JP2020047827A - Dye-sensitized solar cell with protective layer - Google Patents

Abstract

To further improve an output of a DSC and maintain performance for a longer period.SOLUTION: The dye-sensitized solar cell with a protective layer includes: a first conductive substrate; a second conductive substrate facing the first conductive substrate; one or more power generation units 44 located between the first conductive substrate and the second conductive substrate; a dye-sensitized solar cell 10 having a surface of the first conductive substrate as a light-receiving surface; and a first moisture-proof layer covering the surface of the first conductive substrate. The power generation unit 44 includes an inorganic semiconductor layer 12 and an electrolytic solution 14. Water content of the electrolytic solution 14 is 100 to 8000 mass ppm with respect to the total mass of the electrolytic solution 14. The first moisture-proof layer has translucency.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a dye-sensitized solar cell with a protective layer.

As a solar cell, a silicon-based solar cell is widely used. Silicon-based solar cells have problems such as stable supply of high-purity silicon as a raw material and high cost.
As another solar cell, there is a dye-sensitized solar cell (DSC). As the DSC, there is a so-called Gretzell-type solar cell. The Gretzell-type DSC has a photoelectrode, a counter electrode facing the photoelectrode, and a charge transfer body (for example, an electrolytic solution) located between the two electrodes.
DSC has a problem that its output is lower than that of silicon-based solar cells. There is also a problem that the battery life is short.
To cope with such a problem, Patent Document 1 discloses a dye-sensitized solar cell in which both or either the oxygen concentration or the water concentration in the electrolyte is equal to or less than a specific value.

JP 2000-323189 A

However, DSCs are required to further improve output and maintain performance for a long time.
Therefore, an object of the present invention is to provide a DSC with a protective layer that can further improve output and maintain performance for a longer period.

The present invention has the following aspects.
[1] a first conductive substrate, a second conductive substrate facing the first conductive substrate, the first conductive substrate and the second conductive substrate, One or more power generation units located between, and a dye-sensitized solar cell having a surface of the first conductive substrate as a light receiving surface,
Having a first moisture-proof layer covering the surface of the first conductive substrate,
The power generation unit has an inorganic semiconductor layer and an electrolyte,
The water content of the electrolytic solution is 100 to 8000 mass ppm with respect to the total mass of the electrolytic solution,
The first moisture-proof layer is a dye-sensitized solar cell with a protective layer having a light-transmitting property.
[2] The dye-sensitized solar cell with a protective layer according to [1], wherein the peel strength between the first conductive substrate and the first moisture-proof layer is 8 to 15 N / cm.
[3] further comprising a first adhesive layer located between the first moisture-proof layer and the first conductive substrate,
The dye-sensitized solar cell with a protective layer according to [1] or [2], wherein the first adhesive layer has a water vapor transmission rate of 0 to 200 g / m ² / day.
[4] The dye-sensitized solar cell with a protective layer according to any one of [1] to [3], further including a second moisture-proof layer covering a surface of the second conductive substrate.
[5] The dye-sensitized solar cell with a protective layer according to [4], wherein the peel strength between the second conductive substrate and the second moisture-proof layer is 8 to 15 N / cm.
[6] further comprising a second adhesive layer located between the second moisture-proof layer and the second conductive substrate,
The dye-sensitized solar cell with a protective layer according to [4] or [5], wherein the second adhesive layer has a water vapor transmission rate of 0 to 200 g / m ² / day.

  According to the DSC with a protective layer of the present invention, the output can be further improved and the performance can be maintained for a longer period.

1 is a plan view of a dye-sensitized solar cell with a protective layer according to one embodiment of the present invention, as viewed from the counter electrode side, and is a diagram showing a state where the dye-sensitized solar cell has passed through a moisture-proof layer. It is II-II sectional drawing of FIG. It is the schematic of the II-II cross section of FIG.

(Dye-sensitized solar cell with protective layer)
The dye-sensitized solar cell with a protective layer according to the present invention includes a dye-sensitized solar cell (DSC) and a first moisture-proof layer that covers a light-receiving surface of the DSC.
Hereinafter, an embodiment of a DSC with a protective layer according to the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the DSC 1 with a protective layer according to the present embodiment to which the present invention is applied includes a DSC 10 and a protective layer 2.

The DSC 10 includes a photoelectrode 41, a counter electrode 42, a power generation unit 44, a sealing material 46, and a conductive material 48.
The surfaces of the photoelectrode 41 and the counter electrode 42 face each other with an interval. Hereinafter, the direction in which the photoelectrode 41 and the counter electrode 42 face each other is referred to as a stacking direction D3 (third direction).

  The photoelectrode 41 is intermittently provided on the photoelectrode support 21, the photoelectrode conductive layer 31 (transparent electrode film) provided on the inner surface 21 a of the photoelectrode support 21, and the dye-adsorbed photoelectrode conductive layer 31. And a plurality of inorganic semiconductor layers 12 (semiconductor layers) stacked. In the present embodiment, the first electrode substrate 21 and the photoelectrode conductive layer 31 constitute a first conductive substrate.

The photoelectrode support 21 is a member serving as a base for the photoelectrode conductive layer 31, the inorganic semiconductor layer 12, the sealing material 46, and the conductive material 48. The material of the photoelectrode support 21 is flexible enough to be applicable to continuous production of solar cells using a so-called roll-to-roll (RtoR) method, and can be formed into a large-area film shape. Good. Examples of the material of the photoelectrode support 21 include transparent resin materials such as polyethylene terephthalate (PET), acrylic, polycarbonate, polyethylene naphthalate (PEN), and polyimide.
Note that, in plan view, the photoelectrode support 21 is formed in a rectangular shape. Hereinafter, the directions in which the sides of the photoelectrode support 21 extend in the plan view are referred to as a D1 direction (first direction) and a D2 direction (second direction). The direction D1 and the direction D2 are orthogonal to each other.

As shown in FIG. 2, the photoelectrode conductive layer 31 is formed on the entire inner surface 21a of the photoelectrode support 21 (that is, the surface of the photoelectrode support 21 on the side of the counter electrode 42) in the D1 direction. The photoelectrode conductive layer 31 is laminated over the entire inner surface 21 a of the photoelectrode support 21. Examples of the material of the photoelectrode conductive layer 31 include indium tin oxide (ITO) and zinc oxide.
The photoelectrode support 21 and the photoelectrode conductive layer 31 are both transparent, and transmit light incident from the photoelectrode support 21.
In the present embodiment, the outer surface (front surface) 21b of the photoelectrode 41 is a light receiving surface.

  The inorganic semiconductor layer 12 is formed on the inner surface of the photoelectrode conductive layer 31 (that is, the surface of the photoelectrode conductive layer 31 on the side of the counter electrode 42). A plurality of inorganic semiconductor layers 12 are arranged at intervals in the D1 direction. Each inorganic semiconductor layer 12 is formed in a belt shape long in the direction D2.

The inorganic semiconductor layer 12 is, for example, a porous layer dyed by carrying a sensitizing dye on a metal oxide or the like, and has a function of receiving and transporting electrons from the sensitizing dye. Examples of such a metal oxide include titanium oxide (TiO ₂ ), zinc oxide (ZnO), and tin oxide (SnO ₂ ).

  The above-mentioned sensitizing dye is composed of an organic dye or a metal complex dye. Examples of the organic dye include various organic dyes such as coumarin, polyene, cyanine, hemicyanine, and thiophene. Examples of the metal complex dye include a ruthenium complex and the like.

  The counter electrode 42 is provided on the counter electrode support 22 (base material) facing the photoelectrode support 21 and on the inner surface 22a of the counter electrode support 22 (the surface of the counter electrode support 22 on the photoelectrode 41 side). And a counter electrode conductive layer 32 (transparent electrode film). In the present embodiment, the counter electrode support 22 and the counter electrode conductive layer 32 form a second conductive base material.

  The counter electrode support 22 is a member serving as a base of the counter electrode conductive layer 32. Like the photoelectrode support 21, the material of the counter electrode support 22 is flexible enough to be applicable to continuous production of solar cells using the RtoR method, and can be formed into a large-area film shape. There is no particular limitation. Examples of the material of the counter electrode support 22 include the same resin material as that of the photoelectrode support 21.

  The counter electrode conductive layer 32 is formed on the entire inner surface 22a of the counter electrode support 22 in the direction D1. The counter electrode conductive layer 32 is stacked on the inner surface 22 a of the counter electrode support 22. Examples of the material of the counter electrode conductive layer 32 include the same compounds as those of the photoelectrode conductive layer 31. In the present embodiment, the first electrode base 22 and the counter electrode conductive layer 32 constitute a first conductive substrate.

  The power generation unit 44 is sandwiched between the photoelectrode 41 and the counter electrode 42. A plurality of power generation units 44 are provided at intervals along the surface direction of the photoelectrode 41 and the counter electrode 42 (the direction D1 shown in FIG. 4). The power generation unit 44 includes the inorganic semiconductor layer 12 and the electrolyte 14.

Electrolyte solution 14 is filled between photoelectrode 41 and counter electrode 42. Electrolyte solution 14 is in contact with inorganic semiconductor layer 12.
The electrolytic solution 14 has a dispersion medium (particularly, sometimes referred to as an “electrolyte dispersion medium”) and a redox couple dispersed in the electrolytic solution dispersion medium.

  The electrolyte dispersion medium is a non-aqueous solvent, an ionic liquid, or the like. Non-aqueous solvents include acetonitrile, propionitrile and the like. The ionic liquid is dimethylpropyl imidazolium iodide, butyl methyl imidazolium iodide, or the like.

A redox couple is a combination of a supporting electrolyte and a halogen molecule.
The supporting electrolyte includes metal iodides such as lithium iodide, sodium iodide and potassium iodide; iodides such as iodine salts such as tetraalkylammonium iodide, pyridinium iodide and imidazolium iodide; sodium bromide and bromide Metal bromides such as potassium; and bromine compounds such as bromide salts such as tetraalkylammonium bromide, pyridinium bromide and imidazolium bromide.
The halogen molecule is an iodine molecule, a bromine molecule, or the like.
As the combination of the supporting electrolyte and the halogen molecule, a combination of an iodide and an iodine molecule and a combination of a bromine compound and a bromine molecule are preferable.

The content of the supporting electrolyte with respect to the total volume of the electrolytic solution 14 can be determined in consideration of the type of the supporting electrolyte and the like. The content of the supporting electrolyte with respect to the total volume of the electrolytic solution 14 is, for example, preferably 0.1 to 10 mmol / L, and more preferably 0.2 to 2 mmol / L.
The content of the halogen molecule with respect to the total volume of the electrolyte solution 14 can be determined in consideration of the content of the supporting electrolyte and the like. The content of halogen molecules with respect to the total volume of the electrolyte solution 14 is preferably 0.001 to 1 mmol / L.

  Electrolyte solution 14 may include t-butylpyridine. Since the electrolyte solution 14 contains t-butylpyridine, the reverse electron transfer reaction is easily prevented.

Electrolyte solution 14 contains water. The water content of the electrolytic solution 14 is preferably from 10 to 8,000 ppm by mass, more preferably from 300 to 5,000 ppm by mass, and still more preferably from 500 to 2,500 ppm by mass, based on the total mass of the electrolytic solution 14. If the water content is equal to or higher than the lower limit, the output of the DSC 10 can be increased. When the water content is equal to or less than the upper limit, the performance of the DSC 10 can be maintained for a longer period.
The method for measuring the water content of the electrolytic solution 14 is coulometric titration (JIS K0113: 2005).

  The sealing material 46 seals the electrolytic solution 14 between the photoelectrode 41 and the counter electrode 42 to form the power generation unit 44. That is, the sealing material 46 seals the electrolytic solution 14 in the power generation unit 44. The sealing material 46 seals the power generation unit 44 containing the electrolytic solution 14 together with the seal unit 60 shown in FIG. The sealing members 46 are provided on both sides of the power generation unit 44 in the direction D1 shown in FIGS. The sealing material 46 is provided adjacent to the power generation unit 44 in the direction D1. The sealing material 46 is arranged between the inorganic semiconductor layers 12 adjacent in the D1 direction. The sealing member 46 has a plurality of power generation sections 44 formed along the direction D1. Note that a pair of the sealing members 46 are arranged between the power generation units 44 adjacent in the D1 direction.

The sealing material 46 is a cured product of the sealing material composition. The sealing material 46 bonds the photoelectrode 41 and the counter electrode 42 to each other.
Examples of the material of such a sealing material composition include a resin material containing at least one resin among a thermoplastic resin, a thermosetting resin, and an ultraviolet-curable resin.
Examples of the thermoplastic resin include polyvinyl butyral (PVB), polyisobutylene (PIB), polyolefin, polystyrene, ionomer resin, and isobutylene elastomer.
Examples of the thermosetting resin include an epoxy resin, a polyester resin, a urethane resin, a silicone resin, and ethylene vinyl acetate (EVA).
Examples of the ultraviolet curable resin include an acrylic resin, a urethane resin, a vinyl ester resin, an alkyd resin, and the like.
Among these resins, a thermosetting resin and an ultraviolet curable resin are preferable, a thermosetting resin is more preferable, and an epoxy resin is further preferable. These resins have excellent water vapor barrier properties.

Water vapor permeability of the sealing member 46 is preferably not more than 0~2000g ^/ m 2 ^/ day, more preferably not more than 0~1000g ^/ m 2 ^/ day, more preferably not more than 0~500g ^/ m 2 ^/ day.
The water vapor transmission rate of the sealing material 46 is obtained by a differential pressure method (JIS K7126-1: 2006) or an equal pressure method (JIS K7126-1: 2006).

  The thickness T46 of the sealing material 46 is, for example, preferably 10 to 150 μm, more preferably 20 to 100 μm, and still more preferably 30 to 80 μm. The thickness T46 is the length of the sealing material 46 in the stacking direction D3.

  The width W46 of the sealing material 46 is, for example, preferably 2 to 15 mm, more preferably 3 to 10 mm, and still more preferably 4 to 8 mm. When the width W46 is equal to or larger than the lower limit, the moisture resistance can be further improved. When the width W46 is equal to or less than the upper limit, the surface area of the power generation unit 44 can be further increased. The width W46 is the length of the sealing material 46 in the direction D1.

  A conductive material 48 is provided between a pair of sealing materials 46 arranged between the power generation units 44 adjacent to each other in the D1 direction. The conducting material 48 electrically connects the power generating units 44 including the inorganic semiconductor layer 12 and the electrolytic solution 14 to each other to conduct electricity. The material of the conductive member 48 is not particularly limited as long as it is a conductive material. Examples of the material include a known conductive material, conductive paste, or a mixture of conductive fine particles and an adhesive. In the illustrated example, as an example of the conductive material 48, a conductive paste obtained by mixing an appropriate amount of the conductive particles 36 with an adhesive 38 such as an epoxy resin or a phenol resin is used. This configuration is preferable because the conductive member 48 can be easily cut when the DSC 10 is cut out in a desired pattern. A binder made of the same material as the sealing material 46 may be used for the conductive material 48.

The conductive particles 36 of the present embodiment are coated particles having a core 36a and a coating layer 36b.
The core 36a is, for example, a resin such as polymethyl methacrylate.
As the coating layer 36b, for example, a conductive thin film such as nickel and gold is used.
The conductive particles 36 may be particles made of a conductive material such as metal and carbon.

  The photoelectrode conductive layer 31 and the counter electrode conductive layer 32 are provided with a first insulating portion 50A and a second insulating portion 50B, respectively. The first insulating portion 50A and the second insulating portion 50B are provided at portions overlapping the sealing material 46 of the photoelectrode conductive layer 31 and the counter electrode conductive layer 32 in a cross section orthogonal to the direction D1 shown in FIG. I have. In other words, the first insulating part 50A and the second insulating part 50B overlap the sealing material 46 in the stacking direction D3. The first insulating portion 50A and the second insulating portion 50B are provided in a belt shape long in the direction D2 in plan view.

  The photoelectrode conductive layer 31 of the photoelectrode 41 is provided with a first insulating portion 50A. The counter electrode conductive layer 32 of the counter electrode 42 is provided with a second insulating portion 50B. In the example shown in FIG. 2, the first insulating part 50A and the second insulating part 50B penetrate the photoelectrode conductive layer 31 or the counter electrode conductive layer 32 in the thickness direction. In other words, the first insulating portion 50A divides (electrically blocks) the photoelectrode conductive layer 31 in the direction D1. The second insulating portion 50B divides (electrically cuts off) the counter electrode conductive layer 32 in the direction D1.

  As described above, the conducting material 48 electrically connects the photoelectrode 41 and the counter electrode 42 in the stacking direction D3. The first insulating part 50A and the second insulating part 50B locally insulate the photoelectrode 41 and the counter electrode 42 in the direction D1. Thereby, the power generation units 44 adjacent in the D1 direction are electrically connected to each other in series.

  As shown in FIG. 1, the DSC 10 is provided with a seal part 60 (fusion part, ultrasonic fusion part, joint part). The seal part 60 is provided at a predetermined position in the direction D2 of the DSC 10. In the seal portion 60, the photoelectrode 41 and the counter electrode 42 are bonded together over the entire length of the DSC 10 in the D1 direction.

  The seal portion 60 is a portion that is electrically insulated by pressing the photoelectrode support 21 and the counter electrode support 22 together. The photoelectrode support 21 and the counter electrode support 22 are, for example, ultrasonically fused from the outside (that is, above and below the DSC 10) in the thickness direction (stacking direction D3) of the photoelectrode 41 and the counter electrode 42. By applying or pressing a force to the photoelectrode 41 and the counter electrode 42 using the method described above, the pressure can be applied. The photoelectrode conductive layer 31, the counter electrode conductive layer 32, the inorganic semiconductor layer 12, and the electrolytic solution 14 are interposed between the pressed photoelectrode support 21 and the counter electrode support 22 with a small thickness. May be. However, since these layers are substantially separated from each other in the seal portion 60, the power generation portions 44 adjacent to the seal portion 60 are not electrically connected to each other.

  As shown in FIG. 1, the photoelectrode 41 and the counter electrode 42 are provided with an extraction electrode section 71. The extraction electrode unit 71 is electrically connected to the power generation unit 44. The extraction electrode unit 71 extracts the electric power generated by the power generation unit 44. In the present embodiment, the extraction electrode unit 71 is provided at an end of the photoelectrode 41 in the D1 direction. The extraction electrode portion 71 is formed by exposing the photoelectrode conductive layer 31 to the counter electrode 42 side along the stacking direction D3. In the illustrated example, the photoelectrode 41 is larger in the D1 direction than the counter electrode 42, and the end of the photoelectrode 41 projects in the D1 direction with respect to the counter electrode 42. As a result, the photoelectrode conductive layer 31 forms the extraction electrode portion 71. The extraction electrode portion 71 is longer in the direction D2 than in the direction D1.

As shown in FIGS. 1 to 3, the protective layer 2 seals the DSC 10. As shown in FIGS. 2 and 3, the protective layer 2 includes a photoelectrode-side moisture-proof film 81 and a counter electrode-side moisture-proof film 82 that sandwich the DSC 10 in the stacking direction D3.
As shown in FIGS. 1 and 3, in plan view, the photoelectrode-side moisture-proof film 81 and the counter electrode-side moisture-proof film 82 protrude outward from the DSC 10 in both the D1 direction and the D2 direction. The periphery of the DSC 1 with the protective layer is sealed with the photoelectrode-side adhesive layer 84 and the counter electrode-side adhesive layer 86.
In the present embodiment, the photoelectrode-side moisture-proof film 81 has translucency. Since the photoelectrode-side moisture-proof film 81 has translucency, light enters the power generation unit 44 from the light receiving surface. “Translucency” is a property of transmitting light to such an extent that the power generation unit 44 can generate power.
The photoelectrode-side moisture-proof film 81 includes a photoelectrode-side barrier layer 83 and a photoelectrode-side adhesive layer 84. In the present embodiment, the photoelectrode-side barrier layer 83 is a first moisture-proof layer. In the present embodiment, the photoelectrode-side adhesive layer 84 is a first adhesive layer.
Examples of the photoelectrode-side barrier layer 83 include a film having an inorganic material layer formed on a resin base material by vapor deposition or sputtering. Examples of the resin substrate include polyester films such as polyethylene terephthalate and polyethylene naphthalate, and polyolefin films such as polyethylene and polypropylene. Examples of the inorganic material forming the inorganic material layer include silica and the like.

The thickness T83 of the photoelectrode-side barrier layer 83 can be determined in consideration of the material. The thickness of the photoelectrode-side barrier layer 83 is, for example, preferably from 10 to 200 μm, more preferably from 20 to 150 μm, and still more preferably from 30 to 80 μm. When the thickness T83 is equal to or larger than the lower limit, the water vapor transmission rate of the photoelectrode-side barrier layer 83 can be further reduced. When the thickness 83 is equal to or less than the upper limit, the flexibility of the DSC 1 with a protective layer can be further enhanced.
The water vapor transmission rate of the photoelectrode-side barrier layer 83 is determined by an equal pressure method or a differential pressure method.

Water vapor transmission rate of the photoelectrode-side barrier layer 83 is preferably ^{0~8 × 10 -3 g / m 2} / day, more preferably ^{0~3 × 10 -3 g / m 2} / day, 0~1 × 10 ^-3 g / m ² / day is more preferred. When the water vapor permeability of the photoelectrode-side barrier layer 83 is equal to or less than the above upper limit, it is possible to further suppress the intrusion of moisture into the electrolyte 14. The water vapor transmission rate of the photoelectrode-side barrier layer 83 can be adjusted by a combination of the material and the thickness of the photoelectrode-side barrier layer 83.

The photoelectrode-side adhesive layer 84 is, for example, a cured product of an adhesive composition. Examples of the adhesive composition include an epoxy resin, polyurethane, butyl rubber, and polyvinyl alcohol.
The thickness T84 of the photoelectrode-side adhesive layer 84 can be determined in consideration of the type of the adhesive. The thickness T84 is preferably from 3 to 80 μm, more preferably from 5 to 50 μm, and still more preferably from 10 to 30 μm. When the thickness T84 is equal to or larger than the lower limit, the photoelectrode-side barrier layer 83 can be more firmly adhered to the DSC 10. When the thickness T84 is equal to or more than the above upper limit, the flexibility of the DSC 1 with a protective layer can be further enhanced.

Water vapor transmission rate of the photoelectrode-side adhesive layer 84 is preferably not more than 0~200g ^/ m 2 ^/ day, more preferably not more than 0~100g ^/ m 2 ^/ day, more preferably not more than 0~10g ^/ m 2 ^/ day.
The water vapor transmission rate of the photoelectrode-side adhesive layer 84 is obtained by an equal pressure method or a differential pressure method.

  The peel strength between the photoelectrode support 21 and the photoelectrode-side barrier layer 83 is, for example, preferably 3 to 20 N / cm, more preferably 5 to 18 N / cm, and still more preferably 8 to 15 N / cm. When the peel strength is equal to or more than the lower limit, the photoelectrode-side barrier layer 83 is less likely to be peeled from the photoelectrode support 21, and water vapor enters the interface between the photoelectrode support 21 and the photoelectrode-side barrier layer 83. Can be prevented. For this reason, the increase in the water content of the electrolytic solution 14 can be further suppressed. When the peel strength is equal to or less than the upper limit, the photoelectrode-side barrier layer 83 can be easily bonded to the photoelectrode support 21. The peel strength depends on the combination of the material of the photoelectrode support 21, the material of the photoelectrode-side barrier layer 83, the type of the adhesive composition forming the photoelectrode-side adhesive layer 84, and the thickness T84 of the photoelectrode-side adhesive layer 84 Can be adjusted.

The opposing electrode-side moisture-proof film 82 may have translucency or may not have translucency.
The opposing-electrode-side moisture-proof film 82 includes an opposing-electrode-side barrier layer 85 and an opposing-electrode-side adhesive layer 86. In the present embodiment, the counter electrode-side barrier layer 85 is a second moisture-proof layer. In the present embodiment, the counter electrode side adhesive layer 86 is a second adhesive layer.
As the counter electrode side barrier layer 85, the same film as the photo electrode side barrier layer 83 can be used. In addition, examples of the counter electrode-side barrier layer 85 include a metal foil, a laminated film of a metal foil and a resin base material, and the like. Among them, a metal foil or a laminated film of a metal foil and a resin substrate is preferable as the porous electrode side barrier layer.
Examples of the metal foil include an aluminum foil.
Examples of the resin substrate of the laminated film include polyester films such as polyethylene terephthalate and polyethylene naphthalate, and polyolefin films such as polyethylene and polypropylene.

  The water vapor transmission rate of the counter electrode side barrier layer 85 is similar to the water vapor transmission rate of the photo electrode side barrier layer 83. The water vapor transmission rate of the counter electrode side barrier layer 85 may be the same as or different from the water vapor transmission rate of the optical electrode side barrier layer 83.

  The thickness T85 of the opposing electrode side barrier layer 85 is the same as the thickness T83 of the photoelectrode side barrier layer 83. The thickness T85 may be the same as or different from the thickness T83.

  The adhesive composition forming the opposing electrode-side adhesive layer 86 is the same as the adhesive composition forming the photoelectrode-side adhesive layer 84. The adhesive composition forming the opposing electrode-side adhesive layer 86 may be the same as or different from the adhesive composition forming the photoelectrode-side adhesive layer 84.

  The thickness T86 of the opposing electrode-side adhesive layer 86 is the same as the thickness T84 of the photoelectrode-side adhesive layer 84. The thickness T86 of the opposing electrode-side adhesive layer 86 may be the same as or different from the thickness T84 of the photoelectrode-side adhesive layer 84.

  The water vapor transmission rate of the opposing electrode side adhesive layer 86 is the same as the water vapor transmission rate of the photo electrode side adhesion layer 84. The water vapor transmission rate of the opposing electrode side adhesive layer 86 may be the same as or different from the water vapor transmission rate of the photo electrode side adhesive layer 84.

  The peel strength between the counter electrode support 22 and the counter electrode side barrier layer 85 is the same as the peel strength between the photo electrode support 21 and the photo electrode side barrier layer 83. The peel strength between the counter electrode support 22 and the counter electrode side barrier layer 85 may be the same as or different from the peel strength between the photo electrode support 21 and the photo electrode side barrier layer 83.

  The electric power generated by the DSC 10 is taken out of the protective layer 2 via a wiring (not shown). The wiring is electrically connected to the extraction electrode unit 71. The wiring is led out through openings formed in the photoelectrode-side moisture-proof film 81 and the counter electrode-side moisture-proof film 82, for example.

(Production method)
A method for manufacturing the DSC 1 with a protective layer will be described.
The method for manufacturing the DSC 1 with the protective layer includes, for example, a DSC manufacturing step and a covering step.

The DSC manufacturing process is a process for obtaining the DSC 10. A method for obtaining DSC includes a method according to a conventionally known production method.
An example of a method for manufacturing a DSC by the RtoR method will be described.

The long photoelectrode 41 is extended. A sealing material composition and a conductive material 48 are applied to the photoelectrode 41 on both sides in the width direction (D1 direction) of the inorganic semiconductor layer 12 along the direction in which the inorganic semiconductor layer 12 extends (direction D2). The region where the inorganic semiconductor layer 12 is located is filled with the electrolytic solution 14.
Next, the long counter electrode 42 is drawn out and overlapped with the photoelectrode 41 to form a laminate. At this time, the inorganic semiconductor layer 12 and the counter electrode conductive layer 32 face each other.
The laminate is passed between a pair of rollers to a desired thickness.
According to the type of the sealing material composition, a treatment such as cooling, heating, and ultraviolet irradiation is performed on the laminate to cure the sealing material.
Thereafter, the seal portions 60 extending in the D1 direction are formed at an arbitrary pitch (length in the D2 direction). As a method of forming the seal portion 60, for example, an ultrasonic vibration method, a heat fusion method, and the like can be given.
Cutting is performed at the formed seal portion 60 to obtain the DSC 10.

The covering step is a step of providing the DSC 10 with the protective layer 2.
In the covering step, the DSC 10 may be sealed with the photoelectrode-side moisture-proof film 81 and the counter electrode-side moisture-proof film 82.
An adhesive composition for forming the counter electrode-side adhesive layer 86 is applied to the counter electrode-side barrier layer 85. DSC1 is mounted on this adhesive composition.
The adhesive composition constituting the photoelectrode-side adhesive layer 84 is applied to the photoelectrode-side barrier layer 83. The photoelectrode-side barrier layer 83 to which the adhesive composition has been applied is placed on the DSC 1 to form a laminate. This laminate has a desired thickness. Next, the adhesive composition is cured to obtain DSC1 with a protective layer.

As described above, according to the DSC 1 with the protective layer according to the present embodiment, since the specific amount of water is contained in the electrolytic solution 14, the output of the DSC 10 can be improved.
In addition, since the DSC 1 with the protective layer has the protective layer 2, it is possible to suppress intrusion of water from the outside. For this reason, the water content of the electrolytic solution 14 does not increase excessively, and the performance of the DSC 1 can be maintained for a long time.

(Other embodiments)
The invention is not limited to the embodiments described above.
In the above embodiment, the film has the counter electrode side moisture-proof film. However, the present invention is not limited to this, and may not have the counter electrode side moisture-proof film. However, from the viewpoint of further preventing infiltration of water into the electrolytic solution 14, it is preferable to have a counter electrode side moisture-proof film.

  In the above embodiment, the first moisture-proof layer (photoelectrode-side barrier layer) having transparency is provided on the surface of the photoelectrode. However, the present invention is not limited to this. When the surface of the counter electrode is a light receiving surface, the counter electrode side barrier layer is a first moisture-proof layer (a moisture-proof layer having transparency).

In the above embodiment, the photoelectrode-side adhesive layer is provided. However, the present invention is not limited to this, and may not have the photoelectrode-side adhesive layer. In this case, the photoelectrode-side adhesive layer and the photoelectrode support may be brought into close contact with each other by heat fusion or the like.
Similarly, the counter electrode side adhesive layer may not be provided.

(Examples 1 to 6, Comparative Examples 1 to 3)
According to the composition of Table 1, a sensitizing dye (ruthenium-based dye) and water were dispersed in a dye solution dispersion medium (a mixed organic solvent) to prepare a dye solution.
A photoelectrode precursor having a photoelectrode support (PEN), a photoelectrode conductive layer (ITO), and an inorganic semiconductor layer (titanium oxide) in this order was prepared. This photoelectric precursor had seven inorganic semiconductor layers 26 mm wide and 250 mm long. The seven inorganic semiconductor layers were arranged in a direction orthogonal to the length of the inorganic semiconductor layer.
The photoelectrode precursor was immersed in the dye dispersion. The immersion time was 18 hours. The immersion temperature was room temperature (25 ° C.). Thereafter, the photoelectrode precursor was taken out of the dye solution, and the photoelectrode precursor was washed with a dye solution dispersion medium. The washed photoelectrode precursor was dried to obtain a photoelectrode film.
The “balance” of the dye solution dispersion medium in the table is an amount necessary to make the whole 1 L.

  An adhesive containing conductive particles having a thickness of 50 μm was applied between the inorganic semiconductor layers in the photoelectrode film of each example along the inorganic semiconductor layers. Thereby, it was divided into seven cells. A sealing material was applied on both sides of the adhesive along the applied adhesive. The counter electrode film was overlaid on the applied sealing material, and the sealing material was cured. The counter electrode film was a film with a platinum coating (counter electrode conductive layer). The electrolyte was injected into each of the seven cells. Both ends of the cell in the longitudinal direction were melt-pressed to obtain DSC of each example. Each cell of the obtained DSC had a width of 26 mm and a length of 250 mm. Also, the seven cells were connected in series.

  The moisture-proof layer shown in Table 1 was adhered to both surfaces of the DSC of each example with an adhesive composition (synthetic rubber) to obtain a DSC with a protective layer. The output of the obtained DSC with a protective layer was measured, and the results are shown in Table 1.

(Evaluation methods)
<Output measurement>
The output (initial output) at a light quantity of 200 lux in each example of the DSC with the protective layer (immediately after production) was measured by an evaluation device connected to a solar simulator and an IV characteristic measuring device. The DSC with a protective layer of each example was stored in a constant temperature room at a humidity of 90% RH and a temperature of 60 ° C. for 20 days. The output (output after storage) of the DSC with the protective layer after storage in the constant temperature room was measured in the same manner as the initial output.
The output maintenance ratio was determined by the following equation (1). It can be evaluated that the higher the output maintenance ratio, the longer the DSC performance can be maintained.

  Output maintenance rate (%) = output after storage / initial output x 100 (1)

<Peel strength>
From the DSC of each example, a laminate of the photoelectrode film, the adhesive layer, and the moisture-proof layer was cut out to obtain a sample. The sample was 15 mm wide × 100 mm long. At the end of the sample, the photoelectrode film and the moisture-proof layer were opened at 180 ° and held, and a peeling test was performed at a load speed of 300 mm / min. After the start of peeling, the first 15 mm was excluded from the measurement target, and the maximum load was measured.

As shown in Table 1, in Examples 1 to 6 to which the present invention was applied, the initial output was 3.8 μW / cm ² or more, and the output maintenance ratio was 79% or more.
In Comparative Example 1 in which the water content in the electrolyte was less than the lower limit of the present invention, the initial output was low.
In Comparative Example 2 in which the water content in the electrolytic solution was more than the upper limit of the present invention, the initial output was low and the output maintenance ratio was low. Comparative Example 3 in which the moisture-proof layer did not have a water vapor barrier property had a low output maintenance ratio.

Reference Signs List 1 dye-sensitized solar cell with protective layer, 2 protective layer, 10 dye-sensitized solar cell, 12 inorganic semiconductor layer, 14 electrolyte, 21 photoelectrode support, 22 counter electrode support, 31 photoelectrode conductive layer, 32 Counter electrode conductive layer, 41 Photo electrode, 42 Counter electrode, 44 Power generation unit, 81 Photo electrode side moisture proof film, 82 Counter electrode side moisture proof film, 83 Photo electrode side barrier layer, 84 Photo electrode side adhesive layer, 85 Counter electrode side Barrier layer, 86 opposing electrode side adhesive layer

Claims (6)

A first conductive substrate, a second conductive substrate opposed to the first conductive substrate, between the first conductive substrate and the second conductive substrate Having at least one power generation unit, and a dye-sensitized solar cell having a surface of the first conductive substrate as a light-receiving surface;
Having a first moisture-proof layer covering the surface of the first conductive substrate,
The power generation unit has an inorganic semiconductor layer and an electrolyte,
The water content of the electrolytic solution is 100 to 8000 mass ppm with respect to the total mass of the electrolytic solution,
The first moisture-proof layer is a dye-sensitized solar cell with a protective layer having a light-transmitting property.   The dye-sensitized solar cell with a protective layer according to claim 1, wherein the peel strength between the first conductive substrate and the first moisture-proof layer is 8 to 15 N / cm. Further comprising a first adhesive layer located between the first moisture-proof layer and the first conductive substrate,
3. The dye-sensitized solar cell with a protective layer according to claim 1, wherein the first adhesive layer has a water vapor transmission rate of 0 to 200 g / m ² / day. 4.   The dye-sensitized solar cell with a protective layer according to any one of claims 1 to 3, further comprising a second moisture-proof layer covering a surface of the second conductive substrate.   The dye-sensitized solar cell with a protective layer according to claim 4, wherein the peel strength between the second conductive substrate and the second moisture-proof layer is 8 to 15 N / cm. Further comprising a second adhesive layer located between the second moisture-proof layer and the second conductive substrate,
The dye-sensitized solar cell with a protective layer according to claim 4 or 5, wherein the second adhesive layer has a water vapor transmission rate of 0 to 200 g / m ² / day.

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