JP2015159154A - Condensing photoelectric conversion apparatus and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a condensing photoelectric conversion apparatus which can be easily manufactured by using an existing solar cells available even from manufacturers other than solar cell manufacturers without newly designing a bandgap, allows a heat radiation design to be performed easily, and suppresses reduction in conversion efficiency even when light condensing magnification is increased.SOLUTION: A condensing photoelectric conversion apparatus comprises a condenser lens and a photoelectric conversion element placed at a position opposed to the condenser lens. The photoelectric conversion element consists of a solar cell for scattered light; an insulation layer provided on a surface at the condenser lens side of the solar cell for scattered light; an electrode layer provided on the insulation layer; and a solar cell for condensation, arranged on the electrode and electrically connected to the electrode layer. The condenser lens consists of a transparent thermoset resin, the photoelectric conversion element is mounted on an external connection substrate, and the solar cell for scattered light and the solar cell for condensation are electrically isolated from each other.

Description

  The present invention relates to a concentrating photoelectric conversion device and a method for manufacturing the same.

Conventionally, a photovoltaic power generation device that converts solar energy into electrical energy has been put to practical use as a photoelectric conversion device. However, in order to achieve a reduction in cost and obtain a larger amount of power generation, a condensing lens is used. A condensing photoelectric conversion device of a type that takes out electric power by irradiating condensed sunlight with a solar cell element smaller than the light receiving area of a condensing lens has been put into practical use (for example, see Patent Document 1).

However, in a conventional concentrating photoelectric conversion device, a large amount of power generation can be obtained in clear weather as compared with a flat plate solar cell module using a normal silicon solar cell, but almost no power generation amount can be obtained in cloudy weather. There was a problem.

  In order to solve the above problems, a concentrating multi-junction compound semiconductor solar cell is mounted on a scattered-light silicon solar cell, and the scattered-light silicon solar cell and the concentrating multi-junction compound semiconductor solar cell A concentrating photoelectric conversion device configured to electrically connect the two has been proposed (see Patent Document 2).

JP 2006-339522 A JP 2009-147077 A

A condensing photoelectric conversion device proposed in Patent Document 2 will be described below with reference to FIG.
In FIG. 7, the concentrating photoelectric conversion device 3 includes a silicon solar cell 100 that is a solar cell for scattered light, and a multijunction compound semiconductor solar cell 200 that is a concentrating solar cell formed on the silicon solar cell 100. And have.
The concentrating photoelectric conversion device 3 has a light receiving surface at the top, and has a condensing lens (not shown) for condensing on the multi-junction compound semiconductor solar cell 200 that is a concentrating solar cell. doing.

  The silicon solar cell 100 includes a p-type silicon substrate 113, an n-type impurity doping region 114 formed on the light-receiving surface side of the p-type silicon substrate 113, and a p-type formed on the opposite side of the light-receiving surface of the p-type silicon substrate 113. The n-type impurity doping region 114 includes a first emitter layer 114a and a second emitter layer 114b provided around the first emitter layer 114a.

An n-electrode 115 is formed on the surface of the second emitter layer 114 b, and a p-electrode 111 is formed on the surface of the p-type impurity doping region 112.
An L-shaped bonding electrode 116 is formed on the first emitter layer 114a with a partial insulating film 117 interposed therebetween.

The multi-junction compound semiconductor solar cell 200 includes a first compound semiconductor solar cell 523 on the light receiving surface side, a second compound semiconductor solar cell 524 on the opposite side to the light receiving surface, and a first compound semiconductor solar cell 523. A tunnel junction layer 518 between the second compound semiconductor solar battery 524 and the second compound semiconductor solar battery 524;
The first compound semiconductor solar cell 523 and the second compound semiconductor solar cell 524 are joined by a tunnel junction layer 518.

The first compound semiconductor solar cell 523 includes a first pn junction 525 formed of a semiconductor layer having a band gap width of 1.8 eV or more and 2 eV or less, and the first n-type compound semiconductor layer on the light receiving surface side. A stacked body 516 and a first p-type compound semiconductor layer stacked body 517 opposite to the light receiving surface are provided.
The first n-type compound semiconductor layer stack 516 is formed by stacking a plurality of n-type compound semiconductor layers, and the first p-type compound semiconductor layer stack 517 is formed by stacking a plurality of p-type compound semiconductor layers. It is formed by.

The second compound semiconductor solar cell 524 includes a second pn junction 526 formed of a semiconductor layer having a band gap width of 1.4 eV or more and 1.6 eV or less, and a second n-type compound on the light receiving surface side. It has a semiconductor layer stack 519 and a second p-type compound semiconductor layer stack 520 on the side opposite to the light receiving surface.
The second n-type compound semiconductor layer stack 519 is formed by stacking a plurality of n-type compound semiconductor layers, and the second p-type compound semiconductor layer stack 520 is formed by stacking a plurality of p-type compound semiconductor layers. Is formed.

  An n-electrode 521 is provided on the surface of the first n-type compound semiconductor layer stack 516 on the light-receiving surface side, and p is formed on the surface opposite to the light-receiving surface side of the second p-type compound semiconductor layer stack 520. An electrode 522 is provided.

  Then, the concentrating photoelectric conversion device 3 is formed by installing and electrically connecting the p-electrode 522 of the multi-junction compound semiconductor solar cell 200 on the junction electrode 116 of the silicon solar cell 100.

However, when the present inventors examined, it turned out that the condensing photoelectric conversion apparatus 3 demonstrated above has the following problems.
The first problem is that it is difficult to achieve high efficiency because it is difficult to design the band gap of each subcell (that is, the concentrating solar cell and the scattered light solar cell).
That is, two types of solar cells, a multi-junction compound semiconductor solar cell and a silicon solar cell, are used, and it is necessary to adjust the wavelength mainly absorbed by each solar cell in order to improve power generation efficiency. It is difficult to adjust which solar cell absorbs the wavelength, and as a result, the band gap design becomes difficult.
This effect is caused when the ratio of the area of the multi-junction compound semiconductor solar cell to the area of the silicon solar cell (usually less than 1) is relatively large, that is, the silicon sun that is the shadow of the multi-junction compound semiconductor solar cell. It is expected to become more prominent as the battery area increases.

The second problem is that it is difficult to manufacture except for solar cell manufacturers.
That is, 100 million units of semiconductor manufacturing equipment is required for the manufacturing equipment, and it is difficult for small companies such as small and medium-sized enterprises to make capital investments and manufacture difficult.

The third problem is that it is difficult to design heat dissipation.
That is, in the concentrating photoelectric conversion device 3 described above, the multijunction compound semiconductor solar cell 200 that is a concentrating solar cell is disposed on the silicon solar cell 100, and the heat generated by the condensing is a multijunction type. Since the generated heat diffuses from the solar cell 200 to the silicon solar cell 100, the generated heat cannot pass directly through the silicon solar cell 100, so that the heat dissipation design becomes difficult. It is.

The fourth problem is that the conversion efficiency of the silicon solar cell is likely to be lowered due to a temperature rise, so that the light collecting magnification cannot be increased.
That is, the heat generated mainly in the multi-junction compound semiconductor solar cell 200 due to the light condensing diffuses into the silicon solar cell 100. Therefore, when the light condensing magnification is increased, the conversion efficiency is increased due to the temperature rise of the silicon solar cell 100. A decrease occurs.
Moreover, since local high temperature causes stress distribution in the silicon solar cell, there is a problem from the viewpoint of long-term reliability.

  The present invention has been made in view of the above problems, and does not require a new band gap design, and can be easily manufactured using an existing solar cell that can be obtained by other than a solar cell manufacturer. An object of the present invention is to provide a condensing photoelectric conversion device that is easy to design for heat dissipation and can suppress a decrease in conversion efficiency even when the condensing magnification is increased.

  In order to achieve the above object, the present invention is a condensing photoelectric conversion device comprising a condensing lens and a photoelectric conversion element installed at a position facing the condensing lens, the photoelectric conversion element Are provided on the electrode layer, a solar cell for scattered light, an insulating layer provided on the surface of the solar cell for scattered light on the condenser lens side, an electrode layer provided on the insulating layer, and A concentrating solar cell electrically connected to the electrode layer, the condensing lens is made of a transparent thermosetting resin, and the photoelectric conversion element is mounted on an external connection substrate, The concentrating photoelectric conversion device is characterized in that the scattered light solar cell and the concentrating solar cell are electrically separated.

Thus, the concentrating solar cell is provided on the scattered light solar cell via the insulating layer, and the concentrating solar cell is electrically connected to the electrode layer on the insulating layer, Since the solar cell is configured to be mounted on the external connection substrate, a concentrating photoelectric conversion device can be obtained by using an existing concentrating solar cell and an existing scattered light solar cell in combination. In addition, it is not necessary to design a band cap, and it can be easily manufactured by anyone other than a solar cell manufacturer.
In addition, since the concentrating solar cell is provided on the insulating layer via the electrode layer, the heat generated in the concentrating solar cell can be directly diffused into the insulating layer. The heat diffusion can be prevented, and the heat radiation design can be facilitated.

At this time, the scattered light solar cell and the concentrating solar cell are a single crystal silicon type, polycrystalline silicon type, thin film silicon type, HIT type, CIGS type, CdTe type, dye sensitized type, organic semiconductor type, III It can be composed of at least one of -V group multi-junction type.
Thus, the solar cell of the above type can be suitably used as the solar cell for scattered light and the solar cell for condensing light.

At this time, the transparent thermosetting resin is preferably a material containing silicone.
As the transparent thermosetting resin constituting the condenser lens, a material containing silicone can be suitably used.

At this time, the insulating layer is preferably made of a thermosetting resin or glass.
As the insulating layer that electrically separates the scattered light solar cell and the concentrating solar cell, the above materials can be suitably used.

At this time, the insulating layer preferably includes at least one of a light scattering preventing material, a phosphor, a quantum dot, and an anti-settling agent.
With such a configuration, the power generation efficiency of the scattering solar cell can be improved.

At this time, it is preferable to have a reflection layer that reflects or scatters the light transmitted through the scattered light solar cell on the external connection substrate side of the scattered light solar cell.
With such a configuration, the power generation efficiency of the scattering solar cell can be improved.

The condensing lens and the photoelectric conversion element are preferably integrally molded and sealed with a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm.
With such a configuration, it is possible to improve the moisture resistance of the photoelectric conversion element while maintaining the power generation efficiency of the scattering solar cell and the concentrating solar cell.

  Further, the present invention is a condensing photoelectric conversion device comprising a condensing lens and a photoelectric conversion element installed at a position facing the condensing lens, wherein the photoelectric conversion element is a silicon solar cell. , An insulating layer having a thickness of 0.1 to 100 μm provided on the surface of the silicon solar cell on the condenser lens side, an electrode layer provided on the insulating layer, and the electrode provided on the electrode layer A III-V multi-junction solar cell electrically connected to the layer, and the insulating layer includes a silicone resin, or a glassy material formed from a material mainly composed of polysilazanes. The concentrating photoelectric conversion device is characterized in that the silicon solar cell and the III-V multi-junction solar cell are electrically separated.

Thus, the group III-V multi-junction solar cell that is a concentrating solar cell is provided on the silicon solar cell that is a scattered light solar cell via an insulating layer, and the group III-V Since the junction solar cell is electrically connected to the electrode layer on the insulating layer and the silicon solar cell is mounted on the external connection substrate, the existing III-V group multi-junction solar cell and the existing If it is used in combination with a silicon solar cell, it becomes a condensing photoelectric conversion device, so that it is not necessary to newly design a band cap, and it can be easily manufactured by a non-solar cell manufacturer.
In addition, since the III-V group multi-junction solar cell is provided on the insulating layer, the heat generated in the group III-V multi-junction solar cell can be directly diffused into the insulating layer. The diffusion of heat to the silicon solar cell can be prevented, the decrease in power generation efficiency of the silicon solar cell can be suppressed, and the heat dissipation design can be facilitated.

  Moreover, this invention is a method of manufacturing said condensing type photoelectric conversion apparatus, Comprising: After integrating the said photoelectric conversion element with the said external connection board | substrate, using a type | mold, it is said transparent thermosetting resin. A condensing photoelectric conversion device manufacturing method is provided, wherein a condensing lens is formed on a surface of the photoelectric conversion element opposite to the external connection substrate.

  The condensing lens of said condensing type photoelectric conversion apparatus can be manufactured using such a manufacturing method.

At this time, the insulating layer can be formed by at least one of film bonding, spin coating, spraying, printing, and molding by a mold.
When forming the insulating layer for electrically separating the solar cell for scattered light and the solar cell for condensing light, the above manufacturing method can be suitably used.

At this time, the condenser lens and the photoelectric conversion element are cast, transfer molding, compression molding, using a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm, It is preferable to integrally mold and seal by at least one of injection molding.
When the condenser lens and the photoelectric conversion element are integrally molded and sealed, the above manufacturing method can be suitably used.

At this time, the electrode layer can be formed by at least one of film bonding, spin coating, spraying, printing, and vapor deposition.
When forming the electrode layer electrically connected to the concentrating solar cell, the above manufacturing method can be suitably used.

  In addition, the present invention is a method for manufacturing the above-described concentrating photoelectric conversion device, wherein the photoelectric conversion element is integrated with an external connection substrate, and then photoelectric conversion is performed using a material including a transparent silicone resin that is placed in a mold. Provided is a method of manufacturing a condensing photoelectric conversion device, wherein the condensing lens is molded and cured on a surface of an element opposite to the external connection substrate.

  The condensing lens of said condensing type photoelectric conversion apparatus can be manufactured using such a manufacturing method.

As described above, according to the present invention, the concentrating solar cell is provided on the scattered light solar cell via the insulating layer, and the concentrating solar cell is electrically connected to the electrode layer on the insulating layer. If the existing concentrating solar cell and the existing scattered light solar cell are used in combination, the concentrating photoelectric conversion is performed. Since it becomes an apparatus, it is not necessary to newly design a band cap, and it can be easily manufactured by anyone other than a solar cell manufacturer.
Further, according to the present invention, since the concentrating solar cell is provided on the insulating layer via the electrode layer, the heat generated in the concentrating solar cell can be directly diffused into the insulating layer. It is possible to prevent the diffusion of heat to the scattered light solar cell and to facilitate the heat dissipation design.

It is sectional drawing and perspective view which show the condensing type photoelectric conversion apparatus of this invention. It is sectional drawing which shows the condensing lens of the condensing type photoelectric conversion apparatus of this invention. It is sectional drawing and the perspective view which show the specific example of the condensing type photoelectric conversion apparatus of this invention. It is sectional drawing which shows the condensing lens of the specific example of the condensing type photoelectric conversion apparatus of this invention. It is sectional drawing to which the III-V group multijunction solar cell of the specific example of the condensing type photoelectric conversion apparatus of this invention was expanded. 6 is a cross-sectional view showing a condensing photoelectric conversion device of Comparative Example 1. FIG. It is sectional drawing which shows the conventional condensing type photoelectric conversion apparatus.

  Hereinafter, the present invention will be described in detail as an example of an embodiment with reference to the drawings, but the present invention is not limited thereto.

As described above, the concentrating photoelectric conversion device proposed in Patent Document 2 has the following problems.
The first problem is that it is difficult to achieve high efficiency because it is difficult to design the band gap of each subcell (that is, the concentrating solar cell and the scattered light solar cell).
The second problem is that it is difficult to manufacture except for solar cell manufacturers.
The third problem is that it is difficult to design heat dissipation.
The fourth problem is that the conversion efficiency of the silicon solar cell is likely to be lowered due to a temperature rise, so that the light collecting magnification cannot be increased.

Therefore, the present inventors do not need to newly design a band gap, and can be easily manufactured by a non-solar cell manufacturer, easy to design for heat dissipation, and decrease in conversion efficiency even if the light collection magnification is increased. We have made extensive studies on a concentrating photoelectric conversion device that can suppress the above.
As a result, the concentrating solar cell is provided on the scattered light solar cell via the insulating layer, the concentrating solar cell is electrically connected to the electrode layer on the insulating layer, and the scattered light solar cell is externally provided. By adopting a configuration to be mounted on the connection substrate, a concentrating photoelectric conversion device can be obtained by using a combination of an existing concentrating solar cell and an existing scattered light solar cell. It is not necessary and can be easily manufactured by non-solar cell manufacturers. Furthermore, since the concentrating solar cell is provided on the insulating layer via the electrode layer, the heat generated by the concentrating solar cell can be reduced. Since it can be diffused in the insulating layer, it has been found that heat can be prevented from diffusing into the solar cell for scattered light, and heat radiation design can be facilitated, and the present invention has been made.

Hereinafter, the condensing photoelectric conversion device of the present invention will be described with reference to FIGS.
FIG. 1A shows a cross-sectional view of the concentrating photoelectric conversion device 1 of the present invention, and FIG. 1B shows a perspective view of the condensing photoelectric conversion device 1 of the present invention. These show sectional views showing the condensing lens 34 of the condensing photoelectric conversion apparatus 1 of the present invention.

In FIG. 1, the concentrating photoelectric conversion device 1 includes a scattered light solar cell 10, an insulating layer 31 provided on the surface of the scattered light solar cell 10 on the condensing lens 34 side (see FIG. 2), The photoelectric conversion element 30 includes an electrode layer 32 provided on the insulating layer 31 and a concentrating solar cell 20 provided on the electrode layer 32 and electrically connected to the electrode layer 32.
The condensing photoelectric conversion device 1 has a light receiving surface at the top, and a condensing lens 34 (see FIG. 2) made of a transparent thermosetting resin that condenses on the concentrating solar cell 20 at the top. Have.

The scattered light solar cell 10 constituting the photoelectric conversion element 30 is mounted on an external connection substrate 41 including a base 42 and an external connection wiring 43, and is connected to the outside via the external connection substrate 41.
The concentrating solar cell 20 is provided on the insulating layer 31 via the electrode layer 32 and is connected to the outside via the electrode layer 32.

In the concentrating photoelectric conversion device 1 of the present invention, the concentrating solar cell 20 is provided on the scattered light solar cell 10 via an insulating layer, and the concentrating solar cell 20 is on the insulating layer 31. Since the scattered light solar cell 10 is electrically connected to the electrode layer 32 and mounted on the external connection substrate 41, the existing concentrating solar cell and the existing scattered light solar cell are combined. When used in combination, it becomes a condensing photoelectric conversion device, so that it is not necessary to newly design a band cap, and it can be easily manufactured by anyone other than a solar cell manufacturer.
Moreover, since the concentrating solar cell 20 is provided on the insulating layer 31 via the electrode layer 32, the heat generated in the concentrating solar cell 20 can be directly diffused into the insulating layer 31, and thus the scattering. The heat diffusion to the solar cell for light 10 can be prevented and the heat radiation design can be facilitated.

The scattered light solar cell 10 and the concentrating solar cell 20 are a single crystal silicon type, polycrystalline silicon type, thin film silicon type, HIT type, CIGS type, CdTe type, dye sensitized type, organic semiconductor type, III-V. It can be composed of at least one of the multi-family type.
Thus, the solar cell of the above type can be suitably used as the solar cell for scattered light and the solar cell for condensing light.

The transparent thermosetting resin constituting the condenser lens 34 is preferably a material containing silicone.
As the transparent thermosetting resin constituting the condenser lens, a material containing silicone can be suitably used.

The insulating layer 31 is preferably made of a thermosetting resin or glass.
As the insulating layer 31 that electrically separates the scattered light solar cell and the concentrating solar cell, the above materials can be suitably used.

The insulating layer 31 preferably contains at least one of a light scattering preventing material, a phosphor, a quantum dot, and an anti-settling agent.
With such a configuration, the power generation efficiency of the scattering solar cell 10 can be improved.

It is preferable to have a reflective layer on the external connection substrate 41 side of the scattered light solar cell 10 to reflect or scatter the light transmitted through the scattered light solar cell 10.
With such a configuration, the power generation efficiency of the scattering solar cell 10 can be improved.

It is preferable that the condenser lens 34 and the photoelectric conversion element 30 are integrally molded and sealed with a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm.
With such a configuration, the moisture resistance of the photoelectric conversion element 30 can be improved while maintaining the power generation efficiency of the scattering solar cell 10 and the concentrating solar cell 20.

After integrating the photoelectric conversion element 30 with the external connection substrate 41, the condenser lens 34 is formed on the surface opposite to the external connection substrate 41 of the photoelectric conversion element 30 with a transparent thermosetting resin using a mold. Can do.
The condensing lens 34 of the condensing photoelectric conversion apparatus 1 can be manufactured using such a manufacturing method.

The insulating layer 31 can be formed by at least one of film bonding, spin coating, spraying, printing, and molding with a mold.
When forming the insulating layer 31 which electrically isolate | separates the solar cell 10 for scattered light and the solar cell 20 for condensing, the above manufacturing methods can be used suitably.

The condenser lens 34 and the photoelectric conversion element 30 are cast, transfer molded, compression molded, or injection molded using a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm. It is preferable to integrally mold and seal with at least one or more.
When the condenser lens 34 and the photoelectric conversion element 30 are integrally molded and sealed, the above manufacturing method can be suitably used.

The electrode layer 32 can be formed by at least one of film bonding, spin coating, spraying, printing, and vapor deposition.
When the electrode layer 32 electrically connected to the concentrating solar cell 20 is formed, the above manufacturing method can be suitably used.

  Next, referring to FIGS. 3 to 5, in the concentrating photoelectric conversion device 1 of the present invention, a silicon solar cell 10 ′ is used as a solar cell for scattered light, and a group III-V is used as a concentrating solar cell. The condensing photoelectric conversion apparatus 2 using the junction solar cell 20 ′ will be described.

  3A shows a cross-sectional view of the condensing photoelectric conversion device 2 of the present invention, and FIG. 3B shows a perspective view of the condensing photoelectric conversion device 2 of the present invention. FIG. 5 shows a cross-sectional view of the condensing lens 34 of the condensing photoelectric conversion device 2 of the present invention, and FIG. 5 shows an enlarged cross-sectional view of the III-V group multi-junction solar cell 20 ′.

In FIG. 3, the concentrating photoelectric conversion device 2 includes a silicon solar cell 10 ′, an insulating layer 31 provided on the surface of the silicon solar cell 10 ′ on the condensing lens 34 side (see FIG. 4), and an insulating layer. A photoelectric conversion element 30 including an electrode layer 32 provided on the electrode 31 and a group III-V multi-junction solar cell 20 ′ provided on the electrode layer 32 and electrically connected to the electrode layer 32. Yes.
The condensing photoelectric conversion device 2 has a light receiving surface at the top, and a condensing lens 34 (FIG. 4) made of a transparent thermosetting resin that condenses on the III-V multijunction solar cell 20 ′. At the top.

The silicon solar cell 10 ′ constituting the photoelectric conversion element 30 is mounted on an external connection substrate 41 including a base body 42 and external connection wirings 43, and is connected to the outside via the external connection substrate 41.
The III-V group multi-junction solar cell 20 ′ is provided on the insulating layer 31 through the electrode layer 32, and is connected to the outside through the electrode layer 32.

  The insulating layer 31 includes a silicone resin, or includes a glass material formed from a material containing polysilazanes as a main component.

  The silicon solar cell 10 ′ is formed on the p-type silicon substrate 13, the n-type impurity doping region 14 formed on the condensing lens 34 side of the p-type silicon substrate 13, and the external connection substrate 41 side of the p-type silicon substrate 13. P-type impurity doping region 12 formed.

An n-electrode 15 is formed on the surface of the n-type impurity doping region 14, and a p-electrode 11 is formed on the surface of the p-type impurity doping region 12.
And silicon solar cell 10 'is electrically connected to the external connection board | substrate 41 so that the p electrode 11 and the external connection wiring 43 may contact | connect.

The group III-V multi-junction solar cell 20 'includes a first group III-V compound semiconductor solar cell 28 on the condenser lens 34 side and a second group III-V compound semiconductor solar on the external connection substrate 41 side. The battery 27 includes a tunnel junction layer 24 between the first III-V compound semiconductor solar battery 28 and the second III-V compound semiconductor solar battery 27.
The first III-V group compound semiconductor solar cell 28 and the second III-V group compound semiconductor solar cell 27 are joined by a tunnel junction layer 24.
For example, as shown in FIG. 5, the tunnel junction layer 24 includes a p-type AlGaAs tunnel junction layer 24a and an n-type AlInGaP tunnel junction layer 24b.

The first III-V compound semiconductor solar cell 28 includes a first pn junction 35 formed by a semiconductor layer having a band gap width of 1.8 eV or more and 2 eV or less, and the first III-V compound semiconductor solar cell 28 on the condenser lens 34 side. N-type group III-V compound semiconductor layer stack 26 and a first p-type group III-V compound semiconductor layer stack 25 on the external connection substrate 41 side.
The first n-type III-V compound semiconductor layer stack 26 is formed by stacking a plurality of n-type III-V compound semiconductor layers. For example, as shown in FIG. 5, an n-type GaAs contact layer is formed. 26a, an n-type AlInP window layer 26b, and an n-type AlInGaP emitter layer 26c.
The first p-type III-V compound semiconductor layer stack 25 is formed by stacking a plurality of p-type compound semiconductor layers. For example, as shown in FIG. 5, a p-type AlInGaP base layer 25a, p It consists of a type AlInP back surface field layer 25b.

The second III-V compound semiconductor solar battery 27 includes a second pn junction 36 formed by a semiconductor layer having a band gap width of 1.4 eV or more and 1.6 eV or less, and is arranged on the condenser lens 34 side. The second n-type III-V compound semiconductor layer stack 23 and the second p-type III-V compound semiconductor layer stack 22 on the external connection substrate 41 side are provided.
The second n-type group III-V compound semiconductor layer stack 23 is formed by stacking a plurality of n-type group III-V compound semiconductor layers. For example, as shown in FIG. 5, an n-type AlInP window layer is formed. 23a and an n-type AlGaAs emitter layer 23b.
The second p-type group III-V compound semiconductor layer stack 22 is formed by stacking a plurality of p-type group III-V compound semiconductor layers. For example, as shown in FIG. 5, a p-type AlGaAs base layer is formed. 22a, a p-type InGaP back surface field layer 22b, and a p-type GaAs contact layer 22c.

An n-electrode 29 is provided on the light receiving surface side surface of the first n-type III-V compound semiconductor layer stack 26, and external connection of the second p-type III-V compound semiconductor layer stack 22 is performed. A p-electrode 21 is provided on the surface on the substrate 41 side.
The III-V group multi-junction solar cell 20 ′ is provided on the insulating layer 31 so that the p-electrode 21 and the electrode layer 32 are in contact with each other.

In the concentrating photoelectric conversion device 2 of the present invention, a group III-V multi-junction solar cell 20 ′ is provided on a silicon solar cell 10 ′ via an insulating layer, and a group III-V multi-junction solar cell is obtained. The battery 20 ′ is electrically connected to the electrode layer 32 on the insulating layer 31, and the silicon solar battery 10 ′ is mounted on the external connection substrate 41. If the solar cell for scattered light is used in combination, it becomes a condensing photoelectric conversion device, so that it is not necessary to newly design a band cap, and it can be easily manufactured by a manufacturer other than the solar cell manufacturer.
Further, since the III-V group multi-junction solar cell 20 ′ is provided on the insulating layer 31 via the electrode layer 32, the heat generated in the III-V group multi-junction solar cell 20 ′ is directly generated by the insulating layer. Therefore, it is possible to prevent heat from diffusing into the silicon solar cell 10 ′, to suppress a decrease in power generation efficiency of the silicon solar cell 10 ′, and to facilitate heat dissipation design.

After the photoelectric conversion element 30 is integrated with the external connection substrate 41, a condensing lens 34 is molded and cured on the surface opposite to the external connection substrate 41 of the photoelectric conversion element 30 using a material containing a transparent silicone resin using a mold. Can be made.
The condensing lens 34 of the condensing photoelectric conversion apparatus 2 can be manufactured using such a manufacturing method.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these.

Example 1
First, the silicon solar cell 10 ′ was mounted on the PCB substrate as the external connection substrate 41 using a solder paste, and UV ozone treatment was performed.
Next, a silicone resin (AF-500: manufactured by Shin-Etsu Chemical Co., Ltd.) coated in a film shape on the surface of the silicon solar cell 10 ′ is attached with a vacuum laminator device (manufactured by Nichigo Morton) to produce the insulating layer 31. did.
Next, Ag paste (manufactured by Shin-Etsu Chemical Co., Ltd.) was screen-printed on the insulating layer 31 to produce an electrode layer 32 on which a III-V group multi-junction solar cell 20 ′, which is a concentrating solar cell, is mounted.
After producing the electrode layer, a III-V group multi-junction solar cell 20 ′, which is a concentrating solar cell, was mounted using lead-free solder.
Next, the photoelectric conversion element 30 mounted on the external connection substrate 41 is placed in a mold, and the condenser lens 34 and the external connection substrate 41 are held by compression molding of a silicone resin (LPS-3541 manufactured by Shin-Etsu Chemical Co., Ltd.). The photoelectric conversion element 30 was integrally molded to produce the condensing photoelectric conversion device 2.

(Example 2)
First, the silicon solar cell 10 ′ was mounted on the PCB substrate as the external connection substrate 41 using a solder paste, and UV ozone treatment was performed.
Next, a film made by mixing a silicone resin (AF-500: manufactured by Shin-Etsu Chemical Co., Ltd.) and a phosphor on the surface of the silicon solar cell 10 'is pasted with a vacuum laminator apparatus (manufactured by Nichigo Morton), thereby insulating 50 μm Layer 31 was made.
Next, Ag paste was screen-printed on the insulating layer 31 to produce an electrode layer 32 on which a III-V group multi-junction solar cell 20 ′, which is a concentrating solar cell, is mounted.
After producing the electrode layer, a III-V group multi-junction solar cell 20 ′, which is a concentrating solar cell, was mounted using lead-free solder.
Next, the photoelectric conversion element 30 connected to the external connection substrate 41 is placed in a mold, and the condenser lens 34 and the external connection substrate 41 are held by compression molding of a silicone resin (LPS-3541 manufactured by Shin-Etsu Chemical Co., Ltd.). The condensing photoelectric conversion device 2 was produced by integrally molding the photoelectric conversion element 30 to be formed.

(Comparative Example 1)
The condensing photoelectric conversion device 4 of Comparative Example 1 will be described with reference to FIG.
First, the silicon solar cell 10 ′ was mounted on a PCB substrate which is an external connection substrate 41 composed of a base 42 and external connection wirings 43 using a solder paste, and UV ozone treatment was performed.
Next, Ag paste (manufactured by Shin-Etsu Chemical Co., Ltd.) is screen-printed on the surface of the silicon solar cell 10 ', and an electrode layer 32 on which the III-V group multi-junction solar cell 20' that is a concentrating solar cell is mounted is produced. did.
After producing the electrode layer 32, a III-V group multi-junction solar cell 20 ′, which is a concentrating solar cell, was mounted using lead-free solder.
Next, the photoelectric conversion element 30 mounted on the external connection substrate 41 is placed in a mold, and the condenser lens 34 and the external connection substrate 41 are held by compression molding of a silicone resin (LPS-3541 manufactured by Shin-Etsu Chemical Co., Ltd.). The photoelectric conversion element 30 was integrally molded to produce the condensing photoelectric conversion device 4.

For each of the concentrating photoelectric conversion devices 2 of Examples 1 and 2, the total power generation efficiency at room temperature of 25 ° C. was measured using actual sunlight.
Furthermore, the power generation efficiency was measured in the same manner for silicon solar cells and III-V multi-junction solar cells. The power generation efficiency is defined by (electric output from solar cell / solar energy entering solar cell) × 100 (%).
The results are shown in Table 1.

  As can be seen from Table 1, in the concentrating photoelectric conversion devices of Examples 1 and 2 manufactured by combining an existing silicon solar cell and an existing III-V group multi-junction solar cell, the silicon solar cell, III The power generation efficiency could be dramatically improved as compared with the use of the −V group multi-junction solar cell alone.

Moreover, the total power generation efficiency 30 minutes after the start of the test and the junction temperature of the silicon solar cell were measured for each of the concentrating photoelectric conversion devices 2 of Examples 1 and 2 using actual sunlight.
Further, the same measurement was performed for the condensing photoelectric conversion device 4 of Comparative Example 1.
The results are shown in Table 2.

  As can be seen from Table 2, in Example 1-2 in which an insulating layer was provided between the silicon solar cell and the III-V group multi-junction solar cell, the group III-V multi-junction type solar cell directly on the silicon solar cell. Compared with the concentrating photoelectric conversion device 4 of Comparative Example 1 in which the batteries are stacked, the influence of the heat generation of the III-V group multi-junction solar cell on the silicon solar cell is suppressed, and the junction temperature of the silicon solar cell is large. Does not rise. As a result, the decrease in power generation efficiency due to the increase in junction temperature can be maintained within 10%, and it has been found that there is no problem with heat dissipation.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

1, 2, 3 ... Condensing photoelectric conversion device,
10 ... solar cell for scattered light, 10 '... silicon solar cell (solar cell for scattered light),
11 ... p electrode, 12 ... p-type impurity doping region, 13 ... p-type silicon substrate,
14 ... n-type impurity doping region, 15 ... n-electrode,
20 ... Concentrating solar cell,
20 '... III-V group multi-junction solar cell (condensing solar cell), 21 ... p-electrode,
22 ... Second p-type III-V compound semiconductor layer stack,
22a ... p-type AlGaAs base layer, 22b ... p-type InGaP back surface field layer,
22c ... p-type GaAs contact layer,
23. Second n-type III-V compound semiconductor layer stack,
23a ... n-type AlInP window layer, 23b ... n-type AlGaAs emitter layer,
24 ... tunnel junction layer, 24a ... p-type AlGaAs tunnel junction layer,
24b ... n-type AlInGaP tunnel junction layer,
25. First p-type group III-V compound semiconductor layer stack,
25a ... p-type AlInGaP base layer, 25b ... p-type AlInP back surface field layer,
26. First n-type III-V compound semiconductor layer stack,
26a ... n-type GaAs contact layer, 26b ... n-type AlInP window layer,
26c ... n-type AlInGaP emitter layer,
27. Second group III-V compound semiconductor solar cell,
28 ... 1st group III-V compound semiconductor solar cell, 29 ... n electrode,
30 ... Photoelectric conversion element, 31 ... Insulating layer, 32 ... Electrode layer, 34 ... Condensing lens,
35 ... 1st pn junction, 36 ... 2nd pn junction,
41 ... External connection substrate, 42 ... Base, 43 ... External connection wiring,
100 ... silicon solar cell (condensing photoelectric conversion device), 111 ... p-electrode,
112 ... p-type impurity doping region, 113 ... p-type silicon substrate,
114 ... n-type impurity doping region, 114a ... first emitter layer,
114b ... second emitter layer, 115 ... n electrode, 116 ... junction electrode,
117: Insulating film,
200 ... multi-junction compound semiconductor solar cell (concentrator solar cell),
516 ... First n-type compound semiconductor layer stack,
517: First p-type compound semiconductor layer stack, 518: Tunnel junction layer,
519 ... second n-type compound semiconductor layer stack,
520 ... 2nd p-type compound semiconductor layer laminated body, 521 ... n electrode, 522 ... p electrode,
523 ... 1st compound semiconductor solar cell, 524 ... 2nd compound semiconductor solar cell,
525 ... first pn junction, 526 ... second pn junction.

The third problem is that it is difficult to design heat dissipation.
That is, in the concentrating photoelectric conversion device 3 described above, the multijunction compound semiconductor solar cell 200 that is a concentrating solar cell is disposed on the silicon solar cell 100, and the heat generated by the condensing is a multijunction type. Since the compound semiconductor solar cell 200 diffuses from the silicon solar cell 100 to the silicon solar cell 100, the generated heat cannot pass directly through the silicon solar cell 100, so that the heat dissipation design becomes difficult. That's it.

In FIG. 1, the concentrating photoelectric conversion device 1 includes a scattered light solar cell 10, an insulating layer 31 provided on the surface of the scattered light solar cell 10 on the condensing lens 34 side (see FIG. 2), The photoelectric conversion element 30 includes an electrode layer 32 provided on the insulating layer 31 and a concentrating solar cell 20 provided on the electrode layer 32 and electrically connected to the electrode layer 32.
The condensed type photoelectric conversion device 1, the upper has become a light-receiving surface, a transparent thermosetting resin from ing a condenser lens 34 (see FIG. 2) upper condensed on converging solar cell 20 Have.

Claims (13)

A condensing photoelectric conversion device comprising a condensing lens and a photoelectric conversion element installed at a position facing the condensing lens,
The photoelectric conversion element includes a solar cell for scattered light, an insulating layer provided on the condenser lens side surface of the solar cell for scattered light, an electrode layer provided on the insulating layer, and the electrode layer A concentrating solar cell provided on and electrically connected to the electrode layer;
The condenser lens is made of a transparent thermosetting resin,
The photoelectric conversion element is mounted on an external connection substrate,
The concentrating photoelectric conversion device, wherein the scattered light solar cell and the concentrating solar cell are electrically separated.   The solar cell for scattered light and the solar cell for concentrating light are monocrystalline silicon type, polycrystalline silicon type, thin film silicon type, HIT type, CIGS type, CdTe type, dye sensitized type, organic semiconductor type, III-V The condensing photoelectric conversion device according to claim 1, wherein the concentrating photoelectric conversion device is composed of at least one of a group multi-junction type.   The condensing photoelectric conversion device according to claim 1, wherein the transparent thermosetting resin is a material containing silicone.   The condensing photoelectric conversion device according to any one of claims 1 to 3, wherein the insulating layer is made of a thermosetting resin or glass.   4. The concentrating photoelectric device according to claim 1, wherein the insulating layer includes at least one of a light scattering preventing material, a phosphor, a quantum dot, and an anti-settling agent. 5. Conversion device.   6. The reflective layer for reflecting or scattering light transmitted through the solar cell for scattered light is provided on an external connection substrate side of the solar cell for scattered light. 6. The condensing photoelectric conversion device described in 1.   The condensing lens and the photoelectric conversion element are integrally molded and sealed with a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm. The condensing photoelectric conversion device according to any one of claims 1 to 6. A condensing photoelectric conversion device comprising a condensing lens and a photoelectric conversion element installed at a position facing the condensing lens,
The photoelectric conversion element includes a silicon solar cell, an insulating layer having a thickness of 0.1 to 100 μm provided on the surface of the silicon solar cell on the condenser lens side, and an electrode layer provided on the insulating layer. A III-V group multi-junction solar cell provided on the electrode layer and electrically connected to the electrode layer;
The insulating layer includes a silicone resin, or includes a glassy material formed from a material mainly containing polysilazanes,
The concentrating photoelectric conversion device, wherein the silicon solar cell and the group III-V multi-junction solar cell are electrically separated. A method for producing the concentrating photoelectric conversion device according to any one of claims 1 to 7,
After integrating the photoelectric conversion element with the external connection substrate, using a mold, a condenser lens is formed on the surface of the photoelectric conversion element opposite to the external connection substrate with the transparent thermosetting resin. A method of manufacturing a condensing photoelectric conversion device characterized by the above.   The method for manufacturing a concentrating photoelectric conversion device according to claim 9, wherein the insulating layer is formed by at least one of film bonding, spin coating, spraying, printing, and molding using a mold.   The condensing lens and the photoelectric conversion element are cast, transfer molded, compression molded, or injection molded using a transparent thermosetting resin having a light transmittance of 80% or more in a wavelength range of 400 nm to 800 nm. The method for producing a concentrating photoelectric conversion device according to claim 9 or 10, wherein at least one or more are integrally molded and sealed.   The condensing photoelectric conversion according to any one of claims 9 to 11, wherein the electrode layer is formed by at least one of film bonding, spin coating, spraying, printing, and vapor deposition. Device manufacturing method. A method for producing the concentrating photoelectric conversion device according to claim 8,
After the photoelectric conversion element is integrated with the external connection substrate, the condenser lens is molded and cured on the surface of the photoelectric conversion element opposite to the external connection substrate with a material including a transparent silicone resin that is placed in a mold. A manufacturing method of a condensing photoelectric conversion device, which is characterized.

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