JP2024107856A - Solar Cell Device - Google Patents

Abstract

[Problem] To provide a solar cell device capable of improving aesthetic appearance. [Solution] According to one embodiment, the solar cell device includes a substrate having a first main surface, a second main surface opposite the first main surface, and a first side surface, a first wavelength conversion layer disposed on the first main surface and forming transmitted light of a first color and converting light of a first wavelength into light of a specific wavelength, a second wavelength conversion layer disposed on the first main surface and forming transmitted light of a second color different from the first color and converting light of a second wavelength different from the first wavelength into light of the specific wavelength, a liquid crystal layer facing the second main surface, having cholesteric liquid crystals, and having a reflective surface that reflects light of the specific wavelength toward the substrate out of light incident through the substrate, and a solar cell facing the first side surface and configured to generate electricity using light of the specific wavelength. [Selected Figure] Figure 1

Description

An embodiment of the present invention relates to a solar cell device.

In recent years, various transparent solar cells have been proposed, for example, a display device with a solar cell has been proposed in which a transparent dye-sensitized solar cell is disposed on the surface of the display device.
Also proposed is a solar cell device in which a phosphor layer for converting ultraviolet light into infrared light is disposed between an optical waveguide and a solar cell.

JP 2002-229472 A JP 2022-16955 A

The purpose of the embodiment is to provide a solar cell device that can improve the aesthetic appearance.

A solar cell device according to an embodiment includes:
the first wavelength conversion layer is disposed on the first principal surface and forms transmitted light of a first color and converts light of a first wavelength into light of a specific wavelength; the second wavelength conversion layer is disposed on the first principal surface and forms transmitted light of a second color different from the first color and converts light of a second wavelength different from the first wavelength into light of the specific wavelength; a liquid crystal layer is disposed on the second principal surface and has a cholesteric liquid crystal and has a reflective surface that reflects light of the specific wavelength toward the substrate out of light incident through the substrate; and a solar cell is disposed on the first side surface and configured to generate electricity using light of the specific wavelength.

FIG. 1 is a cross-sectional view illustrating a schematic configuration example of a solar cell device 100. As shown in FIG. FIG. 2 is a diagram for explaining an example of the cholesteric liquid crystal CL contained in the liquid crystal layer 3. As shown in FIG. FIG. 3 is a plan view that diagrammatically illustrates the solar cell device 100. As shown in FIG. FIG. 4 is a diagram showing an example of the external appearance of the solar cell device 100. As shown in FIG. FIG. 5 is a cross-sectional view illustrating a schematic configuration example of the solar cell device 100. As shown in FIG. FIG. 6 is a plan view diagrammatically illustrating another configuration example of the solar cell device 100. As shown in FIG.

The present embodiment will be described below with reference to the drawings. Note that the disclosure is merely an example, and appropriate modifications that a person skilled in the art can easily conceive of while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematic in terms of the width, thickness, shape, etc. of each part compared to the actual embodiment in order to make the explanation clearer, but they are merely an example and do not limit the interpretation of the present invention. In addition, in this specification and each figure, components that perform the same or similar functions as those described above with respect to the previous figures are given the same reference numerals, and duplicate detailed explanations may be omitted as appropriate.

In addition, in the drawings, to facilitate understanding, an X-axis, a Y-axis, and a Z-axis that are perpendicular to each other are shown as necessary. The direction along the Z-axis is called the Z direction or first direction A1, the direction along the Y-axis is called the Y direction or second direction A2, and the direction along the X-axis is called the X direction or third direction A3. The plane defined by the X-axis and Y-axis is called the X-Y plane, the plane defined by the X-axis and Z-axis is called the X-Z plane, and the plane defined by the Y-axis and Z-axis is called the Y-Z plane.

Figure 1 is a cross-sectional view showing a schematic configuration example of a solar cell device 100.

The solar cell device 100 includes a substrate 1, a liquid crystal layer 3, wavelength conversion layers 41 and 42, a light-shielding layer 5, and a solar cell PV. An alignment layer or an adhesive layer may be interposed between the substrate 1 and the liquid crystal layer 3.

The substrate 1 is, for example, made of a glass plate or a synthetic resin plate. The substrate 1 may be flexible. The substrate 1 may have any shape. The substrate 1 may be curved.
The substrate 1 has optical transparency that transmits at least a part of incident light. The substrate 1 is, for example, a transparent glass plate, but may be an opaque (semi-transparent) glass plate such as frosted glass. In this specification, "transparent" preferably means colorless transparency, but may also mean colored transparency.

In this specification, "light" includes visible light and invisible light. For example, the lower limit of the visible light range is 360 nm to 400 nm, and the upper limit of the visible light range is 760 nm to 830 nm. Visible light includes a first component (blue component) in a first wavelength band (e.g., 400 nm to 500 nm), a second component (green component) in a second wavelength band (e.g., 500 nm to 600 nm), and a third component (red component) in a third wavelength band (e.g., 600 nm to 700 nm). Invisible light includes the ultraviolet wavelength band, which is shorter than the first wavelength band, and the infrared wavelength band, which is longer than the third wavelength band.

The substrate 1 is formed in a flat plate shape along the XY plane, and has a main surface (outer surface) F1, a main surface (inner surface) F2, a side surface S1, and a side surface S2. The main surface F1 and the main surface F2 are surfaces that are approximately parallel to the XY plane, and face each other in the first direction A1. In one example, both the main surface F1 and the main surface F2 are flat surfaces. At least one of the main surface F1 and the main surface F2 may have minute irregularities or a pattern.
The side surface S1 and the side surface S2 are surfaces that are approximately parallel to the XZ plane and face each other in the second direction A2.

The liquid crystal layer 3 faces the main surface F2 of the substrate 1 in the first direction A1. In the illustrated example, the liquid crystal layer 3 is in contact with the main surface F2. As shown enlarged and schematic, the liquid crystal layer 3 has cholesteric liquid crystal CL. The cholesteric liquid crystal CL has a helical axis AX that is substantially parallel to the first direction A1, and also has a helical pitch P along the first direction A1. The helical pitch P indicates one period of the helix (the layer thickness along the helical axis AX required for the liquid crystal molecules to rotate 360 degrees).

Such a liquid crystal layer 3 is configured to reflect circularly polarized light in a selective reflection band determined according to the helical pitch P and the refractive index anisotropy Δn of the liquid crystal layer 3, out of the light LTi incident on the solar cell device 100. In this specification, "reflection" in the liquid crystal layer 3 involves diffraction inside the liquid crystal layer 3.

The liquid crystal layer 3 has a reflecting surface 3R that reflects circularly polarized light corresponding to the rotation direction of the cholesteric liquid crystal CL within the selective reflection band. The reflecting surface 3R is inclined with respect to the X-Y plane. Note that in this specification, the circularly polarized light may be strictly circularly polarized light or may be circularly polarized light that approximates elliptically polarized light.

In the example shown in FIG. 1, the liquid crystal layer 3 is configured to reflect a portion of the light LTi incident from the main surface F1 side toward the substrate 1.

In the solar cell device 100, the liquid crystal layer 3 shown in FIG. 1 may be multi-layered to have other cholesteric liquid crystals. The other cholesteric liquid crystals include, for example, cholesteric liquid crystals having a helical pitch different from the helical pitch P shown in the figure, or cholesteric liquid crystals that are rotated in the opposite direction to the rotation direction of the cholesteric liquid crystal CL shown in the figure.

The wavelength conversion layers 41 and 42 are disposed on the main surface F1. In the illustrated example, the wavelength conversion layers 41 and 42 are in contact with the main surface F1.
The wavelength conversion layer 41 has a function of converting light having a first wavelength λ1 out of the incident light into light having a specific wavelength.
The wavelength conversion layer 42 has a function of converting light having the second wavelength λ2 out of the incident light into light having a specific wavelength.

The second wavelength λ2 is a wavelength different from the first wavelength λ1. The first wavelength λ1 and the second wavelength λ2 are included in any wavelength band of visible light, but may be included in the ultraviolet wavelength band. The specific wavelength is a wavelength included in the selective reflection band of the liquid crystal layer 3, and in one example, is included in the infrared wavelength band. The specific wavelength converted by the wavelength conversion layer 41 and the specific wavelength converted by the wavelength conversion layer 42 may be different wavelengths from each other.

These wavelength conversion layers 41 and 42 contain wavelength conversion materials such as phosphors and quantum dots. In the illustrated example, the wavelength conversion layers 41 and 42 are spaced apart from each other, but they may be adjacent to each other. Also, a portion of the wavelength conversion layer 41 may overlap a portion of the wavelength conversion layer 42.

The light-shielding layer 5 forms the outline of each of the wavelength conversion layers 41 and 42. As shown in the figure, when the wavelength conversion layers 41 and 42 are spaced apart from each other, the light-shielding layer 5 is formed so as to border the wavelength conversion layers 41 and 42. When the wavelength conversion layers 41 and 42 are adjacent to each other, the light-shielding layer 5 is formed at the boundary between the wavelength conversion layers 41 and 42.
Such a light-shielding layer 5 is made of a material that blocks at least visible light, or alternatively, the light-shielding layer 5 is made of a material that blocks visible light and transmits light of a specific wavelength.

The solar cell PV faces the side surface S1 in the second direction A2. In the illustrated example, the solar cell PV is in contact with the side surface S1. The solar cell PV is configured to receive light of a specific wavelength and generate electricity.
Examples of solar cells PV include silicon-based solar cells, organic thin-film solar cells, etc. Silicon-based solar cells are formed using amorphous silicon, microcrystalline silicon, single crystal silicon, polycrystalline silicon, etc. Organic thin-film solar cells include organic semiconductor solar cells, perovskite solar cells, etc., and may have optical transparency depending on the material used.

Next, we will explain the optical function of the solar cell device 100 shown in Figure 1.

The light LTi incident on the solar cell device 100 includes, for example, visible light, ultraviolet light, and infrared light. In the example shown in FIG. 1, for ease of understanding, the light LTi is assumed to be incident approximately perpendicularly to the substrate 1. Note that the angle of incidence of the light LTi with respect to the substrate 1 is not particularly limited.

The light LTi is incident on the wavelength conversion layers 41 and 42 .
In the wavelength conversion layer 41, the light having the first wavelength λ1 of the light LTi is converted into light having a specific wavelength. The light transmitted through the wavelength conversion layer 41 is separated into light LTc having the specific wavelength and the other light LTt1.
In the wavelength conversion layer 42, the light having the second wavelength λ2 of the light LTi is converted into light having a specific wavelength. The light transmitted through the wavelength conversion layer 42 is separated into light LTc having a specific wavelength and the other light LTt2.

Both the light LTt1 and the light LTt2 are transmitted through the substrate 1 and the liquid crystal layer 3. The transmission spectra of the light LTt1 and the light LTt2 are different from each other. That is, the light LTt1 is a transmitted light of a first color, whereas the light LTt2 is a transmitted light of a second color different from the first color.
For example, when the light LTi is white light, when blue light having the first wavelength λ1 is converted into light of a specific wavelength in the wavelength conversion layer 41, the light LTt1 exhibits a yellowish color including green and red components.
When the green light component is converted into light of a specific wavelength as the second wavelength λ2 in the wavelength conversion layer 42, the light LTt2 exhibits a magenta color including blue and red components.
Furthermore, when red light is converted into light of a specific wavelength in the wavelength conversion layer, the transmitted light exhibits a cyan color containing blue and green components.

The light LTc converted to a specific wavelength by the wavelength conversion layers 41 and 42 passes through the substrate 1 and enters the liquid crystal layer 3. The liquid crystal layer 3 then reflects a portion of the light LTc at the reflecting surface 3R. The reflected light LTr is circularly polarized light of a specific wavelength. For example, if the light LTr is right-handed circularly polarized light, left-handed circularly polarized light passes through the liquid crystal layer 3. As described above, if the liquid crystal layer 3 has cholesteric liquid crystals that are rotated in the opposite direction to the cholesteric liquid crystal CL shown in the figure, the liquid crystal layer 3 can reflect right-handed circularly polarized light and left-handed circularly polarized light, respectively. In other words, the liquid crystal layer 3 can reflect both right-handed circularly polarized light and left-handed circularly polarized light for light of a specific wavelength.

Between the wavelength conversion layer 41 and the wavelength conversion layer 42, the light LTi incident on the substrate 1 passes through the substrate 1 except for light of a specific wavelength. The light of the specific wavelength is reflected by the liquid crystal layer 3 in the same manner as the light LTc.

The light LTi that enters the light-shielding layer 5 is mostly absorbed. However, if the light-shielding layer 5 is made of a material that transmits light of a specific wavelength, the light of the specific wavelength that passes through the light-shielding layer 5 is reflected by the liquid crystal layer 3 in the same way as the light LTc.

The approach angle θ of the light LTr reflected by the liquid crystal layer 3 is set to satisfy the optical waveguide condition. The approach angle θ here corresponds to an angle equal to or greater than the critical angle at which total reflection occurs at the interface between the liquid crystal layer 3 and the air. The approach angle θ indicates the angle with respect to the normal N of the substrate 1.

When the substrate 1 and the liquid crystal layer 3 have the same refractive index, the laminate of these can become a single light guide element. In this case, the light LTr is repeatedly reflected at the interface between the substrate 1 and the air, and at the interface between the liquid crystal layer 3 and the air, and is guided toward the side surface S1.

The solar cell PV receives the light LTr emitted from the side surface S1 and generates electricity.

Note that, although the specific wavelength is described here as being within the infrared wavelength band, it is preferable that the specific wavelength be set to a wavelength that provides high power generation efficiency in the solar cell PV.

The solar cell device 100 may also have three or more types of wavelength conversion layers.

Figure 2 is a diagram illustrating an example of the cholesteric liquid crystal CL contained in the liquid crystal layer 3.

In FIG. 2, the liquid crystal layer 3 is illustrated enlarged in the first direction A1. For simplicity, one liquid crystal molecule LM out of multiple liquid crystal molecules located on the same plane parallel to the X-Y plane is illustrated as the liquid crystal molecule that constitutes the cholesteric liquid crystal CL. The orientation direction of the illustrated liquid crystal molecule LM corresponds to the average orientation direction of multiple liquid crystal molecules located on the same plane.

Focusing on one cholesteric liquid crystal CL surrounded by a dotted line, the cholesteric liquid crystal CL is composed of multiple liquid crystal molecules LM that are stacked in a spiral shape along the first direction A1 while rotating. The multiple liquid crystal molecules LM include a liquid crystal molecule LM11 that is located near the interface between the substrate 1 and the liquid crystal layer 3.

2, the alignment directions of the plurality of cholesteric liquid crystals CL adjacent to each other along the second direction A2 are different from each other. In addition, the spatial phases of the cholesteric liquid crystals CL adjacent to each other along the second direction A2 are different from each other.
The alignment directions of the liquid crystal molecules LM11 adjacent to each other along the second direction A2 are different from each other. The alignment directions of the liquid crystal molecules LM11 change continuously along the second direction A2.

The reflecting surface 3R of the liquid crystal layer 3, indicated by the dashed line in the figure, is inclined with respect to the XY plane. The angle θα between the reflecting surface 3R and the XY plane is an acute angle. The reflecting surface 3R corresponds to a surface on which the orientation direction of the liquid crystal molecules LM is uniform, or a surface on which the spatial phase is uniform (an equiphase surface).

Such a liquid crystal layer 3 is hardened with the alignment direction of the liquid crystal molecules LM fixed. In other words, the alignment direction of the liquid crystal molecules LM is not controlled according to an electric field. For this reason, the solar cell device 100 does not have electrodes for forming an electric field in the liquid crystal layer 3.

In general, in a liquid crystal layer 3 having a cholesteric liquid crystal CL, the selective reflection band Δλ for perpendicularly incident light is expressed by the following formula (1) based on the helical pitch P of the cholesteric liquid crystal CL and the refractive index anisotropy Δn (the difference between the refractive index ne for extraordinary light and the refractive index no for ordinary light) of the liquid crystal layer 3.
Δλ=Δn*P…(1)
A specific wavelength range of the selective reflection band Δλ is a range from (no*P) to (ne*P).
The central wavelength λm of the selective reflection band Δλ is expressed by the following formula (2) based on the helical pitch P of the cholesteric liquid crystal CL and the average refractive index nav (=(ne+no)/2) of the liquid crystal layer 3.
λm=nav*P…(2)

Figure 3 is a plan view showing a schematic diagram of the solar cell device 100.

Figure 3 shows an example of the spatial phase of the cholesteric liquid crystal CL. The spatial phase shown here is shown as the orientation direction of the liquid crystal molecule LM11 located near the substrate 1 among the liquid crystal molecules LM contained in the cholesteric liquid crystal CL.

The alignment directions of the liquid crystal molecules LM11 of the cholesteric liquid crystals CL aligned along the second direction A2 are different from each other, that is, the spatial phases of the cholesteric liquid crystals CL are different along the second direction A2.
On the other hand, the alignment directions of the liquid crystal molecules LM11 of the cholesteric liquid crystals CL aligned along the third direction A3 are substantially the same, that is, the spatial phases of the cholesteric liquid crystals CL are substantially the same in the third direction A3.

In particular, when focusing on the cholesteric liquid crystal CL aligned in the second direction A2, the alignment direction of each liquid crystal molecule LM11 differs by a certain angle. In other words, the alignment direction of the multiple liquid crystal molecules LM11 aligned along the second direction A2 changes linearly. Therefore, the spatial phase of the multiple cholesteric liquid crystals CL aligned along the second direction A2 changes linearly along the second direction A2. As a result, a reflecting surface 3R that is inclined with respect to the X-Y plane is formed, as in the liquid crystal layer 3 shown in FIG. 2. Here, "linearly changing" indicates, for example, that the amount of change in the alignment direction of the liquid crystal molecule LM11 is expressed by a linear function. Note that the alignment direction of the liquid crystal molecule LM11 here corresponds to the long axis direction of the liquid crystal molecule LM11 in the X-Y plane.

Here, the interval between two liquid crystal molecules LM11 when the alignment direction of the liquid crystal molecules LM11 changes by 180 degrees along the second direction A2 in one plane is defined as the period T. In FIG. 3, DP indicates the rotation direction of the liquid crystal molecules LM11. The inclination angle θα of the reflecting surface 3R shown in FIG. 2 is appropriately set by the period T and the helical pitch P. In one example, the period T is 1000 nm to 3000 nm.

Figure 4 shows an example of the external appearance of the solar cell device 100.

In the illustrated example, wavelength conversion layer 41 is formed in a cloud shape, wavelength conversion layer 42 is formed in a moon shape, and wavelength conversion layer 43 is formed in a mountain shape. The light shielding layer 5 is formed to surround each of the wavelength conversion layers 41 to 43, forming the outline of each wavelength conversion layer. The transmitted light of each of the wavelength conversion layers 41 to 43 exhibits a different color. In addition, each of the wavelength conversion layers 41 to 43 has the function of converting a portion of the wavelength of the incident light into a specific wavelength that can be used for power generation by the solar cell PV.

The light LTt1 transmitted through the wavelength conversion layer 41 exhibits a first color. Furthermore, the light LTc having a specific wavelength converted by the wavelength conversion layer 41 is reflected by the liquid crystal layer 3 and then guided toward the solar cell PV.
The light LTt2 transmitted through the wavelength conversion layer 42 exhibits a second color. Furthermore, the light LTc having a specific wavelength converted by the wavelength conversion layer 42 is reflected by the liquid crystal layer 3 and then guided toward the solar cell PV.
The light LTt3 transmitted through the wavelength conversion layer 43 exhibits a third color. The light LTc having a specific wavelength converted by the wavelength conversion layer 43 is reflected by the liquid crystal layer 3 and then guided toward the solar cell PV.
The first color, the second color, and the third color are different from each other.

Therefore, the solar cell device 100 can generate electricity by utilizing a portion of the light LTi that is directly incident on the substrate 10 and the light LTc that is converted by the wavelength conversion layers 41 to 43, while achieving a stained glass-like appearance and improving the aesthetic appearance.
Furthermore, by using a plurality of types of wavelength conversion layers that transmit light of different colors, it is possible to freely create patterns.
In addition, each of the wavelength conversion layers 41 to 43 is bordered by the light-shielding layer 5, so that the contours can be emphasized and the design can be improved.
Furthermore, when the light-shielding layer 5 is formed of a material that transmits specific wavelengths that can be used for power generation, the amount of power generation can be improved compared to when the light-shielding layer 5 blocks the specific wavelengths.

In addition, in order to prioritize design, non-power generating regions may be formed between the wavelength conversion layers. The non-power generating regions here may be black regions that absorb almost all of the light LTi, or regions where the wavelength conversion layers are placed but where the wavelength of the converted light is different from the specific wavelength, or regions where light of the specific wavelength is not obtained.

Figure 5 is a cross-sectional view showing a schematic diagram of another example configuration of the solar cell device 100.

The configuration example shown in FIG. 5 differs from the configuration example shown in FIG. 1 in that the solar cell device 100 further includes a transparent protective substrate 11.

The protective substrate 11 is made of, for example, a glass plate or a synthetic resin plate. The protective substrate 11 is formed in a flat plate shape along the XY plane and has a main surface F11, a main surface F12, a side surface S11, and a side surface S12.
The main surface F11 and the main surface F12 are surfaces substantially parallel to the XY plane and face each other in the first direction A1. The main surface F12 faces the main surface F1 of the substrate 1 in the first direction A1.
The side surface S11 and the side surface S12 are surfaces that are approximately parallel to the XZ plane and face each other in the second direction A2. The side surface S11 is located directly above the side surface S1 in the first direction A1. The side surface S12 is located directly above the side surface S2 in the first direction A1.

The wavelength conversion layers 41 and 42 are sandwiched between the substrate 1 and the protective substrate 11. In the illustrated example, the wavelength conversion layers 41 and 42 are in contact with the main surface F1 and the main surface F12.

The solar cell PV1 faces the side surface S1 and the side surface S11 in the second direction A2. In the illustrated example, the solar cell PV1 is in contact with the side surface S1 and the side surface S11.
The solar cell PV2 faces the side surface S2 and the side surface S12 in the second direction A2. In the illustrated example, the solar cell PV2 is in contact with the side surface S2 and the side surface S12.

In such a solar cell device 100, a portion of the light LTi transmitted through the protective substrate 11 is converted into light of a specific wavelength in the wavelength conversion layer 41 and the wavelength conversion layer 42.

At this time, the light of the specific wavelength converted by the wavelength conversion layer 41 includes light LTc10, light LTc11, and light LTc12.
The light LTc10 passes through the substrate 1, is reflected by the reflecting surface 3R of the liquid crystal layer 3, is guided toward the side surface S1, and is used for power generation in the solar cell PV1.
The light LTc11 is incident on the protective substrate 11, guided toward the side surface S11, and used for power generation in the solar cell PV1.
The light LTc12 is incident on the protective substrate 11, guided toward the side surface S12, and used for power generation in the solar cell PV2.

Similarly, the light of the specific wavelength converted by the wavelength conversion layer 42 includes light LTc20, light LTc21, and light LTc22.
The light LTc20 passes through the substrate 1, is reflected by the reflecting surface 3R of the liquid crystal layer 3, is guided toward the side surface S1, and is used for power generation in the solar cell PV1.
The light LTc21 is incident on the protective substrate 11, guided toward the side surface S11, and used for power generation in the solar cell PV1.
The light LTc22 is incident on the protective substrate 11, guided toward the side surface S12, and used for power generation in the solar cell PV2.

In this way, even if the light converted by the wavelength conversion layers 41 and 42 is scattered in various directions, this light can be used for power generation, thereby improving the power generation efficiency.
Furthermore, since the wavelength conversion layers 41 and 42 are covered with the protective substrate 11 , deterioration of the wavelength conversion layers 41 and 42 and falling off of the substrate 1 can be suppressed.

In the example shown in FIG. 5, a case has been described in which the solar cell device 100 has solar cells PV1 and PV2 along two sides, but this is not limited thereto.

Figure 6 is a plan view that shows a schematic diagram of another configuration example of the solar cell device 100.

In the configuration example shown in FIG. 6, the solar cell device 100 includes solar cells PV1 to PV4 along the four sides.
The solar cell PV1 faces a side surface S1 of the substrate 1 and a side surface S11 of the protection substrate 11.
The solar cell PV2 faces the side surface S2 of the substrate 1 and the side surface S12 of the protection substrate 11.
The solar cell PV3 faces the side surface S3 of the substrate 1 and the side surface S13 of the protection substrate 11.
The solar cell PV4 faces a side surface S4 of the substrate 1 and a side surface S14 of the protective substrate 11.

As a result, when light converted to a specific wavelength is scattered in the wavelength conversion layers 41 and 42 shown in Figure 5, it can be used to generate electricity regardless of the direction in which it is guided.

As described above, this embodiment can provide a solar cell device that can generate electricity while improving aesthetics.

In the above-described embodiment, for example, the wavelength conversion layer 41 corresponds to the first wavelength conversion layer, and the wavelength conversion layer 42 corresponds to the second wavelength conversion layer.
In the substrate 1, the main surface F1 corresponds to the first main surface, the main surface F2 corresponds to the second main surface, and the side surface S1 corresponds to the first side surface.
In addition, in the protection substrate 11, the side surface S11 corresponds to the second side surface.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents as set forth in the claims.

Reference Signs List 100...Solar cell device 1...Substrate F1, F2...Main surfaces S1, S2...Side surfaces 3...Liquid crystal layer CL...Cholesteric liquid crystal 3R...Reflective surface 41...Wavelength conversion layer 42...Wavelength conversion layer 5...Light-shielding layer 11...Protective substrate F11, F12...Main surfaces S11, S12...Side surfaces PV, PV1, PV2, PV3, PV4...Solar cell

Claims (6)

a substrate having a first main surface, a second main surface opposite the first main surface, and a first side surface;
a first wavelength conversion layer disposed on the first main surface, the first wavelength conversion layer forming a transmitted light of a first color and converting light of a first wavelength into light of a specific wavelength;
a second wavelength conversion layer disposed on the first main surface, forming transmitted light of a second color different from the first color and converting light of a second wavelength different from the first wavelength into light of the specific wavelength;
a liquid crystal layer facing the second main surface, the liquid crystal layer having a reflective surface including a cholesteric liquid crystal and configured to reflect, toward the substrate, light having the specific wavelength among light incident through the substrate;
A solar cell facing the first side surface and configured to generate electricity using light of the specific wavelength;
A solar cell device comprising: The solar cell device according to claim 1, further comprising a light-shielding layer that defines the contours of each of the first wavelength conversion layer and the second wavelength conversion layer. The solar cell device according to claim 2, wherein the light-shielding layer transmits the specific wavelength. In addition, it has a transparent protective substrate,
The solar cell device according to claim 1 , wherein the first wavelength conversion layer and the second wavelength conversion layer are sandwiched between the substrate and the protection substrate. the protection substrate has a second side surface located directly above the first side surface,
The solar cell device according to claim 4 , wherein the solar cell faces the first side surface and the second side surface. The solar cell device according to any one of claims 1 to 5, wherein the specific wavelength is in the infrared wavelength band.

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