Patent Publication Number: US-2019180947-A1

Title: Photoelectric conversion element

Description:
TECHNICAL FIELD 
     The present invention relates to a photoelectric conversion element. 
     BACKGROUND 
     As a photoelectric conversion element, a photoelectric conversion element using dyes attracts attention since it is inexpensive and can obtain high photoelectric conversion efficiency, and various developments on photoelectric conversion elements using dyes are performed. 
     As the photoelectric conversion element using dyes, for example, a photoelectric conversion element described in the following patent document 1 is known. In the following patent document 1, disclosed is a photoelectric conversion element in which at least one photoelectric conversion cell includes: an electrode substrate; a counter substrate facing the electrode substrate; and a ring-shaped sealing portion bonding the electrode substrate and the counter substrate, and an electrolyte disposed inside the sealing portion. The following patent document 1 also discloses that the sealing portion includes a ring-shaped first resin sealing portion adhered to the electrode substrate, and a ring-shaped second resin sealing portion provided so as to sandwich the counter substrate together with the first resin sealing portion, and that the second resin sealing portion has a melting point higher than that of the first resin sealing portion. In this way, durability of the photoelectric conversion element is improved by providing a soft resin sealing portion between the electrode substrate and the counter substrate and relaxing the stress applied to an interface between the sealing portion and the electrode substrate or the counter substrate. 
     PATENT DOCUMENT 
     Patent document 1: International Publication No. 2012/118028 
     SUMMARY 
     However, the photoelectric conversion element described in the above patent document 1 still has room for improvement in terms of durability. 
     One or more embodiments of the present invention provide a photoelectric conversion element having excellent durability. 
     One or more embodiments of the present invention are directed to a photoelectric conversion element comprising at least one photoelectric conversion cell, wherein the photoelectric conversion cell includes: an electrode substrate; a counter substrate facing the electrode substrate; and a ring-shaped sealing portion bonding the electrode substrate and the counter substrate; and an electrolyte disposed inside the sealing portion, wherein the sealing portion includes: a ring-shaped first resin sealing portion bonded to the electrode substrate and containing a thermoplastic resin; and a ring-shaped second resin sealing portion provided so as to sandwich the counter substrate together with the first resin sealing portion and containing a thermoplastic resin, wherein the second resin sealing portion has a melting point higher than that of the first resin sealing portion, wherein the first resin sealing portion includes: a first main body part bonded to the electrode substrate; and a first protrusion part provided on a side of the first main body part facing the direction opposite to the electrode substrate, wherein the first main body part includes: an insertion part inserted between the electrode substrate and the counter substrate; and a non-insertion part which is not inserted between the electrode substrate and the counter substrate, wherein the first protrusion part is provided on the non-insertion part of the first main body part and the second resin sealing portion includes a second main body part provided on a side of the counter substrate facing the direction opposite to the electrode substrate and the second main body part of the second resin sealing portion is adhered to the first protrusion part. 
     According to one or more embodiments, when the photoelectric conversion element is placed under a high temperature environment, and a space between the counter substrate, the electrode substrate, and the sealing portion in the photoelectric conversion cell (hereinafter referred to as “cell space”) is pressurized, the counter substrate and the electrode substrate try to separate from each other. At this time, the sealing portion includes the first resin sealing portion having a melting point lower than that of the second resin sealing portion and the first resin sealing portion includes the insertion part inserted between the electrode substrate and the counter substrate. For this reason, even if an excessive stress is about to be applied in a direction perpendicular to the interface between the counter substrate and the first resin sealing portion and the interface between the electrode substrate and the first resin sealing portion, the stress is relaxed by the first resin sealing portion. For this reason, application of an excessive stress to the interface between the first resin sealing portion and the counter substrate as well as the interface between the electrode substrate and the first resin sealing portion is sufficiently suppressed and the peeling of the electrode substrate or the counter substrate from the first resin sealing portion is sufficiently suppressed. 
     In addition, when the photoelectric conversion element is placed under high temperature environment and the cell space is pressurized in the photoelectric conversion cell, a force pushing out the first resin sealing portion of the sealing portion to the outside acts on the first resin sealing portion, and a large shear stress is applied in a direction parallel to the interface between the electrode substrate and the first resin sealing portion. At this time, the second main body part of the second resin sealing portion is provided on a side of the counter substrate facing the direction opposite to the electrode substrate. For this reason, when it is assumed that the first resin sealing portion does not include the first protrusion part on a side of the first main body part facing the direction opposite to the electrode substrate, the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion is small. As a result, the difference between the shear stress applied to the interface between the electrode substrate and the first resin sealing portion, and the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion becomes considerably large, and the first resin sealing portion is easily peeled from the counter substrate. In contrast, when the first resin sealing portion has the first protrusion part on a side of the first main body part facing the direction opposite to the electrode substrate as in one or more embodiments of the present invention, the second main body part of the second resin sealing portion is adhered to the first protrusion part. For this reason, when a force pushing out the first resin sealing portion to the outside is applied and a stress to direct the first protrusion part to the outside is applied to the first protrusion part, the second main body part of the second resin sealing portion is simultaneously pulled outward by the first protrusion part, and a stress to direct the second main body part to the outside is applied. That is, the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion increases. For this reason, the difference between the shear stress applied to the interface between the electrode substrate and the first resin sealing portion and the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion can be sufficiently reduced, and the first resin sealing portion is less likely to be peeled from the counter substrate. 
     On the other hand, when the photoelectric conversion element is placed under a low temperature environment and the cell space is decompressed in the photoelectric conversion cell, a force to pull the first resin sealing portion of the sealing portion into the inside acts on the first resin sealing portion, and a large shear stress is applied in a direction parallel to the interface between the electrode substrate and the first resin sealing portion. At this time, the second main body part of the second resin sealing portion is provided on a side of the counter substrate facing the direction opposite to the electrode substrate. Therefore, when it is assumed that the first resin sealing portion does not include the first protrusion part on a side of the first main body part facing the direction opposite to the electrode substrate, the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion is small. As a result, the difference between the shear stress applied to the interface between the electrode substrate and the first resin sealing portion, and the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion becomes considerably large, and the first resin sealing portion is easily peeled from the counter substrate. In contrast, in a case where the first resin sealing portion has the first protrusion part on a side of the first main body part facing the direction opposite to the electrode substrate as in one or more embodiments of the present invention, the second main body part of the second resin sealing portion is adhered to the first protrusion part. For this reason, when a force to pull the first resin sealing portion into the inside is applied and a stress to direct the first protrusion part toward the inside is applied to the first protrusion part, the second main body part of the second resin sealing portion is simultaneously pushed toward the inside by the first protrusion part, and a stress to direct the second main body part toward the inside is applied to the second main body part. For this reason, the difference between the shear stress applied to the interface between the electrode substrate and the first resin sealing portion and the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion can be sufficiently reduced, and the first resin sealing portion is less likely to be peeled from the counter substrate. 
     Thus, according to the photoelectric conversion element of one or more embodiments of the present invention, the leakage of the electrolyte caused by the peeling of the first resin sealing portion from the electrode substrate or the counter substrate is sufficiently suppressed. Therefore, the photoelectric conversion element of one or more embodiments of the present invention can have excellent durability. 
     In one or more embodiments, in the above-mentioned photoelectric conversion element, it is preferable that the photoelectric conversion cell further comprise an oxide semiconductor layer on the electrode substrate or the counter substrate, and a dye supported on the oxide semiconductor layer, and that the oxygen permeability of the second resin sealing portion be smaller than the oxygen permeability of the first resin sealing portion. 
     In this case, the sealing portion includes the second resin sealing portion having an oxygen permeability smaller than that of the first resin sealing portion in addition to the first resin sealing portion. For this reason, compared to a case where the sealing portion does not include the second resin sealing portion, it is possible to sufficiently suppress the intrusion of oxygen into the electrolyte through the sealing portion, the deterioration due to oxygen of the dye supported on the oxide semiconductor layer is sufficiently suppressed, and the photoelectric conversion element can have more excellent durability. 
     In the above-mentioned photoelectric conversion element of one or more embodiments, A represented by the following formula (1) is preferably 1,200 to 60,000. 
         A=A 1/ A 2  (1)
 
     (A 1  represents the oxygen permeability of the first resin sealing portion and A 2  represents the oxygen permeability of the second resin sealing portion) 
     In this case, compared to a case where the value of A is out of the above range, the intrusion of oxygen into the electrolyte through the sealing portion is more sufficiently suppressed, the deterioration due to oxygen of the dye supported on the oxide semiconductor layer is more sufficiently suppressed, and the photoelectric conversion element can have more excellent durability. 
     In the above-mentioned photoelectric conversion element of one or more embodiments, the second resin sealing portion preferably includes a resin containing a vinyl alcohol unit. 
     In this case, since the oxygen permeability of the second resin sealing portion can be sufficiently reduced, the value of A represented by the above formula (1) can be easily adjusted. 
     In the above-mentioned photoelectric conversion element of one or more embodiments, ΔT represented by the following formula (2) is preferably 25° C. or higher. 
       Δ T=T 2− T 1  (2)
 
     (T 1  represents a melting point of the first resin sealing portion and T 2  represents a melting point of the second resin sealing portion.) 
     In this case, compared with a case where ΔT is less than 25° C., the peeling of the electrode substrate or the counter substrate from the first resin sealing portion is more sufficiently suppressed. 
     In the above-mentioned photoelectric conversion element of one or more embodiments, it is preferable that the first resin sealing portion further includes a second protrusion part on a side facing the direction opposite to the electrode substrate in the insertion part of the main body part, and that the second resin sealing portion include a second main body part provided on a side of the counter substrate facing the direction opposite to the electrode substrate, and a turning part which is connected to the second main body part and turns between the electrode substrate and the counter substrate, and the turning part be adhered to the second protrusion part. 
     In this case, the turning part of the second resin sealing portion turns between the electrode substrate and the counter substrate, and the turning part is adhered to the second protrusion part. Therefore, when the photoelectric conversion element is placed under a high temperature environment, and the cell space is pressurized in the photoelectric conversion cell, a force to push out the first resin sealing portion of the sealing portion to the outside is applied. At this time, when a stress to direct the second protrusion part to the outside is applied to the second protrusion part, a stress to direct the turning part adhered to the second protrusion part to the outside is also applied to the turning part. At this time, the stress applied to the turning part is transmitted to the second main body part of the second resin sealing portion, and a stress to direct the second main body part toward the outside is applied to the second main body part. For this reason, the difference between the shear stress applied to the interface between the electrode substrate and the first resin sealing portion and the shear stress applied to the interface between the counter substrate and the second main body part of the second resin sealing portion can be more sufficiently reduced, and the first resin sealing portion is less likely to be peeled from the counter substrate. As a result, the photoelectric conversion element can have more excellent durability. 
     In the above-mentioned photoelectric conversion element of one or more embodiments, R represented by the following formula (3) is preferably 3.0 or more. 
         R =( t 1+ t 2))/ t 1  (3)
 
     (In the above formula (3), t 1  represents a thickness (μm) of the first main body part and t 2  represents a thickness (μm) of the first protrusion part.) 
     In this case, compared to a case where R is less than 3.0, the photoelectric conversion element can have more excellent durability. 
     According to one or more embodiments of the present invention, a photoelectric conversion element having excellent durability can be provided. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cut surface end view illustrating a photoelectric conversion element of one or more embodiments of the present invention; 
         FIG. 2  is a cross-sectional view illustrating the counter substrate of  FIG. 1 ; 
         FIG. 3  is a partially enlarged view of  FIG. 1 ; 
         FIG. 4  is a cut surface end view illustrating a part of the photoelectric conversion element of one or more embodiments of the present invention; 
         FIG. 5  is a cut surface end view illustrating a part of the photoelectric conversion element of one or more embodiments of the present invention; and 
         FIG. 6  is a cut surface end view illustrating the photoelectric conversion element of one or more embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the photoelectric conversion element will be described in detail with reference to  FIGS. 1 to 3 .  FIG. 1  is a cut surface end view illustrating a photoelectric conversion element of one or more embodiments of the present invention;  FIG. 2  is a cross-sectional view illustrating a counter substrate of  FIG. 1 ; and  FIG. 3  is a partial enlarged view of  FIG. 1 . 
     As illustrated in  FIG. 1 , a photoelectric conversion element  100  has one photoelectric conversion cell  90 . The photoelectric conversion cell  90  includes an electrode substrate  10 ; a counter substrate  20  facing the electrode substrate  10 ; a ring-shaped sealing portion bonding the electrode substrate  10  and the counter substrate  20 ; an electrolyte  40  disposed inside the sealing portion  30 ; an oxide semiconductor layer  50  provided on a surface of the electrode substrate  10  facing the counter substrate  20 ; and a dye (not shown) supported on the oxide semiconductor layer  50 . 
     The electrode substrate  10  includes a transparent substrate  13 , a transparent conductive layer  14  provided on the transparent substrate  13  and a ring-shaped insulating part  15  on the transparent conductive layer  14  so as to surround the oxide semiconductor layer  50  and adhered to the sealing portion  30 . 
     As illustrated in  FIG. 2 , the counter substrate  20 , which includes a counter electrode, has a conductive substrate  21  which serves as a substrate and an electrode; and a catalyst layer  22  provided on the conductive substrate  21 . The catalyst layer  22  is provided on a side of the conductive substrate  21  facing the electrode substrate  10 . 
     The sealing portion  30  includes a ring-shaped first resin sealing portion  70  adhered to the electrode substrate  10 ; and a ring-shaped second resin sealing portion  80  provided so as to sandwich the counter substrate  20  together with the first resin sealing portion  70 . Herein, both the first resin sealing portion  70  and the second resin sealing portion  80  include a thermoplastic resin, and the second resin sealing portion  80  has a melting point higher than that of the first resin sealing portion  70 . 
     As illustrated in  FIG. 3 , the first resin sealing portion  70  includes a first main body part  71  adhered to the electrode substrate  10 ; and a first protrusion part  72  provided on a side of the first main body part  71  facing the direction opposite to the electrode substrate  10 . The first main body part  71  includes an insertion part  71   a  inserted between the electrode substrate  10  and the counter substrate  20 ; and a non-insertion part  71   b  which is not inserted between the electrode substrate  10  and the counter substrate  20 . The first main body part  72  is provided on a side of the non-insertion part  71   b  of the first main body part  71  facing the direction opposite to the electrode substrate  10 . 
     On the other hand, the second resin sealing portion  80  includes a second main body part  81  provided on a side of the counter substrate  20  facing the direction opposite to the electrode substrate  10 ; and an intermediate part  82  between the second main body part  81  and the first protrusion part  72 . 
     The second main body part  81  of the second resin sealing portion  80  is adhered to the first protrusion part  72  via the intermediate part  82 . The intermediate part  82  is adhered to the non-insertion part  71   b  of the first main body part  71 . 
     According to the photoelectric conversion element  100 , when the photoelectric conversion element  100  is placed under a high temperature environment, and in the photoelectric conversion cell  90  a space (cell space) between the counter substrate  20 , the electrode substrate  10  and the sealing portion  30  is pressurized, the counter substrate  20  and the electrode substrate  10  try to separate from each other. At this time, the sealing portion  30  includes the first resin sealing portion  70  having a melting point lower than that of the second resin sealing portion  80  and the first resin sealing portion  70  includes the insertion part  71   a  inserted between the electrode substrate  10  and the counter substrate  20 . For this reason, even if an excessive stress is about to be applied in a direction perpendicular to the interface between the counter substrate  20  and the first resin sealing portion  70  as well as the interface between the electrode substrate  10  and the first resin sealing portion  70 , the stress is relaxed by the first resin sealing portion  70 . Therefore, application of an excessive stress to the interface between the first resin sealing portion  70  and the counter substrate  20 , as well as the interface between the electrode substrate  10  and the first resin sealing portion  70  is sufficiently suppressed and peeling of the electrode substrate  10  or the counter substrate  20  from the first resin sealing portion  70  is sufficiently suppressed. 
     When the photoelectric conversion element  100  is placed under a high temperature environment, and the cell space is pressurized in the photoelectric conversion cell  90 , a force to push out the first resin sealing portion  70  of the sealing portion  30  acts on the first resin sealing portion  70  and a large shear stress is applied in a direction parallel to the interface between the electrode substrate  10  and the first sealing portion  70 . At this time, the second main body part  81  of the second resin sealing portion  80  is provided on a side of the counter substrate  20  facing the direction opposite to the electrode substrate  10 . For this reason, when it is assumed that the first resin sealing portion  70  does not include the first protrusion part  72  on a side of the first main body part  71  facing the direction opposite to the electrode substrate  10 , a shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  is small. As a result, the difference between the shear stress applied to the interface between the electrode substrate  10  and the first resin sealing portion  70  and the shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  becomes considerably large, and the first resin sealing portion  70  is easily peeled from the counter substrate  20 . In contrast, in a case where the first resin sealing portion  70  includes the first protrusion part  72  on a side of the first main body part  71  facing the direction opposite to the electrode substrate  10  as in the photoelectric conversion element  100 , the second main body part  81  of the second resin sealing portion  80  is adhered to the first protrusion part  72  through the intermediate part  82 . For this reason, when a force to push out the first resin sealing portion  70  to the outside is applied and a stress to direct the first protrusion part  72  toward the outside is applied to the first protrusion part  72 , the second main body part  81  is simultaneously pulled outward through the intermediate part  82  of the second resin sealing portion  80  by the first protrusion part  72 , and a stress to direct the second main body part  81  toward the outside is applied to the second main body part  81 . That is, a shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  is increased. For this reason, the difference between the shear stress applied to the interface between the electrode substrate  10  and the first resin sealing portion  70  and the shear stress applied to the interface between counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  can be sufficiently reduced and the first resin sealing portion  70  is less likely to be peeled from the counter substrate  20 . 
     On the other hand, when the photoelectric conversion element  100  is placed in a low temperature environment, and the cell space is decompressed in the photoelectric conversion cell  90 , a force to pull the first resin sealing portion  70  of the sealing portion  30  into the inside acts on the first resin sealing portion  70  and a large shear stress is applied in a direction parallel to the interface between the electrode substrate  10  and the first resin sealing portion  70 . At this time, the second main body part  81  of the second resin sealing portion  80  is provided on a side of the counter substrate  20  facing the direction opposite to the electrode substrate  10 . For this reason, when it is assumed that the first resin sealing portion  70  does not include the first protrusion part  72  on a side of the first main body part  71  facing the direction opposite to the electrode substrate  10 , a shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  is small. As a result, the difference between the shear stress applied to the interface between the electrode substrate  10  and the first resin sealing portion  70  and a shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  becomes considerably large, and the first resin sealing portion  70  is easily peeled from the counter substrate  20 . In contrast, in a case where the first resin sealing portion  70  includes the first protrusion part  72  on a side of the first main body part  71  facing the direction opposite to the electrode substrate  10  as in the photoelectric conversion element  100 , the second main body part  81  of the second resin sealing portion  80  is adhered to the first protrusion part  72  through the intermediate part  82 . For this reason, when a force to pull the first resin sealing portion  70  inside is applied and a stress to direct the first protrusion part  72  inward is applied to the first protrusion part  72 , the second main body part  81  is simultaneously pushed inward through the intermediate part  82  of the second resin sealing portion  80  by the first protrusion part  72  and a stress to direct the second main body part  81  inward is applied. Therefore, the difference between the shear stress applied to the interface between the electrode substrate  10  and the first resin sealing portion  70  and the shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  80  can be sufficiently reduced and the first resin sealing portion  70  is less likely to be peeled from the counter substrate  20 . 
     Thus, according to the photoelectric conversion element  100 , the leakage of the electrolyte  40  caused by the peeling of the first resin sealing portion  70  from the electrode substrate  10  or the counter substrate  20  is sufficiently suppressed. Therefore, the photoelectric conversion element  100  can have excellent durability. 
     Next, the electrode substrate  10 , the counter substrate  20 , and the sealing portion  30 , the electrolyte  40 , the oxide semiconductor layer  50 , and the dye will be described in detail. 
     &lt;&lt;Electrode Substrate&gt;&gt; 
     As described above, the electrode substrate  10  includes the transparent substrate  13 ; the transparent conductive layer  14  provided on the transparent substrate  13 ; and the ring-shaped insulating part  15  adhered to the sealing portion  30 . 
     &lt;Transparent Substrate&gt; 
     The material constituting the transparent substrate  13  may be any transparent material, for example, and examples of such a transparent material include glass such as borosilicate glass, soda lime glass, glass which is made of soda lime and whose iron component is less than that of ordinary soda lime glass, and quartz glass; polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), and polyethersulfone (PES). The thickness of the transparent substrate  13  is appropriately determined depending on the size of the photoelectric conversion element  100  and is not particularly limited, but it may be set to the range of from 50 to 40000 μm, for example. 
     &lt;Transparent Conductive Layer&gt; 
     Examples of the material constituting the transparent conductive layer  14  include a conductive metal oxide such as indium-doped-tin-oxide (ITO), tin oxide (SnO 2 ), and fluorine-doped-tin-oxide (FTO). The transparent conductive layer  14  may be constituted by a single layer or a laminate consisting of a plurality of layers which are constituted by different conductive metal oxides. It is preferable that the transparent conductive layer  14  be constituted by FTO since FTO exhibits high heat resistance and chemical resistance in a case in which the transparent conductive layer  14  is constituted by a single layer. The thickness of the transparent conductive layer  14  may be set to the range of from 0.01 to 2 μm, for example. 
     &lt;Insulating Part&gt; 
     The material constituting the insulating part  15  is not particularly limited as long as it is an insulating material, but, examples of the insulating material include, for example, an inorganic insulating material such as glass frit; a thermosetting resin such as a polyimide resin; and a thermoplastic resin. Among them, the inorganic insulating material such as glass frit or a thermosetting resin is preferably used. In this case, even if the sealing portion  30  has fluidity at a high temperature, the insulating part  15  is less likely to be fluidized even at a high temperature compared to the case where the insulating material is composed of a thermoplastic resin. Therefore, contact between the transparent conductive layer  14  of the electrode substrate  10  and the counter substrate  20  is sufficiently suppressed and short circuit between the transparent conductive layer  14  and the counter substrate  20  can be sufficiently suppressed. 
     Although the thickness of the insulating part  15  is not particularly limited, the thickness is typically 10 to 30 μm, and preferably 15 to 25 μm. 
     &lt;&lt;Counter Substrate&gt;&gt; 
     As described above, the counter substrate  20  includes the conductive substrate  21  which serves as a substrate and an electrode; and the catalyst layer  22  which is provided on a side of the conductive substrate  21  facing the electrode substrate  10  and promotes the catalyst reaction. 
     &lt;Conductive Substrate&gt; 
     The conductive substrate  21  is constituted by, for example, a corrosion-resistant metallic material such as titanium, nickel, platinum, molybdenum, tungsten, aluminum and stainless steel. Alternatively, the substrate and the electrode may be divided, and the conductive substrate  21  may be constituted by a stacked body in which a conductive layer made of a conductive oxide such as ITO, FTO or the like is formed as the electrode on the resin film, or may be a stacked body in which a conductive layer made of the conductive oxide such as ITO, FTO or the like is formed on glass. 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. However, the thickness may be set to 0.01 to 0.1 mm, for example. 
     &lt;Catalyst Layer&gt; 
     The catalyst layer  22  is made of a metal such as platinum, a carbon-based material, a conductive polymer or the like. 
     &lt;&lt;Sealing Portion&gt;&gt; 
     The sealing portion  30  includes the first resin sealing portion  70  and the second resin sealing portion  80 . 
     Examples of the thermoplastic resin contained in the first resin sealing portion  70  include a resin such as a modified polyolefin resin including an ionomer, an ethylene-vinyl acetate anhydride copolymer, an ethylene-methacrylic acid copolymer and an ethylene-vinyl alcohol copolymer; a vinyl alcohol polymer and the like. 
     In the first resin sealing portion  70 , the value of R represented by the following formula (3) is not particularly limited, but it is preferably 3.0 or more. 
         R =( t 1+ t 2))/ t 1  (3)
 
     (In the above formula (3), t 1  represents the thickness of the first main body part  71  and t 2  represents the thickness of the first protrusion part  72 ). 
     In this case, compared to a case where R is less than 3.0, the photoelectric conversion element  100  can have more excellent durability. 
     The value of R is more preferably 3.5 or more. However, the value of R is more preferably 21 or less. 
     The thickness of the first main body part  71  of the first resin sealing portion  70  is not particularly limited, but, typically 10 to 100 μm, and preferably 20 to 50 μm. 
     The thermoplastic resin contained in the second resin sealing portion  80  may be a resin which can give the second resin sealing portion  80  a melting point higher than that of the first resin sealing portion  70  and the same resin as the thermoplastic resin contained in the first resin sealing portion  70  can be used as the thermoplastic resin contained in the second resin sealing portion  80 . 
     ΔT, which is the difference between the melting point T 2  of the second resin sealing portion  80  and the melting point T 1  of the first resin sealing portion  70  and is represented by the following formula (2), is not particularly limited as long as it is more than 0° C. However, ΔT is preferably 25° C. or more. In this case, compared to a case where ΔT is less than 25° C., the peeling of the electrode substrate  10  or the counter substrate  20  from the first resin sealing portion  70  is more sufficiently suppressed. ΔT is preferably 35° C. or more. However, ΔT is preferably 60° C. or less. 
       Δ T=T 2− T 1  (2)
 
     The oxygen permeability of the second resin sealing portion  80  may be the same as or different from the oxygen permeability of the first resin sealing portion  70 . However, the oxygen permeability of the second resin sealing portion  80  is preferably smaller than the oxygen permeability of the first resin sealing portion  70 . In this case, the sealing portion  30  includes the second resin sealing portion  80  having an oxygen permeability smaller than that of the first resin sealing portion  70  in addition to the first resin sealing portion  70 . For this reason, compared to a case where the sealing portion  30  does not include the second resin sealing portion  80 , intrusion of oxygen into the electrolyte  40  through the sealing portion  30  is sufficiently suppressed, deterioration due to oxygen of the dye supported on the oxide semiconductor layer  50  is sufficiently suppressed, and the photoelectric conversion element  100  can have more excellent durability. 
     The value of A which is the ratio of the oxygen permeability A 1  of the first resin sealing portion  70  and the oxygen permeability A 2  of the second resin sealing portion  80  and is expressed by the following formula (1) is not particularly limited, but is preferably 1,200 to 60,000. In this case, compared to a case where the value of A is out of the above range, intrusion of oxygen into the electrolyte  40  through the sealing portion  30  is sufficiently suppressed, deterioration due to oxygen of the dye supported on the oxide semiconductor layer  50  is more sufficiently suppressed by oxygen, and the photoelectric conversion element  100  can have more excellent durability. The value of A is more preferably 2,400 to 8,000. The oxygen permeability of the second resin sealing portion  80  is not particularly limited, but is typically 0.21 to 2.5 (cc/20 μm 2 ·24 h/atm) and preferably from 0.5 to 2.0 (cc/20 μm 2 ·24 h/atm). 
         A=A 1/ A 2  (1)
 
     In addition, as the second resin sealing portion  80 , a resin containing a vinyl alcohol unit is preferable. In this case, since the oxygen permeability of the second resin sealing portion  80  can be sufficiently reduced, the value of A represented by the above formula (1) can be easily adjusted. Examples of the resin containing a vinyl alcohol unit include an ethylene-vinyl alcohol copolymer and a vinyl alcohol polymer. 
     The thickness of the second main body part  81  is not particularly limited, but, is typically 10 to 100 μm, and preferably 30 to 50 μm. 
     &lt;&lt;Electrolyte&gt;&gt; 
     The electrolyte  40  contains a redox pair and an organic solvent. It is possible to use acetonitrile, methoxy acetonitrile, 3-methoxy propionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, valeronitrile or pivalonitrile as the organic solvent. Examples of the redox pair include a redox couple such as a zinc complex, an iron complex, and a cobalt complex in addition to a redox pair containing a halogen atom such as iodide ion/polyiodide ion (for example, I − /I 3   − ), bromine ion/polybromide ion or the like. In addition, iodine ion/polyiodide ion can be formed by iodine (I 2 ) and a salt (an ionic liquid or a solid salt) containing iodide (I − ) as an anion. In a case of using the ionic liquid having iodide as an anion, only iodide may be added. In a case of using an organic solvent or an ionic liquid other than iodide as an anion, a salt containing iodide (I − ) as an anion such as LiI, tetrabutylammonium iodide or the like may be added. In addition, the electrolyte  40  may use an ionic liquid instead of the organic solvent. As the ionic liquid, for example, a known iodide salt such as a pyridinium salt, an imidazolium salt, or a triazolium salt is used. As such an iodide salt, for example, 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. 
     In addition, the electrolyte  40  may use a mixture of the ionic liquid and the organic solvent instead of the organic solvent. 
     In addition, it is possible to add an additive to the electrolyte  40 . Examples of the additive include benzimidazole such as 1-methylbenzimidazole (NMB) or 1-butylbenzimidazole (NBB), 4-t-butylpyridine and guanidium thiocyanate. Among them, benzimidazole is preferable as the additive. 
     Moreover, as the electrolyte  40 , a nanocomposite gel electrolyte which is a quasi-solid electrolyte obtained by kneading nanoparticles such as SiO 2 , TiO 2 , and carbon nanotubes with the electrolyte to form a gel-like form may be used, or an electrolyte gelled using an organic gelling agent such as polyvinylidene fluoride, a polyethylene oxide derivative or an amino acid derivative may also be used. 
     &lt;&lt;Oxide Semiconductor Layer&gt;&gt; 
     The oxide semiconductor layer  50  is composed of oxide semiconductor particles. The oxide semiconductor particles are composed of, for example, titanium oxide (TiO 2 ), zinc oxide (ZnO), tungsten oxide (WO 3 ), niobium oxide (Nb 2 O 5 ), strontium titanate (SrTiO 3 ), tin oxide (SnO 2 ), indium oxide (In 2 O 3 ), zirconium oxide (ZrO 2 ), thallium oxide (Ta 2 O 5 ), lanthanum oxide (La 2 O 3 ), yttrium oxide (Y 2 O 3 ), holmium oxide (Ho 2 O 3 ), bismuth oxide (Bi 2 O 3 ), cerium oxide (CeO 2 ), aluminum oxide (Al 2 O 3 ), or two or more kinds of these. The thickness of the oxide semiconductor layer  50  may be set to from 0.1 to 100 μm, for example. 
     The oxide semiconductor layer  50  is typically composed of an absorbing layer for absorbing light but may be composed of the absorbing layer and a reflective layer which returns the light transmitted through the absorbing layer to the absorbing layer by reflecting the light. 
     &lt;&lt;Dye&gt;&gt; 
     As the dye, for example, a photosensitizing dye such as a ruthenium complex having a ligand including a bipyridine structure, a terpyridine structure, an organic dye such as porphyrin, eosin, rhodanine or merocyanine; and an organic-inorganic composite dye such as a halogenated lead-based perovskite crystal may be exemplified. As the halogenated lead-based perovskite, for example, CH 3 NH 3 PbX 3  (X=Cl, Br, I) is used. Among the above-mentioned dyes, the ruthenium complex having a ligand including a bipyridine structure or a terpyridine structure is preferred. In this case, it is possible to more improve the photoelectric conversion characteristic of the photoelectric conversion element  100 . In addition, in a case where a photosensitizing dye is used as the dye, the photoelectric conversion element  100  is a dye-sensitized photoelectric conversion element. 
     Next, a method of manufacturing the photoelectric conversion element  100  will be described. 
     First, a conductive substrate obtained by forming the transparent conductive layer  14  on one transparent substrate  13  is prepared. 
     As a method of forming the transparent conductive layer  14 , a sputtering method, a vapor deposition method, a spray pyrolysis method (SPD) or a chemical vapor deposition (CVD) method can be used. 
     Further, a precursor of the oxide semiconductor layer  50  is formed on the transparent conductive layer  14 . 
     The precursor of the oxide semiconductor layer  50  can be formed by printing a paste for oxide semiconductor layer formation containing oxide semiconductor particles and then drying the paste. 
     The paste for oxide semiconductor layer formation includes a resin such as polyethylene glycol, and a solvent such as terpineol in addition to the oxide semiconductor particles. 
     As a method of printing the paste for oxide semiconductor layer formation, for example, a screen printing method, a doctor blade method, a bar coating method or the like can be used. 
     Then, the precursor of the oxide semiconductor layer  50  is fired to form the oxide semiconductor layer  50 . 
     The firing temperature varies depending on the kind of the oxide semiconductor particles, but is typically 350 to 600° C., and the firing time also varies depending on the kind of the oxide semiconductor particles, but is typically 1 to 5 hours. 
     Next, a precursor of the insulating part  15  is formed so as to surround the precursor of the oxide semiconductor layer  50 . 
     The precursor of the insulating part  15  can be formed, for example, by applying and drying a paste containing glass frit and drying the paste. 
     Then, the precursor of the insulating part  15  is fired to form the insulating part  15 . 
     Thus, the electrode substrate  10  on which the oxide semiconductor layer  50  and the insulating part  15  are formed is obtained. 
     Next, a ring-shaped first sealing portion forming body for forming the first resin sealing portion  70  is prepared. The first sealing resin sealing portion forming body can be obtained by preparing a first sealing resin film and forming one opening in the first sealing resin film, for example. 
     Then, the first sealing portion forming body is disposed along the insulating part  15  on the insulating part  15  so as to be adhered to the insulating part  15 . At this time, adhesion of the first sealing portion forming body to the insulating part  15  can be performed by heating and melting the first sealing portion forming body, for example. 
     Next, the dye is supported on the oxide semiconductor layer  50  of the electrode substrate  10 . To perform this, the dye may be adsorbed on the oxide semiconductor layer  50  by immersing the electrode substrate  10  in a solution containing the dye, then washing out the extra dye with the solvent component of the above solution after making the dye adsorb on the oxide semiconductor layer  50  and performing drying. However, it is also possible to support the dye on the oxide semiconductor layer  50  by coating a solution containing the dye on the oxide semiconductor layer  50  and then drying to adsorb the dye on the oxide semiconductor layer  50 . 
     Next, the electrolyte  40  is prepared. Then, the electrolyte  40  is disposed inside the ring-shaped sealing portion forming body fixed on the electrode substrate  10 . Thus, a structure A is obtained. 
     Next, the counter substrate  20  is prepared. 
     As described above, the counter substrate  20  can be obtained by forming the conductive catalyst layer  22  on the conductive substrate  21 . 
     Next, another first sealing portion forming body described above is prepared. 
     On the other hand, a second resin sealing portion forming body having a melting point higher than that of the above-described first sealing portion forming body is prepared. The second resin sealing portion forming body can be obtained by preparing a second sealing resin film and forming one opening in the second sealing resin film, for example. 
     The, the counter substrate  20  is arranged so as to block the opening of the first sealing portion forming body and then the first sealing portion forming body and the second sealing portion forming body are superimposed so as to sandwich the peripheral edge part of the counter substrate  20  by the first sealing portion forming body and the second sealing portion forming body. Then, the first sealing portion forming body and the second sealing portion forming body are adhered to the counter substrate  20 . In addition, adhesion of the first sealing portion forming body and the second sealing portion forming body to the counter substrate  20  can be performed by heating and melting the first sealing portion forming body and the second sealing portion forming body, for example. Thus, a structure B is obtained. 
     Next, the structure A and the structure B are superimposed, the first sealing portion forming body of the structure A as well as the first sealing portion forming body and the second sealing portion forming body of the structure B are heated and melted while being pressurized. Then, the softening of the first sealing portion forming body starts, the outer peripheral edge part of the first sealing portion forming body facing each other rises up in a direction away from the electrode substrate  10  while spreading outside and are adhered to the second sealing portion forming body. Thus, the sealing portion  30  is formed. 
     Thus, the photoelectric conversion element  100  is obtained. 
     The present invention is not limited to the above embodiments. For example, in the above embodiments, the photoelectric conversion element  100  includes one photoelectric conversion cell, but the photoelectric conversion element  100  may include a plurality of photoelectric conversion cells  90 . 
     In addition, in the above embodiments, the photoelectric conversion cell  90  includes the insulating part  15  between the sealing portion  30  and the electrode substrate  10 , but the insulating part  15  is not necessarily required, and can be omitted. 
     Furthermore, in the above embodiments, the second resin sealing portion  80  includes the second main body part  81  and the intermediate part  82 , but the second resin sealing portion  80  may be composed of only the second main body part  81 . That is, the second resin sealing portion  80  may not include the intermediate part  82 . In this case, the second main body part  81  is directly adhered to the first protrusion part  72 . 
     Further, in the above embodiments, the intermediate part  82  of the second resin sealing portion  80  is provided directly on the non-insertion part  71   b  of the first main body part  71  of the first resin sealing portion  70 , but as in a sealing portion  230  of a photoelectric conversion element  200  illustrated in  FIG. 4 , a first resin sealing portion  270  may have a second protrusion part  73  having a thickness smaller than that of the first protrusion part  72  on the non-insertion part  71   b  of the first main body part  71  and may have an intermediate part  82  on the second protrusion part  73 . In this case, the intermediate part  82  is adhered indirectly to the non-insertion part  71   b  of the first main body part  71  via the second protrusion part  73 . 
     Further, in the above embodiments, the second resin sealing portion  80  includes the second main body part  81  and the intermediate part  82 , and the first resin sealing portion  70  includes the first main body part  71  and the first protrusion part  72 , but as in a sealing portion  330  of a photoelectric conversion element  300  illustrated in  FIG. 5 , a second resin sealing portion  380  may further include a turning part  83  which is connected to the intermediate part  82  and turns between the electrode substrate  10  and the counter substrate  20  in addition to the second main body part  81  and the intermediate part  82 , and a first resin sealing portion  370  may further include a third protrusion part  74  on a side facing the direction opposite to the electrode substrate  10  in the insertion part  71   a  of the first main body part  71 . Herein, the turning part  83  is preferably adhered to the third protrusion part  74 . 
     In this case, the turning part  83  of the second resin sealing portion  380  turns between the electrode substrate  10  and the counter substrate  20 , and this turning part  83  is adhered to the third protrusion part  74 . For this reason, when the photoelectric conversion element  300  is placed under a high temperature environment and the cell space is pressurized in a photoelectric conversion cell  390 , a force to push out the first resin sealing portion  370  of the sealing portion  30  to the outside is applied. At this time, when a stress to direct the third protrusion part  74  to the outside is applied to the third protrusion part  74 , a stress to direct the turning part  83  adhered to the third protrusion part  74  to the outside is also applied to the turning part  83 . At this time, the stress applied to the turning part  83  is transmitted to the second main body part  81  of the second resin sealing portion  380 , and a stress to direct the second main body part  81  to the outside is applied to the second main body part  81 . For this reason, the difference between a shear stress applied to the interface between the electrode substrate  10  and the first resin sealing portion  370  and a shear stress applied to the interface between the counter substrate  20  and the second main body part  81  of the second resin sealing portion  380  can be sufficiently reduced, and the first resin sealing portion  370  is less likely to be peeled from the counter substrate  20 . As a result, the photoelectric conversion element  300  can have more excellent durability. 
     Furthermore, in the above embodiments, the conductive substrate  21  and the catalyst layer  22  constitutes the counter substrate  20 , but as in a photoelectric conversion cell  490  of a photoelectric conversion element  400  illustrated in  FIG. 6 , as the counter substrate, an insulating substrate  420  may be used instead of the counter substrate  20 . In this case, a structure  402  is disposed in a space between the insulating substrate  420 , the sealing portion  30  and the electrode substrate  10 . The structure  402  is provided on a surface of the electrode substrate  10  facing the insulating substrate  420 . The structure  402  includes, in order from the electrode substrate  10  side, the oxide semiconductor layer  50 , a porous insulating layer  403  and a counter electrode  401 . Further, in the space, the electrolyte  40  is arranged. The electrolyte  40  is impregnated into the oxide semiconductor layer  50  and the porous insulating layer  403 . Herein, as the insulating substrate  420 , for example, a glass substrate or a resin film can be used. As the counter electrode  401 , an electrode which is the same as the counter substrate  20  can be used. Alternatively, the counter electrode  401  may be composed of a porous single layer containing, for example, carbon. The porous insulating layer  403  is mainly used for preventing physical contact between the oxide semiconductor layer  50  and the insulating substrate  420  and impregnating the electrolyte  40  into the inside. As such the porous insulating layer  403 , for example, a fired body of an oxide can be used. In addition, in the photoelectric conversion element  400  illustrated in  FIG. 6 , only one structure  402  is provided in the space between the sealing portion  30 , the electrode substrate  10  and the insulating substrate  420 , but a plurality of the structures  402  may be provided. In addition, the porous insulating layer  403  is provided between the oxide semiconductor layer  50  and the counter electrode  401 , but the porous insulating layer may be provided between the electrode substrate  10  and the counter electrode  401  so as to surround the oxide semiconductor layer  50 . With this structure as well, it is possible to prevent physical contact between the oxide semiconductor layer  50  and the counter electrode  401 . 
     EXAMPLES 
     Hereinafter, the content of one or more embodiments of the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. 
     Example 1 
     First, a conductive substrate was obtained by forming a transparent conductive layer made of FTO and having a thickness of 0.7 μm on a transparent substrate having a thickness of 2.2 mm and composed of glass (trade name: TECa7, manufactured by Pilkington Group Limited) by a sputtering method. 
     Next, a precursor of an oxide semiconductor layer was formed on the transparent conductive layer. Specifically, the precursor of the oxide semiconductor layer was formed by printing a titanium oxide paste (trade name “PST-21NR”, manufactured by JGC Catalysts and Chemicals Ltd., the average particle diameter: 21 nm) with a thickness of 10 μm by screen printing first, and drying the paste. 
     Next, the precursor of the oxide semiconductor layer was fired at 500° C. for 30 minutes, and an oxide semiconductor layer was formed on the transparent conductive layer. 
     Next, a glass insulating part was formed by printing a paste of low melting point glass frit (trade name: “PLFOC-837B”, manufactured by Okuno Chemical Industries Co., Ltd.) such that the thickness after firing is 20 μm and the paste surround the oxide semiconductor layer, and then firing the paste at 500° C. for 30 minutes. Thus, an electrode substrate on which the oxide semiconductor layer and the glass insulating part were formed was obtained. 
     Next, a resin film made of low density polyethylene (product name “BYNEL 4164”, manufactured by DuPont, melting point: 127° C., oxygen permeability: 12,000 (cc/20 μm 2 ·24 h/atm)) was prepared, and a ring-shaped first sealing portion forming body was prepared by forming an opening in the resin film. 
     Then, the first sealing portion forming body was mounted on the glass insulating part, and then the first sealing portion forming body was welded to the glass insulating part by heat press. 
     Next, a dye was adsorbed on the oxide semiconductor layer by immersing the electrode substrate on which the first sealing portion forming body was formed in a dye solution for 16 hours. At this time, a 2907 dye solution of 0.2 mM was used as the dye solution. 
     Next, an electrolyte was disposed inside the first sealing portion forming body. As the electrolyte, an electrolyte obtained by dissolving iodine in a solvent comprising 3-methoxypropionitrile to have a concentration of 10 mM. Thus, the structure A was obtained. 
     Next, a counter substrate was prepared by forming a catalyst layer made of platinum and having a thickness of 10 nm on a titanium foil having a thickness of 40 μm by a sputtering method. At this time, in both surfaces of the titanium foil, masking was applied to a peripheral edge part to weld a sealing portion forming body such that catalyst was not formed. 
     Next, another ring-shaped first sealing portion forming body described above was prepared. On the other hand, a second sealing portion forming body for forming the second resin sealing portion was prepared. The ring-shaped second sealing portion forming body was prepared by preparing a resin film made of an ethylene vinyl alcohol copolymer (product name “EVELEF-E”, manufactured by KURARAY CO., LTD., melting point: 165° C., oxygen permeability: 1.5 (cc/20 μm 2 ·24 h)/atm)) and forming one opening in this resin film. 
     Then, after the counter substrate was arranged so as to block the opening of the first sealing portion forming body, the first sealing portion forming body and the second sealing portion forming body were superimposed so as to sandwich a peripheral part of the counter substrate by the first sealing portion forming body and the second sealing portion forming body. Then, the first sealing portion forming body and the second sealing portion forming body were adhered to the counter substrate by using a vacuum heat laminating method. Thus, a structure B was obtained. 
     Then, the structure A and the structure B were superimposed in a vacuum chamber having a degree of vacuum of 600 Pa, and the first sealing portion forming body of the structure A as well as the first sealing portion forming body and the second sealing portion forming body of the structure B were heated and melted while being pressurized by using a stepped hot mold obtained by providing a ring-shaped projection part on a main body part with the surface temperature of the projection part set to 200° C. At this time, the pressing was performed with press thrust set to about 1 kN. As a result, softening of the first sealing portion forming body started, the outer peripheral edge part of the first sealing portion forming body facing each other rose up in a direction away from the electrode substrate while spreading outside, and were adhered to the second sealing portion forming body. In this way, a sealing portion having a shape as illustrated in  FIG. 3  was formed. At this time, the thickness t 1  of the first main body part of the first resin sealing portion was 40 μm, the thickness t 2  of the first protrusion part was 80 μm, and R represented by the above-mentioned formula (3) was 3.0. 
     Thus, a photoelectric conversion element composed of one photoelectric conversion cell was obtained. 
     Comparative Example 1 
     A photoelectric conversion element was manufactured in the same manner as Example 1 except that a low-density polyethylene identical to that of the first sealing portion forming body was used in place of the ethylene vinyl alcohol copolymer. 
     Comparative Example 2 
     A photoelectric conversion element was manufactured in the same manner as Example 1 except that at the time of heating and melting the first sealing portion forming body of the structure A, as well as the first sealing portion forming body and the second sealing portion forming body of the structure B while pressurizing them, a sealing portion in which the first resin sealing portion did not include the first protrusion part in  FIG. 3  (that is, a sealing portion in which the value of R represented by the above-mentioned formula (3) was 1) was formed by changing the surface temperature of the projection part of the stepped hot mold from 200° C. to 180° C. and changing the press thrust from about 1 kN to about 0.5 kN. 
     &lt;Evaluation of Durability&gt; 
     For the photoelectric conversion elements of Example 1, Comparative Example 1 and Comparative Example 2 obtained as described above, heat cycle test was performed, and measurements of the IV curves was performed under an illuminance of 200 lux with a white LED used as a light source before and after the heat cycle test. The output retention rates were calculated on the basis of the output obtained from the IV curves and the following formula. The results are illustrated in Table 1. 
       Output retention rate (%)=output after heat cycle test/output before heat cycle test 
     In addition, 200 times of heat cycle tests were performed according to JIS C8917, with a heat cycle of lowering temperature to −40° C. and then raising temperature to 90° C. as one cycle. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                   
                 Presence or 
                   
                   
                   
                   
               
               
                   
                   
                 Absence of 
               
               
                   
                 Presence or 
                 First 
                 Thickness t1 
                 Thickness t2 
                   
                 Durability 
               
               
                   
                 Absence of 
                 Protrusion 
                 of First 
                 of First 
                   
                 Output 
               
               
                   
                 Second Resin 
                 Part in First 
                 Main Body 
                 Protrusion 
                   
                 Retention 
               
               
                   
                 Sealing 
                 Resin Sealing 
                 Part 
                 Part 
                 R 
                 Rate 
               
               
                   
                 Portion 
                 Portion 
                 (μm) 
                 (μm) 
                 (=(t1 + t2)/t1) 
                 (%) 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Example 1 
                 Present 
                 Present 
                 40 
                 80 
                 3 
                 95.2 
               
               
                 Comparative 
                 Absent 
                 — 
                 — 
                 — 
                 — 
                 92.4 
               
               
                 Example 1 
               
               
                 Comparative 
                 Present 
                 Absent 
                 40 
                  0 
                 1 
                 89.1 
               
               
                 Example 2 
               
               
                   
               
            
           
         
       
     
     From the results illustrated in Table 1, it was found that the output retention rate of the photoelectric conversion element of Example 1 was greater than the output retention rates of Comparative Examples 1 and 2. 
     From this, it was confirmed that the photoelectric conversion element of one or more embodiments of the present invention can have excellent durability. 
     EXPLANATIONS OF LETTERS OR NUMERALS 
     
         
         
           
               10  Electrode substrate 
               20  Counter substrate 
               30  Sealing portion 
               40  Electrolyte 
               50  Oxide semiconductor layer 
               70  First resin sealing portion 
               71  First main body part 
               71   a  Insertion part 
               71   b  Non-insertion part 
               72  First protrusion part 
               73  Second protrusion part 
               80  Second resin sealing portion 
               81  Second main body part 
               83  Turning part 
               90 ,  390 ,  490  Photoelectric conversion cell 
               100 ,  200 ,  300 ,  400  Photoelectric conversion element 
               420  Insulating substrate (counter substrate) 
           
         
       
    
     Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the present invention. Accordingly, the scope of the invention should be limited only by the attached claims.