Solar cells, laminates, and structures

Abstract

This increases the power generation of solar cells that transmit visible light. [Solution] The solar cell 10 comprises an optical member 30 having a first surface 31 and a second surface 32 located on the opposite side of the first surface 31, and a power generation layer 20 provided on the second surface 32 side of the optical member 30. The optical member 30 has a plurality of prism portions 35, and at least a portion of the first surface 31 is formed by the plurality of prism portions 35.

Description

[Technical Field]

[0001] This disclosure relates to solar cells, laminates, and structures. [Background technology]

[0002] Solar power generation is known as a power generation method with a low environmental impact. Solar cells are used in this type of power generation. Solar cells are batteries that convert light into electricity. Furthermore, solar cells with high transmittance in the visible light region that can be installed in the windows of buildings are known (for example, Patent Document 1). With such solar cells, power generation can be carried out while collecting visible light into the building through the window on which the solar cell is installed. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-107850 [Overview of the project] [Problems that the invention aims to solve]

[0004] In solar cells that transmit visible light, there is a need to efficiently utilize sunlight to increase power generation.

[0005] This disclosure has been made in consideration of the above points and aims to increase the power generation of solar cells that transmit visible light. [Means for solving the problem]

[0006] The solar cell of this disclosure comprises an optical member having a first surface and a second surface located opposite to the first surface, The optical member comprises a power generation layer provided on the second surface side, The optical component is a solar cell that transmits visible light, having a plurality of prism sections, and at least a portion of the first surface is formed by the plurality of prism sections. [Effects of the Invention]

[0007] According to this disclosure, the power generation of solar cells that transmit visible light can be increased. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing a solar cell according to one embodiment. [Figure 2] Figure 2 is a cross-sectional view showing a solar cell according to one embodiment. [Figure 3] Figure 3 is a perspective view showing a solar cell according to one embodiment. [Figure 4] Figure 4 is a cross-sectional view showing a solar cell according to an comparative example. [Figure 5] Figure 5 is a cross-sectional view showing a laminate and a structure according to one embodiment. [Figure 6] Figure 6 is a cross-sectional view showing a laminate according to Modification 1. [Figure 7] Figure 7 is a cross-sectional view showing a laminate according to Modification 2. [Figure 8] Figure 8 is a cross-sectional view showing a solar cell according to Modification 3. [Figure 9] Figure 9 is a cross-sectional view showing a solar cell according to Modification 4. [Modes for carrying out the invention]

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, the scale and aspect ratios of the dimensions have been appropriately changed and exaggerated from those of the actual objects for the sake of illustration and ease of understanding. Some configurations shown in some drawings may be omitted in other drawings.

[0010] In this specification, terms that specify a shape or geometric condition, and the degree of such a shape or the like, such as "parallel", "orthogonal", "perpendicular", "identical", etc., or values of length or angle, etc. are not limited to a strict meaning, and are interpreted to include a range within which similar functions can be expected.

[0011] To clarify the relationship of directions between drawings, in some drawings, a common direction is indicated by arrows with common reference signs attached. An arrow pointing into the depth along the direction perpendicular to the plane of the drawing is indicated by a symbol with an X inside a circle, as shown in FIG. 1 for example. The number of prism portions 35 described later in the drawings may be appropriately changed and represented for each drawing from the viewpoint of simplification of the drawings.

[0012] In this specification, terms such as "sheet", "film", and "plate" are not distinguished from each other based only on the difference in name. For example, a "sheet" cannot be distinguished from a member called a film or a plate only by the difference in name.

[0013] In this specification, when a plurality of upper limit value candidates and a plurality of lower limit value candidates are listed for a parameter, the parameter may be a numerical range obtained by combining any one upper limit value candidate and any one lower limit value candidate.

[0014] One embodiment of the present disclosure relates to the following [1] to [8].

[0015] [1] An optical member having a first surface and a second surface located on the opposite side of the first surface, and a power generation layer provided on the second surface side of the optical member, wherein the optical member has a plurality of prism portions, and at least a part of the first surface is formed by the plurality of prism portions, and the solar cell transmits visible light.

[0016] [2] The solar cell according to [1], further comprising a corresponding optical member having a corresponding surface that is spaced apart from the first surface of the optical member and has a shape corresponding to the first surface.

[0017] [3] Each of the prism portions extends along a first direction parallel to the second surface and is arranged from the first side to the second side along a second direction that is parallel to the second surface and perpendicular to the first direction. Each of the prism portions includes a first inclined surface facing the first side of the second direction in a cross section perpendicular to the first direction, and a second inclined surface facing the second side of the second direction in a cross section perpendicular to the first direction. The solar cell according to [2], wherein the first inclined surface is larger than the second inclined surface.

[0018] [4] The solar cell according to [3], further comprising a reflective layer provided on the second inclined surface of each of the prism portions.

[0019] [5] A solar cell according to any one of [1] to [4], further comprising a wavelength-selective reflective layer provided on the first surface of the optical member, which selectively reflects light containing wavelengths that the power generation layer can use to generate electricity.

[0020] [6] Each of the prism portions extends along a first direction parallel to the second surface and is arranged from the first side to the second side along a second direction that is parallel to the second surface and perpendicular to the first direction. Each of the prism portions includes a first inclined surface facing the first side of the first direction in a cross section perpendicular to the first direction, and a second inclined surface facing the second side of the first direction in a cross section perpendicular to the first direction. The first inclined surface is larger than the second inclined surface. The solar cell according to [5], wherein the wavelength-selective reflective layer is provided on at least the first inclined surface.

[0021] [7] A solar cell as described in any one of [1] to [6], A laminate that is fitted into an opening in a building, comprising a light-transmitting member superimposed on the aforementioned solar cell.

[0022] [8] The opening and A building comprising a laminate described in [7] fitted into the opening.

[0023] Next, an embodiment of the present disclosure will be described with reference to Figures 1 to 3 and Figure 5. The solar cell 10 is a battery that supplies power when irradiated with light. That is, the solar cell 10 is a battery that converts light energy into electrical energy. The solar cell 10 can supply power not only from sunlight, but also from illumination light or image light, etc.

[0024] Figure 1 is a cross-sectional view showing an example of a solar cell 10 according to this embodiment. Figure 1 corresponds to a cross-sectional view obtained by cutting the solar cell 10 in a cross section perpendicular to the first direction d1, which will be described later. As shown in Figure 1, the solar cell 10 comprises an optical member 30 and a power generation layer 20. In the example shown in Figure 1, the solar cell 10 further comprises a substrate 3 and a circuit 5. The solar cell 10 is configured to supply the power generated when light is irradiated onto the solar cell 10 to a power-consuming device (not shown) or a power-storing battery (not shown) via the circuit 5.

[0025] The constituent materials and structure of the portion of the solar cell 10 that generates electricity when irradiated with light (the power generation layer 20, described later) are not particularly limited, as long as the solar cell 10 transmits visible light as described later. The solar cell 10 that transmits visible light in this embodiment may be a polymer solar cell, a dye-sensitized solar cell, a CIGS-type solar cell, an amorphous silicon solar cell, a cadmium telluride (CdTe) solar cell, a quantum dot solar cell, or a perovskite solar cell.

[0026] The substrate 3 is a component for supporting the optical component 30 and the power generation layer 20. In the example shown in Figure 1, the substrate 3 supports the optical component 30, the power generation layer 20, and the circuit 5. The substrate 3 may be a plate-shaped component. The thickness of the substrate 3 may be 1 μm or more, 25 μm or more, 10 mm or less, or 500 μm or less. The substrate 3 is made of an insulator. The material of the substrate 3 may be an inorganic material such as glass. The material of the substrate 3 may be a plastic material such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cycloolefin polymer, or polyimide. Furthermore, the material of the substrate 3 may be a composite material such as a nanocomposite.

[0027] Circuit 5 electrically connects the solar cell 10 to an object outside the solar cell 10. Circuit 5 may also electrically connect the solar cell 10 to a power-consuming device (not shown). Circuit 5 may also electrically connect the solar cell 10 to a power-storage battery (not shown). Although not shown, circuit 5 may also electrically connect multiple solar cells 10 to each other.

[0028] As an example, in a plan view of the solar cell 10, the circuit 5 extends in a linear manner. The circuit 5 is made of a conductive material such as copper. If the circuit 5 electrically connects multiple solar cells 10, the circuit 5 may also include diodes (not shown) to bypass solar cells 10 that are unable to generate power due to shading or malfunction.

[0029] As shown in Figure 1, circuit 5 includes a first connection part 6 and a second connection part 7. In the example shown in Figure 1, the first connection part 6 is connected to the first electrode layer 21 of the solar cell 10, which will be described later. The second connection part 7 is connected to the second electrode layer 22 of the solar cell 10, which will be described later.

[0030] As shown in Figure 1, the solar cell 10 comprises an optical member 30 having a first surface 31 and a second surface 32 located opposite the first surface 31, and a power generation layer 20 provided on the second surface 32 side of the optical member 30. In the example shown in Figure 1, the power generation layer 20 is arranged between the substrate 3 and the optical member 30. Thus, in this embodiment, the surface of the substrate 3 constitutes the incident surface 11 of the solar cell 10. Furthermore, the first surface 31 of the optical member 30 constitutes the surface opposite to the incident surface 11 of the solar cell 10. In this embodiment, along the thickness direction d3 of the solar cell 10, the substrate 3, the power generation layer 20, and the optical member 30 are arranged in this order from the incident surface 11 side. The thickness direction d3 of the solar cell 10 is a direction perpendicular to both the first direction d1 and the second direction d2, which will be described later. In this embodiment, the second surface 32 of the optical member 30 is a plane. In this embodiment, the thickness direction d3 is perpendicular to the second surface 32.

[0031] The optical component 30 of the solar cell 10 is a component that changes the direction of light propagation that enters the solar cell 10. Specifically, the optical component 30 is a component that lengthens the range of light within the power generation layer 20.

[0032] The optical member 30 will be further described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view of the solar cell 10 taken in a section perpendicular to the first direction d1, which will be described later. Figure 3 is a perspective view of the solar cell 10. In Figures 2 and 3, and in Figures 4 and 6 to 9 described later, the internal elements of the power generation layer 20 are omitted from the illustration, and the external shape of the power generation layer 20 is shown. In Figures 2 and 3, and in Figures 4 and 6 to 9 described later, the circuit 5 is omitted from the illustration. As shown in Figures 2 and 3, the optical member 30 has a plurality of prism portions 35. At least a part of the first surface 31 is formed by the plurality of prism portions 35. In the example shown in Figures 2 and 3, the entire first surface 31 is formed by the plurality of prism portions 35.

[0033] The main body portion 33 of the optical component 30 supports the prism portion 35. The main body portion 33 is flat.

[0034] As shown in Figures 2 and 3, each prism section 35 extends along a first direction d1 parallel to the second surface 32 of the optical member 30. The direction parallel to the second surface 32 of the optical member 30 and perpendicular to the first direction d1 is referred to as the second direction d2. One side in the second direction d2 is referred to as the first side s21. The side in the second direction d2 opposite to the first side s21 is referred to as the second side s22. Each prism section 35 is arranged along the second direction d2.

[0035] In the example shown in Figure 2, the cross-sectional shape of the prism portion 35 in a cross-section perpendicular to the first direction d1 is triangular. The cross-sectional shape of the prism portion 35 can be determined based on the difference between the refractive index of the prism portion 35 and the refractive index of the outside of the optical member 30, so as to ensure that the function of the prism portion 35, described later, is sufficiently obtained. The refractive index of the prism portion 35 may be 1.45 or higher, or 1.95 or lower.

[0036] In the example shown in Figure 2, each prism portion 35 includes a first inclined surface 35a facing the first side s21 of the second direction d2 in a cross section perpendicular to the first direction d1, and a second inclined surface 35b facing the second side s22 of the second direction d2 in a cross section perpendicular to the first direction d1. The first inclined surface 35a and the second inclined surface 35b each form a part of the first surface 31 of the optical member 30. The first inclined surface 35a and the second inclined surface 35b are surfaces inclined with respect to the second surface 32, in other words, surfaces that are not parallel to the second surface 32. In each prism portion 35, the first inclined surface 35a is larger than the second inclined surface 35b.

[0037] In the example shown in Figure 2, the angle θ1 between the second surface 32 and the first inclined surface 35a is greater than the angle θ2 between the second surface 32 and the second inclined surface 35b. The angle θ1 is, for example, 40° or less. The angle θ1 may also be 30° or less, or 20° or less. The angle θ1 is, for example, 5° or more. The angle θ1 may also be 10° or more, or 15° or more. From the viewpoint of increasing the ratio of the area of ​​the first inclined surface 35a to the area of ​​the second inclined surface 35b, it is preferable that the angle θ2 is large, with an upper limit of 90°. The angle θ2 may also be 75° or more, or 80° or more, or 90°. In the examples shown in Figures 2 and 3, the angle θ2 is 90°. By having angles θ1 and θ2 within the above numerical ranges, the action of the prism section 35, which will be described later, is exerted more effectively.

[0038] The function of the prism section 35 will now be explained. Consider the case where the solar cell 10 is positioned such that the second direction d2 is parallel to the vertical direction, the first side s21 is directed upward in the vertical direction, and the second side s22 is directed downward in the vertical direction, as shown in Figure 2. In this case, the prism section 35 is configured to easily reflect light that enters the incident surface 11 of the solar cell 10 from diagonally upward in the vertical direction and reaches the first surface 31 into the optical member 30.

[0039] In the example shown in Figure 2, the prism section 35 includes a first inclined surface 35a and a second inclined surface 35b, with the first inclined surface 35a being larger than the second inclined surface 35b. Because the first inclined surface 35a is larger than the second inclined surface 35b, light incident on the incident surface 11 of the solar cell 10 from a vertically oblique upward direction is more likely to reach the first inclined surface 35a.

[0040] Furthermore, the effect of the first inclined surface 35a facing the first side s21 of the second direction d2 in a cross section perpendicular to the first direction d1 will be explained. The solid line labeled L1 in Figure 2 shows an example of the optical path of light incident on the incident surface 11 of the solar cell 10 from diagonally above in the vertical direction. The light can travel through the solar cell 10 along the optical path L1 and reach the first inclined surface 35a. In the example shown in Figure 2, the angle of incidence of the light passing through the optical path L1 to the first inclined surface 35a is angle α1. As a comparative example, consider a solar cell 100 in which the first surface 31 is a plane parallel to the second surface 32. Figure 4 is a cross-sectional view showing the comparative example solar cell 100. In the comparative example solar cell 100, the angle of incidence of the light passing through the optical path L1 to the first surface 31 is angle α2. By having the first inclined surface 35a face the first side s21 of the second direction d2 in a cross-section perpendicular to the first direction d1, the angle α1 can be made larger than the angle α2. In other words, in the solar cell 10 of this embodiment, when light reaches the first inclined surface 35a, the angle of incidence of the light can be made larger than when light reaches the first surface 31 in the comparative example solar cell 100, making total internal reflection more likely to occur.

[0041] Furthermore, in the solar cell 10 of this embodiment, the angle of incidence of light reflected from the first inclined surface 35a to the second surface 32 is angle α3. In the comparative example solar cell 100, the angle of incidence of light reflected from the first surface 31 to the second surface 32 is angle α4. By having the first inclined surface 35a face the first side s21 of the second direction d2 in a cross section perpendicular to the first direction d1, angle α3 can be made larger than angle α4. That is, in the solar cell 10 of this embodiment, when light reflected from the first inclined surface 35a reaches the second surface 32, the angle of incidence of the light can be made larger than when light reflected from the first surface 31 reaches the first surface 31 in the comparative example solar cell 100, making total internal reflection more likely to occur.

[0042] As described above, the first inclined surface 35a makes it easier to cause total internal reflection at the first surface 31 of light incident on the incident surface 11 of the solar cell 10 from a vertically oblique upward direction, and total internal reflection at the second surface 32 of the light reflected from the first surface 31. This makes it possible to lengthen the range (optical path) of light incident on the incident surface 11 of the solar cell 10 from a vertically oblique upward direction within the power generation layer 20.

[0043] In the optical component 30, in order to avoid the formation of a reflective interface between the main body 33 and the prism 35, the refractive index of the main body 33 and the refractive index of the prism 35 may be the same. The main body 33 and the prism 35 may be made of the same material. The main body 33 and the prism 35 may be integrally formed. The material of the optical component 30 may be an organic material, or it may be glass, etc. For example, the material of the optical component 30 may be polycarbonate, polyethylene terephthalate, cycloolefin polymer, acrylic or epoxy, or a mixture of these with a filler made of a high refractive index material. The filler may be an organic filler or an inorganic filler. The filler may also be a metallic filler, or it may be made of a low refractive index material.

[0044] The refractive index is measured using an Abbe refractometer (for example, the "RX-7000α" manufactured by Atago Co., Ltd.). The relative magnitudes of the refractive indices are confirmed by the direction of refraction of light incident on the interface between the materials whose refractive indices are being compared and the conditions for total internal reflection.

[0045] The optical component 30 is transparent. The optical component 30 has a visible light transmittance such that the solar cell 10 transmits visible light as described below. The definition of visible light transmittance in this specification follows the definition in JIS R3106:2019. That is, the visible light transmittance in this specification means the ratio of transmitted light flux to incident light flux in the daylight beam incident parallel to the thickness direction of the object for which the visible light transmittance is to be measured. The visible light transmittance of the optical component 30 is, for example, 80% or more. The visible light transmittance of the optical component 30 may be 90% or more. In this specification, visible light transmittance means the transmittance in the thickness direction d3 of the solar cell 10. The visible light transmittance is determined as the average value of the total light transmittance at each wavelength when measured at 1 nm intervals within the measurement wavelength range of 380 nm to 780 nm using a spectrophotometer. In this case, the spectrophotometer used is the "UV-3600i Plus" manufactured by Shimadzu Corporation (compliant with JIS K0115:2020). For measuring visible light transmittance, a test piece is used which is cut from the optical component 30 into a flat plate shape so that the thickness of the optical component 30 is 1 mm. At this time, the prism portion 35 should not remain on the test piece. The angle of incidence when measuring visible light transmittance is set to 0° unless the transmission direction is specifically defined. The angle of incidence when measuring visible light transmittance is the angle made by the direction of propagation of incident light with respect to the thickness direction d3 of the solar cell 10, and is a value less than 90°.

[0046] The optical component 30 may transmit not only visible light, but also ultraviolet light with a wavelength of 300 nm to 400 nm, and / or infrared light with a wavelength of 750 nm to 1400 nm. Specifically, the optical component 30 may have a transmittance of 80% or more, or 90% or more, for ultraviolet light with a wavelength of 300 nm to 400 nm. The optical component 30 may have a transmittance of 80% or more, or 90% or more, for infrared light with a wavelength of 750 nm to 1400 nm. The thickness of the optical component 30 may be 5 μm or more, or 300 μm or less.

[0047] Next, the power generation layer 20 will be described. The power generation layer 20 is a layer for generating electricity from light entering the solar cell 10. The power generation layer 20 may generate electricity not only from sunlight, but also from illumination light or image light, etc. As an example, the power generation layer 20 is in the form of a thin film. As will be described later, the power generation layer 20 may contain a perovskite-type compound.

[0048] As shown in Figures 1 and 2, the power generation layer 20 is arranged on the substrate 3. In the example shown in Figure 1, the power generation layer 20 has, in order from the incident surface 11 side of the solar cell 10, a second electrode layer 22, a second carrier transport layer 24, a power generation unit 25, a first carrier transport layer 23, and a first electrode layer 21. First, the first electrode layer 21 and the second electrode layer 22 will be described.

[0049] The first electrode layer 21 is a layer for extracting electrons that have moved from the power generation unit 25. The second electrode layer 22 is a layer for extracting holes that have moved from the power generation unit 25. By extracting electrons and holes using the first electrode layer 21 and the second electrode layer 22, the power generated by the power generation unit 25 can be transmitted to the outside. The first electrode layer 21 and the second electrode layer 22 are arranged facing each other. The power generation unit 25 is positioned between the first electrode layer 21 and the second electrode layer 22. The first electrode layer 21 may be a layer for extracting holes that have moved from the power generation unit 25, and the second electrode layer 22 may be a layer for extracting electrons that have moved from the power generation unit 25. Furthermore, in the following description, the first electrode layer 21 will be described as a layer for extracting electrons that have moved from the power generation unit 25, and the second electrode layer 22 will be described as a layer for extracting holes that have moved from the power generation unit 25, with specific numerical values, shapes, and materials shown. In contrast, if the first electrode layer 21 is a layer for extracting holes that have moved from the power generation unit 25, and the second electrode layer 22 is a layer for extracting electrons that have moved from the power generation unit 25, then the specific numerical values, shape, and materials can be changed as appropriate.

[0050] The thickness of the first electrode layer 21 and the thickness of the second electrode layer 22 may be 5 nm or more, or 150 nm or less.

[0051] In this embodiment, the first electrode layer 21 and the second electrode layer 22 have a visible light transmittance such that the solar cell 10 transmits visible light as described later. Specifically, the visible light transmittance of the first electrode layer 21 and the second electrode layer 22 is, for example, 75% or more. The visible light transmittance of the first electrode layer 21 and the second electrode layer 22 may be 85% or more. The first electrode layer 21 and the second electrode layer 22 may have a high visible light transmittance because transparent materials are used. The first electrode layer 21 and the second electrode layer 22 may have a high visible light transmittance because opaque materials are dispersed therein. The first electrode layer 21 and the second electrode layer 22 may be composed of indium tin oxide (ITO), silver nanowires, polythiophene, or a film containing a copper mesh.

[0052] Next, the first carrier transport layer 23 and the second carrier transport layer 24 will be described.

[0053] The first carrier transport layer 23 and the second carrier transport layer 24 are layers for improving the photoelectric conversion efficiency of the power generation layer 20. Specifically, the first carrier transport layer 23 is a layer for efficiently transporting electrons from the power generation unit 25 to the first electrode layer 21. The first carrier transport layer 23 is located between the power generation unit 25 and the first electrode layer 21. The second carrier transport layer 24 is a layer for efficiently transporting holes from the power generation unit 25 to the second electrode layer 22. The second carrier transport layer 24 is located between the power generation unit 25 and the second electrode layer 22.

[0054] In this embodiment, the first carrier transport layer 23 and the second carrier transport layer 24 are transparent. The first carrier transport layer 23 and the second carrier transport layer 24 have a visible light transmittance such that the solar cell 10 transmits visible light as described later. Specifically, the visible light transmittance of the first carrier transport layer 23 and the second carrier transport layer 24 is, for example, 95% or more. The visible light transmittance of the first carrier transport layer 23 and the second carrier transport layer 24 may be 98% or more. The thickness of the first carrier transport layer 23 may be 0.005 μm or more, or 0.120 μm or less. The thickness of the second carrier transport layer 24 may be 0.050 μm or more, or 0.2 μm or less. The material of the first carrier transport layer 23 may be titanium oxide or tin oxide. The material of the second carrier transport layer 24 may be Spiro-OMeTAD or copper thiocyanate.

[0055] Next, the power generation section 25 will be described. The power generation section 25 is a layer that excites electrons and holes inside by absorbing light. Electrons excited in the power generation section 25 move toward the first electrode layer 21. On the other hand, holes excited in the power generation section 25 move toward the second electrode layer 22. Electricity is generated by the movement of electrons and holes in this way. In this manner, the power generation section 25 converts light into electricity. In this embodiment, the power generation section 25 is spread throughout the entire power generation layer 20 when observed from the thickness direction d3.

[0056] For example, the power generation unit 25 contains organic materials.

[0057] As an example, the case where the power generation unit 25 includes a perovskite compound as an organic material will be described. That is, the case where the solar cell 10 is a perovskite solar cell will be described. A perovskite compound refers to a semiconductor compound having a perovskite structure. The perovskite structure usually refers to a crystal structure represented by the composition of AMX3 such as gray titanium stone (CaTiO3; perovskite). The perovskite compound can have various compositions depending on the types of ligands and central metals. In order to increase the photoelectric conversion efficiency, the power generation unit 25 containing the perovskite compound may contain lead. The perovskite compound is, for example, CH3NH3PbI3, CH(NH2)2PbI3, Cs 0.05 (FA 0.85 MA 0.15 ) 0.95 Pb(I 0.89 Br 0.11 )3, Cs 0.1 FA 0.6 MA 0.3 Sn 0.5 Pb 0.5 I3, CsPbCl3 may also be used. The power generation unit 25 may be composed of a high-purity perovskite compound. Specifically, the power generation unit 25 may contain 98% by mass or more of the perovskite compound, and may contain 99% by mass or more.

[0058] The power generation unit 25 containing an organic material may generate electric power by absorbing visible light having a wavelength of 410 nm or more and 700 nm or less, for example. The power generation unit 25 containing an organic material can also generate electric power by light with a lower illuminance than sunlight, for example, illumination light or image light. The power generation unit 25 containing an organic material is more likely to generate electric power by light incident from a direction inclined with respect to the thickness direction d3 as compared with a power generation unit containing an inorganic material such as silicon.

[0059] In the present embodiment, the power generation unit 25 is transparent. The power generation unit 25 has a visible light transmittance such that the solar cell 10 transmits visible light as described later. Specifically, the visible light transmittance of the power generation unit 25 is, for example, 10% or more. The visible light transmittance of the power generation unit 25 may be 30% or more.

[0060] The thickness of the power generation section 25 may be 0.05 μm or more, 100 μm or less, or 0.5 μm or less. The power generation section 25 absorbs light (visible light). Therefore, by making the thickness of the power generation section 25 100 μm or less, the transparency of the power generation layer 20 can be improved. Specifically, the visible light transmittance of the power generation layer 20 can be made 10% or more, as will be described later.

[0061] Such a power generation layer 20 may further include other layers intended to perform specific functions. For example, the power generation layer 20 may further include a protective sheet layer, a filler layer, a strength support layer, an anti-fouling layer, a light containment layer, or an adhesive layer.

[0062] In this embodiment, the power generation layer 20 is transparent. The power generation layer 20 has a visible light transmittance such that the solar cell 10 transmits visible light as described later. The visible light transmittance of the power generation layer 20 is, for example, 10% or more. The visible light transmittance of the power generation layer 20 may be 30% or more.

[0063] The solar cell 10 may further include a layer (not shown) between the optical element 30 and the power generation layer 20 for converting the wavelength of incident light. The solar cell 10 may further include a low-reflection layer (not shown) for suppressing reflection at the incident surface 11. In this case, the low-reflection layer may be provided on the substrate 3 and may constitute the incident surface 11 of the solar cell 10.

[0064] The solar cell 10 of this embodiment transmits visible light. The criteria for determining whether or not the solar cell 10 "transmits visible light" are as follows: Measure the total light transmittance of the solar cell 10. The total light transmittance of the solar cell 10 can be measured using a haze meter (HM-150, manufactured by Murakami Color Technology Laboratory) in accordance with JIS K 7361-1. In measuring the total light transmittance of the solar cell 10, white light is irradiated onto the solar cell 10 at an incident angle of 0°. If the total light transmittance is 10% or more as a result of the measurement, the solar cell 10 is determined to transmit visible light. If the total light transmittance of the solar cell 10 is non-uniform, the solar cell 10 is determined to transmit visible light if the maximum value of the total light transmittance of the solar cell 10 is 10% or more. In this embodiment, the power generation layer 20 is transparent. In this case, the total light transmittance of the solar cell 10 may be 10% or more in 80% or more of the region where the power generation layer 20 is located in a plan view of the solar cell 10.

[0065] If the solar cell 10 transmits visible light according to the above criteria, sunlight, including visible light, can easily penetrate the interior of the solar cell 10 and reach the power generation layer 20. This ease of sunlight reaching the power generation layer 20 allows for efficient utilization of sunlight and increased power generation. Furthermore, if the solar cell 10 transmits visible light according to the above criteria, visible light can easily penetrate the solar cell 10. Therefore, an observer facing the solar cell 10 can see through it to the other side. Additionally, good light collection through the solar cell 10 can be ensured.

[0066] Next, the laminate 1 of this embodiment will be described. Figure 5 is a cross-sectional view showing the laminate 1 and building B of this embodiment. In Figure 5, the internal elements of the solar cell 10 are omitted from the illustration, and the external shape of the solar cell 10 is shown. The laminate 1 comprises the solar cell 10 of this embodiment and a light-transmitting member 1a superimposed on the solar cell 10. As shown in Figure 5, the laminate 1 is fitted into the opening 2 of building B. In the example shown in Figure 5, the laminate 1 is fitted into the opening 2 such that the solar cell 10 is located on the inside side of building B relative to the light-transmitting member 1a. In the example shown in Figure 5, the opening 2 is a window provided in the wall 4 of building B. In the example shown in Figure 5, the incident surface 11 of the solar cell 10 is directed toward the outside side of building B. In the example shown in Figure 5, the incident surface 11 of the solar cell 10 is joined to the surface of the light-transmitting member 1a.

[0067] The light-transmitting member 1a is not particularly limited as long as it is a member that is generally fitted into the window of building B to transmit light and contribute to lighting into the interior of building B. The material of the light-transmitting member 1a is, for example, glass or resin. In the example shown in Figure 5, the light-transmitting member 1a is glass fitted into the opening 2, which is a window. In this case, a laminate 1 comprising the solar cell 10 and the light-transmitting member 1a is formed by attaching the solar cell 10 to the surface of the light-transmitting member 1a, which is glass.

[0068] As shown in Figures 1 and 2, if the solar cell 10 includes a substrate 3 and the surface of the substrate 3 constitutes the incident surface 11 of the solar cell 10, the laminate 1 can be formed by joining the surface of the light-transmitting member 1a to the surface of the substrate 3 that constitutes the incident surface 11. Although not shown, the solar cell 10 provided in the laminate 1 does not necessarily have to include a substrate 3. Even in this case, a laminate 1 can be formed in which the incident surface 11 of the solar cell 10 and the surface of the light-transmitting member 1a are joined. In the laminate 1, at least one of the surfaces of the power generation layer 20 and the circuit 5 constitutes the incident surface 11 of the solar cell 10, and the incident surface 11 and the surface of the light-transmitting member 1a may be joined.

[0069] Next, the building B of this embodiment will be described. In the example shown in Figure 5, building B comprises an opening 2 and a laminated body 1 fitted into the opening 2. In the example shown in Figure 5, the opening 2 is a window provided in the wall 4 of building B. At least one side of building B may be glass-paneled. In this case, the glass-paneled portion of the side of building B can be considered as the opening 2. Furthermore, the glass used for the glass panel can be considered as the light-transmitting member 1a of the laminated body 1. The entire surface of building B may be glass-paneled. Building B may be a building that uses large-area window panes. In this case, the portion that uses large-area window panes can be considered as the opening 2. Furthermore, the large-area window panes can be considered as the light-transmitting member 1a of the laminated body 1.

[0070] In the example shown in Figure 5, the wall 4 extends vertically. As a result, the solar cells 10 contained in the laminate 1 fitted into the opening 2 in the wall 4 are positioned so that their incident surfaces 11 extend vertically. When a plate-like member such as the wall 4 or a surface such as the incident surface 11 "extends vertically," the angle that the plate-like member or surface makes with respect to the vertical may be 30° or less, 20° or less, 10° or less, 5° or less, or 3° or less. In the example shown in Figure 5, the wall 4 is parallel to the vertical. As a result, the solar cells 10 are positioned so that their incident surfaces 11 are parallel to the vertical.

[0071] As shown in Figure 5, when the solar cell 10 is arranged so that its incident surface 11 extends vertically, sunlight is considered to enter the incident surface 11 of the solar cell 10 from a diagonal upward vertical direction. In the solar cell 10 of this embodiment, due to the action of the prism section 35, sunlight that enters the incident surface 11 of the solar cell 10 from a diagonal upward vertical direction and reaches the first surface 31 is more easily reflected into the optical member 30. This makes it possible to lengthen the range (optical path) of sunlight entering the incident surface 11 of the solar cell 10 from a diagonal upward vertical direction within the power generation layer 20. By lengthening the range, sunlight can be utilized more efficiently and the amount of power generated can be increased. Furthermore, an observer facing the solar cell 10 can see the other side of the solar cell 10 through the solar cell 10. By overlaying such a solar cell 10 on a windowpane, it is possible to generate electricity with the solar cell 10 overlaid on the windowpane while allowing the other side of the windowpane to be seen through the windowpane. Furthermore, it is possible to ensure sufficient natural light through the windowpane.

[0072] Next, an example of a manufacturing method for the solar cell 10, the laminate 1, and the building B according to this embodiment will be described.

[0073] First, an optical component 30 having multiple prism sections 35 is prepared. In this case, the optical component 30 may be manufactured by ultraviolet (UV) shaping, casting, or heat shaping. The optical component 30 may also be manufactured by cutting a resin material.

[0074] Next, a first electrode layer 21, a first connection part 6, a first carrier transport layer 23, a power generation part 25, a second carrier transport layer 24, a second electrode layer 22, and a second connection part 7 are provided on the prism portion 35 of the optical member 30.

[0075] The first electrode layer 21, the first connection portion 6, the first carrier transport layer 23, the second carrier transport layer 24, the second electrode layer 22, and the second connection portion 7 may each be formed by vacuum deposition or vacuum film formation such as sputtering. On the other hand, the power generation portion 25 may be manufactured by coating an organic material onto the first carrier transport layer 23. The first connection portion 6 is formed to connect with the first electrode layer 21. The second connection portion 7 is formed to connect with the second electrode layer 22 and the first connection portion 6. The solar cell 10 is manufactured by the above process.

[0076] Next, the solar cell 10 and the light-transmitting member 1a are stacked so that the incident surface 11 of the solar cell 10 and the surface of the light-transmitting member 1a face each other. Subsequently, the incident surface 11 of the solar cell 10 and the surface of the light-transmitting member 1a are joined together. This joining process manufactures the laminate 1.

[0077] Next, the laminated body 1 is fitted into the opening 2. This completes the construction of building B, which includes the laminated body 1.

[0078] As described above, according to this embodiment, the solar cell 10 comprises an optical member 30 having a first surface 31 and a second surface 32 located on the opposite side of the first surface 31, and a power generation layer 20 provided on the second surface 32 side of the optical member 30. The optical member 30 has a plurality of prism portions 35, and at least a part of the first surface 31 is formed by the plurality of prism portions 35. The solar cell 10 transmits visible light. By arranging the solar cell 10 so that the incident surface 11 spreads vertically, the first side s21 is directed upward in the vertical direction, and the second side s22 is directed downward in the vertical direction, the following effects can be obtained: The range (optical path) of sunlight incident on the incident surface 11 of the solar cell 10 from diagonally upward in the vertical direction within the power generation layer 20 can be increased. By increasing the range, sunlight can be utilized efficiently and the amount of power generated can be increased.

[0079] According to this embodiment, each prism portion 35 extends along a first direction d1 and is arranged along a second direction d2 from a first side s21 to a second side s22. Each prism portion 35 includes a first inclined surface 35a facing the first side s21 of the second direction d2 in a cross section perpendicular to the first direction d1, and a second inclined surface 35b facing the second side s22 of the second direction d2 in a cross section perpendicular to the first direction d1. The first inclined surface 35a is larger than the second inclined surface 35b. The first inclined surface 35a makes it easier to cause total internal reflection at the first surface 31 of light incident on the incident surface 11 of the solar cell 10 from diagonally above in the vertical direction, and total internal reflection at the second surface 32 of the light reflected at the first surface 31. This makes it possible to increase the range of light incident on the incident surface 11 of the solar cell 10 from diagonally above in the vertical direction within the power generation layer 20.

[0080] According to this embodiment, the laminate 1 comprises a solar cell 10 and a light-transmitting member 1a superimposed on the solar cell 10. This allows for the ability to see through the laminate 1 to the other side while generating electricity with the solar cell 10 provided on the laminate 1. Furthermore, it ensures light transmission through the laminate 1.

[0081] According to this embodiment, building B comprises an opening 2 and a laminated structure 1 fitted into the opening 2. This allows for visibility through the laminated structure 1 provided in building B, while generating electricity using the solar cells 10 provided in the laminated structure 1. Furthermore, it ensures sufficient natural light through the opening 2.

[0082] <Variation> Next, various modifications of this embodiment will be described with reference to Figures 6 to 9. In Figures 6 to 9, the same reference numerals are used for parts that are the same as those shown in Figures 1 to 3 and Figure 5, and detailed descriptions are omitted.

[0083] <Example 1> The solar cell 10 may be bonded to the first glass substrate 61 of a double-glazed glass 60 comprising a first glass substrate 61 and a second glass substrate 62. In this case, the first glass substrate 61 can be considered as the light-transmitting member 1a described above. Furthermore, the laminate of the solar cell 10 and the first glass substrate 61 can be considered as the laminate 1 described above. The first glass substrate 61 to which the solar cell 10 is bonded may be located on the exterior side of the building on which the double-glazed glass 60 is installed, relative to the second glass substrate 62.

[0084] Figure 6 is a cross-sectional view showing the laminate 1 of the modified example 1. The left side of Figure 6 is the exterior side of the building where the double-glazed glass 60 is installed. The right side of Figure 6 is the interior side of the building where the double-glazed glass 60 is installed. In the example shown in Figure 6, the first glass substrate 61 is located on the exterior side of the building where the double-glazed glass 60 is installed, relative to the second glass substrate 62. The solar cell 10 is bonded to the surface of the first glass substrate 61 that faces the interior side of the building. As a result, the solar cell 10 is located between the first glass substrate 61 and the second glass substrate 62.

[0085] The second glass substrate 62 may have a double-glazed reflective layer 63, as shown in Figure 6. In the example shown in Figure 6, the second glass substrate 62 has a glass substrate body 64 and a double-glazed reflective layer 63 provided on the surface of the glass substrate body 64. The double-glazed reflective layer 63 transmits most of the visible light and reflects at least a portion of the near-infrared light.

[0086] The properties of the double-glazed reflective layer 63 in reflecting near-infrared light are not particularly limited, as long as the reflectance of at least a portion of the near-infrared light on the surface of the second glass substrate 62 is greater than that of the second glass substrate 62 when the double-glazed reflective layer 63 is not present.

[0087] The double-glazed reflective layer 63 is, for example, a Low-E (Low Emissivity) film. In the example shown in Figure 6, the double-glazed reflective layer 63 is provided on the surface of the glass substrate body 64 that faces the interior side of the building.

[0088] The double-glazed reflective layer 63 allows near-infrared light, which is irradiated onto the double-glazed glass from the outside of the building, passes through the laminate 1, and reaches the double-glazed reflective layer 63, to be reflected back towards the power generation layer 20. This increases the range (optical path) of the near-infrared light within the power generation layer 20, allowing for more efficient use of near-infrared light and increased power generation. Furthermore, when it is necessary to maintain a lower temperature inside the building than outside, such as during the summer, the double-glazed reflective layer 63 reduces the amount of near-infrared light reaching the inside of the building, making it easier to maintain a lower temperature inside the building. On the other hand, because the double-glazed reflective layer 63 transmits a large amount of visible light, it is possible to see through the double-glazed glass 60 to the other side of the double-glazed glass 60. In addition, it ensures sufficient natural light through the double-glazed glass 60.

[0089] <Modification 2> The solar cell 10 may further include a corresponding optical member 70 that faces the first surface 31 of the optical member 30 at a distance from it and has a corresponding surface 71 having a shape corresponding to the first surface 31.

[0090] Figure 7 is a cross-sectional view showing a modified example 2 of the solar cell 10 and the laminate 1. The left side of Figure 7 is the exterior side of the building in which the laminate 1 is installed. The right side of Figure 7 is the interior side of the building in which the laminate 1 is installed. In the example shown in Figure 7, the optical member 30 has a plurality of prism portions 35, and at least a portion of the first surface 31 is formed by the plurality of prism portions 35. Each prism portion 35 includes a first inclined surface 35a and a second inclined surface 35b. The corresponding surface 71 of the corresponding optical member 70 includes a first corresponding inclined surface 71a that faces the first inclined surface 35a of the prism portion 35 in the thickness direction d3 and is parallel to the first inclined surface 35a. The corresponding optical member 70 includes a second corresponding inclined surface 71b that faces the second inclined surface 35b of the prism portion 35 in the thickness direction d3 and is parallel to the second inclined surface 35b.

[0091] In the example shown in Figure 7, air is located between the first surface 31 of the optical member 30 and the corresponding surface 71 of the corresponding optical member 70.

[0092] The effects of the corresponding optical element 70 will now be explained. The dashed line labeled L2 in Figure 7 shows an example of the optical path of light entering the solar cell 10 from the incident surface 11 and reaching the first inclined surface 35a, assuming the solar cell 10 shown in Figure 7 does not have the corresponding optical element 70. The solid line labeled L3 in Figure 7 shows an example of the optical path of light entering the solar cell 10 from the incident surface 11 and reaching the first inclined surface 35a, assuming the solar cell 10 is equipped with the corresponding optical element 70. As shown in Figure 7, the light that reaches the first inclined surface 35a is refracted at the first inclined surface 35a. Therefore, if the solar cell 10 does not have the corresponding optical element 70, the direction of propagation of light entering the solar cell 10 from the incident surface 11 and the direction of propagation of light emitted from the surface opposite to the incident surface 11 of the solar cell 10 will be different. As a result, when an observer looks at the other side of the solar cell 10 through the solar cell 10, the landscape that is seen may be significantly shifted in position from the original landscape.

[0093] In contrast, when the solar cell 10 is equipped with a corresponding optical element 70, the light refracted at the first inclined surface 35a enters the first corresponding inclined surface 71a and is refracted again. Similarly, when the solar cell 10 is equipped with a corresponding optical element 70, the light that enters the solar cell 10 from the incident surface 11 and is refracted at the second inclined surface 35b enters the second corresponding inclined surface 71b and is refracted again. Due to these actions, when the solar cell 10 is equipped with a corresponding optical element 70, the direction of propagation of light entering the solar cell 10 from the incident surface 11 and the direction of propagation of light emitted from the surface of the solar cell 10 opposite to the incident surface 11 become parallel. This reduces the positional discrepancy between the visible scenery and the actual scenery when an observer views the other side of the solar cell 10 through the solar cell 10. The shape of the corresponding surface 71 is determined such that the direction of light entering the solar cell 10 from the incident surface 11 is parallel to the direction of light emitted from the surface opposite to the incident surface 11 of the solar cell 10, as the light refracted at the first surface 31 is refracted again at the corresponding surface 71.

[0094] The material of the corresponding optical component 70 is, for example, the same as the material of the optical component 30 described above. The method for manufacturing the corresponding optical component 70 is, for example, the same as the method for manufacturing the optical component 30 described above.

[0095] The solar cell 10 may further include a holding member that maintains a constant distance between the first surface 31 of the optical member 30 and the corresponding surface 71 of the corresponding optical member 70. In the example shown in Figure 7, the incident surface 11 of the solar cell 10 is bonded to the surface of the first glass substrate 61 of the double-glazed glass 60 that faces the inside of the building. The surface of the corresponding optical member 70 that is opposite to the corresponding surface 71 is bonded to the surface of the second glass substrate 62 of the double-glazed glass 60 that faces the outside of the building. This maintains a constant distance between the first surface 31 of the optical member 30, which is fixed to the substrate 3 that constitutes the incident surface 11 via the power generation layer 20, and the corresponding surface 71 of the corresponding optical member 70. In this case, the second glass substrate 62 can be considered as the holding member described above. In Figure 7, the internal elements of the second glass substrate 62 are omitted from the illustration, and the external shape of the second glass substrate 62 is shown.

[0096] <Variation 3> The solar cell 10 may further include a reflective layer 40 provided on the second inclined surface 35b of each prism portion 35.

[0097] Figure 8 is a cross-sectional view showing a modified example 3 of the solar cell 10. The optical member 30 of the solar cell 10 shown in Figure 8 has a plurality of prism portions 35, and at least a portion of the first surface 31 is formed by the plurality of prism portions 35. Each prism portion 35 includes a first inclined surface 35a and a second inclined surface 35b. The reflective layer 40 is provided on the second inclined surface 35b of each prism portion 35, but not on the first inclined surface 35a.

[0098] The reflective layer 40 reflects light, including visible light. The reflective layer 40 may reflect a large amount of visible light and near-infrared light. The material of the reflective layer 40 is not particularly limited, as long as it increases the reflectivity on the second inclined surface 35b of light, including visible light, that travels through the optical member 30 and reaches the second inclined surface 35b compared to when the reflective layer 40 is not provided on the second inclined surface 35b. The reflective layer 40 is, for example, a metal layer or a metal oxide layer that does not transmit visible light. The material of the reflective layer 40 may be, for example, a metal material such as aluminum, indium, or tin, or zinc oxide (ZnO), titanium oxide (TiO2), zinc sulfide, or aluminum oxide.

[0099] The effect of the reflective layer 40 will now be explained. The solid line labeled L4 in Figure 8 shows an example of the optical path of light that enters the solar cell 10 from the incident surface 11 and reaches the second inclined surface 35b. In the solar cell 10 shown in Figure 8, the light that reaches the second inclined surface 35b is reflected by the reflective layer 40. In the example of optical path L4, the light that reaches the second inclined surface 35b is reflected by the reflective layer 40, then reflected again by the first inclined surface 35a, and heads back towards the power generation layer 20. This increases the range (optical path) of the light within the power generation layer 20, allowing for more efficient use of light and increased power generation.

[0100] In particular, consider the case where the solar cell 10 of Modification 4 is arranged such that the incident surface 11 extends vertically, the first side s21 is directed upward in the vertical direction, and the second side s22 is directed downward in the vertical direction. In this case, it is thought that some of the sunlight incident on the incident surface 11 of the solar cell 10 from diagonally upward in the vertical direction reaches the second inclined surface 35b. The reflective layer 40 can reflect the sunlight that reaches the second inclined surface 35b, including visible light, and direct it back towards the power generation layer 20. This makes it possible to efficiently utilize sunlight, including visible light, and increase the amount of power generated.

[0101] On the other hand, an observer facing the solar cell 10 can see the other side of the solar cell 10 through the first inclined surface 35a, which is larger than the second inclined surface 35b. In the modified example 3, from the viewpoint of making it less likely for the reflective layer 40 to obstruct the observer's line of sight when the observer sees the other side of the solar cell 10 through the solar cell 10, it is preferable that the angle θ2 between the second surface 32 and the second inclined surface 35b is close to 90°. The angle θ2 may be 90°.

[0102] <Modification 4> The solar cell 10 may further include a wavelength-selective reflective layer 50 provided on the first surface 31 of the optical member 30. In this case, the wavelength-selective reflective layer 50 may be provided on at least the first inclined surface 35a.

[0103] Figure 9 is a cross-sectional view showing a modified example 4 of the solar cell 10. The optical member 30 of the solar cell 10 shown in Figure 9 has a plurality of prism portions 35, and at least a portion of the first surface 31 is formed by the plurality of prism portions 35. Each prism portion 35 includes a first inclined surface 35a and a second inclined surface 35b. In the example shown in Figure 9, the wavelength selective reflective layer 50 is provided on the first inclined surface 35a and the second inclined surface 35b. In the example shown in Figure 9, the wavelength selective reflective layer 50 covers the entire first surface 31.

[0104] The wavelength-selective reflective layer 50 selectively reflects light containing wavelengths that the power generation layer 20 can use to generate electricity. On the other hand, the wavelength-selective reflective layer 50 has a visible light transmittance such that the solar cell 10 transmits visible light as described above.

[0105] The visible light transmittance of the wavelength-selective reflective layer 50 is, for example, 40% or more.

[0106] The characteristic of the wavelength-selective reflective layer 50 to selectively reflect light is not particularly limited, as long as the reflectance on the first surface 31 of light containing wavelengths that the power generation layer 20 can use to generate power is greater than in the case where the wavelength-selective reflective layer 50 is not provided on the first surface 31. If the power generation layer 20 can use near-infrared light to generate power, the wavelength-selective reflective layer 50 may selectively reflect near-infrared light.

[0107] The material of the wavelength-selective reflective layer 50 may be the same as the material of the double-glazed reflective layer 63 described above. The wavelength-selective reflective layer 50 may also be a Low-E film.

[0108] The effect of the wavelength-selective reflective layer 50 will now be explained. The solid line labeled L5 in Figure 9 shows an example of the optical path of light of a wavelength reflected by the wavelength-selective reflective layer 50 after it enters the solar cell 10 from the incident surface 11 and reaches the first surface 31, particularly the first inclined surface 35a. In the solar cell 10 shown in Figure 9, the light of a wavelength reflected by the wavelength-selective reflective layer 50 that reaches the first surface 31 is reflected by the wavelength-selective reflective layer 50 and heads back towards the power generation layer 20. This increases the range (optical path) of the light of a wavelength reflected by the wavelength-selective reflective layer 50 within the power generation layer 20, allowing for more efficient use of light and increased power generation.

[0109] In particular, in the example of optical path L5, light reaches the first inclined surface 35a, is reflected by the first inclined surface 35a, and then reaches the second surface 32. At this time, the action of the first inclined surface 35a increases the incident angle α3 of the light reflected by the first inclined surface 35a onto the second surface 32, making total internal reflection more likely. In particular, as shown in Figure 9, the incident angle α3 becomes even larger than the incident angle α1 of the light onto the first inclined surface 35a. Therefore, by providing the wavelength-selective reflective layer 50 on the first inclined surface 35a, more light with a large incident angle α3 can reach the second surface 32, and more light can be totally reflected by the second surface 32 and directed towards the power generation layer 20. As a result, the amount of power generated can be increased by utilizing light particularly efficiently.

[0110] Furthermore, the wavelength-selective reflective layer 50 selectively reflects light, and the solar cell 10 has a visible light transmittance sufficient to transmit visible light as described above, so that an observer facing the solar cell 10 can see through it to the other side. In addition, light collection through the solar cell 10 can be ensured.

[0111] <Modification 5> In the embodiments and modifications described above, an example was given in which the power generation unit 25 is spread throughout the entire power generation layer 20 when observed from the thickness direction d3. However, the form of the power generation unit 25 is not limited to this. The power generation unit 25 does not have to be spread throughout the entire power generation layer 20 when observed from the thickness direction d3. The power generation unit 25 may be dispersed within the region occupied by the power generation layer 20 when observed from the thickness direction d3. In this case, a filler material that does not contribute to power generation may be filled between the dispersed power generation units 25. In this case, the dispersed power generation units 25 may not be transparent, and the filler material may be transparent. Even if the dispersed power generation units 25 are not transparent, the transparency of the filler material can sufficiently increase the overall visible light transmittance of the power generation units 25. This makes the solar cell 10 transparent to visible light. In the case where the power generation units 25 are dispersed and not transparent, as in Modification 5, the solar cell 10 may be a silicon solar cell. As in Modification 5, if the power generation units 25 are dispersed and the power generation units 25 are not transparent, the total light transmittance of the solar cell 10 may be 10% or more in 80% or more of the region in a plan view of the solar cell 10 where the power generation layer 20 is located and the power generation units 25 are not located.

[0112] The multiple components disclosed in the above embodiments and each of the variations can be combined as needed. Alternatively, some components may be removed from all the components shown in the above embodiments and each of the variations. [Explanation of symbols]

[0113] 1. Laminate 1a Translucent member 2 openings 3 circuit boards 5 circuits 6. First connection section 7. Second connection section 10 Solar Cells 11 Entrance plane 20 Power generation layer 21 1st electrode layer 22 Second electrode layer 23. First Carrier Transport Layer 24. Second Carrier Transport Layer 25 Power Generation Department 30 Optical components 31 Page 1 32 2nd page 33 Main body 35 Prism section 35a 1st slope 35b 2nd slope 40 reflective layer 50 wavelength selective reflective layer 70 Compatible Optical Components B Building

Claims

1. An optical member having a first surface and a second surface located opposite the first surface, The optical member comprises a power generation layer provided on the second surface side, A solar cell that transmits visible light, wherein the optical element has a plurality of prism portions, and at least a portion of the first surface is formed by the plurality of prism portions.

2. The solar cell according to claim 1, further comprising a corresponding optical member having a corresponding surface that is spaced apart from the first surface of the optical member and has a corresponding shape corresponding to the first surface.

3. Each of the prism portions extends along a first direction parallel to the second surface and is arranged from the first side to the second side along a second direction that is parallel to the second surface and perpendicular to the first direction. Each of the prism portions includes a first inclined surface facing the first side of the second direction in a cross section perpendicular to the first direction, and a second inclined surface facing the second side of the second direction in a cross section perpendicular to the first direction. The solar cell according to claim 2, wherein the first inclined surface is larger than the second inclined surface.

4. The solar cell according to claim 3, further comprising a reflective layer provided on the second inclined surface of each of the prism portions.

5. The solar cell according to claim 1, further comprising a wavelength-selective reflective layer provided on the first surface of the optical member, which selectively reflects light containing wavelengths that the power generation layer can use to generate electricity.

6. Each of the prism portions extends along a first direction parallel to the second surface and is arranged from the first side to the second side along a second direction that is parallel to the second surface and perpendicular to the first direction. Each of the prism portions includes a first inclined surface facing the first side of the first direction in a cross section perpendicular to the first direction, and a second inclined surface facing the second side of the first direction in a cross section perpendicular to the first direction. The first inclined surface is larger than the second inclined surface. The solar cell according to claim 5, wherein the wavelength-selective reflective layer is provided on at least the first inclined surface.

7. A solar cell according to any one of claims 1 to 6, A laminate that is fitted into an opening in a building, comprising a light-transmitting member superimposed on the aforementioned solar cell.

8. The opening and A building comprising a laminate according to claim 7 fitted into the aforementioned opening.

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