JP6034429B2 - Photoelectric conversion device and method for manufacturing photoelectric conversion device - Google Patents

Description

  The invention of the embodiments relates to a photoelectric conversion device and a method for manufacturing the photoelectric conversion device.

  Organic thin-film solar cells, which are one type of photoelectric conversion device, are lighter and more flexible than, for example, silicon solar cells, and can be manufactured at low cost using a coating method. Attention has been paid.

  An organic thin film solar cell includes a photoelectric conversion cell that is provided between an anode and a cathode and includes a photoelectric conversion layer that forms a pn junction. In organic thin-film solar cells, irradiated light such as sunlight is absorbed by an active layer to generate excitons by photoexcitation, diffuse to the pn junction interface, and perform charge separation. Electricity is generated by moving holes to the anode side.

  In order to improve the photoelectric conversion efficiency of the photoelectric conversion device per unit area, the area of a region (also referred to as a photoelectric conversion region) that contributes to photoelectric conversion by providing as many photoelectric conversion cells as possible on a substrate having a predetermined area Is preferably increased. However, in order to form a plurality of photoelectric conversion cells on the same substrate, it is necessary to design with the interval between the photoelectric conversion cells wider than a predetermined interval in consideration of patterning accuracy in the photoelectric conversion layer forming step. .

JP 2012-156423 A JP2013-016668A

  The problem to be solved by the invention of the embodiment is to improve the photoelectric conversion efficiency of the photoelectric conversion device per unit area.

  The photoelectric conversion device according to the embodiment includes a substrate having a first region and a second region surrounding the first region, a first electrode provided on the first region, and a first electrode And a second electrode provided to be in contact with the upper surface of the photoelectric conversion layer and to be superimposed on the first electrode with the photoelectric conversion layer interposed therebetween. A first partition wall portion provided on the first region so as to be in contact with the side surface of the photoelectric conversion layer, and extending from the first partition wall portion to the second region, and on the second region A partition including a second partition including a void, and a sealing portion provided to seal the element and in contact with the second region in the void.

It is a schematic diagram which shows the structural example of a photoelectric conversion apparatus. It is a schematic diagram which shows the structural example of a photoelectric conversion apparatus. It is a schematic diagram which shows the structural example of a photoelectric conversion apparatus. It is an enlarged view of a partition part. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a schematic diagram in the case of forming a photoelectric conversion layer by the coating method using a coating device. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a plane schematic diagram for demonstrating the example of the manufacturing method of a photoelectric conversion apparatus. It is a schematic diagram which shows the example of a photoelectric conversion panel.

  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)
1 to 3 are schematic diagrams illustrating structural examples of the photoelectric conversion device, FIG. 1 is a plan view, FIG. 2 is a cross-sectional view taken along line A1-B1 in FIG. 1, and FIG. It is sectional drawing of line segment A2-B2.

  The photoelectric conversion device shown in FIGS. 1 to 3 includes a substrate 1, an element portion 2 having an electrode 21, a photoelectric conversion layer 22, and an electrode 23, a partition wall portion 3 (3a, 3b), a sealing portion 4, And a substrate 5. In FIG. 1, the substrate 5 is omitted for convenience.

  The board | substrate 1 was provided in the 1st area | region 1a, the 2nd area | region 1b surrounding 1st area | region 1a, and the 2nd area | region 1b outer side (opposite the contact part with 1st area | region 1a). And a third region 1c. The first region 1a is a region for providing the element portion 2, and is a photoelectric conversion region including a region contributing to photoelectric conversion. The second region 1b and the third region 1c are peripheral regions. The substrate 1 has a function as a support substrate, for example. In FIG. 1, the third region 1c is provided so as to surround the second region 1b. However, for example, the third region 1c may be provided only in part of the outside of the second region 1b. Good.

  The element part 2 has a photoelectric conversion cell. For example, in FIG. 2, an overlapping portion of the electrode 21, the photoelectric conversion layer 22, and the electrode 23 may be regarded as one photoelectric conversion cell. At this time, the element unit 2 is regarded as having a plurality of photoelectric conversion cells (first photoelectric conversion cell to Nth (N is a natural number of 2 or more) photoelectric conversion cells) electrically connected in series. be able to.

  The electrode 21 is provided on the first region 1a. At this time, the electrode 21 may extend to the second region 1b or the third region 1c. The electrode 21 has a function as one of an anode and a cathode of the photoelectric conversion cell.

  The photoelectric conversion device shown in FIGS. 1 to 3 includes a plurality of electrodes 21 on a substrate 1. Another electrode serving as an electrode pad may be formed on the electrode 21 extending to the third region 1c. The number of electrodes 21 is not particularly limited.

  The photoelectric conversion layer 22 is provided on the electrode 21. In FIG. 1 and FIG. 2, a plurality of photoelectric conversion layers 22 are provided so as to be in contact with the upper surfaces of different electrodes 21 among the plurality of electrodes 21. The photoelectric conversion layer 22 may extend to the second region 1b and the third region 1c. The photoelectric conversion layer 22 has a function of performing charge separation by the energy of the irradiated light.

  The photoelectric conversion layer 22 includes, for example, a buffer layer 22a provided on the electrode 21, a photoactive layer 22b provided on the buffer layer 22a, and a buffer layer 22c provided on the photoactive layer 22b. The side surface of the buffer layer 22a, the side surface of the photoactive layer 22b, and the side surface of the buffer layer 22c may be continuous. The buffer layer 22a may be in contact with the side surface of the electrode 21 and the photoactive layer 22b may overlap the side surface of the electrode 21 with the buffer layer 22a interposed therebetween. Further, the photoactive layer 22 b may be in contact with the side surface of the electrode 21. A step may be provided between the photoactive layer 22b and the buffer layer 22c. Furthermore, the buffer layer 22a and the buffer layer 22c are not necessarily provided.

  The buffer layer 22a is an intermediate layer between the electrode 21 and the photoactive layer 22b, and the buffer layer 22c is an intermediate layer between the photoactive layer 22b and the electrode 23. One of the buffer layer 22a and the buffer layer 22c has a function as a hole transport layer, and the other has a function as an electron transport layer (or a hole block layer).

  The hole transport layer has a function of efficiently transporting holes and a function of preventing the disappearance of excitons generated near the interface of the photoactive layer 22b. The electron transport layer has a function of blocking holes and efficiently transporting only electrons, and a function of preventing the disappearance of excitons (excitons) generated at the interface with the photoactive layer 22b.

  The photoelectric conversion device illustrated in FIGS. 1 to 3 includes a plurality of photoelectric conversion layers 22 so as to be in contact with the upper surfaces of the electrodes 21 that are different from each other. The number of photoelectric conversion layers 22 is not particularly limited.

  The electrode 23 is provided on the photoelectric conversion layer 22. The electrode 23 has a function as the other of the anode and the cathode of the photoelectric conversion cell.

  The photoelectric conversion device illustrated in FIGS. 1 to 3 includes a plurality of electrodes 23 provided so as to be in contact with the top surfaces of the photoelectric conversion layers 22 that are different from each other among the plurality of photoelectric conversion layers 22. At this time, the electrode 23 constituting the Nth photoelectric conversion cell may extend from the first region 1a to the second region 1b. The electrode 23 constituting the (N-1) th photoelectric conversion cell is electrically connected to the electrode 21 constituting the Nth photoelectric conversion cell. Another electrode serving as an electrode pad may be formed on the electrode 23 extending to the third region 1c. The number of electrodes 23 is not particularly limited.

  For example, when the electrode 21 is a cathode, the buffer layer 22a functions as an electron transport layer. When the electrode 23 is an anode, the buffer layer 22c functions as a hole transport layer.

  The partition 3 is provided so as to extend in one direction of the substrate 1 in contact with the side surface of the photoelectric conversion layer 22. The extending direction of the partition walls 3 is preferably a direction parallel to the application direction of the photoelectric conversion layer 22, for example. Moreover, you may extend the partition part 3 in the direction perpendicular | vertical along the plane of the board | substrate 1 with respect to the juxtaposition direction of a photoelectric conversion cell. The partition wall 3 may extend from the first region 1a to the third region 1c. Note that “parallel” may include a state (substantially parallel) shifted by ± 10 degrees from the parallel direction.

  The photoelectric conversion device shown in FIGS. 1 to 3 includes a plurality of partition walls 3 so as to be in contact with the side surfaces of different photoelectric conversion layers 22. In other words, the partition 3 is provided so as to divide the plurality of photoelectric conversion layers 22. For example, the partition part 3 has the partition part 3a and the partition part 3b. The partition wall 3 a is provided in contact with the substrate 1 and is in contact with one of a pair of opposing side surfaces of the photoelectric conversion layer 22. The partition 3b is provided in contact with the electrode 21 and is in contact with the other of the pair of side surfaces. In addition, the number of the partition part 3 is not specifically limited, Both the partition part 3a and the partition part 3b do not necessarily need to be provided.

  The partition 3 preferably has one end provided in the third region 1c and the other end provided in the first region 1a or the second region 1b. That is, one end of the partition wall portion 3 extends to the third region 1c, and the other end does not extend to the third region 1c, but extends only to the first region 1a or the second region 1b. Since the fixing area between the substrate 1 and the sealing portion 4 can be increased, the adhesive strength between the substrate 1 and the sealing portion 4 can be increased.

  Further, as shown in FIG. 3, the partition wall portion 3 includes a first partition wall portion 31 provided on the first region 1a, and a second partition portion extending from the first partition wall portion 31 to the second region 1b. Partition wall portion 32 and a third partition wall portion 33 extending from the second partition wall portion 32 to the third region 1c. The 2nd partition part 32 and the 3rd partition part 33 are provided on the board | substrate 1, for example. Note that the third partition wall 33 is not necessarily provided.

  FIG. 4 is an enlarged view of the second partition wall 32. As shown in FIG. 4, the second partition wall 32 has a gap 320. In the gap portion 320, the sealing portion 4 is fixed to the substrate 1. Therefore, the adhesive strength between the substrate 1 and the sealing portion 4 can be increased. In addition, the 2nd partition part 32 does not necessarily need to be provided intermittently on both sides of the space | gap part 320, for example, may form the space | gap part 320 with a through-hole.

  The thickness of the partition wall 3 is appropriately set according to the thickness of the photoelectric conversion layer 22, for example. For example, the thickness of the partition wall 3 is preferably equal to or greater than the thickness of the photoelectric conversion layer 22, and more preferably equal to or greater than the sum of the thickness of the electrode 21 and the thickness of the photoelectric conversion layer 22. In addition, when the photoelectric conversion layer 22 is formed using a coating method, the coating layer of the material of the photoelectric conversion layer 22 often has a larger volume than the photoelectric conversion layer 22. It is preferably thicker than the thickness of the conversion layer 22, and more preferably thicker than the sum of the thickness of the electrode 21 and the thickness of the photoelectric conversion layer 22.

  The thickness of the partition wall 3 is preferably 0.5 μm or more and 10 μm or less, for example. Further, the height of the upper surface of the partition wall 3 is preferably equal to or higher than the height of the upper surface of the photoelectric conversion layer 22 or higher than the height of the upper surface of the photoelectric conversion layer 22. Thereby, the unnecessary spread of the photoelectric converting layer 22 can be suppressed more effectively.

  The width of the partition wall portion 3 in the direction perpendicular to the extending direction is preferably, for example, 10 μm or more and 1000 μm or less. If the width is less than 10 μm, the yield when the partition walls 3 are formed on the substrate 1 becomes poor. On the other hand, when the width exceeds 1000 μm, the area of the photoelectric conversion region becomes small. Moreover, the length of the partition part 3 in the extending direction is appropriately set so as to be longer than the photoelectric conversion cell according to the size of the photoelectric conversion cell.

It is preferable that the partition part 3 has insulation. Thereby, unnecessary current leakage through the partition 3 can be suppressed. For example, the volume resistivity of the partition wall 3 is preferably 1 × 10 ¹⁰ Ω or more. For example, when the electric resistance per 1 cm ² in the partition wall portion 3 having a thickness of 1 μm is 1 MΩ, and there is a potential difference of 1 V between the electrode 21 and the electrode 23, a current of the order of 1 μA flows per 1 cm ² .

  The sealing part 4 is provided so as to seal the element part 2. For example, the sealing portion 4 may be provided so as to seal at least the overlapping portion of the electrode 21, the photoelectric conversion layer 22, and the electrode 23. In the photoelectric conversion device shown in FIGS. 1 to 3, the sealing portion 4 is provided on the second region 1 b so as to surround the element portion 2. However, the sealing unit 4 may be provided so as to cover the element unit 2. Further, the sealing portion 4 is provided so as to be in contact with the second region 1b in the gap portion 320. Thereby, the adhesive strength of the sealing part 4 and the board | substrate 1 can be raised.

  The substrate 5 is provided on the sealing portion 4 so as to overlap the element portion 2. The substrate 5 has a function as a counter substrate, for example. The substrate 5 may be provided such that a recess is formed in the substrate 5 and the element portion 2 is positioned in the recess. For example, when forming the sealing part 4 so that the element part 2 may be covered, the board | substrate 5 does not necessarily need to be provided.

  As described above, the photoelectric conversion device of the present embodiment includes the first electrode, the photoelectric conversion layer, and the second electrode, and from the first region of the substrate to at least the second region along the photoelectric conversion layer. It has a partition part extending.

  As a cause of a decrease in photoelectric conversion efficiency in the photoelectric conversion device, for example, a decrease in aperture ratio can be given. In a solar cell including a translucent electrode without being limited to an organic thin film solar cell, for example, a plurality of photoelectric conversion cells having a width of 10 mm or more and 15 mm or less are electrically connected in series connection or parallel connection. Configure the conversion module. This is because the resistance value of the translucent electrode tends to be higher than the resistance value of the electrode made of metal. Further, a photoelectric conversion module is configured by electrically connecting a plurality of photoelectric conversion cells of about 10 to 15 in a series connection on a substrate having a side of 10 cm to 20 cm.

  When electrically connecting a plurality of photoelectric conversion cells in series connection, it is necessary to provide wiring from the first electrode having translucency to the second electrode in the uppermost layer. In order to provide a space for providing this wiring, a region that does not contribute to power generation increases, and the aperture ratio of the photoelectric conversion device decreases.

  For example, in CIGS and a-Si solar cells, the path of wiring is formed by using a scribing technique. However, scribing techniques are not effective for organic thin-film solar cells due to differences in light absorption characteristics and rigidity of materials. Therefore, in the organic thin film solar cell, particularly when a polymer organic material is used, a film constituting the photoelectric conversion layer is formed so that the photoelectric conversion layer in each photoelectric conversion cell is separated. For example, in the case where an organic material is used for the photoelectric conversion layer, the photoelectric conversion layer can be formed by dissolving the organic material in a solvent and applying it by using a coating method.

  The film forming method using the coating method has an advantage that the initial cost can be suppressed from the point that a vacuum apparatus is unnecessary, as compared with a film forming method such as an evaporation method or a sputtering method. However, when a plurality of photoelectric conversion cells are formed side by side, in the film forming method using the coating technique, the interval between the photoelectric conversion cells must be widened from the viewpoint of patterning accuracy. As a result, the solar cell module using the polymer organic material that can be produced by the coating technique needs to widen the interval between the photoelectric conversion cells, has the disadvantage that the aperture ratio is low and the photoelectric conversion efficiency is low. Have.

  On the other hand, in the photoelectric conversion device of this embodiment, when the photoelectric conversion layer is formed by using, for example, a coating method by providing the partition wall, the spread of the coating layer of the photoelectric conversion layer is suppressed. The interval between the photoelectric conversion cells including the electrode, the photoelectric conversion layer, and the second electrode can be reduced. Therefore, the area of the photoelectric conversion region can be increased, the aperture ratio can be increased, and the photoelectric conversion efficiency per unit area can be increased.

  An interval between a plurality of photoelectric conversion cells, that is, a space (non-photoelectric conversion unit) between one photoelectric conversion cell and another photoelectric conversion cell may be, for example, less than 4 mm, less than 2 mm, or even less than 1.2 mm. preferable. The aperture ratio of the photoelectric conversion device is preferably, for example, 75% or more, 80% or more, and more preferably 90% or more.

  In the photoelectric conversion device of the present embodiment, a gap is provided in a part of the second partition wall, and the substrate and the sealing part are in contact with each other in the gap, whereby the adhesive strength between the substrate and the sealing part is obtained. Can be increased.

  Next, an example of a method for manufacturing the photoelectric conversion device shown in FIGS. 1 to 4 will be described with reference to FIGS. 5 to 14 are schematic plan views for explaining an example of a method for manufacturing a photoelectric conversion device. Note that the description of the photoelectric conversion device illustrated in FIGS. 1 to 4 can be used as appropriate for portions common to the photoelectric conversion device illustrated in FIGS.

First, the electrode 21 is formed on the first region 1 a of the substrate 1. Examples of the substrate 1 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. A molecular film or the like can be used. In the case of plastics and polymer films, a composite film coated with an inorganic material such as SiO ₂ is used because of high moisture and oxygen permeability.

  The substrate 1 is capable of forming an electrode, and is preferably not easily altered by heat or an organic solvent. When light is incident through the substrate 1, the substrate 1 has translucency. Moreover, it is not limited to this, For example, stainless steel (SUS), a silicon substrate, a metal substrate etc. can be used. At this time, at least a part of the plane of the substrate 1 preferably has an insulating surface. The thickness of the substrate 1 is not particularly limited as long as it has sufficient strength to support other components.

  The electrode 21 is made of, for example, indium oxide, zinc oxide, tin oxide, indium tin oxide (ITO), tin oxide containing fluorine (Fluorine-doped Tin Oxide: FTO), indium / zinc / oxide, or the like. Metal oxide materials such as films (NESA etc.) produced using conductive glass, and metal materials such as gold, platinum, silver, copper, aluminum, molybdenum, titanium, tungsten, manganese, cobalt, nickel, tin Can be used. When light is incident through the substrate 1, the electrode 21 has translucency, 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 21 is formed by forming a film of the above material by, for example, a vacuum evaporation method, a sputtering method, an ion plating method, a plating method, a coating method, or the like.

  In the case of ITO, the thickness of the electrode 21 is preferably 30 nm or more and 300 nm or less. If it is thinner than 30 nm, the sheet resistance is increased and the photoelectric conversion efficiency is lowered. If it is thicker than 300 nm, the flexibility becomes low and cracking is likely to occur due to stress. The sheet resistance of the electrode 21 is preferably low, for example, 10Ω / □ or less. The electrode 21 may be a single layer or may be a stack of layers made of materials having different work functions.

  Next, as shown in FIG. 6, the partition 3 having the first partition 31, the second partition 32, and the third partition 33 is formed. The extending direction of the partition walls 3 is set in advance according to the application direction of the material of the photoelectric conversion layer 22 to be formed later.

  The third partition wall portion 33 has a function as a running portion when the material of the photoelectric conversion layer 22 is applied. It is preferable that the 3rd partition part 33 is extended in the upstream at the time of apply | coating the material of the photoelectric converting layer 22, ie, the starting point side of application | coating. When forming the photoelectric conversion layer 22 using a coating method, the coating width tends to shift particularly near the starting point. Therefore, the width of the photoelectric conversion layer 3 can be easily controlled by providing the third partition wall 33 on the starting point side of the application. Therefore, the interval between the photoelectric conversion cells can be reduced.

  The third partition wall 33 preferably has a length of, for example, 2 cm or more, 10 cm or more, and further 15 cm or more. If it is less than 2 cm, a region where the application width of the material of the photoelectric conversion layer 22 is shifted is formed in the first region 1a. Moreover, it is preferable that the 3rd partition part 33 does not extend in the downstream at the time of apply | coating the material of the photoelectric converting layer 22, ie, the end point side of application | coating. Thereby, since the area of the area | region which overlaps with the sealing part 4 in the partition part 3 can be suppressed to the minimum, the fall of the adhesive strength of the board | substrate 1 and the sealing part 4 can be suppressed.

  As the partition part 3, photocuring resin, such as a photosensitive polyimide material, a silicon oxide, etc. can be used, for example. For example, the partition wall 3 can be formed by applying the above-described material by a coating method or the like and then etching a part of the coating layer. When using a photocurable resin, the partition part 3 can be formed, for example using a photolithographic technique. Moreover, you may form the partition part 3 using sputtering method, a vapor deposition method, CVD (Chemical Vapor Deposition: CVD) method etc. FIG.

  Next, as shown in FIG. 7, the photoelectric conversion layer 22 is formed on the substrate 1 from the third region 1 c toward the first region 1 a along the first partition portion 31 to the third partition portion 33. This material is applied to form the photoelectric conversion layer 22. For example, first, the material of the buffer layer 22a is applied to form the buffer layer 22a. Next, the material of the photoactive layer 22b is applied to form the photoactive layer 22b. Next, the material of the buffer layer 22c is applied to form the buffer layer 22c. Thus, the photoelectric conversion layer 22 can be formed.

  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. . As typical products of the polythiophene-based polymer, for example, CleviosPH500, CleviosPH, CleviosPVPAl4083, CleviosHIL1.1, etc., from Starck are listed. In addition, an inorganic material such as molybdenum oxide may be used for the hole transport layer.

  The hole transport layer is formed using a coating method such as a spin coating method. For example, after forming a coating layer having a desired thickness made of a material applicable to the hole transport layer by spin coating, the hole transport layer can be formed by heating and drying with a hot plate or the like. For example, it is preferable to heat and dry at 140 to 200 ° C. for several minutes to 10 minutes. Further, it is desirable to use a solution to be applied that has been filtered with a filter in advance.

  As the electron transport layer, for example, a metal oxide can be used. Examples of the metal oxide include amorphous titanium oxide obtained by hydrolyzing titanium alkoxide using a sol-gel method. The electron transport layer is formed using a coating method such as a spin coating method.

  When titanium oxide is used as the material for the electron transport layer, the thickness is preferably 5 nm or more and 20 nm or less. When the thickness is less than 5 nm, the hole blocking effect is reduced, so that the generated exciton is deactivated before being dissociated into electrons and holes, and current cannot be efficiently extracted. When the thickness exceeds 20 nm, the resistance increases and the generated current is limited, so that the photoelectric conversion efficiency may decrease. It is desirable to use a coating solution that has been filtered with a filter in advance. After applying to a specified film thickness, it is heated and dried using a hot plate or the like. Heat drying while promoting hydrolysis in air at a temperature of 50 ° C. to 100 ° C. for a time of 2 minutes to 10 minutes. Further, as the electron transport layer, metallic calcium or the like may be used.

  As the photoactive layer 22b, 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 device, the mixed p-type semiconductor and n-type semiconductor form a pn junction having a nano-order size in the photoactive layer 22b, and utilizing photoelectric charge separation generated 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. A derivative such as -thienyl-2 ', 1', 3'-benzothiadiazole)]) may be used, and the photoelectric conversion efficiency can be increased by using the above derivative.

  These conductive polymers are formed by applying a solution dissolved in a solvent. Therefore, a low-cost and large-area photoelectric conversion device can be manufactured using inexpensive equipment.

  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 use in a photoelectric conversion device.

  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 p-type semiconductor is a P3AT system. When the p-type semiconductor is a PCDTBT system, it is preferably about 4: 1.

  In order to apply an organic semiconductor, it is necessary to dissolve in a 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.

  Examples of the method for applying the material of the photoelectric conversion layer 13 include spin coating, dip coating, casting, bar coating, roll coating, wire bar coating, spraying, screen printing, gravure printing, flexographic printing. Method, offset printing method, gravure / offset printing, dispenser coating, nozzle coating method, capillary coating method, ink jet method and the like, and these coating methods can be used alone or in combination.

  FIG. 8 is a schematic view when the photoelectric conversion layer 22 is formed by a coating method using a coating apparatus. FIG. 8 shows the material discharge head 60, the substrate 1, and the partition 3. The material discharge head 60 is provided, for example, in a coating apparatus. The material discharge head 60 has a slit 61 through which a coating material is supplied. The material discharge head 60 is also referred to as an applicator. A die coater or the like can be used as the coating apparatus. At this time, the material discharge head 60 is also referred to as a die head, and the slit 61 is also referred to as a die slit.

  When applying the material of the photoelectric conversion layer 22 using the material discharge head 60, the material of the photoelectric conversion layer 22 is supplied between the material discharge head 60 and the substrate 1 through the slit 61, and the photoelectric conversion layer 22 is supplied. A liquid pool region 70 made of the above material is formed. The liquid reservoir region 70 has a curved surface, a so-called meniscus side surface 71. At this time, the width of the liquid pool region 70 in the application direction of the photoelectric conversion layer 22 is preferably wider than the width of the gap portion 320 in the extending direction of the partition wall portion 3.

  The period of the gap 320 in the extending direction of the partition wall 3 is preferably 1 mm or more and 2 mm or less, and the width of the liquid pool region 70 in the application direction of the photoelectric conversion layer 22 is preferably 2 mm or more and 4 mm or less. . Further, by setting the number of the gaps 320 overlapping the liquid pool region 70 having the above width to, for example, 1 or more and 2 or less, the deviation of the coating width can be suppressed.

  Thereafter, the photoelectric conversion layer 22 is formed by applying the material of the photoelectric conversion layer 22 while moving at least one of the material discharge head 60 and the substrate 1 along the application direction.

  Next, as illustrated in FIG. 9, the electrode 23 is formed so as to be in contact with the upper surface of the photoelectric conversion layer 22 and overlap the electrode 21 with the photoelectric conversion layer 22 interposed therebetween.

  As the electrode 23, for example, a metal or a metal oxide applicable to the electrode 21 can be used. When light is incident through the substrate 5, the electrode 23 has translucency. When the electrode 23 is in contact with the electron transport layer, it is preferable to use a material having a low work function as the electrode 23. Examples of the material having a low work function include alkali metals and alkaline earth metals. Specific examples include Li, In, Al, Ca, Mg, Sm, Tb, Yb, Zr, Na, K, Rb, Cs, Ba, and alloys thereof.

  The electrode 23 may be a single layer or a stack of a plurality of layers made of materials having different work functions. Alternatively, an alloy of one or more materials having a low work function with gold, silver, platinum, copper, manganese, titanium, cobalt, nickel, tungsten, tin, or the like may be used. Examples of the alloy include a lithium-aluminum alloy, a lithium-magnesium alloy, a lithium-indium alloy, a magnesium-silver alloy, a magnesium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, and a calcium-aluminum alloy.

  The thickness of the electrode 23 is, for example, 1 nm or more and 500 nm or less, preferably 10 nm or more and 300 nm or less. If it is thinner than 1 nm, the electrical resistance becomes high, and the generated charges are difficult to take out. If it is thicker than 500 nm, it takes a long time to form the electrode 23, so that the material temperature rises, damages the photoelectric conversion layer 22, and the performance deteriorates. Furthermore, since a large amount of material is used, the time required to occupy the film forming apparatus becomes longer, leading to an increase in cost.

  The electrode 23 is formed by depositing the conductive material by, for example, a vacuum deposition method, a sputtering method, an ion plating method, a plating method, a coating method, or the like. Alternatively, the electrode 23 may be formed using a coating method applicable to the photoelectric conversion layer 22.

  Next, as shown in FIG. 10, the sealing portion 4 is formed so that the element portion 2 is sealed and the gap portion 320 is in contact with the substrate 1.

  As the sealing part 4, for example, glass frit, thermosetting resin, photocurable resin, or the like can be used. Further, by forming the sealing portion 4 while filling the gap portion 320 with resin or the like, the substrate 1 and the sealing portion 4 can be fixed in the gap portion 320. By providing the sealing portion 4, it is possible to suppress contact between the oxygen and moisture as impurities and the photoelectric conversion layer 22.

  When the partition wall portion 3 is formed without providing the gap portion 320, the sealing portion 4 is easily peeled off from the substrate 1. This is because the adhesive strength between the partition wall portion 3 and the sealing portion 4 is lower than the adhesive strength between the substrate 1 and the sealing portion 4. For example, when stress is applied to the photoelectric conversion device, the sealing portion 4 is easily peeled off from the substrate 1 with the partition wall 3 interposed therebetween. For this reason, the adhesive strength between the board | substrate 1 and the sealing part 4 can be raised by providing the space | gap part 320 in the partition part 3. FIG. Moreover, for the same reason, the adhesive strength between the substrate 1 and the sealing portion 4 can be further increased by not extending the partition wall portion 3 on the downstream side when the photoelectric conversion layer is applied.

  Next, as shown in FIG. 11, a substrate 5 is bonded onto the sealing portion 4 so as to cover the element portion 2. At this time, it is preferable that at least the overlapping portion of the first electrode 21, the photoelectric conversion layer 22, and the second electrode is sealed. As the substrate 5, for example, a material applicable to the substrate 1 can be used. In addition, when making light enter through the board | substrate 5, it is preferable that the board | substrate 5 has translucency.

  As shown in FIG. 12, after sealing the element part 2, the substrate 1 is included so as to include a part of the photoelectric conversion layer 22 and a part of the third partition wall part 33 located outside the sealing part 4. You may cut a part of. Thereby, the size of the photoelectric conversion device can be reduced.

  As described above, in the method for manufacturing a photoelectric conversion device according to this embodiment, at least one end of the photoelectric conversion layer is applied by forming a partition wall portion extending from the photoelectric conversion region to the peripheral region. Provided in the peripheral area. Then, since the application | coating width | variety is controlled by apply | coating the material of a photoelectric converting layer along the partition part containing a run-up part from a peripheral region, the space | interval between photoelectric conversion cells can be narrowed.

  The example of the manufacturing method of the photoelectric conversion device of this embodiment is not limited to the example of the manufacturing method described with reference to FIGS. 13 and 14 are schematic plan views illustrating an example of a method for manufacturing a photoelectric conversion device. The above description can be used as appropriate for portions common to the manufacturing method example described with reference to FIGS.

  Similar to the above process, after forming up to the electrode 23, as shown in FIG. 13, a part of the photoelectric conversion layer 22 is removed along at least a part of the second partition wall 32, and a part of the substrate 1 is exposed. By doing so, the gap 220 is formed in a part of the photoelectric conversion layer 22. For example, the gap 220 can be formed by drying the material of the photoelectric conversion layer 22 after application and mechanically peeling it off, or peeling it off with an adhesive tape or the like.

  Thereafter, as shown in FIG. 14, the sealing portion 4 is formed so as to be in contact with the substrate 1 in the gap portion 220. Thereafter, the substrate 5 is bonded to the sealing portion 4 in the same manner as the above process. Since the contact area between the substrate 1 and the sealing portion 4 can be increased by the above process, the adhesive strength between the substrate 1 and the sealing portion 4 can be increased.

(Second Embodiment)
FIG. 15 is a schematic diagram illustrating an example of a photoelectric conversion panel 1 m wide by 1.2 m long. The photoelectric conversion panel shown in FIG. 15 includes a total of twelve photoelectric conversion modules 100 of 4 × 3 × 20-30 cm square. The photoelectric conversion module 100 includes a plurality of photoelectric conversion devices according to the first embodiment. The plurality of photoelectric conversion modules may be electrically connected to each other in series connection or parallel connection.

  As illustrated in FIG. 15, the photoelectric conversion module can be configured using the photoelectric conversion device according to the first embodiment, and the photoelectric conversion panel can be configured using a plurality of photoelectric conversion modules. Since the photoelectric conversion module and the photoelectric conversion panel have high photoelectric conversion efficiency per unit area, for example, they are also suitable as solar cell panels for automobiles and houses, for example.

  As an example, a photoelectric conversion module provided with a partition part having the first partition part, the second partition part, and the third partition part in the above embodiment, and a photoelectric conversion without a partition part as a comparative example Each module was produced. In the photoelectric conversion module of the example, photosensitive polyimide is used as the material of the partition wall, the width in the direction perpendicular to the extending direction of the partition wall is set to 40 μm or more and 400 μm or less, and the width of the gap in the extending direction of the partition wall is set. The thickness of the partition wall was 1 μm, and the length of the third partition wall was 3 cm. In addition, an electron transport layer made of a metal oxide, a photoactive layer in which a polythiophene P-type material and a fullerene derivative are mixed, and a hole transport layer made of a polythiophene polymer material are formed in this order, and thereby a thickness of 0. A 2 μm photoelectric conversion layer was formed.

  In the photoelectric conversion module of the comparative example not provided with the partition wall, the interval between the photoelectric conversion cells could be narrowed only up to 4 mm, and the aperture ratio was as low as 72%. On the other hand, in the photoelectric conversion module of an Example provided with a partition part, the space | interval of a photoelectric conversion cell could be narrowed to 1.2 mm, and the aperture ratio could be made to 91%. From this, it can be seen that by providing the partition wall, the photoelectric conversion cells are integrated, the area of the photoelectric conversion region is increased, and the aperture ratio can be increased.

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 1a ... 1st area | region, 1b ... 2nd area | region, 1c ... 3rd area | region, 2 ... Element part, 21 ... Electrode, 22 ... Photoelectric conversion layer, 220 ... Air gap part, 22a ... Buffer layer, 22b ... photoactive layer, 22c ... buffer layer, 23 ... electrode, 3 ... partition wall part, 3a ... partition wall part, 3b ... partition wall part, 31 ... first partition part, 32 ... second partition part, 320 ... gap part 33 ... 3rd partition part, 4 ... Sealing part, 5 ... Substrate, 60 ... Material discharge head, 61 ... Slit, 70 ... Liquid accumulation area, 71 ... Side surface, 100 ... Photoelectric conversion module.

Claims (15)

A substrate having a first region and a second region surrounding the first region;
A first electrode provided on the first region, a photoelectric conversion layer provided in contact with an upper surface of the first electrode, an upper surface of the photoelectric conversion layer, and the photoelectric conversion layer A second electrode provided so as to overlap with the first electrode with a sandwich,
A first partition wall provided on the first region so as to be in contact with a side surface of the photoelectric conversion layer; the second partition region extending from the first partition wall portion to the second region; A partition part having a second partition part including a void part on the top,
And a sealing portion provided so as to seal the element portion and in contact with the second region in the gap portion. The substrate further includes a third region outside the second region,
The photoelectric conversion device according to claim 1, wherein the partition wall further includes a third partition wall extending from the second partition wall to the third region.   The photoelectric conversion device according to claim 2, wherein the partition wall has one end provided in the third region and the other end provided in the first region or the second region. The photoelectric conversion device according to claim 2, wherein the third partition wall portion has a length of 2 cm or more. The extending direction of the partition wall is a direction parallel to the application direction of the photoelectric conversion layer,
The photoelectric conversion layer extends to said third region, the photoelectric conversion device according to any one of claims 2 to 4.   The photoelectric conversion device according to claim 1, wherein the partition wall portion has an insulating property.   7. The photoelectric conversion device according to claim 1, wherein a height of an upper surface of the partition wall is equal to or higher than a height of an upper surface of the photoelectric conversion layer. The element unit includes a plurality of photoelectric conversion cells including the first electrode, the photoelectric conversion layer, and the second electrode,
The photoelectric conversion device according to any one of claims 1 to 7, wherein an interval between the plurality of photoelectric conversion cells is less than 4.0 mm.   The photoelectric conversion device according to any one of claims 1 to 8, wherein the aperture ratio is 75% or more.   A photoelectric conversion module comprising the photoelectric conversion device according to any one of claims 1 to 9.   A photoelectric conversion panel comprising the photoelectric conversion module according to claim 10. Forming a first electrode on the first region of the substrate having a first region, a second region surrounding the first region, and a third region provided outside the second region; And
A first partition provided on the first region; a second partition that extends from the first partition to the second region and includes a gap in the second region; Forming a partition part having a third partition part extending from the second partition part to the third region,
The photoelectric conversion layer is formed by applying a material of a photoelectric conversion layer on the substrate from the third partition wall portion to the first partition wall portion along the first partition wall portion to the third partition wall portion. And
Forming a second electrode in contact with the upper surface of the photoelectric conversion layer and overlapping the first electrode with the photoelectric conversion layer interposed therebetween;
A method for manufacturing a photoelectric conversion device, comprising: sealing an element portion having the first electrode, the photoelectric conversion layer, and the second electrode; and forming a sealing portion so as to be in contact with the substrate in the gap.   The part of the substrate is cut so as to include a part of the photoelectric conversion layer and a part of the third partition wall located outside the sealing part after sealing the element part. The manufacturing method of the photoelectric conversion apparatus of 12. The second partition wall portion includes a first gap composed of the gap,
After forming the photoelectric conversion layer, a part of the photoelectric conversion layer is removed by removing a part of the photoelectric conversion layer along a part of the second partition wall and exposing a part of the substrate. 14. The method for manufacturing a photoelectric conversion device according to claim 12, wherein a second gap is formed in the first gap and the sealing portion is formed so as to be in contact with the substrate in the second gap. A material for the photoelectric conversion layer is supplied between the material discharge head of the coating apparatus and the substrate to form a liquid pool region made of the material, and at least one of the material discharge head and the substrate is placed in the coating direction. By forming the photoelectric conversion layer by applying the material while moving along,
The method for manufacturing a photoelectric conversion device according to claim 12, wherein a width of the liquid pool region in the application direction is wider than a width of the gap in an extending direction of the partition wall.

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