JP2018037554A - Photoelectric conversion element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element having superior durability.SOLUTION: A photoelectric conversion element comprises at least one photoelectric conversion cell. The at least one photoelectric conversion cell includes: an electrode substrate; a counter substrate opposed to the electrode substrate; an oxide semiconductor layer provided on the electrode substrate or counter substrate; a pigment adsorbed by the oxide semiconductor layer; an annular sealing part bonding the electrode substrate and the counter substrate to each other, and surrounding the oxide semiconductor layer; and an electrolyte arranged in a cell space formed by the electrode substrate, the counter substrate and the sealing part. The sealing part includes oxygen-absorbing particles.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a photoelectric conversion element.

  As a photoelectric conversion element, since it is inexpensive and high photoelectric conversion efficiency is obtained, a photoelectric conversion element using a dye has been attracting attention, and various developments have been made on photoelectric conversion elements using a dye.

  As a photoelectric conversion element using such a dye, for example, a dye-sensitized solar cell described in Patent Document 1 below is known. In the following Patent Document 1, two electrode substrates facing each other, an annular sealing portion that joins the two electrode substrates, and a cell space formed by the two electrode substrates and the sealing portion are arranged. And a sealing portion provided on the outer side of the electrolyte solution layer and a gas-resistant layer for suppressing gas permeation. A sensitized solar cell is disclosed.

JP 2007-294387 A

  However, the dye-sensitized solar cell described in Patent Document 1 described above has room for improvement in terms of durability.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a photoelectric conversion element having excellent durability.

  This inventor examined the cause which the said subject arises in the dye-sensitized solar cell of the said patent document 1. FIG. As a result, in the dye-sensitized solar cell described in Patent Document 1, since the gas-resistant permeation layer is in contact with the outside air, oxygen gas is easily absorbed, and the oxygen absorption capacity reaches a saturated state at an early stage. The present inventor thought that oxygen existing outside the stop portion easily penetrates into the electrolyte through the sealing portion, and as a result, the power generation performance of the photoelectric conversion element starts to deteriorate early. Therefore, as a result of further earnest research, the present inventor has found that the above-described problems can be solved by the following invention.

  That is, the present invention includes at least one photoelectric conversion cell, and the photoelectric conversion cell includes an electrode substrate, a counter substrate facing the electrode substrate, and an oxide semiconductor layer provided on the electrode substrate or the counter substrate. A dye adsorbed on the oxide semiconductor layer, an annular sealing portion that joins the electrode substrate and the counter substrate and surrounds the oxide semiconductor layer, the electrode substrate, the counter substrate, and the sealing And an electrolyte disposed in the cell space formed by the stop portion, wherein the sealing portion contains oxygen-absorbing particles.

  According to the photoelectric conversion element of the present invention, the sealing portion contains oxygen absorbing particles. That is, the oxygen absorbing particles are present in the sealing portion. For this reason, the oxygen which penetrates from the outside of the sealing portion is sufficiently absorbed by the oxygen absorbing particles. For this reason, compared with the case where the sealing part does not contain oxygen-absorbing particles, it is sufficiently suppressed that oxygen penetrates the sealing part from the outside of the sealing part and enters the electrolyte. Moreover, since the oxygen absorbing particles are contained in the form of particles in the sealing portion, the oxygen absorbing particles are sufficiently suppressed from coming into contact with the outside air. For this reason, the time until the oxygen absorption capacity of the oxygen-absorbing particles reaches a saturated state is extended, and the power generation performance of the photoelectric conversion element is sufficiently suppressed from starting to deteriorate at an early stage. Therefore, the photoelectric conversion element of the present invention can have excellent durability.

  In the said photoelectric conversion element, it is preferable that the said oxygen absorption particle is unevenly distributed in the said sealing part.

  Thus, when the oxygen absorbing particles are unevenly distributed in the sealing portion, the sealing portion has a portion with a high content of oxygen absorbing particles and a portion with a low content of oxygen absorbing particles. Here, the portion with a small content of oxygen-absorbing particles in the sealing portion has better adhesion to the electrode substrate and the counter substrate than the portion with a large content of oxygen-absorbing particles in the sealing portion. Have. Therefore, compared with the case where the content rate of oxygen-absorbing particles is large throughout the sealing portion and the oxygen-absorbing particles are uniformly present, the entire sealing portion has better adhesion to the electrode substrate and the counter substrate. Have Therefore, the photoelectric conversion element of the present invention has more excellent durability.

  In the photoelectric conversion element, the sealing portion joins the electrode substrate and the counter substrate, and includes an annular oxygen-absorbing particle-containing portion containing the oxygen-absorbing particles, and an inner side than the oxygen-absorbing particle-containing portion. It is preferable that the content rate of the oxygen absorbing particles in the oxygen absorbing particle containing portion is greater than the content rate of the oxygen absorbing particles in the inner portion.

  In this case, oxygen that enters from the outside of the sealing portion is sufficiently absorbed by the oxygen-absorbing particle-containing portion, so that oxygen can be sufficiently prevented from entering the electrolyte. In addition, the oxygen absorbing particle-containing portion is moved away from the electrolyte, so that the oxygen absorbing particle-containing portion is away from the electrolyte, so that the oxygen absorbing particle-containing portion is provided inside the oxygen absorbing particle-containing portion. Absorption by the oxygen-absorbing particles in the oxygen-absorbing particle-containing portion is sufficiently suppressed, so that the time until the oxygen-absorbing performance of the oxygen-absorbing particles in the oxygen-absorbing particle-containing portion reaches a saturated state is extended. For this reason, the time until the oxygen absorption performance reaches a saturated state as the whole sealing portion is extended. For this reason, the photoelectric conversion element of this invention has the further outstanding durability.

  In the said photoelectric conversion element, the said sealing part further has the cyclic | annular outer side part provided outside the said oxygen absorption particle content part, The content rate of the said oxygen absorption particle in the said oxygen absorption particle content part is It is preferable that the content rate of the oxygen-absorbing particles in the outer portion is larger.

  In this case, the oxygen-absorbing particle-containing portion is located outside the oxygen-absorbing particle-containing portion, and the oxygen-absorbing particle-containing portion is kept away from the outside air, so that the oxygen-absorbing particle-containing portion is smaller than the oxygen-absorbing particle-containing portion. The time until the oxygen absorption performance of the oxygen-absorbing particles in the part reaches a saturated state is extended. For this reason, the time until the oxygen absorption performance reaches a saturated state as the whole sealing portion is extended. For this reason, the photoelectric conversion element of this invention has the further outstanding durability.

  According to the present invention, a photoelectric conversion element having excellent durability is provided.

It is sectional drawing which shows 1st Embodiment of the photoelectric conversion element of this invention. It is sectional drawing which shows 2nd Embodiment of the photoelectric conversion element of this invention. It is sectional drawing which shows 3rd Embodiment of the photoelectric conversion element of this invention.

  Hereinafter, a preferred embodiment of the photoelectric conversion element of the present invention will be described in detail with reference to FIG. FIG. 1 is a cross-sectional view showing a first embodiment of the photoelectric conversion element of the present invention.

  As shown in FIG. 1, the photoelectric conversion element 100 includes one photoelectric conversion cell 60. The photoelectric conversion cell 60 includes an electrode substrate 10, a counter substrate 20 facing the electrode substrate 10, an oxide semiconductor layer 30 provided on the electrode substrate 10, a dye adsorbed on the oxide semiconductor layer 30, and an electrode substrate. 10 and the annular sealing part 40 which joins the counter substrate 20, and the electrolyte 50 arrange | positioned in the cell space formed of the electrode substrate 10, the counter substrate 20, and the sealing part 40.

  The electrode substrate 10 includes a transparent substrate 11 and a transparent conductive layer 12 provided on the transparent substrate 11.

  The counter substrate 20 includes a conductive substrate 21 that also serves as a substrate and an electrode, and a conductive catalyst layer 22.

  The sealing portion 40 joins the electrode substrate 10 and the counter substrate 20, and includes an annular oxygen-absorbing particle-containing portion 42 that contains oxygen-absorbing particles, and an annular inner portion that is provided inside the annular oxygen-absorbing particle-containing portion 42. 41 and an annular outer portion 43 provided outside the annular oxygen-absorbing particle-containing portion 42. Here, the oxygen-absorbing particle-containing part 42 contains a sealing material and oxygen-absorbing particles 40a having oxygen absorbing ability, and both the inner part 41 and the outer part 43 contain at least a sealing material. And the content rate R2 (volume%) of the oxygen absorption particles 40a in the oxygen absorption particle content part 42 is larger than the content rate R1 (volume%) of the oxygen absorption particles 40a in the inner part 41, and in the outer part 43 It is larger than the content rate R3 (volume%) of the oxygen absorbing particles 40a. That is, in the sealing part 40, the oxygen absorption particles 40a are unevenly distributed.

  According to the photoelectric conversion element 100, the sealing part 40 contains the sealing material and the oxygen absorbing particles 40a. That is, the oxygen absorbing particles 40 a are present in the sealing part 40. For this reason, oxygen that enters from the outside of the sealing portion 40 is sufficiently absorbed by the oxygen absorbing particles 40a. For this reason, compared with the case where the sealing part 40 does not contain the oxygen absorbing particles 40a, it is sufficient that oxygen penetrates the sealing part 40 from the outside of the sealing part 40 and enters the electrolyte 50. It is suppressed. Further, since the oxygen absorbing particles 40a are included in the sealing portion 40 in the form of particles, the oxygen absorbing particles 40a are sufficiently suppressed from coming into contact with the outside air. For this reason, time until the oxygen absorption ability of the oxygen absorption particle 40a reaches a saturation state is extended, and it is sufficiently suppressed that the power generation performance of the photoelectric conversion element 100 starts to deteriorate at an early stage. Therefore, the photoelectric conversion element 100 can have excellent durability.

  Further, in the photoelectric conversion element 100, the oxygen absorbing particles 40 a are unevenly distributed in the sealing portion 40. Specifically, the sealing portion 40 includes an oxygen-absorbing particle-containing portion 42 having a large content of oxygen-absorbing particles 40a, and an inner portion 41 and an outer portion 43 having a small content of oxygen-absorbing particles 40a. Here, the inner portion 41 and the outer portion 43 having a small content rate of the oxygen absorbing particles 40a in the sealing portion 40 are compared with the oxygen absorbing particle containing portion 42 having a large content rate of the oxygen absorbing particles 40a in the sealing portion 40. Thus, it has better adhesion to the electrode substrate 10 and the counter substrate 20. Therefore, compared with the case where the content rate of the oxygen absorbing particles 40a is large over the entire sealing portion 40 and the oxygen absorbing particles 40a are uniformly present, the entire sealing portion 40 is in relation to the electrode substrate 10 and the counter substrate 20. , Have better adhesion. Therefore, the photoelectric conversion element 100 has more excellent durability.

  Furthermore, in the photoelectric conversion element 100, the content R2 of the oxygen absorbing particles 40a in the oxygen absorbing particle containing portion 42 is larger than the content R1 of the oxygen absorbing particles 40a in the inner portion 41. For this reason, oxygen that enters from the outside of the sealing portion 40 is sufficiently absorbed by the oxygen-absorbing particle-containing portion 42, and thus oxygen is sufficiently suppressed from entering the electrolyte 50. Further, the oxygen absorbing particle-containing portion 42 is moved away from the electrolyte 50 because the inner portion 41 in which the content rate of the oxygen absorbing particles 40 a is smaller than that of the oxygen absorbing particle-containing portion 42 is provided inside the oxygen absorbing particle-containing portion 42. In addition, since oxygen in the electrolyte 40 is sufficiently suppressed from being absorbed by the oxygen absorbing particles in the oxygen absorbing particle containing portion 42, the oxygen absorbing performance of the oxygen absorbing particles 40a in the oxygen absorbing particle containing portion 42 is saturated. The time to reach is extended. For this reason, the time until the oxygen absorption performance reaches a saturated state as the whole sealing portion 40 is extended. For this reason, the photoelectric conversion element 100 has much more excellent durability.

  Further, in the photoelectric conversion element 100, the content R2 of the oxygen absorbing particles 40a in the oxygen absorbing particle containing portion 42 is larger than the content R3 of the oxygen absorbing particles 40a in the outer portion 43. For this reason, the oxygen absorbing particle-containing portion 42 is kept away from the outside air by the amount of the outer portion 43 in which the content of the oxygen absorbing particles 40a is smaller than that of the oxygen absorbing particle-containing portion 42 outside the oxygen absorbing particle-containing portion 42. The time until the oxygen absorbing performance of the oxygen absorbing particles 40a in the oxygen absorbing particle containing portion 42 reaches a saturated state is extended. For this reason, time until oxygen absorption performance is saturated also as the whole sealing part 40 extends. For this reason, the photoelectric conversion element 100 has much more excellent durability.

  Next, the electrode substrate 10, the counter substrate 20, the oxide semiconductor layer 30, the dye, the sealing portion 40, and the electrolyte 50 will be described in detail.

<Electrode substrate>
As described above, the electrode substrate 10 includes the transparent substrate 11 and the transparent conductive layer 12 provided on the transparent substrate 11.

  The material which comprises the transparent substrate 11 should just be a transparent material, for example, As such a transparent material, glass, such as borosilicate glass, soda lime glass, white plate glass, quartz glass, polyethylene terephthalate (PET), for example Insulating materials such as polyethylene naphthalate (PEN), polycarbonate (PC), and polyethersulfone (PES). The thickness of the transparent substrate 11 is appropriately determined according to the size of the photoelectric conversion element 100 and is not particularly limited, but may be in a range of 0.05 to 40 mm, for example.

Examples of the material constituting the transparent conductive layer 12 include conductive metal oxides such as tin-added indium oxide (ITO), tin oxide (SnO ₂ ), and fluorine-added tin oxide (FTO). The transparent conductive layer 12 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductive layer 12 is composed of a single layer, the transparent conductive layer 12 is preferably composed of FTO because it has high heat resistance and chemical resistance. The thickness of the transparent conductive layer 12 may be in the range of 0.01 to 2 μm, for example.

<Counter substrate>
As described above, the counter substrate 20 includes the conductive substrate 21 serving as a substrate and an electrode, and the conductive catalyst layer 22.

  The conductive substrate 21 is made of a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, tungsten, aluminum, and stainless steel. The conductive substrate 21 may be formed of a laminate in which a substrate and an electrode are separated and a transparent conductive layer made of a conductive oxide such as ITO or FTO is formed as an electrode on the above-described insulating transparent substrate. The thickness of the conductive substrate 21 is appropriately determined according to the size of the photoelectric conversion element 100 and is not particularly limited, but may be, for example, 5 to 4000 μm.

  The catalyst layer 22 is composed of platinum, a carbon-based material, a conductive polymer, or the like. Here, carbon nanotubes are suitably used as the carbon-based material. Note that the counter substrate 20 may not have the catalyst layer 22 when the conductive substrate 21 has a catalytic function (for example, when carbon is included).

<Oxide semiconductor layer>
The oxide semiconductor layer 30 is composed of oxide semiconductor particles. Examples of the oxide semiconductor particles include titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), zinc oxide (ZnO), tungsten oxide (WO ₃ ), niobium oxide (Nb ₂ O ₅ ), and strontium titanate (SrTiO ₃ ). , Tin oxide (SnO ₂ ), or two or more thereof.

<Dye>
Examples of the dye include a photosensitizing dye such as a ruthenium complex having a ligand containing a bipyridine structure, a terpyridine structure, or the like, an organic dye such as porphyrin, eosin, rhodamine, or merocyanine, and an organic- Examples include inorganic composite dyes. For example, CH ₃ NH ₃ PbX ₃ (X = Cl, Br, I) is used as the lead halide perovskite. Here, when a photosensitizing dye is used as the dye, the photoelectric conversion element 100 is a dye-sensitized photoelectric conversion element, and the photoelectric conversion cell 60 is a dye-sensitized photoelectric conversion cell.

  Among the above dyes, a photosensitizing dye composed of a ruthenium complex having a ligand containing a bipyridine structure or a terpyridine structure is preferable. In this case, the photoelectric conversion characteristics of the photoelectric conversion element 100 can be further improved.

<Sealing part>
The sealing part 40 contains the sealing material and the oxygen absorbing particles 40a as described above.

  The sealing material is not particularly limited, and examples thereof include thermoplastic resins such as modified polyolefin resins and vinyl alcohol polymers, and resins such as ultraviolet curable resins. Examples of the modified polyolefin resin include ionomer, maleic anhydride-modified polyolefin, ethylene-vinyl acetic anhydride copolymer, ethylene-methacrylic acid copolymer, and ethylene-vinyl alcohol copolymer. Among these, modified polyolefin resin is preferable. In this case, the adhesion to the electrode substrate 10 and the counter substrate 20 is further increased.

  As described above, the sealing part 40 includes the inner part 41, the oxygen-absorbing particle-containing part 42, and the outer part 43, but the sealing material in the inner part 41, the oxygen-absorbing particle-containing part 42 and the outer part 43. May be made of different materials or may be made of the same material.

  However, it is preferable that the sealing material in the inner portion 41 is made of a material having low permeability of the electrolyte 40 and having durability with respect to the electrolyte 40. An example of such a sealing material is maleic anhydride-modified polyolefin resin.

  On the other hand, the sealing material in the outer portion 43 and the oxygen-absorbing particle-containing portion 42 is preferably composed of a material having a lower oxygen permeability coefficient than the sealing material of the inner portion 41. Examples of such a sealing material include an ethylene-vinyl alcohol copolymer and a vinyl alcohol polymer.

  The oxygen-absorbing particles 40a are not particularly limited as long as the oxygen-absorbing particles 40a have higher oxygen absorbability than the sealing material. Examples of the oxygen absorbing particles 40a include cerium-based oxygen absorbing particles, iron-based oxygen absorbing particles, cobalt-based oxygen absorbing particles, and organic oxygen-absorbing particles. Of these, cerium-based oxygen-absorbing particles are preferred because no moisture is required for the oxygen-absorbing reaction.

  Examples of the cerium-based oxygen absorbing particles include cerium oxide.

  Examples of the iron-based oxygen absorbing particles include reduced iron powder.

  Examples of the cobalt-based oxygen absorbing particles include cobalt naphthenate.

  Examples of organic oxygen absorbing particles include ascorbic acids.

  The difference (R2−R1) between the content R2 (volume%) of the oxygen absorbing particles 40a in the oxygen absorbing particle containing part 42 and the content R1 (volume%) of the oxygen absorbing particles 40a in the inner part 41 is 2 volumes. % Or more is preferable. In this case, the adhesiveness of the inner portion 41 to the electrode substrate 10 and the counter substrate 20 can be further improved than the adhesiveness of the oxygen-absorbing particle-containing portion 42 to the electrode substrate 10 and the counter substrate 20. (R2-R1) is more preferably 10% by volume or more. It is particularly preferable that the inner portion 41 does not contain oxygen absorbing particles. In this case, the adhesiveness of the inner portion 41 with respect to the electrode substrate 10 and the counter substrate 20 can be further improved than the adhesiveness of the oxygen-absorbing particle-containing portion 42 with respect to the electrode substrate 10 and the counter substrate 20.

  The difference (R2−R3) between R2 and the content R3 (volume%) of the oxygen absorbing particles 40a in the outer portion 43 is preferably 2% by volume or more. In this case, the adhesion of the outer portion 43 to the electrode substrate 10 and the counter substrate 20 can be further improved than the adhesion of the oxygen-absorbing particle-containing portion 42 to the electrode substrate 10 and the counter substrate 20. (R2-R3) is preferably 10% by volume or more. It is particularly preferable that the outer portion 43 does not contain oxygen absorbing particles. In this case, the adhesion of the outer portion 43 to the electrode substrate 10 and the counter substrate 20 can be further improved than the adhesion of the oxygen-absorbing particle-containing portion 42 to the electrode substrate 10 and the counter substrate 20.

  R1 and R3 may be the same or different.

  R2 is not particularly limited as long as it is larger than R1 and R3, but it is preferably 2% by volume or more. In this case, oxygen entering from the outside of the sealing portion 40 is sufficiently absorbed by the oxygen absorbing particles 40a. For this reason, the durability of the photoelectric conversion element 100 can be further improved. R2 is preferably 10% by volume or more. However, R2 is preferably 90% by volume or less. In this case, the adhesion of the oxygen-absorbing particle-containing portion 42 to the electrode substrate 10 and the counter substrate 20 can be further improved. R2 is preferably 50% by volume or less.

<Electrolyte>
The electrolyte 50 includes, for example, a redox couple and an organic solvent. As the organic solvent, acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, valeronitrile and the like can be used. Examples of the redox pair include a redox pair containing a halogen atom such as iodide ion / polyiodide ion (for example, I ⁻ / I ₃ ⁻ ), bromide ion / polybromide ion, zinc complex, iron complex, cobalt complex, and the like. And redox pairs. The iodide ion / polyiodide ion can be formed by iodine (I ₂ ) and a salt (ionic liquid or solid salt) containing iodide (I ⁻ ) as an anion. When using an ionic liquid having an iodide as an anion, only iodine should be added. When using an ionic liquid other than an organic solvent or an anion as an anion, an anion such as LiI or tetrabutylammonium iodide is used. A salt containing iodide (I ⁻ ) may be added.

  The electrolyte 50 may be an ionic liquid instead of the organic solvent. As the ionic liquid, for example, a known iodine salt such as a pyridinium salt, an imidazolium salt, or a triazolium salt, and a room temperature molten salt that is in a molten state near room temperature is used. Examples of such room temperature molten salts include 1-hexyl-3-methylimidazolium iodide, 1-ethyl-3-propylimidazolium iodide, 1-ethyl-3-methylimidazolium iodide, 1, 2 -Dimethyl-3-propylimidazolium iodide, 1-butyl-3-methylimidazolium iodide, or 1-methyl-3-propylimidazolium iodide is preferably used.

  The electrolyte 50 may be a mixture of the ionic liquid and the organic solvent instead of the organic solvent.

  An additive can be added to the electrolyte 50. Examples of the additive include LiI, 4-t-butylpyridine, guanidinium thiocyanate, 1-methylbenzimidazole, 1-butylbenzimidazole and the like.

Furthermore, as the electrolyte 50, a nanocomposite gel electrolyte which is a pseudo-solid electrolyte obtained by kneading nanoparticles such as SiO ₂ , TiO ₂ , and carbon nanotubes with the above electrolyte may be used, and polyvinylidene fluoride may be used. Alternatively, an electrolyte gelled with an organic gelling agent such as a polyethylene oxide derivative or an amino acid derivative may be used.

  The present invention is not limited to the above embodiment. For example, in the said embodiment, although the sealing part 40 which comprises the photoelectric conversion cell 60 is comprised by the inner part 41, the oxygen absorption particle containing part 42, and the outer part 43, like the photoelectric conversion element 200 shown in FIG. Moreover, the sealing part 240 which comprises the photoelectric conversion cell 260 may be comprised only by the inner side part 41 and the oxygen absorption particle containing part 42. FIG. That is, the sealing part 240 may not have the outer part 43.

  Moreover, in the said embodiment, although the sealing part 40 which comprises the photoelectric conversion cell 60 is comprised by the inner side part 41, the oxygen absorption particle containing part 42, and the outer side part 43, a sealing part is the oxygen absorption particle containing part 42. And the outer portion 43 alone.

  Moreover, in the said embodiment, although the oxygen absorption particle 40a is unevenly distributed in the sealing parts 40 and 240, the oxygen absorption particle 40a does not need to be unevenly distributed in the sealing parts 40 and 240. FIG. The oxygen absorbing particles 40a may exist uniformly in the sealing portions 40 and 240. For example, like the photoelectric conversion element 300 shown in FIG. 3, the sealing part 340 that constitutes the photoelectric conversion cell 360 may be configured only by the oxygen-absorbing particle-containing part 42.

  Furthermore, in the said embodiment, although the photoelectric conversion elements 100, 200, 300 each have only one photoelectric conversion cell, the photoelectric conversion elements 100, 200, 300 may include a plurality of photoelectric conversion cells. . Here, the plurality of photoelectric conversion cells may be connected in series or may be connected in parallel.

  Furthermore, in the said embodiment, the oxide semiconductor layer 30 is provided on the transparent conductive layer 12 of the electrode substrate 10, and the photoelectric conversion elements 100, 200, and 300 have a structure where light reception is performed from the electrode substrate 10 side. However, when a laminate (transparent material) in which a transparent conductive layer made of a conductive oxide such as ITO or FTO is formed as an electrode on the transparent substrate 11 as the conductive substrate 21 constituting the counter substrate 20 is used, an oxidation is performed. Instead of the transparent substrate 11, an opaque material (for example, a metal substrate) may be used as a base material on which the physical semiconductor layer 30 is provided, and light reception may be performed from the counter substrate 20 side. Furthermore, when using the laminated body (transparent material) which formed the transparent conductive layer which consists of conductive oxides, such as ITO and FTO, as the electrode in the transparent substrate 11 as the conductive substrate 21 which comprises the opposing substrate 20, The photoelectric conversion elements 100, 200, and 300 have a structure in which light is received from both the electrode substrate 10 and the counter substrate 20.

  Further, in the above embodiment, the oxide semiconductor layer 30 is provided on the electrode substrate 10, but the oxide semiconductor layer 30 may be provided on the conductive substrate 21 of the counter substrate 20. However, in this case, the catalyst layer 22 is provided on the transparent conductive layer 12.

  Furthermore, in the said embodiment, although the opposing board | substrate 20 is comprised with the electroconductive board | substrate 21 and the catalyst layer 22, the opposing board | substrate 20 may be comprised with an insulating substrate. As the insulating substrate, for example, a glass substrate or a resin film can be used. However, in this case, a counter electrode is provided on the oxide semiconductor layer 30. Here, the counter electrode can be the same as the counter substrate 20. Alternatively, the counter electrode may be composed of a single porous layer containing, for example, carbon. A porous insulating layer is provided between the oxide semiconductor layer 30 and the counter electrode. The porous insulating layer is mainly for impregnating the electrolyte 40 inside. As such a porous insulating layer, for example, an oxide fired body can be used. Note that the porous insulating layer may be provided between the electrode substrate 10 and the counter electrode so as to surround the oxide semiconductor layer 30.

  Hereinafter, the content of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.

Example 1
First, an oxide semiconductor layer was formed on an electrode substrate (trade name “TECa7”, manufactured by Pilkington) on which a transparent conductive layer made of FTO was formed on glass. As the oxide semiconductor layer, an oxide semiconductor layer forming paste (trade name “PST-21NR”, manufactured by JGC Catalysts & Chemicals Co., Ltd.) is prepared, and this paste is baked on the transparent conductive layer of the electrode substrate by screen printing. After printing to a thickness of 9 μm and drying, it was formed by baking at 500 ° C. for 30 minutes. Thus, a structure was obtained.

  Next, the dye was adsorbed to the oxide semiconductor layer by immersing the structure in the dye solution for 16 hours. At this time, a 0.2 mM Z907 dye solution was used as the dye solution.

  Next, an electrolyte was dropped on the oxide semiconductor layer of the structure. As the electrolyte, a solution in which iodine was dissolved to 10 mM in a solvent composed of methoxypropionitrile was used.

  On the other hand, a counter electrode as a counter substrate was prepared by forming a catalyst layer made of platinum having a thickness of 10 nm on a titanium foil having a thickness of 40 μm by a sputtering method. At this time, on the surface of the titanium foil, masking was performed so that the catalyst layer was not formed on the peripheral portion where the sealing portion was to be formed.

  Next, an annular inner part, an annular oxygen-absorbing particle-containing part, and an annular outer part were prepared. At this time, a resin film having a dimension of 54 mm × 54 mm × 50 μm made of maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont) is prepared for the inner part, and a dimension of 53 mm × 53 mm is prepared on this film. It was prepared by forming one opening having The oxygen-absorbing particle-containing part was prepared by kneading oxygen-absorbing particles (made by Mitsui Kinzoku Co., Ltd.) made of a cerium-based oxygen absorbent into maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont). A film having a size of × 50 μm was prepared, and one opening having a size of 54 mm × 54 mm was formed in the film. At this time, the film was formed so that the content of oxygen-absorbing particles was 50% by volume. A resin film having a dimension of 56 mm × 56 mm × 50 μm made of maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont) is prepared for the outer side, and the film has a dimension of 55 mm × 55 mm. Prepared by forming two openings. And after arrange | positioning the cyclic | annular oxygen absorption particle containing part in the peripheral part in which the catalyst layer is not formed into the titanium foil of a counter substrate, the cyclic | annular inner part and cyclic | annular outer part are arrange | positioned in the inner side and the outer side, respectively. And bonded by a heat laminating method. Thus, a counter substrate on which a sealing portion was formed was prepared.

  Then, in a vacuum chamber with a vacuum degree of 600 Pa, the counter substrate on which the sealing portion is formed is superposed on the structure to which the electrolyte is dropped, and a stepped heat is formed by providing an annular protrusion on the plate-like main body portion. The electrode substrate and the counter substrate were joined by using a mold and heating and melting the pressurizing portion while pressing the sealing portion so that the surface temperature of the protruding portion was 200 ° C. At this time, pressurization was performed with a press thrust of about 1 kN. Moreover, the thickness of the sealing part became 50 micrometers.

  As described above, a photoelectric conversion element composed of one photoelectric conversion cell was obtained.

(Example 2)
When the sealing portion is formed on the counter substrate, the outer portion is not used, and the sealing portion is formed using only the annular inner portion and the annular oxygen-absorbing particle-containing portion. A conversion element was produced.

  At this time, the annular inner portion and the annular oxygen-absorbing particle-containing portion were prepared as follows. That is, a resin film having a dimension of 54.5 mm × 54.5 mm × 50 μm made of maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont) is prepared for the annular inner portion. It was prepared by forming one opening having a size of 53 mm × 53 mm. Further, the cyclic oxygen-absorbing particle-containing part is obtained by kneading oxygen-absorbing particles (made by Mitsui Kinzoku Co., Ltd.) made of a cerium-based oxygen absorbent into maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont). A film having a size of 56 mm × 56 mm × 50 μm was prepared, and one opening having a size of 54.5 mm × 54.5 mm was formed in the film. At this time, the film was formed so that the content of oxygen-absorbing particles was 50% by volume.

(Example 3)
When forming the sealing portion on the counter substrate, the photoelectric conversion element was obtained in the same manner as in Example 1 except that the sealing portion was formed using only the annular oxygen-absorbing particle-containing portion without using the inner and outer portions. Was made.

  At this time, the annular oxygen-absorbing particle-containing part was prepared as follows. That is, the cyclic oxygen-absorbing particle-containing part is obtained by kneading oxygen-absorbing particles (made by Mitsui Kinzoku Co., Ltd.) made of a cerium-based oxygen absorbent into maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont). A film having a size of 56 mm × 56 mm × 50 μm was prepared, and one opening having a size of 53 mm × 53 mm was formed in the film. At this time, the film was formed so that the content of oxygen-absorbing particles was 50% by volume.

(Comparative Example 1)
When forming the sealing portion on the counter substrate, the photoelectric conversion element is the same as in Example 1 except that the sealing portion is formed using only the annular inner portion without using the oxygen absorbing particle-containing portion and the outer portion. Was made.

  At this time, the annular inner portion was prepared as follows. Specifically, a resin film having a dimension of 56 mm × 56 mm × 50 μm made of maleic anhydride-modified polyethylene resin (trade name “Bynel 4164”, manufactured by DuPont) is prepared for the annular inner portion, and 53 mm × 53 mm is prepared on this film. Prepared by forming one opening with dimensions.

<Power generation performance>
With respect to the photoelectric conversion elements of Examples 1 to 3 and Comparative Example 1 obtained as described above, an IV curve was measured in a state of being irradiated with white light of 200 lux immediately after production, and the maximum calculated from this IV curve. The output operating power Pm ₀ (μW) was calculated as “output 1”, and this was used as the initial power generation amount. The results are shown in Table 1. The light source, illuminance meter, and power source used for measuring the IV curve are as follows.

Light source: White LED (product name “LEL-SL5N-F”, manufactured by Toshiba Lighting & Technology Corp.)
Illuminance meter: Product name “Digital Illuminance Meter 51013”, Yokogawa Meter & Instruments Power Supply: Voltage / Current Generator (Product name “R6246I”, ADVANTEST)

<Durability>
The photoelectric conversion elements of Examples 1 to 3 and Comparative Example 1 were irradiated with 200 lux of white light for 4000 hours immediately after fabrication. At this time, every time 500 hours elapse, IV curves are measured for the photoelectric conversion elements of Examples 1 to 3 and Comparative Example 1, and the maximum output operating power PW (μW) for each time calculated from this IV curve is expressed as “ Calculated as “Output 2”. And the output maintenance factor was computed based on the following formula. The results are shown in Table 1.

Output maintenance rate = Output 2 / Output 1 x 100 (%)

  As shown in Table 1, the photoelectric conversion elements of Examples 1 to 3 did not start decreasing the output retention rate even after 1500 hours, whereas the photoelectric conversion elements of Comparative Example 1 were 500 hours. It was found that the output maintenance ratio began to decrease when the time elapsed. And even if 4000 hours passed, the photoelectric conversion element of Examples 1-3 showed the output maintenance factor of 85% or more, whereas the photoelectric conversion element of Comparative Example 1 had an output maintenance factor of 71%. It had dropped to.

  From the above results, it was confirmed that the photoelectric conversion element of the present invention has excellent durability.

DESCRIPTION OF SYMBOLS 10 ... Electrode substrate 20 ... Opposite substrate 30 ... Oxide semiconductor layer 40, 240, 340 ... Sealing part 40a ... Oxygen absorption particle 41 ... Inner part 42 ... Oxygen absorption particle containing part 43 ... Outer part 50 ... Electrolyte 60, 260, 360 ... Photoelectric conversion cell 100, 200, 300 ... Photoelectric conversion element

Claims (4)

Comprising at least one photoelectric conversion cell;
The photoelectric conversion cell is
An electrode substrate;
A counter substrate facing the electrode substrate;
An oxide semiconductor layer provided on the electrode substrate or the counter substrate;
A dye adsorbed on the oxide semiconductor layer;
An annular sealing portion that joins the electrode substrate and the counter substrate and surrounds the oxide semiconductor layer;
An electrolyte disposed in a cell space formed by the electrode substrate, the counter substrate, and the sealing portion;
The photoelectric conversion element in which the said sealing part contains oxygen absorption particle.   The photoelectric conversion element according to claim 1, wherein the oxygen absorbing particles are unevenly distributed in the sealing portion. The sealing portion is
The electrode substrate and the counter substrate are joined, and the oxygen-absorbing particle-containing portion containing the oxygen-absorbing particles,
An annular inner portion provided inside the oxygen-absorbing particle-containing portion,
3. The photoelectric conversion element according to claim 1, wherein a content rate of the oxygen absorbing particles in the oxygen absorbing particle containing portion is larger than a content rate of the oxygen absorbing particles in the inner portion. The sealing part further has an annular outer part provided outside the oxygen-absorbing particle-containing part,
The photoelectric conversion element according to claim 3, wherein a content rate of the oxygen absorbing particles in the oxygen absorbing particle-containing portion is larger than a content rate of the oxygen absorbing particles in the outer portion.

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