Optical member and organic solar cell with attached optical member

Abstract

An optical member (30) is superimposed on an organic solar cell (20). The optical member (30) includes a base material (31) and a resin layer (33) provided to the base material (31). The resin layer (33) includes a plurality of unit elements (33a) two-dimensionally arranged in a plan view of the optical member (30) so as to form a pattern of recesses and protrusions. In a plan view of the optical member (30), the average distance between the centers of gravity (Dc) of two adjacent unit elements (33a) is 0.5 μm or more and 30 μm or less. In a cross section of the optical member (30), the maximum depth (Dmax) of the unit element (33a) is 0.1 μm or more and 3.6 μm or less.

Description

Optical components, organic solar cells with optical components

[0001] The present disclosure relates to an optical member and an organic solar cell with an optical member.

[0002] Photovoltaic power generation is known as a power generation method that places little strain on the environment. Solar cells are used for photovoltaic power generation. Solar cells convert light into electricity. There are inorganic solar cells and organic solar cells. Organic solar cells have the advantage of low manufacturing costs.

[0003] International Publication No. 2021 / 241542

[0004] Conventional organic solar cells cannot be said to be efficient at converting irradiated light into electricity. The present disclosure aims to improve the efficiency at which organic solar cells convert irradiated light into electricity.

[0005] The optical element of the present disclosure is an optical element to be overlaid on an organic solar cell, and comprises: a substrate; and a resin layer provided on the substrate; the resin layer includes a plurality of unit elements that are two-dimensionally arranged in a planar view of the optical element so as to form a concave-convex pattern; the average distance between the centers of gravity of two adjacent unit elements in a planar view of the optical element is 0.5 μm or more and 30 μm or less; and the maximum depth of the unit elements in a cross section of the optical element is 0.1 μm or more and 3.6 μm or less.

[0006] According to the present disclosure, it is possible to improve the efficiency of converting light irradiated onto an organic solar cell into electricity.

[0007] FIG. 1 is a plan view of a solar photovoltaic power generation system according to an embodiment of the present disclosure. FIG. 2A is a cross-sectional view of an organic solar cell with an optical member according to an embodiment, taken along a line corresponding to line II-II in FIG. 1 . FIG. 2B is a cross-sectional view showing another example of an organic solar cell with an optical member according to an embodiment, taken along a line corresponding to line II-II in FIG. 1 . FIG. 3 is a cross-sectional view of an organic solar cell. FIG. 4A is an enlarged cross-sectional view of an optical member. FIG. 4B is a cross-sectional view of an organic solar cell with an optical member according to an embodiment. FIG. 4C is a cross-sectional view of an organic solar cell with an optical member according to an embodiment. FIG. 4D is an enlarged cross-sectional view of an example of a low-reflection layer and a resin layer of an optical member. FIG. 4E is an enlarged cross-sectional view of an example of a low-reflection layer and a resin layer of an optical member. FIG. 5 is a plan view of an example of a unit element in a resin layer. FIG. 6 is a plan view of an example of a unit element in a resin layer. FIG. 7 is a plan view of an example of a unit element in a resin layer. FIG. 8 is a plan view of an example of a unit element in a resin layer. FIG. 9 is a plan view of an example of a unit element in a resin layer. Fig. 10 is a plan view of an example of a unit element in a resin layer. Fig. 11 is a graph showing the measurement results of short-circuit current of organic solar cells with optical members according to examples and comparative examples.

[0008] In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of ease of illustration and understanding. Components shown in some drawings may be omitted in other drawings.

[0009] In this specification, terms such as "parallel," "orthogonal," and "identical," which specify shapes and geometric conditions and their degrees, as well as values ​​of lengths and angles, are not limited to their strict meanings but are interpreted to include a range of degrees within which similar functions can be expected.

[0010] In this specification, the normal direction of a sheet-like member refers to the normal direction to the sheet surface of the target sheet-like member. Also, the "sheet surface" refers to the surface that coincides with the target sheet-like member when the target sheet-like member is viewed overall and in a global perspective.

[0011] In this specification, when multiple upper limit value candidates and multiple lower limit value candidates are listed for a parameter, the parameter may be a numerical range that combines any one upper limit value candidate and any one lower limit value candidate.

[0012] An embodiment of the present disclosure relates to the following [1] to [8]. [1] An optical element to be overlaid on an organic solar cell, comprising: a substrate; and a resin layer provided on the substrate, wherein the resin layer includes a plurality of unit elements that are two-dimensionally arranged in a plan view of the optical element so as to form a concave-convex pattern, wherein the average distance between the centers of gravity of two adjacent unit elements in a plan view of the optical element is 0.5 μm or more and 30 μm or less, and the maximum depth of the unit elements in a cross section of the optical element is 0.1 μm or more and 3.6 μm or less. [2] The optical element according to [1], wherein the haze value of the optical element is 1% or more and 60% or less. [3] The optical element according to [1] or [2], wherein the radius of curvature of the surface of the unit elements in a cross section of the optical element is 1 μm or more and 300 μm or less. [4] The optical member according to any one of [1] to [3], wherein the unit elements have a polygonal, circular, or elliptical shape in a plan view of the optical member. [5] An organic solar cell with an optical member, comprising: the optical member according to any one of [1] to [4]; and an organic solar cell on which the optical member is overlaid. [6] An organic solar cell with an optical member, comprising: an optical member having a base and a resin layer provided on the base, the resin layer including a plurality of unit elements arranged to form a concave-convex pattern, the organic solar cell having at least a photoelectric conversion layer, and a light collecting position of the optical member being located on a surface of the photoelectric conversion layer facing the optical member. [7] An organic solar cell with an optical member, comprising: an optical member; and an organic solar cell having the optical member overlaid thereon; wherein the optical member has, in a first direction, a base material and a resin layer provided on the base material, in this order; the resin layer includes a plurality of unit elements arranged to form a concave-convex pattern; the organic solar cell has at least a photoelectric conversion layer; and the light collection position of the optical member is located within the photoelectric conversion layer in the first direction.[8] An organic solar cell comprising an optical element and an organic solar cell having the optical element stacked thereon, wherein the optical element has, in a first direction, a substrate and a resin layer provided on the substrate, in this order, and the resin layer includes a plurality of unit elements arranged to form a concave-convex pattern, and the organic solar cell has at least a photoelectric conversion layer, and X layers (X is a natural number of 1 or more) are provided between the unit elements and the photoelectric conversion layer, wherein the radius of curvature of the unit elements is R, the length in the first direction of an Mth layer (M is a natural number of 1 or more and X or less) from the unit element in the first direction is d(M+1), the refractive index of the unit elements is N1, and the refractive index of the Mth layer from the unit element in the first direction is N(M+1). The distance D from the unit element to the photoelectric conversion layer in the first direction satisfies the following relationship: An organic solar cell with optical components that satisfies the above relationship.

[0013] An embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 is a plan view of a solar power generation system according to the embodiment. The solar power generation system 1 supplies electric power when irradiated with light. The solar power generation system 1 converts light energy into electrical energy. The solar power generation system 1 supplies electric power not only from sunlight but also from illumination light, image light, and the like. As shown in FIG. 1 , the solar power generation system 1 includes a substrate 3, a circuit 5, and a plurality of organic solar cells 10 with optical components. The solar power generation system 1 supplies electric power generated when the organic solar cells 10 with optical components are irradiated with light via the circuit 5 to a power consuming device (not shown) and a storage battery (not shown) for storing the electric power.

[0014] The substrate 3 supports the circuit 5 and the organic solar cell 10 with an optical member. The substrate 3 is plate-shaped. 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 an insulator. The material of the substrate 3 may be an inorganic material such as glass, a plastic material such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cycloolefin polymer, or polyimide, or a composite material such as a nanocomposite.

[0015] The circuit 5 electrically connects two organic solar cells 10 with an optical member, or connects the organic solar cell 10 with a power consuming device or a storage battery that stores power (not shown). Between the two organic solar cells 10 with an optical member, the circuit 5 includes a first connection portion 6 and a second connection portion 7. The first connection portion 6 and the second connection portion 7 are connected to each other. The first connection portion 6 is connected to a first electrode layer 21 (described below) of the organic solar cell 10 with an optical member. The second connection portion 7 is connected to a second electrode layer 22 (described below) of the organic solar cell 10 with an optical member. The first connection portion 6 and the second connection portion 7 connect adjacent organic solar cells 10 with an optical member. Power generated in the organic solar cell 10 with an optical member is transmitted via the circuit 5. The circuit 5 is made of a conductive material such as copper.

[0016] In the example shown in FIG. 1 , a plurality of organic solar cells 10 with an optical member are regularly arranged two-dimensionally. FIG. 2A is a cross-sectional view of the organic solar cell 10 with an optical member, taken along a line corresponding to line II-II in FIG. 1 . As shown in FIG. 2A , the organic solar cell 10 with an optical member includes a first surface 11 and a second surface 12 opposite to the first surface 11. The first surface 11 and the second surface 12 form a pair of plate surfaces of the organic solar cell 10 with an optical member. The first surface 11 forms the surface of the organic solar cell 10 with an optical member. The organic solar cell 10 with an optical member is in contact with the substrate 3 at the second surface 12. The organic solar cell 10 with an optical member includes, in this order from the first surface 11 to the second surface 12.

[0017] The refractive index adjustment layer 15 prevents the formation of an interface with a large refractive index difference between the organic solar cell 20 and the optical member 30. The refractive index of the refractive index adjustment layer 15 is between the refractive index of the portion of the organic solar cell 20 closest to the optical member 30 and the refractive index of the portion of the optical member 30 closest to the organic solar cell 20. The refractive index adjustment layer 15 is in the form of a thin film. The thickness of the refractive index adjustment layer 15 may be 0.005 μm or more or 20 μm or less. The material of the refractive index adjustment layer 15 may be an acrylic or silicone-based optical clear adhesive (OCA). In the organic solar cell 10 with an optical member, the refractive index adjustment layer 15 may be omitted.

[0018] The refractive index values ​​are measured using an Abbe refractometer (for example, the RX-7000α manufactured by Atago Co., Ltd.) The magnitude relationship between the refractive indices is confirmed based on the refraction direction of light incident on the interface between the members whose refractive indices are being compared and the total reflection conditions.

[0019] The organic solar cells 20 generate electricity using light transmitted through the optical member 30. The organic solar cells 20 can generate electricity not only from sunlight but also from illumination light, image light, and the like. In the example shown in FIG. 1 , ten organic solar cells 20 are connected in series. The organic solar cells 20 are thin-film solar cells. The organic solar cells 20 may be organic thin-film solar cells. The organic solar cells 20 may be perovskite solar cells. When the organic solar cells 20 are perovskite solar cells, the optical interaction between the perovskite compound structure of the photoelectric conversion layer 25 (described below) and the optical member 30 is considered to be particularly effective in improving the efficiency of the optical member 30, as described below, in converting light incident on the organic solar cells 20 into electricity. The thickness of the organic solar cells 20 may be 0.05 μm or more, 100 μm or less, or 0.5 μm or less. The organic solar cells 20 may be transparent. The visible light transmittance of the organic solar cells 20 may be 10% or more, or 30% or more. FIG. 3 shows a cross-sectional view of an organic solar cell 20. The organic solar cell 20 has at least a photoelectric conversion layer 25. As shown in FIG. 3, the organic solar cell 20 includes, in a first direction D1, a first barrier layer 27, a first electrode layer 21, a first carrier transport layer 23, a photoelectric conversion layer 25, a second carrier transport layer 24, a second electrode layer 22, and a second barrier layer 28, in this order. The first surface 11 of the organic solar cell 10 with an optical member is closer to the second barrier layer 28 than the first barrier layer 27. The second surface 12 of the organic solar cell 10 with an optical member is closer to the first barrier layer 27 than the second barrier layer 28. The first barrier layer 27 forms the second surface 12 of the organic solar cell 10 with an optical member.

[0020] In this specification, visible light transmittance is specified as the average value of the total light transmittance at each wavelength when measured in 1 nm increments within a wavelength range of 380 nm to 780 nm using a spectrophotometer (Shimadzu Corporation's "UV-3600i Plus," compliant with JIS K0115). The angle of incidence when measuring visible light transmittance is set to 0° unless a particular transmission direction is specified. The angle of incidence is the angle between the normal to the incident surface and the traveling direction of incident light, and is a value less than 90°.

[0021] The photoelectric conversion layer 25 absorbs light to excite electrons and holes therein. The excited electrons move toward the first electrode layer 21. The excited holes move toward the second electrode layer 22. The movement of electrons and holes generates electricity. In this way, the photoelectric conversion layer 25 converts light into electricity. The photoelectric conversion layer 25 contains an organic material. The photoelectric conversion layer 25 may contain a perovskite compound. A perovskite compound refers to a semiconductor compound having a perovskite structure. A perovskite structure is usually formed by perovskite (CaTiO ３ AMX such as perovskite ３ The perovskite compound has a crystal structure represented by the following composition. The perovskite compound can have various compositions depending on the type of ligand and central metal. The photoelectric conversion layer 25 containing the perovskite compound contains lead to increase the photoelectric conversion efficiency. The perovskite compound is, for example, CH ３ NH ３ PbI ３ , CH(NH ２ ) ２ PbI ３ , 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 I ３ , CsPbCl ３The photoelectric conversion layer 25 may be made of a high-purity perovskite compound. Specifically, the photoelectric conversion layer 25 may contain 98% by mass or more, or 99% by mass or more, of the perovskite compound. The photoelectric conversion layer 25 containing an organic material can generate electricity by absorbing visible light having a wavelength of 410 nm or more and 700 nm or less, for example. The photoelectric conversion layer 25 containing an organic material can also generate electricity using light with lower illuminance than sunlight, such as illumination light or image light. Compared to a photoelectric conversion layer containing an inorganic material such as silicon, the photoelectric conversion layer 25 containing an organic material is more likely to generate electricity even using light from a direction oblique to the normal direction of the photoelectric conversion layer 25. Furthermore, the photoelectric conversion layer 25 may be a single layer made of CIGS, GaAs, CdTe, or amorphous silicon (a-Si), a laminated layer of these, or a tandem layer of these layers and c-Si. The photoelectric conversion layer 25 may be transparent. Specifically, the visible light transmittance of the photoelectric conversion layer 25 may be 10% or more, or 30% or more. The thickness of the photoelectric conversion layer 25 may be 0.05 μm or more, 100 μm or less, or 0.5 μm or less.

[0022] The first carrier transport layer 23 is disposed between the photoelectric conversion layer 25 and the first electrode layer 21. The first carrier transport layer 23 efficiently transports electrons from the photoelectric conversion layer 25 to the first electrode layer 21. The second carrier transport layer 24 is disposed between the photoelectric conversion layer 25 and the second electrode layer 22. The second carrier transport layer 24 efficiently transports holes from the photoelectric conversion layer 25 to the second electrode layer 22. The first carrier transport layer 23 and the second carrier transport layer 24 improve the photoelectric conversion efficiency of the organic solar cell 20. The first carrier transport layer 23 and the second carrier transport layer 24 may be transparent. Specifically, the visible light transmittance of the first carrier transport layer 23 and the second carrier transport layer 24 may be 95% or more, or 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.

[0023] The first electrode layer 21 extracts electrons that have migrated from the photoelectric conversion layer 25. The second electrode layer 22 extracts holes that have migrated from the photoelectric conversion layer 25. By extracting electrons and holes using the first electrode layer 21 and the second electrode layer 22, power generated in the photoelectric conversion layer 25 can be transmitted to the outside. The first electrode layer 21 and the second electrode layer 22 are arranged opposite each other. The photoelectric conversion layer 25 is arranged between the first electrode layer 21 and the second electrode layer 22. The first electrode layer 21 and the second electrode layer 22 may be transparent. Specifically, the visible light transmittance of the first electrode layer 21 and the second electrode layer 22 may be 75% or more, or 85% or more. The thickness of the first electrode layer 21 and the second electrode layer 22 may be 5 nm or more, or 150 nm or less. The material of the first electrode layer 21 and the second electrode layer 22 may be indium tin oxide (ITO), silver nanowires, polythiophene, or a film including a mesh made of copper.

[0024] The first barrier layer 27 and the second barrier layer 28 block oxygen and water vapor to protect the photoelectric conversion layer 25 from oxygen and water vapor. The first barrier layer 27 and the second barrier layer 28 have water vapor barrier properties and oxygen barrier properties. Specifically, the water vapor permeability of the first barrier layer 27 and the second barrier layer 28 is 0.5 g / m ２ ・It may be 0.1 g / m or less. ２ The oxygen permeability of the first barrier layer 27 and the second barrier layer 28 may be 10 cc / m or less. ２ ・day・atm or less, 5cc / m ２ Water vapor permeability [g / m ２ ·day] is a value measured in accordance with JIS K7129B. The water vapor permeability is measured using a water vapor permeability measuring instrument (PERMATRAN manufactured by MOCON) under an environment of a temperature of 40°C and a humidity of 90% RH. Oxygen permeability [cc / m ２ ·day·atm] is a value measured in accordance with JIS K7126-1. The oxygen permeability is measured using an oxygen permeability measuring device (OXTRAN manufactured by MOCON) in an environment of a temperature of 23°C and a humidity of 90% RH. The first barrier layer 27 and the second barrier layer 28 may be transparent. Specifically, the visible light transmittance of the first barrier layer 27 and the second barrier layer 28 may be 85% or more, or 95% or more. The first barrier layer 27 and the second barrier layer 28 are thin films. The thickness of the first barrier layer 27 and the second barrier layer 28 may be 5 nm or more, or 80 nm or less. The material of the first barrier layer 27 and the second barrier layer 28 may be silicon oxide, aluminum oxide, or silicon nitride.

[0025] The organic solar cell 20 may further include other layers intended to perform specific functions, such as a filler layer, a strength support layer, a light confinement layer, and an adhesive layer.

[0026] The optical member 30 exhibits an optical function to improve the amount of power generated by the organic solar cells 20 using light. The optical member 30 is overlaid on the organic solar cells 20. The optical member 30 is sheet-shaped. The thickness of the optical member 30 may be 5 μm or more or 188 μm or less. The optical member 30 may be transparent. Specifically, the visible light transmittance of the optical member 30 may be 84% or more or 92% or more. In the example shown in FIG. 2A , the optical member 30 is independently provided so as to overlay each organic solar cell 20. In this case, the optical member 30 is not provided between the organic solar cells 20. In the example shown in FIG. 2A , the weight of the organic solar cell 10 with the optical member can be reduced. The example shown in FIG. 2A is not limited to the example shown in FIG. 2A , but the optical member 30 may be provided so as to overlay multiple organic solar cells 20, as shown in FIG. 2B . Such an optical member 30 can be provided without alignment with the multiple organic solar cells 20. Furthermore, the surface of the organic solar cell 10 with an optical member can be flattened. Fig. 4A shows a cross-sectional view of the optical member 30. As shown in Fig. 4A, the optical member 30 includes, in the first direction D1, a surface layer 35, a low-reflection layer 34, a resin layer 33, an easy-adhesion layer 32, a base material 31, and a bonding layer 37, in this order. The first surface 11 of the organic solar cell 10 with an optical member is closer to the surface layer 35 than to the bonding layer 37. The second surface 12 of the organic solar cell 10 with an optical member is closer to the bonding layer 37 than to the surface layer 35. The surface layer 35 forms the first surface 11 of the organic solar cell 10 with an optical member.

[0027] The substrate 31 supports the other components of the optical member 30. The substrate 31 is thin and may be transparent. Specifically, the visible light transmittance of the substrate 31 may be 85% or more, or 95% or more. The thickness of the substrate 31 may be 5 μm or more, or 300 μm or less. The material of the substrate 31 may be triacetyl cellulose, polyethylene terephthalate, cycloolefin polymer, or acrylic.

[0028] The easy-adhesion layer 32 improves the adhesion between the substrate 31 and the resin layer 33. The easy-adhesion layer 32 is located between the substrate 31 and the resin layer 33. The easy-adhesion layer 32 is in the form of a thin film. The thickness of the easy-adhesion layer 32 is, for example, 0.1 μm or more and 10 μm or less. The easy-adhesion layer 32 is made of, for example, a urethane resin. In the optical member 30, the easy-adhesion layer 32 may be omitted.

[0029] The resin layer 33 exerts an optical effect on the light passing through it due to its shape. The optical effect of the resin layer 33 can improve the efficiency of converting light irradiated onto the organic solar cell 20 into electricity. The resin layer 33 has a concave-convex pattern formed on its surface. The resin layer 33 includes a plurality of unit elements 33a arranged to form the concave-convex pattern. In the present embodiment, the resin layer 33 includes a plurality of unit elements 33a arranged two-dimensionally in a plan view of the optical member 30 to form the concave-convex pattern. In the example shown in FIG. 4A , the unit elements 33a form a convex shape, and a concave shape is formed between adjacent unit elements 33a. The unit elements 33a being two-dimensionally arranged means that the unit elements 33a are arranged in two or more directions.

[0030] 4B , the light collection position P of the optical member 30 is located on the surface of the photoelectric conversion layer 25 of the organic solar cell 20 that faces the optical member 30. This can further improve the efficiency of converting light irradiated onto the organic solar cell 20 into electricity.

[0031] Here, X layers (X is a natural number of 1 or more) may be provided between the unit element 33a and the photoelectric conversion layer 25. In this case, the length in the first direction D1 of the Mth layer (M is a natural number of 1 or more and X or less) from the unit element 33a in the first direction D1 is defined as d(M+1). Furthermore, the refractive index of the unit element 33a is defined as N1, and the refractive index of the Mth layer from the unit element 33a in the first direction D1 is defined as N(M+1). In this case, the radius of curvature R of the unit element 33a is defined as The following relationship is satisfied.

[0032] The distance D from the unit element 33a to the photoelectric conversion layer 25 in the first direction D1 is The following relationship is satisfied.

[0033] In the present embodiment, seven layers are provided between the unit element 33 a and the photoelectric conversion layer 25. That is, in the example shown in Fig. 4B , a resin layer 33, an easy-adhesion layer 32, a base material 31, a bonding layer 37, a second barrier layer 28, a second electrode layer 22, and a second carrier transport layer 24 are provided between the unit element 33 a and the photoelectric conversion layer 25. In this case, as shown in Fig. 4B , the length of the resin layer 33, the length of the easy-adhesion layer 32, the length of the base material 31, the length of the bonding layer 37, the length of the second barrier layer 28, the length of the second electrode layer 22, and the length of the second carrier transport layer 24 in the first direction D1 are represented by d2, d3, d4, d5, d6, d7, and d8, respectively. The refractive indexes of the resin layer 33, the easy-adhesion layer 32, the substrate 31, the bonding layer 37, the second barrier layer 28, the second electrode layer 22, and the second carrier transport layer 24 are represented by N2, N3, N4, N5, N6, N7, and N8, respectively. In this case, the radius of curvature R of the unit element 33a is expressed as follows: The following relationship is satisfied.

[0034] In this embodiment, the distance D from the unit element 33 a to the photoelectric conversion layer 25 in the first direction D1 is In this way, when the radius of curvature R satisfies the formula (1) and the distance D satisfies the formula (2), the efficiency of converting light irradiated onto the organic solar cell 20 into electricity can be further improved.

[0035] Here, the refraction at the interface between the layers satisfies the following condition: Here, N' is the refractive index of the layer after refraction. u' is the angle between the light after refraction and the optical axis. N is the refractive index of the layer before refraction. u is the angle between the light before refraction and the optical axis. h is the height of the light before refraction. R is the radius of curvature of the surface.

[0036] Furthermore, the height h' of the ray after refraction is expressed as follows using h, which is the height of the ray before refraction, u', which is the angle between the refracted light and the optical axis, and d', which is the length of the layer after refraction:

[0037] Therefore, for example, as shown in FIG. 4B , the light L incident on the unit element 33a is refracted at the interface between the unit element 33a and the resin layer 33 according to equation (3) so as to satisfy the following equation (5). Note that u2 is the angle between the light L incident on the resin layer 33 and the optical axis. Also, h1 is the height of the light L incident on the unit element 33a. Also, N1 is the refractive index of the low-reflection layer 34. Furthermore, the angle between the light L and the optical axis in the low-reflection layer 34 is set to 0°. Furthermore, the height h2 of the light L after being refracted at the interface between the unit element 33a and the resin layer 33 satisfies the following formula (6) according to formula (4).

[0038] Furthermore, the light L incident on the resin layer 33 is refracted at the interface between the resin layer 33 and the easy-adhesion layer 32 so as to satisfy the following formula (7). Note that u3 is the angle between the light L incident on the adhesive layer 32 and the optical axis.

[0039] In this way, the height h8 of the light L incident on the second carrier transport layer 24 satisfies the following formula (8) based on formulas (4) and (6). Note that h7 is the height of light incident on the second electrode layer 22. Furthermore, u4 to u8 are respectively the angle between the light L incident on the base material 31 and the optical axis, the angle between the light L incident on the bonding layer 37 and the optical axis, the angle between the light L incident on the second barrier layer 28 and the optical axis, the angle between the light L incident on the second electrode layer 22 and the optical axis, and the angle between the light L incident on the second carrier transport layer 24 and the optical axis. Furthermore, in Figure 4B, h7, u5 to u8, and h5 to h8 are omitted from the illustration in order to clarify the drawing.

[0040] Furthermore, the following equation (9) is obtained from equations (7) and (8).

[0041] Here, when the interface between the second carrier transport layer 24 and the photoelectric conversion layer 25 is the light collection position P of the optical member 30, h8 = 0. Therefore, by substituting h8 = 0 into equation (9), the following equation (10) is obtained.

[0042] Furthermore, by modifying equation (5), the following equation (11) is obtained.

[0043] Then, from equations (10) and (11), the following equation (12) is obtained. This formula (8) corresponds to the formula (1) above with X=7.

[0044] In this manner, the radius of curvature R of the unit element 33 a is determined when the interface between the second carrier transport layer 24 and the photoelectric conversion layer 25 is the light-condensing position P of the optical member 30 .

[0045] 4B , the distance D is the sum of the lengths d2 to d8. That is, the distance D corresponds to the above-described formula (2) with X = 7. In this manner, the distance D from the unit element 33a to the photoelectric conversion layer 25 in the first direction D1 can be determined when the interface between the second carrier transport layer 24 and the photoelectric conversion layer 25 is the light collection position P of the optical member 30.

[0046] In the example shown in Fig. 4B, the light collection position P of the optical member 30 is located on the surface of the photoelectric conversion layer 25 of the organic solar cell 20 that faces the optical member 30. However, this is not limiting, and for example, as shown in Fig. 4C, the light collection position P of the optical member 30 may be located within the photoelectric conversion layer 25 of the organic solar cell 20 in the first direction D1. Even in this case, the efficiency of converting light irradiated onto the organic solar cell 20 into electricity can be further improved.

[0047] Furthermore, as shown in FIG. 4D , the resin layer 33 may include a plurality of unit elements 33 a having different depths. That is, the positions of the apexes of the convex shapes formed by the unit elements 33 a in the first direction D1 may not be constant among the plurality of unit elements 33 a. In other words, the positions of the apexes of the convex shapes formed by the unit elements 33 a in the first direction D1 may vary among the plurality of unit elements 33 a. Similarly, the positions of the bottoms of the recesses adjacent to the convex shapes formed by the unit elements 33 a in the first direction D1 may not be constant among the plurality of unit elements 33 a. In other words, the positions of the bottoms of the recesses adjacent to the convex shapes formed by the unit elements 33 a in the first direction D1 may vary among the plurality of unit elements 33 a. Note that, in the example shown in FIG. 4D , the unit elements 33 a are convex toward the second surface 12 (the resin layer 33 side) of the optical member-equipped organic solar cell 10, but this is not limited thereto. For example, as shown in FIG. 4E , the unit elements 33 a may be convex on the first surface 11 side (low-reflection layer 34 side) of the organic solar cell 10 with an optical member. When the unit elements 33 a are convex on the first surface 11 side (low-reflection layer 34 side), it is easy to calculate the optical path of light passing through the photoelectric conversion layer 25, and it is easy to control the light passing through the photoelectric conversion layer 25. This provides an appropriate light-collecting (lens) effect. Furthermore, compared to when the unit elements 33 a are convex on the second surface 12 side (resin layer 33 side), the generation of unnecessary scattered light can be suppressed.

[0048] In a plan view of such an optical member 30, the unit elements 33a may have a polygonal, circular, or elliptical shape. FIGS. 5 to 10 show examples of unit elements 33a in a plan view of the optical member 30. In the example shown in FIG. 5, the unit elements 33a are triangular in shape in a plan view of the optical member 30. In a plan view of the optical member 30, the unit elements 33a may have an equilateral triangular shape or a non-equilateral triangular shape. In a plan view of the optical member 30, the equilateral triangular unit elements 33a may fill a plane. In an example shown in FIG. 6, the unit elements 33a are quadrangular in shape in a plan view of the optical member 30. In a plan view of the optical member 30, the unit elements 33a may have a rectangular shape or a non-rectangular quadrangular shape. In a plan view of the optical member 30, the rectangular unit elements 33a may fill a plane. In an example shown in FIG. 7, the unit elements 33a are pentagonal in shape in a plan view of the optical member 30. The unit elements 33a may have a regular pentagonal shape or a non-regular pentagonal shape in a plan view of the optical member 30. In the example shown in FIG. 8, the unit elements 33a have a hexagonal shape in a plan view of the optical member 30. The unit elements 33a may have a regular hexagonal shape or a non-regular hexagonal shape in a plan view of the optical member 30. In the plan view of the optical member 30, the unit elements 33a having regular hexagonal shapes may fill a plane. In the example shown in FIG. 9, the unit elements 33a have a circular shape in a plan view of the optical member 30. In the example shown in FIG. 10, the unit elements 33a have an elliptical shape in a plan view of the optical member 30.

[0049] In the illustrated example, unit elements 33a overlap in the areas where polygonal, circular, and elliptical shapes overlap. A convex shape formed by one unit element 33a overlaps a convex shape formed by another unit element 33a. In the areas where polygonal, circular, and elliptical shapes overlap, the convex shape protrudes from the other areas.

[0050] In a plan view of the optical member 30, the average distance Dc between the centers of gravity of adjacent unit elements 33a (see FIG. 4A ) may be 0.5 μm or more, 1 μm or more, or 5 μm or more. The average distance Dc between the centers of gravity of adjacent unit elements 33a may be 30 μm or less, 15 μm or less, or 5 μm or less. By setting the average distance Dc between the centers of gravity of adjacent unit elements 33a to 30 μm or less, the pitch of brightness unevenness on the surface of the photoelectric conversion layer 25 can be reduced, thereby improving power generation efficiency. The average distance Dc between the centers of gravity of adjacent unit elements 33a is preferably 5 μm or more and 15 μm or less.

[0051] The center of gravity C of the unit element 33a (see FIG. 4A ) is identified from an image of each unit element 33a in a planar view of the optical member 30. The average of the distances Dc between the centers of gravity of adjacent unit elements 33a is identified as follows. First, an enlarged image of the resin layer 33 within a square area with a side length of 100 μm is obtained in a planar view of the optical member 30. Next, the distances Dc between the centers of gravity of adjacent unit elements 33a are measured from the image, and the average of the measured distances is identified as the average of the distances Dc between the centers of gravity of adjacent unit elements 33a. The enlarged image of the resin layer 33 is acquired using a white light interferometer (resolution: 10 nm or less, measurement magnification: ×100). The distances Dc between the centers of gravity of adjacent unit elements 33a in the acquired image are measured using image processing software "ImageJ."

[0052] When two unit elements 33a are adjacent to each other, the unit elements 33a are in contact with each other. In this case, the boundary between the unit elements 33a can be calculated by binarizing the acquired image. That is, when the unit elements 33a are in contact with each other, the acquired image is first binarized to divide the area within the image. This identifies the boundary between the unit elements 33a. Then, the center of gravity C of the unit elements 33a is identified based on the divided area.

[0053] In the cross section of the optical member 30, the maximum depth Dmax of the unit elements 33a may be 0.1 μm or more, 0.2 μm or more, 3.6 μm or less, or 1.8 μm or less. The depth of the unit elements 33a refers to the length in the thickness direction (first direction D1) of the resin layer 33 from the top of the convex shape formed by the unit elements 33a to the bottom of the concave shape adjacent to the convex shape. The maximum depth Dmax of the unit elements 33a refers to the maximum value of the measured depths of the unit elements 33a (see FIG. 4A ).

[0054] As described above, in this embodiment, in a planar view of the optical member 30, the average distance Dc between the centers of gravity of adjacent unit elements 33a is 0.5 μm or more and 30 μm or less, and the maximum depth Dmax of the unit elements 33a is 0.1 μm or more and 3.6 μm or less. This allows for a moderate light-collecting (lens) effect to be obtained and for glare to be suppressed in the organic solar cell 20. Furthermore, since a moderate light-collecting effect can be obtained, a light-collecting region is provided in the photoelectric conversion layer 25. Furthermore, since a moderate light-collecting effect can be obtained, the occurrence of regions in the photoelectric conversion layer 25 that are not irradiated with light can be suppressed. Here, a disadvantage resulting from the occurrence of regions in the photoelectric conversion layer 25 that are not irradiated with light can be the generation of new electrical resistance. In contrast, in this embodiment, the occurrence of regions in the photoelectric conversion layer 25 that are not irradiated with light can be suppressed, thereby enabling the performance improvement effect obtained by light concentration to be enjoyed without the occurrence of new electrical resistance.

[0055] In the cross section of the optical member 30, the radius of curvature of the surface of the unit element 33a may be 1 μm or more, 10 μm or more, 30 μm or more, or 50 μm or more. The radius of curvature of the surface of the unit element 33a may be 300 μm or less, 200 μm or less, or 100 μm or less. The radius of curvature of the surface of the unit element 33a is preferably 10 μm or more and 100 μm or less. The maximum depth Dmax and the surface curvature radius of the unit element 33a are determined from an image of the cross section of the optical member 30. The image of the cross section of the optical member 30 is acquired using a white light interferometer (resolution: 10 nm or less, measurement area: 100 μm square range, measurement magnification: ×100). The maximum depth Dmax and the surface curvature radius of the unit element 33a in the acquired image are measured using the image processing software "ImageJ."

[0056] The resin layer 33 may be transparent. Specifically, the visible light transmittance of the resin layer 33 may be 90% or more, or 95% or more. The thickness of the resin layer 33 may be 2 μm or more, or 5 μm or less. The material of the resin layer 33 may be an acrylic, silicone-based, or olefin-based resin.

[0057] The resin layer 33 may have adhesive properties. In this case, the easy-adhesion layer 32 may be omitted from the optical member 30. The resin layer 33 may exhibit an anti-reflection function by having a concave-convex pattern. In this case, the low-reflection layer 34 may be omitted from the optical member 30. The resin layer 33 may be provided with weather resistance. In this case, the surface layer 35 may be omitted from the optical member 30.

[0058] The low-reflection layer 34 suppresses reflection in the optical element 30. The low-reflection layer 34 includes, for example, multiple layers with different refractive indices. Light reflected at the interfaces between the layers with different refractive indices weakens each other, thereby preventing the light reflected in the optical element 30 from being observed. The low-reflection layer 34 is transparent. Specifically, the visible light transmittance of the low-reflection layer 34 may be 90% or more, or 95% or more. The thickness of the low-reflection layer 34 may be 0.8 nm or more, or 1 μm or less. The low-reflection layer 34 may be formed by disposing a UV-curable resin such as urethane acrylate on an acrylic or triacetyl cellulose (TAC) substrate, irradiating the resin with UV light to cure the resin, and then disposing an acrylic UV-curable resin and irradiating the resin with UV light to cure the resin. The low-reflection layer 34 may be omitted from the optical element 30.

[0059] The surface layer 35 protects the other layers of the optical member 30 from the outside. The surface layer 35 may have, for example, an antifouling function or a water-repellent function. The surface layer 35 may have abrasion resistance, weather resistance, chemical resistance, etc. The surface layer 35 is a thin film. The surface layer 35 is transparent. Specifically, the visible light transmittance of the surface layer 35 may be 90% or more, or 95% or more. The thickness of the surface layer 35 may be 1 μm or more, 2 μm or more, or 40 μm or less, or 30 μm or less. The material of the surface layer 35 may be a cured product of a curable resin composition. More specifically, the material of the surface layer 35 may be a cured product of an ionizing radiation-curable resin composition. In the optical member 30, the surface layer 35 may be omitted.

[0060] The bonding layer 37 bonds the optical element 30 directly to the organic solar cells 20 or bonds the optical element 30 to the organic solar cells 20 via the refractive index adjustment layer 15. The bonding layer 37 is located closest to the organic solar cells 20 on the optical element 30. The bonding layer 37 may be transparent. Specifically, the visible light transmittance of the bonding layer 37 may be 90% or more, or 95% or more. The bonding layer 37 is thin-film-like. The thickness of the bonding layer 37 may be, for example, 1 μm or more or 10 μm or less. The bonding layer 37 may be any one of an adhesive, an optically clear adhesive (OCA), a heat seal, a UV-curable resin, or a combination thereof. The adhesive may be, for example, ethylene vinyl acetylate or polyvinyl butyral. The heat seal may be, for example, a vinyl chloride-vinyl acetate copolymer, an acrylic resin, a polyester resin, or a urethane resin. The UV-curable resin may be, for example, an acrylic resin. In cases where the optical member 30 can be bonded to the organic solar cell 20 by the refractive index matching layer 15, the bonding layer 37 may be omitted from the optical member 30.

[0061] The haze value of the optical member 30 may be 1% or more, 3% or more, or 5% or more. The haze value of the optical member 30 may be 60% or less, 30% or less, or 20% or less. The haze value of the optical member 30 is preferably 1% or more and 20% or less. The haze value of the optical member 30 is due to the uneven pattern formed on the surface of the resin layer 33. The haze value is expressed as the ratio of the diffuse transmittance to the total luminous transmittance of the target object, and refers to the diffusion rate of light passing through the target object. The total luminous transmittance is the ratio of the amount of light passing through the target object to the amount of light entering the target object. The diffuse transmittance is the ratio of the amount of light passing through the target object in directions other than the linear direction to the amount of light entering the target object, i.e., the amount of light that is diffused and transmitted. The total luminous transmittance and diffuse transmittance are measured using a haze meter (NDH7000 manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7361-1.

[0062] In organic solar cells, electrons and holes tend to disappear by combining with other electrons and holes within the photoelectric conversion layer. It is difficult for electrons and holes to travel long distances within the photoelectric conversion layer. To move electrons and holes from the photoelectric conversion layer to the electrode layer, it is necessary to make the photoelectric conversion layer thin. Making the photoelectric conversion layer thin makes it difficult for the photoelectric conversion layer to absorb light. This results in a decrease in the efficiency of converting light into electricity.

[0063] One way to improve the efficiency of the photoelectric conversion layer in converting light into electricity is to overlay a prism on an organic solar cell. By appropriately refracting light through a prism, the light passes through the photoelectric conversion layer in a direction tilted relative to its normal direction. This lengthens the optical path that the light takes through the photoelectric conversion layer. This is thought to improve the efficiency of converting light into electricity. However, the prism itself also absorbs light. The rate at which the prism improves the efficiency of the photoelectric conversion layer in converting light into electricity is likely to be lower than the rate at which light is absorbed by the prism. Simply providing a prism is difficult to sufficiently improve the efficiency of the photoelectric conversion layer in converting light into electricity.

[0064] In the optical member 30 overlaid on the organic solar cell 20 of the present embodiment, the resin layer 33 includes a plurality of unit elements 33a arranged two-dimensionally to form a concave-convex pattern. In a plan view of the optical member 30, the average distance Dc between the centers of gravity of two adjacent unit elements 33a is 0.5 μm or more and 30 μm or less. In a cross section of the optical member 30, the maximum depth Dmax of the unit elements 33a is 0.1 μm or more and 3.6 μm or less. It is believed that such an optical member 30 can improve the efficiency of converting light incident on the organic solar cell 20 into electric power for the reason speculated below. However, the reason why the optical member 30 of the present embodiment improves the efficiency of converting light incident on the organic solar cell 20 into electric power is not limited to the speculation below.

[0065] Light passing through the unit elements 33a, which are two-dimensionally arranged to form a concave-convex pattern, is focused due to the concave-convex shape. In other words, the unit elements 33a function as lenses, focusing light passing through the resin layer 33. Furthermore, when the average distance Dc between the centers of gravity of two adjacent unit elements 33a and the maximum depth Dmax of the unit elements 33a are within appropriate ranges, light passing through the resin layer 33 is diffracted. Light passing through the resin layer 33 interferes with one another, resulting in varying light intensities. When the focused light and the strong light generated by the interference are absorbed by the photoelectric conversion layer 25, a high voltage difference is likely to occur in the photoelectric conversion layer 25 due to the excited electrons and holes. Electrons and holes excited by weak light absorbed by the photoelectric conversion layer 25 can migrate to the electrode due to this high voltage difference. Electrons and holes generated by weak light also easily migrate to the electrode. The strong light allows electrons and holes generated by light incident on the photoelectric conversion layer 25 to migrate efficiently. The efficiency of converting light incident on the organic solar cell 20 into electric power can be improved.

[0066] The multiple unit elements 33a are arranged two-dimensionally. Light passing through the resin layer 33 can be dispersed in multiple directions. The dispersed light is incident on the organic solar cell 20 on which the optical member 30 is superimposed. The dispersed light passes through the photoelectric conversion layer in a direction inclined relative to the normal direction of the photoelectric conversion layer. The optical path that the light passes through the photoelectric conversion layer is lengthened. The efficiency of converting light into electricity can be improved.

[0067] The optical member 30 is overlaid on the organic solar cell 20. The optical member 30 can be easily overlaid on an existing organic solar cell 20. By overlaying the optical member 30, the efficiency of converting light incident on the existing organic solar cell 20 into electricity can be easily improved.

[0068] The haze value of the optical member 30 is 1% or more and 60% or less. Because the haze value is sufficiently high, light passing through the optical member 30 can be dispersed. The dispersed light is incident on the organic solar cell 20 on which the optical member 30 is overlaid. The dispersed light passes through the photoelectric conversion layer in a direction inclined relative to the normal direction of the photoelectric conversion layer. The optical path along which light passes through the photoelectric conversion layer is lengthened. The efficiency of converting light into electricity can be improved. If the haze value is not too high, the transparency of the optical member 30 is less likely to be impaired. The organic solar cell 10 with the optical member can be made transparent. For example, the organic solar cell 10 with the optical member can be attached to a transparent member such as a window and used.

[0069] In the cross section of the optical member 30, the radius of curvature of the surface of the unit elements 33a is 1 μm or more and 300 μm or less. A sufficiently large radius of curvature makes it difficult for unintended light scattering to occur in the unit elements 33a. Light incident on the optical member 30 can be appropriately transmitted and directed toward the organic solar cells 20. This prevents a decrease in the light directed from the optical member 30 to the organic solar cells 20, thereby preventing a decrease in the efficiency of converting light into electricity. By not making the radius of curvature of the surface of the unit elements 33a too large, the average distance Dc between the centers of gravity of two adjacent unit elements 33a and the maximum depth Dmax of the unit elements 33a can be adjusted within appropriate ranges. The optical member 30 can improve the efficiency of converting light incident on the organic solar cells 20 into electricity.

[0070] In a plan view of the optical member 30, the unit elements 33a are polygonal, circular, or elliptical. Light incident on the unit elements 33a is bent in multiple directions. For example, if the unit elements 33a are pentagonal, light incident on the unit elements 33a is bent in five directions. For example, if the unit elements 33a are circular or elliptical, light incident on the unit elements 33a is bent in all directions. Light transmitted through the optical member 30 can be dispersed in multiple directions. The dispersed light is incident on the organic solar cell 20 on which the optical member 30 is overlaid. The dispersed light passes through the photoelectric conversion layer in a direction inclined relative to the normal direction of the layer. The optical path along which light passes through the photoelectric conversion layer is lengthened. The efficiency of converting light into electricity can be improved.

[0071] In the organic solar cell 10 with an optical member of this embodiment, the light collection position of the optical member 30 is located on the surface of the photoelectric conversion layer 25 that faces the optical member 30. Such an organic solar cell 10 with an optical member can further improve the efficiency of converting light irradiated onto the organic solar cell 20 into electricity.

[0072] In the organic solar cell 10 with an optical member of the present embodiment, when the length in the first direction D1 of the Mth layer (M is a natural number of 1 or more and X or less) from the unit element 33a is d(M+1), the refractive index of the unit element 33a is N1, and the refractive index of the Mth layer from the unit element 33a in the first direction D1 is N(M+1), the radius of curvature R of the unit element 33a is The distance D from the unit element 33a to the photoelectric conversion layer 25 in the first direction D1 satisfies the following relationship: This satisfies the following relationship: It is possible to further improve the efficiency of converting light irradiated onto the organic solar cell 20 into electricity.

[0073] The aspects of the present disclosure are not limited to the above-described embodiments, but include various modifications that may be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the contents of the above-described embodiments. Various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and intent of each disclosure derived from the contents defined in the claims and their equivalents.

[0074] The present disclosure will be described in more detail with reference to examples, but the present disclosure is not limited to the following examples.

[0075] As an example, an organic solar cell with an optical element was prepared, in which an optical element was overlaid on an organic solar cell. The optical element only had a substrate and a resin layer provided on the substrate. The thickness of the substrate was 50 μm. The material of the substrate was polyethylene terephthalate. The resin layer included a plurality of unit elements. The plurality of unit elements were two-dimensionally arranged to form a concave-convex pattern. The unit elements had different designs among the multiple examples. As a comparative example, an organic solar cell without an optical element overlaid was prepared. The organic solar cells were the same in the example and the comparative example. More specifically, different optical elements were overlaid on the same organic solar cell to create organic solar cells with optical elements of different examples.

[0076] In the optical member according to Example 1, the average distance between the centers of gravity of adjacent unit elements was 10 μm, the maximum depth of the unit elements was 0.6 μm, and the radius of curvature of the surface of the unit elements was 45 μm.

[0077] In the optical member according to Example 2, the average distance between the centers of gravity of adjacent unit elements was 10 μm, the maximum depth of the unit elements was 0.5 μm, and the radius of curvature of the surface of the unit elements was 45 μm.

[0078] In the optical member according to Example 3, the average distance between the centers of gravity of adjacent unit elements was 10 μm, the maximum depth of the unit elements was 0.4 μm, and the radius of curvature of the surface of the unit elements was 60 μm.

[0079] The total light transmittance and haze value of the optical members according to each example were measured using a haze meter (NDH7000 manufactured by Nippon Denshoku Industries Co., Ltd.) conforming to JIS K7361-1. The total light transmittance of the optical member according to example 1 was 91.4%, and the haze value was 13.9%. The total light transmittance of the optical member according to example 2 was 91.6%, and the haze value was 9.7%. The total light transmittance of the optical member according to example 3 was 91.8%, and the haze value was 6.0%.

[0080] The short-circuit current was measured as an indicator of the efficiency of light-to-electricity conversion for the organic solar cells with optical components of each example and the organic solar cells of the comparative example. White light from a D65 light source was irradiated onto the organic solar cells with optical components of each example and the organic solar cells of the comparative example. The efficiency of light-to-electricity conversion of an organic solar cell can change depending on the number of short-circuit current measurements, due to changes in its crystalline structure, etc. The short-circuit current of the organic solar cells with optical components of each example and the organic solar cells of the comparative example was measured alternately to reduce the influence of efficiency changes depending on the number of measurements in the short-circuit current measurements for each example. The measurement results are shown in Figure 11. In Figure 11, the measured short-circuit current was normalized by dividing by 15 mA. As shown in Figure 11, the short-circuit current of the organic solar cell of the comparative example was measured at the first, third, fifth, seventh, ninth, and eleventh measurements. The short-circuit current of the organic solar cell with optical components of Example 3 was measured at the second measurement. The short-circuit current of the organic solar cell with optical components of Example 2 was measured at the fourth measurement. The short-circuit current of the organic solar cell with optical components of Example 1 was measured at the eighth measurement. In the sixth and tenth times, the organic solar cell was irradiated with light, but no measurements were made.

[0081] As can be seen from the graph shown in Figure 11, by overlaying the optical member on the organic solar cell, the short-circuit current generated in the organic solar cell when irradiated with light is improved. It was confirmed that by overlaying the optical member of the example, the efficiency of converting light irradiated on the organic solar cell into electricity can be improved.

Claims

1. An optical component to be overlaid on an organic solar cell, comprising: a substrate; and a resin layer provided on the substrate; wherein the resin layer includes a plurality of unit elements that are two-dimensionally arranged in a plan view of the optical component so as to form a concave-convex pattern; wherein the average distance between the centers of gravity of two adjacent unit elements in a plan view of the optical component is 0.5 μm or more and 30 μm or less; and wherein the maximum depth of the unit elements in a cross section of the optical component is 0.1 μm or more and 3.6 μm or less.

2. The optical element according to claim 1, wherein the haze value of the optical element is 1% or more and 60% or less.

3. The optical member according to claim 1, wherein the radius of curvature of the surface of said unit element in the cross section of said optical member is 1 μm or more and 300 μm or less.

4. The optical member according to claim 1, wherein, in a plan view of the optical member, the unit elements have a polygonal, circular or elliptical shape.

5. An organic solar cell with an optical element, comprising: the optical element according to claim 1; and an organic solar cell having the optical element overlaid thereon.

6. An organic solar cell with an optical member, comprising: an optical member; and an organic solar cell having the optical member superimposed thereon, wherein the optical member has a base material and a resin layer provided on the base material, the resin layer including a plurality of unit elements arranged to form a concave-convex pattern, the organic solar cell having at least a photoelectric conversion layer, and the light collecting position of the optical member is located on the surface of the photoelectric conversion layer facing the optical member.

7. An organic solar cell with an optical element, comprising: an optical element; and an organic solar cell having the optical element overlaid thereon, wherein the optical element has, in a first direction, a base material and a resin layer provided on the base material, in this order; the resin layer includes a plurality of unit elements arranged to form a concave-convex pattern; the organic solar cell has at least a photoelectric conversion layer; and the light collection position of the optical element is located within the photoelectric conversion layer in the first direction.

8. An organic solar cell comprising an optical element and an organic solar cell having the optical element stacked thereon, wherein the optical element has, in a first direction, a substrate and a resin layer provided on the substrate in this order, and the resin layer includes a plurality of unit elements arranged to form a concave-convex pattern, and the organic solar cell has at least a photoelectric conversion layer, and X layers (X is a natural number of 1 or more) are provided between the unit elements and the photoelectric conversion layer, wherein the radius of curvature of the unit elements is R, the length in the first direction of an Mth layer (M is a natural number of 1 or more and X or less) from the unit element in the first direction is d(M+1), the refractive index of the unit elements is N1, and the refractive index of the Mth layer from the unit element in the first direction is N(M+1), The distance D from the unit element to the photoelectric conversion layer in the first direction satisfies the following relationship: An organic solar cell with optical components that satisfies the above relationship.

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