JP5981594B1 - Coating method and coating apparatus - Google Patents

Abstract

An object of the present invention is to improve coating accuracy in a meniscus coating method. An application method includes a step of superimposing an application head and an application surface of an application object, supplying an application material between the application head and the application surface, and supplying an application material, A step of applying a coating material from one region to a second region; a step of replenishing the coating material after coating the coating material to the second region; and a step of replenishing the coating material, Applying a coating material from the region to the third region. [Selection] Figure 1

Description

  Embodiments described herein relate generally to a coating method and a coating apparatus.

  A photoelectric conversion element such as an organic thin film solar cell using an organic semiconductor is expected as a low-cost solar cell because an inexpensive coating method can be applied to the formation of the photoactive layer. The cell constituting the organic thin film solar cell has a structure in which, for example, a photoactive layer is sandwiched between a transparent electrode and a counter electrode.

  A meniscus coating method is known as one of methods for forming a film containing an organic material used for a photoactive layer or the like. In the meniscus coating method, a meniscus column is formed by supplying a coating material between a coating head and a coating surface of a coating object. Thereafter, the coating material is applied to the coating surface by relatively moving the coating head and the coating object.

  In the conventional meniscus coating method, it is difficult to control the thickness and width of the coating pattern. In particular, when a coating pattern having a length exceeding 100 mm is formed by, for example, a roll-to-roll method in order to increase the area or mass production of the photoelectric conversion element, the influence due to variations in the thickness and width of the coating pattern is remarkable. Thus, the above variation causes, for example, a decrease in photoelectric conversion efficiency.

JP 2013-066683 A

  The problem to be solved by the invention of the embodiment is to improve the coating accuracy in the meniscus coating method.

The application method of the embodiment includes a step of superimposing an application head and an application surface of an application object, supplying a first amount of application material between the application head and the application surface, and after supplying the application material, The step of applying the coating material from the first region to the second region of the coating surface by moving the coating head or the coating object along one direction of the coating surface, and coating the coating material to the second region After that, a second amount of coating material smaller than the first amount is replenished between the coating head and the coating surface while stopping the coating head or the coating object on the second region, or the coating material is A second amount is applied between the coating head and the coating surface while moving the coating head or the coating object along one direction of the coating surface at a speed slower than the moving speed of the coating head or the coating object in the coating step. a step of replenishing the coating material, After supplemented with 2 amount of coating material, a second amount of the coating head or the application target along the direction of the coated surface at a speed higher than the moving speed of the coating head or object to be coated in the step of replenishing the coating material And applying a coating material from the second area to the third area of the application surface by moving the object.

It is a schematic diagram which shows the structural example of a coating device. It is a schematic diagram which shows the structural example of a coating head. It is a cross-sectional schematic diagram which shows the structural example of an application | coating area | region. It is a cross-sectional schematic diagram which shows the structural example of an application | coating area | region. It is a schematic diagram for demonstrating an example of the coating method. It is a schematic diagram for demonstrating an example of the coating method. It is a schematic diagram for demonstrating an example of the coating method. It is a schematic diagram for demonstrating an example of the coating method. It is a schematic diagram for demonstrating the other example of the coating method. It is a schematic diagram for demonstrating the other example of the coating method. It is a schematic diagram which shows the other structural example of a moving mechanism. It is a schematic diagram which shows the structural example of a photoelectric conversion element. It is a schematic diagram which shows the structural example of a photoelectric conversion element. It is a schematic diagram which shows the structural example of a photoelectric conversion element. It is a schematic diagram which shows the structural example of a photoelectric conversion element.

  Hereinafter, embodiments will be described with reference to the drawings. The drawings are schematic, and for example, the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like may be different from the actual ones. In the embodiments, substantially the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

(First embodiment)
FIG. 1 is a schematic diagram illustrating a configuration example of a coating apparatus. The coating apparatus shown in FIG. 1 includes a coating head 1, a supply mechanism 2, a moving mechanism 3 that moves the coating head 1, a moving mechanism 4 that moves a coating object 10, and a control mechanism 5 that controls the moving mechanism 3. And a control mechanism 6 that controls the moving mechanism 4 and a control mechanism 7 that controls the supply mechanism 2.

  The coating head 1 has a function of coating a coating material on a coating surface 100 of a coating object 10 such as a substrate. Here, a structural example of the coating head 1 will be described with reference to FIG. FIG. 2 is a schematic front view showing a structural example of the coating head 1. Note that a mechanism for rotating the coating head 1 is not necessarily provided.

  As shown in FIG. 2, the coating head 1 includes a main shaft 11 and a plurality of coating regions 12 provided so as to be separated along the length direction of the main shaft 11. The end of the main shaft 11 is connected to the moving mechanism 3. By moving the main shaft 11 along one direction of the coating surface 100 by the moving mechanism 3, the coating head 1 can be moved.

  Furthermore, a structural example of the application region 12 will be described with reference to FIGS. 3 and 4. FIG. 3 is an enlarged view of one application region 12, and FIG. 4 is a schematic cross-sectional view of the application region 12 along line XY in FIG. The application region 12 has a columnar outer peripheral surface 12 a provided along the side surface of the main shaft 11. For example, the coating material 20 is supplied to the outer peripheral surface 12 a via the needle 22 of the syringe pump 21 that houses the coating material 20. Thereafter, the coating material 20 is supplied between the coating head 1 and the coating surface 100 along the outer peripheral surface 12a. Further, the coating head 1 has a groove 11 a between the plurality of coating regions 12.

  A meniscus column 31 is formed between the application region 12 and the application object 10. The meniscus column 31 is a columnar body having an arcuate curved surface 31a. The shape of the meniscus column 31 varies depending on, for example, the gap between the application region 12 and the application surface 100 of the application object 10, the properties of the application material 20 (viscosity, surface tension, etc.), the supply amount of the application material 20, and the like. To do. In the coating head 1 shown in FIGS. 2 to 4, a plurality of strip-shaped coating patterns can be formed for each coating region 12. The above is the description of the coating head 1.

  The supply mechanism 2 accommodates the coating material 20. The supply mechanism 2 has a function of supplying the coating material 20 between the coating head 1 and the coating surface 100 of the coating object 10. For the supply mechanism 2, for example, a syringe pump capable of accurately discharging a minute amount of material can be used. Further, the method is not limited to this, and a method suitable for discharging a small amount of material may be used, for example.

  The moving mechanism 3 has a function of moving the coating head 1 along one direction of the coating surface 100. The moving mechanism 4 has a function of moving the application object 10 along one direction of the application surface 100. The moving mechanism 4 includes, for example, a roller 4a and a roller 4b that support the application object 10. The application target object 10 can be moved by arrange | positioning the application target object 10 on the roller 4a and the roller 4b, and rotating the roller 4a and the roller 4b in the same direction. In addition, it is not limited to this, You may comprise the moving mechanism 4 using the stage which supports the application target object 10 and can move up and down, right and left. The coating apparatus only needs to include at least one of the moving mechanism 3 and the moving mechanism 4.

  The control mechanism 5 has a function of controlling at least one of the moving speed and the moving direction of the coating head 1 of the coating material in accordance with the start and stop of the supply of the coating material between the coating head 1 and the coating target 10. . The control mechanism 6 has a function of controlling at least one of the moving speed and moving direction of the application object 10 in accordance with the start and stop of the supply of the application material between the application head 1 and the application object 10. If the moving mechanism 3 is not provided, the control mechanism 5 may not be provided. If the moving mechanism 4 is not provided, the control mechanism 6 may not be provided. The control mechanism 5 and the control mechanism 6 may be a single control mechanism.

  The control mechanism 7 has a function for controlling the start and stop of the supply of the coating material to and between the coating head 1 and the coating object 10 and a mechanism for controlling the supply speed of the coating material. The control mechanism 7, the control mechanism 5, and the control mechanism 6 may be a single control mechanism.

  The control mechanism 5 to the control mechanism 7 are configured using hardware using a processor or the like, for example. Each operation may be stored in a computer-readable recording medium such as a memory as an operation program, and each operation may be executed by appropriately reading out the operation program stored in the recording medium by hardware.

  Next, a coating method using the coating apparatus will be described with reference to FIGS. 5 to 8 are schematic diagrams for explaining an example of the coating method, (A) is a schematic top view, and (B) is a schematic sectional view.

  In an example of the coating method, first, as shown in FIGS. 5A and 5B, the coating head 1 and the coating surface 100 of the coating object 10 are overlapped. At this time, the gap between the coating head 1 and the coating surface 100 is appropriately set within a range of, for example, 50 μm to 1000 μm. Further, the coating material 20 is supplied from the supply mechanism 2 between the coating head 1 and the coating surface 100 to form a meniscus column.

  Next, as shown in FIGS. 6A and 6B, by moving at least one of the coating head 1 and the coating object 10 along one direction of the coating surface 100, A step of applying the coating material 20 from the region 10a to the region 10b is performed. When the application head 1 is moved, the supply mechanism 2 is also moved in the same manner. Here, the application material 20 is applied by moving the application object 10 in the X direction.

  After applying the coating material 20 to the region 10b, the coating material 20 is replenished between the coating head 1 and the coating surface 100 while stopping at least one of the coating head 1 and the coating object 10 on the region 10b, or Between the coating head 1 and the coating surface 100 while moving at a speed slower than at least one moving speed of the coating head 1 and the coating object 10 in the step of coating the coating material along one direction of the coating surface 100. A step of replenishing the coating material 20 is performed. Here, the movement of the coating object 10 by the moving mechanism 4 is stopped by the control mechanism 6.

  The timing of replenishing the coating material 20 is controlled by the control mechanism 7, for example. For example, the coating material 20 may be replenished when the length of the coating pattern in the coating direction exceeds a reference value. Further, the coating material 20 may be replenished when the width of the meniscus column in the coating direction falls below the reference value. When the width of the meniscus column is narrowed, the width of the coating pattern is likely to change. The state of the coating pattern and the width of the meniscus column can be measured using, for example, an image sensor.

  After the coating material 20 is replenished, the coating operation is restarted. As shown in FIGS. 7A and 7B, in the X direction of the coating surface 100 at a speed faster than at least one moving speed of the coating head 1 and the coating object 10 in the step of replenishing the coating material. A process of applying the coating material 20 from the region 10b to the region 10c of the coating surface 100 is performed by moving at least one of the coating head 1 and the coating target 10 along the direction. At least one moving speed of the coating head 1 and the coating object 10 in this step may be the same as at least one moving speed of the coating head 1 and the coating object 10 in the step of applying the coating material.

  In addition, when the application of the coating material 20 is continued, the step of replenishing the coating material 20 shown above and the step of restarting the coating thereafter may be repeated. Thereby, for example, as shown in FIG. 8, a coating pattern 30 having a region 30a and a region 30b extending along one direction of the coating surface from the end of the region 30a can be formed. The length of the region 30a in the application direction is preferably 100 mm or less, for example. If the length of the region 30a exceeds 100 mm, it becomes difficult to control the coating pattern depending on the relationship between the supply amount and consumption amount of the coating material 20. The thickness of the region 30a is appropriately set depending on the type of film to be formed. Further, the thickness of the region 30b is larger than the thickness of the region 30a. For this reason, the region 30b is a region where the photoelectric conversion efficiency is low or does not contribute to the photoelectric conversion. Therefore, the length of the region 30b is preferably as short as possible. The length of the region 30b is shorter than the region 30a, and can be, for example, 5 mm or more and 15 mm or less.

  As described above, in the coating method using the coating apparatus of the present embodiment, coating is performed between the coating head and the coating object while at least one of the coating head and the coating object is stopped or decelerated during the coating. Refill material. Thereby, even if it is a case where it has a length exceeding 100 mm, for example, the dispersion | variation in the width | variety and thickness of a coating pattern is suppressed, and a coating precision can be raised.

  For example, when the coating material is not replenished during the coating, the width of the coating pattern is gradually narrowed, that is, the coating pattern is thinned. In addition, the coating pattern gradually becomes thinner. The above phenomenon is particularly problematic when a coating pattern having a length exceeding 100 mm is formed. Further, when the coating material is applied while constantly supplying the coating material, the central portion is thicker than the end portion of the coating pattern in the direction perpendicular to the coating direction. That is. Variations in the thickness of the coating pattern occur.

  On the other hand, as in the coating method of this embodiment, a region having a length exceeding 100 mm is obtained by replenishing the coating material while stopping or slowing down at least one of the coating head and the coating target in the middle of coating. The width and thickness of the coating pattern can be kept within a certain range.

  In addition, the coating method of this embodiment is not limited to said method. Another example of the coating method will be described with reference to FIGS. 9 and 10 are schematic views for explaining another example of the coating method, (A) is a schematic top view, and (B) is a schematic cross-sectional view.

  In another example of the coating method, similarly to the above coating method example, the coating head 1 and the coating surface 100 of the coating object 10 are overlapped, and the coating material is applied between the coating head 1 and the coating surface 100 from the supply mechanism 2. 20 is supplied. Next, as shown in FIGS. 9A and 9B, the application object 10 is moved along the X direction of the application surface 100, and the application head 1 is placed on the side opposite to the X direction of the application surface 100. By moving in the Y direction, a step of applying the coating material 20 from the region 10a to the region 10b of the coating surface 100 is performed.

  After applying the coating material 20 to the region 10b, the coating head 1 and the coating object 10 are moved in the X direction on the region 10b as shown in FIGS. 10A and 10B. And a step of replenishing the coating material 20 between the coating surface 100 and the coating surface 100. The method for controlling the timing of replenishing the coating material 20 is the same as the above method. At this time, it is preferable that the moving speeds of the coating head 1 and the coating object 10 are the same. Thereby, the length of the area | region 30b of the coating pattern 30 finally formed can be made small.

  After the coating material 20 is replenished, the coating operation is restarted. The process of applying the coating material 20 from the region 10a to the region 10b of the coating surface 100 is performed by moving the coating object 10 in the X direction and moving the coating head 1 in the Y direction.

  In addition, when continuing application | coating of the coating material 20, what is necessary is just to perform repeatedly the process of replenishing the coating material 20 similarly to an example of the said coating method, and the process of restarting application | coating after that. As described above, the coating pattern 30 having the region 30a and the region 30b can be formed as in FIG.

  In another example of the application method, the application target can be moved at a constant speed by moving not only the application object but also the application head, so that the movement control of the application object is facilitated.

  Note that the gap between the coating head 1 and the coating surface 100 of the coating object 10 can be changed by the moving mechanism 4. A structural example of a moving mechanism capable of changing the gap will be described with reference to FIG.

  The moving mechanism 4 shown in FIG. 11 has a roller 4a and a roller 4b. The roller 4a has a function of maintaining the tension applied to the application target object 10 within a certain range. The roller 4 b has a function of controlling the gap between the coating head 1 and the coating object 10. Each of the roller 4 a and the roller 4 b has an eccentric cam 41. The eccentric cam 41 has a function of changing the rotation shafts of the rollers 4 a and 4 b from the rotation shaft 40.

  In the moving mechanism 4 shown in FIG. 11, the gap between the coating head 1 and the coating object 10 can be controlled by changing the rotation axis of the roller by the eccentric cam 41. Note that the number of drive shafts of the coating head 1 can be reduced by combining with other examples of the coating method.

(Second Embodiment)
In the present embodiment, an example of a photoelectric conversion element that can be manufactured using the coating apparatus and the coating method of the first embodiment will be described.

  FIG. 12 is a schematic top view illustrating a structural example of a photoelectric conversion element. The photoelectric conversion element illustrated in FIG. 12 includes a plurality of strip-shaped cells 52 provided on a substrate 51. Note that a sealing portion may be provided so as to seal the plurality of cells 52.

  Examples of the substrate 51 include inorganic materials such as alkali-free glass and quartz glass, polyethylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyamide, polyamideimide, liquid crystal polymer, cycloolefin polymer, and other plastics, high A substrate such as a molecular film can be used. The substrate 51 is capable of forming an electrode, and is preferably hardly deteriorated by heat or an organic solvent. When light is incident through the substrate 51, the substrate 51 has translucency. Moreover, it is not limited to this, For example, a stainless steel (SUS) board | substrate, a silicon substrate, a metal substrate etc. can be used. At this time, at least a part of the plane of the substrate 51 preferably has an insulating surface. The thickness of the substrate 51 is not particularly limited as long as it has sufficient strength to support other components.

  When the photoelectric conversion element is a solar cell module, the cells 52 are electrically connected in series with each other. As a result, the output voltage can be increased. The number of cells 52 is not limited to the number shown in FIG. The cell 52 has at least a pair of electrodes and a photoactive layer provided between the pair of electrodes, for example.

  Further, a structural example of the cell 52 will be described with reference to FIGS. 13 to 15 are schematic views showing structural examples of cells. 13 is a schematic plan view showing a part of the cell, FIG. 14 is a schematic sectional view taken along line X1-Y1 in FIG. 13, and FIG. 15 is a schematic sectional view taken along line X2-Y2 in FIG. .

  A cell 52 illustrated in FIGS. 13 to 15 includes an electrode 521, an intermediate layer 522, a photoactive layer 523, an intermediate layer 524, and an electrode 525. The photoactive layer 523 has a function as a photoelectric conversion layer having a function of performing charge separation by energy of light such as irradiated sunlight.

  The electrode 521 is provided on the substrate 51. Alternatively, the plurality of electrodes 521 are preferably separated from each other. Examples of the electrode 521 include metal oxide materials such as indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), tin oxide containing fluorine (FTO), indium / zinc / oxide, gold, platinum, and silver. Metal materials such as copper, aluminum, molybdenum, titanium, tungsten, manganese, cobalt, nickel, and tin can be used. When light is incident through the substrate 51, the electrode 521 has a light-transmitting property, and in particular, ITO or FTO is preferably used. Further, as an electrode material, polyaniline and a derivative thereof, which is an organic conductive polymer, polythiophene and a derivative thereof, or the like may be used. The electrode 521 is formed by forming a film of the above material by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a plating method, a coating method, or the like. The electrode 521 may be a single layer or a stacked layer.

  The intermediate layer 522 is provided over the electrode 521. The intermediate layer 522 functions as one of an electron transport layer and a hole transport layer.

  The hole transport layer has a function of efficiently transporting holes, a function of preventing the disappearance of excitons generated near the interface of the photoactive layer 523, and the like. As the hole transport layer, a polythiophene polymer such as PEDOT / PSS (poly (3,4-ethylenedioxythiophene) -poly (styrenesulfonate)), or an organic conductive polymer such as polyaniline or polypyrrole can be used. . Further, an inorganic material such as molybdenum oxide or tungsten oxide may be used for the hole transport layer. An inorganic material such as molybdenum oxide is formed using, for example, a vacuum evaporation method. In addition, an inorganic material film can be formed by applying a precursor coating solution and then reacting it by heating or the like.

  The organic conductive polymer is formed using, for example, a coating method. For example, after forming a coating layer having a desired thickness made of a material applicable to the hole transport layer by a meniscus coating method, the hole transport layer can be formed by heating and drying with a hot plate or the like.

  The electron transport layer has a function of blocking holes and efficiently transporting only electrons, a function of preventing the disappearance of excitons (excitons) generated at the interface with the photoactive layer 523, and the like. As the electron transport layer, for example, a metal oxide or an organic material can be used. Examples of the metal oxide include amorphous titanium oxide obtained by hydrolyzing titanium alkoxide using a sol-gel method. As the organic material, polyethyleneimine or a derivative thereof is used. The electron transport layer is formed using, for example, a vacuum deposition method or a coating method.

  The photoactive layer 523 is provided over the intermediate layer 522. The photoactive layer 523 includes a region 523a and a region 523b thicker than the region 523a. As the photoactive layer 523, for example, a bulk heterojunction photoactive layer can be used. The bulk heterojunction type photoactive layer has a micro-layer separation structure of a p-type semiconductor and an n-type semiconductor mixed in the photoactive layer. In the photoelectric conversion element, the mixed p-type semiconductor and the n-type semiconductor form a pn junction having a nano-order size in the photoactive layer 523, and use photocharge separation that occurs at the junction surface when light enters. A current can be obtained. At least one of the p-type semiconductor and the n-type semiconductor may be an organic semiconductor.

  A p-type semiconductor is composed of a material having an electron donating property. Examples of p-type semiconductors include polythiophene and derivatives thereof, polypyrrole and derivatives thereof, pyrazoline derivatives, arylamine derivatives, stilbene derivatives, triphenyldiamine derivatives, oligothiophene and derivatives thereof, polyvinylcarbazole and derivatives thereof, polysilane and derivatives thereof, side Polysiloxane derivatives having an aromatic amine in the chain or main chain, polyaniline and derivatives thereof, phthalocyanine derivatives, porphyrin and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, and the like can be used. Moreover, these copolymers may be used, for example, a thiophene-fluorene copolymer, a phenylene ethynylene-phenylene vinylene copolymer, or the like may be used.

  As the p-type semiconductor, for example, polythiophene which is a conductive polymer having π conjugation and a derivative thereof can be used. Polythiophene and its derivatives can ensure excellent stereoregularity and have relatively high solubility in a solvent. Polythiophene and derivatives thereof are not particularly limited as long as they are compounds having a thiophene skeleton.

  Specific examples of polythiophene and derivatives thereof include polyalkylthiophenes such as poly-3-methylthiophene, poly-3-butylthiophene, poly-3-hexylthiophene, poly-3-octylthiophene, poly-3-decylthiophene, poly-3-dodecylthiophene, etc. Polyarylthiophene such as poly-3-phenylthiophene and poly-3- (p-alkylphenylthiophene); poly-3-butylisothionaphthene, poly-3-hexylisothionaphthene, poly-3-octylisothionaphthene, poly-3- And polyalkylisothionaphthene such as decylisothionaphthene; polyethylenedioxythiophene and the like.

  PCDTBT (poly [N-9 "-hepta-decanyl-2,7-carbazole-alt-5,5- (4 ', 7'-di-2), which is a copolymer of carbazole, benzothiadiazole and thiophene, is also used. Derivatives such as -thienyl-2 ′, 1 ′, 3′-benzothiadiazole)]) may be used, and the use of the above derivatives can increase the photoelectric conversion efficiency.In addition, PTB7 ([poly {4 , 8-bis [(2-ethylhexyl) oxy] benzo [1,2-b: 4,5-b ′] dithiophene-2,6-diyl-lt-alt-3-fluoro-2-[(2-ethyl Hexyl) carbonyl] thieno [3,4-b] thiophene-4,6-diyl}]).

  These conductive polymers are formed by applying a dispersion liquid dispersed in a solvent. Accordingly, a photoelectric conversion element having a large area can be manufactured at low cost by using an inexpensive method using a coating method or the like.

  An n-type semiconductor is composed of a material having an electron-accepting property. As the n-type semiconductor, for example, fullerene and derivatives thereof are preferably used. The fullerene derivative is not particularly limited as long as it is a derivative having a fullerene skeleton. For example, derivatives composed of C60, C70, C76, C78, C84, etc. as the basic skeleton can be given. In the fullerene derivative, carbon atoms in the fullerene skeleton may be modified with an arbitrary functional group, and these functional groups may be bonded to each other to form a ring. Fullerene derivatives also include fullerene bonded polymers. A fullerene derivative having a functional group with high affinity for the solvent and high solubility in the solvent is preferred.

  Examples of the functional group in the fullerene derivative include hydrogen atom; hydroxyl group; halogen atom such as fluorine atom and chlorine atom; alkyl group such as methyl group and ethyl group; alkenyl group such as vinyl group; cyano group; methoxy group and ethoxy group. Alkoxy groups such as phenyl groups, aromatic hydrocarbon groups such as naphthyl groups, and aromatic heterocyclic groups such as thienyl groups and pyridyl groups. Specific examples include hydrogenated fullerenes such as C60H36 and C70H36, oxide fullerenes such as C60 and C70, and fullerene metal complexes. Among the above-described compounds, it is particularly preferable to use 60PCBM ([6,6] -phenyl C61 butyric acid methyl ester) or 70PCBM ([6,6] -phenyl C71 butyric acid methyl ester) as the fullerene derivative.

  When using unmodified fullerene, it is preferable to use C70. Fullerene C70 has high photocarrier generation efficiency and is suitable for organic thin-film solar cells.

  The mixing ratio (n: p) of the n-type semiconductor and the p-type semiconductor in the photoactive layer is preferably about 1: 1 when the content of the n-type semiconductor is a P3HT system. When the p-type semiconductor is a PCDTBT system, it is preferably about 4: 1.

  In order to apply the organic semiconductor, for example, a dispersion is prepared by dispersing in an solvent. Examples of the solvent include toluene, xylene, tetralin, decalin, mesitylene, n-butylbenzene, sec-butylbenzene, tert-butylbenzene and other unsaturated hydrocarbon solvents, and chlorobenzene, dichlorobenzene, trichlorobenzene and the like. Aromatic hydrocarbon solvents, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, chlorohexane, bromohexane, chlorocyclohexane and other halogenated saturated hydrocarbon solvents, tetrahydrofuran, tetrahydropyran and other ethers Is mentioned. In particular, a halogen-based aromatic solvent is preferable. These solvents can be used alone or in combination.

  The coating apparatus and the coating method of the above embodiment can be used for forming the photoactive layer 523, for example. At this time, the photoactive layer 523 includes a region 523a corresponding to the region 30a of the coating pattern 30 and a region 523b corresponding to the region 30b. Alternatively, the above coating method may be used for forming the intermediate layer 522 and the intermediate layer 524. When the coating apparatus or coating method of the above embodiment is not used for forming the photoactive layer, for example, spin coating method, dip coating method, casting method, bar coating method, roll coating method, wire bar coating method, spray method, screen, etc. Printing, gravure printing method, flexographic printing method, offset printing method, gravure / offset printing, dispenser application, nozzle coating method, capillary coating method, ink jet method and the like may be used alone or in combination.

  The intermediate layer 524 is provided on the photoactive layer 523. The intermediate layer 524 overlaps with the intermediate layer 522 with the photoactive layer 523 interposed therebetween. The intermediate layer 524 functions as the other of the electron transport layer and the hole transport layer.

  The electrode 525 is provided over the photoactive layer 523 with the intermediate layer 522 and the intermediate layer 524 interposed therebetween. The plurality of electrodes 525 are preferably separated from each other. The electrode 525 is electrically connected to the electrode 521 of the adjacent next-stage cell 52.

  As the electrode 525, for example, a metal, a metal oxide, a conductive polymer, or the like can be used. When light is incident through the electrode 525, the electrode 525 has a light-transmitting property.

  The electrode 525 is, for example, platinum, gold, silver, copper, nickel, cobalt, iron, manganese, tungsten, titanium, zirconium, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, rubidium, cesium, calcium, magnesium Metals such as barium, samarium and terbium, alloys containing them, conductive metal oxides such as indium-zinc oxide (IZO), conductive polymers such as PEDOT / PSS, and carbon materials such as graphene are used. . Nano conductive materials such as silver nanowires, gold nanowires, and carbon nanotubes can also be used by mixing them with the aforementioned materials. The electrode 525 is formed by forming a film of the above material by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a plating method, a coating method, or the like. The above is the description of the structural example of the cell 52. Note that the structure of the cell 52 may be a structure in which the charge extraction direction is opposite to the above structure.

  As described above, a photoelectric conversion element can be manufactured using the coating apparatus and the coating method of the embodiment. The photoelectric conversion element has high photoelectric conversion efficiency. The coating apparatus and the coating method of the embodiment are not limited to solar cells, and for example, multiple strip pattern coating as shown in FIG. 12 such as an organic EL (Electro Luminescence: EL) type illumination or display is useful. Applicable to all technologies. Further, the present invention can be applied to all techniques that make it useful to apply a single strip-shaped pattern instead of multiple.

  In addition, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

Example 1
A substrate in which an ITO film having a thickness of 150 nm was formed as a first electrode on a substrate of a PEN (polyethylene naphthalate) film having a thickness of 200 μm was prepared. Next, PEIE (polyethyleneimine, 80% ethoxylate) having a thickness of about 1 nm was formed as a first intermediate layer.

  Next, the material of the photoactive layer was applied on the first intermediate layer using a coating head made of SUS303. As a material for the photoactive layer, 1 ml of monochlorobenzene was added to PTB7 ([poly {4,8-bis [(2-ethylhexyl) oxy] benzo [1,2-b: 4,5-b ′] dithiophene-2,6. -Diyl-lt-alt-3-fluoro-2-[(2-ethylhexyl) carbonyl] thieno [3,4-b] thiophene-4,6-diyl}]), 8 mg, PC70BM (/ [6 6] A coating solution in which 12 mg of phenyl C71 methyl butyrate ester) was dispersed was used.

  As the coating head, a coating head having 23 coating areas was used. The width of the application area is 12.0 mm. Moreover, the width | variety of the groove part between application | coating areas is 1.2 mm, and the depth is 0.5 mm. The gap between the coating head and the substrate was 0.88 mm (880 μm).

  A syringe pump was disposed as a supply mechanism in each of the coating regions, and 45 μl of the material of the photoactive layer was discharged per coating region to form 23 meniscus columns. At this time, the width (also referred to as nip length) of the meniscus column in the coating direction was about 5 mm as a result of measurement using a camera image.

  Next, the substrate was moved at a speed of 10 mm / s to start application of the photoactive layer material. Thereafter, when the photoactive layer material was applied to a length of 100 mm, the width of the meniscus column in the coating direction was reduced to about 4.3 mm. At this point, the movement of the substrate was temporarily stopped, and 6.4 μl of the photoactive layer material was replenished to each of the coating areas. As a result, the width of the meniscus column in the coating direction returned to about 5 mm.

  Next, the movement of the substrate was resumed at a speed of 10 mm / s to apply the photoactive layer material. Thereafter, the photoactive layer material was applied by repeating the replenishment operation of the photoactive layer material and the moving operation of the substrate to form the photoactive layer. In the photoactive layer, in the first region having a length of about 90 mm corresponding to the region 30a, the width was about 12.5 mm, the thickness was about 100 nm, and the coating pattern was uniform in both width and thickness. In the second region having a length of about 10 mm corresponding to the region 30b, the thickness was about 200 nm.

Thereafter, a molybdenum trioxide film having a thickness of 5 nm is formed as a second intermediate layer on the photoactive layer by a vapor deposition method, and a silver film having a thickness of 150 nm is formed as a second electrode on the second intermediate layer by a vapor deposition method. An organic thin film solar cell module was produced by forming a film. It was 6.7% when the photoelectric conversion efficiency was measured using the solar simulator of AM1.5G and 1000 W / m < ² > for the produced organic thin film solar cell module.

(Example 2)
An organic thin film solar cell module was produced by the same method and materials as in Example 1 except for the method for forming the photoactive layer. The photoactive layer was formed as follows.

  First, the coating head was arranged with a gap of 0.88 mm with respect to the substrate. Next, a syringe pump was arranged as a supply mechanism in each of the application areas, and 45 μl of the material of the photoactive layer was discharged per application area to form 23 meniscus columns. At this time, the width of the meniscus column in the coating direction was about 5 mm as a result of measurement using a camera image.

  Next, the photoactive layer is moved by moving the substrate in the first direction at a speed of 5 mm / s and simultaneously moving the coating head in the second direction opposite to the first direction at a speed of 5 mm / s. The material was applied. At this time, the relative speed of the substrate and the coating mechanism was 10 mm / s, which was the same as in Example 1, and the thickness of the coating material was also about 100 nm.

  At the time when the relative position of the substrate and the coating head was 100 mm apart (the absolute position of the substrate was +50 mm and the absolute position of the coating head was −50 mm), the width of the meniscus column in the coating direction was reduced to about 4.3 mm. At this point, the coating head and the substrate were moved in the first direction at a speed of 5 mm / s. At this time, the relative speed between the substrate and the coating head is 0 mm / s. At the same time, 6.4 μl of coating material was replenished to each of the coating areas. At this time, the width of the meniscus column in the coating direction was restored to about 5 mm.

  When the absolute position of the coating head returns to ± 0 mm, the same as when coating starts, the substrate is moved in the first direction at a speed of 5 mm / s, and the coating head is moved in the second direction at a speed of 5 mm / s. The material of the photoactive layer was applied. A photoactive layer was formed by repeating the above operation. The width of the first region having a length of about 90 mm was about 12.5 mm, the thickness was about 100 nm, and the coating pattern was uniform in both width and thickness. The thickness of the second region having a length of about 10 mm was about 200 nm.

  Furthermore, it was 6.9% when the photoelectric conversion efficiency of the produced organic thin film solar cell module was measured by the method similar to Example 1. FIG.

(Comparative Example 1)
An organic thin film solar cell module was produced by the same method and materials as in Example 1 except for the method for forming the photoactive layer. The photoactive layer was formed as follows.

  First, the coating head was arranged with a gap of 0.88 mm with respect to the substrate. Next, a syringe pump was arranged as a supply mechanism in each of the application areas, and 45 μl of the material of the photoactive layer was discharged per application area to form 23 meniscus columns. At this time, the width of the meniscus column in the coating direction was about 5 mm as a result of measurement using a camera image.

  Next, the substrate was moved at a speed of 10 mm / s to start application of the photoactive layer material. The photoactive layer was formed by moving the substrate to the edge of the substrate without performing additional supply of the coating solution in the middle. Furthermore, it was 0.8% when the photoelectric conversion efficiency of the organic thin-film solar cell module was measured similarly to the Example. This is because the second electrode is short-circuited with the first electrode because the photoactive layer becomes thinner along the coating direction.

(Comparative Example 2)
An organic thin film solar cell module was produced by the same method and materials as in Example 1 except for the method for forming the photoactive layer. The photoactive layer was formed as follows.

  First, the coating head was arranged with a gap of 0.88 mm with respect to the substrate. Next, a syringe pump was arranged as a supply mechanism in each of the application areas, and 45 μl of the material of the photoactive layer was discharged per application area to form 23 meniscus columns. At this time, the width of the meniscus column in the coating direction was about 5 mm as a result of measurement using a camera image.

  Next, while moving the substrate at a speed of 10 mm / s, the photoactive layer of the photoactive layer is continuously discharged at a discharge speed such that 6.4 μl of the material of the photoactive layer is discharged while the substrate is moved 100 mm by the supply mechanism. The photoactive layer was formed by applying the photoactive layer material while replenishing the material. Furthermore, it was 3.2% when the photoelectric conversion efficiency of the organic thin-film solar cell module was measured similarly to the Example. This is because the variation in the thickness of the photoactive layer is increased by constantly supplying the material of the photoactive layer.

  As mentioned above, the organic thin film solar cell module which has the photoelectric conversion element of a present Example has a photoelectric conversion efficiency higher than the organic thin film solar cell module of a comparative example.

  DESCRIPTION OF SYMBOLS 1 ... Coating head, 2 ... Supply mechanism, 3 ... Movement mechanism, 4 ... Movement mechanism, 4a ... Roller, 4b ... Roller, 5 ... Control mechanism, 6 ... Control mechanism, 7 ... Control mechanism, 10 ... Application object, 10a ... Area, 10b ... Area, 10c ... Area, 11 ... Main shaft, 11a ... Groove, 12 ... Application area, 12a ... Outer peripheral surface, 20 ... Application material, 21 ... Syringe pump, 22 ... Needle, 30 ... Application pattern, 30a ... Area, 30b ... Area, 31 ... Meniscus column, 31a ... Curved surface, 40 ... Rotating shaft, 41 ... Eccentric cam, 51 ... Substrate, 52 ... Cell, 521 ... Electrode, 522 ... Intermediate layer, 523 ... Photoactive layer, 523a ... Area, 523b ... area, 524 ... intermediate layer, 525 ... electrode.

Claims (5)

Supplying a first amount of a coating material between the coating head and the coating surface by superimposing a coating head and a coating surface of a coating object;
After supplying the coating material, the coating material is applied from the first region to the second region of the coating surface by moving the coating head or the coating object along one direction of the coating surface. And a process of
After applying the coating material to the second region, the first amount is applied between the coating head and the coating surface while stopping the coating head or the coating object on the second region. The coating head along one direction of the coating surface at a speed slower than the moving speed of the coating head or the object to be coated in the step of replenishing the second amount of coating material with a smaller amount or coating the coating material Or replenishing the second amount of coating material between the coating head and the coating surface while moving the coating object;
After supplemented with the second amount of the coating material, along one direction of the coated surface at a speed higher than the moving speed of the coating head or the object to be coated in the step of replenishing the second amount of the coating material And applying the coating material from the second region to the third region of the coating surface by moving the coating head or the coating object. A step of superposing a coating head and a coating surface of a coating object, and supplying a coating material between the coating head and the coating surface;
The coating head is moved along a first direction of the coating surface, and the coating object is moved along a second direction opposite to the first direction, whereby the first of the coating surface is moved. Applying the coating material from the region to the second region;
After applying the coating material to the second region, the coating material is moved between the coating head and the coating surface while moving the coating head and the coating object along the second direction. A replenishment step;
After replenishing the coating material, the second area of the coating surface is obtained by moving the coating head along the first direction and moving the coating target along the second direction. And a step of applying the coating material from the first region to the third region.   The coating method according to claim 2, wherein in the step of replenishing the coating material, movement speeds of the coating head and the coating object are the same. An application head;
A supply mechanism for containing a coating material and supplying the coating material between the coating head and a coating surface of a coating object;
As overlapped portion between the coating head and the coated surface is moved in one direction of the coated surface, and a moving mechanism for moving along at least one prior Symbol first direction of the coating head and the coating object ,
Before at least one of the coating head and the coating object moves, a first amount of coating material is supplied between the coating head and the coating surface, and the overlapping portion is a first portion of the coating surface. The coating head by the supply mechanism is replenished with a second amount of coating material smaller than the first amount between the coating head and the coating surface after moving from a region to a second region. A first control mechanism for controlling the start and stop of the supply of the coating material between the coating surface and the coating surface;
When the second amount of coating material is replenished, the coating head or the coating object stops on the second area, or when the second amount of coating material is replenished The application head or the application object along the one direction at a speed slower than the moving speed of the application head or the application object when the overlapping portion moves from the first area to the second area. A second control for controlling at least one of the moving direction and the moving speed of at least one of the coating head and the coating object by the moving mechanism in accordance with the start and stop of the supply of the coating material A coating apparatus comprising: a mechanism; The moving mechanism includes a first roller and a second roller that support the application object,
The coating apparatus according to claim 4, wherein the first roller and the second roller have an eccentric cam for changing a gap between the coating head and the coating object.

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