JP2016100357A - Photoelectric conversion device - Google Patents

Abstract

A photoelectric conversion device having high sealing performance is provided.
A photoelectric conversion device according to an embodiment includes a first electrode provided on a substrate, a first buffer layer, a photoelectric conversion layer, and a second buffer provided on a first region of the first electrode. A stacked structure in which the layers are stacked in this order; a first portion provided on an upper surface of the second buffer layer of the stacked structure; and a first portion provided on at least one side surface of the stacked structure and connected to the first portion. A second electrode having two portions, a first wiring provided on a second region different from the first region of the first electrode, and a second wiring provided on the second portion of the second electrode And a sealing member that covers the photoelectric conversion element and seals the photoelectric conversion element, and is provided with a notch portion that exposes the first and second wirings. And a sealing member.
[Selection] Figure 2

Description

  Embodiments described herein relate generally to a photoelectric conversion device.

  When the material for the photoelectric conversion layer can be produced by coating or printing, there is a possibility that a device can be produced at a lower cost than in the past. Research and development have been actively conducted on solar cells, sensors, and the like using organic photoelectric conversion layer materials or organic and inorganic photoelectric conversion layer materials.

  These photoelectric conversion elements are known to deteriorate when exposed to sunlight unless they are sealed to block oxygen and water. In order to perform complete sealing, it can be realized by forming a strong structure, but the non-photoelectric conversion element portion becomes large and large. High sealing performance is required with the minimum necessary structure.

Japanese Patent No. 4559065

  The present embodiment provides a photoelectric conversion device having high sealing performance.

  The photoelectric conversion device according to the present embodiment is provided on the first electrode provided on the substrate and the first region of the first electrode, and the first buffer layer, the photoelectric conversion layer, and the second buffer layer are arranged in this order. And a first portion provided on an upper surface of the second buffer layer of the stacked structure and a second portion provided on at least one side surface of the stacked structure and connected to the first portion. A second electrode; a first wiring provided on a second region different from the first region of the first electrode; and a second wiring provided on the second portion of the second electrode. A sealing member that covers the photoelectric conversion element and seals the photoelectric conversion element, the sealing member having a notch provided so that the first and second wirings are exposed And a member.

FIG. 1A to FIG. 1C are diagrams showing a photoelectric conversion element according to the first embodiment. FIGS. 2A to 2C are diagrams illustrating the photoelectric conversion device according to the first embodiment. FIGS. 3A to 3C are diagrams showing a photoelectric conversion device according to the second embodiment. 4A to 4C are diagrams showing a photoelectric conversion device according to a third embodiment. FIGS. 5A to 5C are views showing a photoelectric conversion device according to the fourth embodiment. 6A to 6C are diagrams showing a photoelectric conversion apparatus according to the fifth embodiment. The figure which shows the moisture-proof test result of the photoelectric conversion apparatus by an Example. 8A to 8C illustrate a photoelectric conversion device according to a comparative example. The figure which shows the moisture resistance test result of the photoelectric conversion apparatus by a comparative example.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
The photoelectric conversion device according to the first embodiment includes a photoelectric conversion element and has a structure in which the photoelectric conversion element is sealed. This photoelectric conversion element is shown in FIGS. 1 (a) to 1 (c). 1A is a top view of the photoelectric conversion element 1 according to the first embodiment, FIG. 1B is a cross-sectional view taken along the section AA shown in FIG. 1A, and FIG. It is sectional drawing cut | disconnected by cut surface BB shown to 1 (a).

  In the photoelectric conversion element 1 according to the first embodiment, a first electrode 11, a first buffer layer 12, a photoelectric conversion layer 13, a second buffer layer 14, and a second electrode 15 are stacked in this order on a substrate 10. It has a laminated structure. As can be seen from FIG. 1C, the first buffer layer 12 includes a first portion provided on the first electrode 11 and a first portion provided on one side of the first electrode and connected to the first portion. 2 parts. One of the first electrode 11 and the second electrode 15 serves as an anode, and the other serves as a cathode. The photoelectric conversion layer 13 is excited by light incident from the substrate 10 through the first electrode 11 and the first buffer layer 12 or light incident from the second electrode 15 through the second buffer layer 14. The photoelectric conversion layer 13 generates holes and electrons by this excitation. Electrons are attracted to one of the first electrode 11 and the second electrode 15, and holes are attracted to the other.

The first buffer layer 12 and the second buffer layer 14 are respectively sandwiched between the photoelectric conversion layer 13 and the first electrode and between the photoelectric conversion layer 13 and the second electrode 15. Furthermore, a laminated structure including the first buffer layer 12, the photoelectric conversion layer 13, and the second buffer layer 14 is formed on the first region on the upper surface of the first electrode 11. The first electrode 11 is exposed in a second region different from the first region. The second electrode 15 is provided on the second buffer layer 14, and is provided on one side of the laminated structure including the second buffer saw layer 14, the photoelectric conversion layer 13, and the first buffer layer 12. The second electrode 15, first part 15 ₁ and provided on the upper surface of the second buffer layer 14, provided on the second buffer layer 14 and the photoelectric conversion layer 13 and on one side of the first buffer layer 12 second It has a portion 15 _2. The second portion 15 ₂ is connected to the first portion 15 ₁ of the second electrode 15 as well as extending vertically downward to the substrate 10. Both sides of the second portion 15 _2, the substrate 10 is exposed. The first portion 15 ₁ of the second electrode 15, in FIGS. 1 (a) to 1 (c), but completely covers the upper surface of the second buffer layer 14, the upper surface of the second buffer layer 14 one You may provide so that a part may be exposed. That is, the size of the first portion 15 ₁ of the plane of the second electrode 15 may be smaller than the size of the upper surface of the second buffer layer 14.

  Hereinafter, constituent members of the photoelectric conversion element according to this embodiment will be described.

(Substrate 10)
The substrate 10 is for supporting other constituent members. The substrate 10 is preferably one that can form electrodes and is not altered by heat or an organic solvent. Examples of the material of the substrate 10 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 the like. Examples include plastics, polymer films, stainless steel (SUS), and silicon substrates. In the case where stainless steel (SUS) metal material or the like is used as the substrate 10, between the second portion 15 ₂ and the substrate 10 of the second electrode 15 insulating film (not shown) is provided.

  The substrate 10 is transparent when it is disposed on the light incident side. If the electrode opposite the substrate is transparent or translucent, an opaque substrate may be used. The thickness of the substrate is not particularly limited as long as it has sufficient strength to support other components. When the substrate 10 is disposed on the light incident side, for example, a moth-eye structure antireflection film is provided on the light incident surface to efficiently capture light and improve the energy conversion efficiency of the cell. Is possible. The moth-eye structure has a structure with a regular protrusion arrangement of about 100 nm on the surface, and the refractive index in the thickness direction changes continuously by this protrusion structure. Since there is no continuous change surface, reflection of light is reduced and cell efficiency is improved.

(First electrode 11 and second electrode 15)
The first electrode 11 and the second electrode 15 are not particularly limited as long as they have conductivity. A transparent or translucent conductive material is used for the electrode through which light is transmitted. Both electrodes are formed by vacuum deposition, sputtering, ion plating, plating, coating, or the like. Examples of the transparent or translucent electrode material include a conductive metal oxide film and a translucent metal thin film. Specifically, indium oxide, zinc oxide, tin oxide, and their composites, ITO (Indium Tin Oxide), fluorine-doped tin oxide (FTO), or indium, zinc, and oxide Or the like, a tin oxide film manufactured using a conductive glass made of or the like is used. In particular, ITO or FTO is preferable. Moreover, you may use metals, such as gold | metal | money, platinum, silver, copper.

  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. In the case of ITO, the film thickness is preferably 30 nm to 300 nm. If it is thinner than 30 nm, the conductivity is lowered, the resistance is increased, and the photoelectric conversion efficiency is lowered. If it is thicker than 300 nm, the ITO becomes inflexible and cracks when stress acts on the ITO. The sheet resistance is preferably as low as possible, and is preferably 10Ω / □ or less. It may be a single layer or may be a stack of layers made of materials having different work functions.

  In addition, when forming in contact with the electron carrying layer mentioned later, it is preferable to use a material with a low work function. Examples of the material having a low work function include alkali metals and alkaline earth metals. Specifically, a simple substance including at least one element selected from the group consisting of Li, In, Al, Ca, Mg, Sm, Tb, Yb, Zr, Na, K, Rb, Cs, and Ba, and selection And alloys containing at least one element made. The electrode may be a single layer or may be a laminate of layers made of materials having different work functions. Moreover, an alloy of at least one of the materials having a low work function and 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 calcium-indium alloy, a magnesium-aluminum alloy, an indium-silver alloy, and a calcium-aluminum alloy. The film thickness is 1 nm to 500 nm, preferably 10 nm to 300 nm. When the film thickness is thinner than the above range, the resistance becomes too large and the generated charge cannot be sufficiently transmitted to the external circuit. When the film thickness is thick, it takes a long time to form the electrode, so that the material temperature rises, damages other materials, and the performance deteriorates. Further, since a large amount of material is used, the occupation time of the film forming apparatus becomes longer, leading to an increase in cost.

  In the case of forming in contact with a hole transport layer described later, it is preferable to use a material having a high work function. Examples of the material having a high work function include at least one element selected from the group consisting of Au, Ag, and Cu, and an alloy containing at least one selected element. It may be a single layer or may be a stack of layers made of materials having different work functions. The film thickness is 1 nm to 500 nm, preferably 10 nm to 300 nm. When the film thickness is thinner than the above range, the resistance becomes too large and the generated charge cannot be sufficiently transmitted to the external circuit. When the film thickness is thick, it takes a long time to form the electrode, so that the material temperature rises, damages other materials, and the performance deteriorates. Further, since a large amount of material is used, the occupation time of the film forming apparatus becomes long, leading to an increase in cost.

(First buffer layer 12 and second buffer layer 14)
One of the first buffer layer 12 and the second buffer layer 14 serves as a hole transport layer, and the other serves as an electron transport layer. The material of the second buffer layer 14 is preferably a halogen compound or a metal oxide. The thickness of the first buffer layer 12 sandwiched between the first electrode 11 and the photoelectric conversion layer 13 is preferably thicker than the second buffer layer sandwiched between the second electrode and the photoelectric conversion layer 13. .

  Suitable examples of the halogen compound include LiF, LiCl, LiBr, LiI, NaF, NaCl, NaBr, NaI, KF, KCl, KBr, KI, and CsF. More preferably, LiF is mentioned. Preferable examples of the metal oxide include titanium oxide, molybdenum oxide, vanadium oxide, zinc oxide, nickel oxide, lithium oxide, calcium oxide, cesium oxide, and aluminum oxide.

  As a material for 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 may be used. Typical examples of the polythiophene-based polymer include Clevios PH500, Clevios PH, Clevios PVPAl4083 and Clevios HIL1, 1 from Starck, Inc. Molybdenum oxide is a suitable material for inorganic materials. In this case, the film thickness is preferably 20 nm to 100 nm, and if it is too thin, the action of preventing a short circuit of the lower electrode is lost and a short circuit occurs. Since the generated current is limited, the light conversion efficiency decreases, and the film forming method is not particularly limited as long as it can form a thin film, but it can be applied by, for example, spin coating. After coating to a film thickness, it is heat-dried with a hot plate etc. It is preferable to heat-dry for about several minutes to 10 minutes at 140 to 200 ° C. The solution to be applied should be filtered in advance with a filter. desirable.

  The electron transport layer has a function of efficiently transporting electrons. Examples of the material for the electron transport layer include metal oxides such as amorphous titanium oxide obtained by hydrolyzing titanium alkoxide by a sol-gel method. The film forming method is not particularly limited as long as it is a method capable of forming a thin film, and examples thereof include a spin coating method. When titanium oxide is used as the material for the electron transport layer, the film thickness is desirably 5 nm to 20 nm. When the film thickness is thinner than the above range, the hole blocking effect is reduced, so that the generated excitons are deactivated before dissociating into electrons and holes, and current cannot be efficiently extracted. When the film thickness is too thick, the film resistance increases and the generated current is limited, so that the light conversion efficiency is lowered. 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 at 50 to 100 ° C. for several minutes to 10 minutes while promoting hydrolysis in the air. For inorganic materials, metallic calcium and the like are suitable materials.

(Photoelectric conversion layer)
As the photoelectric conversion layer, a heterojunction photoelectric conversion layer or a bulk heterojunction photoelectric conversion layer made of an organic semiconductor can be used. The parc heterojunction photoelectric conversion layer is characterized in that a p-type semiconductor and an n-type semiconductor are mixed in the photoelectric conversion layer to form a micro layer separation structure. The mixed p-type semiconductor and n-type semiconductor form a pn junction having a nano-order size in the photoelectric conversion layer, and a current is obtained by utilizing photocharge separation generated at the junction surface. A p-type semiconductor is composed of a material having an electron donating property. On the other hand, the n-type semiconductor is made of a material having an electron accepting property. In the embodiment of the present invention, at least one of the p-type semiconductor and the n-type semiconductor may be an organic semiconductor.

  Examples of p-type organic 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. Polysiloxane derivatives having aromatic amines in the side chain or main chain, polyaniline and derivatives thereof, phthalocyanine derivatives, porphyrins and derivatives thereof, polyphenylene vinylene and derivatives thereof, polythienylene vinylene and derivatives thereof, and the like can be used, These may be used in combination. These copolymers may be used, and examples thereof include a thiophene-fluorene copolymer, a phenylene ethynylene-phenylene vinylene copolymer, and the like.

  A preferred p-type organic semiconductor is polythiophene which is a conductive polymer having π conjugation and derivatives thereof. 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.

  In recent years, PCDTBT (poly [N-9 "-hepta-decanyl-2,7-carbazole-alt-5,5- (4 ', 7'-di ()), which is a copolymer of carbazole, benzothiadiazole and thiophene. Derivatives such as -2-thienyl-2 ′, 1 ′, 3′-benzothiadiazole)]) are known as compounds capable of obtaining excellent photoelectric conversion efficiency.

  These conductive polymers can be formed by applying a solution dissolved in a solvent. Therefore, there is an advantage that a large-area organic thin film solar cell can be manufactured at low cost with inexpensive equipment by a printing method or the like.

As the n-type organic semiconductor, fullerene and derivatives thereof are preferably used. The fullerene derivative used here is not particularly limited as long as it is a derivative having a fullerene skeleton. Specific examples include derivatives composed of C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C _{84 and the} like as a basic skeleton. 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 C ₆₀ H ₃₆ and C ₇₀ H ₃₆ , oxide fullerenes such as C ₆₀ and C ₇₀ , fullerene metal complexes, and the like.

Among the above, it is particularly preferable to use 60PCBM ([6,6] -phenyl C ₆₁ butyric acid methyl ester) or [70] PCBM ([6,6] -phenyl C ₇₁ butyric acid methyl ester) as the fullerene derivative.

When using the unmodified fullerene, it is preferred to use a C _70. Fullerene C ₇₀ is the generation efficiency of photocarriers high, are suitable for use in organic thin film solar cell.

  The mixing ratio of the n-type organic semiconductor and the p-type organic semiconductor in the photoelectric conversion layer is preferably about n: p = 1: 1 when the p-type semiconductor is a P3AT system. When the p-type semiconductor is a PCDTBT system, it is preferable that n: p = 4: 1.

  In order to apply an organic semiconductor, it is necessary to dissolve in a solvent. Examples of the solvent used therefor include toluene, xylene, tetralin, decalin, mesitylene, n-butylbenzene, sec-butylbenzene, and tert-butylbenzene. Unsaturated hydrocarbon solvents such as, halogenated aromatic hydrocarbon solvents such as chlorobenzene, dichlorobenzene, and trichlorobenzene, carbon tetrachloride, chloroform, dichloromethane, dichloroethane, chlorobutane, bromobutane, chloropentane, chlorohexane, bromohexane, Halogenated saturated hydrocarbon solvents such as chlorocyclohexane and ethers such as tetrahydrofuran and tetrahydropyran. In particular, a halogen-based aromatic solvent is preferable. These solvents can be used alone or in combination.

  As a method of applying a solution to form a film, spin coating, dip coating, casting, bar coating, roll coating, wire bar coating, spraying, screen printing, gravure printing, flexographic printing, offset Examples thereof include a printing method, gravure / offset printing, dispenser coating, nozzle coating method, capillary coating method, and ink jet method, and these coating methods can be used alone or in combination.

Perovskite can be used for the photoelectric conversion layer. Perovskite can be expressed by ABX ₃ consisting of ions A, B, and X. When the ion B is smaller than the ion A, a perovskite structure may be taken. It has a cubic unit cell, and A is arranged at each vertex of the cubic crystal, B is arranged at the body center, and X is arranged at each face center of the cubic crystal around this. The orientation of the BX ₆ octahedron is easily distorted by the interaction with A. Due to the decrease in symmetry, the Mott transition occurs and the valence electrons localized in the ions M can spread as a band. The ion A is preferably CH ₃ NH ₃ , the ion B is preferably Pb or Sn, and the ion X is preferably Cl, Br, or I. The materials constituting the ions A, B, and X may be single or mixed.

Next, the photoelectric conversion device of the first embodiment in which the photoelectric conversion element 1 is sealed will be described with reference to FIGS. 2 (a) to 2 (c). FIG. 2A shows the sealing member 20 of the photoelectric conversion element device, and FIG. 2B shows a top view of the photoelectric conversion element 1. Wiring 11a for electrical connection to the outside on a second region of the first electrode 11 is provided, the wiring 15a for electrical connection to the outside on the second portion 15 ₂ of the second electrode 15 Is provided. The wiring 11a and the wiring 15a are provided at substantially the center of the upper part and the lower part when the photoelectric conversion element 1 is viewed from above. FIG. 2C is a top view when the sealing member 20 is bonded to the photoelectric conversion element 1.

As can be seen from FIGS. 2A and 2C, the sealing member 20 is provided with notches 24a and 24b in order to avoid the wirings 11a and 15a, respectively. Exposed. That is, the sealing member 20 has an H shape when viewed from above (FIG. 2A). The sealing member 20 may be provided with a non-adhesive region 22 that does not have a bonding surface with the photoelectric conversion element. More preferably, the non-adhesive region is recessed. In this case, without being housed in the second portion 15 ₂ is engraved 22 of the second electrode 15, a step is formed. However, this step can be absorbed by the adhesive used when sealing.

  The means for bonding the sealing member 20 and the substrate 10 is not particularly limited. For example, an adhesive can be used. As the adhesive, a photocurable epoxy resin or a thermosetting epoxy resin can be used. Further, the resin may contain spacer particles. Thereby, the thickness of the adhesive located between the sealing member 20 and the substrate 10 can be controlled.

  FIG. 2C shows the positional relationship when the sealing member 20 and the substrate 10 are bonded together. The distance d1 from the laminated structure including the photoelectric conversion layer 13 to the end 12 of the sealing member 20 and the distance d2 from the laminated structure including the photoelectric conversion layer 13 to the notch 24 can be known.

  As the sealing member 20, glass, a metal plate, a polymer film, or the like can be used. Glass can be processed into a desired shape by cutting and polishing. Metal plates and polymer films can be engraved by extrusion. The sealing member 20 is, for example, an inorganic material such as alkali-free glass or quartz glass, plastic such as polyethylene, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polyamide, polyamideimide, liquid crystal polymer, or cycloolefin polymer. , Polymer films, stainless steel (SUS), metal substrates such as silicon, and the like. The polymer film may have a laminated structure of a metal film and a metal oxide film. As the metal film, for example, aluminum, as the metal oxide film, for example, titanium oxide, molybdenum oxide, vanadium oxide, zinc oxide, nickel oxide, lithium oxide, calcium oxide, cesium oxide, aluminum oxide, Silicon oxide is a suitable example.

(Second Embodiment)
Next, a photoelectric conversion device according to the second embodiment will be described with reference to FIGS. 3 (a) to 3 (c). The photoelectric conversion device of the second embodiment includes a photoelectric conversion element 1A illustrated in FIG. 3B and a sealing member 20A illustrated in FIG. FIG. 3B is a top view of the photoelectric conversion element 1A. The photoelectric conversion device 1A, in the photoelectric conversion element 1 shown in FIGS. 1 (a) to 1 (c), the second portion 15 ₂ of the second electrode 15 as shown in FIG. 3 (b), to the right side It is extended. Incidentally, a portion extending in the second portion 15 _2, between the first electrode 11 has a gap, as shown in FIG. 3 (b), in the gap is exposed substrate 10.

  FIG. 3A is a top view of the sealing member 20A of the photoelectric conversion device according to the second embodiment. The sealing member 20A is provided with a non-adhesive region 22 on the back surface side of the sealing member 20A in order to accommodate a laminated structure including the first buffer layer 12, the photoelectric conversion layer 13, and the second buffer layer 14. ing. The sealing member 20A is provided with cutouts 24a and 24b on the right sides of the upper and lower portions when viewed from above. As can be seen from FIG. 3B, in the photoelectric conversion element 1A, wirings 11a and 15a for establishing electrical connection between the outside and each of the first electrode 11 and the second electrode 15 are provided in the notches 24a. , 24b so as to match the position. FIG. 3C is a top view when the sealing member 20 </ b> A is bonded onto the photoelectric conversion element 1.

(Third embodiment)
Next, a photoelectric conversion device according to the third embodiment will be described with reference to FIGS. 4 (a) to 4 (c). The photoelectric conversion device of the second embodiment includes a photoelectric conversion element 1A illustrated in FIG. 4B and a sealing member 20B illustrated in FIG. The photoelectric conversion element 1A shown in FIG. 4B is the same as the photoelectric conversion element 1A of the second embodiment.

  FIG. 4A is a top view of the sealing member 20B of the photoelectric conversion device of the third embodiment. The sealing member 20B is provided with a non-adhesive region 22 on the back surface side of the sealing member 20B in order to accommodate the laminated structure including the first buffer layer 12, the photoelectric conversion layer 13, and the second buffer layer 14. ing. The sealing member 20B is provided with notches 24a and 24b at diagonal corners when viewed from above. As can be seen from FIG. 4B, the photoelectric conversion element 1A includes wirings 11a and 15a for establishing electrical connection with the first electrode 11 and the second electrode 15 at the corners on the diagonal line. It is provided so as to match the positions of the notches 24a and 24b. FIG. 4C is a top view when the sealing member 20 </ b> B is bonded onto the photoelectric conversion element 1.

(Fourth embodiment)
Next, a photoelectric conversion device according to the fourth embodiment will be described with reference to FIGS. 5 (a) to 5 (c). The photoelectric conversion device of the fourth embodiment includes a photoelectric conversion element 1B illustrated in FIG. 5B and a sealing member 20C illustrated in FIG. FIG. 5B is a top view of the photoelectric conversion element 1B. The photoelectric conversion element 1B is different from the photoelectric conversion element 1A shown in FIG. 3 (b), the second portion 15 ₂ of the second electrode 15 extends halfway to reach the right-hand side of the substrate 10. Instead, the first electrode 11 is configured to extend along the right side. Incidentally, a portion extending in the second portion 15 _2, between the first electrode 11 has a gap, as shown in FIG. 5 (b), in the gap is exposed substrate 10.

  FIG. 5A is a top view of the sealing member 20C of the photoelectric conversion device according to the fourth embodiment. The sealing member 20C is provided with a non-adhesive region 22 on the back surface side of the sealing member 20C in order to accommodate the laminated structure including the first buffer layer 12, the photoelectric conversion layer 13, and the second buffer layer 14. ing. Further, this sealing member 20C is provided with a notch 24 at the upper right corner when viewed from above. As can be seen from FIG. 5B, in the photoelectric conversion element 1B, wirings 11a and 15a for establishing electrical connection with the first electrode 11 and the second electrode 15 are cut off at the upper right corner. It is provided so as to match the position of the notch 24. FIG. 5C is a top view when the sealing member 20 </ b> C is bonded onto the photoelectric conversion element 1.

(Fifth embodiment)
Next, a photoelectric conversion device according to a fifth embodiment will be described with reference to FIGS. 6 (a) and 6 (b). The photoelectric conversion device of the fifth embodiment includes a photoelectric conversion element 1C illustrated in FIG. 6B and a sealing member 20D illustrated in FIG. FIG. 6B is a plan view of the photoelectric conversion element 1C. This photoelectric conversion element 1C is different from the photoelectric conversion element 1A shown in FIG. 3B in the position of the wiring 11a.

  FIG. 6A is a top view of the sealing member 20D of the photoelectric conversion device of the fifth embodiment. The sealing member 20D is provided with a non-adhesive region 22 on the back surface side of the sealing member 20C in order to accommodate a laminated structure including the first buffer layer 12, the photoelectric conversion layer 13, and the second buffer layer 14. ing. Further, this sealing member 20D is provided with a notch 24 at the upper right corner when viewed from above. FIG. 6C is a top view when the sealing member 20D is bonded onto the photoelectric conversion element 1C. As can be seen from FIG. 6C, the sealing member 20D is smaller than the photoelectric conversion element 1, and a part of the first electrode 11 (a lower part in the drawing) is exposed when viewed from above. The photoelectric conversion element 1 </ b> C is provided with a wiring 11 a for establishing an electrical connection with the outside on the exposed part of the first electrode 11, and the second electrode 15 and the outside at the upper right corner. Wiring 15a for establishing an electrical connection is provided so as to match the position of the notch 24.

  As described above, the shape of the sealing member can be made the same size as the substrate on which the photoelectric conversion element is formed or can be made slightly smaller than the substrate. Preferably, the whole or a part thereof coincides with the outer peripheral portion of the substrate. That is, it is preferable to maximize the adhesion area between the sealing member and the substrate. The effect of extending the time to reach the photoelectric conversion layer can be expected by enlarging the adhesion surface, which is an infiltration route of oxygen and water. Furthermore, the adhesive force between the sealing member and the substrate can be increased by having the end of the sealing member farther than the notch. Thereby, peeling of the sealing member and the substrate during the deterioration process can be prevented and durability can be enhanced.

(Example)
A photoelectric conversion device of this example will be described. This photoelectric conversion device is the photoelectric conversion device of the first embodiment. A glass substrate is used as the substrate 10 of the photoelectric conversion element 1, and ITO is used as the electrode 11. PEDOT-PSS is used as the first buffer layer 12 and serves as a hole transport layer. LiF is used as the second buffer layer 14 and serves as an electron transport layer. In the photoelectric conversion 13, [70] PCBM is used as an n-type organic semiconductor material as a p-type organic semiconductor material, and these PCE-10 (1 Material Company) and [70] PCBM form a bulk heterojunction. Blue plate glass is used as the sealing member.

  Next, a method for manufacturing a photoelectric conversion device will be described.

  First, ITO was formed on the glass substrate 11 by sputtering, and then PEDOT-PSS as a first buffer layer 12 was formed on the first region of ITO by spin coating. Since the light receiving surface at this time is a 1 cm square, the length of the first region of ITO is 1 cm. Subsequently, PEDOT-PSS was dried at 120 ° C. for 10 minutes.

  Next, a solution of PCE-10 and [70] PCBM was spin-coated on the first buffer layer 12 as the photoelectric conversion layer 13. PCE-10 and [70] PCBM were prepared at a weight ratio of 1: 1. CB (chlorobenzene) was used as the solution.

  Next, a LiF film of 0.02 nm is formed on the photoelectric conversion layer 13 by vapor deposition to form the second buffer layer 14. Subsequently, AgMg (Mg: 90 wt%) is deposited to a thickness of 100 nm on the second buffer layer 14 to form the second electrode 15. Here, the thickness of LiF formed is smaller than the atomic diameter of Li of 0.34 nm. For this reason, it is hard to consider it as a continuous film, and means an average film thickness.

  The sealing member 20 shown in FIG. 2A was attached to the substrate 10 of the photoelectric conversion element 1 thus formed. A UV curable resin was used for pasting.

  FIG. 7 shows the results of evaluation in accordance with the B-2 moisture resistance test of the JIS-C8938 amorphous solar cell module environmental test method and durability test method. As can be seen from FIG. 7, when the initial conversion efficiency was 1, 90% could be maintained after 1000 hours.

(Comparative example)
As a photoelectric conversion device of a comparative example, a device in which the sealing member 200 illustrated in FIG. 8A was attached to the photoelectric conversion element 1 described in the first example was manufactured. FIG. 8A shows a top view of the sealing member 200 of the photoelectric conversion device of the comparative example. FIG. 8B is a top view of the photoelectric conversion element 1 described in the first embodiment. FIG. 8C is a top view when the sealing member 200 is attached to the photoelectric conversion element 1.

  FIG. 9 shows the result of evaluating the photoelectric conversion device of this comparative example based on the JIS-C8938 amorphous solar cell module environmental test method and the durability test method B-2. As can be seen from FIG. 9, when the initial conversion efficiency was 1, the best result was maintained at 80% after 1000 hours. In the structure of the comparative example, in order to expose a part of the wiring on the wiring board, it can be seen that the adhesion area becomes small without crispness. As a result, the ingress route of oxygen and water in the atmospheric environment is relatively short, and it is considered that the deterioration has progressed.

  As described above, according to each embodiment and example, it is possible to provide a photoelectric conversion device having a high sealing performance with a minimum necessary structure.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These 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 invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

1, 1A, 1B, 1C Photoelectric conversion element 10 Substrate 11 First electrode 11a Wiring 12 First buffer layer 13 Photoelectric conversion layer 14 Second buffer layer 15 Second electrode 15a Wiring 20 Sealing member 22 Non-adhesive region 24, 24a, 24b Notch

Claims (10)

A laminated structure in which a first electrode provided on a substrate, a first buffer layer, a photoelectric conversion layer, and a second buffer layer provided on a first region of the first electrode and laminated in this order; A first electrode provided on an upper surface of the second buffer layer having a stacked structure; a second electrode having a second part provided on at least one side surface of the stacked structure and connected to the first part; and the first electrode A photoelectric conversion element comprising: a first wiring provided on a second region different from the first region; and a second wiring provided on the second portion of the second electrode;
A sealing member that covers the photoelectric conversion element and seals the photoelectric conversion element, the sealing member having a notch provided to expose the first and second wirings;
A photoelectric conversion device comprising:   The photoelectric conversion device according to claim 1, wherein the notch is provided in an outer peripheral portion of the sealing member.   2. The photoelectric conversion device according to claim 1, wherein the sealing member uses the laminated structure and the first portion of the second electrode as a non-adhesive region.   2. The photoelectric conversion device according to claim 1, wherein the sealing member is provided with a recess for accommodating the laminated structure and the first portion of the second electrode.   The sealing member has a pair of sides facing at least in a planar shape, and the notch includes first and second notches provided in the vicinity of the pair of facing sides of the sealing member. The photoelectric conversion device according to claim 1.   The photoelectric conversion device according to claim 5, wherein the first and second cutouts are provided at a central portion of the set of sides.   The photoelectric conversion device according to claim 5, wherein the first and second cutouts are provided at end portions of the set of sides.   The photoelectric conversion device according to claim 5, wherein the first and second cutouts are provided at one diagonal end of the sealing member.   The photoelectric conversion device according to claim 1, wherein the notch is provided at one corner of the sealing member.   The photoelectric conversion device according to claim 1, wherein the sealing member has a planar shape that is the same as or smaller than the photoelectric conversion element.

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