JP6670991B2 - Solar cell - Google Patents

Description

  The present disclosure relates to a solar cell used for photovoltaic power generation.

  Patent Document 1 discloses a concentrating solar cell provided with an optical member having an integral structure for integrating a converging lens and a solar cell. As a result, the sunlight is concentrated on the elements constituting the solar cell without waste, and the output is improved.

International Publication No. 2012/160994

  The present disclosure provides a solar cell with improved light use efficiency.

  A solar cell according to the present disclosure has a light-receiving lens having a light-condensing action, a light-guiding member disposed on the light-emitting surface side of the light-receiving lens, and a light-transmitting member disposed in contact with the light-emitting member. The substrate includes a substrate and a photoelectric conversion element that is provided at a position facing the light guide member and receives light emitted from the substrate. And the incident surface of a light guide member is comprised by a convex surface.

  The solar cell according to the present disclosure can improve light use efficiency.

Schematic sectional view showing the configuration of the solar cell according to the present embodiment Sectional drawing explaining the optical path of the sunlight which injects into the solar cell concerning the embodiment. Sectional drawing which shows the optical path of the short wavelength light and the long wavelength light which inject into the light guide member concerning the embodiment. Sectional drawing which shows the optical path of a short wavelength light ray and a long wavelength light ray which enter a light guide member consisting only of a light guide part 4 is a graph showing a relationship between a photoelectric conversion wavelength band and a focal length of the photoelectric conversion element according to the embodiment.

  Hereinafter, embodiments will be described in detail with reference to the drawings. However, an unnecessary detailed description may be omitted. For example, a detailed description of a well-known item or a redundant description of substantially the same configuration may be omitted. This is to prevent the following description from being unnecessarily redundant and to facilitate understanding by those skilled in the art.

  The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the claimed subject matter.

(Embodiment)
[1. Constitution]
[1-1. overall structure]
Hereinafter, the entire configuration of solar cell 100 in the present embodiment will be described with reference to FIG.

  FIG. 1 is a schematic sectional view showing the configuration of the solar cell according to the present embodiment.

  As shown in FIG. 1, solar cell 100 of the present embodiment mainly includes light receiving lens array 110, light guide member 120, glass substrate 130 having translucency, photoelectric conversion element 140, and the like. .

  The light receiving lens array 110 is configured by arranging a plurality of light receiving lenses 110a in an array. The light receiving lens 110a has, for example, a convex incident surface 110b and an exit surface 110c. Light such as sunlight that has entered the light receiving lens array 110 is collected by the lens surfaces of the respective light receiving lenses 110a.

  In addition, the solar cell 100 of the present disclosure may include a sunlight tracking device (not shown) on the incident surface 110b side of the light receiving lens array 110. Thereby, the solar cell 100 can always make sunlight enter the light receiving lens 110a substantially parallel (including parallel) to the optical axis L of the light receiving lens 110a regardless of the position of the sun. As a result, high conversion efficiency can be maintained.

  The light receiving lens 110a of the present embodiment is configured by a lens having a positive power, formed of, for example, an acrylic resin. The material of the light receiving lens 110a is not limited to acrylic resin, but may be another resin material, glass, or the like.

  The light guide member 120 includes a convex lens 121 whose entrance surface 121 a is formed as a convex surface, and a light guide unit 122. The light guide member 120 is arranged at a predetermined position on the light exit surface 110c side of the light receiving lens 110a. At this time, a plurality of light guide members 120 are also arranged in an array corresponding to the light receiving lenses 110a arranged in an array. In addition, the convex lens 121 is exemplified as a convex portion of the light guide member 120.

  Then, the outgoing light emitted from the outgoing surface 110c of the light receiving lens 110a enters the convex lens 121 forming the convex portion of the light guide member 120. The incident light is condensed by a convex lens 121 having a convex shape and is incident on the light guide 122. Although the light guide member 120 of the present disclosure is described as an example in which the convex lens 121 and the light guide unit 122 are formed separately, they may be formed integrally.

  On the glass substrate 130, the light guide member 120 and the photoelectric conversion element 140 are provided at positions facing each other with the glass substrate 130 interposed therebetween. Note that the glass substrate 130 is shown as an example of the substrate. Therefore, the substrate is not limited to glass and may have high light-transmitting properties with respect to sunlight. For example, you may comprise with resin, such as acrylic.

  The photoelectric conversion element 140 is made of one or more light absorbing materials that absorb sunlight. Specifically, the photoelectric conversion element 140 has a multi-junction structure in which a plurality of types of pn junctions having different absorption wavelength bands are stacked. In this embodiment, for example, a multi-junction solar cell having three layers such as InGaP, GaAs, and GaInAsN is used to convert light in a wavelength range of 400 nm to 1300 nm into electric energy. That is, the photoelectric conversion element 140 of this embodiment has a photoelectric conversion wavelength band from a wavelength of 400 nm to a wavelength of 1300 nm. The photoelectric conversion element 140 is arranged at a position facing the light guide member 120 with the glass substrate 130 interposed therebetween.

  The solar cell 100 further includes a water-repellent film 150, an anisotropic conductive film (Anisotropic Conductive Film) 160, a wiring substrate 170, a heat sink 180, and the like on the emission surface 130b side of the glass substrate 130.

  Next, the operation of solar cell 100 in the present embodiment will be described.

  The sunlight is collected on the photoelectric conversion element 140 via the light receiving lens 110a and the like. The light receiving lens 110a, the light guide member 120, and the photoelectric conversion element 140 are each configured as a pair, and a plurality of pairs are arranged in an array.

  The shape of the light receiving surface of the light receiving lens 110a viewed from the direction of the optical axis L may be various shapes such as a rectangle, a circle, and a polygon such as a regular hexagon. However, in the case of a concentrating solar cell in which the amount of power generation per unit area is important, a shape such as a rectangle or polygon that can be arranged in an array without any gap is preferable.

  The incident surface 110b of the light receiving lens 110a is formed, for example, in an aspherical shape. The aspherical shape is determined so as to reduce the increase in the size of the focused spot due to aberration. Thus, it is possible to suppress a decrease in the power generation efficiency of the solar cell 100 due to aberration of the light receiving lens 110a.

  As described above, the photoelectric conversion element 140 converts light energy of sunlight in a photoelectric conversion wavelength band into electric energy. The electric energy converted by the photoelectric conversion element 140 is extracted from the wiring substrate 170 through the anisotropic conductive film 160. The anisotropic conductive film 160 maintains insulation in the plane direction and has conductivity in the thickness direction. Thus, the electrodes of the photoelectric conversion element 140 and the wiring of the wiring board 170 are electrically connected. In addition, since the solar cell 100 collects and converts sunlight, the temperature tends to increase. Therefore, a heat sink 180 is provided to keep the solar cell 100 at an appropriate operating temperature.

  As described above, solar cell 100 of the present embodiment is configured.

  Hereinafter, a method for bonding the photoelectric conversion element 140 to the glass substrate 130 will be described.

  First, a water-repellent film 150 such as, for example, (2-perfluorooctyl) ethyltrimethoxysilane is applied to the emission surface 130b of the glass substrate 130. Thereafter, a predetermined position on the surface on which the water-repellent film 150 has been applied is irradiated with, for example, light having a wavelength of 450 nm. The water-repellent film 150 is formed of a material that becomes hydrophilic when irradiated with light. As a result, in the water-repellent film 150 applied to the emission surface 130b of the glass substrate 130, only the spot-shaped region irradiated with light changes to hydrophilic. Note that the predetermined position is a position facing the emission surface 122b of the light guide unit 122 of the light guide member 120 disposed on the incident surface 130a side of the glass substrate 130. Although not described, the light guide member 120 is bonded to the glass substrate 130 by the same bonding method as that of the photoelectric conversion element 140.

  Next, in the above state, a transparent adhesive such as silicone is applied on the water-repellent film 150 on the emission surface 130b of the glass substrate 130. At this time, the applied transparent adhesive gathers in the region of the water-repellent film 150 that has changed to hydrophilic.

  Next, the photoelectric conversion element 140 is disposed on the transparent adhesive and fixed by adhesion. Thereby, the photoelectric conversion element 140 is disposed at a predetermined position facing the light guide member 120 with the glass substrate 130 interposed therebetween.

[1-2. Light receiving lens]
Hereinafter, the light receiving lens 110a will be described with reference to FIG.

  FIG. 2 is a cross-sectional view illustrating an optical path of sunlight incident on the solar cell according to the present embodiment.

  Generally, when the solar cell 100 receives substantially parallel light 200 (including parallel light 200) such as sunlight from the vertical direction, the power of the incident surface 110b is set to be larger than the power of the output surface 110c of the light receiving lens 110a. The better the aberration characteristics are.

  However, when the power of the light receiving lens 110a is increased, the thickness of the light receiving lens 110a increases. In this case, a configuration in which the convex surface forming the incident surface 110b of the light receiving lens 110a has a Fresnel shape in order to suppress an increase in thickness is known as a known technique. However, when the incident surface 110b side of the light receiving lens 110a has a Fresnel shape, vignetting of light rays occurs due to the cutout surface of the Fresnel lens. As a result, the light beam that reaches the photoelectric conversion element 140 is lost, and the converted light energy is reduced.

  Therefore, in the light receiving lens 110a of the present embodiment, as shown in FIG. 2, the incident surface 110b is formed as an aspherical convex surface having a positive power, and the output surface 110c is formed as a Fresnel shape having a positive power. At this time, the emission surface 110c has a Fresnel shape of a flat substrate with a constant height of the cutout surface. Thus, the thickness (wall thickness) of the light receiving lens 110a is reduced.

  In the light receiving lens 110a of the present embodiment, the positive power of the light exit surface 110c is set to be larger than the positive power of the light incident surface 110b. Thus, the thickness of the light receiving lens 110a can be reduced.

  Specifically, as shown in FIG. 3, the power (1 / focal length) of the light receiving lens 110a is set such that the position of the focal point for each wavelength caused by the axial chromatic aberration is as follows. .

  FIG. 3 is a sectional view showing an optical path of a short wavelength light and a long wavelength light incident on the light guide member according to the embodiment. FIG. 3 illustrates a case where the short wavelength light 200a has a wavelength of 400 nm, the middle wavelength light 200c has a wavelength of 510 nm, and the long wavelength light 200b has a wavelength of 1300 nm, which corresponds to the photoelectric conversion wavelength band of the photoelectric conversion element 140. I have.

  That is, in the case of the short-wavelength light beam 200a shown in FIG. 3, the focal position FP400 (Focal Point) of the light having a wavelength of 400 nm in the light emitted from the light receiving lens 110a is closer to the light receiving lens 110a than the vertex 121c of the convex lens 121 of the light guide member 120. Is set to the position. On the other hand, as shown in the long-wavelength light beam 200b in FIG. 3, the focal position FP1300R of the light having the wavelength of 1300 nm is set in a position where the light guide 122 of the light guide member 120 is arranged. That is, on the optical axis L, between the focal position FP400 of the short wavelength light beam 200a and the focal position FP1300R of the long wavelength light beam 200b, the convex lens 121 constituting the convex portion of the light guide member 120 is set. doing.

  Further, as described later, in the case of the medium wavelength light beam 200c shown in FIG. 3, the focal position FP510 of the light having a wavelength of 510 nm in the light emitted from the light receiving lens 110a is set to the incident surface 122a of the light guide unit 122 of the light guide member 120, or It is set to a nearby position.

  Here, the relationship between the wavelength incident on the light receiving lens 110a and the focal length will be described with reference to FIG.

  FIG. 5 is a graph showing the amount of change in the focal length of the light receiving lens 110a when light having a wavelength of 400 nm to 1300 nm, which is the photoelectric conversion wavelength band of the photoelectric conversion element 140, enters. The horizontal axis indicates the wavelength of light incident on the light receiving lens 110a, and the vertical axis indicates the distance of the incident light to the focal position of the light receiving lens 110a. Since the focal length varies depending on design factors such as the shape and power of the light receiving lens 110a, it is not determined uniquely and is shown relatively.

  At this time, as shown in FIG. 5, the position is located at an intermediate point of the distance from the focal length of the light receiving lens 110a when the light having the wavelength of 400 nm is incident to the focal length of the light receiving lens 110a when the light having the wavelength of 1300 nm is incident. The wavelength of the emitted light (wavelength at the central value of the amount of change in the focal length) corresponds to 510 nm.

  Therefore, in the present embodiment, as shown in FIG. 3, the focal position FP510 of the light receiving lens 110a when the light having the wavelength of 510 nm, which is the medium-wavelength light beam 200c, is incident on the incident surface 122a of the light guide 122 or in the vicinity thereof. The light guide section 122 is arranged so as to be located at the position. That is, the distance from the focal position FP400 of the light having the wavelength of 400 nm to the position of the incident surface 122a of the light guide 122 and the distance from the position of the incident surface 122a of the light guide 122 to the focal position FP1300R of the light having the wavelength of 1300 nm are: The light guides 122 are arranged so as to be substantially equal. Then, a light receiving lens 110a having the above focal length is designed for each wavelength. This suppresses an increase in the size of the condensed spot on the photoelectric conversion element on the short wavelength and long wavelength side due to axial chromatic aberration of the light receiving lens 110a. As a result, it is possible to suppress the light amount loss in the entire light receiving wavelength range of sunlight reaching the photoelectric conversion element 140 from the light receiving lens 110a. Further, light in the photoelectric conversion wavelength band of the photoelectric conversion element 140 can be made incident on the photoelectric conversion element 140 without loss. As a result, a solar cell 100 with high light use efficiency is obtained.

  According to the light receiving lens 110a of the present embodiment, aberrations in the short wavelength end, the long wavelength end, and the wavelength region near the short wavelength end and the long wavelength end of the photoelectric conversion element 140 can be favorably suppressed. Further, by suppressing the power of the incident surface 110b, an increase in the thickness of the light receiving lens 110a can be suppressed. As a result, the size and weight of the solar cell 100 can be reduced.

  Further, by making the incident surface 110b of the light receiving lens 110a a convex surface, vignetting of incident sunlight can be prevented and light can be effectively collected. Further, by forming the exit surface 110c of the light receiving lens 110a in a Fresnel shape, the focal length for incident light can be further reduced. As a result, the size of the solar cell 100 can be reduced.

[1-3. Light guide member]
Hereinafter, the light guide member 120 will be described with reference to FIG.

  As shown in FIG. 3, light guide member 120 of the present embodiment is arranged to face photoelectric conversion element 140 with glass substrate 130 constituting the substrate interposed therebetween. The light guide member 120 is arranged on the emission surface 130b side of the glass substrate 130, and the photoelectric conversion element 140 is adhered and arranged on the incident surface 130a side of the glass substrate 130.

  The light guide member 120 has a convex lens 121 forming a convex portion and a light guide portion 122. The exit surface 121b of the convex lens 121 and the entrance surface 122a of the light guide 122 are formed in close contact. In the convex lens 121, the entrance surface 121a has a convex shape having a positive power, and the exit surface 121b has a planar shape. Then, the convex lens 121 guides outgoing light incident on the incident surface 121 a and emitted from the outgoing surface 121 b to the light guide unit 122.

  The light guide unit 122 includes, for example, a rod integrator. The shape of a cross section (hereinafter, referred to as a vertical cross section) parallel to the optical axis L of the light guide portion 122 is formed in a tapered shape from the incident surface 122a side to the emission surface 122b side. Thereby, the light incident on the light guide unit 122 can be effectively applied to the photoelectric conversion element 140.

  At this time, the area (corresponding to the maximum cross-sectional area) of the exit surface 121b of the convex lens 121 is the same as the area (corresponding to the maximum cross-sectional area) of the incident surface 122a of the light guide 122. Thereby, the light incident on the convex lens 121 can be surely incident on the incident surface 122a of the light guide 122.

  The shape of a cross section perpendicular to (perpendicular to) the optical axis L of the convex lens 121 and the light guide 122 (hereinafter, referred to as a cross section) is formed, for example, in a square shape in accordance with the shape of the light receiving lens 110a. Further, the light guide 122 is formed such that the area of the incident surface 122a is larger than the area of the emission surface 122b. That is, the vertical cross-sectional shape from the incident surface 122a to the emission surface 122b of the light guide 122 is tapered. In addition, as shown in FIG. 3, the light guide 122 is not limited to a shape in which the area of the cross section gradually decreases. Other shapes may be used as long as the condition that the incident surface 122a of the light guide 122 is larger than the exit surface 122b is satisfied. For example, the vertical cross-sectional shape of the light guide 122 may be such that a line extending from the entrance surface 122a to the exit surface 122b is formed as a curve like a parabola.

  Hereinafter, in solar cell 100 of the present embodiment, an optical path of sunlight collected by light receiving lens 110a will be described with reference to FIGS.

  FIG. 4 is a cross-sectional view showing an optical path of a short-wavelength light beam and a long-wavelength light beam incident on a light guide member including only a light guide section. FIG. 4 is a diagram for comparison with an optical path of a light guide member having a convex portion according to the present embodiment. That is, FIG. 4 illustrates the optical path of sunlight when the light guide member 120 including only the light guide unit 122 is used and arranged in the same dimensional relationship as in FIG. 3.

  First, as described above, the short-wavelength light beam 200a illustrated in FIGS. 3 and 4 indicates the optical path of sunlight having a wavelength of 400 nm after being collected by the light receiving lens 110a. The long-wavelength light beam 200b indicates an optical path of sunlight having a wavelength of 1300 nm after being collected by the light receiving lens 110a.

  That is, as shown in FIG. 3, the short-wavelength light beam 200a condensed by the light receiving lens 110a is closer to the light receiving lens 110a than the vertex 121c of the incident surface 121a of the convex lens 121 due to the axial chromatic aberration of the light receiving lens 110a. The light is focused on the focal point FP400 on the optical axis L. The short-wavelength light beam 200a condensed at the focal position FP400 is incident on the incident surface 121a of the convex lens 121 having a condensing function while diverging, and is transmitted. At this time, the short-wavelength light beam 200 a enters the light guide unit 122 while the divergence angle is suppressed by the convex lens 121 of the light guide member 120. The short-wavelength light beam 200a incident on the light guide 122 enters from the incident surface 130a of the glass substrate 130 while being totally reflected by the tapered side surface 122c of the light guide 122. The short-wavelength light beam 200a that has entered the glass substrate 130 enters the photoelectric conversion element 140 from the emission surface 130b of the glass substrate 130. At this time, the light receiving lens 110 a, the light guide member 120, and the glass substrate 130 are arranged at predetermined positions so that the short-wavelength light beam 200 a reliably enters the entire surface of the photoelectric conversion element 140. Thereby, the photoelectric conversion element 140 can efficiently convert the short-wavelength light beam 200a into electric energy.

  The long-wavelength light beam 200 b illustrated in FIG. 3 is incident on the light guide unit 122 after the focal position is adjusted by the convex lens 121 of the light guide member 120. The long-wavelength light beam 200b that has entered the light guide unit 122 is condensed at a focal position FP1300R on the optical axis L. The long-wavelength light beam 200b after being condensed at the focal position FP1300R enters from the incident surface 130a of the glass substrate 130 while diverging. The long-wavelength light 200b incident on the glass substrate 130 is incident on the entire surface of the photoelectric conversion element 140 from the emission surface 130b of the glass substrate 130. That is, the long-wavelength light beam 200b is adjusted by the convex lens 121 to the focal position FP1300R, and is emitted such that the divergence angle coincides with the entire surface of the photoelectric conversion element 140. Thereby, the photoelectric conversion element 140 can efficiently convert the long-wavelength light beam 200b into electric energy.

  On the other hand, as shown in FIG. 4, when the light guide member 120 does not have the convex lens 121, the short-wavelength light beam 200a emitted from the light receiving lens 110a is focused on the focal position FP400 on the optical axis L. Note that the focal position FP400 in FIG. 4 is arranged in the same dimensional relationship, and thus has the same position as the focal position FP400 in FIG.

  Then, the light condensed at the focal position FP400 is directly incident from the incident surface 122a of the light guide unit 122 while diverging. The short-wavelength light beam 200a incident on the light guide unit 122 passes through the glass substrate 130 and is incident on the photoelectric conversion element 140 while being totally reflected on the side surface 122c of the light guide unit 122. In this case, as shown in FIG. 4, a part of the short-wavelength light beam 200a cannot enter the photoelectric conversion element 140. Therefore, when the light guide member 120 does not include the convex lens 121, the light use efficiency of the solar cell 100 decreases.

  In addition, the long-wavelength light beam 200b illustrated in FIG. 4 is directly incident from the incident surface 122a of the light guide unit 122. The long-wavelength light beam 200b incident on the light guide 122 is focused on the focal position FP1300 of the light receiving lens 110a on the optical axis L. At this time, the focal position FP1300 is closer to the photoelectric conversion element 140 than the focal position FP1300R shown in FIG. Therefore, the long-wavelength light beam 200b collected at the focal position FP1300 diverges, passes through the glass substrate 130, and is incident on a part of the surface of the photoelectric conversion element 140. At this time, the resistance of a part of the photoelectric conversion element 140 not irradiated with light increases. Therefore, the conversion efficiency of the photoelectric conversion element 140 decreases.

  In the case of the configuration shown in FIG. 4, the light can be appropriately incident on the photoelectric conversion element 140 by increasing the arrangement position and the power of the light receiving lens 110 a. However, in this case, the size of the solar cell 100 increases.

  That is, the light guide member 120 according to the present embodiment includes the convex lens 121 and the light guide 122. Then, the emission surface 121b of the convex lens 121 is arranged in close contact with the incidence surface 122a of the light guide 122. Accordingly, the photoelectric conversion element 140 can be effectively irradiated with light in the photoelectric conversion wavelength band on the entire surface of the photoelectric conversion element 140. As a result, a small, thin, and highly efficient solar cell 100 can be realized without lowering the light use efficiency.

[2. effect]
As described above, solar cell 100 of the present embodiment includes light-receiving lens 110a having a light-condensing action, light-guiding member 120 disposed on light-emitting surface 110c side of light-receiving lens 110a, and light-emitting surface of light-guiding member 120. A glass substrate 130 is provided in contact with the light guide member 122 b, and a photoelectric conversion element 140 is provided at a position facing the light guide member 120 and receives light emitted from the glass substrate 130. The incident surface 121a of the light guide member 120 is configured as a convex surface.

  Thereby, the incident sunlight of the photoelectric conversion wavelength band can be guided to the entire surface of the photoelectric conversion element 140. As a result, light use efficiency can be improved.

(Other embodiments)
As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, and the like are made. Further, it is also possible to form a new embodiment by combining the components described in the above embodiment.

  Therefore, another embodiment will be exemplified below.

  That is, in the present embodiment, the configuration in which the area of the exit surface 121b of the convex lens 121 is equal to the area of the incident surface 122a of the light guide 122 is described as an example, but the present invention is not limited to this. For example, the area of the exit surface 121b of the convex lens 121 may be smaller than the area of the entrance surface 122a of the light guide 122.

  Specifically, in the case of a solar cell 100 configuration in which a solar tracking device is provided and the solar light is always incident in a nearly vertical state, the sun can always be arranged on the optical axis L. Therefore, the cross-sectional area of the light beam incident on the convex lens 121 can always be made smaller than the area of the incident surface 122a of the light guide unit 122 by the light condensing by the light receiving lens 110a. Thereby, the area of the exit surface 121b of the convex lens 121 can be made smaller than the area of the entrance surface 122a of the light guide 122.

  In the present embodiment, the light guide member 120 has been described as an example in which the convex lens 121 and the light guide unit 122 are configured separately, but the present invention is not limited to this. For example, the light guide member 120 may be formed by integrally forming the convex lens 121 and the light guide section 122. Accordingly, the light guide member 120 can be efficiently obtained without the step of integrating, for example, the step of bonding or the like.

  It should be noted that the above-described embodiments are intended to exemplify the technology according to the present disclosure, and thus various changes, substitutions, additions, omissions, and the like can be made within the scope of the claims or the equivalents thereof.

  The present disclosure is applicable to a concentrating solar cell used for photovoltaic power generation.

REFERENCE SIGNS LIST 100 solar cell 110 light receiving lens array 110 a light receiving lens 110 b, 121 a, 122 a, 130 a incident surface 110 c, 121 b, 122 b, 130 b emission surface 120 light guide member 121 convex lens (convex portion)
121c Vertex 122 Light guide 122c Side 130 Lath substrate (substrate)
140 Electric conversion element 150 Water film 160 Anisotropic conductive film 170 Wire substrate 180 Hot plate 200 Parallel light (parallel light)
200a Wavelength light 200b Wavelength light 200c Wavelength light FP400, FP510, FP1300, FP1300R Point position L axis

Claims (10)

A first lens made of a resin material,
A second lens for receiving light emitted from the first lens;
A multi-junction photoelectric conversion element stacked with a plurality of pn junctions;
A substrate having a light-transmitting property, which is bonded to a position where the second lens and the photoelectric conversion element face each other;
With
A plurality of the first lenses are integrally formed in an array,
The second lens and the photoelectric conversion element have a plurality of one-to-one correspondence with the first lens,
The second lens has a convex shape on the side receiving light from the first lens,
The first lens and the second lens are disposed with respect to the photoelectric conversion element based on a position of condensing light in a photoelectric conversion wavelength band of the photoelectric conversion element,
The solar cell , wherein the first lens has a convex shape having a characteristic that the shorter the wavelength of condensed light, the closer the focal point to the second lens than the photoelectric conversion element .
A focal position of the first lens at a short wavelength end of a photoelectric conversion wavelength band of the photoelectric conversion element is located closer to the first lens than the second lens.
The solar cell according to claim 1.
The focal position of the first lens at the long wavelength end of the photoelectric conversion wavelength band of the photoelectric conversion element is located closer to the photoelectric conversion element than the second lens.
The solar cell according to claim 1.
The second lens is disposed between a focal position of the first lens at a short wavelength end of a photoelectric conversion wavelength band of the photoelectric conversion element and a focal position of the first lens at a long wavelength end. ,
The solar cell according to any one of claims 1 to 3.
In the photoelectric conversion wavelength band of the photoelectric conversion element, a focal position of a wavelength at a central value of a change amount of a focal length of the first lens is located on an incident surface of the second lens.
The solar cell according to any one of claims 1 to 3.
Further comprising a light guide on the exit surface side of the second lens;
The solar cell according to claim 1.
In the second lens, a maximum cross-sectional area in a cross section perpendicular to an optical axis is equal to or less than a maximum cross-sectional area of the light guide unit.
A solar cell according to claim 6.
The light guide section has a cross-sectional shape parallel to the optical axis, a tapered shape from the light incident side to the light output side,
The solar cell according to claim 6.
Further comprising the substrate made of a resin material,
The plurality of power generation photoelectric elements are formed on a substrate,
The solar cell according to claim 1.
A first lens;
A second lens for receiving light emitted from the first lens;
a multi-junction type photoelectric conversion element that receives light condensed by the second lens;
A substrate having a light-transmitting property, which is bonded to a position where the second lens and the photoelectric conversion element face each other;
With
The second lens has a convex shape on a side that receives light emitted from the first lens,
The first lens and the second lens are disposed with respect to the photoelectric conversion element based on a position of condensing light in a photoelectric conversion wavelength band of the photoelectric conversion element,
The solar cell , wherein the first lens has a convex shape having a characteristic that the shorter the wavelength of condensed light, the closer the focal point to the second lens than the photoelectric conversion element .