JP6413208B2 - Manufacturing method of organic solar cell - Google Patents

Description

  The present invention relates to an organic solar cell.

  While organic solar cells are expected to be inexpensive and flexible products based on coating printing technology and roll-to-roll manufacturing processes, they have a problem of poor durability compared to conventional inorganic devices such as silicon. . Specific examples include deterioration due to heat, deterioration due to gas such as moisture and oxygen, and mechanical deterioration due to insufficient strength of the organic film of the device.

  As a method for solving such a problem, for example, Patent Document 1 proposes a method of sealing by bonding a barrier film on an organic solar cell. For example, Patent Document 2 proposes a method of sealing by providing a barrier layer by direct film formation by plasma CVD or sputtering on an organic device.

JP2012-080060A JP 2011-231357 A

In order to obtain the sufficient sealing performance, a thick film member must be used, and flexibility is impaired. The present inventors examined a method for directly forming a barrier layer on an organic solar cell with high productivity. In order to improve the sealing performance of the barrier layer, it is necessary to obtain a dense film quality, while it is necessary to prevent damage to the organic solar cell on which the barrier layer is formed. In order to satisfy these requirements, it is necessary to extremely reduce the film forming rate of the barrier layer. In addition, there is also a problem that the barrier layer thickness must be extremely increased in order to cover the surface roughness and steps inherent to the organic solar cell. However, if it does so, the production rate is lowered and the productivity is deteriorated, making industrial production difficult. Furthermore, when the barrier layer is dense and thick, the organic solar cell is destroyed by the stress, the interface between the barrier layer and the organic solar cell is peeled off, or the barrier layer itself is easily broken by bending deformation. Problems also arise.
Furthermore, it has been found that even when a barrier layer is formed directly on an organic solar cell, the photoelectric conversion performance is significantly reduced by light. Various factors are complicatedly related to the deterioration of organic solar cells with respect to light, and the mechanism has not yet been clarified.

  This invention solves such a problem, and makes it a subject to provide the organic solar cell which was cheap and excellent in durability.

  The present inventors have found that there is a problem inherent to the organic solar cell element when the organic solar cell element is sealed with a barrier layer. That is, to compensate for the low physical film strength when compared with inorganic devices such as silicon, and to avoid the step shape caused by the formation of an organic film such as coating printing on the surface of the organic solar cell element It was found to be important for ensuring the durability of organic solar cells.

Therefore, the present inventors have an organic solar cell element having at least a pair of electrodes on the substrate and an active layer existing between the electrodes, and a barrier layer laminated on the organic solar cell element. In an organic solar cell, it discovered that the said subject could be solved by laminating | stacking an undercoat layer between this organic solar cell element and this barrier layer, and completed this invention. The outline of the present invention is as follows.

  The present invention relates to an organic solar cell having an organic solar cell element having at least a pair of electrodes on a substrate, an active layer existing between the electrodes, and a barrier layer laminated on the organic solar cell element. The organic solar cell is characterized in that an undercoat layer is laminated between the organic solar cell element and the barrier layer.

  It is preferable that an overcoat layer is further laminated on the barrier layer, and it is further preferred that a film-like member is laminated via an adhesive layer.

  Moreover, it is preferable that the thickness of an undercoat layer is 0.1-20 micrometers.

  The elastic modulus at 23 ° C. of the undercoat layer is 20 GPa or less, the elastic modulus at 23 ° C. of the overcoat layer is 100 MPa or more, and the elastic modulus of the undercoat layer is equal to the elastic modulus of the overcoat layer. It is preferably 1/10 or more and 2 or less.

  Further, the material of the undercoat layer includes one or more selected from polyester resins, polyurethane resins, and acrylic resins, and the material of the overcoat layer is one or more selected from polyester resins, epoxy resins, and acrylic resins. It is preferable to contain.

  In addition, the barrier layer is formed by a vacuum film formation method by any one or a combination of vacuum deposition, chemical vapor deposition (CVD), and sputtering, and the undercoat layer and / or the overcoat layer is wet under atmospheric pressure. It is preferably formed by a coating method.

  Moreover, it is preferable that a base material is a resin film. Moreover, it is preferable to use as an organic solar cell module containing an organic solar cell.

  According to the present invention, an organic solar battery that is inexpensive and excellent in durability can be obtained.

  By providing the undercoat layer, the flatness of the surface on which the barrier layer is formed can be improved, high sealing performance can be exhibited even with a thin barrier layer, and the production rate can be improved. Moreover, by using an undercoat layer as the base of the barrier layer, the denseness of the barrier layer can be improved and high sealing performance can be exhibited. Furthermore, by using an undercoat layer, the adhesiveness with the barrier layer is increased, and interface peeling can be suppressed. In addition, due to the moderate modulus of elasticity of the undercoat layer, the undercoat layer acts as a stress relaxation layer between the barrier layer and the organic solar cell, preventing the organic solar cell from being destroyed and improving the durability of the organic solar cell . Also, improvement in flexibility is expected.

It is a conceptual diagram which shows the one aspect | mode of an organic solar cell element. It is the conceptual diagram shown about the one aspect | mode of the organic solar cell of this invention. It is the conceptual diagram shown about the one aspect | mode of the organic solar cell of this invention. It is the conceptual diagram shown about the one aspect | mode of the organic solar cell of this invention. It is a figure which shows typically the structure of the organic thin film solar cell module as one aspect | mode of the organic solar cell of this invention. It is a conceptual diagram which shows the structure of the solar cell panel using an organic solar cell as one aspect | mode of the organic solar cell of this invention.

The present invention will be specifically described below.
The present invention relates to an organic solar cell having an organic solar cell element having at least a pair of electrodes on a substrate, an active layer existing between the electrodes, and a barrier layer laminated on the organic solar cell element. An undercoat layer is laminated between the organic solar cell element and the barrier layer.

<Organic solar cell>
Hereinafter, the organic solar cell of the present invention will be described.
An organic solar cell has an organic solar cell element having at least a pair of electrodes and an active layer existing between the electrodes on a substrate. In the organic solar cell of the present invention, an undercoat layer and a barrier layer are laminated on the surface on which the electrodes and the active layer of the organic solar cell element are laminated.

<1. Organic solar cell element>
The organic solar cell element has at least a pair of electrodes and an active layer existing between the electrodes on a base material. FIG. 1 shows one embodiment of an organic solar cell element. The organic solar cell element shown in FIG. 1 is an organic solar cell element used for a general organic solar cell, but the organic solar cell element according to the present invention is not limited to that shown in FIG. An organic solar cell element 107 according to an embodiment of the present invention includes a base material 106, a cathode 101, an electron extraction layer 102, an active layer 103 (a layer containing a p-type semiconductor compound and an n-type semiconductor material), a hole extraction layer. 104 and the anode 105 have a layered structure formed in order.

[1-1. Buffer layer (102, 104)]
The organic solar cell element 107 has an electron extraction layer 102 between the cathode 101 and the active layer 103. The organic solar cell element 107 has a hole extraction layer 104 between the active layer 103 and the anode 105. In the organic solar cell element according to the present invention, the electron extraction layer 102 and the hole extraction layer 104 are not essential and can be arbitrarily provided.

  The electron extraction layer 102 and the hole extraction layer 104 are preferably disposed so as to sandwich the active layer 103 between the pair of electrodes (101, 105). That is, when the organic solar cell element 107 includes both the electron extraction layer 102 and the hole extraction layer 104, the electrode 105, the hole extraction layer 104, the active layer 103, the electron extraction layer 102, and the electrode 101 are arranged in this order. be able to. When the organic solar cell element 107 includes the electron extraction layer 102 and does not include the hole extraction layer 104, the electrode 105, the active layer 103, the electron extraction layer 102, and the electrode 101 can be arranged in this order. The stacking order of the electron extraction layer 102 and the hole extraction layer 104 may be reversed, or at least one of the electron extraction layer 102 and the hole extraction layer 104 may be composed of a plurality of different layers.

[1-1-1. Electron extraction layer (102)]
The material of the electron extraction layer 102 is not particularly limited as long as it is a material that improves the efficiency of extracting electrons from the active layer 103 to the electrode 101, and examples thereof include inorganic compounds and organic compounds.

Examples of the material of the inorganic compound include salts of alkali metals such as Li, Na, K or Cs; n-type semiconductor oxides such as titanium oxide (TiOx) and zinc oxide (ZnO). Among them, the alkali metal salt is preferably a fluoride salt such as LiF, NaF, KF or CsF, and the n-type semiconductor oxide is preferably zinc oxide (ZnO). The operation mechanism of such a material is unknown, but when combined with the cathode 101 made of Al or the like, the work function of the cathode 101 can be reduced and the voltage applied to the inside of the organic solar cell element can be increased. Conceivable.

  Examples of organic compound materials include, for example, phosphine compounds having a double bond between a phosphorus atom and a group 16 element such as triarylphosphine oxide compounds; bathocuproin (BCP) or bathophenanthrene (Bphen), A phenanthrene compound which may have a substituent and may be substituted at the 1-position and the 10-position with a heteroatom; a boron compound such as triarylboron; and (8-hydroxyquinolinato) aluminum (Alq3) Organometallic oxide; Compound having 1 or 2 ring structure which may have a substituent such as oxadiazole compound or benzimidazole compound; Naphthalenetetracarboxylic anhydride (NTCDA) or perylenetetracarboxylic acid Of dicarboxylic anhydrides, such as anhydrides (PTCDA) Aromatic compounds having Unachijimigo dicarboxylic acid structure.

  The LUMO energy level of the material of the electron extraction layer 102 is not particularly limited, but is usually −4.0 eV or more, preferably −3.9 eV or more. On the other hand, it is usually −1.9 eV or less, preferably −2.0 eV or less. It is preferable that the LUMO energy level of the material of the electron extraction layer 102 is −1.9 eV or less because charge transfer can be promoted. It is preferable that the LUMO energy level of the material of the electron extraction layer 102 is −4.0 eV or more because reverse electron transfer to the n-type semiconductor material can be prevented.

  The HOMO energy level of the material of the electron extraction layer 102 is not particularly limited, but is usually −9.0 eV or more, preferably −8.0 eV or more. On the other hand, it is usually −5.0 eV or less, preferably −5.5 eV or less. The HOMO energy level of the material of the electron extraction layer 102 is preferably −5.0 eV or less from the viewpoint of preventing movement of holes.

  As a method for calculating the LUMO energy level and the HOMO energy level of the material of the electron extraction layer 102, a cyclic voltammogram measurement method can be given. For example, it can implement with reference to the method as described in well-known literature (International Publication 2011/016430).

  When the material of the electron extraction layer 102 is an organic compound, the glass transition temperature (hereinafter sometimes referred to as Tg) of this compound when measured by a DSC method is not particularly limited, but is not observed, Or it is preferable that it is 55 degreeC or more. That the glass transition temperature is not observed by the DSC method means that there is no glass transition temperature. Specifically, the determination is made based on the presence or absence of a glass transition temperature of 400 ° C. or lower. A material in which the glass transition temperature by the DSC method is not observed is preferable in that it has high thermal stability.

  Among the compounds having a glass transition temperature of 55 ° C. or higher as measured by the DSC method, the glass transition temperature is preferably 65 ° C. or higher, more preferably 80 ° C. or higher, more preferably 110 ° C. or higher, particularly preferably. A compound having a temperature of 120 ° C. or higher is desirable. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but is usually 400 ° C. or lower, preferably 350 ° C. or lower, more preferably 300 ° C. or lower. The material of the electron extraction layer 104 is preferably a material whose glass transition temperature by DSC method is not observed to be 30 ° C. or higher and lower than 55 ° C.

The glass transition temperature in the present specification is defined as a point at which specific heat changes in an amorphous solid, which is a temperature at which local molecular motion is started by thermal energy. When the temperature rises further than Tg, the solid structure changes and crystallization occurs (the temperature at this time is defined as the crystallization temperature (Tc)). When the temperature rises further, it generally melts at the melting point (Tm) and changes to a liquid state. However, these phase transitions may not be observed due to molecular decomposition or sublimation at high temperatures.

  The DSC method is a measurement method of thermophysical properties (differential scanning calorimetry) defined in JIS K-0129 “General Rules for Thermal Analysis”. In order to determine the glass transition temperature more clearly, it is desirable to measure after rapidly cooling a sample once heated to a temperature higher than the glass transition temperature. For example, the measurement can be carried out by a method described in a known document (International Publication No. 2011/016430).

  When the glass transition temperature of the compound used for the electron extraction layer is 55 ° C. or higher, the structure of this compound is difficult to change against external stress such as applied electric field, flowing current, stress due to bending or temperature change. It is preferable in terms of durability. Furthermore, since there is a tendency that the crystallization of the thin film of the compound does not proceed easily, the stability of the electron extraction layer is improved by making it difficult for the compound to change between the amorphous state and the crystalline state in the operating temperature range. Therefore, it is preferable in terms of durability. This effect becomes more prominent as the glass transition temperature of the material is higher.

  The thickness of the electron extraction layer 102 is not particularly limited, but is usually 0.01 nm or more, preferably 0.1 nm or more, more preferably 0.5 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the film thickness of the electron extraction layer 102 is equal to or greater than the lower limit, the function as a buffer material is achieved. When the film thickness of the electron extraction layer 102 is equal to or less than the upper limit, electrons are easily extracted and photoelectric conversion is performed. Efficiency can be improved.

  When an alkali metal salt is used as a material for the electron extraction layer 102, the electron extraction layer 102 can be formed using a vacuum film formation method such as vacuum evaporation or sputtering. In particular, it is desirable to form the electron extraction layer 102 by vacuum deposition using resistance heating. By using vacuum deposition, damage to other layers such as the active layer 103 can be reduced. As for the metal oxide of the n-type semiconductor, for example, when zinc oxide ZnO is used as the material of the electron extraction layer 102, a vacuum film formation method such as a sputtering method can be used. It is desirable to form the layer 102. For example, Sol-Gel Science, C.I. J. et al. Brinker, G.M. W. According to the sol-gel method described by Scherer, Academic Press (1990), the electron extraction layer 102 made of zinc oxide can be formed. The film thickness is usually 0.1 nm or more, preferably 2 nm or more, more preferably 5 nm or more, and usually 1 μm or less, preferably 100 nm or less, more preferably 50 nm or less. If the electron extraction layer 102 is too thin, the effect of improving the electron extraction efficiency is not sufficient, and if it is too thick, the electron extraction layer 102 acts as a series resistance component and tends to impair the characteristics of the element. When the material of the electron extraction layer 102 is an organic compound, in general, when a material having sublimation properties is used, a vacuum film formation method such as a vacuum evaporation method can be used. In addition, when using a material soluble in a solvent, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, slit die coating method, roll brush method, spray coating method, air knife coating method, wire barber coating method, A pipe doctor method, an impregnation / coating method, a curtain coating method, a flexographic printing method, a wet coating method such as an inkjet method, or the like can be used.

When the electron extraction layer 102 is formed by a coating method, a surfactant may be further included in the coating solution. By using the surfactant, the occurrence of dents due to adhesion of fine bubbles or foreign matters and / or uneven coating in the drying process is suppressed. Known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used as the surfactant. Of these, silicon-based surfactants, acetylenic diol-based surfactants, and fluorine-based surfactants are preferable. Only one surfactant may be used as the surfactant.
You may use a seed or more together by arbitrary combinations and ratios.

[1-1-2. Hole extraction layer (104)]
The material of the hole extraction layer 104 is not particularly limited as long as it is a material capable of improving the efficiency of extracting holes from the active layer 103 to the anode 105. Specifically, conductive polymers in which polythiophene, polypyrrole, polyacetylene, triphenylenediamine, polyaniline, etc. are doped with sulfonic acid and / or iodine, polythiophene derivatives having a sulfonyl group as a substituent, conductive organics such as arylamine Examples thereof include compounds, copper oxide, nickel oxide, manganese oxide, molybdenum oxide, vanadium oxide, metal oxide such as tungsten oxide, Nafion, and a p-type semiconductor described later. Among them, a conductive polymer doped with sulfonic acid is preferable, and (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) (PEDOT: PSS) in which a polythiophene derivative is doped with polystyrene sulfonic acid is more preferable. It is. A thin film of metal such as gold, indium, silver or palladium can also be used. A thin film of metal or the like may be formed alone or in combination with the above organic material.

  The thickness of the hole extraction layer 104 is not particularly limited, but is usually 0.2 nm or more. On the other hand, it is usually 400 nm or less, preferably 200 nm or less. When the film thickness of the hole extraction layer 104 is not less than the above lower limit, it functions as a buffer material. When the film thickness of the hole extraction layer 104 is not more than the above upper limit, holes are easily extracted. The photoelectric conversion efficiency can be improved.

  There is no limitation on the formation method of the hole extraction layer 104. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. Also, for example, when using a material soluble in a solvent, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, slit die coating method, roll brush method, spray coating method, air knife coating method, wire barber coating It can be formed by a wet coating method such as a method, a pipe doctor method, an impregnation / coating method, a curtain coating method, a flexographic printing, an ink jet method or the like. When a semiconductor material is used for the hole extraction layer 104, the precursor may be converted into a semiconductor compound after the layer is formed using the precursor, similarly to the low-molecular organic semiconductor compound of the organic active layer described later.

Especially, when using PEDOT: PSS as a material of the hole taking-out layer 104, it is preferable to form the hole taking-out layer 104 by the method of apply | coating a dispersion liquid. PEDOT: The dispersion of PSS, and CLEVIOS ^TM series of Heraeus, Inc., include Agfa Corp. of ORGACON ^TM series and the like.

  When the hole extraction layer 104 is formed by a coating method, a surfactant may be further contained in the coating solution. By using the surfactant, the occurrence of dents due to adhesion of fine bubbles or foreign matters and / or uneven coating in the drying process is suppressed. Known surfactants (cationic surfactants, anionic surfactants, nonionic surfactants) can be used as the surfactant. Of these, silicon-based surfactants, acetylenic diol-based surfactants, and fluorine-based surfactants are preferable. In addition, as surfactant, only 1 type may be used and 2 or more types may be used together by arbitrary combinations and a ratio.

[1-2. Active layer (103)]
The active layer 103 refers to a layer in which photoelectric conversion is performed, and usually includes a p-type semiconductor compound and an n-type semiconductor compound. The p-type semiconductor compound is a compound that works as a p-type semiconductor material, and the n-type semiconductor compound is a compound that works as an n-type semiconductor material. When the organic solar cell element 107 receives light, the light is absorbed by the active layer 103, electricity is generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound, and the generated electricity is extracted from the electrodes 101 and 105.

  As the material of the active layer 103, either an inorganic compound or an organic compound may be used, but a layer that can be formed by a simple coating process is preferable. More preferably, the active layer 103 is an organic active layer made of an organic compound. In the following description, it is assumed that the active layer 103 is an organic active layer.

  As the layer structure of the active layer 103, a thin film stack type in which a p-type semiconductor compound layer and an n-type semiconductor compound layer are stacked, a bulk heterojunction type having a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed, p And a type semiconductor compound layer, a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed (i layer), and an n-type semiconductor compound layer are stacked. Among these, a bulk heterojunction type having a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed is preferable.

  The thickness of the active layer 103 is not particularly limited, but is usually 10 nm or more, preferably 50 nm or more, and is usually 1000 nm or less, preferably 500 nm or less, more preferably 200 nm or less. It is preferable that the thickness of the active layer 103 be equal to or greater than the above lower limit because the uniformity of the film is maintained and a short circuit is less likely to occur. In addition, it is preferable that the thickness of the active layer 103 is equal to or less than the above upper limit in that the internal resistance is small and that the diffusion of charges is good without the electrodes 101 and 105 being too far apart.

  A method for forming the active layer 103 is not particularly limited, but a coating method is preferable. As the coating method, any method can be used. For example, spin coating method, reverse roll coating method, gravure coating method, kiss coating method, slit die coating method, roll brush method, spray coating method, air knife coating method, wire Examples thereof include a barber coating method, a pipe doctor method, an impregnation / coating method, a curtain coating method, flexographic printing, and an ink jet method.

  For example, the p-type semiconductor compound layer and the n-type semiconductor compound layer can be produced by applying a coating liquid containing a p-type semiconductor compound or an n-type semiconductor compound. Moreover, the layer in which the p-type semiconductor compound and the n-type semiconductor compound are mixed can be prepared by applying a coating solution containing the p-type semiconductor compound and the n-type semiconductor compound. As will be described later, the semiconductor compound precursor may be converted into a semiconductor compound after the coating liquid containing the semiconductor compound precursor is applied.

[1-2-1. p-type semiconductor compound]
The p-type semiconductor compound included in the active layer 103 is not particularly limited, and examples thereof include a low molecular organic semiconductor compound and a high molecular organic semiconductor compound.

[1-2-1-1. Low molecular organic semiconductor compound]
The molecular weight of the low-molecular organic semiconductor compound is not particularly limited both at the upper limit and the lower limit, but is usually 5000 or less, preferably 2000 or less, and is usually 100 or more, preferably 200 or more.

Further, the low molecular organic semiconductor compound preferably has crystallinity. The p-type semiconductor compound having crystallinity has a strong intermolecular interaction, and holes generated at the interface between the p-type semiconductor compound and the n-type semiconductor compound in the active layer 103 can be efficiently transported to the anode 105. In the present specification, crystallinity is a property of a compound that takes a three-dimensional periodic arrangement with uniform orientation due to intermolecular interaction or the like. Examples of the crystallinity measuring method include an X-ray diffraction method (XRD) and a field effect mobility measuring method. In particular, in the field effect mobility measurement, the hole mobility is preferably 1.0 × 10 ⁻⁵ cm ² / Vs or more, and more preferably 1.0 × 10 ⁻⁴ cm ² / Vs or more. On the other hand, the hole mobility is usually preferably 1.0 × 10 ⁴ cm ² / Vs or less, more preferably 1.0 × 10 ³ cm ² / Vs or less, and 1.0 × 10 ² cm. More preferably, it is ² / Vs or less.

  The low-molecular organic semiconductor compound is not particularly limited as long as it can function as a p-type semiconductor material. Specifically, condensed aromatic hydrocarbons such as naphthacene, pentacene, or pyrene; α-sexithiophene, etc. Oligothiophenes containing 4 or more thiophene rings; including at least one of thiophene ring, benzene ring, fluorene ring, naphthalene ring, anthracene ring, thiazole ring, thiadiazole ring and benzothiazole ring, and a total of 4 or more linked A phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin and a macrocycle such as a metal complex thereof. Preferably, they are a phthalocyanine compound and its metal complex, or a porphyrin compound and its metal complex.

Examples of the porphyrin compound and its metal complex (Z ¹ in the figure is CH), and the phthalocyanine compound and its metal complex (Z ¹ in the figure are N) include compounds having the following structures.

Here, M represents a metal or two hydrogen atoms, and the metal includes a divalent metal such as Cu, Zn, Pb, Mg, Pd, Ag, Co, or Ni, and an axial ligand 3 Metals having a valence higher than that, for example, TiO, VO, SnCl ₂ , AlCl, InCl, Si, or the like can be used.

R ^{11 to} R ¹⁴ are each independently a hydrogen atom or an alkyl group having 1 to 24 carbon atoms. The alkyl group having 1 to 24 carbon atoms is a saturated or unsaturated chain hydrocarbon group having 1 to 24 carbon atoms or a saturated or unsaturated cyclic hydrocarbon group having 3 to 24 carbon atoms. Among these, a saturated or unsaturated chain hydrocarbon group having 1 to 12 carbon atoms or a saturated or unsaturated cyclic hydrocarbon group having 3 to 12 carbon atoms is preferable.

  Among the phthalocyanine compounds and metal complexes thereof, 29H, 31H-phthalocyanine, copper phthalocyanine complex, zinc phthalocyanine complex, titanium phthalocyanine oxide complex, magnesium phthalocyanine complex, lead phthalocyanine complex or copper 4,4 ′, 4 ″, 4 '' '-Tetraaza-29H, 31H-phthalocyanine complex, more preferably 29H, 31H-phthalocyanine or copper phthalocyanine complex. One of the above compounds may be used, or a mixture of a plurality of compounds may be used.

  Among the porphyrin compounds and metal complexes thereof, 5,10,15,20-tetraphenyl-21H, 23H-porphine, 5,10,15,20-tetraphenyl-21H, 23H-porphine cobalt (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine copper (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine zinc (II), 5,10,15,20- Tetraphenyl-21H, 23H-porphine nickel (II), 5,10,15,20-tetraphenyl-21H, 23H-porphine vanadium (IV) oxide, 5,10,15,20-tetra (4-pyridyl)- 21H, 23H-porphine, 29H, 31H-tetrabenzo [b, g, l, q] porphine, 2 H, 31H-tetrabenzo [b, g, l, q] porphine cobalt (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine copper (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine zinc (II), 29H, 31H-tetrabenzo [b, g, l, q] porphine nickel (II) or 29H, 31H-tetrabenzo [b, g, l, q] porphine vanadium (IV) oxide And preferably 5,10,15,20-tetraphenyl-21H, 23H-porphine or 29H, 31H-tetrabenzo [b, g, l, q] porphine. One of the above compounds may be used, or a mixture of a plurality of compounds may be used.

  Examples of the method for forming a low molecular organic semiconductor compound include a vapor deposition method and a coating method. The latter is preferred because of the process advantage that coating can be formed. When the coating method is used, there is a method of converting a low molecular organic semiconductor compound precursor into a low molecular organic semiconductor compound after coating. A method using a semiconductor compound precursor is more preferable in that coating film formation is easier.

(Low molecular organic semiconductor compound precursor)
A low molecular organic semiconductor compound precursor is a compound that changes its chemical structure and is converted into a low molecular organic semiconductor compound by applying an external stimulus such as heating or light irradiation. The low molecular organic semiconductor compound precursor is preferably excellent in film formability. In particular, in order to be able to apply the coating method, it is preferable that the precursor itself can be applied in a liquid state, or the precursor is highly soluble in some solvent and can be applied as a solution. For this reason, the solubility with respect to the solvent of a low molecular organic-semiconductor compound precursor is usually 0.1 weight% or more, Preferably it is 0.5 weight% or more, More preferably, it is 1 weight% or more. On the other hand, the upper limit is not particularly limited, but is usually 50% by weight or less, preferably 40% by weight or less.

The type of the solvent is not particularly limited as long as it can uniformly dissolve or disperse the semiconductor precursor compound. For example, aliphatic hydrocarbons such as hexane, heptane, octane, isooctane, nonane or decane; toluene, xylene , Aromatic hydrocarbons such as cyclohexylbenzene, chlorobenzene or orthodichlorobenzene; lower alcohols such as methanol, ethanol or propanol; ketones such as acetone, methyl ethyl ketone, cyclopentanone or cyclohexanone; ethyl acetate, butyl acetate or methyl lactate Esters such as: Chloroform, methylene chloride, dichloroethane, trichloroethane, trichloroethylene, and other halogen hydrocarbons; Ethyl ether, tetrahydrofuran, dioxane, and other ethers; Dimethyl Formamide or amides such as dimethylacetamide and the like. Of these, aromatic hydrocarbons such as toluene, xylene, cyclohexylbenzene, chlorobenzene, or orthodichlorobenzene; ketones such as acetone, methyl ethyl ketone, cyclopentanone, or cyclohexanone; chloroform, methylene chloride, dichloroethane, trichloroethane, or trichloroethylene Halogen hydrocarbons; ethers such as ethyl ether, tetrahydrofuran or dioxane. More preferably, non-halogen aromatic hydrocarbons such as toluene, xylene or cyclohexylbenzene; non-halogen ketones such as cyclopentanone or cyclohexanone; non-halogen aliphatic ethers such as tetrahydrofuran or 1,4-dioxane is there. Particularly preferred are non-halogen aromatic hydrocarbons such as toluene, xylene or cyclohexylbenzene. In addition, 1 type of solvent may be used independently and 2 or more types of solvents may be used together by arbitrary combinations and a ratio.

  Furthermore, it is preferable that the low molecular organic semiconductor compound precursor can be easily converted into a semiconductor compound. In the step of converting a low molecular organic semiconductor compound precursor to a semiconductor compound, which will be described later, what kind of external stimulus is given to the semiconductor precursor is arbitrary, but usually heat treatment or light treatment is performed. Preferably, it is heat treatment. In this case, the low-molecular organic semiconductor compound precursor preferably has a solvophilic group with respect to a predetermined solvent, which can be eliminated by a reverse Diels-Alder reaction as a part of the skeleton.

  Moreover, it is preferable that a low molecular organic-semiconductor compound precursor is converted into a semiconductor compound with a high yield through a conversion process. At this time, the yield of the semiconductor compound obtained by conversion from the low molecular organic semiconductor compound precursor is arbitrary as long as the performance of the organic solar cell element is not impaired, but the low molecular organic obtained from the low molecular organic semiconductor compound precursor The yield of the semiconductor compound is usually 90 mol% or more, preferably 95 mol% or more, more preferably 99 mol% or more.

  The low molecular organic semiconductor compound precursor is not particularly limited as long as it has the above characteristics, and specifically, compounds described in JP-A-2007-324587 can be used. Particularly preferred examples include compounds represented by the following formula.

In the above formula, at least one of D ¹ and D ² represents a group that forms a π-conjugated divalent aromatic ring, Z ² -Z ³ is a group that can be removed by heat or light, and Z ² A π-conjugated compound obtained by elimination of —Z ³ represents a low molecular organic semiconductor compound. Further, D ¹ and D ² which are not a group forming a π-conjugated divalent aromatic ring represent a substituted or unsubstituted ethenylene group.

In the compound represented by the above formula, Z ² —Z ³ is eliminated by heat or light as shown in the following chemical reaction formula to form a π-conjugated compound having high planarity. This produced π-conjugated compound is a low-molecular organic semiconductor compound. This low molecular organic semiconductor compound is used as a material having p-type semiconductor characteristics.

  The following are mentioned as an example of a low molecular organic-semiconductor compound precursor. In the following, t-Bu represents a t-butyl group, and M is the same as described for porphyrin and phthalocyanine.

  Specific examples of the conversion of the low-molecular organic semiconductor compound precursor into the low-molecular organic semiconductor compound include the following.

  The low molecular organic semiconductor compound precursor may have a structure in which positional isomers exist, and in that case, it may be a mixture of a plurality of positional isomers. A mixture of a plurality of positional isomers is preferable because it has a higher solubility in a solvent than a low-molecular organic semiconductor compound precursor composed of a single positional isomer component, and is easy to form a coating film. The reason why the solubility of the mixture of multiple positional isomers is high is that the detailed mechanism is not clear, but the crystallinity of the compound itself is potentially retained, but the mixture of multiple isomers is mixed in the solution. It is assumed that three-dimensional regular intermolecular interaction becomes difficult. The solubility of the mixture of a plurality of regioisomers in a non-halogen solvent is usually 0.1% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more. Although there is no restriction | limiting in an upper limit, Usually, it is 50 weight% or less, More preferably, it is 40 weight% or less.

[1-2-1-2. Polymeric organic semiconductor compound]
The polymer organic semiconductor compound is not particularly limited, and is a conjugated polymer semiconductor such as polythiophene, polyfluorene, polyphenylene vinylene, polythienylene vinylene, polyacetylene or polyaniline; a polymer such as oligothiophene substituted with an alkyl group or other substituents Semiconductor; and the like. Moreover, the semiconductor polymer which copolymerized 2 or more types of monomer units is also mentioned. The conjugated polymers, ^{e.g., Handbook of Conducting Polymers, 3 rd} Ed. (2 volumes), 2007, Materials Science and Engineering, 2001, 32, 1-40, Pure Appl. Chem. Use polymers that can be synthesized by a combination of polymers described in known literature such as 2002, 74, 2031-3044, Handbook of THIOPHENE-BASED MATERIALS (2 volumes), 2009, and derivatives thereof, and combinations of the described monomers. Can do. The polymer organic semiconductor compound used as the p-type semiconductor compound may be a single compound or a mixture of a plurality of compounds.

  The monomer skeleton and monomer substituent of the polymer organic semiconductor compound can be selected to control the solubility, crystallinity, film-forming property, HOMO energy level, LUMO energy level, and the like. Moreover, it is preferable that the polymer organic semiconductor compound is soluble in an organic solvent in that the active layer 103 can be formed by a coating method when an organic solar cell element is produced. Specific examples of the polymer organic semiconductor compound include the following, but are not limited thereto.

  Among the p-type semiconductor compounds, the low-molecular organic semiconductor compound is preferably a condensed aromatic hydrocarbon such as naphthacene, pentacene, or pyrene, a phthalocyanine compound and a metal complex thereof, or a porphyrin compound such as tetrabenzoporphyrin (BP) and The metal complex and the polymer organic semiconductor compound is a conjugated polymer semiconductor such as polythiophene. The p-type semiconductor compound used in the active layer 103 may be a single compound or a mixture of multiple compounds.

  The low-molecular organic semiconductor compound and / or the high-molecular organic semiconductor compound may have some self-organized structure in the film-formed state, or may be in an amorphous state.

  The HOMO (highest occupied molecular orbital) energy level of the p-type semiconductor compound is not particularly limited, and can be selected according to the type of the n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the HOMO energy level of the p-type semiconductor compound is usually −5.7 eV or more, more preferably −5.5 eV or more, on the other hand, usually −4.6 eV or less. Preferably it is -4.8 eV or less. When the HOMO energy level of the p-type semiconductor compound is −5.7 eV or more, the characteristics as a p-type semiconductor are improved, and when the HOMO energy level of the p-type semiconductor compound is −4.6 eV or less, Stability is improved and the open circuit voltage (Voc) is also improved.

  The LUMO (lowest unoccupied molecular orbital) energy level of the p-type semiconductor compound is not particularly limited, but can be selected according to the type of the n-type semiconductor compound described later. In particular, when a fullerene compound is used as an n-type semiconductor compound, the LUMO energy level of the p-type semiconductor compound is usually −3.7 eV or more, preferably −3.6 eV or more. On the other hand, it is usually −2.5 eV or less, preferably −2.7 eV or less. When the LUMO energy level of the p-type semiconductor is −2.5 eV or less, the band gap is adjusted, light energy having a long wavelength can be effectively absorbed, and the short-circuit current density is improved. When the LUMO energy level of the p-type semiconductor compound is −3.7 eV or more, electron transfer to the n-type semiconductor compound is likely to occur and the short-circuit current density is improved.

[1-2-2. n-type semiconductor compound]
The n-type semiconductor compound is not particularly limited. Specifically, a fullerene compound, 8-
Quinolinol derivative metal complexes typified by hydroxyquinoline aluminum; condensed ring tetracarboxylic acid diimides such as naphthalenetetracarboxylic acid diimide or perylenetetracarboxylic acid diimide; perylene diimide derivatives, terpyridine metal complexes, tropolone metal complexes, flavonol metal complexes, perinones Derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazole derivatives, benzthiazole derivatives, benzothiadiazole derivatives, oxadiazole derivatives, thiadiazole derivatives, triazole derivatives, aldazine derivatives, bisstyryl derivatives, pyrazine derivatives, phenanthroline derivatives, quinoxaline derivatives, benzoquinoline derivatives , Bipyridine derivatives, borane derivatives, anthracene, pyrene, naphthacene or pentacene All fluoride condensed polycyclic aromatic hydrocarbon and the like; single-walled carbon nanotubes, and the like.

  Among them, fullerene compounds, borane derivatives, thiazole derivatives, benzothiazole derivatives, benzothiadiazole derivatives, N-alkyl-substituted naphthalenetetracarboxylic acid diimides and N-alkyl-substituted perylene diimide derivatives are preferable, and fullerene compounds, N- Alkyl substituted perylene diimide derivatives and N-alkyl substituted naphthalene tetracarboxylic acid diimides are more preferred. One of the above compounds may be used, or a mixture of a plurality of compounds may be used. Examples of the n-type semiconductor compound include an n-type polymer semiconductor compound.

  The LUMO energy level of the n-type semiconductor compound is not particularly limited. For example, the value with respect to the vacuum level calculated by the cyclic voltammogram measurement method is usually −3.85 eV or more, preferably −3.80 eV or more. . In order to efficiently transfer electrons from a p-type semiconductor compound to an n-type semiconductor compound, the relative relationship of LUMO energy levels between the p-type semiconductor compound and the n-type semiconductor compound is important. Specifically, the LUMO energy level of the p-type semiconductor compound is above the LUMO energy level of the n-type semiconductor compound by a predetermined value, in other words, the electron affinity of the n-type semiconductor compound is p-type semiconductor compound. It is preferable that a predetermined energy is larger than the electron affinity. Since the open circuit voltage (Voc) depends on the difference between the HOMO energy level of the p-type semiconductor compound and the LUMO energy level of the n-type semiconductor compound, increasing the LUMO of the n-type semiconductor compound tends to increase the Voc. On the other hand, the LUMO value is usually −1.0 eV or less, preferably −2.0 eV or less, more preferably −3.0 eV or less, and still more preferably −3.3 eV or less. By lowering the LUMO energy level of the n-type semiconductor compound, electrons tend to move and the short circuit current (Jsc) tends to increase.

  As a method for calculating the LUMO energy level of an n-type semiconductor compound, there are a theoretically calculated method and a method of actually measuring. Theoretically calculated methods include semi-empirical molecular orbital methods and non-empirical molecular orbital methods. Examples of the actual measurement method include an ultraviolet-visible absorption spectrum measurement method and a cyclic voltammogram measurement method. Among them, the cyclic voltammogram measurement method is preferable.

  The HOMO energy level of the n-type semiconductor compound is not particularly limited, but is usually −5.0 eV or less, preferably −5.5 eV or less. On the other hand, it is usually −7.0 eV or more, preferably −6.6 eV or more. It is preferable that the HOMO energy level of the n-type semiconductor compound is −7.0 eV or more because light absorption of the n-type semiconductor compound can also be used for power generation. The HOMO energy level of the n-type semiconductor compound is preferably −5.0 eV or less from the viewpoint of preventing reverse movement of holes.

The electron mobility of the n-type semiconductor compound is not particularly limited, but is usually 1.0 × 10 ⁻⁶ cm ² / Vs or more, preferably 1.0 × 10 ⁻⁵ cm ² / Vs or more. 0 × 10 ⁻⁵ cm ² / Vs or more is more preferable, and 1.0 × 10 ⁻⁴ cm ² / Vs or more is more preferable. On the other hand, it is usually 1.0 × 10 ³ cm ² / Vs or less, preferably 1.0 × 10 ² cm ² / Vs or less, and more preferably 5.0 × 10 ¹ cm ² / Vs or less. When the n-type semiconductor compound has an electron mobility of 1.0 × 10 ⁻⁶ cm ² / Vs or more, effects such as an improvement in the electron diffusion rate, an improvement in the short-circuit current, and an improvement in the conversion efficiency of the organic solar cell element can be obtained. This is preferable. As a method for measuring electron mobility, there is a field effect transistor (FET) method, which can be carried out by a method described in a known document (Japanese Patent Laid-Open No. 2010-045186).

  The solubility of the n-type semiconductor compound in toluene at 25 ° C. is usually 0.5% by weight or more, preferably 0.6% by weight or more, and more preferably 0.7% by weight or more. On the other hand, it is usually preferably 90% by weight or less, more preferably 80% by weight or less, and further preferably 70% by weight or less. When the solubility of the n-type semiconductor compound in toluene at 25 ° C. is 0.5% by weight or more, the dispersion stability of the n-type semiconductor compound in the solution is improved, and aggregation, sedimentation, separation, and the like are less likely to occur. Therefore, it is preferable.

  Hereinafter, examples of preferable n-type semiconductor compounds will be described.

[1-2-2-1. Fullerene compound]
As a fullerene compound, what has the partial structure represented by general formula (n1), (n2), (n3), and (n4) is mentioned as a preferable example.

In the above formula, FLN represents fullerene, which is a carbon cluster having a closed shell structure. The carbon number of fullerene is not particularly limited as long as it is an even number of usually 60 or more and 130 or less. Examples of fullerenes include C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C ₉₄ , C _96, and higher carbon clusters having more carbon than these. . Among these, _C60 or _C70 is preferable. As fullerenes, carbon-carbon bonds on some fullerene rings may be broken. Moreover, some of the carbon atoms constituting the fullerene may be replaced with other atoms. Further, the fullerene may include a metal atom, a non-metal atom, or an atomic group composed of these in a fullerene cage.

a, b, c and d are integers, and the sum of a, b, c and d is usually 1 or more, and usually 5 or less, preferably 3 or less. The partial structures in (n1), (n2), (n3) and (n4) are bonded to the same 5-membered ring or 6-membered ring in the fullerene skeleton. In the general formula (n1), —R ²¹ and — (CH ₂ ) _L are bonded to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. . In the general formula (n2), —C (R ²⁵ ) (R ²⁶ ) —N (R ²⁷ ) —C is the same for two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. (R ²⁸ ) (R ²⁹ ) — are added to form a 5-membered ring. In the general formula (n3), —C (R ³⁰ ) (R ³¹ ) —C—C—C (R) with respect to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton. ³² ) ( ^R33 )-is added to form a 6-membered ring. In the general formula (n4), —C (R ³⁴ ) (R ³⁵ ) — is added to two adjacent carbon atoms on the same 5-membered ring or 6-membered ring in the fullerene skeleton to form a 3-membered ring. Forming. L is an integer of 1 to 8. L is preferably an integer of 1 to 4, more preferably an integer of 1 to 2.

R ²¹ in the general formula (n1) is an alkyl group having 1 to 14 carbon atoms which may have a substituent, an alkoxy group having 1 to 14 carbon atoms which may have a substituent, or a substituent. An aromatic group which may have a group.

  The alkyl group is preferably an alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group or an isobutyl group, and even more preferably a methyl group or an ethyl group. . The alkoxy group is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 6 carbon atoms, and particularly preferably a methoxy group or an ethoxy group. The aromatic group is preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, more preferably a phenyl group, a thienyl group, a furyl group, or a pyridyl group. More preferred are groups or thienyl groups.

  Although it does not specifically limit as a substituent which said alkyl group, an alkoxy group, and an aromatic group may have, A halogen atom or a silyl group is preferable. As the halogen atom, a fluorine atom is preferable. The silyl group is preferably a diarylalkylsilyl group, a dialkylarylsilyl group, a triarylsilyl group or a trialkylsilyl group, more preferably a dialkylarylsilyl group, and even more preferably a dimethylarylsilyl group.

R ^{22 to} R ²⁴ in the general formula (n1) may each independently have a hydrogen atom, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. It is an aromatic group.

  As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, and a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, or an n-hexyl group is preferable. . The substituent that the alkyl group may have is preferably a halogen atom. As the halogen atom, a fluorine atom is preferable. The alkyl group substituted with a fluorine atom is preferably a perfluorooctyl group, a perfluorohexyl group or a perfluorobutyl group.

  The aromatic group is preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, more preferably a phenyl group, a thienyl group, a furyl group, or a pyridyl group. More preferred are groups or thienyl groups. The substituent that the aromatic group may have is not particularly limited, but is a fluorine atom, an alkyl group having 1 to 14 carbon atoms, a fluorinated alkyl group having 1 to 14 carbon atoms, or a carbon atom having 1 to 14 carbon atoms. An alkoxy group or an aromatic group having 3 to 10 carbon atoms is preferred, a fluorine atom or an alkoxy group having 1 to 14 carbon atoms is more preferred, and a methoxy group, n-butoxy group or 2-ethylhexyloxy group is still more preferred. When the aromatic group has a substituent, the number is not limited, but is preferably 1 or more and 3 or less, and more preferably 1. When the aromatic group has a plurality of substituents, the types of the substituents may be different, but are preferably the same.

R ^{25 to} R ²⁹ in the general formula (n2) may each independently have a hydrogen atom, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. It is an aromatic group.

  The alkyl group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-hexyl group or octyl group, and more preferably a methyl group. The substituent that the alkyl group may have is not particularly limited, but a halogen atom is preferable. As the halogen atom, a fluorine atom is preferable. The alkyl group substituted with a fluorine atom is preferably a perfluorooctyl group, a perfluorohexyl group or a perfluorobutyl group.

  As the aromatic group, an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms is preferable, a phenyl group or a pyridyl group is more preferable, and a phenyl group is further preferable. Although it does not specifically limit as a substituent which an aromatic group may have, Preferably they are a fluorine atom, a C1-C14 alkyl group, or a C1-C14 alkoxy group. The alkyl group may be substituted with a fluorine atom. More preferably, it is an alkoxy group having 1 to 14 carbon atoms, and more preferably a methoxy group. When it has a substituent, the number is not limited, but it is preferably 1 or more and 3 or less, more preferably 1. The types of substituents may be different, but are preferably the same.

Ar ¹ in the general formula (n3) is an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms, preferably A phenyl group, a naphthyl group, a biphenyl group, a thienyl group, a furyl group, a pyridyl group, a pyrimidyl group, a quinolyl group or a quinoxalyl group, more preferably a phenyl group, a thienyl group or a furyl group.

  Although there is no limitation as a substituent which may have, an amino group which may be substituted with a fluorine atom, a chlorine atom, a hydroxyl group, a cyano group, a silyl group, a boryl group or an alkyl group, having 1 to 14 carbon atoms An alkyl group, an alkoxy group having 1 to 14 carbon atoms, an alkylcarbonyl group having 2 to 14 carbon atoms, an alkylthio group having 1 to 14 carbon atoms, an alkenyl group having 2 to 14 carbon atoms, and 2 to 14 carbon atoms An alkynyl group, an ester group having 2 to 14 carbon atoms, an arylcarbonyl group having 3 to 20 carbon atoms, an arylthio group having 2 to 20 carbon atoms, an aryloxy group having 2 to 20 carbon atoms, and 6 or more carbon atoms An aromatic hydrocarbon group having 20 or less or a heterocyclic group having 2 to 20 carbon atoms is preferable, a fluorine atom, an alkyl group having 1 to 14 carbon atoms, 1 or less carbon atoms 1 An alkoxy group, having 2 to 14 ester groups carbons, an alkyl group or having 3 to 20 arylcarbonyl group carbons of 2 to 14 carbon atoms and more preferable. The alkyl group having 1 to 14 carbon atoms may be substituted with 1 or 2 or more fluorine atoms.

  The alkyl group having 1 to 14 carbon atoms is preferably a methyl group, an ethyl group or a propyl group. The alkoxy group having 1 to 14 carbon atoms is preferably a methoxy group, an ethoxy group, or a propoxy group. The alkylcarbonyl group having 1 to 14 carbon atoms is preferably an acetyl group. The ester group having 2 to 14 carbon atoms is preferably a methyl ester group or an n-butyl ester group. The arylcarbonyl group having 3 to 20 carbon atoms is preferably a benzoyl group.

  When it has a substituent, the number is not limited, but it is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less. When there are a plurality of substituents, the types may be different, but are preferably the same.

R ^{30 to} R ³³ in the general formula (n3) each independently have a hydrogen atom, an alkyl group which may have a substituent, an amino group which may have a substituent, or a substituent. It is an optionally substituted alkoxy group or an optionally substituted alkylthio group. R ³⁰ or R ³¹ may be bonded to any one of R ³² and R ³³ to form a ring. As a structure in the case of forming a ring, the structure shown to the general formula (n5) which is a bicyclo structure which the aromatic group condensed is mentioned, for example.

F In the general formula (n5) has the same meaning as c, Z ⁴ is an oxygen atom, a sulfur atom, an amino group, an alkylene group or an arylene group. The alkylene group preferably has 1 to 2 carbon atoms. The arylene group preferably has 5 to 12 carbon atoms, and examples thereof include a phenylene group. The amino group may be substituted with an alkyl group having 1 to 6 carbon atoms such as a methyl group or an ethyl group. The alkylene group is an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. The aromatic heterocyclic group may be substituted. The arylene group is an alkoxy group having 1 to 6 carbon atoms such as a methoxy group, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 2 to 20 carbon atoms. The aromatic heterocyclic group may be substituted.

  The structure represented by the formula (n5) is particularly preferably a structure represented by the following formula (n6) or formula (n7).

R ^{34 to} R ³⁵ in the general formula (n4) each independently have a hydrogen atom, an alkoxycarbonyl group, an alkyl group having 1 to 14 carbon atoms which may have a substituent, or a substituent. An aromatic group that may be present.

  The alkoxy group constituting the alkoxycarbonyl group is preferably an alkoxy group having 1 to 12 carbon atoms or a fluorinated alkoxy group having 1 to 12 carbon atoms, more preferably an alkoxy group having 1 to 12 carbon atoms, and a methoxy group. Ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, n-hexoxy group, octoxy group, 2-propylpentoxy group, 2-ethylhexoxy group, cyclohexylmethoxy group or benzyloxy group A methoxy group, an ethoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group or an n-hexoxy group is particularly preferable.

  As the alkyl group, a linear alkyl group having 1 to 8 carbon atoms is preferable, and an n-propyl group is more preferable. The substituent that the alkyl group may have is not particularly limited, but is preferably an alkoxycarbonyl group. The alkoxy group constituting the alkoxycarbonyl group is preferably an alkoxy group having 1 to 14 carbon atoms or a fluorinated alkoxy group, more preferably a hydrocarbon group having 1 to 14 carbon atoms, a methoxy group, an ethoxy group, n- Propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, n-hexoxy group, octoxy group, 2-propylpentoxy group, 2-ethylhexoxy group, cyclohexylmethoxy group or benzyloxy group are more preferable, methoxy group or n A butoxy group is particularly preferred.

  As the aromatic group, an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aromatic heterocyclic group having 2 to 20 carbon atoms is preferable, and a phenyl group, a biphenyl group, a thienyl group, a furyl group, or a pyridyl group is preferable. More preferred are a phenyl group and a thienyl group. The substituent that the aromatic group may have is preferably an alkyl group having 1 to 14 carbon atoms, a fluorinated alkyl group having 1 to 14 carbon atoms, or an alkoxy group having 1 to 14 carbon atoms. An alkoxy group having a number of 1 or more and 14 or less is more preferable, and a methoxy group or 2-ethylhexyloxy group is particularly preferable. When it has a substituent, the number is not limited, but it is preferably 1 or more and 3 or less, more preferably 1. The types of substituents may be different or the same, preferably the same.

As the structure of the general formula (n4), preferably R ³⁴ and R ³⁵ are both alkoxycarbonyl groups, R ³⁴ and R ³⁵ are both aromatic groups, or R ³⁴ is an aromatic group and R ^{And those in which 35} is a 3- (alkoxycarbonyl) propyl group.

  As the fullerene compound, one kind of the above compounds may be used, or a mixture of plural kinds of compounds may be used.

  In order to form a fullerene compound by a coating method, it is preferable that the fullerene compound itself can be applied in a liquid state, or that the fullerene compound is highly soluble in some solvent and can be applied as a solution. As a preferable range of solubility, the solubility in toluene at 25 ° C. is usually 0.1% by weight or more, preferably 0.4% by weight or more, more preferably 0.7% by weight or more. It is preferable that the solubility of the fullerene compound is 0.1% by weight or more because the dispersion stability of the fullerene compound in the solution increases and aggregation, sedimentation, separation, and the like are less likely to occur.

  The solvent for dissolving the fullerene compound is not particularly limited as long as it is a nonpolar organic solvent, but a non-halogen solvent is preferable. Although it is possible to use a halogen-based solvent such as dichlorobenzene, an alternative is demanded from the viewpoint of environmental load. Examples of non-halogen solvents include non-halogen aromatic hydrocarbons. Of these, toluene, xylene, cyclohexylbenzene, and the like are preferable.

(Method for producing fullerene compound)
Although there is no restriction | limiting in particular as a manufacturing method of a fullerene compound, For example, the synthesis | combination of the fullerene compound which has a partial structure (n1) is international publication 2008/059771 or J.N. Am. Chem. Soc. , 2008, 130 (46), 15429-15436.

  Synthesis of fullerene compounds having a partial structure (n2) is described in J. Org. Am. Chem. Soc. 1993, 115, 9798-9799, Chem. Mater. 2007, 19, 5363-5372 and Chem. Mater. It can be carried out according to the description of known documents such as 2007, 19, 5194-5199.

  Synthesis of a fullerene compound having a partial structure (n3) is described in Angew. Chem. Int. Ed. Engl. 1993, 32, 78-80, Tetrahedron Lett. It can be carried out according to the description of known documents such as 1997, 38, 285-288, WO 2008/018931 and WO 2009/086212.

  Synthesis of fullerene compounds having a partial structure (n4) is described in J. Org. Chem. Soc. Perkin Trans. 1, 1997 1595, Thin Solid Films 489 (2005) 251-256, Adv. Funct. Mater. 2005, 15, 1979-1987 and J. Org. Org. Chem. It can be carried out according to the description of known documents such as 1995, 60, 532-538.

[1-2-2-2. N-alkyl substituted perylene diimide derivatives]
N-alkyl-substituted perylene diimide derivatives are not particularly limited, and specifically, International Publication No. 2008/063609, International Publication No. 2009/115553, International Publication No. 2009/098250, International Publication No. Examples thereof include compounds described in 2009/000756 and International Publication No. 2009/091670. These compounds are preferable in that they have high electron mobility and can absorb light in the visible range, and thus can contribute to both charge transport and power generation.

[1-2-2-3. Naphthalenetetracarboxylic acid diimide]
The naphthalenetetracarboxylic acid diimide is not particularly limited, and specific examples thereof include compounds described in International Publication No. 2008/063609, International Publication No. 2007/146250 and International Publication No. 2009/000756. It is done. These compounds are preferable because they have high electron mobility, high solubility, and excellent coating properties.

[1-2-2-4. N-type polymer semiconductor compound]
The n-type polymer semiconductor compound is not particularly limited, but condensed ring tetracarboxylic acid diimides such as naphthalene tetracarboxylic acid diimide and perylene tetracarboxylic acid diimide, perylene diimide derivatives, benzimidazole derivatives, benzoxazole derivatives, thiazoles N-type polymer semiconductor comprising at least one of a derivative, a benzothiazole derivative, a benzothiadiazole derivative, an oxadiazole derivative, a thiadiazole derivative, a triazole derivative, a pyrazine derivative, a phenanthroline derivative, a quinoxaline derivative, a bipyridine derivative and a borane derivative Compounds and the like.

Among them, a polymer having at least one of a borane derivative, a thiazole derivative, a benzothiazole derivative, a benzothiadiazole derivative, an N-alkyl-substituted naphthalenetetracarboxylic acid diimide and an N-alkyl-substituted perylene diimide derivative as a constituent unit is provided. Preferably, an n-type polymer semiconductor compound having at least one of N-alkyl-substituted perylene diimide derivative and N-alkyl-substituted naphthalenetetracarboxylic acid diimide as a constituent unit is more preferable. One of the above compounds may be used as the n-type polymer semiconductor compound, or a mixture of a plurality of compounds may be used.

  Specific examples of the n-type polymer semiconductor compound include compounds described in International Publication No. 2009/098253, International Publication No. 2009/098250, International Publication No. 2010/012710, and International Publication No. 2009/098250. Can be mentioned. Since these compounds can absorb light in the visible range, they can contribute to power generation, are preferred because of their high viscosity and excellent coating properties.

[1-3. Substrate (106)]
The organic solar cell element 107 has a base material 106 that serves as a support. That is, the electrodes 101 and 105 and the active layer 103 are formed on the substrate.

  The material of the substrate 106 is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferable examples of the material of the substrate 106 include inorganic materials such as quartz, glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer , Polyolefin such as fluororesin film, vinyl chloride or polyethylene; organic material such as cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, polynorbornene or epoxy resin; paper material such as paper or synthetic paper; Examples include composite materials such as stainless steel, titanium, or aluminum that have a surface coated or laminated to provide insulation, but a flexible and transparent substrate is obtained. Pancreatic Therefore, a resin film made of an organic material is preferred.

  Examples of the glass include soda glass, blue plate glass, and non-alkali glass. Among these, alkali-free glass is preferable in that there are few eluted ions from the glass.

There is no restriction | limiting in the shape of the base material 106, For example, things, such as plate shape, a film form, or a sheet form, can be used. Moreover, although there is no restriction | limiting in the film thickness of the base material 106, Usually, it is 5 micrometers or more, Preferably it is 20 micrometers or more, On the other hand, it is 20 mm or less normally, Preferably it is 10 mm or less. It is preferable that the thickness of the substrate is equal to or more than the above lower limit because the possibility that the strength of the organic solar cell element is insufficient is reduced. It is preferable that the film thickness of the substrate is not more than the above upper limit because the cost is suppressed and the weight does not increase.
When the material of the substrate 106 is glass, the film thickness is usually 0.01 mm or more, preferably 0.1 mm or more, and is usually 1 cm or less, preferably 0.5 cm or less. It is preferable that the film thickness of the glass substrate 106 is equal to or more than the above lower limit because the mechanical strength increases and it is difficult to break. In addition, it is preferable that the film thickness of the glass substrate 106 be equal to or less than the above upper limit because the weight does not increase.

[1-4. Electrode (101, 105)]
The electrodes 101 and 105 have a function of collecting holes and electrons generated by light absorption. Therefore, the pair of electrodes may include an electrode 105 suitable for collecting holes (hereinafter also referred to as an anode) and an electrode 101 suitable for collecting electrons (hereinafter referred to as a cathode). ) Are preferably used. Any one of the pair of electrodes may be translucent, and both may be translucent. Translucency means that sunlight passes through 40% or more. Moreover, it is preferable that the sunlight transmittance of the transparent electrode is 70% or more in order to allow light to reach the active layer 103 through the transparent electrode. The light transmittance can be measured with a normal spectrophotometer.

The anode 105 is generally composed of a conductive material having a work function higher than that of the cathode,
This is an electrode having a function of smoothly extracting holes generated in the active layer 103.

  Examples of the material of the anode 105 include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium-zirconium oxide (IZO), titanium oxide, indium oxide, and zinc oxide. A metal such as gold, platinum, silver, chromium or cobalt, or an alloy thereof; These substances are preferable because they have a high work function, and further, a conductive polymer material represented by PEDOT: PSS in which a polythiophene derivative is doped with polystyrene sulfonic acid can be stacked. When laminating such a conductive polymer, the work function of this conductive polymer material is high, so even if it is not a material with a high work function as described above, it is suitable for cathodes such as Al and Mg. Metals can also be widely used. PEDOT: PSS in which a polythiophene derivative is doped with polystyrene sulfonic acid, or a conductive polymer material in which polypyrrole, polyaniline, or the like is doped with iodine or the like can also be used as an anode material. When the anode 105 is a transparent electrode, it is preferable to use a light-transmitting conductive metal oxide such as ITO, zinc oxide, or tin oxide, and ITO is particularly preferable.

  The film thickness of the anode 105 is not particularly limited, but is usually 10 nm or more, preferably 20 nm or more, and more preferably 50 nm or more. On the other hand, it is usually 10 μm or less, preferably 1 μm or less, more preferably 500 nm or less. When the film thickness of the anode 105 is equal to or greater than the lower limit, sheet resistance is suppressed, and when the film thickness of the anode 105 is equal to or smaller than the upper limit, light is efficiently converted into electricity without reducing light transmittance. be able to. When the anode 105 is a transparent electrode, it is necessary to select a film thickness that can achieve both light transmittance and sheet resistance.

  The sheet resistance of the anode 105 is not particularly limited, but is usually 1Ω / □ or more, on the other hand, 1000Ω / □ or less, preferably 500Ω / □ or less, more preferably 100Ω / □ or less.

  Examples of a method for forming the anode 105 include a vacuum film forming method such as a vapor deposition method or a sputtering method, or a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  The cathode 101 is generally an electrode made of a conductive material having a low work function and having a function of smoothly extracting electrons generated in the active layer 103. The cathode 101 is adjacent to the electron extraction layer 102.

  Examples of the material of the cathode 101 include metals such as platinum, gold, silver, copper, iron, tin, zinc, aluminum, indium, chromium, lithium, sodium, potassium, cesium, calcium, and magnesium, and alloys thereof; Examples include inorganic salts such as lithium and cesium fluoride; metal oxides such as nickel oxide, aluminum oxide, lithium oxide, and cesium oxide. These materials are preferable because they are materials having a low work function. Similarly to the anode 105, the cathode 101 can be made of a material having a high work function by using an n-type semiconductor such as titania having conductivity as the electron extraction layer 102. From the viewpoint of electrode protection, the material of the cathode 101 is preferably a metal such as platinum, gold, silver, copper, iron, tin, aluminum, calcium or indium, or an alloy using these metals such as indium tin oxide. .

The film thickness of the cathode 101 is not particularly limited, but is usually 10 nm or more, preferably 20 nm or more, more preferably 50 nm or more. On the other hand, it is usually 10 μm or less, preferably 1 μm or less, more preferably 500 nm or less. When the film thickness of the cathode 101 is equal to or greater than the lower limit, sheet resistance is suppressed, and when the film thickness of the cathode 101 is equal to or less than the upper limit, light is efficiently converted into electricity without decreasing the light transmittance. be able to. When the cathode 101 is a transparent electrode, it is necessary to select a film thickness that achieves both light transmittance and sheet resistance.

  The sheet resistance of the cathode 101 is not particularly limited, but is usually 1000Ω / □ or less, preferably 500Ω / □ or less, and more preferably 100Ω / □ or less. Although there is no restriction on the lower limit, it is usually 1Ω / □ or more.

  As a method for forming the cathode 101, there are a vacuum film-forming method such as an evaporation method or a sputtering method, or a wet coating method in which an ink containing nanoparticles or a precursor is applied to form a film.

  Furthermore, the anode 105 and the cathode 101 may have a laminated structure of two or more layers. In addition, characteristics (electric characteristics, wetting characteristics, etc.) may be improved by performing surface treatment on the anode 105 and the cathode 101.

  After laminating the anode 105 and the cathode 101, the organic solar cell element is usually at a temperature range of 50 ° C. or higher, preferably 80 ° C. or higher, usually 300 ° C. or lower, preferably 280 ° C. or lower, more preferably 250 ° C. or lower. It is preferable to heat (this step may be referred to as an annealing treatment step). By performing the annealing process at a temperature equal to or higher than the lower limit, the adhesion between the layers of the organic solar cell element, for example, the adhesion between the electron extraction layer 102 and the cathode 101 and / or the electron extraction layer 102 and the active layer 103 is improved. Since an effect is acquired, it is preferable. By improving the adhesion between the layers, the thermal stability and durability of the organic solar cell element can be improved. It is preferable to set the temperature of the annealing treatment step to the upper limit or less because the possibility that the organic compound in the active layer 103 is thermally decomposed is reduced. In the annealing treatment step, stepwise heating may be performed within the above temperature range.

  The heating time is usually 1 minute or longer, preferably 3 minutes or longer, and usually 3 hours or shorter, preferably 1 hour or shorter. The annealing treatment step is preferably terminated when the open-circuit voltage, the short-circuit current, and the fill factor, which are parameters of the solar cell performance, reach a constant value. Further, the annealing treatment step is preferably performed under normal pressure and in an inert gas atmosphere.

  The method for heating is not particularly limited, but preferred is a method using heating with hot air, irradiation with far infrared rays and / or near infrared rays, and an organic solar cell element may be placed on a heat source such as a hot plate, an oven or the like. An organic solar cell element may be placed in the heated atmosphere. The heating may be performed in a batch mode or a continuous mode, but is preferably performed in a continuous mode.

[1-5. Photoelectric conversion characteristics]
The photoelectric conversion characteristics of the organic solar cell element 107 can be obtained as follows. The organic solar cell element 107 is irradiated with light having an AM1.5G condition at an irradiation intensity of 100 mW / cm ^{2 using a} solar simulator, and current-voltage characteristics are measured. From the obtained current-voltage curve, photoelectric conversion characteristics such as photoelectric conversion efficiency (PCE), short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), series resistance, and shunt resistance can be obtained.

  Although there is no special restriction | limiting, the photoelectric conversion efficiency of the organic solar cell element which concerns on this invention is 1% or more normally, Preferably it is 1.5% or more, More preferably, it is 2% or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better.

Moreover, as a method of measuring the durability of the organic solar cell element, there is a method of obtaining a photoelectric conversion efficiency maintenance rate before and after exposing the organic solar cell element to the atmosphere.
(Maintenance rate) = (Photoelectric conversion efficiency after N hours of atmospheric exposure) / (Photoelectric conversion efficiency immediately before atmospheric exposure)

  In order to put an organic solar cell element into practical use, it is important to have high photoelectric conversion efficiency and high durability in addition to simple and inexpensive manufacture. From this viewpoint, the maintenance rate of photoelectric conversion efficiency before and after exposure to the atmosphere for one week is preferably 60% or more, more preferably 80% or more, and the higher the better.

<2. Undercoat layer>
In the organic solar cell of the present invention, an undercoat layer is laminated between the organic solar cell element described above and a barrier layer described later. An undercoat layer is laminated | stacked on the surface which laminated | stacked the electrode and active layer of the organic solar cell element. By providing the undercoat layer, the flatness of the surface on which the barrier layer is formed can be improved, high sealing performance can be exhibited even with a thin barrier layer, and the production rate can be improved. Moreover, by using an undercoat layer as the base of the barrier layer, the denseness of the barrier layer can be improved and high sealing performance can be exhibited. Therefore, deterioration of the organic solar cell element can be suppressed. Furthermore, by using an undercoat layer between the organic solar cell element and the barrier layer, the adhesion of the barrier layer is increased, and interface peeling can be suppressed.

  The material for the undercoat layer is not particularly limited, but the thermoplastic resin composition, the thermosetting resin composition, or the active energy ray curable resin composition can be easily obtained as a material that can easily obtain the above-described effect and can be applied to a wet process described later. The material which forms the film which consists of organic polymer compositions, such as a thing, is mentioned. The active energy ray-curable resin composition is, for example, a resin composition that undergoes a curing reaction upon irradiation with ultraviolet rays, visible rays, electron beams, X-rays, and the like to increase the molecular weight.

  Examples of the thermoplastic resin composition include acrylic resins, polyester resins, polycarbonate resins, polyurethane resins, ethylene vinyl alcohol resins, polyvinyl alcohol resins, silicone resins, phenoxy resins, and polyimide resins.

  As a thermosetting resin composition or an active energy ray-curable resin composition, a thermosetting property or activity can be obtained by introducing a copolymer component during polymerization of the thermoplastic resin or by modifying molecular chain terminals or side chains. What has energy beam curability can be used. For example, a polyester resin, a polyurethane resin with a hydroxyl group introduced into the molecular chain end or side chain, and a curing reaction by adding an isocyanate compound or the like to make a thermosetting resin, acrylic resin Similarly, a reactive acrylate group is introduced into a resin, a polyurethane resin, a polyester resin, or the like to obtain an ultraviolet curable resin.

  In the thermosetting resin composition and the active energy ray curable resin composition, in order to ensure the desired cured properties, a monomer having a curable functional group (monomer) and also having a curable functional group It is preferable to use a polymer having a low molecular weight called an oligomer or a prepolymer or the like, which cannot exhibit the properties of a polymer by itself. Moreover, by using at least two or more kinds of blend compositions such as these curable monomers, curable oligomers, curable polymers, or non-curable polymers, it is possible to obtain good coating properties and cured film properties. preferable.

  As thermosetting resin compositions, polyester polyols, polyether polyols and the like as main ingredients are cured with an isocyanate-based cross-linking agent, generally called dry laminate adhesives, bisphenol A and other epoxy resins and amines, acid anhydrides Or a mixture of curing agents such as imidazole can be used.

Various adhesives for dry laminating are available on the market, and when the undercoat layer is required to be moist and heat resistant, obtain the desired one appropriately depending on the required performance, such as selecting a retort resistant grade. I can do it. In addition, a polyester system containing a hydroxyl group that is soluble in a general-purpose organic solvent, has a relatively low molecular weight, and has reactivity with a crosslinking agent such as isocyanate, such as “Byron (registered trademark)” manufactured by Toyobo Co., Ltd. It is good also as an adhesive for dry laminates having desired physical properties by appropriately adjusting the molecular weight, the glass transition temperature, the hydroxyl value, and the structure of the isocyanate curing agent of the polyester resin.

  In the case of an ultraviolet curable resin composition, a photopolymerization initiator, a photopolymerization initiator, an ordinary monomer or oligomer that forms a cured film by causing a polymerization reaction by irradiation of active energy rays in the molecule, and if necessary, a polymer. In addition, if necessary, a photosensitizer or the like is added and adjusted by diluting with an organic solvent as appropriate in order to ensure coatability. Here, the compounding components such as the monomer and the oligomer may be a single composition or may be composed of two or more kinds.

  Examples of the ultraviolet curable monomer include monofunctional and bifunctional or more polyfunctional monomers. Monofunctional (meth) acrylate monomers include acryloylmorpholine, dimethylacrylamide, diethylacrylamide, diisopropylacrylamide, isobornyl acrylate, 2-hydroxy (meth) acrylate, 2-hexyl (meth) acrylate, and phenoxyethyl (meth) acrylate. Etc. Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate. Furthermore, examples of the trifunctional or higher functional (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (tetra) (meth) acrylate, and dipentaerythritol hexa (meth) acrylate.

As an ultraviolet curing oligomer, the molecular weight of one to several acryloyl groups (CH ₂ ═CHCO—) or methacryloyl groups (CH ₂ ═CCH ₃ CO—) in the molecule is from several hundred to several hundreds. Refers to a compound. Typical examples are mono (meth) acrylates such as epoxy, epoxidized oil, urethane oligomer, polyester oligomer, polyether oligomer, (meth) acrylate ester oligomer, di (meth) acrylate, tri (meth) acrylate And polyfunctional (meth) acrylates.

The resin composition used for the undercoat layer of the present invention is a thermosetting resin composition or an ultraviolet curable resin composition from the viewpoints of ease of film formation, heat resistance stability of the formed undercoat layer, and the like. Is preferred. These resins may be used alone or in combination of two or more. Further, these resins may contain silicon oxide, titanium oxide, aluminum oxide or the like to form an organic-inorganic hybrid resin. The silicon oxide hybrid resin has a structure in which a silicon compound that forms a silica structure by heating is copolymerized with a molecular chain of a curable resin, or a nano-sized silica particle that is finely dispersed in a curable resin matrix. Etc. can be used.
Especially, since an undercoat layer has the function to relieve | moderate the stress of a barrier layer, it is preferable to contain 1 or more types selected from the polyester resin, polyurethane resin, and acrylic resin which can adjust an elasticity modulus in a comparatively low range.

The method for laminating the undercoat layer is not particularly limited, but spin coating, dipping, spraying, reverse roll coating, gravure coating, kiss coating, air knife coating, pipe doctor method, impregnation / coating method, curtain Preferred are those by a wet coating method (wet process) under atmospheric pressure, such as a coating method, screen printing, flexographic printing, gravure printing, ink jet printing, die coating, roll coating, and bar coating. In the wet application method, a layer is formed by supplying a layer forming material in the form of a solution when forming a layer. By adopting a wet coating method under atmospheric pressure, a smooth film surface can be easily formed at low cost against fine irregularities generated by coating of the organic solar cell element.
For example, after applying a resin solution using the above resin composition and a solvent, it can be laminated by solvent removal, heat curing, ultraviolet curing or the like. An appropriate solvent is selected according to the resin to be used. For example, in the case of an acrylic resin, toluene or the like can be used, and in the case of a solvent-soluble polyester resin such as “Byron”, 2-butanone can be used. When the resin composition is composed of only a curable monomer or curable oligomer having fluidity in a normal temperature range, it may be applied without adding a solvent (no solvent). When the solvent is removed, it is preferably carried out at a temperature equal to or higher than the boiling point of the solvent at the removal rate point, and is preferably carried out at a temperature equal to or lower than the Tg of the material of the active layer from the viewpoint of suppressing the performance degradation of the organic solar cell element.
Alternatively, a dry process method such as sputtering or flash vapor deposition may be used, or the above-described resin in the form of a film may be laminated by thermocompression bonding. Further, it may be an undercoat layer composed of two or more layers having the same film forming method or different composition types and composition ratios.

  The elastic modulus measured in the normal temperature region (23 ° C.) of the undercoat layer is usually 10 MPa or more, preferably 100 MPa or more, more preferably 200 MPa or more. The upper limit is usually 20 GPa or less, preferably 10 GPa or less, more preferably 5 GPa or less, and particularly preferably 3 GPa or less. The elastic modulus is measured according to, for example, JIS K 7171. By making the undercoat layer have the above elastic modulus, the undercoat layer acts as a stress relaxation layer between the barrier layer and the organic solar cell element, prevents the organic solar cell from being destroyed, and improves durability and flexibility. I can do it.

Moreover, it is preferable that the elasticity modulus of an undercoat layer is low with respect to the elasticity modulus of a barrier layer, and is 1/100 or less, More preferably, it is 1/500 or less.
Further, the thermal expansion coefficient of the undercoat layer is preferably 20 ppm / ° C. or more, and more preferably 50 ppm / ° C. or more. On the other hand, 200 ppm / ° C. or less is preferable, and 100 ppm / ° C. or less is more preferable.

  The thickness of the undercoat layer is usually 0.1 μm or more, preferably 0.2 μm or more, and more preferably 0.5 μm or more. On the other hand, the upper limit is usually 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. By making such a range, the stress buffering effect can be appropriately exhibited while maintaining the flexibility of the organic solar cell, and a smooth barrier layer-forming surface can be formed. The adhesion of can be improved.

In the case where the barrier layer side of the organic solar cell of the present invention is a light incident surface (substrate structure), the undercoat layer preferably transmits light from the viewpoint of preventing light absorption. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. Particularly preferably, it is 97% or more. This is to convert more sunlight into electrical energy.
On the other hand, when the substrate side of the organic solar cell is a light incident surface (super straight structure), it may be opaque such as black or metallic luster in addition to the light transmitting surface. The light transmitted through the active layer can be arbitrarily set depending on the purpose, such as the light reflected again toward the active layer.

<3. Barrier layer>
In the organic solar cell of the present invention, a barrier layer is laminated on an undercoat layer laminated on an organic solar cell element. The barrier layer is a layer that prevents deterioration of the organic solar cell element due to heat and deterioration of the organic solar cell element due to gas such as moisture and oxygen.
Organic solar cell elements including organic semiconductors tend to be sensitive to moisture and oxygen, and the electrodes and organic semiconductor layers may be deteriorated by moisture and oxygen. Therefore, it is preferable to protect from water and oxygen by coating the organic solar cell element with a barrier layer. By doing so, the fall of the output of an organic solar cell, etc. can be prevented.

  For the barrier layer, inorganic compounds such as metals, oxides, nitrides, and oxynitrides are preferably used. Specifically, the main component is an oxide, nitride, oxynitride, or mixture of at least one metal selected from the group consisting of silicon, aluminum, indium, tin, zinc, titanium, tantalum, and tungsten. It is preferable that It should be noted that other components may coexist without departing from the spirit of the present invention. Besides these, a resin having a high barrier property, such as polyvinyl alcohol, can also be used. Among the above, silicon oxide, silicon nitride, aluminum oxide, titanium oxide, and zinc oxide are preferable from the viewpoint of high barrier properties and transparency.

  As a method of laminating the barrier layer, a vacuum film formation method (dry process) by any one of vacuum vapor deposition, sputtering, ion plating, chemical vapor deposition (CVD), flash vapor deposition, or a combination thereof can be used. The vacuum film formation method means a method of forming a thin film in a vacuum state or under reduced pressure. A dense barrier layer can be formed by the vacuum film formation method as described above.

The elastic modulus measured in the normal temperature range (23 ° C.) of the barrier layer is usually 1 GPa or more, preferably 5 GPa or more, more preferably 10 GPa or more. The upper limit is usually 500 GPa or less, preferably 200 GPa or less, and more preferably 100 GPa or less.
The thickness of the barrier layer is usually 20 nm or more, preferably 50 nm or more, and more preferably 100 nm or more. On the other hand, the upper limit is usually 10 μm or less, preferably 5 μm or less, and more preferably 1 μm or less. By setting it as such a range, the softness | flexibility of an organic solar cell can be maintained, ensuring sufficient barrier property.

The barrier layer used in the present invention preferably satisfies the water vapor transmission rate described below. The water vapor permeability Pd at 1 μm thickness of the barrier layer needs to be 10 ⁻¹ g / m ² / day or less in a 40 ° C. and 90% RH environment in order to block the entry of moisture from the outside. Is 10 ⁻² g / m ² / day or less, more preferably 10 ⁻³ g / m ² / day or less, and 10 ⁻⁴ g / m ² / day or less. However, if the current technology is transparent and flexible and the barrier performance is increased, the manufacturing cost will be increased accordingly, so that it is usually 10 ⁻³ g / m ² / day to 10 ⁻⁴ g / m ^2. It is practically most preferable barrier performance to be in the range of / day. The water vapor transmission rate is measured in an environment of 40 ° C. and 90% RH by a measurement using an apparatus equipped with a humidity sensor, an infrared sensor, and a gas chromatograph according to JIS K7129, or by a cup method (JIS Z0208).

In general, the oxygen permeability of the barrier layer is such that the oxygen permeability per day of a unit area (1 m ² ) at a thickness of 1 μm in a 25 ° C. environment is 1 cc / m ² / day / atm or less. Preferably, it is 1 × 10 ⁻¹ cc / m ² / day / atm or less, more preferably 1 × 10 ⁻² cc / m ² / day / atm or less, and further preferably 1 × 10 1. ⁻³ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁴ cc / m ² / day / atm or less is particularly preferable, and 1 × 10 ⁻⁵ cc / m ² / day. / Atm or less is particularly preferable. The more oxygen does not permeate, the less degradation of the organic solar cell due to oxidation. The oxygen permeability can be measured with an apparatus based on a differential pressure method according to JIS K7126A, or an apparatus equipped with an infrared sensor and a gas chromatograph based on an isobaric method according to JIS K7126B.

In the organic solar cell of the present invention, the barrier layer preferably transmits visible light from the viewpoint of not preventing light absorption. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, still more preferably 90% or more, particularly preferably 95% or more. Among these, 97% or more is particularly preferable.

<4. Overcoat layer>
In the present invention, an overcoat layer can be laminated on the barrier layer. By using the overcoat layer, the barrier layer can be protected, the barrier performance can be further improved, and deterioration of the organic solar cell element can be suppressed.
For the overcoat layer, a resin such as an epoxy resin, an acrylic resin, a polyester resin, or polyimide can be used, but an epoxy resin, an acrylic resin, or a polyester resin is preferable. The resin used for the overcoat layer is preferably thermosetting or ultraviolet curable. These resins may be used alone or in combination of two or more.
The overcoat layer has a function of protecting the barrier layer. Therefore, it is preferable that the material for the overcoat layer includes one or more selected from polyester resins, epoxy resins, and acrylic resins that can easily adjust the elastic modulus within a relatively high range.
Moreover, as a combination of the material of the undercoat layer and the material of the overcoat layer, the material of the undercoat layer contains at least one selected from polyester resin, polyurethane resin, and acrylic resin, and the material of the overcoat layer However, it is preferable to include one or more selected from polyester resins, epoxy resins, and acrylic resins.

  As the method for laminating the overcoat layer, the atmospheric pressure such as spin coat method, dipping method, spray method, screen printing, gravure printing, flexographic printing, ink jet printing, die coating, roll coating, bar coating, etc. The thing by the lower wet application system is mentioned. Moreover, you may use the method by dry processes, such as sputtering and flash vapor deposition, and what laminated | stacked said resin in the film form can be laminated | stacked by thermocompression bonding etc., or it can also laminate | stack via an adhesive layer.

The elastic modulus measured in the normal temperature region (23 ° C.) of the overcoat layer is usually 10 MPa or more, preferably 100 MPa or more, more preferably 200 MPa or more. The upper limit is usually 20 GPa or less, preferably 10 GPa or less, more preferably 5 GPa or less, and still more preferably 3 GPa or less. Due to the function required for the overcoat layer, it is preferable to have a higher elastic modulus than the above-mentioned undercoat layer.
In the present invention, the relationship between the elastic modulus of the undercoat layer and the overcoat layer is preferably such that the elastic modulus of the undercoat layer is from 1/10 to 2 times the elastic modulus of the overcoat layer. It is more preferable that the ratio is not more than twice.
Further, the elastic modulus of the undercoat layer is 20 GPa or less, the elastic modulus of the overcoat layer is 100 MPa or more, and the elastic modulus of the undercoat layer is 1/10 to 2 times the elastic modulus of the overcoat layer. Preferably there is.

  The thickness of the overcoat layer is usually 0.1 μm or more, preferably 0.2 μm or more, and more preferably 0.5 μm or more. On the other hand, the upper limit is usually 10 μm or less, preferably 5 μm or less, and more preferably 2 μm or less. By being above the lower limit, the protective effect of the barrier layer can be improved. Moreover, the flexibility of an organic solar cell can be improved by being below the said upper limit.

  Moreover, in this invention, from a viewpoint which does not prevent the light absorption of an organic solar cell, a thing which permeate | transmits visible light is preferable for an overcoat layer. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, still more preferably 90% or more, particularly preferably 95% or more. Among these, 97% or more is particularly preferable.

In addition, the thermal expansion coefficient of the overcoat layer is preferably 20 ppm / ° C. or more, more preferably 50 ppm / ° C. or more, preferably 200 ppm / ° C. or less, and more preferably 100 ppm / ° C. or less. Furthermore, the pencil hardness of the overcoat layer is preferably B or more, and more preferably H or more. Then, it is preferable that the moisture permeability in the thickness 10μm in terms of the overcoat layer is not more than 10g / m ² / day, more preferably at most 10g / m ² / day.

<5. Film-like member>
In the present invention, a film-like member can be further provided on the barrier layer or the overcoat layer. The film-like member protects the organic solar cell from the device installation environment such as temperature change, humidity change, light, wind and rain, and prevents deterioration.

  Since the film-like member is located on the outermost layer of the organic solar cell, it has suitable performance as a surface covering material for the organic solar cell, such as weather resistance, heat resistance, transparency, water repellency, contamination resistance, and mechanical strength. In addition, it preferably has the property of maintaining it for a long period of time in outdoor exposure.

  Furthermore, since organic solar cells are often heated by receiving light, it is preferable that the film-like member also has heat resistance. From this viewpoint, the melting point of the constituent material of the film-like member is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 350 ° C. or lower, preferably 320 ° C. or lower, more preferably It is 300 degrees C or less. By increasing the melting point, it is possible to reduce the possibility that the film-like member melts and deteriorates when the organic solar battery is used.

  The material which comprises a film-like member is arbitrary. Examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyvinyl chloride resin, fluorine resin, polyethylene terephthalate, polyethylene Examples thereof include polyester resins such as naphthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicone resins, and polycarbonate resins.

  Among them, fluorine resin is preferable, and specific examples thereof include polytetrafluoroethylene (PTFE), 4-fluoroethylene-perchloroalkoxy copolymer (PFA), 4-fluoroethylene-6-fluoride. Propylene copolymer (FEP), 2-ethylene-4-fluoroethylene copolymer (ETFE), poly-3-fluoroethylene chloride (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), etc. Can be mentioned.

  Note that the film-like member may be formed of one type of material or may be formed of two or more types of materials. The film-like member may be formed of a single layer film, but may be a laminated film including two or more layers.

  The thickness of the film-like member is usually 5 μm or more, preferably 10 μm or more, more preferably 20 μm or more, and usually 200 μm or less, preferably 100 μm or less, more preferably 50 μm or less. Increasing the thickness tends to increase mechanical strength, and decreasing the thickness tends to increase flexibility. For this reason, it is desirable to set it as the said range as a range which has both advantages.

Further, the film-like member may be subjected to surface treatment such as corona treatment or plasma treatment in order to improve adhesiveness with other films.
In addition, ultraviolet rays, heat rays, antifouling properties, hydrophilicity, hydrophobicity, antifogging properties, abrasion resistance, electrical conductivity, antireflection, antiglare properties, light diffusion, light scattering, wavelength conversion, gas barrier are applied to film-like members. You may give functions, such as sex. In particular, since the organic solar cell is exposed to strong ultraviolet rays from sunlight, it preferably has an ultraviolet blocking function.

  As a method for imparting such a function, a layer having a function may be laminated on the film-like member by coating film formation or the like, or a material exhibiting the function may be dissolved and dispersed in the film-like member. You may make it contain.

  The method for laminating the film-like member is not particularly limited, and examples thereof include a method of heat-pressing by a thermal laminating method, but it is preferable to laminate via an adhesive layer. The material of the adhesive layer is not particularly limited, but usually, for example, ethylene-vinyl acetate copolymer (EVA) resin, polyvinyl butyral (PVB) resin, modified polyethylene resin modified with maleic acid or silane, modified polypropylene resin, epoxy Materials such as adhesives, urethane adhesives, and acrylic adhesives are used. The thickness of the adhesive layer is preferably 1 μm or more, and more preferably 5 μm or more. On the other hand, the upper limit is preferably 100 μm or less, and more preferably 40 μm or less.

  Further, the film-like member and the adhesive layer are preferably those that transmit visible light from the viewpoint of not impeding the light absorption of the organic solar cell. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 75% or more, preferably 80% or more, more preferably 85% or more, further preferably 90% or more, and particularly preferably 95% or more. Particularly preferably, it is 97% or more.

  Hereinafter, although the organic solar cell of this invention is demonstrated with reference to drawings, this invention is not necessarily limited only to such an embodiment.

  FIG. 2 shows one embodiment of the organic solar cell of the present invention. In FIG. 2, an undercoat layer 221 and a barrier layer 222 are laminated on the organic solar cell element 107 on which a pair of electrodes, active layers and the like (101 to 105 in FIG. 1) are formed on the base material 106. An organic solar cell 230 is formed. Since the undercoat layer 221 smoothes fine irregularities generated by the formation of the organic solar cell element 107, a dense barrier layer 222 can be formed. In addition, the undercoat layer 221 having an appropriate elastic modulus functions as a stress relaxation layer between the organic solar cell element 107 and the barrier layer 222.

  In FIG. 3, an overcoat layer 223 is further laminated on the barrier layer 222. The barrier layer 222 is protected by the overcoat layer 223, and excellent barrier performance can be maintained for a long time.

  In FIG. 4, a film-like member 225 is further laminated on the overcoat layer 223 via an adhesive layer 224. The film-like member 225 provides weather resistance and heat resistance, and can increase the service life even under a harsh environment such as being exposed to rain wind or ultraviolet rays.

<6. Organic Thin Film Solar Cell Module Using the Organic Solar Cell of the Present Invention>
The organic solar cell 230 according to the present invention is preferably used as an organic solar cell module, particularly an organic solar cell of an organic thin film solar cell module.

FIG. 5 is a cross-sectional view schematically showing a configuration of an organic thin film solar cell module as an example of use of the organic solar cell of the present invention. As shown in FIG. 5, the organic thin-film solar cell module 14 of this embodiment includes a weather-resistant protective film 1, an ultraviolet cut film 2, a gas barrier film 3, a getter material film 4, a sealing material 5, and organic sun The battery 6, the sealing material 7, the getter material film 8, the gas barrier film 9, and the back sheet 10 are provided in this order. And the light is irradiated from the side (downward in the figure) where the weather-resistant protective film 1 is formed, and the organic solar cell 6 generates power.

In addition, since the organic solar cell 6 of this invention has the upper and lower surfaces pinched | interposed by the base material and the barrier layer, and has a sealing structure in itself, it is not necessary to use the getter material film 8 and / or the gas barrier film 9. . In addition, even when the getter material film 8 and / or the gas barrier film 9 is used, since these films can be made thinner and have lower performance than conventional organic thin film solar cell modules, organic solar cells can be used. The film thickness can be reduced and the flexibility can be improved.
Furthermore, even in applications where gas barrier properties are particularly required, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, the getter material film 8 and / or The gas barrier film 9 may not be used.

[6-1. Weatherproof protective film (1)]
The weather-resistant protective film 1 is a film that protects the organic solar cell 6 from weather changes. By covering the organic solar cell 6 with the weather-resistant protective film 1, the organic solar cell 6 and the like are protected from weather changes and the power generation capacity is kept high. Since the weather resistant protective film 1 is located in the outermost layer of the organic thin film solar cell module 14, the organic thin film solar cell module 14 such as weather resistance, heat resistance, transparency, water repellency, contamination resistance and / or mechanical strength is used. It is preferable to have a property suitable as a surface coating material and to maintain it for a long period of time in outdoor exposure.

  Moreover, it is preferable that the weather-resistant protective film 1 transmits visible light from the viewpoint of not hindering the light absorption of the organic solar cell 6. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, and the upper limit is not limited. Furthermore, since the organic thin film solar cell module 14 is often heated by receiving light, it is preferable that the weather-resistant protective film 1 also has heat resistance. From this viewpoint, the melting point of the constituent material of the weather-resistant protective film 1 is usually 100 ° C. or higher and 350 ° C. or lower.

  The material which comprises the weather-resistant protective film 1 is arbitrary if the organic solar cell 6 can be protected from a weather change. Examples of the material include polyethylene resin, polypropylene resin, cyclic polyolefin resin, AS (acrylonitrile-styrene) resin, ABS (acrylonitrile-butadiene-styrene) resin, polyvinyl chloride resin, fluorine resin, polyethylene terephthalate, polyethylene Examples thereof include polyester resins such as naphthalate, phenol resins, polyacrylic resins, polyamide resins such as various nylons, polyimide resins, polyamide-imide resins, polyurethane resins, cellulose resins, silicon resins, and polycarbonate resins.

  In addition, the weather-resistant protective film 1 may be formed with 1 type of material, and may be formed with 2 or more types of materials. Moreover, although the weather-resistant protective film 1 may be formed with the single layer film, the laminated | multilayer film provided with the film of two or more layers may be sufficient as it.

  The thickness of the weather-resistant protective film 1 is not particularly defined, but is usually 10 μm or more and 200 μm or less.

  Moreover, you may perform surface treatment, such as a corona treatment and / or a plasma treatment, for the weather-resistant protective film 1 in order to improve the adhesiveness with another film.

  It is preferable to provide the weatherproof protective film 1 on the outer side of the organic thin film solar cell module 14 as much as possible. This is because more of the constituent members of the organic thin film solar cell module 14 can be protected.

[6-2. UV cut film (2)]
The ultraviolet cut film 2 is a film that prevents the transmission of ultraviolet rays. By providing the ultraviolet cut film 2 on the light receiving portion of the organic thin film solar cell module 14 and covering the light receiving surface 6a of the organic solar cell 6 with the ultraviolet cut film 2, the organic solar cell 6 and, if necessary, the gas barrier films 3, 9 etc. Can be protected from ultraviolet rays and the power generation capacity can be kept high.

  The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut film 2 is preferably such that the transmittance of ultraviolet rays (for example, wavelength of 300 nm) is 50% or less, and there is no limit on the lower limit. Moreover, it is preferable that the ultraviolet cut film 2 transmits visible light from the viewpoint of not hindering the light absorption of the organic solar cell 6. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, and the upper limit is not limited.

  Furthermore, since the organic thin film solar cell module 14 is often heated by receiving light, the ultraviolet cut film 2 preferably has resistance to heat. From this viewpoint, the deflection temperature under load of the constituent material of the ultraviolet cut film 2 is usually 80 ° C. or higher and 350 ° C. or lower.

  Moreover, it is preferable that the ultraviolet cut film 2 is high in flexibility, has good adhesion to an adjacent film, and can cut water vapor and oxygen.

  The material which comprises the ultraviolet cut film 2 is arbitrary if the intensity | strength of an ultraviolet-ray can be weakened. Examples of the material include films formed by blending an ultraviolet absorber with an epoxy, acrylic, urethane, or ester resin. Further, a film in which a layer of an ultraviolet absorbent dispersed or dissolved in a resin (hereinafter referred to as “ultraviolet absorbing layer” as appropriate) is formed on a base film may be used.

  Examples of the ultraviolet absorber that can be used include salicylic acid-based, benzophenone-based, benzotriazole-based, and cyanoacrylate-based ones. In addition, a ultraviolet absorber may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio. As described above, a film in which an ultraviolet absorbing layer is formed on a base film can also be used as the ultraviolet absorbing film. Such a film can be produced, for example, by applying a coating solution containing an ultraviolet absorber on a substrate film and drying it.

  Although the material of a base film is not specifically limited, For example, polyester is mentioned at the point from which the balance of heat resistance and a softness | flexibility is obtained.

  Examples of specific products of the ultraviolet cut film 2 include cut ace (MKV Plastic Co., Ltd.). In addition, the ultraviolet cut film 2 may be formed with 1 type of material, and may be formed with 2 or more types of materials.

  Further, the ultraviolet cut film 2 may be formed of a single layer film, but may be a laminated film including two or more layers. The thickness of the ultraviolet cut film 2 is not particularly limited, but is usually 5 μm or more and 200 μm or less.

Although the ultraviolet cut film 2 should just be provided in the position which covers at least one part of the light-receiving surface 6a of the organic solar cell 6, Preferably it is provided in the position which covers all the light-receiving surfaces 6a of the organic solar cell 6. FIG.
However, the ultraviolet cut film 2 may be provided at a position other than the position covering the light receiving surface 6 a of the organic solar cell 6.

[6-3. Gas barrier film (3)]
The gas barrier film 3 is a film that prevents permeation of water and oxygen. By covering the organic solar cell 6 with the gas barrier film 3, the organic solar cell 6 can be protected from water and oxygen, and the power generation capacity can be kept high.

The degree of moisture resistance required for the gas barrier film 3 varies depending on the type of the organic solar cell 6 and the like, but the water vapor transmission rate per unit area (1 m ² ) per day is usually 1 × 10 ^−1. It is preferable that it is below g / m < ² > / day, and there is no restriction | limiting in a minimum.

The degree of oxygen permeability required for the gas barrier film 3 varies depending on the type of the organic solar cell 6 and the like, but the oxygen permeability per unit area (1 m ² ) is usually 1 × 10 ^−. It is preferably ¹ cc / m ² / day / atm or less, and the lower limit is not limited.

  Moreover, it is preferable that the gas barrier film 3 transmits visible light from the viewpoint of not hindering the light absorption of the organic solar cell 6. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  Furthermore, since the organic thin film solar cell module 14 is often heated by receiving light, the gas barrier film 3 preferably has heat resistance. From this viewpoint, the melting point of the constituent material of the gas barrier film 3 is usually 100 ° C. or higher and 350 ° C. or lower.

  The specific configuration of the gas barrier film 3 is arbitrary as long as the organic solar cell 6 can be protected from water. However, since the manufacturing cost increases as the amount of water vapor or oxygen that can permeate the gas barrier film 3 increases, it is preferable to use an appropriate film considering these points comprehensively.

Particularly suitable gas barrier film 3 includes, for example, a film obtained by vacuum-depositing SiO _x on a base film such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

  In addition, the gas barrier film 3 may be formed with 1 type of material, and may be formed with 2 or more types of materials. The gas barrier film 3 may be formed of a single layer film, but may be a laminated film including two or more layers.

  The thickness of the gas barrier film 3 is not particularly defined, but is usually 5 μm or more and 200 μm or less.

  As long as the gas barrier film 3 can cover the organic solar cell 6 and protect it from moisture and oxygen, the formation position is not limited. It is preferable to cover the back surface (the surface opposite to the light receiving surface; the upper surface in FIG. 5). This is because the organic thin-film solar cell module 14 often has a front surface and a back surface formed in a larger area than the other surfaces. In this embodiment, the gas barrier film 3 covers the front surface of the organic solar cell 6, and a gas barrier film 9 described later covers the back surface of the organic solar cell 6. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, the getter material film 8 and / or the gas barrier film 9 may not be used depending on the application. Good.

[6-4. Getter material film (4)]
The getter material film 4 is a film that absorbs moisture and / or oxygen. By covering the organic solar cell 6 with the getter material film 4, the organic solar cell 6 and the like are protected from moisture and / or oxygen, and the power generation capacity is kept high. Here, unlike the gas barrier film 3 as described above, the getter material film 4 does not prevent moisture permeation but absorbs moisture. By using a film that absorbs moisture, when the organic solar cell 6 is covered with the gas barrier film 3 or the like, the getter material film 4 captures moisture that slightly enters the space formed by the gas barrier films 3 and 9. The influence of moisture on the organic solar cell 6 can be eliminated.

The degree of moisture absorption capacity of the getter material film 4 is usually 0.1 mg / cm ² or more, and although there is no upper limit, it is usually 10 mg / cm ² or less. Further, when the organic solar cell 6 is covered with the gas barrier films 3 and 9 or the like by the getter material film 4 absorbing oxygen, the oxygen that slightly enters the space formed by the gas barrier films 3 and 9 is obtained as the getter material. The film 4 can capture and eliminate the influence of oxygen on the organic solar cell 6.

  Furthermore, it is preferable that the getter material film 4 transmits visible light from the viewpoint of not hindering the light absorption of the organic solar cell 6. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  Furthermore, since the organic thin-film solar cell module 14 is often heated by receiving light, the getter material film 4 preferably has resistance to heat. From this viewpoint, the melting point of the constituent material of the getter material film 4 is usually 100 ° C. or higher and 350 ° C. or lower.

  The material constituting the getter material film 4 is arbitrary as long as it can absorb moisture and / or oxygen. Examples of the material include alkali metal, alkaline earth metal or alkaline earth metal oxides; alkali metal or alkaline earth metal hydroxides; silica gel, zeolitic compounds, magnesium sulfate. And sulfates such as sodium sulfate and nickel sulfate; and organometallic compounds such as aluminum metal complexes and aluminum oxide octylates. Specifically, examples of the alkaline earth metal include Ca, Sr, and Ba. Examples of the alkaline earth metal oxide include CaO, SrO, and BaO. In addition, Zr-Al-BaO and aluminum metal complexes are also included. Specific product names include, for example, OleDry (Futaba Electronics).

  Examples of the substance that absorbs oxygen include activated carbon, silica gel, activated alumina, molecular sieve, magnesium oxide, and iron oxide. In addition, Fe, Mn, Zn, and inorganic salts such as sulfates, chlorides, and nitrates of these metals are also included.

  In addition, the getter material film 4 may be formed of one type of material or may be formed of two or more types of materials. The getter material film 4 may be formed of a single layer film, but may be a laminated film including two or more layers.

  The thickness of the getter material film 4 is not particularly specified, but is usually 5 μm or more and 200 μm or less.

The formation position of the getter material film 4 is not limited as long as it is in the space formed by the gas barrier films 3 and 9, but the front surface of the organic solar cell 6 (light receiving surface side surface; lower surface in FIG. 5). And it is preferable to cover the back surface (surface opposite to the light receiving surface; upper surface in FIG. 5). This is because the organic thin film solar cell module 14 often has a front surface and a back surface formed in a larger area than the other surfaces, and therefore moisture and oxygen tend to enter through these surfaces. From this viewpoint, the getter material film 4 is preferably provided between the gas barrier film 3 and the organic solar cell 6. In this embodiment, the getter material film 4 covers the front surface of the organic solar cell 6, the getter material film 8 described later covers the back surface of the organic solar cell 6, and the getter material films 4 and 8 are respectively the organic solar cell 6 and the gas barrier film 3. , 9 are located between them. In addition, when using a highly waterproof sheet such as a sheet in which a fluororesin film is bonded to both surfaces of an aluminum foil as the back sheet 10 described later, the getter material film 8 and / or the gas barrier film 9 may not be used depending on the application. Good.

[6-5. Encapsulant (5)]
The sealing material 5 is a film that reinforces the organic solar cell 6. Since the organic solar cell 6 is thin, the strength is usually weak, and the strength of the organic thin film solar cell module tends to be weak. However, the strength can be maintained high by the sealing material 5.

  Moreover, it is preferable that the sealing material 5 has high strength from the viewpoint of maintaining the strength of the organic thin-film solar cell module 14. The specific strength is related to the strength of the weatherproof protective film 1 other than the sealing material 5 and the strength of the back sheet 10 and is generally difficult to define, but the entire organic thin-film solar cell module 14 has good bending workability. It is desirable to have strength that does not cause peeling of the bent portion.

  Moreover, it is preferable that the sealing material 5 permeate | transmits visible light from a viewpoint which does not prevent the light absorption of the organic solar cell 6. FIG. For example, the transmittance of visible light (wavelength 360 to 830 nm) is usually 60% or more, and there is no upper limit.

  The thickness of the sealing material 5 is not particularly specified, but is usually 2 μm or more and 700 μm or less.

  The T-type peel adhesion strength of the sealing material 5 to the substrate is usually 1 N / inch or more and usually 2000 N / inch or less. It is preferable that the T-type peel adhesive strength is 1 N / inch or more in terms of ensuring the long-term durability of the module. It is preferable that the T-type peel adhesive strength is 2000 N / inch or less in that the base material, the barrier film, and the adhesive can be separated and discarded when the solar cell is discarded. The T-type peel adhesion strength is measured by a method according to JIS K6854.

  The constituent material of the sealing material 5 is not particularly limited as long as it has the above characteristics, but sealing of organic / inorganic solar cells, sealing of organic / inorganic LED elements, sealing of electronic circuit boards, etc. In general, a sealing material generally used can be used.

  Specifically, a thermosetting resin composition or a thermoplastic resin composition and an active energy ray curable resin composition can be mentioned. The active energy ray-curable resin composition is, for example, a resin that is cured by ultraviolet rays, visible light, electron beams, or the like. More specifically, an ethylene-vinyl acetate copolymer (EVA) resin composition, a hydrocarbon resin composition, an epoxy resin composition, a polyester resin composition, an acrylic resin composition, and a urethane resin composition. Or a silicon-based resin composition, etc., depending on the main chain, branched chain, terminal chemical modification of each polymer, adjustment of molecular weight, additives, etc., thermosetting, thermoplastic and active energy ray curable, etc. The characteristics are expressed.

  Moreover, since the organic thin-film solar cell module 14 is often heated by receiving light, it is preferable that the sealing material 5 also has heat resistance. From this viewpoint, the melting point of the constituent material of the sealing material 5 is usually 100 ° C. or higher and 350 ° C. or lower.

The density of the constituent material for sealing material in the sealing material 5 is preferably 0.80 g / cm ³ or more, and there is no upper limit. The measurement and evaluation of density can be performed by a method based on JIS K7112.

  Although there is no restriction | limiting in the position which provides the sealing material 5, Usually, it provides so that the organic solar cell 6 may be inserted | pinched. This is to protect the organic solar cell 6 reliably. In this embodiment, the sealing material 5 and the sealing material 7 are provided on the front surface and the back surface of the organic solar cell 6, respectively.

[6-6. Organic solar cell (6)]
The organic solar cell 6 is the same as the organic solar cell 230 described above. That is, the organic thin film solar cell module 14 can be manufactured using the organic solar cell 230.

  Only one organic solar cell 6 may be provided for each organic thin-film solar cell module 14, but usually two or more organic solar cells 6 are provided. The specific number of organic solar cells 6 may be set arbitrarily. When a plurality of organic solar cells 6 are provided, the organic solar cells 6 are often provided in an array.

  When a plurality of organic solar cells 6 are provided, usually, the organic solar cells 6 are electrically connected to each other, and electricity generated from the connected group of organic solar cells 6 is taken out from a terminal (not shown). At this time, the organic solar cells are usually connected in series in order to increase the voltage.

  When the organic solar cells 6 are connected to each other as described above, the distance between the organic solar cells 6 is preferably small, and thus the gap between the organic solar cell 6 and the organic solar cell 6 is preferably narrow. This is because the light receiving area of the organic solar cell 6 is widened to increase the amount of light received, and the power generation amount of the organic thin film solar cell module 14 is increased.

[6-7. Encapsulant (7)]
The sealing material 7 is a film similar to the sealing material 5 described above, and the same material as the sealing material 7 can be used in the same manner except that the arrangement position is different. Moreover, since the constituent member on the back side of the organic solar cell 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[6-8. Getter material film (8)]
The getter material film 8 is the same film as the getter material film 4 described above, and the same material as the getter material film 4 can be used as necessary, except for the arrangement position. Moreover, since the constituent member on the back side of the organic solar cell 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[6-9. Gas barrier film (9)]
The gas barrier film 9 is the same film as the gas barrier film 3 described above, and the same material as the gas barrier film 9 can be used as necessary except that the arrangement position is different. Moreover, since the constituent member on the back side of the organic solar cell 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[6-10. Back sheet (10)]
The back sheet 10 is the same film as the weather-resistant protective film 1 described above, and the same material as the weather-resistant protective film 1 can be used in the same manner except that the arrangement position is different. In addition, if the back sheet 10 is difficult to permeate water and oxygen, the back sheet 10 can also function as a gas barrier layer. Moreover, since the constituent member on the back side of the organic solar cell 6 does not necessarily need to transmit visible light, a member that does not transmit visible light can be used.

[6-11. Dimensions]
The organic thin film solar cell module 14 of the present embodiment is usually a thin film member. Thus, by forming the organic thin film solar cell module 14 as a film-like member, the organic thin film solar cell module 14 can be easily installed in a building material, an automobile, an interior, or the like. The organic thin-film solar cell module 14 is light and difficult to break, and thus a highly safe solar cell can be obtained and can be applied to a curved surface, so that it can be used for more applications. Since it is thin and light, it is preferable in terms of distribution such as transportation and storage. Furthermore, since it is in the form of a film, it can be manufactured in a roll-to-roll manner, and the cost can be greatly reduced.

  Although there is no restriction | limiting in the specific dimension of the organic thin film solar cell module 14, The thickness is usually 300 micrometers or more and 3000 micrometers or less.

[6-12. Production method]
Although there is no restriction | limiting in the manufacturing method of the organic thin film solar cell module 14, For example, as a manufacturing method of the solar cell module of the form of FIG. 5, after producing the laminated body shown by FIG. Is mentioned. The organic solar cell of the present embodiment is preferable in that deterioration due to the laminate sealing step is reduced because of excellent heat resistance.

  The laminate shown in FIG. 5 can be produced using a known technique. The method of the laminate sealing step is not particularly limited as long as the effects of the present invention are not impaired. Laminate, thermal laminate, etc. are mentioned. Among them, a laminating method using a photo-curing adhesive having a proven record in organic EL device sealing, a hot melt laminate or a thermal laminate having a proven record in solar cells is preferable, and a hot melt laminate or a thermal laminate is a sheet-like sealing material. It is more preferable at the point which can be used.

  The heating temperature in the laminate sealing step is usually 130 ° C or higher, preferably 140 ° C or higher, and is usually 180 ° C or lower, preferably 170 ° C or lower. The heating time in the laminate sealing step is usually 10 minutes or longer, preferably 20 minutes or longer, and is usually 100 minutes or shorter, preferably 90 minutes or shorter. The pressure in the laminate sealing step is usually 0.001 MPa or more, preferably 0.01 MPa or more, and usually 0.2 MPa or less, preferably 0.1 MPa or less. By setting the pressure within this range, sealing can be performed reliably, and the reduction of the film thickness due to the protrusion of the sealing materials 5 and 7 from the end portion and overpressurization can be suppressed, thereby ensuring dimensional stability. In addition, what connected two or more organic solar cells 6 in series or in parallel can be manufactured similarly to the above.

[6-13. Application]
There is no restriction | limiting in the use of the organic solar cell of this invention, It can use for arbitrary uses. Examples of fields to which organic thin film solar cells are applied include building material solar cells, automotive solar cells, interior solar cells, railroad solar cells, marine solar cells, airplane solar cells, spacecraft solar cells, A solar cell for home appliances, a solar cell for mobile phones, a solar cell for toys, and the like.

The organic solar cell according to the present invention, in particular, the organic thin film solar cell module may be used as it is, or the organic thin film solar cell module may be installed on a substrate and used as a solar cell panel. For example, as schematically shown in FIG. 6, a solar cell panel 13 provided with an organic thin film solar cell module 14 may be prepared on a base material 12 and installed at a place of use. That is, the solar cell panel 13 can be manufactured using the organic thin film solar cell module 14. As a specific example, when a building material plate is used as the base material 12, a solar cell panel can be produced as the solar cell panel 13 by providing the organic thin film solar cell module 14 on the surface of the plate material.

  The substrate 12 is a support member that supports the organic thin film solar cell module 14. Examples of the material for forming the substrate 12 include inorganic materials such as glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluorine. Organic materials such as resin, vinyl chloride, polyethylene, cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate and polynorbornene; paper materials such as paper and synthetic paper; metals such as stainless steel, titanium and aluminum; Examples thereof include composite materials such as those obtained by coating or laminating a surface of a metal such as stainless steel, titanium, and aluminum to impart insulation.

  In addition, 1 type may be used for the material of a base material, and 2 or more types may be used together by arbitrary combinations and a ratio. Moreover, carbon fiber may be included in these organic materials or paper materials to reinforce the mechanical strength. When the example of the base material 12 is given, Alpolic (registered trademark; manufactured by Mitsubishi Plastics) and the like may be mentioned.

  Although there is no restriction | limiting in the shape of the base material 12, Usually, a board | plate material is used. Moreover, what is necessary is just to set the material of the base material 12, a dimension, etc. arbitrarily according to the use environment. This solar cell panel can be installed on the outer wall of a building.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, it cannot be overemphasized that this invention is not limited only to a following example.

<Example 1>
An organic layer in which ITO (thickness: 80 nm), P3HT / PCBM (thickness: 400 nm), and Ag (thickness: 50 nm) are sequentially laminated on a glass substrate (thickness: 0.7 mm) by sputtering, solution coating, and vapor deposition, respectively. Polyester resin (trade name: Toyobo "Byron (registered trademark) 200") that is soluble in general-purpose organic solvents and has a crosslinkable hydroxyl group is dissolved in methyl ethyl ketone in a solar cell element, and an isocyanate curing agent (product) Name: Nippon Polyurethane Industry Co., Ltd. “Coronate HL”) was added and stirred, applied by spin coating, solvent drying at 80 ° C. for 5 minutes, heat curing treatment at 100 ° C. for 30 minutes, and undercoat A layer (thickness 0.2 μm, elastic modulus 2 GPa) was formed.
Further, a silica layer was deposited on the undercoat layer by a plasma CVD method, and a barrier layer (thickness 0.5 μm, elastic modulus 100 GPa) was laminated to obtain an organic solar cell 1.

<Example 2>
The organic solar cell 2 (undercoat layer thickness 0) was used in the same manner as in Example 1 except that the polyester resin of the undercoat layer was an isocyanate crosslinkable polyurethane resin (trade name: Toyo Morton “TM-K51”). 0.2 μm, elastic modulus 800 MPa).

<Example 3>
The polyester resin of the undercoat layer was an organic silicate resin (trade name: Arakawa Chemical “Composeran”), and the heat curing treatment at 100 ° C. × 30 minutes was changed to a UV curing treatment (high pressure mercury lamp (USHIO Inc., model: Except for using UVC-5035 / 1MNLC6-HGO) and irradiating until the total irradiation amount reaches 500 mJ / cm ² ), the organic solar cell 3 (undercoat layer thickness 0.2 μm, elastic) The rate was 10 GPa).

<Example 4>
An organic solar cell 4 was obtained in the same manner as in Example 1 except that the thickness of the undercoat layer was 2.0 μm.

<Example 5>
The undercoat layer is an acrylic resin containing a photopolymerization initiator (trade name: Mitsubishi Rayon “Ray Queen”, which is mainly composed of a blend composition of an acrylic acid ester-based oligomer having a methacryloyl group and an ultraviolet curable acrylic monomer.・ RQ-5005 ”) was diluted with a mixed solvent of ethyl acetate and toluene and applied by spin coating, and the heat curing treatment at 100 ° C. × 30 minutes was changed to a UV curing treatment (high pressure mercury lamp (manufactured by USHIO INC.) , Type: UVC-5035 / 1MNLC6-HGO), and the organic solar cell 5 (undercoat layer thickness) in the same manner as in Example 4 except that irradiation is performed until the total irradiation amount reaches 500 mJ / cm ^2. 2 μm, elastic modulus 4 GPa).

<Example 6>
An acrylic resin (trade name: Mitsubishi Rayon Co., Ltd., “Ray Queen”) containing, as a main component, a blend composition of an acrylic ester-based oligomer having a methacryloyl group and an ultraviolet curable acrylic monomer on the barrier layer. RQ-5005 ") is diluted with a mixed solvent of ethyl acetate / toluene, applied by a spin coating method, dried at 80 ° C. for 5 minutes, and then dried with a high-pressure mercury lamp (USHIO INC., Model: UVC-5035 / 1MNLC6). -HGO), UV irradiation was applied until an integrated dose of 500 mJ / cm ² was reached, and an overcoat layer (thickness 2 μm, elastic modulus 4 GPa) was laminated, as in Example 1. The organic solar cell 6 was obtained.

<Comparative Example 1>
An organic solar cell 7 was obtained in the same manner as in Example 1 except that the undercoat layer was not laminated.

<Weather resistance test>
The weather resistance test was conducted on the organic solar cells of Examples 1, 2, 3, 4 and Comparative Example 1 obtained as described above.
(Test method and results)
Using an ATLAS light resistance tester (CI-4000), 1 SUN (equivalent to 1.5 AM) was irradiated with light at an environmental temperature of 55 ° C. and a relative humidity of 55%. The device efficiency was measured before and after the test, 120 hours and 240 hours after the start, and the device deterioration was evaluated by determining the relative change in efficiency relative to the time before the test. The results are shown in Table 1.

<Dump heat test>
A dump heat test was performed on the organic solar cells of Examples 5 and 6 and Comparative Example 1 obtained as described above.
(Test method and results)
The temperature was maintained at 55 ° C. and a relative humidity of 55% without light irradiation. Element efficiency was measured by measuring the element efficiency 50 hours and 100 hours after the start of the test and by determining the relative change in efficiency relative to before the start of the test. The results are shown in Table 2.

In contrast to Comparative Example 1 in which no undercoat was provided, in Examples 1 to 3, the deterioration was significantly suppressed by providing an undercoat, and in Example 4, the deterioration was further suppressed by increasing the thickness of the undercoat. Has been shown to be.
In the dump heat test, the barrier layer is destroyed by wet heat, and it is thought that the deterioration proceeds due to the penetration of moisture into the organic solar cell. In Comparative Example 1 in which no undercoat was provided, the element deteriorated and short-circuited. In Example 5 with an undercoat, deterioration is significantly suppressed, and in addition, Example 6 with an overcoat is shown to further suppress deterioration.
That is, it is obvious that the present invention has an effect by these examples.

101 Cathode 102 Electron Extraction Layer 103 Active Layer 104 Hole Extraction Layer 105 Anode 106 Base Material (Support for Organic Solar Cell Element)
107 Organic Solar Cell Element 221 Undercoat Layer 222 Barrier Layer 223 Overcoat Layer 224 Adhesive Layer 225 Film Member 230 Organic Solar Cell 1 Weatherproof Protective Film 2 UV Cut Films 3 and 9 Gas Barrier Films 4 and 8 Getter Material Films 5 and 7 Sealing material 6 Organic solar cell 10 Back sheet 12 Base material (support for organic solar cell module)
13 Solar Panel 14 Organic Thin Film Solar Cell Module

Claims (10)

An organic solar cell element comprising an organic solar cell element having at least a pair of electrodes on a substrate and an active layer present between the electrodes, and having a barrier layer on the organic solar cell element via an undercoat layer A manufacturing method comprising:
Have a step, the barrier layer is formed on the undercoat layer on the organic solar cell element is laminated,
The undercoat layer is a film made of an organic polymer composition, the elastic modulus at 23 ° C. is 20 GPa or less, the elastic modulus of the undercoat layer is 1/100 or less with respect to the elastic modulus of the barrier layer, and the thickness of the undercoat layer is Ru der than 20μm below 0.1 [mu] m, the manufacturing method of the organic solar cell.   The method for producing an organic solar cell according to claim 1, wherein an overcoat layer is further laminated on the barrier layer.   Furthermore, the film-like member is laminated | stacked through the contact bonding layer, The manufacturing method of the organic solar cell of Claim 1 or 2 characterized by the above-mentioned. The elastic modulus at 23 ° C. of the undercoat layer is 20 GPa or less, the elastic modulus at 23 ° C. of the overcoat layer is 100 MPa or more, and the elastic modulus of the undercoat layer is 1/10 or more of the elastic modulus of the overcoat layer. It is 2 times or less, The manufacturing method of the organic solar cell of Claim 2 or 3 characterized by the above-mentioned. The material of the undercoat layer includes one or more selected from polyester resins, polyurethane resins, and acrylic resins, and the material of the overcoat layer includes one or more selected from polyester resins, epoxy resins, and acrylic resins. wherein the manufacturing method of the organic solar battery according to any one of claims 2-4. The method for producing an organic solar cell according to any one of claims 1 to 5 , wherein the barrier layer is formed by a vacuum film formation method by any one of vacuum vapor deposition, chemical vapor deposition (CVD), and sputtering, or a combination thereof. Undercoat layer is formed by wet coating method under atmospheric pressure, a method of manufacturing an organic solar battery according to any one of claims 1-6. Overcoat layer is formed by wet coating method under atmospheric pressure, a method of manufacturing an organic solar battery according to any one of claims 2-7. Wherein the substrate is a resin film, a manufacturing method of an organic solar battery according to any one of claims 1-8. The undercoat layer is a thermosetting resin or ultraviolet curable resin, the manufacturing method of the organic solar cell according to any one of claims 1-9.