JP2012099449A - Dye-sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell ensuring sufficient durability even under high-temperature environments.SOLUTION: The dye-sensitized solar cell 100 comprises a pair of electrodes 1 and 2 facing each other, a sealing part 4 connecting the pair of electrodes 1 and 2, and an electrolyte 3 filled into a cell space S formed by the pair of electrodes 1 and 2 and the sealing part 4. The sealing part 4 comprises a resin sealing portion 4A containing a resin, and the resin sealing portion 4A comprises a thickness decreasing portion 14b where the thickness decreases with increasing distance from the electrolyte 3 and touches the electrode 2 among the pair of electrodes 1 and 2 facing a tilted face of the thickness decreasing portion 14b along the tilted face.

Description

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

  As a photoelectric conversion element, a dye-sensitized solar cell is attracting attention because it is inexpensive and high photoelectric conversion efficiency can be obtained, and various developments have been made regarding the dye-sensitized solar cell.

  In general, a dye-sensitized solar cell connects a working electrode having a porous oxide semiconductor layer, a counter electrode, a photosensitizing dye supported on the porous oxide semiconductor layer of the working electrode, and the working electrode and the counter electrode. The sealing part and the electrolyte arrange | positioned in the space (henceforth "cell space") enclosed by a working electrode, a counter electrode, and a sealing part are provided.

  In such a dye-sensitized solar cell, the sealing part is often made of resin, and the thickness of the sealing part is generally constant (see, for example, Patent Documents 1 and 2 below).

JP 2008-153180 A JP 2006-4827 A

  However, the dye-sensitized solar cell described in Patent Document 1 described above still has room for improvement in terms of durability when used in a high humidity environment.

  That is, when the dye-sensitized solar cell described in Patent Document 1 is used in a high-humidity environment, if the thickness of the sealing portion is large, the cross-sectional area through which moisture passes through the sealing portion increases. It may easily enter the electrolyte through the sealing portion, and the photoelectric conversion efficiency may be reduced.

  On the other hand, in order to suppress the intrusion of moisture in the sealing portion, the thickness of the sealing portion may be reduced. However, in this case, since the thickness of the entire sealing portion is reduced, the adhesive force of the sealing portion to the working electrode and the counter electrode is weakened. For this reason, when the dye-sensitized solar cell is used in a high humidity environment, moisture easily enters from the interface between the working electrode or the counter electrode and the sealing portion.

  Therefore, there has been a demand for a dye-sensitized solar cell that can sufficiently suppress a decrease in photoelectric conversion efficiency and leakage of an electrolyte and can ensure sufficient durability.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dye-sensitized solar cell that can ensure sufficient durability even when used in a high humidity environment.

  In order to solve the above-mentioned problems, the present inventor has intensively studied paying attention to the thickness of the resin sealing portion containing resin. Here, in order to solve the above-mentioned problem, it is conceivable to adjust the thickness of the resin sealing portion to a value that is neither too thick nor too thin. However, sufficient durability could not be secured. Therefore, the present inventor thought that the above problem could be solved by changing the thickness depending on the position from the electrolyte in the resin sealing portion instead of making the thickness of the resin sealing portion constant. . As a result of further earnest research, the present inventor has found that the above-described problems can be effectively solved by the following invention.

  That is, the present invention includes a pair of electrodes facing each other, a sealing portion that connects the pair of electrodes, and an electrolyte that fills a cell space surrounded by the pair of electrodes and the sealing portion. The sealing portion has a resin sealing portion containing a resin, and the resin sealing portion is in contact with at least one electrode of the pair of electrodes and has a thickness that decreases as the distance from the electrolyte increases. It is a dye-sensitized solar cell which has a reduction | decrease part and contacts the electrode which opposes the said inclined surface among said pair of electrodes along the inclined surface of the said thickness decreasing part.

  According to this dye-sensitized solar cell, the resin sealing portion has a thickness decreasing portion that decreases in thickness as it is separated from the electrolyte, and is inclined among the pair of electrodes along the inclined surface of the thickness decreasing portion. It is in contact with the electrode facing the surface. For this reason, it is possible to sufficiently reduce the thickness on the side opposite to the electrolyte of the thickness reducing portion, and to further reduce the exposed area of the resin sealing portion with respect to the external atmosphere. Therefore, even when the dye-sensitized solar cell is used in a high humidity environment, the intrusion of moisture can be sufficiently suppressed. On the other hand, in the thickness decreasing portion, the thickness decreases as the distance from the electrolyte increases. That is, the thickness increases as the thickness approaches the electrolyte. For this reason, the adhesive force of the resin sealing part with respect to an electrode is fully strengthened by the thickness reduction part. Therefore, even when the dye-sensitized solar cell of the present invention is used in a high-humidity environment, it is possible to sufficiently suppress a decrease in the adhesive force of the resin sealing portion to the electrode, and the interface between the electrode and the resin sealing portion. Invasion of moisture from can be sufficiently suppressed. Therefore, according to the dye-sensitized solar cell of this invention, sufficient durability can be ensured even if it is used in a high humidity environment.

  In addition, the said thickness reduction | decrease part should just be in at least one part in a resin sealing part. For example, a thickness increasing portion that increases in thickness as it moves away from the electrolyte may be provided on the outermost side of the resin sealing portion. In other words, the thickness reducing portion may be located at any position of the resin sealing portion. In this case, even when the dye-sensitized solar cell is used in a high humidity environment, sufficient durability can be ensured. This is due to the following reason. That is, as long as the resin sealing portion has a thickness reduction portion, the thickness reduction portion makes the thickness sufficiently small on the side opposite to the electrolyte of the thickness reduction portion, and the resin sealing portion with respect to the external atmosphere The exposed area can be further reduced, and entry of moisture and air can be sufficiently suppressed. Therefore, even when the dye-sensitized solar cell is used in a high humidity environment, the intrusion of moisture and air can be sufficiently suppressed. On the other hand, in the thickness decreasing portion, the thickness decreases as the distance from the electrolyte increases. That is, the thickness increases as the thickness approaches the electrolyte. That is, there is a portion with a large thickness on the electrolyte side (side on which moisture and air are difficult to reach). In other words, the thickness can be secured at a position where the influence of moisture and air is small. For this reason, the adhesive force of the resin sealing part with respect to an electrode is fully strengthened by the thickness reduction part. Therefore, even when the dye-sensitized solar cell is used in a high-humidity environment, it is possible to sufficiently suppress a decrease in the adhesive strength of the resin sealing portion to the electrode.

  Further, in the dye-sensitized solar cell, the resin sealing portion further includes a thickness increasing portion that increases in thickness as the distance from the electrolyte increases, and the pair of the resin-encapsulated solar cells along the inclined surface of the thickness increasing portion. Of these electrodes, it is preferable to contact the electrode facing the inclined surface.

  In this case, the thickness becomes sufficiently small on the electrolyte side in the thickness increasing portion. That is, the passage cross-sectional area of the electrolyte can be narrowed on the electrolyte side in the increased thickness portion. For this reason, leakage of the electrolyte can be sufficiently suppressed.

  Here, the resin sealing portion further includes a thickness decreasing portion on the electrolyte side with respect to the thickness increasing portion, the thickness decreasing portion decreasing in thickness as the distance from the electrolyte increases, and the inclined surface of the thickness decreasing portion It is preferable to contact an electrode facing the inclined surface of the pair of electrodes.

  According to this dye-sensitized solar cell, the adhesive force of the resin sealing portion to the electrode is further strengthened by the thickness decreasing portion provided on the electrolyte side with respect to the thickness increasing portion.

  In the dye-sensitized solar cell, the resin sealing portion includes a plurality of the thickness reduction portions and the thickness increase portions, respectively, and the thickness reduction portions and the thickness increase portions approach the electrolyte. It is preferable that they are arranged alternately toward.

  In this case, since the sealing portion has a plurality of thickness decreasing portions and a plurality of thickness increasing portions, more sufficient durability can be ensured. In addition, when the dye-sensitized solar cell is used in a high-temperature environment and the internal pressure of the cell space increases, even if stress in the direction from the inner peripheral surface to the outer peripheral surface is applied to the resin sealing portion, that direction The movement of the resin sealing portion to the can be more sufficiently regulated.

  In the said dye-sensitized solar cell, it is preferable that the maximum thickness of the said resin sealing part is 10 micrometers or more.

  In this case, when the maximum thickness of the resin sealing portion is 10 μm or more, the thickness of the resin sealing portion is sufficiently secured, and the adhesive force of the resin sealing portion to the electrode is sufficiently secured. For this reason, leakage of the electrolyte and entry of moisture from the outside can be effectively suppressed.

  In the dye-sensitized solar cell, a groove extending so as to intersect in a direction away from the electrolyte is formed by a contact surface between the thickness decreasing portion and the electrode and a contact surface between the thickness increasing portion and the electrode. Preferably it is formed.

  In this dye-sensitized solar cell, a groove is formed by the contact surface between the reduced thickness portion and the electrode, and the contact surface between the increased thickness portion and the electrode. That is, the thickness decreasing portion and the thickness increasing portion are integrated into the groove. For this reason, even if the stress in the direction from the inner peripheral surface toward the outer peripheral surface is applied to the resin sealing portion, the dye-sensitized solar cell is used in a high temperature environment and the internal pressure of the cell space is increased. The movement of the resin sealing portion in that direction can be sufficiently restricted. Furthermore, by forming a groove in the electrode, it is possible to lengthen the passage path of the electrolyte that goes to the cell space through the interface between the electrode and the resin sealing portion, and the oxygen and moisture that penetrates from the outside and goes to the cell space. it can. In addition, when the electrolyte or moisture from the outside passes through the groove, a part of the electrolyte or the oxygen or moisture from the outside enters the groove and easily travels along the groove. As a result, entry of oxygen and moisture from the resin sealing portion into the cell space and leakage of the electrolyte from the resin sealing portion to the outside are sufficiently suppressed.

  In the dye-sensitized solar cell, it is preferable that at least one of the pair of electrodes has flexibility.

  In this case, even when the dye-sensitized solar cell is used in a high temperature environment and the internal pressure of the cell space increases, at least one of the pair of electrodes can be bent. For this reason, the stress applied to the interface between the resin sealing portion and the flexible electrode can be sufficiently relaxed.

  In the dye-sensitized solar cell, for example, one of the pair of electrodes includes a conductive substrate and a porous oxide semiconductor layer provided on the conductive substrate, The surface on the porous oxide semiconductor layer side may be a flat surface, and a contact surface between the thickness reducing portion and the other electrode of the pair of electrodes may be inclined with respect to the flat surface.

  The dye-sensitized solar cell further includes a covering portion that covers at least a boundary between the sealing portion and the pair of electrodes on a side opposite to the electrolyte with respect to the sealing portion, and the covering portion includes a resin. It is preferable.

  In this case, leakage of the electrolyte or penetration of oxygen and moisture from the outside into the electrolyte is suppressed not only by the sealing portion but also by the covering portion. In particular, leakage at the interface between the sealing portion and one electrode, the interface between the sealing portion and the other electrode, or intrusion of oxygen and moisture from the outside into the electrolyte is effectively suppressed by the covering portion.

  The present invention also includes a pair of electrodes facing each other, a sealing portion that connects the pair of electrodes, and an electrolyte that fills a cell space surrounded by the pair of electrodes and the sealing portion. The sealing portion has a resin sealing portion containing a resin, and the resin sealing portion is in contact with at least one electrode of the pair of electrodes and has a thickness that decreases as the distance from the electrolyte increases. It may be a dye-sensitized solar cell having a decreasing portion.

In the present invention, “flexible” for an electrode means that both edges (5 mm width each) of a long side of a sheet-like electrode of 50 mm × 200 mm are horizontally placed at a tension of 1 N under an environment of 20 ° C. The maximum deformation rate of the deflection of the electrode when a load of 20 g weight is applied to the center of the electrode is over 20%. Here, the maximum deformation rate is the following formula:
Maximum deformation rate (%) = 100 × (maximum displacement / sheet electrode thickness)
The value calculated based on Therefore, for example, when a sheet-like electrode having a thickness of 0.04 mm is bent by applying a load as described above, and the maximum displacement is 0.01 mm, the maximum deformation rate is 25%. It has “flexibility”.

  ADVANTAGE OF THE INVENTION According to this invention, even if it uses in a high humidity environment, the dye-sensitized solar cell which can ensure sufficient durability is provided.

It is sectional drawing which shows 1st Embodiment of the dye-sensitized solar cell of this invention. It is the elements on larger scale of FIG. It is the elements on larger scale which show the thickness increase part of FIG. FIG. 3 is a partial enlarged view showing a thickness reducing portion of FIG. 2. It is sectional drawing which shows the working electrode of FIG. It is sectional drawing which shows the counter electrode of FIG. It is a top view which shows the working electrode of FIG. It is sectional drawing which shows the inorganic sealing part formation process in the manufacturing process of the dye-sensitized solar cell of FIG. It is a top view which shows the counter electrode of FIG. It is sectional drawing which shows the resin sealing part formation process in the manufacturing process of the dye-sensitized solar cell of FIG. It is sectional drawing which shows the electrolyte arrangement | positioning process in the manufacturing process of the dye-sensitized solar cell of FIG. It is sectional drawing which shows the superposition | polymerization process in the manufacturing process of the dye-sensitized solar cell of FIG. It is sectional drawing which shows the sealing part formation process in the manufacturing process of the dye-sensitized solar cell of FIG. It is a partial expanded sectional view which shows 2nd Embodiment of the dye-sensitized solar cell of this invention. It is a partial expanded sectional view which shows 3rd Embodiment of the dye-sensitized solar cell of this invention. It is a partial expanded sectional view which shows 4th Embodiment of the dye-sensitized solar cell of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
First, a first embodiment of a dye-sensitized solar cell according to the present invention will be described with reference to FIGS. 1 is a sectional view showing a first embodiment of the dye-sensitized solar cell according to the present invention, FIG. 2 is a partially enlarged sectional view of FIG. 1, and FIG. 3 is a partially enlarged view showing a thickness increasing portion of FIG. 4 and 4 are partially enlarged views showing the thickness reducing portion of FIG.

  As shown in FIGS. 1 and 2, the dye-sensitized solar cell 100 includes a working electrode 1 and a counter electrode 2 disposed so as to face the working electrode 1. The working electrode 1 and the counter electrode 2 are connected by a sealing portion 4. The cell space S surrounded by the working electrode 1, the counter electrode 2, and the sealing portion 4 is filled with an electrolyte 3.

  The working electrode 1 includes a transparent substrate 6, a transparent conductive film 7 provided on the counter electrode 2 side of the transparent substrate 6, and a porous oxide semiconductor layer 8 provided on the transparent conductive film 7. Here, the sealing portion 4 is bonded to the surface 1 a of the transparent conductive film 7. The surface 1a of the transparent conductive film 7 may have irregularities (approximately 1 μm) of the size of the material constituting the transparent conductive film 7, but it does not have such irregularities. Also good. Hereinafter, the surface 1a that does not have irregularities of about the size of the crystal is described as a flat surface.

  A photosensitizing dye is supported on the porous oxide semiconductor layer 8 of the working electrode 1. In the dye-sensitized solar cell 100, the transparent substrate 6 and the transparent conductive film 7 constitute a conductive substrate.

  The counter electrode 2 includes a counter electrode substrate and a conductive catalyst film that is provided on the working electrode 1 side of the counter electrode substrate and promotes the reduction reaction on the surface of the counter electrode 2 and has flexibility.

  The sealing portion 4 includes a resin sealing portion 4A that is bonded to the counter electrode 2 and an inorganic sealing portion 4B that connects the resin sealing portion 4A and the working electrode 1. The resin sealing portion 4A is bonded to the counter electrode 2 at the second annular portion C2 of the counter electrode 2, and the inorganic sealing portion 4B is bonded to the first annular portion C1 of the working electrode 1. The inorganic sealing portion 4 </ b> B includes a current collecting wiring 11 fixed on the transparent conductive film 7 and a wiring protective layer 12 that covers and protects the current collecting wiring 11.

  The resin sealing portion 4A has a plurality of (for example, four) annular thickness increasing portions 14a that increase in thickness as they move away from the electrolyte 3, and a side opposite to the electrolyte 3 with respect to each of the plurality of thickness increasing portions 14a. And a plurality of (for example, four) annular thickness reducing portions 14b whose thickness decreases as the distance from the electrolyte 3 increases. That is, the resin sealing portion 4A has a thickness decreasing portion 14b on the outermost side, and has a thickness increasing portion 14a on the innermost side so as to come into contact with the electrolyte 3. In addition, the thickness increasing part 14a and the thickness decreasing part 14b are shown with a dashed-two dotted line in FIGS.

As shown in FIG. 3, the thickness of the thickness increasing portion 14a is H _A0 on the electrolyte 3 side, and H _A0 is the minimum thickness of the thickness increasing portion 14a. Then, the thickness of the thickness increasing portion 14 a increases as the distance from the electrolyte 3 increases, and becomes HA ₁ at the position farthest from the electrolyte 3. This _HA1 is the maximum thickness of the thickness increasing portion 14a.

On the other hand, the thickness of the reduced thickness portion 14b, as shown in FIG. 4, has a H _A1 with electrolyte 3 side, H _A1 is the maximum thickness of the reduced thickness portion 14b. The thickness of the thickness reducing portion 14b decreases as the distance from the electrolyte 3 increases, and is _HA0 at the position farthest from the electrolyte 3. This _HA0 is the minimum thickness of the thickness reducing portion 14b.

  Each of the plurality of annular thickness increasing portions 14 a and the plurality of annular thickness decreasing portions 14 b is formed continuously along the sealing portion 4, and is alternately arranged in a direction approaching the electrolyte 3. Yes. Here, among the resin sealing portions 4A, the innermost portion is the thickness increasing portion 14a, the outermost portion is the thickness decreasing portion 14b, and the innermost thickness increasing portion 14a is the electrolyte 3 In contact with.

  In the dye-sensitized solar cell 100, the thickness of the thickness increasing portion 14a is increased in proportion to the increase in the distance from the electrolyte 3. That is, the inclined surface 14c of the thickness increasing portion 14a is a flat surface. And 4A of resin sealing parts are contacting the thickness increasing part opposing contact surface 2a of the counter electrode 2 along the inclined surface 14c of the thickness increasing part 14a. For this reason, the thickness increasing portion facing contact surface 2a is also a flat surface. The thickness decreasing part 14b is decreasing in thickness so as to be proportional to the increase in the distance from the electrolyte 3. That is, the inclined surface 14d of the thickness reducing portion 14b is a flat surface. The resin sealing portion 4A is in contact with the thickness decreasing portion facing contact surface 2b of the counter electrode 2 along the inclined surface 14d of the thickness increasing portion 14a. For this reason, the thickness reducing portion facing contact surface 2b is also a flat surface.

  The thicknesses of the thickness increasing portion 14a and the thickness decreasing portion 14b are changed as described above, and the resin sealing portion 4A includes a plurality of thickness increasing portions 14a and a plurality of thickness decreasing portions 14b. For this reason, on the surface on the counter electrode 2 side of the resin sealing portion 4A, a plurality of annular protrusions are arranged in a direction away from the electrolyte 3, and the annular protrusions intersect in a direction away from the electrolyte 3. Will be formed. For this reason, the second annular portion C2 of the counter electrode 2 has a shape complementary to the plurality of protrusions. That is, in the second annular portion C2 of the counter electrode 2, a plurality of annular grooves 15 are arranged in a direction away from the electrolyte 3, and each annular groove 15 is formed to intersect in a direction away from the electrolyte 3. . In other words, each annular groove 15 extends along the annular thickness increasing portion 14a in the second annular portion C2 of the counter electrode 2.

  In addition, the thickness increase part 14a and the thickness decrease part 14b prescribe | regulate only the increase / decrease in those thickness. Accordingly, when there are a plurality of thickness increasing portions 14a and thickness decreasing portions 14b, the shapes of the plurality of thickness increasing portions 14a and the thickness decreasing portions 14b are not necessarily the same.

  Here, the annular groove 15 includes a thickness increasing portion facing contact surface 2a of the counter electrode 2 that contacts the thickness increasing portion 14a and a thickness decreasing portion of the counter electrode 2 that contacts the thickness decreasing portion 14b. It is formed by the opposing contact surface 2b. The thickness increasing portion facing contact surface 2a is inclined with respect to the flat surface 1a of the working electrode 1 so as to increase the thickness of the resin sealing portion 4A as the distance from the electrolyte 3 increases. The thickness reducing portion facing contact surface 2b is inclined with respect to the flat surface 1a of the working electrode 1 so as to reduce the thickness of the resin sealing portion 4A.

  According to the dye-sensitized solar cell 100 described above, the resin sealing portion 4A has the thickness reducing portion 14b, and the counter electrode 2 facing the inclined surface 14d along the inclined surface 14d of the thickness reducing portion 14b. In contact. For this reason, it is possible to make the thickness sufficiently small on the opposite side of the thickness reducing portion 14b from the electrolyte 3, and to further reduce the exposed area of the resin sealing portion 4A to the external atmosphere. Therefore, even if the dye-sensitized solar cell 100 is used in a high-humidity environment, the intrusion of moisture can be sufficiently suppressed. On the other hand, the thickness of the thickness reducing portion 14b decreases as the distance from the electrolyte 3 increases. In other words, the thickness of the thickness decreasing portion 14b increases as it approaches the electrolyte 3. For this reason, the adhesive force of the resin sealing portion 4A to the counter electrode 2 is sufficiently strengthened by the thickness reducing portion 14b. Therefore, even when the dye-sensitized solar cell 100 is used in a high humidity environment, it is possible to sufficiently suppress a decrease in the adhesive force of the resin sealing portion 4A to the counter electrode 2, and the counter electrode 2 and the resin sealing portion 4A Invasion of moisture from the interface can be sufficiently suppressed. Therefore, according to the dye-sensitized solar cell 100, sufficient durability can be ensured even when used in a high humidity environment.

  Further, in the dye-sensitized solar cell 100, the resin sealing portion 4A has the thickness increasing portion 14a that increases in thickness as the distance from the electrolyte 3 increases, and the inclined surface along the inclined surface 14c of the thickness increasing portion 14a. It contacts the counter electrode 2 facing 14c. Therefore, the thickness increasing portion 14a can be sufficiently reduced in thickness on the electrolyte 3 side to reduce the passage cross-sectional area of the electrolyte 3. As a result, leakage of the electrolyte 3 can be suppressed. Moreover, in the dye-sensitized solar cell 100, since the sealing part 4 is comprised by the resin sealing part 4A and the inorganic sealing part 4B which has higher sealing ability than the resin sealing part 4A, sealing is performed. Compared with the case where the inorganic sealing portion 4B is replaced with the resin sealing portion in the portion 4, the leakage of the electrolyte 3 can be more sufficiently suppressed. On the other hand, since the thickness increasing portion 14a increases with distance from the electrolyte 3, the adhesive strength of the resin sealing portion 4A to the counter electrode 2 is enhanced by the thickness increasing portion 14a. Accordingly, even when the dye-sensitized solar cell 100 is used in a high temperature environment and the pressure of the cell space S increases and an excessive stress is applied to the interface between the thickness increasing portion 14a and the counter electrode 2, the resin sealing from the counter electrode 2 is performed. Separation of the stop portion 4A can be sufficiently suppressed, and leakage of the electrolyte 3 can be sufficiently suppressed. Therefore, according to the dye-sensitized solar cell 100, sufficient durability can be ensured even when used in a high-temperature environment.

  In particular, in the dye-sensitized solar cell 100, the thickness increasing portion 14a is provided on the innermost side of the resin sealing portion 4A, and the thickness increasing portion 14a is in contact with the electrolyte 3. That is, when the dye-sensitized solar cell 100 is used in a high temperature environment and the internal pressure of the cell space S rises, the position where the greatest stress is applied and the resin-sealed portion is most likely to peel off is the position where the electrolyte 3 is in contact. The thickness increasing portion 14a is provided at this position. For this reason, sufficient adhesive force of 4 A of resin sealing parts with respect to the counter electrode 2 is ensured, and peeling of 4 A of resin sealing parts from the counter electrode 2 can be suppressed more effectively. Further, since the increased thickness portion 14a is in contact with the electrolyte 3, the exposed area of the resin sealing portion 4A with respect to the electrolyte 3 can be further reduced, and the leakage cross-sectional area of the electrolyte 3 can be reduced. Become. Therefore, leakage of the electrolyte 3 to the outside can be more sufficiently suppressed.

  In the dye-sensitized solar cell 100, in the resin sealing portion 4A, the plurality of annular thickness increasing portions 14a and the plurality of annular thickness decreasing portions 14b decrease in thickness to the outermost side of the resin sealing portion 4A. The portions 14 b are arranged and are alternately arranged in a direction approaching the electrolyte 3. For this reason, in the thickness reduction part 14b, thickness becomes small enough in the position most distant from the electrolyte 3. FIG. That is, the cross-sectional area of oxygen and moisture that enter from the outside can be reduced at the position farthest from the electrolyte 3 in the thickness reducing portion 14b. For this reason, compared with the case where the thickness reduction part 14b is not in the outermost part of the resin sealing part 4A, the penetration | invasion of oxygen from the exterior and a water | moisture content can be suppressed more fully. Further, in this dye-sensitized solar cell 100, an annular groove 15 is formed by the thickness increasing portion facing contact surface 2 a of the counter electrode 2 and the thickness decreasing portion facing contact surface 2 b of the counter electrode 2. That is, the thickness increasing portion 14 a and the thickness decreasing portion 14 b are integrated into the annular groove 15. For this reason, when the dye-sensitized solar cell 100 is used in a high-temperature environment and the internal pressure of the cell space S increases, the stress in the direction from the inner peripheral surface to the outer peripheral surface is applied to the resin sealing portion 4A. Even if added, the movement of the resin sealing portion 4A in the direction from the inner peripheral surface toward the outer peripheral surface can be sufficiently restricted. Further, in an environment where the temperature decreases as the temperature changes from evening to night, etc., the internal pressure of the cell space S decreases, so that the resin sealing portion 4A is exposed from the outer peripheral surface thereof. Stress in the direction toward the peripheral surface is applied. Also in this case, the movement of the resin sealing portion 4A in the direction from the outer peripheral surface toward the inner peripheral surface can be sufficiently restricted. In addition, the leakage cross-sectional area of the electrolyte 3 can be reduced at the position closest to the electrolyte 3, and leakage of the electrolyte 3 to the outside can be effectively suppressed.

  Further, by forming the annular groove 15 in the counter electrode 2, the electrolyte 3 that goes to the cell space S through the interface between the counter electrode 2 and the resin sealing portion 4A, and the interface between the counter electrode 2 and the resin sealing portion 4A from the outside The passage route of oxygen and moisture entering through can be made longer. In addition, when oxygen or moisture from the electrolyte 3 or the outside passes through the annular groove 15, part of oxygen or moisture from the electrolyte 3 or the outside enters the annular groove 15 and easily travels along the annular groove 15. As a result, intrusion of oxygen and moisture from the sealing portion 4 to the cell space S and leakage of the electrolyte S from the sealing portion 4 to the outside are sufficiently suppressed. In particular, moisture from the outside is easily captured by the annular groove 15, and the captured moisture easily travels along the annular groove 15, so that the amount of moisture toward the electrolyte 3 can be sufficiently reduced. In addition, in the dye-sensitized solar cell 100, what is formed on the surface of the counter electrode 2 is the annular groove 15 formed in a continuous manner. Therefore, when moisture is trapped in the annular groove 15, Will go along. For this reason, the trapped moisture can be confined in the annular groove 15.

  Furthermore, in this embodiment, the counter electrode 2 has flexibility. For this reason, even if the dye-sensitized solar cell 100 is used in a high-temperature environment and the internal pressure of the cell space S rises, the counter electrode 2 bends, so that the stress applied to the interface between the resin sealing portion 4A and the counter electrode 2 is increased. It can be relaxed sufficiently.

In the dye-sensitized solar cell 100, the maximum thickness of the resin sealing portion 4A, that is, H _A1 is not particularly limited, preferably at 10μm or more, more preferably 20μm or more, More preferably, it is 30 μm or more. When the maximum thickness of the resin sealing portion 4A is 10 μm or more, the thickness of the resin sealing portion 4A is sufficiently secured, and the adhesive force of the resin sealing portion 4A to the counter electrode 2 is sufficiently secured. For this reason, the leakage of the electrolyte 3 can be effectively suppressed, and the durability of the dye-sensitized solar cell 100 can be more sufficiently improved.

  However, the maximum thickness of the resin sealing portion 4A is preferably 1000 μm or less because the transmission cross-sectional area of the electrolyte 3 is reduced.

Further, the difference between the maximum value and the minimum value of the thickness of the resin sealing portion 4A, that is, (H _A1 −H _A0 ) may be any value as long as it is larger than 0 μm, but is preferably 1 to 95 μm, More preferably, it is 90 μm.

In this case, the durability of the dye-sensitized solar cell 100 can be further improved as compared with the case where (H _A1 -H _A0 ) is out of the above range.

  Next, the manufacturing method of the dye-sensitized solar cell 100 is demonstrated using FIGS.

[Preparation process]
First, the working electrode 1 and the counter electrode 2 are prepared.

(Working electrode)
The working electrode 1 can be obtained as follows (FIG. 5).

  First, a transparent conductive film 7 is formed on the transparent substrate 6 to form a laminate. As a method for forming the transparent conductive film 7, a sputtering method, a vapor deposition method, a spray pyrolysis (SPD) method, a CVD method, or the like is used. Of these, the spray pyrolysis method is preferable from the viewpoint of apparatus cost.

  The material which comprises the transparent substrate 6 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 , Polyethylene naphthalate (PEN), polycarbonate (PC), polyethersulfone (PES) and the like. The thickness of the transparent substrate 6 is appropriately determined according to the size of the dye-sensitized solar cell 100 and is not particularly limited, but may be in the range of 50 μm to 10000 μm, for example.

Examples of the material constituting the transparent conductive film 7 include tin-doped indium oxide (Indium-Tin-Oxide: ITO), tin oxide (SnO ₂ ), and fluorine-doped tin oxide (Fluorine-doped-Tin-Oxide: FTO). Examples include conductive metal oxides. The transparent conductive film 7 may be a single layer or a laminate of a plurality of layers made of different conductive metal oxides. When the transparent conductive film 7 is composed of a single layer, the transparent conductive film 7 is preferably composed of FTO because it has high heat resistance and chemical resistance. Moreover, it is preferable to use a laminated body composed of a plurality of layers as the transparent conductive film 7 because the characteristics of each layer can be reflected. Among these, it is preferable to use a laminate of a layer made of ITO and a layer made of FTO. In this case, the transparent conductive film 7 having high conductivity, heat resistance and chemical resistance can be realized. The thickness of the transparent conductive film 7 may be in the range of 0.01 μm to 2 μm, for example.

Next, a porous oxide semiconductor layer forming paste is printed on the transparent conductive film 7 of the laminate obtained as described above. The paste for forming a porous oxide semiconductor layer contains a resin such as polyethylene glycol and a solvent such as terpineol in addition to the oxide semiconductor particles. Examples of the oxide semiconductor particles include 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 ₃ 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 ), and the like. These can be used alone or in combination of two or more. As a printing method of the paste for forming the porous oxide semiconductor layer, for example, a screen printing method, a doctor blade method, a bar coating method, or the like can be used.

  Next, the porous oxide semiconductor layer forming paste is baked to form the porous oxide semiconductor layer 8 on the transparent conductive film 7. The firing temperature varies depending on the oxide semiconductor particles, but is usually 350 ° C. to 600 ° C., and the firing time also varies depending on the oxide semiconductor particles, but is usually 1 to 5 hours.

  The porous oxide semiconductor layer 8 is composed of a porous oxide semiconductor. A porous oxide semiconductor is comprised by the oxide semiconductor particle mentioned above, for example. The average particle diameter of these oxide semiconductor particles is 1-1000 nm, the surface area of the oxide semiconductor covered with the dye is increased, that is, the field for photoelectric conversion is increased, and more electrons are generated. Is preferable. Here, it is preferable that the porous oxide semiconductor layer 8 is configured by a stacked body in which oxide semiconductor particles having different particle size distributions are stacked. In this case, it becomes possible to cause reflection of light repeatedly in the laminated body, and light can be efficiently converted into electrons without escaping incident light to the outside of the laminated body. The thickness of the porous oxide semiconductor layer 8 may be, for example, 0.5 to 50 μm. In addition, the porous oxide semiconductor layer 8 can also be comprised with the laminated body of the several semiconductor layer which consists of a different material.

(Counter electrode)
On the other hand, the counter electrode 2 can be obtained as follows (FIG. 6).

  That is, first, a counter electrode substrate is prepared. Then, a catalyst film is formed on the counter electrode substrate. As a method for forming the catalyst film, a sputtering method, a vapor deposition method, or the like is used. Of these, sputtering is preferred from the viewpoint of film uniformity.

  As the counter electrode substrate, for example, a corrosion-resistant metal material such as titanium, nickel, platinum, molybdenum, or tungsten, a conductive oxide such as ITO or FTO, carbon, or a conductive polymer can be used.

  The catalyst film is made of platinum, a carbon-based material, a conductive polymer, or the like.

  The thickness of the counter electrode 2 is, for example, within a range of 0.005 mm to 0.1 mm, and the thickness at which the counter electrode 2 has flexibility may be appropriately determined.

  For example, when the counter electrode substrate is a metal material, the thickness of the counter electrode substrate that can impart flexibility to the counter electrode 2 is usually 500 μm or less, and preferably 200 μm or less. The lower limit may be a thickness that does not generate pinholes sufficiently, and this thickness varies depending on the method of manufacturing the foil and the type of metal. For example, when a rolled titanium foil is used as the counter electrode substrate, the thickness of the counter electrode substrate is usually 20 μm or more, but this is not limited to the case where a thin foil with sufficiently few pinholes can be obtained.

[Inorganic sealing part forming step]
Next, as shown in FIGS. 7 and 8, the inorganic sealing portion is formed in the first annular portion C1 of the working electrode 1 on the surface of the transparent conductive film 7 and surrounding the porous oxide semiconductor layer 8. 4B is formed. Specifically, the inorganic sealing part 4 </ b> B can be obtained by forming the current collecting wiring 11 in the first annular portion C <b> 1 of the transparent conductive film 7 and then covering the current collecting wiring 11 with the wiring protective layer 12. .

  Here, the current collector wiring 11 can be obtained by applying and baking a paste containing a metal material such as silver. The wiring protective layer 12 can be obtained, for example, by applying a paste containing an inorganic insulating material such as a lead-free transparent low melting point glass frit to the current collecting wiring 11 and baking it.

[Resin sealing part forming step]
On the other hand, as shown in FIGS. 9 and 10, the resin sealing portion 4 </ b> A is formed in the second annular portion C <b> 2 that is a portion on the surface of the counter electrode 2. Examples of the resin constituting the resin sealing portion 4A include thermoplastic resins such as ionomers, ethylene-vinyl acetic anhydride copolymers, ethylene-methacrylic acid copolymers, ethylene-vinyl alcohol copolymers, ultraviolet curable resins, And a vinyl alcohol polymer etc. are mentioned. When the resin sealing portion 4A is made of a thermoplastic resin, it can be obtained by preparing an annular sheet made of, for example, a thermoplastic resin, placing the sheet in the second annular portion C2, and heating and melting it. When the resin sealing portion 4A is an ultraviolet curable resin, the resin sealing portion 4A is obtained by applying an ultraviolet curable resin, which is a precursor of the ultraviolet curable resin, to the second annular portion C2 of the counter electrode 2. Can do.

[Dye support process]
Next, a photosensitizing dye is supported on the porous oxide semiconductor layer 8 of the working electrode 1. For this purpose, the working electrode 1 is immersed in a solution containing a photosensitizing dye, the dye is adsorbed on the porous oxide semiconductor layer 8, and then the excess dye is washed away with the solvent component of the solution. The photosensitizing dye may be adsorbed on the porous oxide semiconductor layer 8 by drying. However, the photosensitizing dye can be made porous by adsorbing the photosensitizing dye to the oxide semiconductor porous film by applying a solution containing the photosensitizing dye to the porous oxide semiconductor layer 8 and then drying it. It can be supported on the oxide semiconductor layer 8.

  Examples of the photosensitizing dye include a ruthenium complex having a ligand containing a bipyridine structure, a terpyridine structure, and the like, and organic dyes such as porphyrin, eosin, rhodamine, and merocyanine.

[Electrolyte layer placement process]
Next, as shown in FIG. 11, the electrolyte 3 is disposed on the working electrode 1 and inside the inorganic sealing portion 4B. The electrolyte 3 can be obtained by pouring or printing on the working electrode 1 and inside the inorganic sealing portion 4B.

  Here, when the electrolyte 3 is in a liquid state, the electrolyte 3 can be injected until it overflows beyond the inorganic sealing portion 4B and overflows to the outside of the inorganic sealing portion 4B. In this case, the electrolyte 3 can be sufficiently injected inside the inorganic sealing portion 4B. In addition, when the sealing portion 4 is formed by bonding the inorganic sealing portion 4B and the resin sealing portion 4A, air is sufficiently removed from the cell space S surrounded by the working electrode 1, the counter electrode 2, and the sealing portion 4. And the photoelectric conversion efficiency can be sufficiently improved.

The electrolyte 3 is usually composed of an electrolytic solution, and this electrolytic solution contains a redox couple such as I ⁻ / I ₃ ⁻ and an organic solvent. As the organic solvent, acetonitrile, methoxyacetonitrile, methoxypropionitrile, propionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, γ-butyrolactone, and the like can be used. Examples of the redox pair include I ⁻ / I ₃ ⁻ and bromine / bromide ion pairs. The dye-sensitized solar cell 100 is an electrolytic solution that includes a volatile solute such as I ⁻ / I ₃ ⁻ as an oxidation-reduction pair and an organic solvent such as acetonitrile, methoxyacetonitrile, and methoxypropionitrile that easily volatilizes at high temperatures. This is particularly effective when used as an electrolyte. In this case, the change in the internal pressure of the cell space S becomes particularly large due to the change in the ambient temperature around the dye-sensitized solar cell 100, and the interface between the sealing portion 4 and the counter electrode 2, and the sealing portion 4 and the working electrode 1 This is because the electrolyte 3 easily leaks from the interface. A gelling agent may be added to the volatile solvent. Moreover, the electrolyte 3 may be comprised with the ionic liquid electrolyte which consists of a mixture of an ionic liquid and a volatile component. This is also because the change in the internal pressure of the cell space S increases due to the change in the ambient temperature around the dye-sensitized solar cell 100. 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. As such a room temperature molten salt, for example, 1-ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide is preferably used. As the volatile component, the above and an organic solvent, 1-methyl-3-methyl imidazolium iodide, _LiI, and the like I 2, 4-t-butylpyridine. Further, as the electrolyte 3, a nanocomposite ionic gel electrolyte, which is a pseudo-solid electrolyte formed by kneading nanoparticles such as SiO ₂ , TiO ₂ , and carbon nanotubes in the ionic liquid electrolyte, may be used. An ionic liquid electrolyte gelled using an organic gelling agent such as vinylidene chloride, polyethylene oxide derivative, or amino acid derivative may be used.

[Polymerization process]
Next, as shown in FIG. 12, the working electrode 1 and the counter electrode 2 are opposed to each other, and the inorganic sealing portion 4B and the resin sealing portion 4A are overlapped.

[Sealing part forming step]
Next, the resin sealing portion 4 </ b> A is bonded to the inorganic sealing portion 4 </ b> B and the counter electrode 2.

  At this time, for example, when a thermoplastic resin is used as the resin constituting the resin sealing portion 4A, the resin sealing portion 4A is melted while being pressurized. Specifically, as shown in FIG. 13, the frame-shaped member 20 is used to heat and melt the resin sealing portion 4 </ b> A through the counter electrode 2 while applying pressure. Here, as the frame-shaped member 20, a member in which an annular groove 21 a having the same shape as the annular groove 15 to be formed in the counter electrode 2 is formed on the annular pressure surface 21 is used. Specifically, a structure in which a plurality of annular grooves 21 a are formed along the pressing surface 21 is used. Here, the material of the frame-shaped member 20 is preferably a material having good thermal conductivity, and examples of such a material include brass and copper. When the resin sealing portion 4A is heated and pressed using the frame-shaped member 20 having such a pressing surface 21, the counter electrode 2 has flexibility, so that the peripheral portion of the counter electrode 2 is easily deformed, and has a zigzag structure. It will have. That is, a plurality of annular grooves 15 are formed in the second annular portion C2 of the counter electrode 2 along a direction away from the electrolyte 3, and a plurality of annular grooves are also formed on the surface opposite to the second annular portion C2 of the counter electrode 2. 15 is formed. At this time, each annular groove 15 extends so as to intersect in a direction away from the electrolyte 3. A plurality of annular grooves 15 are formed in the second annular portion C2 of the counter electrode 2, and at the same time, a plurality of annular protrusions are formed on the counter electrode 2 side in the resin sealing portion 4A.

  In the zigzag structure, the shape of the pressing surface 21 is transferred via the counter electrode 2. For this reason, the shape of the pressure surface 21 is not necessarily formed by being transferred as it is, but is usually a deformed shape based on the shape of the pressure surface 21. For example, even if the annular groove 21a of the pressing surface 21 has a regular shape with a tip angle of 60 °, the groove shape with a tip angle of 60 ° is not directly transferred to the second annular portion C2 of the counter electrode 2. For example, the second annular portion C2 may have a groove shape with a slightly increased tip angle, for example, a groove with a tip angle of about 63 °. Furthermore, the tip angle varies depending on the location, and a 62 ° groove or a 70 ° groove may be formed in the second annular portion C2. The pressurizing surface 21 may be formed with a curved surface instead of a groove. In this case, a shape deformed based on the shape of the pressure surface 21 is formed in the second annular portion C2. Regardless of whether a groove or a curved surface is formed on the pressing surface 21, the thickness increasing portion 14a and the thickness decreasing portion 14b can be formed.

  Thus, the working electrode 1 and the counter electrode 2 are bonded together, and the sealing portion 4 is formed between the working electrode 1 and the counter electrode 2. At this time, the sealing part 4 is composed of a resin sealing part 4A and an inorganic sealing part 4B, and the resin sealing part 4A has a thickness decreasing part 14b on the outermost side, toward the direction approaching the electrolyte 3. The thickness decreasing portions 14b and the thickness increasing portions 14a are alternately arranged, and the thickness increasing portion 14a is provided on the innermost side of the resin sealing portion 4A. The bonding of the inorganic sealing portion 4B and the resin sealing portion 4A can be performed, for example, under atmospheric pressure.

  At this time, pressurization of the inorganic sealing portion 4B and the resin sealing portion 4A is normally performed at 1 to 50 MPa, preferably 2 to 30 MPa, more preferably 3 to 20 MPa.

  For example, when a thermoplastic resin is used as the resin constituting the resin sealing portion 4A, the temperature at which the resin sealing portion 4A is melted is equal to or higher than the melting point of the resin sealing portion 4A.

  However, the temperature at which the resin sealing portion 4A is melted is preferably (melting point of resin contained in the resin sealing portion 4A + 200 ° C.) or less. If the temperature exceeds (the melting point of the resin contained in the resin sealing portion 4A + 200 ° C.), the resin contained in the resin sealing portion 4A may be decomposed by heat.

  When the resin sealing portion 4A is an ultraviolet curable resin, the resin sealing portion 4A is bonded to the inorganic sealing portion 4B and the counter electrode 2 by irradiating the resin sealing portion 4A with ultraviolet rays while applying pressure. At this time, a frame-shaped member having the same shape as the frame-shaped member 20 is used, and the resin sealing portion 4A is irradiated with ultraviolet rays through the frame-shaped member while pressing the resin sealing portion 4A through the counter electrode 2. Here, as a material constituting the frame member, glass or the like that transmits ultraviolet rays is used. When the resin sealing portion 4A is pressed using this frame-shaped member, the counter electrode 2 has flexibility, so that the peripheral portion of the counter electrode 2 is easily deformed and has a zigzag structure. That is, a plurality of annular grooves 15 are formed in the second annular portion C2 of the counter electrode 2 along a direction away from the electrolyte 3, and a plurality of annular grooves are also formed on the surface opposite to the second annular portion C2 of the counter electrode 2. 15 is formed. At this time, each annular groove 15 extends so as to intersect in a direction away from the electrolyte 3. A plurality of annular grooves 15 are formed in the second annular portion C2 of the counter electrode 2, and at the same time, a plurality of annular protrusions are formed on the counter electrode 2 side in the resin sealing portion 4A.

  Thus, the dye-sensitized solar cell 100 is obtained, and the manufacture of the dye-sensitized solar cell 100 is completed.

<Second Embodiment>
Next, a second embodiment of the dye-sensitized solar cell according to the present invention will be described with reference to FIG. FIG. 14 is a partially enlarged cross-sectional view showing a second embodiment of the dye-sensitized solar cell according to the present invention. In FIG. 14, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 14, the dye-sensitized solar cell 200 of the present embodiment includes a boundary 13 between the sealing portion 4 and the working electrode 1, a boundary 14 between the sealing portion 4 and the counter electrode 2, and an outer periphery of the sealing portion 4. It differs from the dye-sensitized solar cell 100 of the first embodiment in that it further includes a covering portion 5 that covers the surface and the surface of the counter electrode 2 opposite to the sealing portion 4.

  In this case, leakage of the electrolyte 3 or intrusion of oxygen and moisture into the electrolyte 3 from the outside is suppressed not only by the sealing portion 4 but also by the covering portion 5. In particular, leakage at the boundary 14 between the sealing portion 4 and the counter electrode 2, and at the boundary 13 between the sealing portion 4 and the working electrode 1, or intrusion of oxygen or moisture from the outside into the electrolyte 3 is effectively performed by the covering portion 5. It is suppressed. Since the covering portion 5 also covers the surface of the counter electrode 2 opposite to the sealing portion 4, the electrolyte 3 that passes through the interface between the sealing portion 4 and the counter electrode 2 and the interface between the covering portion 5 and the counter electrode 2. It is also possible to suppress the leakage of moisture and oxygen from the outside through the interface between the sealing portion 4 and the counter electrode 2 and the interface between the covering portion 5 and the counter electrode 2 from the outside. In particular, since the annular groove is formed on the surface opposite to the sealing portion 4 of the counter electrode 2, compared to the case where the annular groove is not formed on the surface opposite to the sealing portion 4 of the counter electrode 2, The passing distance of the electrolyte 3, moisture, oxygen and the like becomes longer. For this reason, the interfacial leakage of the electrolyte 3 and the entry of moisture and oxygen from the outside can be more effectively suppressed.

  Here, the coating | coated part 5 contains resin. As the resin, acid-modified polyolefin, ultraviolet curable resin, polyvinyl alcohol, epoxy resin, or ethylene-vinyl alcohol copolymer can be used. In particular, when an acid-modified polyolefin or an ultraviolet curable resin is used as the resin, the adhesion between the covering portion 5 and the working electrode 1, the counter electrode 2, and the sealing portion 4 is strengthened. Invasion of oxygen and moisture from the outside to the electrolyte 3 can be more sufficiently suppressed.

  In addition, the coating | coated part 5 may contain inorganic materials, such as a metal and glass other than resin. In this case, the covering portion 5 may be one in which an inorganic material is dispersed in a resin, and may be configured by a laminate of a resin layer made of resin and an inorganic layer made of an inorganic material.

  The present invention is not limited to the first and second embodiments. For example, in the first and second embodiments, the sealing portion 4 is constituted by the resin sealing portion 4A and the inorganic sealing portion 4B, and the resin sealing portion 4A is bonded only to the counter electrode 2, but FIG. Like the dye-sensitized solar cell 300 shown in FIG. 4, the sealing portion 304 may be composed of only the resin sealing portion 4A, and the resin sealing portion 4A may be bonded to both the working electrode 1 and the counter electrode 2. That is, in the dye-sensitized solar cell 300, the sealing portion 304 may not have the inorganic sealing portion 4B. In this case, the thickness of the thickness increasing portion 14 a becomes the thickness of the sealing portion 304 as it is, and this thickness increases as the distance from the electrolyte 3 increases.

  In the first and second embodiments, the first annular portion C1 of the working electrode 1 is a flat surface, but the first annular portion C1 is not necessarily a flat surface. For example, one or a plurality of annular grooves 15 may be formed in the first annular portion C1 similarly to the second annular portion C2.

  Further, in the first and second embodiments, the thickness reducing portion 14b is provided on the outermost side of the resin sealing portion 4A, but the thickness reducing portion 14b is provided on the outermost side of the resin sealing portion 4A. It does not have to be. For example, the thickness increasing portion 14a may be provided on the outermost side of the resin sealing portion 4A. In other words, the thickness reduction part 14b may be in any position within the resin sealing part 4A. In this case, even when the dye-sensitized solar cell is used in a high humidity environment, sufficient durability can be ensured. This is due to the following reason. That is, as long as the resin sealing portion 4A has the thickness reduction portion 14b, the thickness reduction portion 14b can sufficiently reduce the thickness on the side opposite to the electrolyte 3 of the thickness reduction portion 14b. The exposed area of the resin sealing portion 4A can be further reduced, and entry of moisture and air can be sufficiently suppressed. Therefore, even when the dye-sensitized solar cell is used in a high humidity environment, the intrusion of moisture and air can be sufficiently suppressed. On the other hand, the thickness of the thickness reducing portion 14b decreases as the distance from the electrolyte 3 increases. In other words, the thickness of the thickness decreasing portion 14b increases as it approaches the electrolyte 3. That is, there is a portion with a large thickness on the electrolyte 3 side (side on which moisture and air are difficult to reach). In other words, the thickness can be secured at a position where the influence of moisture and air is small. For this reason, the adhesive force of the resin sealing portion 4A to the counter electrode 2 is sufficiently strengthened by the thickness reducing portion 14b. Therefore, even if the dye-sensitized solar cell is used in a high humidity environment, it is possible to sufficiently suppress a decrease in the adhesive force of the resin sealing portion 4A with respect to the counter electrode 2.

  In the first and second embodiments, the thickness increasing portion 14 a is in contact with the electrolyte 3, but the thickness increasing portion 14 a may not be in contact with the electrolyte 3. In other words, the sealing portion 4 includes a portion having a constant thickness and in contact with the electrolyte 3 relative to the thickness increasing portion 14a, and a thickness decreasing portion 14b that decreases in thickness as the distance from the electrolyte 3 decreases. You may have.

  In the first and second embodiments, the annular groove 15 is formed not only on the second annular portion C2 of the counter electrode 2 but also on the opposite side of the second annular portion C2 of the counter electrode 2. The annular groove 15 opposite to the two annular portions C2 is not necessarily required. For example, when the counter electrode 2 is not flexible, an annular groove 15 is formed in advance in the second annular portion C2 of the counter electrode 2 before pressurizing the resin sealing portion 4A. Pressurization may be performed using a frame-like member having a flat pressure surface. In this case, it is necessary to previously form the thickness increasing portion facing contact surface 2a of the counter electrode 2 and the thickness decreasing portion facing contact surface 2b of the counter electrode 2, which are components of the second annular portion C2 of the counter electrode 2. However, these can be formed by cutting the surface of the counter electrode 2 by sandblasting or water blasting.

  Further, in the first and second embodiments, the resin sealing portion 4A includes a plurality of thickness increasing portions 14a and a plurality of thickness decreasing portions 14b. The resin sealing portion 4A is illustrated in FIG. Like the dye-sensitized solar cell 400 shown, it is sufficient to have only one thickness decreasing portion 14b, and it is not always necessary to have the thickness increasing portion 14a.

  In the first and second embodiments, the thickness increasing portion 14a and the thickness increasing portion facing contact surface 2a of the counter electrode 2 and the thickness decreasing portion 14b and the thickness decreasing portion facing contact surface 2b of the counter electrode 2 are flat surfaces. However, the thickness increasing portion facing contact surface 2a and the thickness decreasing portion facing contact surface 2b are not necessarily flat surfaces, and the thickness of the thickness increasing portion 14a increases as the distance from the electrolyte 3 increases. Alternatively, it may be a curved surface as long as the thickness of the thickness reducing portion 14b can be reduced.

  Moreover, in the said 1st and 2nd embodiment, although the cyclic | annular thickness increase part 14a and the cyclic | annular thickness decrease part 14b are each formed continuously, you may form discontinuously.

  Furthermore, in the said 1st and 2nd embodiment, not only the counter electrode 2 but the working electrode 1 may have flexibility. Alternatively, the working electrode 1 may be flexible instead of the counter electrode 2.

  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, a 10 cm × 10 cm × 4 mm FTO substrate was prepared. Subsequently, titanium oxide paste (manufactured by Solaronix, Ti nanoixide) is formed on the FTO substrate by the doctor blade method.
T / sp) is applied to a thickness of 10 μm, and then placed in a hot air circulation type oven and baked at 500 ° C. for 3 hours to form a porous oxide semiconductor layer on the FTO substrate. A working electrode of 5 cm was obtained.

  Meanwhile, a counter electrode substrate made of titanium of 6 cm × 6 cm × 2 mm was prepared. Then, a platinum catalyst film having a thickness of 10 nm was formed on the counter electrode substrate by sputtering to obtain a counter electrode.

  Thus, a working electrode and a counter electrode were prepared.

  Next, a square annular resin sheet was prepared in which an opening of 5 cm × 5 cm × 100 μm was formed in the center of a 6 cm × 6 cm × 100 μm sheet made of ionomer Himiran (trade name, manufactured by Mitsui DuPont Polychemical Co., Ltd.). . And this resin sheet was arrange | positioned in the cyclic | annular site | part surrounding the porous oxide semiconductor layer of a working electrode. The resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the annular portion, and the first resin sealing portion was formed at the annular portion on the FTO substrate.

  Next, the working electrode was immersed in a dehydrated ethanol solution in which 0.2 mM of N719 dye, which is a photosensitizing dye, was dissolved for 24 hours to support the photosensitizing dye on the working electrode.

  On the other hand, the same resin sheet as described above was prepared, and this resin sheet was disposed at an annular portion on the platinum catalyst film of the counter electrode. Then, the resin sheet was heated and melted at 180 ° C. for 5 minutes to adhere to the annular portion, and the second resin sealing portion was formed at the annular portion on the platinum catalyst film of the counter electrode.

  Next, the working electrode provided with the first resin sealing portion is arranged so that the surface of the FTO substrate on the porous oxide semiconductor layer side is horizontal, and is made of methoxyacetonitrile inside the first resin sealing portion. A volatile electrolyte containing 0.1M lithium iodide, 0.05M iodine, and 0.5M 4-tert-butylpyridine was injected using a volatile solvent as the main solvent.

  Next, the counter electrode provided with the second resin sealing portion was opposed to the working electrode, and the first resin sealing portion and the second resin sealing portion were superposed under atmospheric pressure. Then, under atmospheric pressure, a brass frame-shaped member having the same size as the first resin sealing portion is heated, and this frame-shaped member is disposed on the side opposite to the second resin sealing portion of the counter electrode. Using a machine, the first resin sealing portion and the second resin sealing portion were heated and melted at 148 ° C. while pressurizing at 5 MPa to obtain a sealing portion consisting of one thickness reduction portion. At this time, a frame-shaped member having an annular pressure surface and the annular pressure surface being a notch surface was used. Specifically, when the frame-shaped member is placed on the flat surface and the pressure surface faces the flat surface, the outermost peripheral edge of the annular pressure surface is in contact with the flat surface, and the innermost peripheral edge of the annular pressure surface A frame-shaped member was used that was processed so that the height from the flat surface was 5 μm and the pressure surface was a flat surface. At this time, the thickness reducing portion was formed so that the minimum thickness was 10 μm and the difference between the maximum thickness and the minimum thickness was 5 μm. Thus, a dye-sensitized solar cell was obtained.

(Example 2)
A thickness increasing portion that increases in thickness with increasing distance from the electrolyte is further provided on the electrolyte side with respect to the thickness decreasing portion, and the minimum thickness of the thickness decreasing portion and the thickness increasing portion is 20 μm. Other than having formed the sealing part using Nukurel (Mitsui / DuPont Polychemical Co., Ltd.) which is an ethylene-methacrylic acid copolymer as the first and second resin sealing parts so that the difference between the two is 5 μm Prepared a dye-sensitized solar cell in the same manner as in Example 1. At this time, as the brass frame-like member, a member having an annular pressure surface, the annular pressure surface being constituted by one V-shaped groove having a depth of 5 μm and a width of 50 μm was used.

(Example 3)
It has two thickness decreasing portions and one thickness increasing portion, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed so that the minimum thickness was 20 μm and the difference between the maximum thickness and the minimum thickness was 5 μm. At this time, the brass frame-shaped member has an annular pressure surface, and the annular pressure surface has a depth of 5 μm and a width of 50 μm and a V-shaped annular groove inside thereof along the annular groove. What was comprised with one formed notch surface was used.

Example 4
Two thickness decreasing portions and two thickness increasing portions, the thickness decreasing portions and the thickness increasing portions are alternately formed toward the direction of approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed so that the minimum thickness was 20 μm and the difference between the maximum thickness and the minimum thickness was 5 μm. At this time, a brass frame-shaped member having an annular pressure surface, the annular pressure surface being composed of two V-shaped annular grooves having a depth of 5 μm and a width of 50 μm was used. .

(Example 5)
There are three thickness decreasing portions and three thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are Nucleel (Mitsui / DuPont), which is an ethylene-methacrylic acid copolymer, has a minimum thickness of 20 μm, a difference between the maximum thickness and the minimum thickness of 5 μm, and the first resin sealing portion and the second resin sealing portion. A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing part was formed using Polychemical Co., Ltd. At this time, a brass frame-shaped member having an annular pressure surface, the annular pressure surface being composed of three V-shaped annular grooves having a depth of 5 μm and a width of 50 μm was used. .

(Example 6)
It has five thickness decreasing portions and five thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte. A binel (DuPont) which is an ethylene-vinyl acetate anhydride copolymer so that the minimum thickness is 20 μm, the difference between the maximum thickness and the minimum thickness is 5 μm, and as the first resin sealing portion and the second resin sealing portion. A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed using the same method. At this time, a brass frame-shaped member having an annular pressure surface, the annular pressure surface being composed of five V-shaped annular grooves having a depth of 5 μm and a width of 50 μm was used. .

(Example 7)
It has six thickness decreasing portions and five thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are A binel (DuPont) which is an ethylene-vinyl acetate anhydride copolymer so that the minimum thickness is 20 μm, the difference between the maximum thickness and the minimum thickness is 5 μm, and as the first resin sealing portion and the second resin sealing portion. A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed using the same method. At this time, the brass frame-like member has an annular pressure surface, the annular pressure surface is 5 μm deep and 50 μm wide, and V-shaped annular grooves inside the annular groove along the annular groove. The one having a pressing surface having one notch surface formed in this manner was used.

(Example 8)
First, a working electrode and a counter electrode were prepared in the same manner as in Example 1.

  Next, the photosensitizing dye was supported on the working electrode by being immersed in a dehydrated ethanol solution in which 0.2 mM of N719 dye as a photosensitizing dye was dissolved for 24 hours.

  Next, 31x-101 (manufactured by Three Bond Co., Ltd.), which is a UV curable resin, was applied to an annular portion surrounding the porous oxide semiconductor layer of the working electrode and dried to form a first resin sealing portion.

  Next, 31x-101 which is UV curable resin was apply | coated and dried to the cyclic | annular site | part on the platinum thin film of a counter electrode, and the 2nd resin sealing part was formed.

  Next, the counter electrode provided with the second resin sealing portion is arranged so that the surface of the platinum thin film is horizontal, and inside the second resin sealing portion, a volatile solvent made of methoxyacetonitrile is used as a main solvent, and iodine A volatile electrolyte containing 0.1 M lithium iodide, 0.05 M iodine, and 0.5 M 4-tert-butylpyridine was injected.

  Next, the working electrode provided with the first resin sealing portion was opposed to the counter electrode, and the working electrode and the counter electrode were superposed under atmospheric pressure. Then, under atmospheric pressure, a brass frame-like member having the same size as the first resin sealing portion is arranged on the side opposite to the first resin sealing portion of the working electrode, and at 5 MPa using a press machine. The second resin sealing part was irradiated with ultraviolet rays while pressurizing the first resin sealing part and the second resin sealing part. In this way, the thickness decreasing portion is arranged on the outermost side of the resin sealing portion, and the sealing portion is formed by alternately arranging the eight thickness decreasing portions and the eight thickness increasing portions in the direction approaching the electrolyte. did. At this time, as the brass frame-like member, a member having an annular pressure surface, the annular pressure surface being composed of eight V-shaped grooves having a depth of 5 μm and a width of 50 μm was used. At this time, each of the thickness decreasing portion and the thickness increasing portion was formed so that the minimum thickness was 20 μm and the difference between the maximum thickness and the minimum thickness was 5 μm. Thus, a dye-sensitized solar cell was obtained.

Example 9
After forming the sealing part, a resin composition obtained by mixing glass in 31x-101, which is a UV curable resin, covers the boundary between the sealing part and the working electrode and the boundary between the sealing part and the counter electrode. A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the coating portion was formed by irradiating the resin composition with ultraviolet rays.

(Example 10)
After forming the sealing part, a resin composition obtained by mixing glass in 31x-101, which is a UV curable resin, covers the boundary between the sealing part and the working electrode and the boundary between the sealing part and the counter electrode. A dye-sensitized solar cell was produced in the same manner as in Example 4 except that the coating portion was formed by irradiating the resin composition with ultraviolet rays.

(Example 11)
After forming the sealing part, a dye-sensitized solar cell was produced in the same manner as in Example 1 except that the covering part was formed as follows.

  That is, first, a composite film was prepared by mixing glass in acid-modified polyolefin Nucrel (Mitsui / DuPont Polychemical Co., Ltd.). Next, the composite film is covered so as to cover the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode. The Teflon film was covered so that a composite film might be covered. Then, the composite film was heated and melted through the Teflon film and allowed to cool naturally at room temperature, and then the Teflon film was removed. Thus, a covering portion was formed.

(Example 12)
After forming the sealing part, a dye-sensitized solar cell was produced in the same manner as in Example 3 except that the covering part was formed as follows.

  That is, first, a composite film was prepared by mixing glass in an acid-modified polyolefin, Binnel (manufactured by DuPont). Next, the composite film is covered so as to cover the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode. The Teflon film was covered so that a composite film might be covered. Then, the composite film was heated and melted over the Teflon film and allowed to cool naturally at room temperature, and then the Teflon film was removed. Thus, a covering portion was formed.

(Example 13)
The minimum thickness of the thickness decreasing portion and the thickness increasing portion is 20 μm, the difference between the maximum thickness and the minimum thickness is 5 μm, and the sealing portion is made of high-milan as the first and second resin sealing portions. After the formation, a dye-sensitized solar cell was produced in the same manner as in Example 2 except that the covering portion was formed as follows.

  That is, first, a laminate of butyl rubber and an aluminum plate was prepared. Next, the laminated plate, with the butyl rubber layer facing the sealing portion side, the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode And a Teflon film so as to cover the laminate. Then, the laminate was heated and melted through the Teflon film and allowed to cool naturally at room temperature, and then the Teflon film was removed. Thus, a covering portion was formed.

(Example 14)
It has three thickness decreasing portions and two thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion Binel, an ethylene-vinyl acetate anhydride copolymer, having a minimum thickness of 40 μm, a difference between the maximum thickness and the minimum thickness of 5 μm, and as the first resin sealing portion and the second resin sealing portion A dye-sensitized solar cell was produced in the same manner as in Example 1 except that a sealing part was formed using and then a covering part was formed as follows.

  That is, first, a laminate of butyl rubber and an aluminum plate was prepared. Next, the laminated plate, with the butyl rubber layer facing the sealing portion side, the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode And a Teflon film so as to cover the laminate. Then, the laminate was heated and melted through the Teflon film and allowed to cool naturally at room temperature, and then the Teflon film was removed. Thus, a covering portion was formed.

(Example 15)
The minimum thickness of the thickness decreasing portion and the thickness increasing portion is 60 μm, the difference between the maximum thickness and the minimum thickness is 5 μm, and the first and second resin sealing portions are made of ethylene-vinyl acetate anhydride. A dye-sensitized solar cell was produced in the same manner as in Example 4 except that the sealing part was formed using the polymer binel and the covering part was formed as follows.

  That is, first, Maxive (Mitsubishi Gas Chemical Co., Ltd.), which is an epoxy resin composition, was prepared. Next, the epoxy resin composition is covered with the sealing portion so as to cover the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode. It was applied so as to surround it. Thereafter, the epoxy resin composition was cured by heating. Thus, a covering portion was formed.

(Example 16)
Dye sensitization in the same manner as in Example 15 except that the sealing portion was formed so that the minimum thickness of the reduced thickness portion and the increased thickness portion was 30 μm, and the difference between the maximum thickness and the minimum thickness was 90 μm. A solar cell was produced.

(Example 17)
Dye sensitization in the same manner as in Example 15 except that the sealing portion was formed so that the minimum thickness of the reduced thickness portion and the increased thickness portion was 30 μm, and the difference between the maximum thickness and the minimum thickness was 95 μm. A solar cell was produced.

(Example 18)
Dye sensitization in the same manner as in Example 15 except that the sealing portion was formed so that the minimum thickness of the reduced thickness portion and the increased thickness portion was 100 μm, and the difference between the maximum thickness and the minimum thickness was 50 μm. A solar cell was produced.

(Example 19)
There are three thickness decreasing portions and three thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are formed. Is the same as in Example 8 except that the sealing portion was formed so that the minimum thickness was 60 μm and the difference between the maximum thickness and the minimum thickness was 5 μm, and then the covering portion was formed as follows. Thus, a dye-sensitized solar cell was produced.

  That is, first, EP51Fl-2 (MASTER BOND), which is an epoxy resin composition, was prepared. Next, the epoxy resin composition is covered with the sealing portion so as to cover the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode. It was applied so as to surround it. Thereafter, the epoxy resin composition was cured by heating. Thus, a covering portion was formed.

(Example 20)
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed so that the difference between the minimum thickness and the maximum thickness in the sealing portion was 1 μm.

(Example 21)
A dye-sensitized solar cell was produced in the same manner as in Example 3 except that the sealing portion was formed so that the difference between the minimum thickness and the maximum thickness in the sealing portion was 1 μm.

(Example 22)
A dye-sensitized solar cell was produced in the same manner as in Example 9 except that the sealing portion was formed so that the difference between the minimum thickness and the maximum thickness in the sealing portion was 1 μm.

(Example 23)
It has one thickness decreasing portion and one thickness increasing portion, and the thickness decreasing portion and the thickness increasing portion are alternately formed in the direction approaching the electrolyte, and the minimum thickness and the maximum thickness in the sealing portion A dye-sensitized solar cell was produced in the same manner as in Example 11 except that the sealing portion was formed so that the difference between the two was 1 μm.

(Example 24)
There are three thickness decreasing portions and three thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are formed. In addition to forming the sealing portion so that the minimum thickness is 40 μm and the difference between the minimum thickness and the maximum thickness is 1 μm, and after forming the sealing portion, the covering portion is formed as follows. A dye-sensitized solar cell was produced in the same manner as in Example 1.

  That is, first, a laminate of butyl rubber and an aluminum plate was prepared. Next, the laminated plate, with the butyl rubber layer facing the sealing portion side, the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode And a Teflon film so as to cover the laminate. Then, the laminate was heated and melted through the Teflon film and allowed to cool naturally at room temperature, and then the Teflon film was removed. Thus, a covering portion was formed.

(Example 25)
There are three thickness decreasing portions and three thickness increasing portions, and the thickness decreasing portions and the thickness increasing portions are alternately formed in the direction approaching the electrolyte, and the thickness decreasing portion and the thickness increasing portion are formed. In addition to forming the sealing portion so that the minimum thickness is 40 μm and the difference between the minimum thickness and the maximum thickness is 1 μm, and after forming the sealing portion, the covering portion is formed as follows. A dye-sensitized solar cell was produced in the same manner as in Example 1.

  That is, first, EP008 (made by Yoneyama Chemical Co., Ltd.), which is an epoxy resin composition, was prepared. Next, the epoxy resin composition is covered with the sealing portion so as to cover the boundary between the sealing portion and the counter electrode, the boundary between the sealing portion and the working electrode, the outer peripheral surface of the counter electrode, and a part of the back surface of the counter electrode. It was applied so as to surround it. Thereafter, the epoxy resin composition was cured by heating. Thus, a covering portion was formed.

(Example 26)
A dye-sensitized solar cell was produced in the same manner as in Example 6 except that a 75 μm-thick counter electrode substrate in which an FTO film was formed on a PET film by sputtering was used.

(Example 27)
A dye-sensitized solar cell was produced in the same manner as in Example 6 except that a 75 μm-thick counter electrode substrate in which an FTO film was formed on a PEN film by sputtering was used.

(Example 28)
A thickness increasing portion that increases in thickness with increasing distance from the electrolyte is provided on the side opposite to the electrolyte with respect to the thickness decreasing portion, and the minimum thickness of the thickness decreasing portion and the thickness increasing portion is 20 μm, and the maximum thickness and the minimum As the first and second resin sealing portions, the sealing portion was formed using Nucrel (Mitsui / DuPont Polychemical Co., Ltd.), which is an ethylene-methacrylic acid copolymer, so that the difference from the thickness was 5 μm. Except for this, a dye-sensitized solar cell was produced in the same manner as in Example 1. At this time, as the brass frame-like member, a member having an annular pressure surface, the annular pressure surface being composed of one wedge-shaped protrusion having a height of 5 μm and a width of 50 μm was used.

(Example 29)
It has one thickness reduction part and two thickness increase parts, and a thickness reduction part and a thickness increase part are formed in the direction away from the electrolyte from the thickness increase part where the thickness increases as the distance from the electrolyte increases. In the same manner as in Example 28 except that the sealing portion was formed so that the minimum thickness of the thickness increasing portion and the thickness decreasing portion was 20 μm, and the difference between the maximum thickness and the minimum thickness was 5 μm. A solar cell was prepared. At this time, the brass frame-shaped member has an annular pressure surface, and the annular pressure surface extends along one V-shaped groove having a depth of 5 μm and a width of 50 μm and a V-shaped groove on the outside thereof. What was comprised with one notch surface formed in this way was used.

(Comparative Example 1)
A dye-sensitized solar cell was produced in the same manner as in Example 1 except that the sealing portion was formed so that the minimum thickness was 5 μm and the difference between the minimum thickness and the maximum thickness was 0 μm. At this time, as the frame member made of brass, the innermost peripheral edge and the outermost peripheral edge of the annular pressure surface are both flat when the frame member is placed on a flat surface and the pressure surface faces the flat surface side. A frame-shaped member processed so as to be in contact with the pressure surface and to be a flat surface was used.

(Comparative Example 2)
A dye-sensitized solar cell was produced in the same manner as in Example 8 except that the sealing portion was formed so that the minimum thickness was 20 μm and the difference between the minimum thickness and the maximum thickness was 0 μm. At this time, as the frame member made of glass, when the frame member is placed on a flat surface and the pressure surface faces the flat surface side, the innermost peripheral edge and the outermost peripheral edge of the annular pressure surface are both flat surfaces. A frame-shaped member processed so as to be in contact with the pressure surface and to be a flat surface was used.

(Comparative Example 3)
A dye-sensitized solar cell was produced in the same manner as in Example 2 except that the sealing portion was formed so that the minimum thickness was 40 μm and the difference between the minimum thickness and the maximum thickness was 0 μm. At this time, as the frame member made of brass, the innermost peripheral edge and the outermost peripheral edge of the annular pressure surface are both flat when the frame member is placed on a flat surface and the pressure surface faces the flat surface side. A frame-shaped member processed so as to be in contact with the pressure surface and to be a flat surface was used.

(Comparative Example 4)
A dye-sensitized solar cell was produced in the same manner as in Example 6 except that the sealing portion was formed so that the minimum thickness was 60 μm and the difference between the minimum thickness and the maximum thickness was 0 μm. At this time, as the frame member made of brass, the innermost peripheral edge and the outermost peripheral edge of the annular pressure surface are both flat when the frame member is placed on a flat surface and the pressure surface faces the flat surface side. A frame-shaped member processed so as to be in contact with the pressure surface and to be a flat surface was used.

[Durability evaluation of dye-sensitized solar cell under normal temperature, high humidity and atmospheric pressure environment: Evaluation 1]
About the dye-sensitized solar cell obtained in Examples 1-29 and Comparative Examples 1-4, the photoelectric conversion efficiency ((eta) ₀ ) was measured. Subsequently, the photoelectric conversion efficiency (η) of the dye-sensitized solar cell after being left at 1000 ° C. in a high humidity environment of 90% RH at 40 ° C. under atmospheric pressure was also measured. And the following formula:
Retention rate of photoelectric conversion efficiency (%) = η / η ₀ × 100
Based on the above, the retention rate of photoelectric conversion efficiency (photoelectric conversion retention rate) was calculated. The results are shown in Table 1.

[Durability evaluation of dye-sensitized solar cell under normal temperature, high humidity and low pressure environment: Evaluation 2]
About the dye-sensitized solar cells obtained in Examples 1 to 29 and Comparative Examples 1 to 4, the photoelectric conversion efficiency (η after leaving for 1000 h in a high humidity environment of 90% RH at 40 ° C. under a low pressure of 1500 hPa ) Was measured, and the retention rate of photoelectric conversion efficiency was calculated in the same manner as described above. The results are shown in Table 1.

[Durability evaluation of dye-sensitized solar cell under high temperature, high humidity and atmospheric pressure environment: Evaluation 3]
About the dye-sensitized solar cells obtained in Examples 1 to 29 and Comparative Examples 1 to 4, the photoelectric conversion efficiency (η) after being left for 1000 hours under a high humidity environment of 85% RH at 85 ° C. under atmospheric pressure The photoelectric conversion efficiency retention was calculated in the same manner as described above. The results are shown in Table 1.

  From the results shown in Table 1, the dye-sensitized solar cells of Examples 1 to 29 have a higher retention rate of photoelectric conversion efficiency in a high humidity environment than the dye-sensitized solar cells of Comparative Examples 1 to 4. I understood. In particular, it was found that the dye-sensitized solar cells of Examples 1 to 29 have a higher photoelectric conversion efficiency retention rate than the dye-sensitized solar cells of Comparative Examples 1 to 4 in a low-pressure environment. . In addition, it was found that the dye-sensitized solar cells of Examples 1 to 29 have a higher retention of photoelectric conversion efficiency in a high temperature and high humidity environment than the dye-sensitized solar cells of Comparative Examples 1 to 4. Furthermore, from the results of Example 2, Example 28, and Example 29, even when the resin sealing portion does not have the thickness reduction portion on the outermost side, the retention rate of the photoelectric conversion efficiency in the high humidity environment is I found it expensive.

  Therefore, according to the dye-sensitized solar cell of this invention, even if it used in a high-humidity environment, it was confirmed that sufficient durability can be ensured.

1 ... Working electrode (electrode)
2 ... Counter electrode (electrode)
DESCRIPTION OF SYMBOLS 3 ... Electrolyte 4 ... Sealing part 4A ... Resin sealing part 4B ... Inorganic sealing part 5 ... Covering part 13 ... Boundary between working electrode and sealing part 14 ... Boundary between counter electrode and sealing part 14a ... Thickness increase Part 14b ... Thickness reducing part 14c ... Inclined surface 14d ... Inclined surface 15 ... Annular groove 100, 200, 300, 400 ... Dye-sensitized solar cell S ... Cell space

Further, in the dye-sensitized solar cell, the resin sealing portion further includes a thickness increasing portion that increases in thickness as it is separated from the electrolyte , on a side opposite to the electrolyte with respect to the thickness decreasing portion. It is preferable that the electrode facing the inclined surface of the pair of electrodes is in contact with the inclined surface of the thickness increasing portion.

Here, the resin sealing portion further includes a thickness reduction portion on the opposite side to the electrolyte with respect to the thickness increase portion. It is preferable to contact the electrode facing the inclined surface of the pair of electrodes along the inclined surface.

According to this dye-sensitized solar cell, the adhesive force of the resin sealing portion to the electrode is further strengthened by the thickness decreasing portion provided on the side opposite to the electrolyte with respect to the thickness increasing portion.

Claims (9)

A pair of electrodes facing each other;
A sealing portion connecting the pair of electrodes;
An electrolyte that fills a cell space surrounded by the pair of electrodes and the sealing portion;
The sealing part has a resin sealing part containing resin,
The resin sealing portion has a thickness reducing portion that decreases in thickness as it moves away from the electrolyte, and is opposed to the inclined surface of the pair of electrodes along the inclined surface of the thickness reducing portion. A dye-sensitized solar cell, which is in contact with   The resin sealing portion further includes a thickness increasing portion on the electrolyte side with respect to the thickness decreasing portion, the thickness increasing portion increasing in thickness as the distance from the electrolyte increases, and along the inclined surface of the thickness increasing portion. The dye-sensitized solar cell according to claim 1, wherein the dye-sensitized solar cell is in contact with an electrode facing the inclined surface of the pair of electrodes.   The resin sealing portion further includes a thickness reduction portion on the electrolyte side with respect to the thickness increase portion. The thickness reduction portion decreases in thickness as the distance from the electrolyte increases, and along the inclined surface of the thickness reduction portion. The dye-sensitized solar cell according to claim 2, wherein the dye-sensitized solar cell is in contact with an electrode facing the inclined surface of the pair of electrodes. The resin sealing portion has a plurality of the thickness decreasing portion and the thickness increasing portion, respectively.
The dye-sensitized solar cell according to claim 2, wherein the thickness decreasing portion and the thickness increasing portion are alternately arranged in a direction approaching the electrolyte.   5. The dye-sensitized solar cell according to claim 1, wherein the resin sealing portion has a maximum thickness of 10 μm or more.   The groove | channel extended so that it may cross | intersect in the direction away from the said electrolyte is formed by the contact surface of the said thickness decreasing part and the said electrode, and the contact surface of the said thickness increasing part and the said electrode. The dye-sensitized solar cell as described in any one of -4.   The dye-sensitized solar cell according to any one of claims 1 to 6, wherein at least one of the pair of electrodes has flexibility. One electrode of the pair of electrodes has a conductive substrate and a porous oxide semiconductor layer provided on the conductive substrate,
The surface of the conductive substrate on the porous oxide semiconductor layer side is a flat surface;
The dye-sensitized solar cell according to any one of claims 1 to 7, wherein a contact surface between the thickness reducing portion and the other electrode of the pair of electrodes is inclined with respect to the flat surface. .   Any one of Claims 1-8 further provided with the coating | coated part which covers at least the boundary of the said sealing part and a pair of said electrode on the opposite side to the said electrolyte with respect to the said sealing part, and the said coating | coated part contains resin. A dye-sensitized solar cell according to claim 1.

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