JP2009009948A - Dye-sensitized solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dye-sensitized solar cell which has an energy conversion efficiency excellent in a practical level, and allows for a stable power generation. <P>SOLUTION: The dye-sensitized solar cell 10 includes: an optical electrode WE having a semiconductor electrode 2 and a transparent electrode 1 disposed on a light receiving surface F2 of the semiconductor electrode 2; and a counter electrode CE, wherein the semiconductor electrode 2 and the counter electrode are arranged oppositely through an electrolyte E. The light receiving surface of the semiconductor electrode 2 is so formed that the incident angle θ of light incident, from the normal line direction of a light receiving surface F1 of the transparent electrode 1, on the light receiving surface F2 of the semiconductor electrode 2 is 30 to 80°. The light receiving surface F2 of the semiconductor electrode 2 is an interface of the transparent electrode 1 and the semiconductor electrode 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  In recent years, various developments of solar cells have been promoted with increasing interest in global warming and energy problems. Among the solar cells, in order to realize the practical use of the dye-sensitized solar cell, it is necessary to improve the energy conversion efficiency (photoelectric conversion efficiency) to at least the same level as that of the amorphous silicon solar cell.

  For example, an energy conversion efficiency of about 8% or more is required for a dye-sensitized solar cell module having a size of about 1 m × 1 m. Therefore, a dye-sensitized solar cell (hereinafter simply referred to as a “cell”), which is a structural unit of a dye-sensitized solar cell module of such a scale, is connected between cells in order to connect the cells to each other. Considering the loss of the light receiving area caused by the frame portion formed in the frame and the loss of the light receiving area caused by the comb electrode provided to improve the current collecting efficiency, an energy conversion efficiency exceeding about 8% is required. . For example, when a module having the above-mentioned value of energy conversion efficiency is configured using a cell having a size of about 10 cm × 10 cm, each cell is required to have an energy conversion efficiency of about 10% or more.

The energy conversion efficiency of the dye-sensitized solar cell includes incident light intensity I ₀ [mWcm ⁻² ], open-circuit voltage V _oc [V], short-circuit current density I _sc [mAcm ⁻² ], fill factor F.R. F. It is represented by the following formula (1) using (Fill Factor).
Energy conversion efficiency = (V _oc × I _sc × FF) / I ₀ (1)

As apparent from the above equation (1), in order to improve the energy conversion _efficiency, V _{oc, I sc} and F. F. However, it is not easy to improve them. Therefore, various attempts have been made to improve the energy conversion efficiency by improving the utilization rate (quantum efficiency) of incident light in the semiconductor electrode.

  For example, by increasing the thickness of the semiconductor electrode containing the dye, the optical path of incident light can be lengthened to improve the utilization rate of incident light. However, increasing the thickness of the semiconductor electrode increases the electrical resistance of the semiconductor electrode, increases the disappearance of carriers in the electrode, increases the ion diffusion resistance in the electrolyte present in the nanopores in the electrode, The energy conversion efficiency will decrease. Therefore, attempts have been made to improve the utilization rate of incident light in the semiconductor electrode under the condition that the thickness of the semiconductor electrode is reduced (15 μm or less).

  For example, a dye-sensitized solar cell intended to improve the utilization rate by scattering incident light incident on a semiconductor electrode by mixing large and small semiconductor particles in the semiconductor electrode. Proposed. In Japanese Patent No. 2664194, a semiconductor electrode made of a polycrystalline metal oxide semiconductor and having a thickness of about 20 μm is used. The surface roughness coefficient of the surface is larger than 20 and a dye is formed on the surface. A dye-sensitized solar cell that can achieve a high energy conversion efficiency value of about 12% has been proposed.

  However, in the conventional dye-sensitized solar cell in which a semiconductor particle having a large particle size and a small semiconductor particle are mixed in a semiconductor electrode, as a result of light scattering by a large semiconductor crystal particle, as compared with a case where there is no large semiconductor particle. Thus, the optical path length passing through the semiconductor electrode becomes longer and the light utilization rate increases, but since the scattering phenomenon is used to the last, there is a problem that some of the light passes through the semiconductor electrode. In addition, when there are many large semiconductor crystal particles, there is a problem that the total surface area of the semiconductor surface to which the dye is adsorbed is reduced, the light absorption rate is reduced, and the photoelectric conversion efficiency is lowered.

  In addition, the dye-sensitized solar cell described in Japanese Patent No. 2664194 does not have a separate current collector on the transparent conductive film, and electrons injected from the dye excited by absorbing light into the metal oxide semiconductor. Is collected only by the transparent conductive film and taken out as electric power. However, when the area of the battery is larger than 1 cm × 1 cm due to the conductivity limit of the transparent conductive film, the resistance loss increases, and the conversion factor is lowered by reducing the form factor. Therefore, when the area of the battery is larger than 1 cm × 1 cm, it is necessary to reduce the resistance loss by providing a current collecting wire such as Ag at a constant interval. However, in this case, there will be a problem of corrosion of the current collector due to the electrolytic solution. At the same time as the protective layer for protecting the current collector is installed, it is necessary to change the electrolyte to a component composition that does not corrode the current collecting electrode. There is. The installation of the current collecting electrode and the protective layer reduces the effective photoelectric conversion area of the battery. Moreover, the change of the electrolyte component leads to a decrease in conversion efficiency at present.

  Further, when a solar cell panel having a larger area is configured by combining a plurality of solar cells having an area of 10 cm × 10 cm, each of the 10 cm × 10 cm arranged adjacent to each other due to a problem in wiring extraction or exterior Since a frame portion that does not contribute to photoelectric conversion is formed for each solar cell having an area, the effective area for photoelectric conversion is further reduced. Further, when a solar cell module is configured by combining a plurality of the above-described solar cell panels, the frame portion is also formed between the solar cell panels, so that the loss of the effective area for photoelectric conversion further increases. . For this reason, even if the technology of Japanese Patent No. 2664194 is used, there is a problem that it is very difficult to achieve a practical level of conversion efficiency in a dye-sensitized solar cell.

  The present invention has been made in view of the above-described problems of the prior art, and has a dye-sensitized solar cell and a dye-sensitized solar cell that have a practical level of energy conversion efficiency and can stably generate power. An object is to provide a battery module.

  As a result of intensive research to achieve the above object, the present inventors have made light incident from the normal direction of the electrode surface (light receiving surface) when entering the semiconductor electrode (hereinafter referred to as “perpendicular incidence”). In the dye-sensitized solar cell, in the dye-sensitized solar cell, light is directed in the normal direction of the electrode surface, despite the fact that it is effective in improving the energy conversion efficiency. On the other hand, when incident at an angle of incidence of 30 to 80 ° (hereinafter referred to as “oblique incidence”), the incident light utilization rate is improved and the amount of power generation per unit effective area is improved as compared to the case of vertical incidence. I found.

For example, a photoelectrode having a structure in which a TiO ₂ semiconductor electrode having an area contributing to power generation on the light receiving surface of 50 mm ² and a thickness of 20 μm is formed on a glass substrate having a thickness of 1.1 mm, and an iodine-based redox solution And a counter electrode CE having a structure in which a Pt thin film (film thickness: 3 nm) is deposited on a fluorine-doped SnO ₂ coated glass substrate having the same shape and size as the above glass substrate. Regarding the battery 100 (having the same configuration as that of the dye-sensitized solar cell UC shown in FIG. 6), the light incident angle dependency of the energy conversion efficiency was measured, and the result shown in the graph of FIG. 14 was obtained. In addition, η shown on the vertical axis in FIG. 14 indicates “effective energy conversion efficiency” described later. As is clear from the results shown in FIG. 14, it was confirmed that energy conversion efficiency was improved when light was incident obliquely at an incident angle of 30 to 80 ° with respect to the normal direction of the electrode surface.

Further, with respect to this dye-sensitized solar cell 100, the results of measurement of current-voltage characteristics and η when light is incident at an incident angle of about 45 ° and from the normal direction are shown in FIG. And shown in (b). FIG. 15A is a graph showing current-voltage characteristics and energy conversion efficiency when light is incident at an incident angle of about 45 ° with respect to the normal direction of the electrode surface of the dye-sensitized solar cell 100. FIG. 15B is a graph showing current-voltage characteristics and energy conversion efficiency when the light is incident from the normal direction of the electrode surface of the dye-sensitized solar cell 100. Here, the measurement conditions were as follows: irradiation intensity at the light receiving surface of the semiconductor electrode: 4.2 mW / cm ² , measurement temperature in both cases of measurement of the battery characteristics of FIG. 15A and measurement of the battery characteristics of FIG. 27.8 ° C. 15A, the maximum value of the obtained energy conversion efficiency is 4.3140% (short-circuit current I _sc ; 0.3030 mA, open-circuit voltage Voc; 0.6024 V, fill factor) F. F .; 0.7289). On the other hand, in the measurement of the battery characteristics of FIG. 15B, the maximum value of the obtained energy conversion efficiency is 3.7080% (short-circuit current I _sc ; 0.2427 mA, open-circuit voltage Voc; 0.5880 V, fill factor) F.F .; 0.8875).

  The inventors have found that the above is extremely effective in improving the energy conversion efficiency of the dye-sensitized solar cell and the dye-sensitized solar cell module, and have reached the present invention.

  That is, the dye-sensitized solar cell of the present invention has a semiconductor electrode and a photoelectrode having a transparent electrode disposed on the light receiving surface thereof, and a counter electrode, and the semiconductor electrode and the counter electrode are interposed via an electrolyte. A dye-sensitized solar cell disposed opposite to the light-receiving surface of the semiconductor electrode so that the incident angle of light incident on the light-receiving surface of the semiconductor electrode from the normal direction of the light-receiving surface of the transparent electrode is 30 to 80 ° A surface is formed.

  As described above, the light traveling direction of light incident from the normal direction of the light receiving surface of the transparent electrode is used as a reference, and the light receiving surface of the semiconductor electrode is inclined with respect to the light receiving surface of the transparent electrode, so that the light is inclined to the electrode surface of the semiconductor electrode By adopting the structure for incidence, a sufficiently long optical path can be secured in the semiconductor electrode even if the thickness of the semiconductor electrode is reduced.

That is, when the thickness of the semiconductor electrode is reduced, (1) photoexcitation of the dye in the semiconductor electrode and electron injection into the semiconductor can be efficiently performed in a region in the vicinity of the transparent electrode having a small electrical resistance and a small amount of carrier loss. (2) A dye reduction reaction in which a redox species such as I ⁻ / I ₃ ^— acts on a dye after photoexcitation and electron injection into a semiconductor is performed in a region near an electrolyte having a small ion diffusion resistance. A sufficiently long optical path in the semiconductor electrode can be secured in the semiconductor electrode without losing the advantage of being able to perform efficiently, so that the utilization rate of incident light is improved, and consequently, per unit effective area of the semiconductor electrode. Energy conversion efficiency can be improved. Specifically, the dye-sensitized solar cell of the present invention performing oblique incidence as compared with a conventional dye-sensitized solar cell performing normal incidence has an energy conversion efficiency per unit effective area of the semiconductor electrode of 5 to 5. It can be improved by 50%.

  The above results are characteristics of a dye-sensitized solar cell that cannot be obtained when light is incident obliquely on a normal solid pn junction solar cell such as a Si solar cell.

In the present invention, the “effective area of the semiconductor electrode” means that the actual area of the light receiving surface of the semiconductor electrode is S _0, and the incidence of light incident on the light receiving surface of the semiconductor electrode from the normal direction of the light receiving surface of the transparent electrode When the angle is θ, the area represented by S ₀ cos θ is shown. That is, when the light receiving surface of the semiconductor electrode is inclined with an inclination angle θ with respect to the light receiving surface of the transparent electrode or the installation surface on which the dye-sensitized solar cell is installed, the effective area of the semiconductor electrode is actually It shows the orthogonal projection of the area of the area S ₀ of the. In the present invention, “energy conversion efficiency per unit effective area of the semiconductor electrode” is described as “effective energy conversion efficiency” in the following description.

  Here, when the incident angle of light incident on the light receiving surface of the semiconductor electrode is less than 30 ° as measured from the normal direction of the light receiving surface of the transparent electrode, there are few merits due to the oblique incidence of light, and incident light is incident on the light receiving surface. The “effective energy conversion efficiency” cannot be improved by offsetting the decrease in light energy per unit area compared with the case of vertical incidence. On the other hand, when the incident angle of the light incident on the light receiving surface of the semiconductor electrode exceeds 80 ° as measured from the normal direction of the light receiving surface of the transparent electrode, the “effective energy conversion efficiency” is improved for the following two reasons. I can't hope. That is, one reason for this is that when the light receiving surface of the transparent electrode and the light receiving surface of the semiconductor electrode are parallel, if the incident angle exceeds 80 °, the reflection on the surface of the transparent electrode becomes significant. Is difficult to reach the semiconductor electrode. Another reason is that when light enters the transparent electrode perpendicularly and the semiconductor electrode is incident at an angle of incidence exceeding 80 °, the reflection loss at the interface between the transparent electrode and the semiconductor electrode. In addition, the scattering loss increases. From the same viewpoint as described above, the incident angle of light incident on the light receiving surface of the semiconductor electrode from the normal direction of the light receiving surface of the transparent electrode is more preferably 40 to 75 °, and 50 to 70 °. Is more preferable.

Furthermore, the thickness of the semiconductor electrode of the dye-sensitized solar cell of the present invention is preferably 5 to 30 μm, more preferably 5 to 15 μm, and still more preferably 8 to 13 μm. When the thickness of the semiconductor electrode is less than 5 μm, the amount of dye adsorbed decreases, and the tendency that light cannot be effectively absorbed increases. On the other hand, when the thickness of the semiconductor electrode exceeds 30 μm, the electrical resistance increases and the amount of loss of carriers injected into the semiconductor increases, and the ion diffusion resistance increases and photoexcitation causes electron injection into the semiconductor. The later injection of electrons from I ⁻ to the dye impedes the export of I ₃ ^{− to} the counter electrode, and the tendency for the output characteristics of the battery to decrease increases.

  The dye-sensitized solar cell of the present invention includes a semiconductor electrode and a photoelectrode having a transparent electrode disposed on the light receiving surface thereof, and a counter electrode, and the semiconductor electrode and the counter electrode are interposed via an electrolyte. It is a dye-sensitized solar cell arranged oppositely, and the transparent electrode has an external angle so that the incident angle of light traveling through the transparent electrode and entering the light receiving surface of the semiconductor electrode is 30 to 80 °. The light guide means for changing the traveling direction of the light incident on the light receiving surface of the transparent electrode is formed.

  As described above, the light guide means for changing the traveling direction of the light incident on the light receiving surface of the transparent electrode from the outside of the battery is provided on the upper portion of the transparent electrode, and the light incident perpendicularly on the light receiving surface of the transparent electrode is provided in the semiconductor. By adopting a configuration in which the light is incident obliquely on the light receiving surface of the electrode, a sufficiently long optical path can be secured in the semiconductor electrode even if the thickness of the semiconductor electrode is reduced, as in the dye-sensitized solar cell described above. it can. Therefore, the utilization factor of incident light can be improved, and consequently, the effective energy conversion efficiency can be improved.

  In addition, in the dye-sensitized solar cell of the present invention, in the case of the battery having the configuration in which the light guide means is provided as described above, it becomes a reference for forming the light receiving surface of the transparent electrode or the light receiving surface of the semiconductor electrode. “The traveling direction of light incident on the light receiving surface of the transparent electrode from the outside” indicates the normal direction of the light receiving surface of the transparent electrode when the light receiving surface of the transparent electrode is flat (for example, in FIG. On the other hand, when the light-receiving surface of the transparent electrode is not flat and the light-receiving surface of the semiconductor electrode is flat, the normal direction of the light-receiving surface of the semiconductor electrode is indicated (for example, a diagram to be described later) 3 (see the surface F1 and the surface F2 shown in FIG. 3). Furthermore, when the light receiving surface of the transparent electrode and the light receiving surface of the semiconductor electrode are not flat, a flat virtual surface is provided as a virtual light receiving surface inside the transparent electrode or the semiconductor electrode, and the method of this virtual light receiving surface is used. It is assumed that the linear direction is the traveling direction of light incident from the outside, and the light receiving surface of the actual transparent electrode or the light receiving surface of the semiconductor electrode is designed based on this.

  Furthermore, in this case, the incident angle of light incident on the electrode surface of the semiconductor electrode from the light guide means can be controlled more precisely and easily. As a result, when a plurality of current collecting electrodes (comb-shaped electrodes) are arranged inside the semiconductor electrode, the traveling direction of incident light entering the semiconductor electrode can be adjusted to avoid this, and the current collecting electrodes ( It is possible to easily scale up a laboratory scale test cell to a practical scale cell without degrading the effective energy conversion efficiency due to the comb-shaped electrode).

However, in the dye-sensitized solar cell of the present invention, when the light guide means is provided as described above and the light receiving surface of the semiconductor electrode is flat, the above-mentioned “effectiveness of the semiconductor electrode” area "is equal to the actual area S _0. Therefore, in the present invention, the “effective energy conversion efficiency” in the case of the solar cell having such a configuration indicates energy conversion efficiency per S ₀ instead of S ₀ cos θ.

  Even in the above case, the incident angle of light incident on the light receiving surface of the semiconductor electrode from the normal direction of the light receiving surface of the transparent electrode or the normal direction of the light receiving surface of the semiconductor electrode is 40 to 75 °. Is more preferable, and it is still more preferable that it is 50-70 degrees. The thickness of the semiconductor electrode in this case is also preferably 5 to 30 μm, more preferably 5 to 15 μm, and still more preferably 8 to 13 μm.

  The dye-sensitized solar cell of the present invention includes a semiconductor electrode and a photoelectrode having a transparent electrode disposed on the light receiving surface thereof, and a counter electrode, and the semiconductor electrode and the counter electrode are interposed via an electrolyte. A dye-sensitized solar cell disposed opposite to the light-receiving surface of the semiconductor electrode, and a plurality of current collecting electrodes are provided on the light-receiving surface of the semiconductor electrode, and the light that travels through the transparent electrode and enters the light-receiving surface of the semiconductor electrode. The light receiving surface of the semiconductor electrode is formed so that the incident angle is 30 to 80 °, and the light is selectively irradiated to a region of the light receiving surface of the semiconductor electrode where the current collecting electrode is not formed. Thus, the light receiving surface of the transparent electrode is formed.

  In the above dye-sensitized solar cell as well, the reference direction when forming the light receiving surface of the transparent electrode or the light receiving surface of the semiconductor electrode is “the traveling direction of light incident on the light receiving surface of the transparent electrode from the outside”. Indicates the normal direction of the light-receiving surface of the transparent electrode when the light-receiving surface of the transparent electrode is flat. On the other hand, when the light-receiving surface of the transparent electrode is not flat but the semiconductor electrode is flat, the semiconductor The normal direction of the light-receiving surface of an electrode is shown. Furthermore, when the light receiving surface of the transparent electrode and the light receiving surface of the semiconductor electrode are not flat, a flat virtual surface is provided as a virtual light receiving surface inside the transparent electrode or the semiconductor electrode, and the method of this virtual light receiving surface is used. The linear direction is set as the traveling direction of light incident from the outside, and the light receiving surface of the actual transparent electrode or the light receiving surface of the semiconductor electrode is designed on the basis of this (refer to a virtual light receiving surface FP1 shown in FIG. 9 described later). .

  By forming the light-receiving surface of the semiconductor electrode and the light-receiving surface of the transparent electrode so as to satisfy the above conditions, the incident angle of light incident on the electrode surface of the semiconductor electrode can be controlled more precisely and easily. Is possible. As a result, even if a plurality of collecting electrodes (comb-shaped electrodes) are arranged inside the semiconductor electrode, the traveling direction of incident light entering the semiconductor electrode can be adjusted so as to avoid this, and the collecting electrode ( It is possible to easily scale up a laboratory scale test cell to a practical scale cell without degrading the effective energy conversion efficiency due to the comb-shaped electrode).

  Even in the above case, the incident angle of light incident on the light receiving surface of the semiconductor electrode is more preferably 40 to 75 °, and still more preferably 50 to 70 °. The thickness of the semiconductor electrode in this case is also preferably 5 to 30 μm, more preferably 5 to 15 μm, and still more preferably 8 to 13 μm.

  Furthermore, the dye-sensitized solar cell module of the present invention includes a semiconductor electrode and a photoelectrode having a transparent electrode disposed on the light receiving surface thereof, and a counter electrode, and the semiconductor electrode and the counter electrode are interposed via an electrolyte. A plurality of dye-sensitized solar cells that are arranged opposite each other on the base, and are incident on each dye-sensitized solar cell from the normal direction of the base installation surface. Each dye-sensitized solar cell is arranged so that the incident angle of light to be 30 to 80 °.

  In this way, the direction of light incident on each dye-sensitized solar cell constituting the module is defined as a standard from the normal direction of the base mounting surface, and each dye-sensitized solar cell is inclined to each semiconductor. By adopting a configuration in which light is obliquely incident on the electrode surface of the electrode, a sufficiently long optical path is ensured in the semiconductor electrode even if the thickness of the semiconductor electrode is reduced, as in the dye-sensitized solar cell described above. be able to. Therefore, the utilization factor of incident light of each dye-sensitized solar cell can be improved, and as a result, the energy conversion efficiency of the entire module can be improved. In this case, since the dye-sensitized solar cell can be produced by using a structurally stable one, the entire module can stably generate power with high effective energy conversion efficiency. Become.

  Further, in this case, it is also possible to make light reflected on the light receiving surface of the semiconductor electrode of one dye-sensitized solar cell obliquely enter the light receiving surface of the semiconductor electrode of another dye-sensitized solar cell. Therefore, it becomes possible to obtain a large antireflection effect as a whole module.

  In this case as well, the incident angle of light incident on each dye-sensitized solar cell from the normal direction of the mounting surface of the base is more preferably 40 to 75 °, and more preferably 50 to 70 °. Is more preferable. Moreover, it is preferable that the thickness of a semiconductor electrode is 5-30 micrometers, It is more preferable that it is 5-15 micrometers, It is still more preferable that it is 8-13 micrometers.

  As described above, according to the dye-sensitized solar cell and the dye-sensitized solar cell module of the present invention, a sufficient incident light utilization rate can be reliably ensured even when a thin semiconductor electrode is used. Even in the case of scale-up or modularization, it is possible to easily reduce the incident light utilization rate decrease due to the decrease in the light receiving area. Therefore, it is possible to provide a dye-sensitized solar cell and a dye-sensitized solar cell module that have excellent energy conversion efficiency comparable to that of an amorphous silicon solar cell and that can stably generate power.

  Hereinafter, preferred embodiments of the dye-sensitized solar cell and the dye-sensitized solar cell module of the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

[First embodiment]
FIG. 1 is a schematic cross-sectional view showing a first embodiment of the dye-sensitized solar cell of the present invention. As shown in FIG. 1, the dye-sensitized solar cell 10 of the present embodiment is a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. And a counter electrode CE and an electrolyte E filled in a gap formed by the spacer S between the photoelectrode WE and the counter electrode CE. The dye-sensitized solar cell 10 generates electrons in the semiconductor electrode 2 by light L10 that is transmitted through the transparent electrode 1 and irradiated onto the semiconductor electrode 2. The electrons generated in the semiconductor electrode 2 are collected by the transparent electrode 1 and taken out to the outside.

  Here, as shown in FIG. 1, in the photoelectrode WE of the dye-sensitized solar cell 10, when the traveling direction of the light L10 incident from the normal direction of the light receiving surface F1 of the transparent electrode 1 is used as a reference, The semiconductor electrode 2 is formed so that the incident angle θ of the light L10 incident on the light receiving surface F2 of the semiconductor electrode from the normal direction of the light receiving surface F1 of the transparent electrode 1 is 30 to 80 °. That is, the electrode layer is formed in a sawtooth shape when the semiconductor electrode 2 is viewed from the cross-sectional direction. In addition, the contact surface of the transparent electrode 1 with the semiconductor electrode 2 is also formed with a sawtooth groove in accordance with the shape of the semiconductor electrode 2. Thereby, the light L10 incident from the outside is obliquely incident on the light receiving surface F2. And even if the thickness of the semiconductor electrode 2 is reduced, a sufficiently long optical path can be secured in the semiconductor electrode. Therefore, the utilization factor of incident light can be improved and the effective energy conversion efficiency can be improved. For example, the energy conversion efficiency about 1.2 times that of a conventional dye-sensitized solar cell having the same area can be obtained when θ = 45 ° due to the incident angle dependency of the photovoltaic force. In addition, when θ = 70 °, energy conversion efficiency about 1.5 times that of a conventional dye-sensitized solar cell having the same effective area can be obtained.

  In the dye-sensitized solar cell 10 shown in FIG. 1, the counter electrode CE is also formed with a sawtooth groove in which the surface F3 on the side in contact with the electrolyte E matches the shape of the semiconductor electrode 2. Thereby, in FIG. 1, the period of the serrated irregularities is about several millimeters, and the distance between the photoelectrode WE and the counter electrode CE is about 50 to 100 μm. Accordingly, the dye-sensitized solar cell 10 of FIG. 1 is drawn in an emphasized manner in the longitudinal direction (the traveling direction of the light L10). Actually, the surface F3 of the counter electrode CE is serrated in accordance with the shape of the semiconductor electrode 2, so that the counter electrode CE and the photoelectrode WE are arranged in parallel with the electrolyte E layer interposed therebetween, and uniform between them. A parallel electric field can be generated. If the shape of the surface F3 on the electrolyte E side of the counter electrode CE is flat, the electric field is concentrated on the convex portion on the photoelectrode side, and stable operation cannot be performed.

The structure of the transparent electrode 1 is not specifically limited, The transparent electrode mounted in a normal dye-sensitized solar cell can be used. For example, a transparent substrate (not shown) such as a glass substrate coated with a so-called transparent conductive film (see FIG. 2) that transmits light can be used. For example, fluorine-doped SnO ₂ coated glass, ITO coated Glass, ZnO: Al coated glass or the like is used. Moreover, the semiconductor used as the constituent material of the semiconductor electrode 2 is not specifically limited, An oxide semiconductor, a sulfide semiconductor, etc. can be used. As the oxide semiconductor, for _example, a _{TiO 2, ZnO, SnO 2,} Nb 2 O 5, In 2 O 3, WO 3, ZrO 2, La 2 O 3, Ta 2 O 5, SrTiO 3, BaTiO 3 , etc. be able to. For example, CdS can be used as the sulfide semiconductor. In addition to the above semiconductor, Si, GaAs, or the like can be used. Moreover, the pigment | dye contained in the semiconductor electrode 2 is not specifically limited, For example, a ruthenium complex, a metal phthalocyanine, etc. can be used.

In addition, the constituent material of the counter electrode CE is not particularly limited. For example, a metal thin film electrode such as Pt may be formed on the same transparent conductive film as the transparent electrode 1 described above, and the metal thin film electrode may be arranged facing the electrolyte E side. Furthermore, the composition of the electrolyte E is not particularly limited as long as it contains a redox species for reducing the dye after photoexcitation and electron injection into the semiconductor, but a redox species such as I ⁻ / I ₃ ⁻ is used. An iodine redox solution containing is preferably used. The constituent material of the spacer S is not particularly limited, and for example, silica beads or the like can be used.

Next, a method for manufacturing the dye-sensitized solar cell 10 of FIG. 1 will be described. In FIG. 2, an example of the manufacturing process of the photoelectrode WE of the dye-sensitized solar cell 10 of FIG. 1 is shown. First, the transparent electrode 1 can be formed using a known method such as spray coating the transparent conductive film 3 such as fluorine-doped SnO ₂ described above on a substrate 4 such as a glass substrate. At this time, the shape of the surface F4 on the side of the substrate 4 on which the transparent conductive film 3 is formed has a sawtooth cross section according to the value of the incident angle θ of light incident on the light receiving surface F2 of the semiconductor electrode 2 after completion. To form. The method for forming the surface of the substrate 4 in such a shape is not particularly limited. For example, the shape of a mold used when forming the substrate 4 by casting may be matched, and the substrate 4 is formed in a substantially rectangular parallelepiped shape. One side of the substrate may be cut into the above shape.

Next, as shown in FIG. 2, the semiconductor electrode 2 is formed by depositing a semiconductor Vs such as TiO ₂ in a film shape on the transparent conductive film 3 of the transparent electrode 1. A known method can be used as a method of depositing a semiconductor film on the transparent conductive film 3. For example, a physical vapor deposition method such as electron beam vapor deposition, resistance heating vapor deposition, sputter vapor deposition, or cluster ion beam vapor deposition may be used. Metal or the like is evaporated in a reactive gas such as oxygen, and the reaction product is converted into the transparent conductive film 3. A reactive vapor deposition method may be used. Furthermore, chemical vapor deposition such as CVD can be used by controlling the flow of the reaction gas.

  At this time, the incident angle θvs of the vapor deposition particles with respect to the normal direction of the surface F4 on the side of the substrate 4 on which the transparent conductive film 3 is formed is preferably 30 ° to 80 °. It is more preferable that the value is the same. Thus, the semiconductor electrode layer (deposited film) formed on the transparent conductive film 3 on the surface F4 is a columnar aggregate in which the deposited semiconductor particles have an inclination of 15 to 40 ° with respect to the normal direction of the light receiving surface F4. The body is formed to have a plurality of adjacent structures. The semiconductor electrode layer having the columnar structure has a larger surface area than the semiconductor electrode layer formed by vapor deposition of vapor deposition particles from the normal direction of the light receiving surface F4, and can increase the pigment content. Therefore, battery output and energy conversion efficiency can be improved. When the incident angle θvs of the vapor deposition particles is less than 30 °, the self-shielding effect in the vapor deposition is not significant, so that it is difficult to form a clear columnar structure. On the other hand, if the incident angle θvs of the vapor deposition particles exceeds 80 °, the film has a very sparse structure, and the mechanical strength may be lowered and the film may not be used.

  The method for adjusting the incident angle θvs of the vapor deposition particles to 30 to 80 ° is not particularly limited. For example, in the vapor deposition apparatus, the substrate 4 is previously tilted at a predetermined angle with respect to the traveling direction of the vapor deposition particles. Alternatively, the substrate 4 may be relatively moved at a high speed with respect to the vapor deposition particle supply source. Further, two vapor deposition particle supply sources are provided, and the incident direction of the vapor deposition particles with respect to the surface F4 is set in two directions. May be deposited at the same time. Further, at the time of vapor deposition, the specific surface area may be increased by gradually moving the substrate or the supply source of the vapor deposition particles in a plane direction perpendicular to the incident direction of the vapor deposition particles to deposit the semiconductor particles in a spiral shape.

  Next, after forming a semiconductor vapor deposition film to be the semiconductor electrode 2 on the transparent conductive film 3, a heat treatment may be applied to the semiconductor vapor deposition film under a predetermined temperature condition to cause phase transition as necessary. Thereby, for example, when the semiconductor vapor deposition film is formed in an amorphous phase state, it can be crystallized into an anatase phase. As a result, the efficiency of electron injection from the dye to the semiconductor is improved by the formation of a clear band structure by crystallization, the growth of crystal grains of the semiconductor and the accompanying improvement in the bonding between the crystal grains, or the semiconductor deposition The movement of electrons in the film is facilitated, and the energy conversion efficiency can be further improved. Furthermore, when the above heat treatment is performed in a non-oxidizing atmosphere, a semiconductor vapor deposition film with a large amount of oxygen defects can be obtained, and the electric conductivity of the semiconductor vapor deposition film is increased, and the energy conversion efficiency can be further improved.

  Next, a dye is contained in the semiconductor vapor deposition film by a known method such as an immersion method to complete the semiconductor electrode 2. At this time, in addition to the pigment, a metal such as silver or a metal oxide such as alumina may be contained in the deposited film as necessary. After producing the photoelectrode WE in this manner, a counter electrode CE is produced by a known method, and this, the photoelectrode WE, and the spacer S are assembled as shown in FIG. The dye-sensitized solar cell 10 is completed.

[Second Embodiment]
Hereinafter, a second embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 3 is a schematic cross-sectional view showing a second embodiment of the dye-sensitized solar cell of the present invention.

  As shown in FIG. 3, the dye-sensitized solar cell 11 of the present embodiment is a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. The counter electrode CE and the electrolyte E filled in the gap formed between the photoelectrode WE and the counter electrode CE by the spacer S. This dye-sensitized solar cell 11 has the same configuration as a conventional dye-sensitized solar cell except for the optical waveguide layer 5 (light guide means) provided on the light-receiving surface side of the transparent electrode 1. ing.

  The optical waveguide layer 5 travels in the traveling direction of the light L11 so that the incident angle θ of the light L11 incident on the light receiving surface F2 of the semiconductor electrode 2 from the normal direction of the light receiving surface F2 of the semiconductor electrode 2 is 30 to 80 °. It has a function to change. The optical waveguide layer 5 is composed of a plurality of glass fibers 52 having a diameter of about 1 mm plated with Ag. And each glass fiber 52 is arrange | positioned so that it may incline (inclination angle (theta) 5) with respect to the normal line direction of the light-receiving surface F2 of the semiconductor electrode 2, when arrange | positioning on the light-receiving surface F1 of the transparent electrode 1. FIG. At this time, the inclination angle θ5 with respect to the normal direction of the light receiving surface F2 of each glass fiber 52 is adjusted so as to coincide with the incident angle θ of the light L11 incident obliquely on the light receiving surface F2 of the semiconductor electrode 2. The light L11 incident on the optical waveguide layer 5 from the normal direction of the light receiving surface F1 of the transparent electrode 1 is incident on each glass fiber 52 of the optical waveguide layer 5 and its traveling direction is changed at the same time. The incident angle when entering the second light receiving surface F2 is adjusted to be 30 to 80 °. Thereby, this dye-sensitized solar cell 11 can also improve the utilization rate of incident light and the effective energy conversion efficiency similarly to the dye-sensitized solar cell 10 shown in FIG. Each glass fiber 52 constituting the optical waveguide layer 5 is, for example, plated with Ag on the surface by a known method, and then bundled and fixed, and then obliquely cut so as to have the inclination angle described above. Can be produced. The optical waveguide layer 5 may also serve as a protective glass provided on the light receiving surface F1 of the transparent electrode 1. Further, a rare earth element may be added to the optical waveguide layer 5 to impart fluorescence to ultraviolet light. Further, a protective glass (not shown) may be separately provided in addition to the optical waveguide layer 5, and in this case, it is provided on the optical waveguide layer 5 instead of on the light receiving surface F <b> 1 of the transparent electrode 1.

[Third embodiment]
Hereinafter, a third embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 4 is a schematic cross-sectional view showing a third embodiment of the dye-sensitized solar cell of the present invention.

  As shown in FIG. 4, the dye-sensitized solar cell 12 of the present embodiment is a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. And a counter electrode CE and an electrolyte E filled in a gap formed between the photoelectrode WE and the counter electrode CE by a spacer S (not shown).

  The dye-sensitized solar cell 12 includes an optical waveguide layer 5 (light guide means) having a shape different from that of the dye-sensitized solar cell 11 illustrated in FIG. 3 on the light receiving surface side of the transparent electrode 1. Except that the comb-shaped electrode (collecting electrode) 22 provided on the light-receiving surface F2 side of the semiconductor electrode 2 when the single cell of the dye-sensitized solar cell is scaled up to a practical scale, It has the same configuration as the dye-sensitized solar cell 11 shown in FIG.

  As shown in FIG. 4, the optical waveguide layer 5 of the dye-sensitized solar cell 12 has a plurality of grooves (substantially trapezoidal in cross section) arranged in parallel with the light receiving surface F1 side of the transparent electrode 1. A plurality of convex portions 53 whose cross sections formed between the grooves have a substantially triangular prism shape are formed. Each convex portion 53 has a reflection surface F5 that changes the traveling direction of the light traveling in the optical waveguide layer 5.

  The optical waveguide layer 5 is disposed on the transparent electrode 1 so that the tips of the plurality of convex portions 53 are in contact with the light receiving surface F1 of the transparent electrode 1. As a result, a light receiving surface F5 having a predetermined inclination angle with respect to the light receiving surface F1 of the transparent electrode 1 is formed in the optical waveguide layer 5. The reflection surface F5 has an inclination angle of θ4 (> θ3) with respect to the reflection surface R1 formed in the lower partial region where the inclination angle of the transparent electrode 1 with respect to the light reception surface F1 is θ3 and the light reception surface F1 of the transparent electrode 1. The reflecting surface R2 is formed in the upper partial region.

  In the case of the dye-sensitized solar cell 12, a space 6 having a substantially trapezoidal cross section is formed between the optical waveguide layer 5 and the transparent electrode 1 due to the shape of the optical waveguide layer 5. ing. The space 6 is preferably filled with a gas such as a vacuum state or air from the viewpoint of total reflection, but the refractive index may satisfy the condition of 86.6% or less of the refractive index of the optical waveguide layer 5. For example, an organic material or the like may be filled.

  Note that the surface F55 of the optical waveguide layer 5 in which the cross section of the space 6 shown in FIG. 4 corresponds to the upper base portion of the trapezoid is provided for processing reasons, and the area of this portion is preferably as small as possible. Therefore, ideally, the space 6 formed between the optical waveguide layer 5 and the transparent electrode 1 preferably has a substantially triangular cross section.

  Then, as shown in FIG. 4, the light L12 incident from the normal direction of the light receiving surface F1 of the transparent electrode 1 with respect to the reflecting surface F5 of the optical waveguide layer 5 is a reflecting surface formed in the lower partial region. Due to the difference in inclination angle between R1 and the reflecting surface R2 formed in the upper partial region, the incident angle θ is 30 to 80 ° with respect to the light receiving surface F2 of the semiconductor electrode 2 while avoiding the comb-shaped electrode 22. The direction of travel will be adjusted. In this dye-sensitized solar cell 12, the incident angle θ of light incident on the light receiving surface F2 of the semiconductor electrode 2 is not uniform. Therefore, in FIG. 4, an incident angle that is an example of the incident angle θ. θ1 is shown.

  Thus, the dye-sensitized solar cell 12 is caused by the comb-shaped electrode 22 generated in the conventional dye-sensitized solar cell even when the cell is scaled up to a practical scale (for example, 100 × 100 mm). In the same manner as the dye-sensitized solar cell 10 shown in FIG. 1 and the dye-sensitized solar cell 11 shown in FIG. Energy conversion efficiency can be improved.

  The refractive index of the space 6 shown in FIG. 4 is preferably 86.6% or less of the refractive index of the optical waveguide layer 5. Moreover, it is preferable that the refractive index of the transparent electrode 1 is larger than the refractive index of the site | part of the space 6 shown in FIG.

[Fourth embodiment]
Hereinafter, a fourth embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 5 is a schematic cross-sectional view showing a fourth embodiment of the dye-sensitized solar cell of the present invention.

  As shown in FIG. 5, the dye-sensitized solar cell 14 of the present embodiment has a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. And a counter electrode CE and an electrolyte E filled in a gap formed by the spacer S between the photoelectrode WE and the counter electrode CE.

  The dye-sensitized solar cell 14 includes the transparent electrode 1 (light guide means) having a structure different from that of the dye-sensitized solar cell 11 illustrated in FIG. 3 and does not include the optical waveguide layer 5. Except this, it has the same configuration as the dye-sensitized solar cell 11 shown in FIG.

  As shown in FIG. 5, the light guide means of the dye-sensitized solar cell 14 is a plurality of reflecting portions 120 formed in the transparent electrode 1. Each reflecting portion 120 is formed from a reflecting surface F120 that changes the traveling direction of the light L14 traveling in the transparent electrode 1. The inside of each reflecting portion 120 is a space 122 having a substantially triangular cross section. This space 122 is preferably filled with a gas such as a vacuum state or air from the viewpoint of total reflection, but if the refractive index satisfies the condition of 86.6% or less of the refractive index of the transparent electrode 1. For example, an organic material or the like may be filled.

  And the reflective surface F120 of each reflective part 120 is with respect to the normal line direction of the light-receiving surface F2 of the semiconductor electrode 2 so that the incident angle θ of light incident on the light-receiving surface F2 of the semiconductor electrode 2 is 30 to 80 °. And having a predetermined inclination (inclination angle θ120). Thereby, this dye-sensitized solar cell 14 also improves the utilization rate of incident light like the above-mentioned dye-sensitized solar cell 10, dye-sensitized solar cell 11, and dye-sensitized solar cell 12, Effective energy conversion efficiency can be improved. Note that the refractive index of the space 122 shown in FIG. 5 needs to be 86.6% or less of the refractive index of the transparent electrode 1.

[Fifth Embodiment] Hereinafter, a fifth embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 6 is a schematic cross-sectional view showing a fifth embodiment of the dye-sensitized solar cell of the present invention.

  As shown in FIG. 6, the dye-sensitized solar cell 15 of the present embodiment is a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. And a counter electrode CE and an electrolyte E filled in a gap formed by the spacer S between the photoelectrode WE and the counter electrode CE.

  The dye-sensitized solar cell 15 includes the transparent electrode 1 (light guide means) having a structure different from that of the dye-sensitized solar cell 11 illustrated in FIG. 3 and does not include the optical waveguide layer 5. Except this, it has the same configuration as the dye-sensitized solar cell 11 shown in FIG.

  As shown in FIG. 6, the light guide means of the dye-sensitized solar cell 15 is a plurality of convex portions 140 formed on the light receiving surface F <b> 1 of the transparent electrode 1. Each convex portion 140 has a reflective surface F140 that changes the traveling direction of the light L15 incident from the normal direction of the light receiving surface F2 of the semiconductor electrode 2.

  And the reflective surface F140 of each convex part 140 is with respect to the normal line direction of the light-receiving surface F2 of the semiconductor electrode 2 so that the incident angle θ of light incident on the light-receiving surface F2 of the semiconductor electrode 2 is 30 to 80 °. And having a predetermined inclination (inclination angle θ140). Accordingly, the dye-sensitized solar cell 15 is also incident in the same manner as the dye-sensitized solar cell 10, the dye-sensitized solar cell 11, the dye-sensitized solar cell 12, and the dye-sensitized solar cell 14 described above. The utilization factor of light can be improved and the effective energy conversion efficiency can be improved. In the dye-sensitized solar cell 15, the refractive index of the transparent electrode 1 needs to be larger than air and smaller than the semiconductor electrode 2.

[Sixth Embodiment] The sixth embodiment of the dye-sensitized solar cell of the present invention will be described below with reference to FIGS. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 7 is a schematic cross-sectional view showing a fifth embodiment of the dye-sensitized solar cell of the present invention. FIG. 8 is an enlarged view of the region R shown in FIG.

  As shown in FIGS. 7 and 8, the dye-sensitized solar cell 16 of the present embodiment has a semiconductor electrode 2 having a thickness of mainly 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. A photoelectrode WE, a counter electrode CE, and an electrolyte E filled in a gap formed by the spacer S between the photo electrode WE and the counter electrode CE.

  The dye-sensitized solar cell 16 includes the transparent electrode 1 (light guide means) having a structure different from that of the dye-sensitized solar cell 11 illustrated in FIG. 3 and does not include the optical waveguide layer 5. Except this, it has the same configuration as the dye-sensitized solar cell 11 shown in FIG.

As shown in FIGS. 7 and 8, the light guide means of the dye-sensitized solar cell 16 is a plurality of diffraction fringes 160 formed on the light receiving surface F <b> 1 of the transparent electrode 1. The diffraction fringes 160 are made of a transparent material having a refractive index higher than that of the transparent electrode 1 so that the incident angle of light incident on the light receiving surface F2 of the semiconductor electrode 2 is 30 to 80 °. The light L16 incident from the normal direction of the light receiving surface F2 of the semiconductor electrode 2 is diffracted at a predetermined angle. Examples of the transparent substance having a refractive index higher than that of the transparent electrode 1 include Ta ₂ O ₅ . As shown in FIG. 7, in the dye-sensitized solar cell 16, diffracted light other than the 0th-order diffracted light L160 of the light L16 diffracted by each diffraction fringe 160 is incident on the light receiving surface F2 of the semiconductor electrode 2. The incident angle is 30 to 80 °. For example, in FIG. 7, the first-order diffracted light L161 and the second-order diffracted light L162 of the light L16 incident from the normal direction of the light receiving surface F2 of the semiconductor electrode 2 are 30 to 80 ° with respect to the light receiving surface F2 of the semiconductor electrode 2. It shows a state where the light is incident at the incident angles θ161 and θ162 in the range.

  Thereby, this dye-sensitized solar cell 16 is also the above-described dye-sensitized solar cell 10, dye-sensitized solar cell 11, dye-sensitized solar cell 12, dye-sensitized solar cell 14, and dye-sensitized solar cell. Like the solar cell 15, the utilization rate of incident light can be improved and the effective energy conversion efficiency can be improved. In the dye-sensitized solar cell 16, a transparent material that is a constituent material of the diffraction fringes 160 is preferably a material having a refractive index of 2.0 or more.

[Seventh Embodiment] Hereinafter, a seventh embodiment of the dye-sensitized solar cell of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding 1st embodiment mentioned above, and the overlapping description is abbreviate | omitted. FIG. 9 is a schematic cross-sectional view showing a seventh embodiment of the dye-sensitized solar cell of the present invention.

  As shown in FIG. 9, the dye-sensitized solar cell 17 of the present embodiment has a photoelectrode WE having a semiconductor electrode 2 having a thickness of 5 to 30 μm and a transparent electrode 1 disposed on the light receiving surface F2. And a counter electrode CE and an electrolyte E filled in a gap formed by the spacer S between the photoelectrode WE and the counter electrode CE.

  The dye-sensitized solar cell 17 includes the transparent electrode 1 having a shape different from that of the dye-sensitized solar cell 10 shown in FIG. 1, and a practical scale of a single cell of the dye-sensitized solar cell. 1 is the same as the dye-sensitized solar cell 10 shown in FIG. 1 except that the comb-shaped electrode (collecting electrode) 22 provided on the light receiving surface F2 side of the semiconductor electrode 2 is provided. It has a configuration.

  As shown in FIG. 9, the dye-sensitized solar cell 17 is configured so that the incident angle θ of light that travels through the transparent electrode 1 and enters the light receiving surface F2 of the semiconductor electrode 2 is 30 to 80 °. The light receiving surface of the transparent electrode 1 is formed such that the light receiving surface F2 of the semiconductor electrode 2 is formed and light is selectively irradiated to the region of the light receiving surface F2 of the semiconductor electrode 2 where the current collecting electrode 22 is not formed. F1 is formed.

  That is, like the semiconductor electrode 2 of the dye-sensitized solar cell 17 shown in FIG. 1, the semiconductor electrode 2 shown in FIG. 9 is formed so that the shape of the electrode layer when viewed from the cross-sectional direction is a sawtooth shape. Has been. Further, similarly to the transparent electrode 1 of the dye-sensitized solar cell 17 shown in FIG. 1, the contact surface of the transparent electrode 1 shown in FIG. 9 with the semiconductor electrode 2 has a sawtooth shape matching the shape of the semiconductor electrode 2. Grooves are formed. And the light-receiving surface F1 of the transparent electrode 1 shown in FIG. 9 has the convex part 170 of several convex lens shape. The radius of curvature of each convex portion 170 is set so that light is selectively applied to a region of the light receiving surface F2 of the semiconductor electrode 2 where the current collecting electrode 22 is not formed.

  In the case of the dye-sensitized solar cell 17, since the light receiving surface F 1 of the transparent electrode 1 and the light receiving surface F 2 of the semiconductor electrode 2 are not flat, a flat virtual surface inside the transparent electrode 1 or the semiconductor electrode 2. Is provided as a virtual light receiving surface FP1, and the normal direction of the virtual light receiving surface FP1 is set as the traveling direction of light incident from the outside. Designed. In this case, a case where a virtual light receiving surface FP1 is provided inside the transparent electrode 1 is shown.

  Accordingly, the dye-sensitized solar cell 17 is also incident in the same manner as the dye-sensitized solar cell 10, the dye-sensitized solar cell 11, the dye-sensitized solar cell 12, and the dye-sensitized solar cell 14 described above. The utilization factor of light can be improved and the effective energy conversion efficiency can be improved. In the dye-sensitized solar cell 17, the refractive index of the transparent electrode 1 is preferably 1.4 or more.

[Embodiment of dye-sensitized solar cell module]
Hereinafter, a preferred embodiment of the dye-sensitized solar cell module of the present invention will be described with reference to FIGS. 10 and 11. In addition, the same code | symbol is attached | subjected about the element same as the element demonstrated regarding embodiment of the dye-sensitized solar cell of this invention mentioned above, and the overlapping description is abbreviate | omitted. FIG. 10 is a schematic cross-sectional view showing a preferred embodiment of the dye-sensitized solar cell module of the present invention, and FIG. 11 shows the dye sensitization constituting the dye-sensitized solar cell module shown in FIG. It is a schematic cross section of a sensitive solar cell.

  As shown in FIG. 10, the dye-sensitized solar cell module 13 of the present embodiment mainly includes a plurality of dye-sensitized solar cells UC and a base 7 for installing a plurality of dye-sensitized solar cells UC. And a spacer S and a tempered glass plate 9. Further, as shown in FIG. 11, each dye-sensitized solar cell UC has the same structure as the conventional one, and is mainly formed on the semiconductor electrode 2 having a thickness of 5 to 30 μm and its light receiving surface F2. A photoelectrode WE having the transparent electrode 1, a counter electrode CE, and an electrolyte E filled in a gap formed by the spacer S between the photoelectrode WE and the counter electrode CE.

Each dye-sensitized solar cell UC comprises an upper base 7 such that the incident angle of light incident from the normal direction of the installation surface F7 of the base 7 relative to the light receiving surface F _UC theta is 30 to 80 ° Is arranged. Thereby, since the utilization factor of the incident light of each dye-sensitized solar cell UC improves, the effective energy conversion efficiency as the whole module can be improved with respect to the conventional dye-sensitized solar cell module. . Furthermore, in this case, the light reflected on the light receiving surface F2 of the semiconductor electrode 2 of one dye-sensitized solar cell UC is obliquely incident on the light receiving surface F2 of the semiconductor electrode 2 of another dye-sensitized solar cell UC. Therefore, it is possible to obtain a large antireflection effect as a whole module.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the above embodiment.

  For example, in the dye-sensitized solar cell and the dye-sensitized solar cell module of the above-described embodiment of the present invention, the case where sunlight is used as the light source has been described, but the dye-sensitized solar cell and the dye of the present invention are described. The sensitized solar cell module is not limited to this. For example, ultraviolet light may be used as the light source. In this case, an additive that enhances fluorescence with respect to ultraviolet light may be added to the semiconductor electrode or the like. For example, in the dye-sensitized solar cell 11 of Example 2, a treatment such as addition of a rare earth element in the optical waveguide layer 5 may be performed.

Hereinafter, the dye-sensitized solar cell and the dye-sensitized solar cell module of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In addition, about the component of the dye-sensitized solar cell and dye-sensitized solar cell module of a following example and a comparative example, the same code | symbol is attached | subjected and demonstrated to the part which is the same as that of the above-mentioned embodiment.

In addition, in the dye-sensitized solar cells of the following examples and comparative examples, the optical waveguide layer 5 (light guide means) shown in FIG. 3 is provided, and the semiconductor electrode 2 is provided. As described above, “effective energy conversion efficiency” indicates energy conversion efficiency per S ₀ instead of S ₀ cos θ. Therefore, “−” is written in the column of S ₀ cos θ in Table 1.

Example 1
A 50 × 50 mm scale dye-sensitized solar cell having the same configuration as the dye-sensitized solar cell 10 shown in FIG. 1 was prepared as described below.

First, a glass substrate having a sawtooth surface similar to the shape of the sawtooth portion of the layer of the semiconductor electrode 2 was produced as the substrate 4 of the transparent electrode 1 by casting. Next, this glass substrate was spray-coated with fluorine-doped SnO ₂ as a transparent conductive film 3 so as to have a film thickness of 800 nm, and further, heat treatment was performed under conditions of 500 ° C.

Then, the actual area of the relative serrated surface of the transparent electrode 1, the TiO ₂ from the direction described in the explanation of the dye-sensitized solar cell 10 was deposited by electron beam evaporation method above, the light receiving surface F2 140 × 48 mm, layer thickness: 7 μm, length of one side of the sawtooth portion of the layer; 5 mm, inclination angle θs of the sawtooth portion; 70 ° (incident angle θ of light to the light receiving surface F2; 70 °) Was made. As the vapor deposition apparatus, an EBV-6D type high vacuum vapor deposition apparatus manufactured by Nippon Vacuum Technology Co., Ltd. was used. As the evaporation source, a high-purity Pure Chemical Research Laboratory of TiO ₂ (rutile, purity: 99.99%) was used. Deposition conditions are as follows: effective size of vapor deposition surface; 47.9 × 48.0 mm, vapor deposition rate; 1.4 nm / s, substrate temperature; 205 ° C., degree of vacuum in vapor deposition apparatus container before vapor deposition; 1 × 10 ⁻³ Pa, degree of vacuum in the container of the vapor deposition apparatus during vapor deposition; 1 × 10 ⁻³ Pa.

Next, the temperature in the container of the vapor deposition apparatus is increased from 60 ° C. to 400 ° C. at a temperature increase rate of 10 ° C./min, held at this temperature for 30 minutes, and TiO ₂ deposited on the transparent electrode 1. The semiconductor electrode 2 was annealed. As a result, the amorphous phase of TiO _{2 formed} on the transparent electrode 1 was crystallized into an anatase phase. It was confirmed in advance by X-ray diffraction that the amorphous phase of the formed TiO ₂ crystallized into the anatase phase by the above-described annealing treatment.

Next, the dye was adsorbed on the surface of the TiO ₂ semiconductor electrode 2 produced as follows. First, anhydrous ethanol dehydrated with magnesium ethoxide is used as a solvent, and a ruthenium complex [cis-Di (thiocyanato) -N, N'-bis (2,2'-bipyridyl-4,4'dicboxylic acid) -ruthenium (II the)], the concentration of dissolved so that 2.85 × ¹⁰ -4 mol / L, to prepare a ruthenium complex solution. Next, the semiconductor electrode 2 was immersed in this solution for 24 hours. Thereby, about 1.0 * 10 < ^-7 > mol / cm < ² > adsorption | suction of the ruthenium complex used as a pigment | dye on the semiconductor electrode 2 was carried out. Next, in order to improve the open circuit voltage Voc, the semiconductor electrode 2 after adsorption of the ruthenium complex was immersed in an acetonitrile solution for 15 minutes, and then dried in a nitrogen stream maintained at 25 ° C., thereby completing the photoelectrode WE.

On the other hand, the counter electrode CE was an electrode obtained by depositing a Pt thin film (film thickness: 3 nm) on a fluorine-doped SnO ₂ coated glass substrate having the same shape and size as the transparent electrode 1. In addition, as the electrolyte E, a mixed solution of ethylene carbonate; 21.14 g and acetonitrile; 4.0 mL was added to tetra-n-propylammonium iodide (Tetra-n-propylammonium iodide); 3.13 g and iodine; 0 An iodine redox solution in which 18 g was dissolved was prepared. Furthermore, a DuPont spacer S (trade name: “HIMILAN”) having a shape corresponding to the size of the semiconductor electrode 2 is prepared, and the photoelectrode WE, the counter electrode CE, and the spacer S are interposed as shown in FIG. The dye-sensitized solar cell was completed by filling the above electrolyte E inside.

(Example 2)
Example 1 A dye-sensitized solar cell similar to Example 1 except that the semiconductor electrode 2 having an inclination angle θs of the sawtooth portion: 45 ° (incident angle θ of light to the light receiving surface F2; 45 °) was produced. It was produced by the same production method.

(Example 3)
Example 1 A dye-sensitized solar cell similar to Example 1 except that the semiconductor electrode 2 having an inclination angle θs of the sawtooth portion: 30 ° (incident angle θ of light to the light receiving surface F2; 30 °) was produced. It was produced by the same production method.

(Comparative Example 1)
Except that the shape of the photoelectrode WE and the counter electrode CE is the same as that of the conventional dye-sensitized solar cell shown in FIG. 11 (incident angle θ of light to the light receiving surface F2; 0 °), it is the same as in the first embodiment. A dye-sensitized solar cell was produced by the same production method as in Example 1.

(Comparative Example 2)
Example 1 A dye-sensitized solar cell similar to Example 1 except that the semiconductor electrode 2 having a sawtooth inclination angle θs of 20 ° (light incident angle θ on the light receiving surface F2; 20 °) was produced. It was produced by the same production method.

Example 4
A dye-sensitized solar cell having the configuration shown in FIG. 3 and the same size as in Example 1 (actual area S ₀ of light-receiving surface F2; 48 × 48 mm, layer thickness: 7 μm) was produced. This dye-sensitized solar cell has an optical waveguide layer 5 (inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1; 70 °, incident angle θ of light on the light receiving surface F2) provided on the light receiving surface F1 of the transparent electrode 1. ; Except for 70 °), the shapes of the photoelectrode WE and the counter electrode CE are the same as those of the conventional dye-sensitized solar cell shown in FIG.

  As the plurality of glass fibers constituting the optical waveguide layer 5, glass fibers having a diameter of 1 mm were used. The surface of this glass fiber was plated with Ag, and bundled and fixed, and then obliquely cut in accordance with the above inclination angle θ to have a length of 5 mm. A plurality of glass fibers thus produced were arranged on the light receiving surface of the transparent electrode 1 with a glass adhesive.

(Example 5)
The same dye-sensitized type as in Example 4 except that the optical waveguide layer 5 having an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1 of 45 ° and an incident angle θ of light with respect to the light receiving surface F2 of 45 ° was prepared. A solar cell was produced by the same production method as in Example 4.

(Example 6)
The same dye-sensitized type as in Example 4 except that the optical waveguide layer 5 was manufactured with an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1 of 30 ° and an incident angle θ of light with respect to the light receiving surface F2 of 30 °. A solar cell was produced by the same production method as in Example 4.

(Example 7)
A dye-sensitized solar cell having the same configuration as in Example 4 except that 0.2 mol% of rare earth element (samarium) is added to the optical waveguide layer 5 to improve the fluorescence with respect to ultraviolet light. The same production method was used.

(Comparative Example 3)
Comparative Example 1 is the same as Comparative Example 1 except that 0.2 mol% of a rare earth element (samarium) is added in the vicinity of the light-receiving surface F1 of the transparent electrode 1 of the dye-sensitized solar cell of Comparative Example 1 to improve the fluorescence with respect to ultraviolet light. A dye-sensitized solar cell having the following structure was produced by the same production method as in Example 1.

(Example 8)
Screen printing of commercially available TiO ₂ particles (average particle size; 30 nm) and paste prepared for screen printing using a screen printer, followed by heat treatment for 30 minutes under a temperature condition of 400 ° C. Accordingly, thickness of 20μm on the transparent electrode 1, the actual area S ₀ of the light-receiving _surface; a except for using the semiconductor electrode 73.47Mm ^2, dye-sensitized solar cell having the same structure as in example 4 Produced.

Example 9
Screen printing of commercially available TiO ₂ particles (average particle size; 30 nm) and paste prepared for screen printing using a screen printer, followed by heat treatment for 30 minutes under a temperature condition of 400 ° C. Thus, a dye-sensitized solar cell having the same configuration as that of Example 5 except that a semiconductor electrode having a film thickness of 20 μm and an actual area S ₀ of the light receiving surface of 73.47 mm ² was used on the transparent electrode 1. Produced.

(Example 10)
Screen printing of commercially available TiO ₂ particles (average particle size; 30 nm) and paste prepared for screen printing using a screen printer, followed by heat treatment for 30 minutes under a temperature condition of 400 ° C. Thus, a dye-sensitized solar cell having the same configuration as in Example 6 except that a semiconductor electrode having a film thickness of 20 μm and an actual area S ₀ of the light receiving surface of 73.47 mm ² is used on the transparent electrode 1. Produced.

(Comparative Example 4)
The same dye-sensitized type as in Example 8 except that the optical waveguide layer 5 was formed with an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1 of 0 ° and an incident angle θ of light with respect to the light receiving surface F2 of 0 °. A solar cell was produced by the same production method as in Example 8.

(Comparative Example 5)
The same dye-sensitized type as in Example 9 except that the optical waveguide layer 5 was formed with an inclination angle θ5 of the transparent electrode 1 with respect to the light receiving surface F1 of 20 ° and an incident angle θ of light to the light receiving surface F2 of 20 °. A solar cell was produced by the same production method as in Example 9.

(Comparative Example 6)
The same dye-sensitized type as in Example 10 except that the optical waveguide layer 5 having an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1; 85 ° and an incident angle θ of light with respect to the light receiving surface F2; A solar cell was produced by the same production method as in Example 10.

Example 11
By tape-casting two types of commercially available TiO ₂ particles (average particle size: 200 nm, 25 nm), a semiconductor electrode having a film thickness of 10 μm and an actual area S ₀ of the light receiving surface of 71.1 mm ² is formed on the transparent electrode 1. A dye-sensitized solar cell having the same configuration as in Example 4 was produced by the same production method as in Example 4 except that it was used.

Incidentally, the tape-casting of the above TiO ₂ particles was performed according to the following procedure. That is, first, the powder of TiO ₂ particles was kneaded in an alumina mortar together with ion-exchanged water and a chelating agent. Next, ion-exchanged water and a surfactant were added to an alumina mortar and mixed by stirring to prepare a slurry containing TiO ₂ particles. Next, a scotch tape was applied on the transparent electrode 1 with an interval of 10 mm. Next, the slurry was dropped into the groove formed between the tapes. Next, by extending using a glass rod, the dropped slurry was developed over the entire groove formed between the tapes. Next, after this slurry was dried at room temperature for about 1 day, the scotch tape on the transparent electrode 1 was removed. Next, the slurry was heat-treated in an air stream at 450 ° C. for 30 minutes.

Example 12
Two types of TiO ₂ particles (average particle size; 220 nm, 30 nm) synthesized by the autoclave method are tape-cast in the same manner as in Example 11 so that the film thickness is 10 μm on the transparent electrode 1 and the actual area S of the light receiving surface. ₀ : A dye-sensitized solar cell having the same configuration as in Example 5 was produced by the same production method as in Example 5 except that a semiconductor electrode of 71.1 mm ² was used.

(Example 13)
Two types of TiO ₂ particles (average particle size; 220 nm, 30 nm) synthesized by the autoclave method are tape-cast in the same manner as in Example 11 so that the film thickness is 10 μm on the transparent electrode 1 and the actual area S of the light receiving surface. ₀ : A dye-sensitized solar cell having the same configuration as in Example 6 was produced by the same production method as in Example 6 except that a semiconductor electrode of 71.1 mm ² was used.

(Comparative Example 7)
The same dye-sensitized type as in Example 11 except that the optical waveguide layer 5 was formed with an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1 of 0 ° and an incident angle θ of light with respect to the light receiving surface F2 of 0 °. A solar cell was produced by the same production method as in Example 11.

(Comparative Example 8)
The same dye-sensitized type as in Example 12 except that the optical waveguide layer 5 was formed with an inclination angle θ5 of the transparent electrode 1 with respect to the light receiving surface F1 of 20 ° and an incident angle θ of light to the light receiving surface F2 of 20 °. A solar cell was produced by the same production method as in Example 12.

(Comparative Example 9)
The same dye-sensitized type as in Example 13 except that the optical waveguide layer 5 having an inclination angle θ5 with respect to the light receiving surface F1 of the transparent electrode 1 of 85 ° and an incident angle θ of light with respect to the light receiving surface F2 of 85 ° was prepared. A solar cell was produced by the same production method as in Example 13.

(Example 14)
A dye-sensitized solar cell module having the configuration shown in FIG. 10 was produced. This dye-sensitized solar cell module has the configuration shown in FIG. 11 and has the same size as that of the dye-sensitized solar cell of Example 1, the dye-sensitized solar cell UC (of the light receiving surface F2). Actual area: 48 × 48 mm, layer thickness: 7 μm, manufactured using 290 light incident angles of 70 ° to each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 did.

Each dye-sensitized solar cell UC was arranged on the base 7 so that there were 29 pieces in the left-right direction and 10 pieces in the depth direction when viewed from the front of FIG. Further, a spacer S made of Teflon (registered trademark) is arranged on the outer edge of the base 7, and each dye-sensitized type is disposed on the light-receiving surface side of each dye-sensitized solar cell UC arranged on the base 7. A tempered glass plate 9 made by Asahi Glass Co., which covers the entire solar cell UC was disposed.

(Example 15)
A dye-sensitized solar cell module having the same configuration as in Example 14 except that the incident angle of light incident on each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 is 45 °. Was made.

(Example 16)
A dye-sensitized solar cell module having the same configuration as in Example 14 except that the incident angle of light incident on each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 is set to 30 °. Was made.

(Comparative Example 10)
A dye-sensitized solar cell module having the same configuration as in Example 14 except that the incident angle of light incident on each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 is set to 0 °. That is, a dye-sensitized solar cell module having a conventional structure was produced.

(Comparative Example 11)
A dye-sensitized solar cell module having the same configuration as in Example 14 except that the incident angle of light incident on each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 is set to 20 °. Was made.

(Comparative Example 12)
A dye-sensitized solar cell module having the same configuration as in Example 14 except that the incident angle of light incident on each dye-sensitized solar cell UC from the normal direction of the installation surface F7 of the base 7 is set to 85 °. Was made.

[Battery characteristics test]
Effective energy conversion efficiencies η of the modules of the dye-sensitized solar cells and the dye-sensitized solar cells of Examples 1 to 16 and Comparative Examples 1 to 12 were measured. The battery characteristic test was performed using a large solar simulator calibrated using a solar simulator (WXS-85 manufactured by Wacom Denso Co., Ltd.), irradiating 1000 W / m ² of pseudo-sunlight, and using an IV tester. Voltage characteristics were measured to determine the open circuit voltage, short circuit current, and effective energy conversion efficiency. The results are shown in Table 1.

  As is clear from the results shown in Table 1, the effective energy conversion efficiencies η of the modules of the dye-sensitized solar cells and the dye-sensitized solar cells of Examples 1 to 16 are the corresponding comparisons. The values higher than the effective energy conversion efficiency η of the modules of the dye-sensitized solar cell and the dye-sensitized solar cell of Example 1 to Comparative Example 12 were shown. For example, compared to the energy conversion efficiency of the dye-sensitized solar cell of Comparative Example 1, the energy conversion efficiency of the dye-sensitized solar cell of Example 1 is improved by 25%, and the dye-sensitized solar cell of Example 5 is improved. The energy conversion efficiency of the battery was improved by 20%.

  Furthermore, compared with the effective energy conversion efficiency η of the dye-sensitized solar cell module of Comparative Example 10, the effective energy conversion efficiency η of the dye-sensitized solar cell of Example 15 is improved by 20%. The energy conversion efficiency of the dye-sensitized solar cell of Example 14 was improved by 25%.

  As is clear from these results, it was confirmed that the dye-sensitized solar cell and the dye-sensitized solar cell module of the present invention are extremely effective in improving the energy conversion efficiency of the solar cell. The absolute value of the energy conversion efficiency of the dye-sensitized solar cell varies depending on the composition of the electrolytic solution and the type of the dye, independently of the configuration of the present invention. The current energy conversion efficiency can be improved. That is, according to the dye-sensitized solar cell and the dye-sensitized solar cell module of the present invention, a universal energy conversion efficiency improvement effect can be obtained.

(Example 17)
A dye-sensitized 100 × 100 mm scale having the same configuration as that of the dye-sensitized solar cell 12 shown in FIG. 4 except that the optical waveguide layer 5a having the shape shown in FIGS. 12 (a) to 12 (c) is provided. A solar cell (actual area S ₀ of the light receiving surface F2; 96 × 96 mm, thickness: 22 mm) was produced by the same procedure as in Example 1.

  12A is another cross-sectional view of the optical waveguide layer 5a provided in this dye-sensitized solar cell, and FIG. 12B shows the optical waveguide layer 5a shown in FIG. 12A as a photoelectrode. FIG. 12C is a front view when viewed from the WE side, and FIG. 12C is an enlarged view of the partial region PR1 of the optical waveguide layer 5a shown in FIG.

  In the optical waveguide layer 5a (width W5a; 100 mm, depth Y; 100 mm, thickness; 4 mm) shown in FIGS. 12 (a) to 12 (c), a predetermined distance with respect to the light receiving surface F1 of the transparent electrode 1 is set as described above. In this case, the inclination angle θ3 with respect to the light receiving surface F1 of the transparent electrode 1 is 59 ° ± 0.5 °, and the reflection surface R1 and the transparent electrode formed in the lower partial region are formed. The inclination angle θ4 with respect to the light receiving surface F1 is 63 ° ± 0.5 °.

  In this optical waveguide layer 5a, the glass (transparent electrode 1) constituting the dye-sensitized solar cell has a thickness of 1.1 mm, a refractive index of 1.52, and a comb-shaped electrode 22 having a width of 0.5 mm. In contrast to the configuration in which the distance between the comb-shaped electrodes 22 is 12 mm, the light-shielding loss due to the comb-shaped electrodes 22 is designed so as not to occur.

  FIG. 13 is a cross-sectional view of the optical waveguide layer 5a. FIG. 13 (a) shows the result of ray tracing when normal incident light is incident on the optical waveguide layer 5a. FIG. 13B is an enlarged view of the partial region PR2 of the coat layer shown in FIG. Further, when the effective energy conversion efficiency of the dye-sensitized solar cell was determined in the same manner as the battery characteristic test described above, it was 6.2%.

(Comparative Example 13)
A conventional dye-sensitized solar cell having the same configuration as that of the dye-sensitized solar cell of Example 17 except that the optical waveguide layer 5a shown in FIG. 12 is not provided is manufactured, and its energy conversion efficiency Was 5.1%.

It is a schematic cross section which shows 1st embodiment of the dye-sensitized solar cell of this invention. It is process drawing which shows an example of the manufacturing process of the photoelectrode of the dye-sensitized solar cell of FIG. It is a schematic cross section which shows 2nd embodiment of the dye-sensitized solar cell of this invention. It is a schematic cross section which shows 3rd embodiment of the dye-sensitized solar cell of this invention. It is a schematic cross section which shows 4th embodiment of the dye-sensitized solar cell of this invention. It is a schematic cross section which shows 5th embodiment of the dye-sensitized solar cell of this invention. It is a schematic cross section which shows 6th embodiment of the dye-sensitized solar cell of this invention. It is a model expanded sectional view of the part of the area | region R shown in FIG. It is a schematic cross section which shows 7th embodiment of the dye-sensitized solar cell of this invention. It is a schematic cross section which shows suitable one Embodiment of the dye-sensitized solar cell module of this invention. It is a schematic cross section of the dye-sensitized solar cell which comprises the dye-sensitized solar cell module shown in FIG. (A) is sectional drawing which shows another embodiment of the coating layer with which the dye-sensitized solar cell shown in FIG. 4 is equipped, (b) saw the coating layer shown to (a) from the photoelectrode side. It is a front view in the case, (c) is an enlarged view of a partial region PR1 of the coat layer shown in (a). (A) is sectional drawing which shows the ray tracing result at the time of making normal incident light inject into the coating layer shown in FIG. 12, (b) is an enlarged view of the partial area | region PR2 of the coating layer shown to (a). . It is a graph which shows the light incident angle dependence of the energy conversion efficiency of a dye-sensitized solar cell. (A) is a graph showing current-voltage characteristics and energy conversion efficiency when light is incident at an incident angle of about 45 ° with respect to the normal direction of the electrode surface of the dye-sensitized solar cell shown in FIG. FIG. 14B is a graph showing current-voltage characteristics and energy conversion efficiency when incident from the normal direction of the electrode surface of the dye-sensitized solar cell shown in FIG. 14.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Transparent electrode, 2 ... Semiconductor electrode, 3 ... Transparent electrically conductive film, 4 ... Board | substrate, 5 ... Coat layer, 6 ... Space, 7 ... Base, 9 ... Tempered glass board 10, 11, 12, 14, 15, 16, 17 ... Dye-sensitized solar cell, 13 ... Dye-sensitized solar cell module, 22 ... Comb electrode (collecting electrode), 52 ... Glass fiber, 53 ... Projection, 100 ... Dye-sensitized solar cell, DESCRIPTION OF SYMBOLS 120 ... Reflection part, 122 ... Space, 140 ... Convex part, 160 ... Diffraction fringe, 170 ... Convex part, CE ... Counter electrode, E ... Electrolyte, F1, F2, F3 ... Light-receiving surface, F5, F5a ... Reflection surface, F7 ... installation surface, F _{UC ...} light-receiving surface, the surface of the F55 ... optical waveguide layer 5, F 120, F 140 ... reflecting surface, FP1 ... virtual light receiving surface, L10, L11, L12, L14 , L15, L16, L17 ... light, L161, L162 ... diffracted light, PR1, PR2 ... of optical waveguide layer 5a Dividing region, R1, R2 ... Reflecting surface formed in partial region of reflecting surface F5 or F5a, S ... Spacer, UC ... Dye-sensitized solar cell, WE ... Photoelectrode, θ, θ1, θ161, θ162 ... Incident angle , Θ3, θ4, θ120, θ140.

Claims (1)

A dye-sensitized solar cell having a semiconductor electrode and a photoelectrode having a transparent electrode disposed on a light receiving surface thereof, and a counter electrode, wherein the semiconductor electrode and the counter electrode are disposed to face each other with an electrolyte interposed therebetween. There,
The light-receiving surface of the semiconductor electrode is formed such that an incident angle of light incident on the light-receiving surface of the semiconductor electrode from the normal direction of the light-receiving surface of the transparent electrode is 30 to 80 °;
The dye-sensitized solar cell, wherein the light receiving surface of the semiconductor electrode is an interface between the transparent electrode and the semiconductor electrode.

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