JP2009238583A - Dye-sensitized solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell capable of obtaining high current collection efficiency despite a top-face contour shape of a power generating part. <P>SOLUTION: The dye-sensitized solar cell 10 includes: a transparent substrate 11; a collector electrode 12 formed at an underside of the transparent substrate 11; a flat-face electrode 13 formed so as to cover the underside of the transparent substrate 11 as well as the collector electrode 12; and a power generating part 14 with a top-face contour circular formed at an underside of the flat-face electrode 13. The collector electrode 12 comprises: a plurality of radial electrode lines 12a radially extended outward from a cell center; and a plurality of circular ring electrode lines 12b electrically connected with each radial electrode line 12a and arranged concentrically outward from the cell center. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  A dye-sensitized solar cell generally includes a transparent substrate, a planar electrode (negative electrode) attached to the transparent substrate, a power generation unit attached to the planar electrode, a counter substrate, and a counter substrate. The planar electrode (positive electrode), a sealing portion that seals between the one planar electrode and the other planar electrode so as to surround the power generation portion, and the power generation portion, the other planar electrode, and the sealing portion. It has a cell structure provided with a charge transport material filled in the formed space.

Both planar electrodes are made of tin-doped indium oxide (ITO) or the like, the power generation part is composed of a porous semiconductor film and a dye adsorbed on the surface, and the charge transport material is iodine redox couple (I ⁻ / I ₃ ⁻ ). It consists of an acetonitrile-based solvent containing

  According to this dye-sensitized solar cell, the current generated by the dye-sensitizing action when the power generation unit is irradiated with light such as sunlight through the transparent substrate and the flat electrode is changed to the terminal of one flat electrode and the other. It can take out from the terminal of this plane electrode.

  By the way, the specific resistance of tin-doped indium oxide (ITO) used for a planar electrode is higher than that of a metal such as gold or silver, and the value of the current extracted through the planar electrode is reduced by the influence of the specific resistance. Resulting in. In view of such circumstances, a cell structure in which a grid-like or comb-like collecting electrode is electrically connected to a planar electrode has been proposed (see Patent Document 1).

However, any of the grid-shaped or comb-shaped collecting electrodes has a quadrangular upper surface contour shape, and thus cannot be employed in a cell structure including a power generation unit having a top surface contour shape other than a quadrangle. For example, if the current collecting electrode is employed in a cell structure having a power generation part with a circular top surface profile, a region that does not reach the current collecting electrode occurs in the outer peripheral portion of the power generation part, making it difficult to collect current from the region. The current collection efficiency as a whole is reduced.
JP2003-203683A

  The present invention was created in view of the above circumstances, and an object of the present invention is to provide a dye-sensitized solar cell capable of obtaining high current collection efficiency regardless of the top surface contour shape of the power generation unit. .

  In order to achieve the present invention, a dye-sensitized solar cell of the present invention is a dye-sensitized solar cell having a cell structure including a power generation unit, a negative electrode, and a positive electrode, and includes a positive electrode and a negative electrode At least one of the side electrodes is connected to a plurality of radial electrode lines extending radially outward from the cell center and electrically connected to each radial electrode line, and is concentrically arranged outward from the cell center to generate power. The collector electrode comprised from the some annular electrode wire which has a shape similar to the upper surface outline shape of a part is provided.

  According to this dye-sensitized solar cell, the collector electrode is electrically connected to the plurality of radial electrode lines extending radially outward from the cell center, and to each radial electrode line, and from the cell center to the outside. Is formed of a plurality of annular electrode wires that are concentrically arranged and have a shape similar to the upper surface contour shape of the power generation unit, so that each radial electrode wire and each annular electrode wire of the collector electrode are connected to the power generation unit. The desired current collection can be efficiently performed through the radial electrode lines and the annular electrode lines so as to correspond to almost the entire region of the upper surface contour shape. In short, not only the power generation section having a quadrangular top surface shape but also a cell structure including a power generation section such as a circle, a triangle, or a hexagon other than the quadrangular top surface contour shape, the top surface contour shape of the power generation section Regardless, high current collection efficiency can be obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the dye-sensitized solar cell which can obtain high current collection efficiency irrespective of the upper surface outline shape of an electric power generation part can be provided.

  The above object and other objects, structural features, and operational effects of the present invention will become apparent from the following description and the accompanying drawings.

[First Embodiment]
1 and 2 show a first embodiment of the present invention. FIG. 1 is a top view of a cell of a dye-sensitized solar cell, and FIG. 2 is a longitudinal sectional view taken along line aa in FIG.

  The dye-sensitized solar cell 10 shown in FIGS. 1 and 2 includes a transparent substrate 11, a collecting electrode 12, a planar electrode 13, a power generation unit 14, a counter substrate 15, a planar electrode 16, and a sealing. It has a cell structure including a portion 17 and a charge transport material 18.

  The transparent substrate 11 is formed with a circular top shape from a transparent plastic such as polyethylene terephthalate or acrylic resin, transparent glass, or the like, and has a cutout portion 11a at a part of the outer periphery thereof. The transparent substrate 11 transmits light such as sunlight irradiated on the upper surface thereof downward.

  As shown by a broken line in FIG. 1, the current collecting electrode 12 is electrically connected to a plurality of (in the figure, 12) radial electrode lines 12a extending radially outward from the cell center and to each radial electrode line 12a. And a plurality of (six in the figure) annular electrode wires 12b that are concentrically arranged outward from the cell center and have a shape (circular) similar to the upper surface contour shape (circular) of the power generation unit 14. It is configured.

  Each radial electrode line 12a exists between the innermost annular electrode line 12b and the outermost annular electrode line 12b, and preferably does not protrude inward or outward from these annular electrode lines 12b. In the first embodiment, the outermost annular electrode wire 12b is used as a current extraction portion.

  The areas of the plurality of (60 in the figure) regions ER surrounded by two line segments of the two adjacent radial electrode lines 12a and two line segments of the two annular electrode lines 12b are substantially the same. ing. In order to easily make the areas of the respective regions ER substantially coincide with each other, the adjacent interval between the annular electrode lines 12b decreases from the cell center toward the outside. Moreover, since the upper surface contour shape of the power generation unit 14 is circular, the adjacent angles of the radial electrode lines 12a are all equal (30 degrees in the drawing) so that the area of each region ER can be easily adjusted. The reason why the areas of the respective regions ER are substantially matched will be described in detail later.

  Each radial electrode wire 12a and each annular electrode wire 12b of the collecting electrode 12 are formed of a metal or alloy having a specific resistance lower than that of the planar electrode 13, for example, a metal such as gold, silver, platinum, chromium, nickel, or an alloy thereof. Has been. As a method of forming the current collecting electrode 12, (1) a method of applying and baking a conductive paste containing metal powder or alloy powder on the lower surface of the transparent substrate 11 in a pattern shown by a broken line in FIG. A method of forming a metal or alloy with a pattern shown by a broken line in FIG. The radial sectional shape of each radial electrode line 12a and each annular electrode line 12b is basically arbitrary, but when the methods (1) and (2) are adopted, the longitudinal sectional shape is rectangular or semicircular. And approximate shapes. Moreover, it is preferable that the line width of each radial electrode line 12a and each annular electrode line 12b is as small as possible in order not to block the incidence of light such as sunlight.

  The planar electrode 13 is made of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or the like, and covers the lower surface of the transparent substrate 11 and the collecting electrode 12 by a thin film formation method such as sputtering or CVD. Is formed. The flat substrate 13 transmits light such as sunlight irradiated on the upper surface thereof downward. In the first embodiment, the planar electrode 13 and the collecting electrode 12 constitute a negative electrode.

The power generation unit 14 is composed of a porous semiconductor film and a dye adsorbed on the surface thereof, and is formed on the lower surface of the flat electrode 13 so that the upper surface contour shape is circular. The porous semiconductor film is an oxide or composite oxide having semiconductor characteristics, such as TiO ₂ , SnO ₂ , ZnO, Nb ₂ O ₅ , Nb ₂ O ₆ , ZrO ₂ , CeO ₂ , WO ₃ , SiO ₂ , Al _2. O ₃ , NiO, Ta ₂ O ₅ , CuAlO ₂ , SrCu ₂ O ₂ , SrTiO ₃ , CaTiO ₃ , KTaO _{3 and the} like. Since this porous semiconductor film has a large number of micropores substantially uniformly, the entire surface area including the inner surfaces of the micropores is extremely large. In addition, the dyes are ruthenium metal complex dyes, metal complex dyes such as osmium, iron, rhenium and copper other than ruthenium, organic substances such as methine dyes, mercurochrome dyes, xanthene dyes, porphyrin dyes, phthalocyanine dyes and coumarin dyes. Consists of pigments and the like.

  The counter substrate 15 is formed of a transparent plastic such as polyethylene terephthalate or acrylic resin, transparent glass, or the like, and the upper surface contour shape is a circle having the same size as the transparent substrate 11, and a cut portion is formed on a part of the outer periphery facing the cut portion 11a. 15a. Unlike the transparent substrate 11, the counter substrate 15 does not necessarily need to be transparent because it does not need to transmit light such as sunlight. Further, the counter substrate 15 can be formed of a metal plate such as titanium. In this case, the planar electrode 16 described later can be eliminated.

  The planar electrode 16 is made of a metal such as platinum or gold, carbon, a conductive polymer compound, or the like, and is formed by a thin film forming method such as a sputtering method or a CVD method, or a spin coating method, a dip coating method, a spray pyrolysis method, or the like. It is formed so as to cover the upper surface of the counter substrate 15 by a coating technique or the like. In the first embodiment, the flat electrode 16 constitutes a positive electrode, and the positive electrode is made of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or the like. The planar electrode 16 formed so as to cover the upper surface of 15 and the planar electrode 16 formed so as to cover the planar electrode may be used.

  The sealing portion 17 is made of a thermosetting plastic such as a silicone resin, an epoxy resin, or an acrylic resin, a photocurable plastic, or the like, and is formed in a circular frame shape so as to surround the outer periphery of the power generation portion 14. In the first embodiment, the sealing portion 17 seals the space between the planar electrode 13 and the planar electrode 16 and defines the distance between the lower surface of the planar electrode 13 and the upper surface of the planar electrode 16. Although serving as a spacer, a dedicated spacer may be used in combination with the sealing portion 17.

The charge transport material 18 is made of a liquid or gel containing a redox electrolyte, for example, an acetonitrile-based solvent containing iodine redox couple (I ⁻ / I ₃ ⁻ ), or a material added with a gelling agent. The charge transport material 18 is filled in a space defined by the power generation unit 14, the planar electrode 16, and the sealing unit 17.

  Although not shown, the negative electrode side terminal of the dye-sensitized solar cell 10 is connected to the outermost annular electrode wire 12b of the collector electrode 12 and the outer periphery of the planar electrode 13 so that the dye-sensitized solar cell 10 is electrically connected. It is provided on a part of the transparent substrate 11 exposed through the cut portion 15a of the counter substrate 15 when the sensitive solar cell 10 is viewed from the lower surface side. Further, the positive electrode side terminal of the dye-sensitized solar cell 10 is electrically connected to the outer peripheral portion of the planar electrode 16 when the dye-sensitized solar cell 10 is viewed from the upper surface side. It is provided on a part of the counter substrate 15 exposed through the cut portion 11a.

  In the dye-sensitized solar cell 10 described above, desired photoelectric conversion is performed in the following cycle. That is, when light such as sunlight is irradiated on the transparent substrate 11, the light reaches the pigment of the power generation unit 14 through the planar electrode 13 through each region ER of the collector electrode 12, and the pigment is excited by light energy. The electrons are emitted from the planar electrode 13 and the radial electrode lines 12a and the annular electrode lines 12b of the current collecting electrode 12 via the porous semiconductor film of the power generation unit 14, and the electrons are further It moves to the planar electrode 16 through an external circuit connected between the side terminal and the positive electrode side terminal. The dye oxidized by emitting electrons receives the electrons from the charge transport material 18 to be neutralized, and the charge transport material 18 oxidized by losing electrons receives the electrons transferred to the planar electrode 16 and is reduced.

  In short, the current generated by the dye sensitizing action when the power generation unit 14 is irradiated with light such as sunlight through the transparent substrate 11 and the planar electrode 13 can be taken out from the negative terminal and the positive terminal.

  In the dye-sensitized solar cell 10 described above, the current collecting electrode 12 is made of a material having a specific resistance lower than that of the flat electrode 13, so that the current collecting electrode 12 has a current collecting action (electron transfer) of the flat electrode 13. It also plays a role in increasing photoelectric conversion efficiency by compensating for the effects.

  As described above, the collecting electrode 12 is electrically connected to the plurality of radial electrode lines 12a extending radially outward from the cell center and to each radial electrode line 12a, and outward from the cell center. Since the upper surface contour shape of the power generation unit 14 is circular, the upper surface contour shape of the power generation unit 14 is circular. Even so, the radial electrode lines 12a and the annular electrode lines 12b of the collecting electrode 12 are extended so as to correspond to almost the entire region of the upper surface contour shape (circular shape) of the power generation unit 14, and the radial electrode lines 12a and The desired current collection can be performed with high efficiency through the annular electrode wire 12b.

  The areas of the plurality of regions ER surrounded by two line segments of the two adjacent radial electrode lines 12a of the current collecting electrode 12 and two line segments of the two annular electrode lines 12b adjacent to each other are substantially matched. Therefore, the current generated in each of the portions corresponding to each region ER of the power generation unit 14 can be collected by the four line segments that define the region ER under substantially the same resistance value. The current collection efficiency can be further increased by preventing a difference in current collection efficiency.

  Furthermore, since the interval between the annular electrode lines 12b of the current collecting electrode 12 is decreased from the center of the cell toward the outside, the areas of the respective regions ER can be easily matched.

  In the above description, the example in which the current collecting electrode 12 is arranged on the upper side of the power generation unit 14 so that the outermost annular electrode wire 12b of the current collecting electrode 12 is located inside the sealing portion 17 is exemplified. The current collecting electrode 12 may be arranged such that the outermost annular electrode wire 12 b is positioned above the sealing portion 17. In this case, a part of the surface of the outermost annular electrode line 12b of the collecting electrode 12 may be exposed.

  In the above description, the collector electrode 12 is disposed between the transparent substrate 11 and the planar electrode 13. However, the collector electrode 12 is disposed between the planar electrode 13 and the power generation unit 14. However, the same effect as described above can be obtained. In the case of this structure, since the charge transport material 18 is in contact with the current collecting electrode 12, when a material that can be deteriorated by the contact is used for the current collecting electrode 12, the material is resistant to the charge transport material 17, and The current collecting electrode 12 may be covered with a material that does not impede electrical performance, for example, an insulating material such as glass frit or an organic polymer compound. Further, in the case where a sufficient current collecting action can be expected with only the current collecting electrode 12, the planar electrode 13 can be eliminated. In this structure, a material that can be deteriorated by contact with the charge transporting material 18 is collected. When used for the current electrode 12, the current collection electrode 12 is preferably covered with the same material as described above that is resistant to the charge transport material 18 and does not impair the current collection performance.

  Further, in the above description, the current collector electrode 12 is used as the negative electrode. However, another current collector electrode having the same configuration as the current collector electrode 12 may be used as the positive electrode. Specifically, a current collecting electrode having the same configuration as the current collecting electrode 12 is used in place of the flat electrode 16 that is the positive electrode, or instead of the flat electrode 16 in the two-layered positive electrode described above. A current collecting electrode having the same configuration as the current collecting electrode 12 may be used. In this case, the technique described in the previous paragraph can be used to improve the resistance of the current collecting electrode to the charge transport material 18.

  Furthermore, in the above description, the radial electrode lines 12a and the annular electrode lines 12b of the current collecting electrode 12 are described as being made as small as possible so as not to block the incidence of light such as sunlight. If the line width of the part existing in the position away from the negative electrode side terminal of the line 12a and the annular electrode line 12b is made larger than the line width of the part existing in the position close to the negative electrode side terminal, the radial electrode line 12a and the annular electrode line 12b It is possible to reduce the electrical length of the portion located at a position away from the negative electrode side terminal and suppress the conduction loss due to the resistance value of the portion.

[Second Embodiment]
3 and 4 show a second embodiment of the present invention. FIG. 3 is a top view of a cell of a dye-sensitized solar cell, and FIG. 4 is a longitudinal sectional view taken along the line bb of FIG.

  The dye-sensitized solar cell 20 shown in FIGS. 3 and 4 includes a transparent substrate 21, a collecting electrode 22, a planar electrode 23, a power generation unit 24, a counter substrate 25, a planar electrode 26, The cell structure includes sealing portions 27-1 and 27-2 and a charge transport material 28.

  The transparent substrate 21 is formed of a transparent plastic such as polyethylene terephthalate or acrylic resin, transparent glass, or the like in a circular shape on the upper surface, and has a through hole 21a having a predetermined inner diameter at the center thereof. The transparent substrate 21 transmits light such as sunlight irradiated on the upper surface thereof downward.

  As shown by a broken line in FIG. 3, the collector electrode 22 is electrically connected to a plurality of (12 in the figure) radial electrode wires 22a extending radially outward from the cell center and to each radial electrode wire 22a. And a plurality of (six in the figure) annular electrode wires 22b that are concentrically arranged outward from the cell center and have a shape (circular) similar to the upper surface contour shape (circular) of the power generation unit 24. It is configured.

  Each radial electrode line 22a exists between the innermost annular electrode line 22b and the outermost annular electrode line 22b, and preferably does not protrude inward or outward from these annular electrode lines 22b. In the first embodiment, the innermost annular electrode wire 12b is used as a current extraction portion.

  The areas of the plurality of (60 in the figure) regions ER surrounded by two line segments of two adjacent radial electrode lines 22a and two line segments of two adjacent annular electrode lines 22b substantially coincide with each other. ing. In order to easily make the areas of the respective regions ER substantially coincide with each other, the adjacent interval between the annular electrode lines 22b decreases from the cell center toward the outside. Further, since the upper surface contour shape of the power generation unit 24 is circular, the adjacent angles of the radial electrode lines 22a are all equal (30 degrees in the figure) so that the area of each region ER can be easily adjusted. The reason why the areas of the respective regions ER are substantially matched will be described in detail later.

  Each radial electrode line 22a and each annular electrode line 22b of the collecting electrode 22 are formed of a metal or alloy having a specific resistance lower than that of the planar electrode 23, for example, a metal such as gold, silver, platinum, chromium, nickel, or an alloy thereof. Has been. As a method of forming the current collecting electrode 22, (1) a method of applying and baking a conductive paste containing metal powder or alloy powder on the lower surface of the transparent substrate 21 in a pattern indicated by a broken line in FIG. A method of forming a metal or alloy with a pattern indicated by a broken line in FIG. 3 on the lower surface of the transparent substrate 11 by a thin film forming method such as CVD or CVD can be preferably employed. The radial sectional shape of each radial electrode line 22a and each annular electrode line 22b is basically arbitrary, but when the methods (1) and (2) are adopted, the longitudinal sectional shape is rectangular or semicircular. And approximate shapes. Moreover, it is preferable that the line width of each radial electrode line 22a and each annular electrode line 22b is as small as possible in order not to block the incidence of light such as sunlight.

  The planar electrode 23 is made of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or the like, and covers the lower surface of the transparent substrate 21 and the current collecting electrode 22 by a thin film formation method such as sputtering or CVD. A through hole 23a having the same inner diameter as the through hole 21a is formed at the center thereof. The planar substrate 23 transmits light such as sunlight irradiated on the upper surface thereof downward. In the second embodiment, the planar electrode 23 and the collecting electrode 22 constitute a negative electrode.

The power generation unit 24 includes a porous semiconductor film and a dye adsorbed on the surface thereof, and is formed on the lower surface of the planar electrode 13 so that the upper surface contour shape is circular and has a circular hole in the center. The porous semiconductor film is an oxide or composite oxide having semiconductor characteristics, such as TiO ₂ , SnO ₂ , ZnO, Nb ₂ O ₅ , Nb ₂ O ₆ , ZrO ₂ , CeO ₂ , WO ₃ , SiO ₂ , Al _2. O ₃ , NiO, Ta ₂ O ₅ , CuAlO ₂ , SrCu ₂ O ₂ , SrTiO ₃ , CaTiO ₃ , KTaO _{3 and the} like. Since this porous semiconductor film has a large number of micropores substantially uniformly, the entire surface area including the inner surfaces of the micropores is extremely large. In addition, the dyes are ruthenium metal complex dyes, metal complex dyes such as osmium, iron, rhenium and copper other than ruthenium, organic substances such as methine dyes, mercurochrome dyes, xanthene dyes, porphyrin dyes, phthalocyanine dyes and coumarin dyes. Consists of pigments and the like.

  The counter substrate 25 is formed of a transparent plastic such as polyethylene terephthalate or acrylic resin, transparent glass, or the like, and the upper surface contour shape is a circle having the same size as that of the transparent substrate 21, and a through hole having the same inner diameter as the through hole 21a is formed at the center thereof. 25a. Unlike the transparent substrate 21, the counter substrate 25 does not necessarily need to be transparent because it does not need to transmit light such as sunlight. Further, the counter substrate 25 can be formed of a metal plate such as titanium. In this case, the planar electrode 26 described later can be eliminated.

  The planar electrode 26 is made of a metal such as platinum or gold, carbon, a conductive polymer compound, or the like, and includes a thin film forming method such as a sputtering method or a CVD method, a spin coating method, a dip coating method, a spray pyrolysis method, or the like. It is formed so as to cover the upper surface of the counter substrate 25 by a coating technique or the like, and has a through hole 26a having the same inner diameter as the through hole 21a at the center. In the second embodiment, the planar electrode 26 constitutes a positive electrode, and the positive electrode is made of tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), or the like. Alternatively, a two-layer structure of a planar electrode formed so as to cover the upper surface of 25 and the planar electrode 26 formed so as to cover the planar electrode may be employed.

  The sealing portions 27-1 and 27-2 are made of a thermosetting plastic such as a silicone resin, an epoxy resin, or an acrylic resin, a photocurable plastic, or the like. One sealing part 27-1 is formed in a circular frame shape so as to surround the outer periphery of the power generation part 24, and the other sealing part 27-2 is formed in a cylindrical shape so as to surround the inner periphery of the power generation part 24, The inner diameter of the sealing portion 27-2 is the same as that of the through hole 21a. In the second embodiment, these sealing portions 27-1 and 27-2 seal the gap between the planar electrode 23 and the planar electrode 26, as well as the lower surface of the planar electrode 23 and the upper surface of the planar electrode 26. However, in addition to the sealing portions 27-1 and 27-2, a dedicated spacer may be used in combination. .

The charge transport material 28 is composed of a liquid or gel containing a redox electrolyte, for example, an acetonitrile-based solvent containing iodine redox couple (I ⁻ / I ₃ ⁻ ), or a material obtained by adding a gelling agent thereto. The charge transport material 28 is filled in a space defined by the power generation unit 24, the planar electrode 26, and the sealing units 27-1 and 27-2.

  As can be seen from FIG. 4, the through hole 21 a of the transparent substrate 21, the through hole 23 a of the planar electrode 23, the inner hole of the inner sealing portion 27-2, the through hole 26 a of the planar electrode 26, and the through hole 25 a of the counter substrate 25. Are continuous in the cell thickness direction, and the continuous hole group forms a center hole SH.

  Although not shown, the negative electrode side terminal of the dye-sensitized solar cell 20 is connected to the innermost annular electrode line 22b of the current collecting electrode 22 and the inner periphery of the planar electrode 23 so as to be electrically connected to the center hole. SH is provided on the inner surface. The positive electrode side terminal of the dye-sensitized solar cell 20 is provided on the inner surface of the center hole SH so as to be electrically connected to the inner peripheral portion of the planar electrode 26.

  In the dye-sensitized solar cell 20 described above, desired photoelectric conversion is performed in the following cycle. That is, when light such as sunlight is irradiated on the transparent substrate 21, the light reaches the dye of the power generation unit 24 through the planar electrode 23 through each region ER of the current collecting electrode 22, and the dye is excited by light energy. The electrons are emitted from the planar electrode 23 and the radial electrode lines 22a and the annular electrode lines 22b of the current collecting electrode 22 via the porous semiconductor film of the power generation unit 24, and the electrons further move to the negative electrode. It moves to the planar electrode 26 via an external circuit connected between the side terminal and the positive electrode side terminal. The dye oxidized by emitting electrons receives the electrons from the charge transport material 28 to neutralize, and the charge transport material 28 oxidized by losing electrons receives the electrons transferred to the planar electrode 26 and is reduced.

  In short, the current generated by the dye sensitizing action when the power generation unit 24 is irradiated with light such as sunlight through the transparent substrate 21 and the planar electrode 23 can be taken out from the negative terminal and the positive terminal.

  In the dye-sensitized solar cell 20 described above, the current collecting electrode 22 is made of a material having a specific resistance lower than that of the planar electrode 23. It also plays a role in increasing photoelectric conversion efficiency by compensating for the effects.

  As described above, the collector electrode 22 is electrically connected to the radial electrode lines 22a and the radial electrode lines 22a extending radially outward from the cell center and outward from the cell center. Since the upper surface contour shape of the power generation unit 24 is circular, the upper surface contour shape of the power generation unit 24 is circular. Even in such a case, the radial electrode lines 22a and the annular electrode lines 22b of the current collecting electrode 22 are extended so as to correspond to almost the entire region of the upper surface contour shape (circular shape) of the power generation unit 24. The desired current collection can be performed with high efficiency through the annular electrode wire 22b.

  The areas of the plurality of regions ER surrounded by two line segments of the two adjacent radial electrode lines 22a of the current collecting electrode 22 and two line segments of the two adjacent annular electrode lines 22b are substantially matched. Therefore, the current generated in each of the portions corresponding to each region ER of the power generation unit 24 can be collected by four line segments defining the region ER under substantially the same resistance value. The current collection efficiency can be further increased by preventing a difference in current collection efficiency.

  Furthermore, since the interval between the annular electrode lines 22b of the current collecting electrode 22 is decreased from the cell center toward the outside, it is possible to easily make the areas of the respective regions ER substantially coincide with each other.

  In the above description, the outermost annular electrode line 22b of the collecting electrode 22 is positioned inside the outer sealing portion 27-1, and the innermost annular electrode line 22b is positioned inside the inner sealing portion 27-1. Although the example in which the current collecting electrode 12 is arranged on the upper side of the power generation part 24 so as to be located outside the power generation part 24 is illustrated, the current collecting electrode 22 has the outermost annular electrode line 22b as the outer sealing part 27-. 1 and the innermost annular electrode line 22b may be disposed above the inner sealing portion 27-2. In this case, a part of the surface of the outermost annular electrode line 12b of the current collecting electrode 12 and a part of the surface of the innermost annular electrode line 12b may be exposed.

  In the above description, the collector electrode 22 is disposed between the transparent substrate 21 and the planar electrode 23. However, the collector electrode 22 is disposed between the planar electrode 23 and the power generation unit 24. However, the same effect as described above can be obtained. In the case of this structure, since the charge transport material 28 is in contact with the current collecting electrode 22, when a material that can be deteriorated by the contact is used for the current collecting electrode 22, it is resistant to the charge transport material 28, and The current collecting electrode 22 may be covered with a material that does not impede electrical performance, for example, an insulating material such as glass frit or an organic polymer compound. Further, when a sufficient current collecting action can be expected with only the current collecting electrode 22, the planar electrode 23 can be eliminated. In this structure, a material that can be deteriorated by contact with the charge transport material 28 is collected. When used for the current electrode 22, the current collection electrode 22 is preferably covered with the same material as described above that is resistant to the charge transport material 28 and does not impair the current collection performance.

  Further, in the above description, the current collector electrode 22 is used as the negative electrode. However, a current collector electrode having the same configuration as the current collector electrode 22 may be used as the positive electrode. Specifically, a current collecting electrode having the same configuration as the current collecting electrode 22 is used in place of the flat electrode 26 that is the positive electrode, or the flat electrode 26 of the positive electrode on the two-layer structure described above is used. A collecting electrode having the same configuration as the collecting electrode 22 may be used. In this case, the technique described in the previous paragraph can be used to improve the resistance of the current collecting electrode to the charge transport material 28.

  Furthermore, in the above description, the radial electrode lines 22a and the annular electrode lines 22b of the collecting electrode 22 are described as being made as small as possible so as not to block the incidence of light such as sunlight. If the line width of the part existing in the position away from the negative electrode side terminal of the line 22a and the annular electrode line 22b is made larger than the line width of the part present in the position close to the negative electrode side terminal, the radial electrode line 22a and the annular electrode line 22b It is possible to reduce the electrical length of the portion located at a position away from the negative electrode side terminal and suppress the conduction loss due to the resistance value of the portion.

[Third Embodiment]
FIG. 5 is a top view of a cell of a dye-sensitized solar cell according to a third embodiment of the present invention.

  Similar to the cell structure of the second embodiment, the dye-sensitized solar cell 30 shown in FIG. 5 includes a transparent substrate 31, a current collecting electrode 32, a planar electrode (not shown), and a power generation unit (not shown). A cell structure including a counter substrate (not shown), a planar electrode (not shown), two sealing portions (not shown), a charge transport material (not shown), and a center hole SH. Yes.

  The difference between the cell structure of the third embodiment and the cell structure of the second embodiment is that the transparent substrate 31, the planar electrode, the power generation unit, the counter substrate, and the planar electrode each have a regular triangular top surface shape, It is in the point which changed the form of the current collection electrode 32 according to the upper surface outline shape of the electric power generation part.

  As shown by broken lines in FIG. 5, the current collecting electrode 32 is electrically connected to a plurality of (in the figure, 12) radial electrode lines 32a extending radially outward from the cell center and to each radial electrode line 32a. And a plurality (six in the figure) of annular electrode wires 32b that are concentrically arranged outward from the cell center and have a shape (regular triangle) similar to the upper surface contour shape (regular triangle) of the power generation unit; It is composed of

  Each radial electrode line 32a exists between the innermost annular electrode line 32b and the outermost annular electrode line 32b, and preferably does not protrude inward or outward from these annular electrode lines 32b. In the third embodiment, the innermost annular electrode wire 32b is used as a current extraction portion.

  The areas of the plurality of (60 in the figure) regions ER surrounded by two line segments of two adjacent radial electrode lines 32a and two line segments of two adjacent annular electrode lines 32b substantially coincide with each other. ing. In order to easily make the areas of the respective regions ER substantially coincide with each other, the adjacent interval between the annular electrode lines 32b decreases from the cell center toward the outside. Moreover, since the upper surface contour shape of the power generation unit is a regular triangle, each radial electrode line 32a is arranged at a position that divides the three sides of each annular electrode line 32b into four equal parts so that the area of each region ER can be easily adjusted. Has been.

  Since the other basic configuration is the same as the cell structure of the second embodiment, the description thereof is omitted.

  In the dye-sensitized solar cell 30 described above, the current collecting electrode 32 is made of a material having a specific resistance lower than that of the planar electrode. (Including)) to increase the photoelectric conversion efficiency.

  As described above, the collector electrode 32 is electrically connected to the plurality of radial electrode lines 32a extending radially outward from the cell center, and to each radial electrode line 32a, and outward from the cell center. The upper surface contour shape of the power generation unit is an equilateral triangle because the upper surface contour shape (regular triangle) of the power generation unit and the plurality of annular electrode wires 32b having a similar shape (regular triangle) are arranged concentrically. Even so, the radial electrode lines 32a and the annular electrode lines 32b of the current collecting electrode 32 are extended so as to correspond to almost the entire area of the upper surface contour shape (regular triangle) of the power generation unit, and the radial electrode lines 32a and 32a The desired current collection can be performed with high efficiency through each annular electrode line 32b.

  The areas of the plurality of regions ER surrounded by two line segments of the two adjacent radial electrode lines 32a of the collecting electrode 32 and two line segments of the two annular electrode lines 32b adjacent to each other are substantially matched. Therefore, the current generated in each of the portions corresponding to each region ER of the power generation unit can be collected by four line segments that define the region ER under substantially the same resistance value, thereby collecting the current for each region ER. The current collection efficiency can be further increased by preventing a difference in power efficiency.

  Further, since the interval between the annular electrode lines 22b of the current collecting electrode 32 is decreased from the center of the cell toward the outside, the areas of the respective regions ER can be easily matched.

  Note that all the modifications described in the last note of the description of the second embodiment can be adopted for the cell structure of the third embodiment.

[Fourth Embodiment]
FIG. 6 is a top view of a cell of a dye-sensitized solar cell according to the fourth embodiment of the present invention.

  Similar to the cell structure of the second embodiment, the dye-sensitized solar cell 40 shown in FIG. 6 includes a transparent substrate 41, a collecting electrode 42, a planar electrode (not shown), and a power generation unit (not shown). A cell structure including a counter substrate (not shown), a planar electrode (not shown), two sealing portions (not shown), a charge transport material (not shown), and a center hole SH. Yes.

  The difference between the cell structure of the fourth embodiment and the cell structure of the second embodiment is that the transparent substrate 41, the planar electrode, the power generation unit, the counter substrate, and the planar electrode have a regular hexagonal shape on the upper surface, It is in the point which changed the form of the current collection electrode 42 according to the upper surface outline shape of the electric power generation part.

  As shown by broken lines in FIG. 6, the current collecting electrode 42 is electrically connected to a plurality of (12 in the figure) radial electrode lines 42a extending radially outward from the cell center and to each radial electrode line 42a. And a plurality (six in the figure) of annular electrode wires 42b that are concentrically arranged outward from the cell center and have a shape (regular hexagon) similar to the upper surface contour shape (regular hexagon) of the power generation unit; It is composed of

  Each radial electrode line 42a exists between the innermost annular electrode line 42b and the outermost annular electrode line 42b, and preferably does not protrude inward or outward from these annular electrode lines 42b. In the fourth embodiment, the innermost annular electrode wire 32b is used as a current extraction portion.

  The areas of the plurality of (60 in the drawing) regions ER surrounded by two line segments of two adjacent radial electrode lines 42a and two line segments of two adjacent annular electrode lines 42b substantially coincide with each other. ing. In order to easily make the areas of the respective regions ER substantially coincide with each other, the adjacent interval between the annular electrode lines 42b decreases from the cell center toward the outside. Further, since the upper surface contour shape of the power generation unit is a regular hexagon, the adjacent angles of the radial electrode wires 42a are all equal (30 degrees in the figure) so that the area of each region ER can be easily adjusted.

  Since the other basic configuration is the same as the cell structure of the second embodiment, the description thereof is omitted.

  In the dye-sensitized solar cell 40 described above, the current collecting electrode 42 is made of a material having a specific resistance lower than that of the flat electrode. (Including)) to increase the photoelectric conversion efficiency.

  As described above, the collecting electrode 42 has a plurality of radial electrode lines 42a extending radially outward from the cell center, and is electrically connected to each radial electrode line 42a and outward from the cell center. The upper surface contour shape of the power generation section is a regular hexagon because the power generation section has a plurality of annular electrode wires 42b that are concentrically arranged and have a similar shape (regular hexagon) to the upper surface contour shape (regular hexagon) of the power generation section. Even so, the radial electrode wires 42a and the annular electrode wires 42b of the current collecting electrode 42 are extended so as to correspond to almost the entire area of the upper surface contour shape (regular hexagon) of the power generation unit, and the radial electrode wires 42a and 42a The desired current collection can be performed with high efficiency through each annular electrode wire 42b.

  The areas of the plurality of regions ER surrounded by two line segments of the two adjacent radial electrode lines 42a of the collecting electrode 42 and two line segments of the two annular electrode lines 42b adjacent to each other are substantially matched. Therefore, the current generated in each of the portions corresponding to each region ER of the power generation unit can be collected by four line segments that define the region ER under substantially the same resistance value, thereby collecting the current for each region ER. The current collection efficiency can be further increased by preventing a difference in power efficiency.

  Further, since the interval between the annular electrode lines 42b of the current collecting electrode 42 is decreased from the center of the cell toward the outside, the areas of the respective regions ER can be easily matched.

  Note that all the modifications described in the last note of the description of the second embodiment can be adopted for the cell structure of the fourth embodiment.

[Other Embodiments]
In the first to fourth embodiments, the upper surface contour shape is an example in which the collecting electrode, which is the feature of the present invention, is applied to a cell structure including a power generation unit having a circular shape, a regular triangle shape, and a regular hexagonal shape. In addition to the cell structure with a quadrangular power generation part, the collector electrode of a shape and configuration corresponding to the top surface contour shape is adopted even for a cell structure with a power generation part having a top surface contour shape other than these By doing so, the same effect as described above can be obtained.

  In the third and fourth embodiments, the cell structure including the power generation unit having the regular outline and the regular hexagonal shape of the top surface is described using the cell structure of the second embodiment. Needless to say, the same effect as described above can be obtained even if the cell structure is the same as that of the embodiment.

It is a top view of the cell of the dye-sensitized solar cell which shows 1st Embodiment of this invention. It is the aa line longitudinal cross-sectional view of FIG. It is a top view of the cell of the dye-sensitized solar cell which shows 2nd Embodiment of this invention. It is the bb line longitudinal cross-sectional view of FIG. It is a top view of the cell of the dye-sensitized solar cell which shows 3rd Embodiment of this invention. It is a top view of the cell of the dye-sensitized solar cell which shows 4th Embodiment of this invention.

Explanation of symbols

  10, 20, 30, 40 ... dye-sensitized solar cell, 11, 21, 31, 41 ... transparent substrate, 12, 22, 32, 42 ... current collecting electrode, 12a, 22a, 32a, 42a ... radial electrode wire, 12b, 22b, 32b, 42b ... annular electrode wire, ER ... area, 13, 23 ... plane electrode, 14, 24 ... power generation unit, 15, 25 ... counter substrate, 16, 26 ... plane electrode, 17, 27-2, 27-2: Sealing part, 18, 28: Charge transport material.

Claims (4)

A dye-sensitized solar cell having a cell structure including a power generation unit, a negative electrode, and a positive electrode,
At least one of the positive electrode side electrode and the negative electrode side electrode has a plurality of radial electrode lines extending radially outward from the cell center, electrically connected to each radial electrode line, and concentric from the cell center toward the outer side. A collector electrode composed of a plurality of annular electrode wires arranged in a shape and having a shape similar to the upper surface contour shape of the power generation unit,
A dye-sensitized solar cell characterized by the above. The area of each of the plurality of regions surrounded by the two line segments of the two adjacent radial electrode lines of the collecting electrode and the two line segments of the two annular electrode lines adjacent to each other is substantially the same.
The dye-sensitized solar cell according to claim 1. The distance between adjacent annular electrode lines of the collecting electrode decreases from the center of the cell toward the outside.
The dye-sensitized solar cell according to claim 2. At least one of the positive electrode side electrode and the negative electrode side electrode is provided with a planar electrode electrically connected to each radial electrode line and each annular electrode line of the current collecting electrode in addition to the current collecting electrode.
The dye-sensitized solar cell according to any one of claims 1 to 3, wherein:

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