JP2012023089A - Power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation device which is capable of generating power while suppressing reduction in transmittance of light entering from a specific direction.SOLUTION: A power-generating window glass 1 comprises: a transparent substrate 10 having a light incident surface S1 and a light emission surface S2 on the opposite sides thereof; a light control film 12 which is provided on the light incident surface S1 of the transparent substrate 10; and a solar cell 11 which is disposed at an end section D of the transparent substrate 10. In the light control film 12, light scattering occurs only when light enters at a predetermined angle, and a part of the scattered light propagates inside the substrate and is received by the solar cell 11 disposed at the end section D. On the other hand, when light enters the light control film 12 at a specific angle different from the predetermined angle, scattering does not occur, and the incident light passes through the light control film 12 and the transparent substrate 10, and is emitted from the light emission surface S2.

Description

  The present invention relates to a power generation apparatus that generates power using, for example, sunlight.

  In recent years, solar cells are being put into practical use in various applications as power generation devices (photoelectric conversion devices) that can realize resource saving and cost reduction. For example, silicon solar cells have been developed using various materials such as silicon thin films, inorganic compounds such as CdTe and ClGS, and organic compounds such as high molecular polymers and low molecular polymers.

  In general, the solar cell as described above has a structure in which a transparent electrode, a photoelectric conversion layer, and a reflective electrode are provided in this order on a transparent substrate such as glass. In such a structure, light incident on the photoelectric conversion layer from the transparent substrate side can be extracted outside as a photocurrent through the transparent electrode and the reflective electrode. As described above, in the solar cell, light energy such as sunlight taken in is converted into electric energy to generate electric power.

  Recently, a technique for adding such a power generation function to, for example, a window glass of a building has been developed (for example, Patent Document 1). In such a power generation device (hereinafter referred to as power generation window glass), a photoelectric conversion layer and a pair of transparent electrodes sandwiching the photoelectric conversion layer are provided on a transparent substrate such as glass, and an adhesive layer is further formed thereon. It has a laminated structure in which another transparent substrate is bonded to each other. Thereby, the sunlight which injects into a window glass is taken in into a photoelectric converting layer, and it has a mechanism by which electric power generation is made | formed.

JP 2006-173412 A

  However, in the power generation window glass as described above, since the photoelectric conversion layer is provided over almost the entire area of the window glass, most of the incident light to the window glass is taken into the photoelectric conversion layer, and the light transmittance of the window glass There is a problem that the remarkably decreases. As a result, the light from the outside (outdoors) is blocked, and the visibility of the outside world has been impaired.

  This invention is made | formed in view of this problem, The objective is to provide the electric power generating apparatus which can generate electric power, suppressing the transmittance | permeability reduction with respect to the incident light from a specific direction.

  The power generation device of the present invention includes a base body having a light incident surface and a light output surface that face each other, a light control layer that is provided on the light incident surface side of the base body, and has a function of varying scattering characteristics depending on an incident angle, And a photoelectric conversion element that receives part of the light emitted from the control layer.

  In the power generation device of the present invention, a light control layer having a function (scattering anisotropy) having different scattering characteristics depending on the incident angle is provided on the light incident surface of the substrate. Scattering occurs only when light is incident at an angle of. A part of the light emitted from the light control layer as scattered light propagates through the inside of the substrate and is then received by the photoelectric conversion element. On the other hand, when light enters the light control layer at a specific angle different from the above, scattering does not occur, and the incident light passes through the light control layer and the substrate and is emitted from the light exit surface.

  According to the power generation device of the present invention, since the light control layer having the function of different scattering characteristics depending on the incident angle is provided on the light incident surface side of the substrate, a part of the light incident at a predetermined angle is photoelectrically converted. While power is generated by being guided to the element, light incident at a specific angle different from that can be transmitted without being scattered and emitted from the light exit surface of the substrate. Therefore, power generation can be performed while suppressing a reduction in transmittance with respect to incident light from a specific direction.

It is sectional drawing showing schematic structure of the electric power generation window glass which concerns on one embodiment of this invention. It is sectional drawing showing the structural example of the solar cell shown in FIG. It is a cross-sectional schematic diagram for demonstrating the (A) function of the light control film shown in FIG. 1, and (B) The cross-sectional schematic diagram showing the structural example. It is a cross-sectional schematic diagram for demonstrating the effect | action of the power generation window glass which concerns on a prior art example. It is a cross-sectional schematic diagram for demonstrating the effect | action of the power generation window glass shown in FIG. 1, (A) is light transmission (no scattering), (B) shows the mode of the light guide to the solar cell by scattering. It is a schematic diagram for demonstrating the illumination intensity measuring method of Comparative Examples 1 and 2 and an Example. It is a characteristic view which shows the illuminance measurement result of Comparative Examples 1 and 2 and an Example. It is a schematic diagram for demonstrating the measuring method of the current-voltage characteristic of the comparative example 2 and an Example. It is a characteristic view which shows the measurement result of the current-voltage characteristic of the comparative example 2 and an Example. It is explanatory drawing about the incident angle and outgoing angle in measurement (simulation). It is a characteristic view which shows the measurement result of the angle of the emitted light with respect to incident light, and the transmittance | permeability. It is a cross-sectional schematic diagram showing the structure of the electric power generation window glass which concerns on the modification 1. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a power generation window glass according to Modification Example 2. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a power generation glass according to Modification 3. FIG.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the invention will be described in detail with reference to the drawings. The description will be given in the following order.

1. Embodiment (Example of power generation window glass in which a light control film is provided on a light incident surface of a transparent substrate and a solar cell is provided on a side surface)
2. Modification 1 (Example in which a solar cell is provided at the end of the light emission surface of the transparent substrate)
3. Modification 2 (Example in which a solar cell is provided at the end of the light incident surface of the transparent substrate)

<Embodiment>
[Configuration of power generation window glass 1]
FIG. 1 shows a cross-sectional configuration of a power generation window glass 1 (power generation device) according to an embodiment of the present invention. The power generation window glass 1 is obtained by adding a power generation function to a transparent substrate such as glass, and is used, for example, as a window glass of a building such as an office building or a house, or a single-walled wall surface. In the present embodiment, the power generation window glass 1 that is installed and used on a side wall of a room will be described as an example. This power generation window glass 1 is used with a predetermined end (end D) facing down (installed on a side wall or the like). The end portion D corresponds to, for example, the side surface of the power generation window glass 1 (transparent substrate 10 described later) and its peripheral portion (near the end portion).

  The power generation window glass 1 is, for example, one in which a light control film 12 (light control layer) as an anisotropic scattering film is bonded to one surface (light incident surface) of a transparent substrate 10 (base), and is transparent. A solar cell 11 is provided at the end of the substrate 10. Among these, the transparent substrate 10 is installed so as to face indoor (indoor) A, and the light control film 12 faces outdoor (outdoor) B, respectively. The solar cell 11 is provided on an end portion D of the transparent substrate 10, for example, on the lower side surface that does not face each of the light incident surface S 1 and the light emitting surface S 2 of the transparent substrate 10 in the present embodiment. The solar cell 11 may be provided over the entire side surface of the transparent substrate 10 and the light control film 12, or may be provided on a part of the side surface of the transparent substrate 10. Moreover, although the solar cell 11 may be exposed with respect to sunlight, it may be covered with the window frame (sash) etc., and may be embed | buried under the floor etc. of a building. Moreover, when the planar shape (surface parallel to the light incident surface) of the transparent substrate 10 is, for example, a rectangular shape, the solar cell 11 may be provided only on one side of the planar shape, or on each side. It may be provided.

(Transparent substrate 10)
The transparent substrate 10 is, for example, a parallel plate-like glass substrate in which the light incident surface S1 and the light emitting surface S2 face each other, and has a thickness of, for example, 0.1 mm to 5.0 mm. However, the transparent substrate 10 may be a plastic substrate such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polycarbonate (PC), COP (cycloolefin polymer), etc., in addition to the glass substrate. Good. Further, the transparent substrate 10 does not necessarily have a parallel plate shape. If the light incident surface S1 and the light emitting surface S2 are opposed to each other, the thickness of the transparent substrate 10 such as a wedge shape is increased between the upper end side and the lower end (end). It may be different on the part D) side.

(Solar cell 11)
The solar cell 11 is a photoelectric conversion element that receives light such as sunlight and converts the energy of the received light into electric power. Examples of the solar cell 11 include those using a silicon thin film, those using crystalline silicon, polycrystalline silicon, and microcrystalline silicon, those using an inorganic compound of III-V group, CdTe, and ClGS, conductive There are various types of solar cells, such as those using organic compounds such as conductive polymers and fullerenes, and those using organic dyes (dye sensitized type). Here, the structure of the organic thin-film solar cell using an organic compound is demonstrated as the example.

  FIG. 2 shows a cross-sectional configuration of a solar cell 11 as an organic thin film solar cell. In the solar cell 11, for example, a transparent electrode 111, a photoelectric conversion layer 112, a LiF (lithium fluoride) layer 113 and a reflective electrode 114 are laminated in this order on a transparent substrate 110. Light is incident from the back side of the transparent substrate 110 and is taken into the photoelectric conversion layer 112.

  The transparent substrate 110 is made of a material that is transparent to light incident on the photoelectric conversion layer 112, such as glass or plastic. The transmittance of the transparent substrate 110 is preferably about 70% or more with respect to the light incident on the photoelectric conversion layer 112. Examples of the plastic that can be suitably used for the transparent substrate 110 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, polycarbonate (PC), and COP (cycloolefin polymer). The transparent substrate 110 is preferably a rigid substrate, but may be a flexible substrate.

  The transparent electrode 111 is made of a material that is transparent to light received by the photoelectric conversion layer 112 and has conductivity. Examples of such materials include ITO (Indium Tin Oxide), SnO (tin oxide), IZO (indium zinc oxide), and the like.

The photoelectric conversion layer 112 has a function of absorbing incident light and converting the energy of the absorbed light into electric power. The photoelectric conversion layer 112 is formed by stacking p-type and n-type conductive polymers that form a pn junction. For example, the photoelectric conversion layer 112 includes, in order from the transparent electrode 111 side, CuPc (copper phthalocyanine) 112a as a p-type conductive film, C ₆₀ (fullerene) 112b as an n-type conductive film, and BCP (Bathocuproine) 112c. Are laminated.

  The LiF layer 113 is made of an alkali metal compound having a small work function and has a function of reducing the drive voltage.

  The reflective electrode 114 is a material that reflects light incident on the photoelectric conversion layer 112 with a high reflectance, such as aluminum (Al), silver (Ag), platinum (Pt), gold (Au), chromium (Cr), It is configured to include at least one of tungsten (W) and nickel (Ni).

(Light control film 12)
3A schematically shows the function of the light control film 12, and FIG. 3B schematically shows a specific structure for realizing such a function. It is. As shown in FIG. 3 (A), the light control film 12 causes scattering when light is incident at a predetermined incident angle (for example, an angle in the scattering region SA), while other specific incidents. When light is incident at an angle (for example, an angle in the non-scattering region SB), it has a function of transmitting light to the transparent substrate 10 side without causing scattering. The scattering region SA corresponds to a specific example of the first angular region in the present invention, and the non-scattering region SB corresponds to a specific example of the second angular region in the present invention.

  The scattering region SA is desirably an angle region corresponding to incident light from obliquely above when the power generation window glass 1 is installed, for example. Specifically, when the direction perpendicular to the light incident surface S1 is 0 °, the upper end side in the axial direction along the light incident surface S1 is 90 °, and the lower end (end D) side is −90 °, for example, 0 It is desirable to set within the range of ° to 90 °, and it is more desirable to set within the range of 30 ° to 90 °. This is because light from the sun can be taken in efficiently.

  The non-scattering region SB is set in an angle region other than the scattering region SA, but preferably includes 0 °. Although details will be described later, this is for ensuring good visibility in the front direction.

  Each of the scattering region SA and the non-scattering region SB is a continuous range (for example, the scattering region SA is 60 ° or more and 90 ° or less, etc.) within the range of −90 ° to 90 °. It may be a discontinuous range or value (for example, the scattering region SA is 50 °, 60 °, 70 °, etc.).

  As a structure exhibiting such scattering anisotropy, for example, a layer structure as shown in FIG. Specifically, the light control film 12 includes first refractive index regions 12A having a refractive index n1 and second refractive index regions 12B having a refractive index n2 alternately and along a predetermined direction α (predetermined Laminated (at an inclination angle). By appropriately adjusting the values of the refractive indexes n1 and n2, the film thickness, the pitch, the inclination angle in the direction α, and the like of the first refractive index region 12A and the second refractive index region 12B, the desired scattering region SA and the non-scattering region. The area SB can be set.

[Operation and effect of power generation window glass 1]
Next, the operation and effect of the power generation window glass 1 as described above will be described with reference to FIGS. FIG. 4 schematically shows a cross-sectional structure of a conventional power generation window glass (power generation window glass 100). FIG. 5A schematically shows the state of light guide to the solar cell 11 when scattering occurs in the light control film 12, and FIG. 5B schematically shows the state of light transmission when non-scattering. Is.

  In the power generation window glass 1, a part of light (sunlight or the like) incident from the light control film 12 is taken into the solar cell 11 to generate power. Specifically, in the solar cell 11, for example, as illustrated in FIG. 2, when light incident from the back side of the transparent substrate 110 is taken into the photoelectric conversion layer 112, the energy of the incident light in the photoelectric conversion layer 112. As a result, conduction electrons increase and holes and electrons are separated by a built-in electric field (a hole-electron pair is generated). The electric charge generated in this way is taken out through the transparent electrode 111 and the reflective electrode 114, whereby a photocurrent is generated (power generation is performed).

  Here, FIG. 4 schematically shows a cross-sectional structure of a conventional power generation window glass (power generation window glass 100). Thus, in the power generation window glass 100, the photoelectric conversion layer 103 and the pair of transparent electrodes 102 and 104 sandwiching the photoelectric conversion layer 103 are provided on the light incident side of the transparent substrate 101 over the entire area. Further, a transparent substrate 106 is bonded onto the transparent electrode 104 via an adhesive layer 105. With such a stacked structure, light incident from the transparent substrate 106 side is taken into the photoelectric conversion layer 103 and power is generated.

  However, in the structure in which the photoelectric conversion layer 103 is formed on the entire area of the transparent substrate 101 (a structure in which a solar cell is formed on the entire surface of the transparent substrate 101) as in the power generation window glass 100, for example, an oblique view from above. Most of the incident light (sunlight or the like) L1 and the incident light L2 in the front direction are absorbed by the photoelectric conversion layer 103. As a result, almost no light L3 is transmitted through the power generation window glass 100, and the light transmittance is significantly reduced.

  On the other hand, in the present embodiment, the light control film 12 is provided on the light incident surface S1 side of the transparent substrate 10, and the solar cell 11 is a partial region of the transparent substrate 10, specifically, the end portion D. It is provided on the side surface.

  With such a structure, external light first enters the light control film 12. Then, due to the function and structure of the light control film 12 as described above, as shown in FIG. 5A, light (L1) at a predetermined angle (an angle in the scattering region SA shown in FIG. 3A). ) Enters the light control film 12, and the scattered light enters the transparent substrate 10. Of such scattered light based on the incident light L1, the light L1a incident on the transparent substrate 10 at an angle greater than or equal to the critical angle with respect to the light exit surface S2 propagates toward the end D in the transparent substrate 10. The light is received by the solar cell 11 provided at the end D. Of the scattered light, the light L1b incident on the transparent substrate 10 at an angle less than the critical angle with respect to the light exit surface S2 is transmitted through the transparent substrate 10 and exits from the light exit surface S2.

  On the other hand, as shown in FIG. 5B, when light (L2) is incident at a specific angle different from the above (an angle in the non-scattering region SB), no scattering occurs in the light control film 12, and incident light L2 passes through the light control film 12 and the transparent substrate 10 and is emitted from the light exit surface S2 as (transmitted light L3).

  As described above, in the present embodiment, since the light control film 12 is provided on the light incident surface S1 side of the transparent substrate 10, light incident at an angle in the scattering region SA among incident light is transmitted. While conducting power generation by guiding it to the solar cell 11 disposed at the end D, light incident on the non-scattering region SB at an angle is emitted from the light exit surface S2, and the power generation window glass 1 (from the outdoor B) (Toward room A). Therefore, power generation can be performed while suppressing a reduction in transmittance with respect to incident light from a specific direction.

  For example, if the scattering region SA is set in a range of 50 ° to 90 ° which is obliquely upward, since normal sunlight falls from obliquely upward, such solar light is effectively scattered, and the solar cell 11 It is easy to secure the amount of light received at. On the other hand, if the non-scattering region SB is set to include 0 °, it is possible to suppress a reduction in transmittance particularly when the outdoor B is viewed straight from the room A along the horizontal direction (front direction). The field of view of the outdoor B in the front direction seen through the glass can be prevented from becoming dark.

[Example]
For the power generation window glass 1 using the light control film 12 as described above, the following illuminance and power generation characteristics were measured, and the scattering characteristics were evaluated.

(Illuminance measurement)
As an example, as shown in FIG. 6 (A), the light L1 is incident on one surface of a transparent substrate 10 (a glass plate having a thickness of 3 mm) pasted with a light control film (a thickness of 0.5 mm). The illuminance (lx) of light emitted from the end of the transparent substrate 10 (corresponding to the end D) was measured. At this time, as the light control film, a film including 50 ° in the above-described scattering region SA was used, and as the measuring device 120, a solar simulator (HAL-320) was used.

  Moreover, as a comparative example of such an example, the case where nothing is arranged as shown in FIG. 6B (Comparative Example 1) and the transparent substrate 10 (thickness 3 mm) as shown in FIG. The illuminance of the emitted light with respect to the incident light L1 was also measured in the case where only the glass plate was disposed (Comparative Example 2). In either case, the incident light L1 was incident at an illuminance of 23120 (lx) from a direction at an angle of 50 °. The measurement results are shown in FIG.

  As shown in FIG. 7, it can be seen that the illuminance of the emitted light is larger in the example using the light control film 12 than in the comparative example 1 and the comparative example 2 with only the transparent substrate 10. For example, the ratio of the emitted light illuminance to the incident light illuminance (incident light illuminance / emitted light illuminance × 100) is 0.09% in Comparative Example 2, but 0.43% in the Example, which is about 5 times that in Comparative Example 2. It became. Therefore, it can be seen that the amount of light extracted from the end of the transparent substrate 10 is increased by providing the light control film 12 on the light incident surface of the transparent substrate 10.

(Power generation characteristic measurement)
From the above illuminance measurement, it was found that the amount of light from the end of the transparent substrate 10 increased due to the action on the light control film 12, but as a further embodiment, as shown in FIG. The solar cell 11 was disposed, and the power generation characteristics of the solar cell 11 were measured using an electrochemical analyzer 130. Moreover, the measurement for the comparative example 2 was also performed. The results (current-voltage characteristics (IV characteristics)) are shown in FIG. Table 1 below also shows values of the maximum operating point (W), the short circuit current (A), and the open circuit voltage (V).

  From these results, it was found that in the example using the light control film 12, the power generation amount was about 1.8 times that of the comparative example 2 with only the transparent substrate 10, indicating good power generation characteristics.

(Scattering characteristics evaluation)
Further, the scattering characteristics (angle distribution of outgoing light with respect to incident light) were measured for the sample in which the light control film 12 was attached to the transparent substrate 10. At this time, as shown in FIG. 10, the incident angle of the incident light Lin is 0 ° in the direction perpendicular to the in-plane direction of the light control film 12, 90 ° on one end side, and −90 ° on the other end side. The outgoing angle of the outgoing light Lout is shown with the incident angle of the incident light Lin reversed from positive to negative. Further, as the light control film 12, a film in which the scattering region SA was set to 0 ° to 60 ° and the non-scattering region SB was set to −60 ° to −20 ° was used. FIG. 11A shows the angular distribution of each emitted light of light incident from the scattering region SA (incident angles 0 °, 20 °, 40 °, 60 °). FIG. 11B shows an angular distribution of each outgoing light of light incident from the non-scattering region SB (incident angles −60 °, −40 °, −20 °).

  As shown in FIG. 11A, when light enters from the scattering region SA, propagation light (light used for power generation) to the end of the transparent substrate 10 is generated. It can be seen that the angles are dispersed in a region different from the incident angle, and scattering occurs in the light control film 12. On the other hand, as shown in FIG. 11B, the light incident from the non-scattering region SB has the angle of the outgoing light Lout substantially equal to the incident angle, and the light control film 12 is not subjected to the scattering action. It can be seen that it is transparent.

  Next, modified examples (modified examples 1 to 3) of the power generation window glass described in the above embodiment will be described. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

<Modification 1>
FIG. 12 schematically illustrates a cross-sectional configuration of the power generation window glass according to the first modification. The power generation window glass of this modification has the light control film 12 on the light incident surface S1 of the transparent substrate 10 and the solar cell 11 at the end D of the transparent substrate 10 as in the power generation window glass 1 of the above embodiment. It is provided. However, the installation area of the solar cell 11 is different from that of the above-described embodiment, and is provided on the light emission surface S2 of the transparent substrate 10 in this modification. Moreover, it has the area | region 12E in which the light control film 12 is not affixed on the light-incidence surface S1 of the transparent substrate 10, and the solar cell 11 is arrange | positioned facing this area | region 12E. This is because there is no need for scattering in the vicinity of the solar cell, and when the light control film 12 is formed on the facing surface of the solar cell 11, total reflected light on the surface is reduced. By providing the area | region where the light control film 12 is not stuck like the area | region 12E, the quantity of the light totally reflected can be increased. Thus, the light control film 12 does not necessarily have to be provided over the entire light incident surface of the transparent substrate 10. As in this modification, there may be a region where the light control film 12 is not attached depending on the installation location of the solar cell 11 or the like. Even with the configuration as described above, similarly to the above-described embodiment, the light L1a propagating through the transparent substrate 10 due to the scattering action can be taken into the solar cell 11 to generate power.

<Modification 2>
FIG. 13 schematically illustrates a cross-sectional configuration of the power generation window glass according to the second modification. The power generation window glass of this modification has the light control film 12 on the light incident surface S1 of the transparent substrate 10 and the solar cell 11 at the end D of the transparent substrate 10 as in the power generation window glass 1 of the above embodiment. It is provided. However, unlike the above-described embodiment, the installation area of the solar cell 11 is provided on the light incident surface S1 of the transparent substrate 10 in the present modification. Specifically, it has a region 12E where the light control film 12 is not pasted on the light incident surface S1, and the solar cell 11 is arranged in this region 12E. Even in such a configuration, similarly to the above embodiment, the light L1a propagating through the transparent substrate 10 under the action of scattering can be taken into the solar cell 11 to generate power.

  Like the said modification 1, 2, the solar cell 11 may be arrange | positioned not only on the side surface of the transparent substrate 10 in the said embodiment but on the same surface as the light-incidence surface S1 or the light-projection surface S2. In any case, as long as the solar cell 11 is disposed at the end D of the transparent substrate 10, the same effect as the above embodiment can be obtained. However, the arrangement region of the solar cell 11 is not necessarily the end portion D, and may be another portion depending on the use of the power generation window glass as long as it is a partial region of the transparent substrate 10.

<Modification 3>
14A to 14C schematically show a cross-sectional configuration of the power generation glass according to the third modification. The power generation glass of this modification is one in which the solar cell 11 is provided at the end D of the transparent substrate 10 as in the power generation window glass 1 of the above embodiment. However, in this modification, the surface facing the light incident surface S1 of the transparent substrate 10 is the light reflecting surface S3. Specifically, a light reflecting layer 13 made of a metal having light reflectivity such as aluminum (Al) or silver (Ag) is provided on the light reflecting surface S3 of the transparent substrate 10. Further, a scattering film 14 (which may not have scattering anisotropy) is bonded to the light incident surface S1 of the transparent substrate 10. In such a structure, the light reflection layer 13 is provided on the side surface (FIG. 14A), on the light incident surface S1 (FIG. 14B), and on the light reflection surface S3. The present invention can be applied to any case where it is installed (FIG. 14C).

  As in this modification, by using the light reflection layer 13, the incident light L1 is scattered by the scattering film 14, and when a part of the scattered light propagates through the transparent substrate 10, more light is emitted from the solar cell. 11 can be led. Thereby, since the light quantity taken in to a solar cell increases compared with the said embodiment etc., the installation area of a solar cell can be made small. Such a power generation glass can be particularly preferably installed on the wall surface or ceiling of a building.

  Although the present invention has been described with reference to the embodiment and the modifications, the present invention is not limited to the above-described embodiment and the like, and various modifications can be made. For example, in the above-described embodiment, a power generation window glass is used as an example of the power generation apparatus of the present invention, and the case where it is installed on a side wall of a room is described as an example. Is not limited to those described above. For example, the power generation window glass can be applied to a window glass installed on a ceiling such as a skylight.

  Moreover, in the said embodiment etc., the area | region equivalent to the diagonally upper direction at the time of installing power generation window glass is mentioned as an example as scattering area | region SA of the light control film 12, and as a non-scattering area | region SB, a front direction (0 degree ) Is given as an example, but each angle region (angle range) is not limited to that described above, and may be set as appropriate depending on the application of the power generation window glass. In any case, only a part of the light is used for power generation using the scattering action, while the incident light from a specific direction is transmitted as it is, and the reduction of the transmittance in that direction is suppressed. Therefore, an effect equivalent to that of the present invention can be obtained.

  Furthermore, in the above-described embodiments and the like, an organic thin film solar cell has been described as an example of the solar cell of the present invention. However, other solar cells, for example, a silicon hybrid using a silicon thin film (amorphous, microcrystal) The present invention can be applied to a type solar cell, an inorganic solar cell using an inorganic compound such as a III-V group GaAs-based, CdTe-based, or ClGS-based solar cell, and a dye-sensitized solar cell.

  DESCRIPTION OF SYMBOLS 1 ... Electric power generation window glass, 10 ... Transparent substrate, 11 ... Solar cell, 12 ... Light control film, 12A ... 1st refractive index area | region, 12B ... 2nd refractive index area | region, 110 ... Transparent substrate, 111 ... Transparent electrode, 112 ... Photoelectric conversion layer, 113 ... LiF layer, 114 ... reflecting electrode, S1 ... light incident surface, S2 ... light exit surface, SA ... scattering region, SB ... non-scattering region.

Claims (7)

A substrate having a light incident surface and a light output surface facing each other;
A light control layer provided on the light incident surface side of the substrate and having a function of different scattering characteristics depending on an incident angle;
A power generation device comprising: a photoelectric conversion element that receives a part of light emitted from the light control layer. The light control layer causes scattering when light is incident from the first angle region, but does not cause scattering when light is incident from a second angle region different from the first angle region. The power generation device according to claim 1, having a function of transmitting light toward the base body. The power generation device according to claim 1, wherein the light control layer is formed by alternately stacking two refractive index layers having different refractive indexes along a predetermined direction. The power generator according to any one of claims 1 to 3, wherein the base is a transparent substrate. The power generation device according to claim 4, wherein the photoelectric conversion element is provided at an end of the transparent substrate. The power generation device according to claim 5, wherein the photoelectric conversion element is provided on at least a part of a light incident surface, a light emission surface, and a side surface of the transparent substrate. The power generation device according to claim 4, wherein the transparent substrate is a glass substrate.

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