JP2015167226A - organic thin film solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic thin film solar cell module, having high mechanical strength against an external load, excellent in exterior appearance, having high durability.SOLUTION: The organic thin film solar cell module includes: a support body 3; an organic thin film solar cell element 4; an adhesive layer 5; and an encapsulation base material 6 in this order. The organic thin film solar cell element 4 has a pair of transparent electrodes. The adhesive layer 5 contains a polyolefin resin.

Description

  The present invention relates to an organic thin film solar cell module.

  In recent years, solar cells using solar energy have been actively developed, and in particular, organic thin-film solar cells have been actively developed as a type of next-generation solar cell following silicon solar cells. . As one aspect of the organic thin film solar cell, a see-through solar cell has been studied. Since the see-through type organic solar cell is required to have high light transmittance, it is necessary to devise a member constituting the solar cell, and in particular, it is necessary to examine the light transmittance of the electrode of the organic solar cell. For example, Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2 describe organic solar cells that use grid electrodes or mesh electrodes to ensure light transmission.

JP 2011-205149 A

Solar Energy Material & Solar Cells 114, 214 (2013) ACS Nano vol. 6 7185-7190 (2012)

  In order to realize a see-through type organic solar cell, it is an important issue to improve not only light transmittance but also durability. In particular, since the active layer and the like constituting the organic solar cell is formed of an organic semiconductor compound, it is easily affected by external factors such as water, and if the water enters the active layer or the like, the conversion efficiency of the solar cell is increased. There is a tendency to drop significantly. However, according to the study by the present inventors, when a grid electrode or a mesh electrode as described in Patent Document 1, Non-Patent Document 1 and Non-Patent Document 2 is used, a highly durable organic solar cell is used. It has proven difficult to manufacture. The reason for this is that since both the grid electrode and the mesh electrode have an opening in the electrode itself, moisture can still enter the active layer even if the elements constituting the solar cell are sealed. It is thought that. Moreover, when a grid electrode or a mesh electrode is used, light is not transmitted through the portions other than the openings, and therefore, there is a problem in that the translucency is insufficient and the appearance is impaired. Therefore, the present inventors use a transparent electrode using a metal oxide-containing layer or a thin metal layer instead of the grid electrode or mesh electrode in order to improve durability, light transmittance and appearance. Considered to do. However, according to the study by the present inventors, the metal oxide-containing layer has low flexibility, and the thin metal layer has low mechanical strength. Therefore, when used as an organic solar cell or in the manufacturing process of an organic solar cell. It has been found that when an external load is applied, cracks are generated in the transparent electrode to deteriorate the appearance, and the conversion efficiency may be lowered.

  This invention solves the said problem, and it aims at providing the organic thin film solar cell module which has the high mechanical strength with respect to an external load, and has the high durability which was excellent in the external appearance property.

As a result of intensive studies to solve the above problems, the present inventors have solved the above problems by using an adhesive layer containing a specific resin, and have achieved the present invention. That is, the gist of the present invention is as follows.

[1] An organic thin film solar cell module having a support, an organic thin film solar cell element, an adhesive layer, and a sealing substrate in this order, wherein the organic thin film solar cell element has a pair of transparent electrodes. And the said adhesion layer contains polyolefin resin, The organic thin-film solar cell module characterized by the above-mentioned.
[2] It has a first sealing substrate, a first adhesive layer, a support, an organic thin film solar cell element, a second adhesive layer, and a second sealing substrate in this order. In the organic thin film solar cell module, the organic thin film solar cell element has a pair of transparent electrodes, and the first adhesive layer and the second adhesive layer contain a polyolefin resin. Organic thin-film solar cell module.
[3] In the organic thin-film solar cell element, an end portion of the first adhesive layer and an end portion of the second adhesive layer are bonded together, and the first adhesive layer and the second adhesive layer The organic thin-film solar cell module according to [2], which is covered.
[4] The organic thin film solar cell module according to [2] or [3], wherein the first sealing substrate and the second sealing substrate are glass substrates.
[5] Any one of [2] to [4], wherein a water vapor transmission rate per 50 μm thickness of the first adhesive layer and the second adhesive layer is 20 g / m ² / day or less. The organic thin film solar cell module according to 1.

  According to the present invention, it is possible to provide an organic thin-film solar cell module having high durability with high mechanical strength against an external load and excellent appearance.

It is a cross-sectional schematic diagram showing the layer structure of the organic thin-film solar cell element as one Embodiment of this invention. It is a cross-sectional schematic diagram showing the structure of the organic thin film solar cell module as one Embodiment of this invention. It is a cross-sectional schematic diagram showing the structure of the organic thin film solar cell module as one Embodiment of this invention. It is a cross-sectional schematic diagram showing the layer structure of the organic thin-film solar cell element as one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. The description of the constituent requirements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not specified in these contents unless it exceeds the gist.

<1. Organic thin film solar cell module>
As shown in FIG. 4, the organic thin film solar cell module according to one embodiment of the present invention includes at least a support 3, an organic thin film solar cell element 4, an adhesive layer 5, and a sealing substrate 6. In this order. The organic thin-film solar cell module according to the present invention is not limited to the structure shown in FIG. 4 and may have another layer in addition to the configuration shown in FIG. For example, the organic thin film solar cell module according to the present invention may have an adhesive layer and a sealing substrate also on the support substrate side. That is, as shown in FIG. 2, the organic thin film solar cell module according to the present invention includes at least a first sealing substrate 1, a first adhesive layer 2, a support 3, and an organic thin film solar cell element. 4, the second adhesive layer 5, and the second sealing substrate 6 may be included. In addition, as shown in FIG. 2, when an organic thin-film solar cell has two sealing base materials, each sealing base material is called a 1st sealing base material and a 2nd sealing base material for convenience. Similarly, when the organic thin-film solar cell module has two adhesive layers, the respective adhesive layers are referred to as a first adhesive layer and a second adhesive layer for convenience.

  Hereafter, each structural member which comprises the organic thin film solar cell module shown in FIG. 2 is demonstrated in detail. The organic thin-film solar cell module according to the present invention is preferably a see-through type organic solar cell that has excellent appearance and can be applied to building materials such as windows. The see-through type organic solar cell is an average value of 10% or more of the visible light transmittance defined by JIS R3106 of light incident from the first sealing substrate and transmitted through the second sealing substrate. Means organic solar cells.

<1-1. Sealing substrate (first sealing substrate 1, second sealing substrate 6)>
The first sealing substrate 1 and the second sealing substrate 6 are layers that prevent permeation of water and oxygen. By covering the organic thin film solar cell element 4 described later with the first sealing substrate 1 and the second sealing substrate 6, the organic thin film solar cell element 4 is protected from moisture and oxygen from the outside, It can prevent that the function of the organic thin-film solar cell element 4 deteriorates.

Proof capability required in the first sealing substrate 1 and the second sealing substrate 6, but vary depending on the organic thin-film solar cell element, per day of the unit area (1 m ²⁾ steam Transmittance is usually 1x
It is preferably 10 ⁻¹ g / m ² / day or less, and the lower limit is not limited. Further, the degree of oxygen permeability required for the first sealing substrate 1 and the second sealing substrate 6 varies depending on the organic thin film solar cell element, but the unit area (1 m ² ). It is preferable that the oxygen permeability per day is usually 1 × 10 ⁻¹ cc / m ² / day / atm or less, and the lower limit is not limited.

  The 1st sealing base material 1 and the 2nd sealing base material 6 have translucency required in order to produce a see-through type organic thin film solar cell module. In the present invention, having translucency means that the average light transmittance in a visible light wavelength region (360 nm to 830 nm) is 40% or more. In order to improve the conversion efficiency of the solar cell module, the average light transmittance of the first sealing substrate 1 and the second sealing substrate is preferably 70% or more. The average light transmittance can be measured with an ordinary spectrophotometer by the method described in JIS R3106.

  Since the organic thin-film solar power module is often heated by receiving light, it is preferable that the first sealing substrate 1 and the second sealing substrate 6 have heat resistance. From this viewpoint, the melting points of the first sealing substrate 1 and the second sealing substrate 6 are usually 100 ° C. or higher and 350 ° C. or lower. However, this is not the case when the first sealing substrate 1 or the second sealing substrate 6 is made of an inorganic material such as glass.

  The specific structure of the 1st sealing base material 1 and the 2nd sealing base material 6 is arbitrary as long as an organic thin film solar cell element can be protected from a water | moisture content or oxygen. However, the manufacturing cost tends to increase as the amount of water vapor or oxygen that can permeate the first sealing substrate 1 and the second sealing substrate 6 tends to increase. It is preferable to use an appropriate one in consideration of the above.

  Especially, as the 1st sealing substrate 1 and the 2nd sealing substrate 6, the lamination of a glass substrate, a resin layer, and a metal oxide layer, or lamination of a resin layer and a metal layer is mentioned, for example. It is done. Further, it may be a laminate of a resin layer, a metal oxide layer, and a metal layer.

As the glass substrate, for example, Corning Corporation 1737, Asahi Glass Co., Ltd. Leofrex, Avant Straight Corporation NA32SG can be used. Although there is no particular limitation on the thickness of the glass substrate, it is usually 0.3 mm or more, preferably 0.4 mm or more, in order to ensure handling at the time of processing, construction and mechanical strength at the time of installation, It is especially preferable that it is 0.5 mm or more. On the other hand, the thickness of the glass substrate is usually 2 mm or less, preferably 1.5 mm or less, and preferably 1 mm or less in order to take advantage of the light weight of the organic solar cell that can be formed on the film substrate. Is particularly preferred.

  Examples of the resin for the resin layer include polyesters such as polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), and polyamides such as nylon 6. PEN is preferable in consideration of PET and heat resistance because of price. The thickness of the resin layer is usually 1 μm or more, preferably 2 μm or more, more preferably 5 μm or more, and usually 200 μm or less, preferably 50 μm or less, more preferably 30 μm or less. It is preferable from the point of the softness | flexibility of a film by being below the said upper limit. It is preferable at the point of ensuring film strength by being more than the said minimum.

  Examples of the metal oxide of the metal oxide layer include SiOx and AlOx. In order to easily ensure high barrier properties, SiOx is preferable.

  Although there is no special restriction | limiting in the thickness of a metal oxide layer, in order to reduce a defect, it is 5 nm or more normally, it is preferable that it is 10 nm or more, and it is especially preferable that it is 20 nm or more. On the other hand, in order to reduce cost and ensure translucency, the thickness of the metal oxide layer is usually 5 μm or less, preferably 2 μm or less, and particularly preferably 0.5 μm or less.

  Examples of the metal of the metal layer include gold, silver, copper, aluminum, and stainless steel, and aluminum is preferable for cost reasons.

  The thickness of the metal layer is not particularly limited, but is usually 1 nm or more, preferably 2 nm or more, and particularly preferably 5 nm or more in order to ensure barrier properties and reduce defects. On the other hand, in order to ensure translucency, the thickness of the metal layer is usually 100 nm or less, preferably 50 nm or less, and particularly preferably 20 nm or less.

  Note that the first sealing substrate 1 and the second sealing substrate 6 may have the same configuration or different configurations.

  Among the above, in the present invention, both the first sealing substrate 1 and the second sealing substrate 6 are particularly preferably glass substrates. Since the glass substrate has a very low water vapor transmission rate as compared with a laminate of a metal layer or / and a metal oxide layer and a resin such as PEN or PET, the organic thin film solar cell element 4 is hardly deteriorated. Tend. Furthermore, since the glass substrate has higher adhesiveness with an adhesive layer containing a polyolefin-based resin, which will be described later, as compared with a resin layer such as PEN or PET, the first sealing substrate 1 or the second sealing substrate 1 If the sealing substrate 6 is a glass substrate, it is possible to prevent moisture and oxygen from entering the organic thin film solar cell element 4 from the interface with each adhesive layer adjacent to each sealing substrate as much as possible. Moreover, deterioration of the organic thin film solar cell element 4 can be suppressed. Further, if the first sealing substrate 1 and the second sealing substrate 6 are both glass substrates, not only the entire module has a symmetrical structure but also the substrate itself has high rigidity. Therefore, the entire module is less likely to warp, and an organic thin film solar cell module having high durability can be provided.

In addition, when the organic thin-film solar cell module is installed outdoors, that is, in a place directly exposed to wind and rain or sunlight, the module outermost layer is required to have high weather resistance. In general, since the weather resistance of a resin such as PEN or PET is low, a protective layer made of a special resin having weather resistance, waterproofness and the like is required on the resin. The module outermost layer being a glass substrate is advantageous in applications that require such weather resistance because the glass itself has high weather resistance.
From the above points, in the present invention, the first sealing substrate 1 and / or the second sealing substrate 6 is a glass substrate, thereby providing an organic thin film solar cell module having high durability. It becomes possible.

  When the 1st sealing base material 1 or / and the 2nd sealing base material 6 makes a part of a support body or building materials, it is preferable that mechanical strength is large, such as glass by which the tempering process was performed.

  Moreover, the 1st sealing base material 1 or / and the 2nd sealing base material 6 may have the scattering prevention film, the ultraviolet-ray cut film, the heat shielding film, etc. bonded on the outer side.

<1-2. Adhesive layer (first adhesive layer 2, second adhesive layer 5)>
The 1st contact bonding layer 2 is a layer for bonding the 1st sealing base material 1 and the support body 3 by which the organic thin-film solar cell element 4 is arrange | positioned. The second adhesive layer 5 is a layer for bonding the second sealing substrate 6 and the organic thin film solar cell element 4 together. The first adhesive layer 2 and the second adhesive layer 5 each contain a polyolefin resin.

  Examples of the polyolefin resin in the present invention include homopolymers of olefins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, or random or block copolymers of two or more of these olefins. Refers to a high molecular compound having a backbone polymer. The polyolefin resin in the present invention may be a modified polyolefin obtained by graft polymerization of an acid anhydride, an acrylate, an aromatic vinyl monomer, an unsaturated carboxylic acid anhydride, or the like.

  Specific examples of these polyolefin resins include homopolymers of olefins such as polyethylene, polypropylene, and polybutylene, ethylene / α-olefin copolymers such as ethylene-butene copolymers and ethylene-propylene copolymers, or These graft | denatured modified bodies etc. are mentioned. Among these, from the viewpoints of heat resistance, transparency, flexibility, process stability resistance, and the like, a resin composition containing an ethylene / α-olefin copolymer and a graft modified product thereof is preferable.

The molecular weight of the polyolefin-based resin is not particularly limited, but the weight average molecular weight (Mw) is preferably 7 × 10 ⁴ or more, more preferably 1.5 × 10 ⁵ or more, It is preferably 3.0 × 10 ⁵ or less, and more preferably 2.5 × 10 ⁵ or less. If polyolefin resin is the said range, appropriate heat resistance and a softness | flexibility can be ensured.

  The following effects can be expected when the first adhesive layer 2 and the second adhesive layer 5 contain a polyolefin resin.

  The adhesive layer containing a polyolefin resin has a lower water vapor transmission rate than an adhesive layer made of an ethylene-vinyl acetate copolymer resin. Therefore, even if oxygen or moisture passes through the first sealing substrate 1 and the second sealing substrate 6, the organic thin film solar cell element is formed by the first adhesive layer 2 and the second adhesive layer 5. It is possible to prevent moisture and oxygen from entering 4 and to improve the durability of the organic thin film solar cell module.

  Further, since the polyolefin-based resin is made of a hydrophobic material, the water content of the resin is small as compared with ethylene-vinyl acetate copolymer resin, epoxy resin, and the like containing a hydrophilic group. For this reason, the damage to the organic thin film solar cell element 4 by the trace amount water | moisture content which the 1st adhesive layer 2 and the 2nd adhesive layer 5 bring into the organic thin film solar cell element 4 can be reduced. Moreover, since there is little generation | occurrence | production of haze (white turbidity) in a contact bonding layer, it can prevent that an external appearance property falls.

  Furthermore, the adhesive layer containing a polyolefin resin has a low elasticity modulus after bonding as compared with a curable ethylene-vinyl acetate copolymer, an epoxy resin, and the like, and has an appropriate flexibility. Having appropriate flexibility is important for the purpose of protecting the organic thin-film solar cell which is a laminate of thin films. In general, the mechanical strength of each layer constituting the organic thin-film solar cell and the adhesive strength between the layers are weak, and therefore, cracks in the layers or delaminations often occur due to external pressing or bending. Therefore, the use of an adhesive layer having appropriate flexibility is equivalent to providing a buffer layer against this stimulus, and can protect the organic solar cell from mechanical stimulus.

  This protective effect by flexibility is particularly important in a see-through type organic thin film solar cell module having translucency. In the present invention, in the see-through type organic thin film solar cell module, a transparent electrode is used as an electrode constituting the organic thin film solar cell element 4 as described later. As a structure of a transparent electrode, transparent conductive films, such as a metal oxide content layer, are mentioned so that it may mention later. The second adhesive layer 5 is often in contact with such a transparent electrode. However, since the metal oxide-containing layer is generally low in flexibility, it is mechanically affected by the residual stress after film formation. The transparent electrode is very vulnerable to cracks, and cracks are generated in the transparent electrode due to minute stimuli, and cracks are similarly generated in the transparent electrode due to external loads other than during film formation. In addition, even when the transparent electrode has a laminated structure of a transparent conductive film and a metal layer, it is necessary to form the metal layer as thin as possible in order to ensure translucency. However, such a thin metal layer, like the metal oxide layer, is cracked by mechanical stimulation or an external load. As described above, the module in which the crack is generated deteriorates the appearance, and can be a particularly serious problem in the case of a see-through type organic thin-film solar cell module that requires design. Moreover, not only the appearance is impaired, but also the power generation characteristics as a solar cell are deteriorated. When the adhesive layer has flexibility, that is, when the elastic modulus is small, the adhesive layer can absorb the energy of external stimulation, and the energy propagated to the transparent electrode layer can be reduced. Therefore, by using a polyolefin-based resin having a low elastic modulus for the adhesive layer, the transparent electrode can be prevented from being damaged by an external load, and thus the appearance of the organic thin film solar cell module can be prevented from being damaged. Furthermore, the organic thin film solar cell element can be prevented from being damaged.

  Furthermore, since the polyolefin resin used in the present invention often does not require an additional heating step (post-curing step) after the bonding step to improve the adhesion, avoid lowering device efficiency due to high temperature and long heating. Moreover, productivity can be improved.

  In addition, although there is no special restriction | limiting in the ratio for which the polyolefin resin accounts in each contact bonding layer, in order to improve adhesiveness, heat resistance, and transparency more, the ratio for which the polyolefin resin accounts in each contact bonding layer, It is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 98% by mass or more with respect to the total amount of the adhesive layer. The upper limit is not particularly limited.

  It is preferable that the 1st contact bonding layer 2 and the 2nd contact bonding layer 5 have translucency required in order to produce a see-through type organic thin film solar cell module. Although there is no particular limitation on the range of translucency, in order to improve the conversion efficiency of the solar cell module, the average light transmittance of the first adhesive layer 2 and the second adhesive layer 5 is 70% or more. Preferably there is. The average light transmittance can be measured using a normal spectrophotometer by the method described in JIS R3106 as in the case of the sealing substrate 1 and the sealing substrate 6.

As long as the first adhesive layer 2 and the second adhesive layer 5 do not impair the effects of the present invention, in addition to the polyolefin resin, an antioxidant, a metal deactivator, a phosphorus processing stabilizer, an ultraviolet absorber, Stabilizers such as UV stabilizers, optical brighteners, metal soaps, antacid adsorbents, or crosslinking agents, chain transfer agents, nucleating agents, lubricants, plasticizers, fillers, reinforcing materials, pigments, dyes, flame retardants, An additive such as an antistatic agent may be contained.

  Examples of additives used include hindered phenolic antioxidants (eg, Adeka AO-20, BASF Irganox 1010), UV absorbers Adeka LA-20, UV stabilizers, hindered amines. System antioxidants (for example, LA-52 manufactured by Adeka) and the like. Examples of metal deactivators include Irganox MD1024 manufactured by BASF, and examples of flame retardants include FP-600 manufactured by Adeka. Moreover, a silane coupling agent is mentioned as a crosslinking agent for improving adhesiveness with glass, a film, etc.

  The tensile shear bond strength of the first adhesive layer 2 to the first sealing substrate 1 is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and 1 MPa or more. Particularly preferred. Similarly, the tensile shear bond strength of the second adhesive layer 5 to the second sealing substrate 6 is preferably 0.1 MPa or more, more preferably 0.5 MPa or more, and 1 MPa or more. It is particularly preferred. The tensile shear bond strength can be measured by the method described in JISK6850.

The water vapor permeability per 50 μm thickness of the first adhesive layer 2 and the second adhesive layer 5 is 20 g / m ² / day or less in order to prevent moisture from entering the organic thin film solar cell element. It is preferably 10 g / m ² / day or less, more preferably 5 g / m ² / day or less, and there is no particular lower limit. The water vapor permeability of the first adhesive layer 2 and the second adhesive layer 5 can be measured by a differential pressure method (such as DELTAPERRM). In addition, the water vapor transmission rate per 50 μm film thickness means the water vapor transmission rate when converted per 50 μm film thickness, and the water vapor transmission amount is inversely proportional to the thickness of the adhesive layer. Can be calculated.

Water vapor transmission rate per 50 μm film thickness (g / m ² / day) = Measured value of water vapor transmission rate (g / m
m ² / day) × Adhesive layer thickness used for measurement (μm) ÷ 50 (μm)

The oxygen permeability per 50 μm thickness of the first adhesive layer 2 and the second adhesive layer 5 is 200 cc / m ² / day / atm in order to prevent oxygen from entering the organic thin film solar cell element.
Is preferably 100 cc / m ² / day / atm or less, particularly preferably 50 cc / m ² / day / atm or less, and there is no particular lower limit. Note that the oxygen permeability of the first adhesive layer 2 and the second adhesive layer 5 can be measured with an oxygen transmission meter (such as OX-TRAN Model 2/61). The oxygen permeability per 50 μm film thickness means the oxygen permeability when converted per 50 μm film thickness, and the oxygen permeation amount is inversely proportional to the thickness of the adhesive layer. Can be calculated.

Oxygen permeability per film thickness of 50 μm (cc / m ² / day / atm) = Measured value of oxygen permeability (cc / m ² / day / atm) × Thickness of adhesive layer used for measurement (μm) ÷ 50 ( μm)

  Moreover, although there is no special restriction | limiting in the thickness of the 1st contact bonding layer 2 and the 2nd contact bonding layer 5, Usually, it is 2 micrometers or more and is 700 micrometers or less. In addition, in order to fill a step such as a support or a current collector or prevent a reduction in handling properties during the bonding process, it is preferably 10 μm or more, particularly preferably 50 μm or more, In order to prevent water vapor intrusion from the end face of the layer, the thickness is preferably 500 μm or less, and particularly preferably 400 μm or less.

In addition, as the 1st contact bonding layer 2 and / or the 2nd contact bonding layer 5, you may use the commercially available adhesive sheet containing polyolefin resin. For example, PROCELLER (registered trademark) manufactured by Mitsubishi Plastics, Inc. may be mentioned.

  2 shows a state in which the first adhesive layer 2 and the second adhesive layer 5 are laminated so as to sandwich the support 3 and the organic thin film solar cell element 4, but the present invention is not limited thereto. The organic thin film solar cell module according to the above is not limited to this configuration.

  For example, as shown in FIG. 3, in the cross section of the organic thin film solar cell module, the end of the first adhesive layer 2 and the end of the second adhesive layer 5 are bonded together, and the organic thin film solar The battery element 4 is preferably covered with the first adhesive layer 2 and the second adhesive layer 5. In the case of such a configuration, since the end portion of the organic thin film solar cell element 4 is also covered with the first adhesive layer 2 and the second adhesive layer 5, the end side of the organic thin film solar cell element Intrusion of moisture, oxygen, etc. can be prevented. Furthermore, since the first adhesive layer 2 and the second adhesive layer 5 are directly bonded, the interface between the first adhesive layer 2 and the support 3 and the second adhesive layer 5 and the organic thin film Film peeling is less likely to occur at the interface of the solar cell element 4, and the adhesion between the members is improved. Thereby, even if an organic thin film solar cell module is used in an external environment for a long time, degradation of an element can be suppressed and an organic thin film solar cell module with high durability can be provided. In addition, the edge part of the said 1st contact bonding layer 2 and the edge part of the said 2nd contact bonding layer 5 are bonded together, and the said organic thin film solar cell element 4 is the said 1st contact bonding layer 2 and the said 2nd contact | adhesion. In order to improve the prevention of gas component intrusion from the end portion of the organic thin film solar cell module and to secure the adhesive strength, the first adhesive layer 2 and the second adhesive layer 2 are covered with the adhesive layer 5. 2 mm or more is preferable and the width | variety of the area | region (Hereinafter, it may be called the bonding area | region with the 1st adhesive layer 2 and the 2nd adhesive layer 5) where the adhesive layer 5 of this is bonded is 5 mm or more. It is more preferable that it is 10 mm or more. On the other hand, in order to ensure an effective power generation area per module panel area, the width of the bonding region between the first adhesive layer 2 and the second adhesive layer 5 is preferably 100 mm or less, and is 50 mm or less. More preferably, it is particularly preferably 30 mm or less. In addition, in this invention, the width | variety of the bonding area | region with the 1st contact bonding layer 2 and the 2nd contact bonding layer 5 is between the edge part of the organic thin-film solar cell element 4 and the edge part of the support body 3 in FIG. Means the width of the bonding region between the first adhesive layer 2 and the second adhesive layer 5.

  Moreover, although it is not necessarily limited, in order to improve the external appearance property of an organic thin film solar cell module, the edge part of the 1st sealing base material 1 and the edge part of the 1st contact bonding layer 2 must have gathered. Is preferred. For the same reason, it is preferable that the end of the second sealing substrate 6 and the end of the second adhesive layer 5 are also aligned. Furthermore, although not necessarily limited, it is preferable that the ends of the first adhesive layer 2 and the second adhesive layer 5 are also aligned.

<1-3. Organic Thin Film Solar Cell Element 4>
In the present invention, the organic thin film solar cell element has at least a pair of transparent electrodes. Hereinafter, with reference to FIG. 1, one Embodiment of an organic thin-film solar cell element is described. As shown in FIG. 1, an organic thin-film solar cell element according to an embodiment of the present invention has a lower electrode 101, a lower buffer layer 102, an organic photoelectric conversion layer 103 (a p-type semiconductor compound and an n-type) on a support 3. A layer including a semiconductor material), an upper buffer layer 104, and an upper electrode 105 are sequentially formed. In FIG. 1, the lower electrode 101 exists above the upper electrode 105. In this specification, the upper electrode and the lower electrode refer to the upper electrode and the lower electrode, respectively, when the support 3 is the bottom. The electrode laminated on the base material 3 is referred to as a lower electrode. The lower electrode 101 and the upper electrode 105 are collectively referred to as a pair of electrodes.

<1-3-1. Pair of electrodes (lower electrode 101, upper electrode 105)>
The lower electrode 101 and the upper electrode 105 have a function of collecting holes and electrons generated by light absorption. Specifically, one of the pair of electrodes is suitable for collecting holes (sometimes referred to as an anode), and the other electrode is suitable for collecting electrons (hereinafter referred to as a cathode). In some cases). Therefore, when the lower electrode 101 is an anode, the upper electrode 105 is a cathode, and when the lower electrode 101 is a cathode, the upper electrode 105 is an anode.

  The lower electrode 101 and the upper electrode 105 are transparent electrodes in order to produce a see-through type organic thin film solar cell module. In addition, the transparent electrode in this invention is an electrode comprised by having a transparent conductive film. In the present invention, the transparent conductive film means a film having conductivity and having a visible light transmittance of 40% or more. Note that the visible light transmittance of the transparent conductive film is preferably 70% or more in order to cause more light to reach the photoelectric conversion layer. The visible light transmittance can be measured by a method defined in JIS R3106.

  Examples of the material for the transparent conductive film included in the transparent electrode include conductive metal oxides such as nickel oxide, tin oxide, indium oxide, indium tin oxide (ITO), indium zinc oxide (IZO), titanium oxide, and zinc oxide. A content layer is mentioned. The transparent electrode may be a single layer or a stacked layer. For example, the transparent electrode may be formed by laminating a thin film layer made of a metal such as gold, platinum, silver, aluminum, chromium, cobalt, or an alloy thereof in addition to the transparent conductive film. Further, a metal oxide-containing layer or metal layer in which a conductive polymer material doped with iodine or the like in polypyrrole or polyaniline or the like is used as a transparent electrode. You can also. The electrode in the present invention may have a laminated structure of two or more layers made of these materials. Among these, from the viewpoint of high translucency, low sheet resistance, film forming processability, etc., a single layer of indium tin oxide (ITO) or indium zinc oxide (IZO), or indium tin oxide (ITO) or indium zinc oxide A laminate of (IZO) and a metal is preferred.

  Of the transparent electrodes, it is preferable to use a transparent electrode having a work function larger than that of the cathode for the anode and a transparent electrode having a work function smaller than that of the anode for the cathode.

  As described above, the transparent electrode may be a single layer or a stacked layer. The total film thickness of the transparent electrode is not particularly limited, but is usually 5 nm or more, preferably 10 nm or more, and more preferably 20 nm or more. On the other hand, it is usually 2 μm or less, preferably 1 μm or less, and more preferably 500 nm or less. When the film thickness is 5 nm or more, the sheet resistance is suppressed, and when the film thickness is 2 μm or less, light can be efficiently converted into electricity without lowering the light transmittance. The film thickness must be controlled in a region where both light transmittance and sheet resistance can be achieved.

  The sheet resistance of the transparent electrode is not particularly limited, but is usually 0.1Ω / □ or more, on the other hand, 1000Ω / □ or less, preferably 500Ω / □ or less, more preferably 100Ω / □ or less.

  Examples of the method for forming the transparent electrode 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.

After laminating the transparent electrode, the organic thin film solar cell element is usually heat-treated 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. (This process may be referred to as an annealing process). It is preferable to perform the annealing process at a temperature of 50 ° C. or higher because an effect of improving the adhesion between the layers of the organic thin film solar cell element can be obtained. By improving the adhesion between the layers, the thermal stability and durability of the organic thin film solar cell element can be improved. It is preferable to set the temperature of the annealing treatment step to 300 ° C. or lower because the organic compound in the organic photoelectric conversion layer is less likely to be thermally decomposed. In the annealing treatment step, stepwise heating may be performed within the above temperature range.

<1-3-2. Lower buffer layer (102), upper buffer layer (104)>
The lower buffer layer 102 and the upper buffer layer 104 each have a function of improving the electron extraction efficiency from the organic photoelectric conversion layer 103 to the cathode or the hole extraction efficiency from the organic photoelectric conversion layer 103 to the anode. The buffer layer having a function of improving the electron extraction efficiency from the organic photoelectric conversion layer 103 to the cathode is an electron extraction layer, and the buffer layer having a function of improving the electron extraction efficiency from the organic photoelectric conversion layer 103 to the cathode is a hole. This is called a take-out layer. Note that the lower buffer layer 102 and the upper buffer layer 104 are not essential components, and the organic thin-film solar cell element 4 may not have the lower buffer layer 102 and the upper buffer layer 104. Moreover, you may have only any one layer.

  The lower buffer layer 102 and the upper buffer layer 104 may be either an electron extraction layer or a hole extraction layer, but when the lower electrode 101 is a cathode and the upper electrode 105 is an anode, the lower buffer layer 102 is an electron extraction layer. The upper buffer layer 104 is a hole extraction layer. On the other hand, when the lower electrode 101 is an anode and the upper electrode 105 is a cathode, the lower buffer layer 102 is a hole extraction layer and the upper buffer layer 104 is an electron extraction layer.

<1-3-2-1. Electron extraction layer>
The material of the electron extraction layer is not particularly limited as long as it is a material that improves the efficiency of extracting electrons from the organic photoelectric conversion layer to the cathode, 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). Although the operation mechanism of such a material is unknown, it is conceivable to reduce the work function of the cathode when combined with a cathode made of Al or the like and increase the voltage applied to the solar cell element.

  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 thickness of the electron extraction layer is usually 0.1 nm or more, preferably 1 nm or more, more preferably 10 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 is 0.1 nm or more, it functions as a buffer material. When the film thickness of the electron extraction layer is 400 nm or less, electrons are easily extracted and the photoelectric conversion efficiency is improved. Can improve.

  The LUMO energy level of the material of the electron extraction layer 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 for the electron extraction layer is −1.9 eV or less because charge transfer can be promoted. It is preferable that the LUMO energy level of the material for the electron extraction layer is −4.0 eV or more in terms of preventing reverse electron transfer to the n-type semiconductor material.

  The HOMO energy level of the material for the electron extraction layer 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 for the electron extraction layer 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, a cyclic voltammogram measurement method may be mentioned. 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 is an organic compound, the glass transition temperature (hereinafter sometimes referred to as Tg) of this compound as measured by the 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. Moreover, it is preferable that the material of an electron taking-out layer is a thing by which the glass transition temperature by DSC method is not observed below 30 degreeC or more and less than 55 degree | times.

  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 thermophysical property measurement method (differential scanning calorimetry method) 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.

There is no restriction | limiting in the formation method of an electronic taking-out layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. Further, for example, when a material soluble in a solvent is used, it can be formed by a wet coating method such as spin coating or inkjet.
When the electron extraction layer 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.
Specifically, for example, when an alkali metal salt is used as a material for the electron extraction layer, the electron extraction layer can be formed by using a vacuum film formation method such as vacuum deposition or sputtering. Especially, it is desirable to form an electron taking-out layer by vacuum vapor deposition by resistance heating. By using vacuum deposition, damage to other layers such as an organic photoelectric conversion layer can be reduced.

  On the other hand, for metal oxides of n-type semiconductors, for example, when zinc oxide ZnO is used as the material for the electron extraction layer, a vacuum film formation method such as sputtering can be used. It is desirable to form the extraction layer. 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), an electron extraction layer composed of zinc oxide can be formed. In this case, 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 is too thin, the effect of improving the electron extraction efficiency is not sufficient, and if it is too thick, the electron extraction layer tends to deteriorate the characteristics of the device by acting as a series resistance component.

<1-3-2-2. Hole extraction layer>
The material for the hole extraction layer is not particularly limited as long as it is a material capable of improving the efficiency of extracting holes from the organic photoelectric conversion layer to the anode. 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 film thickness of the hole extraction layer is usually 0.1 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 is 0.1 nm or more, it functions as a buffer material. When the film thickness of the hole extraction layer is 400 nm or less, holes are easily extracted, Conversion efficiency can be improved.

There is no restriction | limiting in the formation method of a positive hole taking-out layer. For example, when a material having sublimation property is used, it can be formed by a vacuum deposition method or the like. For example, when a material soluble in a solvent is used, it can be formed by a wet coating method such as a spin coating method or an ink jet method. When a semiconductor material is used for the hole extraction layer, 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 photoelectric conversion layer described later.
Especially, when using PEDOT: PSS as a material of a hole taking-out layer, it is preferable to form a hole taking-out layer by the method of apply | coating a dispersion liquid. Examples of the dispersion of PEDOT: PSS include CLEVIOSTM series manufactured by Heraeus, ORGACONTM series manufactured by Agfa, and the like.

  When the hole extraction layer 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.

<1-3-3. Organic photoelectric conversion layer 103>
The organic photoelectric conversion layer 103 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 thin-film solar cell element receives light, the light is absorbed by the organic photoelectric conversion layer, 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 electrode.

  An organic compound is preferably used for the material of the organic photoelectric conversion layer 103 because it can be formed by a simple coating process. The layer structure of the organic photoelectric conversion layer 103 includes a thin film stack type in which a p-type semiconductor compound layer and an n-type semiconductor compound layer are stacked, and a bulk heterojunction type having a layer in which a p-type semiconductor compound and an n-type semiconductor compound are mixed. , A p-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.

  Examples of the p-type semiconductor compound include a low molecular organic compound or a high molecular organic compound, and examples of the n-type semiconductor compound include fullerene derivatives. Examples of the p-type semiconductor compound and the n-type semiconductor compound include compounds described in Solar Energy Materials & Solar Cells 96 (2012) 155-159, International Publication No. 2011-016430, or Japanese Patent Application Laid-Open No. 2012-191194.

  The film thickness of the organic photoelectric conversion layer 103 is not particularly limited, but is usually 10 nm or more, preferably 50 nm or more, and is usually 500 nm or less, preferably 400 nm or less, more preferably 300 nm or less. It is preferable that the film thickness of the organic photoelectric conversion layer 103 is 10 nm or more because power generation efficiency can be ensured by light absorption of a certain level or more, and the uniformity of the film is maintained and short-circuiting is unlikely to occur. Moreover, the thickness of the organic photoelectric conversion layer being 500 nm or less means that appropriate translucency can be ensured, that the internal resistance becomes small, and that the diffusion of charges is good without the electrodes being too far apart. ,preferable.

Although there is no restriction | limiting in particular as a preparation method of the organic photoelectric converting layer 103, The application | 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, roll brush method, spray coating method, air knife coating method, wire barber coating method, Examples include the pipe doctor method, the impregnation / coating method, and the curtain coating 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.
The organic photoelectric conversion layer 103 is preferably manufactured by roll-to-roll, and in that case, it is preferably formed by a coating method.

<1-3-4. Photoelectric conversion characteristics>
The photoelectric conversion characteristics of the organic thin film solar cell element 4 can be obtained as follows. The organic thin-film solar cell element is irradiated with AM1.5G light with a solar simulator at an irradiation intensity of 100 mW / cm ² to measure current-voltage characteristics. 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.
The photoelectric conversion efficiency of the organic thin film solar cell element is not particularly limited, but is usually 1% or more, preferably 1.5% or more, and more preferably 2% or more. On the other hand, there is no particular limitation on the upper limit, and the higher the better.

<1-4. Support 3>
The support 3 is a member for holding and forming the organic thin film photoelectric conversion element 4, and the type thereof is not particularly limited as long as it has the function, but the first sealing substrate 1 and the second sealing It is preferable to have translucency similarly to the substrate 6. If the 1st sealing base material 1, the support body 3, and the 2nd sealing base material 6 have translucency, it can be set as the see-through type organic thin film solar cell module excellent in the external appearance property. .

  The material constituting the support 3 is not particularly limited as long as the effects of the present invention are not significantly impaired. Preferred examples include inorganic materials such as quartz, glass, sapphire, and titania; polyethylene terephthalate, polyethylene naphthalate, poly Ethersulfone, polyimide, nylon, polystyrene, polyvinyl alcohol, ethylene vinyl alcohol copolymer, fluororesin film, polyolefin such as vinyl chloride or polyethylene; cellulose, polyvinylidene chloride, aramid, polyphenylene sulfide, polyurethane, polycarbonate, polyarylate, poly Organic material such as norbornene or epoxy resin; paper material such as paper or synthetic paper; surface or coating to give insulation to metal such as stainless steel, titanium or aluminum And the like composite materials such as those that. In the case of a flexible film-like substrate having flexibility, an organic material, a paper material, and a composite material are preferable, an organic material and a composite material are more preferable, and an organic material is particularly preferable.

  Moreover, although there is no restriction | limiting in the film thickness of the support body 3, it is 5 micrometers or more normally, 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. The film thickness of the support 3 is preferably 5 μm or more because the possibility that the strength of the organic electronic device is insufficient is reduced. It is preferable that the thickness of the support 3 is 20 mm or less because the cost is suppressed and the weight does not increase.

<1-5. Other layers>
As described above, the organic thin film solar cell module according to the present embodiment includes the first sealing substrate 1, the first adhesive layer 2, the support 3, the organic thin film solar cell element 4, the second adhesive layer 5, Although it has the 2nd sealing base material 6 in this order, you may have another layer. Examples of other layers include a getter material layer and an ultraviolet cut layer.

A getter material layer is a layer having a function of absorbing moisture and / or oxygen. The position where the getter material layer is provided is arbitrary. For example, the getter material layer can be provided between the first adhesive layer 2 and the support 3 and between the organic thin film solar cell element 4 and the second adhesive layer 5. Moreover, you may provide in both of these. In the present invention, even if a getter material layer is not provided, it has a sufficiently high barrier property against moisture and oxygen. However, if a getter material layer is provided, for example, moisture can be passed through each member. Even if oxygen or oxygen enters the organic thin film solar cell element 4 side, moisture and oxygen can be captured by the getter material layer, so that the organic thin film solar cell element can be prevented from deteriorating. Moreover, it is preferable that a getter material layer has the translucency required in order to produce a see-through type organic thin-film solar cell module.

The degree of water absorption ability of the getter material layer 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, the oxygen absorption capacity of the getter material layer is usually 10 μl / cm ² or more, and although there is no upper limit, it is usually 1 ml / cm ² or less.

  Furthermore, since organic thin film solar cells are often heated by receiving light, it is preferable that the getter material layer also has heat resistance. From this viewpoint, the melting point of the constituent material of the getter material layer is usually 100 ° C. or higher and 350 ° C. or lower.

  The material constituting the getter material layer 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 (manufactured by Futaba Electronics Co., Ltd.) and moist catch (manufactured by Kyodo Printing Co., Ltd.).

  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.

The getter material layer may be formed of one type of material or may be formed of two or more types of materials. Further, the getter material layer may be a single layer or a laminate of two or more layers.
Although the thickness of a getter material layer is not specifically limited, Usually, they are 5 micrometers or more and 200 micrometers or less.

  The ultraviolet cut layer is a layer that prevents transmission of ultraviolet rays. By providing a UV cut layer on the light receiving portion of the organic thin film solar cell module and covering the light receiving surface of the organic thin film solar cell module with the UV cut layer, the organic thin film solar cell element and the sealing substrate are protected from ultraviolet rays. It is possible to prevent the power generation capacity from being lowered.

  The degree of the ability to suppress the transmission of ultraviolet rays required for the ultraviolet cut layer is such that the transmittance of ultraviolet rays (for example, wavelength 300 nm) is preferably 50% or less, and there is no limit on the lower limit. Moreover, it is preferable that a ultraviolet-ray cut layer permeate | transmits visible light from a viewpoint which does not prevent the light absorption of an organic thin-film solar cell element. For example, the transmittance of visible light (wavelength 360 to 830 nm) is preferably 80% or more, and the upper limit is not limited.

Further, since the organic thin film solar cell module is often heated by receiving light, it is preferable that the ultraviolet cut layer also has heat resistance. From this viewpoint, the melting point of the constituent material of the ultraviolet cut layer is usually 100 ° C. or higher and 350 ° C. or lower.
Moreover, it is preferable that an ultraviolet cut layer has a high softness | flexibility, adhesiveness with an adjacent film is favorable, and can cut water vapor | steam and oxygen.

  The material constituting the ultraviolet cut layer is arbitrary as long as it can weaken the intensity of ultraviolet rays. 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.

As an example of a specific product of the ultraviolet cut layer, cut ace (MKV Plastic Co., Ltd.) and the like can be mentioned. In addition, the ultraviolet cut layer may be formed of one type of material or may be formed of two or more types of materials.
Moreover, the ultraviolet cut layer may be formed of a single layer film, but may be a laminated film including two or more films. The thickness of the ultraviolet cut layer is not particularly limited, but is usually 5 μm or more and 200 μm or less.

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

  Moreover, in order to take out the electricity generated by the organic thin film solar cell element, the organic thin film solar cell module may have a current collector connected to the organic thin film solar cell element via an electric extraction portion. The configuration and forming method of the electron take-out portion and the current collecting wire can be formed by known materials and methods. For example, it can be formed by the materials and methods described in JP-A-2014-239087.

<2. Manufacturing method of organic thin film solar cell module>
Hereinafter, although the manufacturing method of the organic thin film solar cell module which concerns on this invention is demonstrated, the manufacturing method of the organic thin film solar cell module which concerns on this invention is not limited to the following, The organic thin film solar cell module which concerns on this invention As long as can be manufactured, it may be manufactured in any way. The organic thin film solar cell module according to the present invention can be manufactured by a step of manufacturing the organic thin film solar cell element 4 on the support 3 and a step of sealing the organic thin film solar cell element 4.

<2-1. Process for producing organic thin-film solar cell element on support>
What is necessary is just to form each member which comprises the organic thin film solar cell element 4 by laminating | stacking sequentially on the support body 3 by said method as a process of manufacturing the organic thin film solar cell element 4 on the support body 3. FIG. In addition, when laminating the constituent members of the organic thin film solar cell element 4, the support 3 may be handled individually as a single sheet, or may be handled by a so-called roll-to-roll continuous conveyance operation. However, when the support 3 has flexibility, in order to improve productivity, it is preferable to manufacture the organic thin-film solar cell element 4 by laminating each constituent member by a roll-to-roll method. .

<2-2. Sealing process>
Next, the laminated body of the support body 3 and the organic thin film solar cell element 4 is combined with the laminated body of the first adhesive layer 2 and the first sealing substrate 1, the second adhesive layer 5 and the second sealing member. An organic thin film solar cell module can be manufactured by bonding and sealing with a laminated body with the stop base material 6.

  There are no particular restrictions on the manufacturing method of the laminate of the first adhesive layer 2 and the first sealing substrate 1 and the laminate of the second adhesive layer 5 and the second adhesive layer 6, which are publicly known. It can be manufactured by a method. For example, the first sealing substrate 1 and the first adhesive layer 2 formed in a sheet shape, and the second sealing substrate 6 and the second adhesive layer 5 formed in a sheet shape are respectively autoclaved. Each laminated body can be produced by bonding by bonding, hot pressing, vacuum lamination, or roll lamination. These treatments may be performed in any environment, but are preferably performed in a clean room and particularly preferably performed in a dry clean room in order to avoid contamination by foreign substances. By performing it in a dry clean room, it is possible to prevent moisture from being contained in the manufactured laminate.

  The temperature at which lamination is carried out varies depending on the materials constituting each sealing substrate and each adhesive layer, but prevents the first sealing substrate 1 and the second sealing substrate 6 from being denatured by heat. In order to prevent this, it is preferable to carry out at a temperature of room temperature to 150 ° C.

  Moreover, you may produce each laminated body by apply | coating the adhesive material dissolved in the solvent to the 1st sealing base material 1 and the 2nd sealing base material 6, and making it dry. Examples of the application method include air spray application, airless spray application, and application using a roll coater. In view of production efficiency, application by a roll coater is preferable. In any case, in order to avoid mixing of foreign substances, it is preferable to perform in a clean room, particularly preferably in a dry clean room. By applying in a dry clean room, it is possible to prevent moisture from being contained in the manufactured laminate. In addition, it is preferable that the 1st sealing base material 1 and the 1st contact bonding layer 2, and the 2nd sealing base material 6 and the 2nd contact bonding layer 5 respectively have the same laminated surface.

  The laminated body of the first sealing substrate 1 and the first adhesive layer 2 and the laminated body of the second sealing substrate 6 and the second adhesive layer 5 are produced by using the organic thin film. Although it may be performed before or after being processed into a shape to be installed in the solar cell, the laminate is preferably manufactured before processing in order to increase production efficiency.

  The laminated body of the support body 3 and the organic thin film solar cell element 4, the laminated body of the 1st sealing base material 1 and the 1st contact bonding layer 2, and the 2nd sealing base material 6 and 2nd adhesion | attachment. When sealing with the laminated body with the layer 5, it can seal by preparing so that each member may be laminated | stacked by the structure shown in FIG. 2, and bonding by roll lamination or vacuum lamination. The lamination temperature varies depending on the material used, but is not less than room temperature and not more than 150 ° C. in order to prevent the first sealing substrate 1, the support 3, and the second sealing substrate 6 from being denatured by heat. Preferably there is.

In addition, as shown in FIG. 3, a part of 1st contact bonding layer 2 and a part of 2nd contact bonding layer 5 are bonded, and the laminated body of the support body 3 and the organic thin film solar cell element 4 is included. In the case of such a configuration, first, the support 3 on which the organic thin-film solar cell element 4 is formed is cut into a predetermined size, and then the first sealing base material 1 and the first sealing substrate 1 having a size that can include the support 3. A laminated body with one adhesive layer 2 and a laminated body with the second sealing substrate 6 and the second adhesive layer 5 are prepared, and the lamination order of FIG. What is necessary is just to paste.

  Although the bonding environment is not particularly specified, it is preferably performed in a clean room in order to suppress the entry of foreign matter, and further, the bonding is performed in a dry clean room in order to prevent moisture from entering. Is preferred.

  In addition, the sealing process of the laminated body of the support body 3 and the organic thin-film solar cell element 4 may be performed by a single wafer method or a roll-to-roll method. When the material, the support, and the second sealing substrate have flexibility, it is preferable to perform the roll-to-roll method in order to improve productivity.

  The use of a polyolefin-based resin for the first adhesive layer 2 and the second adhesive layer 5 has a plurality of preferable points in the manufacturing process. First, polyolefin resins generally do not require a curing step at high temperatures, unlike thermosetting ethylene-vinyl acetate copolymer resins and epoxy resins. For this reason, while being able to shorten lamination time, ie, the time which a sealing process requires, the thermal damage to each member which comprises the organic thin film solar cell element 4 can be reduced. Secondly, since the polyolefin-based resin is made of a hydrophobic material, the water content of the resin is less than that of an ethylene-vinyl acetate copolymer resin, an epoxy resin or the like containing a hydrophilic group. For this reason, the damage to the organic thin film solar cell element 4 by the trace amount water | moisture content which the 1st adhesive layer 2 and the 2nd adhesive layer 5 bring into the organic thin film solar cell element 4 can be reduced. Thirdly, the polyolefin resin has a smaller shrinkage ratio after adhesion (after element sealing) than the curable ethylene-vinyl acetate copolymer resin and epoxy resin. Therefore, in the manufacturing process of the organic thin film solar cell module, damage to the element due to curing shrinkage can be reduced, and warping of the support during the production of the large area solar cell module can be suppressed.

The organic thin film solar cell module according to the present invention can be formed by the above-described method.
In addition, although it is as above-mentioned about the organic thin-film solar cell element shown in FIG. 2 which concerns on one Embodiment of this invention, each component layer is the above-mentioned also regarding the organic thin-film solar cell module shown in FIG. 4 which concerns on other embodiment. It can form using the material and method quoted by each structure layer. That is, the organic thin film solar cell element has a pair of transparent electrodes, and the adhesive layer contains a polyolefin resin.

EXAMPLES Hereinafter, although the Example of this invention is shown and this invention is demonstrated more concretely, this invention is not limited to a following example, unless it deviates from the summary.
<Synthesis example of copolymer A>

  4,4-bis (2-ethylhexyl) -2,6-bis (trimethyltin) -dithieno obtained as a monomer in a 50 mL two-necked eggplant flask under nitrogen with reference to the method described in the known document WO2013 / 180243. [3,2-b: 2 ′, 3′-d] silole (Compound E1, 107 mg, 0.144 mmol) and 4,4-dioctyl- obtained by referring to the method described in the known document WO2013 / 180243 2,6-bis (trimethyltin) -dithieno [3,2-b: 2 ′, 3′-d] silole (compound E2, 107 mg, 0.144 mmol)) and known literature (Organic Letters Vol. 6, 3381- 3384, 2004) obtained by referring to the method described in Compound (E3: 1,3-dibromide). Mo-5- (n-octyl) -4H-thieno [3,4-c] pyrrole-4,6- (5H) -dione, 61 mg, 0.144 mmol) and known literature (Organic Letters Vol. 6, 3381- 3384, 2004), obtained by referring to the method described in Compound (E4: 1,3-dibromo-5- (4-n-octyloxyphenyl) -4H-thieno [3,4] -C] pyrrole-4,6- (5H) -dione, 74 mg, 0.144 mmol), tetrakis (triphenylphosphine) palladium (0) (10 mg, 3 mol%), heterogeneous complex catalyst Pd- EnCatTPP30 (manufactured by Aldrich, 13 mg, 1.3 weight ratio of tetrakis (triphenylphosphine) palladium (0)), Ene (8 mL), and N, placed N- dimethylformamide (1.6 mL), 1 hour at 90 ° C., followed by stirring for 10 hours at 100 ° C.. After adding and diluting 8 mL of toluene to the reaction solution and further heating and stirring for 0.5 hour, as a terminal treatment, trimethyl (phenyl) tin (0.4 mL) was added and stirring was continued for 2 hours, and further bromobenzene (4 mL). Was added with stirring for 8 hours, the reaction solution was poured into methanol, and the deposited precipitate was collected by filtration. The obtained solid was dissolved in chloroform, diamine silica gel (Fuji Silysia Chemical) was added, and the mixture was stirred for 10 minutes at room temperature, and passed through a short column of acidic silica gel. The solution was concentrated, recrystallized using chloroform / ethyl acetate as a solvent, and the deposited precipitate was separated by filtration to obtain the target copolymer 10 in a yield of 65%. The weight average molecular weight Mw was 269000, and PDI was 5.0.

(Preparation of organic power generation layer ink)
Copolymer A obtained in the synthesis example as a p-type semiconductor compound and a mixture of C ₆₀ PCBM and C ₇₀ PCBM (Nanom Spectra-E123 manufactured by Frontier Carbon Co.) as an n-type semiconductor compound so as to have a mass ratio of 1: 4 And dissolved in a mixed solvent of ortho-xylene and tetralin (volume ratio 9: 1) so that the mixture has a concentration of 5.6% by mass. This solution was stirred and mixed on a hot stirrer at a temperature of 80 ° C. for 1 hour. The solution after stirring and mixing was filtered with a PTFE filter to prepare an ink for forming an active layer.

(Preparation of ink for forming the electron take-out layer)
Zinc diacrylate (manufactured by Nippon Shokubai Co., Ltd., 24 g) and ethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., 12 g) were dissolved in ethanol (manufactured by Wako Pure Chemical Industries, Ltd., 364 g) and subjected to ultrasonic dispersion treatment for 10 minutes. Filtration under reduced pressure was performed with a PTFE membrane filter having a diameter of 0.5 μm to produce a colorless and transparent electron extraction layer ink.

<Example 1: Production of sealed element 1 of photoelectric conversion element>
125 μm thick polyethylene naphthalate (PEN, manufactured by Teijin DuPont) A transparent electrode substrate composed of indium tin oxide (ITO) film / silver film / ITO was prepared on a film, and an Nd: YAG laser ( Electrode patterning was performed with a laser marker (manufactured by Keyence Corporation) using 532 nm. After electrode patterning, the substrate was washed with a cloth impregnated with isopropanol and dried by nitrogen blowing.

  An electron extraction layer forming ink was applied to the cleaned substrate at a rate of 1 m / min using a slot die coater so that the wet film thickness was 6.4 μm. After applying the electron extraction layer forming ink, the substrate was heated in the atmosphere at 150 ° C. for 20 minutes to form an electron extraction layer composed of a zinc oxide-containing layer of about 40 nm.

Next, the active layer forming ink was applied onto the electron extraction layer at a rate of 0.4 m / min using a slot die coater so that the wet film thickness was 8 μm. After applying the ink for forming the active layer, the substrate was heated at 40 ° C. for 10 minutes in a nitrogen atmosphere to form an active layer of about 350 nm.

  After forming the active layer, a poly (3,4-ethylenedioxythiophene) poly (styrenesulfonic acid) dispersion (PEDOT-PSS) was applied at a rate of 0.25 m / min using a slot die coater. After applying the dispersion, the substrate was subjected to a heat treatment at 40 ° C. for 10 minutes in a nitrogen atmosphere to form a hole extraction layer of about 400 nm.

  Next, a 30 nm indium / zinc oxide (IZO) film, an 8 nm silver film, and a 40 nm IZO film are formed in this order on the hole extraction layer by a sputtering method to form a transparent electrode. A corner see-through photoelectric conversion element was completed.

For the obtained photoelectric conversion element, a 0.7 mm thick glass substrate (NA32SG manufactured by Avant Straight) and a polyolefin resin sheet (Z-74 manufactured by Dai Nippon Printing Co., Ltd.) were used, a glass substrate, a polyolefin resin sheet, and a photoelectric conversion. The element, polyolefin resin sheet, and glass substrate are stacked in this order, and this is vacuum-laminated using a vacuum heating laminator (manufactured by NPC) at 130 ° C for 5 minutes, and then laminated by pressing for 15 minutes. And the sealing body of the see-through type photoelectric conversion element was produced.

(Evaluation of photoelectric conversion element)
A 6 mm square metal mask is attached to the sealing body of the produced photoelectric conversion element, a solar simulator with an air mass (AM) of 1.5 G and an irradiance of 100 mW / cm ² is used as an irradiation light source, and a source meter (Model 2400 manufactured by Keithley). ), Current-voltage characteristics between the electrodes were measured, and conversion efficiency was calculated. The obtained results are shown in Table 1.

(Durability evaluation of photoelectric conversion elements)
Using a thermo-hygrostat (manufactured by Espec Corp.), the sealed body of the photoelectric conversion element was exposed for 100 hours under the conditions of 85 ° C. and relative humidity of 85%. After returning the sealing body of the photoelectric conversion element to room temperature, the current-voltage characteristics between the electrodes were measured by the same apparatus and method as described above, and the conversion efficiency was calculated. The obtained results are shown in Table 1.

<Comparative Example 1: Production of sealed element 2 of photoelectric conversion element>
Instead of the polyolefin resin sheet (Dai Nippon Printing Co., Ltd. Z-74), an ethylene / vinyl acetate copolymer resin sheet (EVA, UF Kasei UFHCE-400) was used to make a glass substrate, ethylene / vinyl acetate copolymer resin. Sheets, photoelectric conversion elements, ethylene / vinyl acetate copolymer resin sheets, glass substrates were laminated in that order, and the photoelectric bonding was performed in the same manner as in Example 1 except that the crimping time during the lamination process was 25 minutes. The sealing element 2 of the conversion element was produced and evaluated by the same method as in Example 1. The obtained results are shown in Table 1.

  In Table 1, the maintenance rate means the maintenance rate of the conversion efficiency after the durability test with respect to the initial conversion efficiency. That is, the maintenance factor was calculated as (conversion efficiency after durability test / initial conversion efficiency) × 100%.

  As shown in Table 1, the photoelectric conversion element sealing body obtained in Example 1 has a higher photoelectric conversion efficiency as an initial value than the photoelectric conversion element sealing body obtained in Comparative Example 1. Indicated. Furthermore, in Comparative Example 1, it can be seen that the conversion efficiency decreases after the durability test, whereas in Example 1, the conversion efficiency decreases little after the durability test. The reason for this is that the ethylene-vinyl acetate copolymer, which is the adhesive layer used in Comparative Example 1, has a large shrinkage after thermosetting, and the transparent electrode in direct contact with the adhesive layer is damaged during the sealing process. It is considered that the conversion efficiency is lowered. Further, the difference in characteristics after the high temperature and high humidity durability test is remarkable between the examples and the comparative examples, and this is due to the fact that high water resistance can be secured by the sealing configuration of the present invention. The first reason is the hydrophobicity of the polyolefin resin, and the moisture permeability is much smaller than that of the ethylene-vinyl acetate copolymer resin. This is because the speed at which water vapor reaches the photoelectric conversion element can be extremely slow. A second reason is the moisture resistance of the polyolefin resin itself. Ethylene-vinyl acetate copolymer may be hydrolyzed at high temperature and high humidity, and the adhesiveness may be deteriorated or corrosion by acid as a result of hydrolysis may occur. However, polyolefin resin does not have such a concern. As a result, when the polyolefin resin is used in the sealing configuration according to the present invention, high durability can be achieved.

DESCRIPTION OF SYMBOLS 1 1st sealing base material 2 1st contact bonding layer 3 Support body 4 Organic thin film solar cell element 5 2nd contact bonding layer 6 2nd sealing base material 101 Lower electrode 102 Electron extraction layer 103 Organic photoelectric converting layer 104 Hole extraction layer 105 Upper electrode

Claims (5)

An organic thin film solar cell element having a support, an organic thin film solar cell element, an adhesive layer, and a sealing substrate in this order,
The organic thin film solar cell module has a pair of transparent electrodes,
The said adhesion layer contains polyolefin resin, The organic thin film solar cell module characterized by the above-mentioned. The organic thin film solar which has a 1st sealing base material, a 1st contact bonding layer, a support body, an organic thin film solar cell element, a 2nd contact bonding layer, and a 2nd sealing base material in this order. A battery module,
The organic thin film solar cell element has a pair of transparent electrodes,
The organic thin film solar cell module, wherein the first adhesive layer and the second adhesive layer contain a polyolefin-based resin.   The organic thin film solar cell element is covered with the first adhesive layer and the second adhesive layer by bonding the end of the first adhesive layer and the end of the second adhesive layer together. The organic thin film solar cell module according to claim 2, wherein   The organic thin-film solar cell module according to claim 2 or 3, wherein the first sealing substrate and the second sealing substrate are glass substrates. 5. The water vapor transmission rate per 50 μm thickness of each of the first adhesive layer and the second adhesive layer is 20 g / m ² / day or less. 5. Organic thin-film solar cell module.