressure sucked in from the gas suction nozzle.

[0015] It is preferable that the open area on the lower surface of the drying housing can be adjusted, and a mask installed in the drying housing to adjust the open area on the lower surface of the drying housing may be further included.

[0016] A sensor for measuring the saturated water vapor pressure inside the above drying housing may be installed.

[0017] It may further include a solvent trap that separates the solvent from the gas sucked in from the above gas suction nozzle.

[0018] The above gas suction nozzle is a slit nozzle and may be an asymmetric nozzle configured such that the lengths of the nozzle ends positioned on both sides of the slit are different from each other.

[0019] A perovskite thin film forming apparatus according to another embodiment of the present invention comprises: a precursor solution dispensing nozzle for dispensing a perovskite precursor solution in an inkjet printing manner to form a primary precursor solution layer; a semi-solvent dispensing nozzle for dispensing a semi-solvent into the primary precursor solution layer to form a secondary precursor solution layer; and a drying system for drying the secondary precursor solution layer, wherein the drying system comprises: a drying unit that moves over the upper portion of the secondary precursor solution layer and dries the secondary precursor solution layer; a saturated water vapor pressure control unit for controlling the saturated water vapor pressure inside the drying unit; and a transfer unit for horizontally moving the drying unit over the upper portion of the secondary precursor solution layer, wherein the drying unit comprises: a drying housing having at least a portion of its lower surface open; and a gas discharge nozzle that discharges gas toward the secondary precursor solution layer inside the drying housing. The drying housing includes a gas suction nozzle that sucks in gas discharged from the gas discharge nozzle and in contact with a secondary precursor solution layer inside the drying housing, wherein the gas discharge nozzle and the gas suction nozzle are installed at an angle in opposite directions so that the gas discharged from the gas discharge nozzle forms a local vortex on the upper part of the secondary precursor solution layer to induce evaporation of the antisolvent, and the saturated water vapor pressure control unit controls the saturated water vapor pressure of the gas inside the drying housing in contact with the secondary precursor solution layer, thereby controlling the drying speed of the secondary precursor solution layer.

[0020] The above anti-solvent discharge nozzle may discharge the anti-solvent using an inkjet printing method.

[0021] The present invention, configured as described above, has the effect of rapidly removing the anti-solvent by utilizing a vortex formed by performing gas discharge and suction on a local portion of a coating liquid containing an anti-solvent.

[0022] In addition, by controlling the saturated water vapor pressure around the area where gas discharge and suction are performed, the drying speed of the coating solution can be controlled, thereby providing an excellent effect of controlling the time required for the crystallization of perovskite.

[0023] FIG. 1 is a schematic diagram illustrating the configuration of a drying system for a coating solution containing an antisolvent according to an embodiment of the present invention.

[0024] FIG. 2 is a schematic diagram illustrating the drying section of a drying system for a coating liquid containing an antisolvent according to the first embodiment of the present invention.

[0025] FIG. 3 is a schematic diagram illustrating the drying section of a drying system for a coating liquid containing an antisolvent according to a second embodiment of the present invention.

[0026] FIG. 4 is a schematic diagram illustrating the configuration of a perovskite thin film forming apparatus according to a third embodiment of the present invention.

[0027] FIG. 5 is a schematic diagram illustrating the configuration of a perovskite thin film forming apparatus according to the fourth embodiment of the present invention.

[0028] An embodiment according to the present invention will be described in detail with reference to the attached drawings.

[0029] However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited only to the embodiments described below. The shapes and sizes of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

[0030] Furthermore, throughout the specification, when a part is described as being "connected" to another part, this includes not only cases where they are "directly connected" but also cases where they are "electrically connected" with other components interposed between them. Additionally, when a part is described as "including" or "equipped" with a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but rather allows for the inclusion or equipping of additional components.

[0031] Furthermore, terms such as "first," "second," etc., are intended to distinguish one component from another, and the scope of rights shall not be limited by these terms. For example, the first component may be named the second component, and similarly, the second component may be named the first component.

[0032]

[0033] FIG. 1 is a schematic diagram illustrating the configuration of a drying system for a coating solution containing an antisolvent according to an embodiment of the present invention.

[0034] A drying system for a coating liquid containing an antisolvent according to an embodiment of the present invention includes a drying unit (100), a saturated water vapor pressure control unit (200), and a transfer unit (300).

[0035] The present invention relates to a drying system used in an anti-solvent treatment method that controls crystal formation by using an anti-solvent that selectively dissolves only the solvent in a solution process for forming a thin film or pattern composed of a specific material, wherein the material or precursor material is dissolved in a solvent. In particular, the present invention was derived during the process of researching a technology for drying a secondary precursor solution layer to which an anti-solvent is added to a primary precursor solution layer for forming a uniform crystalline thin film during the process of forming a perovskite thin film. The following description is based on the configuration for forming a perovskite thin film, but is not limited thereto.

[0036] The drying unit (100) is a component that forms a thin film by drying the coating solution while moving the upper part of the coating solution in a horizontal direction. The coating solution is a solution in which a thin film constituent material or a precursor material thereof to be formed is dissolved, and a thin film is formed by evaporating the solvent, and at this time, it is preferable that the solution has an added anti-solvent that selectively dissolves only the solvent.

[0037] In the antisolvent treatment method, both the solvent of the precursor solution and the added antisolvent must be removed. Furthermore, to form a thin film containing uniform crystals, the overall drying speed must be controlled along with the rapid evaporation of the antisolvent. When forming a perovskite thin film over a relatively small area using spin coating, it may be possible to uniformly evaporate the secondary precursor solution layer containing the added antisolvent without the application of special equipment. However, since perovskite thin films produced by spin coating have a small area and the coating process is time-consuming, it is difficult to apply this method to the rapid production of large-area thin films, such as the light-absorbing layer of solar cells.

[0038] Accordingly, the present invention provides a drying system of a novel structure capable of drying by appropriately controlling the evaporation of the antisolvent and the solvent while moving horizontally above a secondary precursor solution layer containing an antisolvent.

[0039] A drying unit (100) applied to a drying system for a coating liquid containing an antisolvent according to an embodiment of the present invention includes a drying housing (110), a gas discharge nozzle (120), and a gas suction nozzle (130).

[0040] The drying housing (110) is a component for providing a region that controls the evaporation environment of the solvent above a secondary precursor solution layer to which an antisolvent has been added. Specifically, the present invention controls the evaporation environment of the solvent contained in the coating solution by controlling the saturated water vapor pressure in the internal space of the drying housing (110). To this end, the drying housing (110) has a structure in which at least a portion of the lower surface is open, and the internal gas, in which the saturated water vapor pressure is controlled, comes into contact with the surface of the coating solution through the open portion of the lower surface, thereby controlling the evaporation of the solvent contained in the coating solution.

[0041] The gas discharge nozzle (120) and the gas suction nozzle (130) are configured to form a local vortex on the upper surface of the coating liquid to induce the evaporation of the antisolvent. To this end, the gas discharge nozzle (120) and the gas suction nozzle (130) are installed at an angle opposite to each other, and the structure is such that gas discharged from the gas discharge nozzle (120) toward the coating liquid is sucked in by the gas suction nozzle (130). At this time, the force resulting from the movement of the gas discharged at an angle from the gas discharge nozzle (120) and the force resulting from the movement of the gas sucked in at an angle from the gas suction nozzle (130) are combined to form a local vortex on the upper surface of the coating liquid, and the evaporation of the antisolvent is promoted by this vortex, thereby enabling the formation of a uniformly crystalline perovskite thin film.

[0042] The gas discharge nozzle (120) and the gas intake nozzle (130) may have a structure in which circular nozzles are arranged in a line, or a structure in which linear slit nozzles, represented as air knives, are formed.

[0043] At this time, when configuring the gas suction nozzle (130) as a slit nozzle, an asymmetric nozzle may be applied in which the lengths of the nozzle ends positioned on both sides relative to the slit are configured differently. In a slit nozzle installed in an inclined shape, by configuring the nozzle end on the side located on the upper side relatively short and the nozzle end on the side located on the lower side relatively long, the suction effect of the gas that gradually spreads out as it is emitted from the gas discharge nozzle (120) and reflected from the surface of the coating liquid can be enhanced, and accordingly, the effect of facilitating the formation of a vortex can be obtained.

[0044] Meanwhile, in order to form and control the vortex, it is necessary to precisely control the gas pressure discharged from the gas discharge nozzle (120) and the gas pressure sucked in from the gas suction nozzle (130), and may further include a control unit (not shown) for controlling the gas pressure discharged from the gas discharge nozzle (120) and the gas pressure sucked in from the gas suction nozzle (130).

[0045] Furthermore, when the gas discharge nozzle (120) discharges gas in an inkjet manner, more precise gas flow rate control is possible.

[0046] The gas sucked in by the gas suction nozzle (130) contains evaporated solvent and anti-solvent, and by adding a solvent trap (not shown) capable of capturing them, the solvent or anti-solvent can be recycled or environmental pollution caused by the solvent or anti-solvent can be prevented.

[0047] The saturated water vapor pressure control unit (200) is a component for controlling the saturated water vapor pressure in the internal space of the drying housing (110).

[0048] As explained above, the saturated water vapor pressure of the gas filled inside the drying housing (110) must be controlled, and furthermore, since the gas inside is continuously leaking out through the open part on the bottom of the drying housing (110), it is necessary to maintain the controlled saturated water vapor pressure inside the drying housing (110).

[0049] In this embodiment, as a method for controlling saturated water vapor pressure, a mixed gas comprising two or more types of gases capable of controlling saturated water vapor pressure is used, and for this purpose, a gas generator (210) may be included. For example, two or more solutions such as DMSO and DMF used in the perovskite process are mixed in a certain ratio and then vaporized, or a mixed gas is generated by mixing after vaporization and then supplying this to the inside of the drying housing (110) to control the saturated water vapor pressure, and the drying speed and crystallization can be controlled using this.

[0050] Additionally, it includes an injection nozzle (220) for injecting the mixed gas generated from the gas generator (210) into the interior of the drying housing (110) and for continuously filling the mixed gas flowing out through the bottom surface of the drying housing (110) to maintain a controlled saturated water vapor pressure.

[0051] Meanwhile, by installing a sensor (not shown) that measures the saturated water vapor pressure inside the drying housing (110), the saturated water vapor pressure control unit (200) can appropriately control the saturated water vapor pressure inside the drying housing (110).

[0052] The transfer unit (300) is a component for moving the drying unit (100) to perform drying while moving over a large area of ​​the coating liquid surface.

[0053] First of all, since the drying unit (100) must dry the coating liquid while moving horizontally from the top of the coating liquid and moving through the open space on the bottom of the drying housing (110) and the location of the local vortex formed by the gas discharge nozzle (120) and the gas suction nozzle (130), the conveying unit (300) requires a horizontal conveyor (310).

[0054] In addition, the horizontal conveyor (310) can control the crystallization time by adjusting the distance from the nozzle applying the antisolvent, thereby controlling the time from the application of the antisolvent to the drying process.

[0055] In addition, since it is necessary to adjust the gap between the drying housing (110) and the coating liquid, a vertical conveyor (320) that moves the drying housing (110) in a vertical direction is additionally provided.

[0056] And a sensor (not shown) is installed to measure the gap between the drying housing (110) and the coating liquid.

[0057]

[0058] In this way, the drying system of the present invention can form a perovskite thin film with uniformly grown crystals by rapidly and uniformly drying a secondary precursor solution layer in which an antisolvent is added to a precursor solution through the control of the drying environment by controlling the saturated water vapor pressure inside the drying housing and the control of the evaporation of the antisolvent by local vortices formed by the gas discharge nozzle and the gas suction nozzle.

[0059] The specific structure of the components applied to the drying system is described below.

[0060]

[0061] FIG. 2 is a schematic diagram illustrating the drying section of a drying system for a coating liquid containing an antisolvent according to the first embodiment of the present invention.

[0062] The illustrated embodiment describes a case where the drying housing (110) dries the coating liquid while moving to the right along the direction of the arrow.

[0063] The coating solution is a secondary precursor solution layer (10) in which an antisolvent is added to the precursor solution layer, and a perovskite thin film (20) is formed by evaporating the solvent and the antisolvent as the drying housing (110) passes through the secondary precursor solution layer (10).

[0064] The interior of the drying housing (110), with a portion of the lower surface open, is filled with mixed gas injected by the injection nozzle (220).

[0065] At this time, since the mixed gas comes into contact with the coating liquid through the open bottom of the drying housing (110) and the mixed gas is continuously discharged, the mixed gas must be continuously injected through the injection nozzle (220). Since the mixed gas must be injected evenly throughout the interior of the drying housing (110), it is preferable that the injection nozzle (220) be installed on each side.

[0066] A gas discharge nozzle (120) and a gas suction nozzle (130) are installed at an angle to each other, and a local vortex is formed on the upper surface of the coating liquid by a structure in which gas discharged from the gas discharge nozzle (120) toward the coating liquid is sucked in by the gas suction nozzle (130). The vortex formed in this way rapidly evaporates the anti-solvent. Since the vaporization of the anti-solvent is promoted only in the narrow area where the local vortex is generated, not only can the anti-solvent be rapidly evaporated, but it also has the effect of providing almost identical drying conditions over the entire area to which the drying housing (110) has moved.

[0067] As described above, in this embodiment, the gas suction nozzle (130) is configured as a slit nozzle, and an asymmetric nozzle is applied in which the nozzle end on the side located above the slit is configured to be relatively short and the nozzle end on the side located below the slit is configured to be relatively long. In this structure, even when the gas discharged from the gas discharge nozzle (120) gradually spreads out widely, the effect of increasing the gas suction effect and promoting the formation of a vortex is achieved by the nozzle end configured to be relatively long.

[0068] Meanwhile, the open portion on the lower surface of the drying housing (110) is the area where drying takes place, and the area of ​​the drying area can be controlled by adjusting the open area, thereby controlling the crystallization rate. Therefore, a configuration that can adjust the area of ​​the open portion on the lower surface of the drying housing (110) can be applied, and the drying housing (110) itself may include a configuration for adjusting the open area, or a configuration that adjusts the open area using a separate part may be applied.

[0069]

[0070] FIG. 3 is a schematic diagram illustrating the drying section of a drying system for a coating liquid containing an antisolvent according to a second embodiment of the present invention.

[0071] The illustrated embodiment describes a case where the drying housing (110) dries the coating liquid while moving to the right along the direction of the arrow.

[0072] The coating solution is a secondary precursor solution layer (10) in which an antisolvent is added to the precursor solution layer, and a perovskite thin film (20) is formed by evaporating the solvent and the antisolvent as the drying housing (110) passes through the secondary precursor solution layer (10).

[0073] The interior of the drying housing (110), with a portion of the lower surface open, is filled with mixed gas injected by the injection nozzle (220).

[0074] At this time, since the mixed gas comes into contact with the coating liquid through the open bottom of the drying housing (110) and the mixed gas is continuously discharged, the mixed gas must be continuously injected through the injection nozzle (220). Since the mixed gas must be injected evenly throughout the interior of the drying housing (110), it is preferable that the injection nozzle (220) be installed on each side.

[0075] A gas discharge nozzle (120) and a gas suction nozzle (130) are installed at an angle to each other, and a local vortex is formed on the upper surface of the coating liquid by a structure in which gas discharged from the gas discharge nozzle (120) toward the coating liquid is sucked in by the gas suction nozzle (130). The vortex formed in this way rapidly evaporates the anti-solvent. Since the vaporization of the anti-solvent is promoted only in the narrow area where the local vortex is generated, not only can the anti-solvent be rapidly evaporated, but it also has the effect of providing almost identical drying conditions over the entire area to which the drying housing (110) has moved.

[0076] As described above, in this embodiment, the gas suction nozzle (130) is configured as a slit nozzle, and an asymmetric nozzle is applied in which the nozzle end on the side located above the slit is configured to be relatively short and the nozzle end on the side located below the slit is configured to be relatively long. In this structure, even when the gas discharged from the gas discharge nozzle (120) gradually spreads out widely, the effect of increasing the gas suction effect and promoting the formation of a vortex is achieved by the nozzle end configured to be relatively long.

[0077] The illustrated embodiment is characterized by adding a mask (140) to the lower part of the drying housing (110) to adjust the area of ​​the open portion on the lower surface of the drying housing (110). The mask (140) is configured to be detachably attached to the lower part of the drying housing (110) and may be equipped with a plurality of masks having different areas of open portions, and may adjust the area of ​​the open portion on the lower surface of the drying housing (110) by attaching a mask (140) that has an open space formed with an appropriate area as needed. The open portion on the lower surface of the drying housing (110) is the area where drying takes place, and by adjusting the open area, the area of ​​the region where drying is performed can be adjusted, thereby allowing the crystallization rate to be controlled.

[0078]

[0079] A perovskite thin film forming apparatus according to another embodiment of the present invention includes a precursor solution discharge nozzle, an antisolvent discharge nozzle, and a drying system.

[0080] The precursor solution discharge nozzle is a component for discharging a precursor solution to form a primary precursor solution layer to form a perovskite.

[0081] The primary precursor solution layer must be formed with a uniform thickness to improve the quality of the perovskite thin film. This is related to quality improvement due to uniform thickness, as well as quality improvement due to uniform crystal formation.

[0082] Conventionally, spin coating was applied to form a uniform primary precursor solution layer, but it has the disadvantage of limiting the application area and the shape of the thin film.

[0083] In contrast, the present invention is characterized by dispensing a precursor solution through an inkjet printing method.

[0084] Generally, inkjet printing technology refers to a technology that sprays liquid ink in the form of droplets onto the surface of a medium according to a shape signal, and creates patterns or thin films directly on a printing target by spraying small droplets at a frequency of hundreds of times per second or more by force from electricity or magnetism or pneumatic pressure.

[0085] Although this inkjet printing technology originated in the publishing printing field as a printing method for creating documents or advertisements, its application in industrial fields is gradually increasing due to its ability to form droplet patterns with high precision. In particular, the scope of inkjet printing applications is expanding, such as being used in semiconductor or display fields to form complex patterns on substrates or in solution processes to accurately eject ink only at specific locations. Efforts are also continuing to apply inkjet printing technology as a method to form small, precise patterns in various electronic devices.

[0086] In this embodiment, an inkjet printing method is applied to form a primary precursor solution layer of uniform thickness. At this time, since general inkjet printing technology for coating the solution layer can be applied without limitation within a range that does not impair the features of the present invention, a detailed description is omitted.

[0087] Meanwhile, forming a uniform crystalline perovskite thin film in a large-area coating solution formed by an inkjet printing method can be problematic, but the present invention can rapidly form a high-quality perovskite thin film over a large area by applying the drying system described above.

[0088] An anti-solvent discharge nozzle is a component for forming a secondary precursor solution layer by adding an anti-solvent that selectively dissolves only the solvent to a primary precursor solution layer coated with a uniform thickness using an inkjet printing method.

[0089] The method of the anti-solvent discharge nozzle is not particularly limited, and a general slit nozzle or an inkjet printing method may be applied. In particular, when an inkjet printing method is applied, general inkjet printing technology for coating the solution layer can be applied without limitation within a range that does not impair the features of the present invention, so a detailed description is omitted.

[0090] The drying system is a component for drying the secondary precursor solution layer to induce the growth of uniform crystals while rapidly removing the antisolvent.

[0091] Since the drying system can be configured as shown in FIG. 1, a detailed description is omitted.

[0092]

[0093] FIG. 4 is a schematic diagram illustrating the configuration of a perovskite thin film forming apparatus according to a third embodiment of the present invention.

[0094] The illustrated embodiment describes a case in which a perovskite thin film is formed by moving to the right along the direction of the arrow.

[0095] First, a precursor solution discharge nozzle (400) discharges droplets of the precursor solution (40) to form a primary precursor solution layer (30).

[0096] The precursor solution discharge nozzle (400) can form a primary precursor solution layer (30) of uniform thickness by discharging droplets of the precursor solution (40) in an inkjet printing manner.

[0097] Next, the antisolvent discharge nozzle (500) discharges droplets of antisolvent (50) into the primary precursor solution layer (30) to form a secondary precursor solution layer (10).

[0098] The antisolvent discharge nozzle (500) adds droplets of antisolvent (50) to the primary precursor solution layer (30) by applying a slit nozzle or an inkjet printing method. By controlling the crystal formation of perovskite through an antisolvent treatment method that controls crystal formation using an antisolvent that selectively dissolves only the solvent, a perovskite thin film having uniform crystals can be formed.

[0099] Through the configuration described above, the drying system controls the drying environment by controlling the saturated water vapor pressure inside the drying housing and controls the evaporation of the antisolvent by local vortices formed by the gas discharge nozzle and the gas suction nozzle, and can finally form a high-quality perovskite thin film with uniformly grown crystals over a large area.

[0100] A perovskite thin film (20) is formed by evaporating the solvent and antisolvent as the drying housing (110) passes through the secondary precursor solution layer (10).

[0101] The interior of the drying housing (110), with a portion of the lower surface open, is filled with mixed gas injected by the injection nozzle (220).

[0102] At this time, since the mixed gas comes into contact with the coating liquid through the open bottom of the drying housing (110) and the mixed gas is continuously discharged, the mixed gas must be continuously injected through the injection nozzle (220). Since the mixed gas must be injected evenly throughout the interior of the drying housing (110), it is preferable that the injection nozzle (220) be installed on each side.

[0103] A gas discharge nozzle (120) and a gas suction nozzle (130) are installed at an angle to each other, and a local vortex is formed on the upper surface of the coating liquid by a structure in which gas discharged from the gas discharge nozzle (120) toward the coating liquid is sucked in by the gas suction nozzle (130). The vortex formed in this way rapidly evaporates the anti-solvent. Since the vaporization of the anti-solvent is promoted only in the narrow area where the local vortex is generated, not only can the anti-solvent be rapidly evaporated, but it also has the effect of providing almost identical drying conditions over the entire area to which the drying housing (110) has moved.

[0104] As described above, in this embodiment, the gas suction nozzle (130) is configured as a slit nozzle, and an asymmetric nozzle is applied in which the nozzle end on the side located above the slit is configured to be relatively short and the nozzle end on the side located below the slit is configured to be relatively long. In this structure, even when the gas discharged from the gas discharge nozzle (120) gradually spreads out widely, the effect of increasing the gas suction effect and promoting the formation of a vortex is achieved by the nozzle end configured to be relatively long.

[0105] Meanwhile, the open portion on the lower surface of the drying housing (110) is the area where drying takes place, and the area of ​​the drying area can be controlled by adjusting the open area, thereby controlling the crystallization rate. Therefore, a configuration that can adjust the area of ​​the open portion on the lower surface of the drying housing (110) can be applied, and the drying housing (110) itself may include a configuration for adjusting the open area, or a configuration that adjusts the open area using a separate part may be applied.

[0106]

[0107] FIG. 5 is a schematic diagram illustrating the configuration of a perovskite thin film forming apparatus according to the fourth embodiment of the present invention.

[0108] The illustrated embodiment describes a case in which a perovskite thin film is formed by moving to the right along the direction of the arrow.

[0109] First, a precursor solution discharge nozzle (400) discharges droplets of the precursor solution (40) to form a primary precursor solution layer (30).

[0110] The precursor solution discharge nozzle (400) can form a primary precursor solution layer (30) of uniform thickness by discharging droplets of the precursor solution (40) in an inkjet printing manner.

[0111] Next, the antisolvent discharge nozzle (500) discharges droplets of antisolvent (50) into the primary precursor solution layer (30) to form a secondary precursor solution layer (10).

[0112] The antisolvent discharge nozzle (500) adds droplets of antisolvent (50) to the primary precursor solution layer (30) by applying a slit nozzle or an inkjet printing method. By controlling the crystal formation of perovskite through an antisolvent treatment method that controls crystal formation using an antisolvent that selectively dissolves only the solvent, a perovskite thin film having uniform crystals can be formed.

[0113] Through the configuration described above, the drying system controls the drying environment by controlling the saturated water vapor pressure inside the drying housing and controls the evaporation of the antisolvent by local vortices formed by the gas discharge nozzle and the gas suction nozzle, and can finally form a high-quality perovskite thin film with uniformly grown crystals over a large area.

[0114] A perovskite thin film (20) is formed by evaporating the solvent and antisolvent as the drying housing (110) passes through the secondary precursor solution layer (10).

[0115] The interior of the drying housing (110), with a portion of the lower surface open, is filled with mixed gas injected by the injection nozzle (220).

[0116] At this time, since the mixed gas comes into contact with the coating liquid through the open bottom of the drying housing (110) and the mixed gas is continuously discharged, the mixed gas must be continuously injected through the injection nozzle (220). Since the mixed gas must be injected evenly throughout the interior of the drying housing (110), it is preferable that the injection nozzle (220) be installed on each side.

[0117] A gas discharge nozzle (120) and a gas suction nozzle (130) are installed at an angle to each other, and a local vortex is formed on the upper surface of the coating liquid by a structure in which gas discharged from the gas discharge nozzle (120) toward the coating liquid is sucked in by the gas suction nozzle (130). The vortex formed in this way rapidly evaporates the anti-solvent. Since the vaporization of the anti-solvent is promoted only in the narrow area where the local vortex is generated, not only can the anti-solvent be rapidly evaporated, but it also has the effect of providing almost identical drying conditions over the entire area to which the drying housing (110) has moved.

[0118] As described above, in this embodiment, the gas suction nozzle (130) is configured as a slit nozzle, and an asymmetric nozzle is applied in which the nozzle end on the side located above the slit is configured to be relatively short and the nozzle end on the side located below the slit is configured to be relatively long. In this structure, even when the gas discharged from the gas discharge nozzle (120) gradually spreads out widely, the effect of increasing the gas suction effect and promoting the formation of a vortex is achieved by the nozzle end configured to be relatively long.

[0119] The illustrated embodiment is characterized by adding a mask (140) to the lower part of the drying housing (110) to adjust the area of ​​the open portion on the lower surface of the drying housing (110). The mask (140) is configured to be detachably attached to the lower part of the drying housing (110) and may be equipped with a plurality of masks having different areas of open portions, and may adjust the area of ​​the open portion on the lower surface of the drying housing (110) by attaching a mask (140) that has an open space formed with an appropriate area as needed. The open portion on the lower surface of the drying housing (110) is the area where drying takes place, and by adjusting the open area, the area of ​​the region where drying is performed can be adjusted, thereby allowing the crystallization rate to be controlled.

[0120]

[0121] In this way, the perovskite thin film forming apparatus of the present invention can form a high-quality perovskite thin film with uniformly grown crystals over a large area by rapidly and uniformly drying a secondary precursor solution layer in which an antisolvent is added to the precursor solution through controlling the drying environment by controlling the saturated water vapor pressure inside the drying housing and controlling the evaporation of the antisolvent by local vortices formed by a gas discharge nozzle and a gas suction nozzle.

[0122]

[0123] The present invention has been described above through preferred embodiments. However, the aforementioned embodiments are merely illustrative of the technical concept of the present invention, and those skilled in the art will understand that various modifications are possible within the scope of the technical concept of the present invention. Therefore, the scope of protection of the present invention should be interpreted by the matters described in the claims rather than by specific embodiments, and all technical concepts within an equivalent scope should also be interpreted as being included within the scope of rights of the present invention.

Claims

1. A drying unit that moves over the upper part of the coating liquid and dries the coating liquid; A saturated water vapor pressure control unit for controlling the saturated water vapor pressure inside the above drying unit; and It includes a transfer unit for horizontally moving the above drying unit above the coating liquid, The above drying unit is, Dry housing with at least a portion of the lower surface open; A gas discharge nozzle that discharges gas toward the coating liquid inside the above drying housing; It includes a gas suction nozzle that sucks in gas emitted from the gas discharge nozzle and in contact with the coating liquid inside the above drying housing, The gas discharge nozzle and the gas suction nozzle are installed at an angle in opposite directions, so that the gas discharged from the gas discharge nozzle forms a local vortex at the top of the coating liquid to induce the evaporation of the antisolvent, and A drying system for a coating solution containing an antisolvent, characterized in that the above-described saturated water vapor pressure control unit controls the saturated water vapor pressure of the gas inside the drying housing in contact with the coating solution, thereby controlling the drying speed of the coating solution.

2. In Claim 1, The above-mentioned saturated water vapor pressure control unit is, It includes a gas generator that generates a mixed gas comprising two or more types of gases to control saturated water vapor pressure, and an injection nozzle for injecting the mixed gas generated from the gas generator into the interior of the drying housing. A drying system for a coating liquid containing an antisolvent, characterized by controlling the saturated water vapor pressure of the gas inside the drying housing by controlling the ratio of the mixed gas.

3. In Claim 1, A drying system for a coating liquid containing an antisolvent, characterized in that the above-described transfer unit can adjust the gap between the drying housing and the coating liquid.

4. In Claim 3, A drying system for a coating solution containing an antisolvent, characterized by including a sensor that measures the gap between the drying housing and the coating solution.

5. In Claim 1, A drying system for a coating liquid containing an antisolvent, characterized in that the above gas discharge nozzle discharges gas in an inkjet manner.

6. In Claim 1, A drying system for a coating liquid containing an antisolvent, characterized by further including a control unit for controlling the gas pressure discharged from the gas discharge nozzle and the gas pressure sucked in from the gas suction nozzle.

7. In Claim 1, A drying system for a coating liquid containing an anti-solvent, characterized by being able to adjust the open area on the lower surface of the drying housing.

8. In Claim 7, A drying system for a coating liquid containing an anti-solvent, characterized by further including a mask installed in the drying housing and controlling the open area of ​​the lower surface of the drying housing.

9. In Claim 1, A drying system for a coating liquid containing an antisolvent, characterized by having a sensor installed to measure the saturated water vapor pressure inside the drying housing.

10. In Claim 1, A drying system for a coating liquid containing an antisolvent, characterized by further including a solvent trap for separating the solvent from the gas sucked in from the above gas suction nozzle.

11. In Claim 1, A drying system for a coating liquid containing an anti-solvent, characterized in that the above gas suction nozzle is a slit nozzle and is an asymmetric nozzle in which the lengths of the nozzle ends positioned on both sides of the slit are configured to be different from each other.

12. A precursor solution dispensing nozzle that forms a primary precursor solution layer by dispensing a perovskite precursor solution using an inkjet printing method; A semisolvent discharge nozzle that discharges a semisolvent into a primary precursor solution layer to form a secondary precursor solution layer; and It includes a drying system for drying a secondary precursor solution layer, and The above drying system is, A drying unit that moves over the upper portion of the secondary precursor solution layer and dries the secondary precursor solution layer; A saturated water vapor pressure control unit for controlling the saturated water vapor pressure inside the above drying unit; and It includes a transfer unit for horizontally moving the above drying unit on the upper side of the secondary precursor solution layer, The above drying unit is, Dry housing with at least a portion of the lower surface open; A gas discharge nozzle that discharges gas toward a secondary precursor solution layer inside the above drying housing; It includes a gas suction nozzle that sucks in gas emitted from the gas discharge nozzle and in contact with the secondary precursor solution layer inside the drying housing, The gas discharge nozzle and the gas suction nozzle are installed at an angle in opposite directions, so that the gas discharged from the gas discharge nozzle forms a local vortex at the top of the secondary precursor solution layer to induce the evaporation of the antisolvent, and A perovskite thin film forming apparatus characterized in that the above-described saturated water vapor pressure controlling unit controls the saturated water vapor pressure of the gas inside the drying housing in contact with the secondary precursor solution layer, thereby controlling the drying speed of the secondary precursor solution layer.

13. In Claim 12, A perovskite thin film forming apparatus characterized by the above-mentioned antisolvent discharge nozzle discharging an antisolvent using an inkjet printing method.

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