WO2018225361A1 - Photovoltaic generation element - Google Patents

Photovoltaic generation element Download PDF

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Publication number
WO2018225361A1
WO2018225361A1 PCT/JP2018/014309 JP2018014309W WO2018225361A1 WO 2018225361 A1 WO2018225361 A1 WO 2018225361A1 JP 2018014309 W JP2018014309 W JP 2018014309W WO 2018225361 A1 WO2018225361 A1 WO 2018225361A1
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Prior art keywords
photoelectric conversion
conversion cell
layer
electrode
cell
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PCT/JP2018/014309
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French (fr)
Japanese (ja)
Inventor
岩崎　孝
和正 鳥谷
充 稲垣
斉藤　健司
義哉 安彦
永井　陽一
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住友電気工業株式会社
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Publication of WO2018225361A1 publication Critical patent/WO2018225361A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier
    • H01L31/068—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
    • H01L31/0687—Multiple junction or tandem solar cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/544—Solar cells from Group III-V materials

Definitions

  • the present invention relates to a photovoltaic device.
  • This application claims priority based on Japanese Patent Application No. 2017-113100 filed on June 8, 2017, and incorporates all the description content described in the above Japanese application.
  • Patent Document 1 discloses a three-junction solar cell element in which a Ge cell, a GaAs cell, and an AlInGaP cell are joined by a tunnel junction layer.
  • the photovoltaic device which is one embodiment is a photovoltaic device including at least a first photoelectric conversion cell and a second photoelectric conversion cell, wherein the first photoelectric conversion cell, the second photoelectric conversion cell, Are stacked via an insulating layer that insulates the first photoelectric conversion cell from the second photoelectric conversion cell.
  • FIG. 1 is a plan view of the photovoltaic device according to the first embodiment.
  • FIG. 2 is a diagram showing a part of a cross section taken along line II-II in FIG.
  • FIG. 3A is a diagram for explaining a method for manufacturing a photovoltaic device, and is a partial cross-sectional view of a Ge substrate used for the photovoltaic device 1
  • FIG. 3B is a diagram of a first stacked body in which each semiconductor layer is formed.
  • FIG. 3C is a partial cross-sectional view of the first stacked body after etching.
  • FIG. 4A is a diagram for explaining another method for manufacturing a photovoltaic device, and is a partial cross-sectional view of a laminated body corresponding to each photoelectric conversion cell, and FIG.
  • FIG. 4B is obtained by joining the laminated bodies. It is a partial sectional view of the 1st layered product.
  • FIG. 5 is a plan view of the photovoltaic device according to the second embodiment.
  • FIG. 6 is a diagram showing a part of a cross section taken along line VI-VI in FIG.
  • each cell is bonded and laminated by a tunnel junction layer, and power is supplied from a surface electrode provided on the surface of the solar cell element and a back electrode provided on the back surface of the solar cell element.
  • a surface electrode provided on the surface of the solar cell element
  • a back electrode provided on the back surface of the solar cell element.
  • the sunlight that reaches the solar cell element increases or decreases due to changes in the surrounding environment such as changes in solar altitude due to time and season, atmospheric conditions, and the presence of aerosols. For this reason, the current output from each cell varies depending on changes in the surrounding environment. At this time, the components in the short wavelength region among the components contained in the sunlight are greatly affected by changes in the surrounding environment, and therefore, relative to the components in other wavelength regions before reaching the solar cell element. May decrease significantly.
  • the amount of decrease in current value due to changes in the surrounding environment is relatively greater than the amount of decrease in current value of other cells. Therefore, the difference between the currents output by each cell increases, and the power generation efficiency of the entire multi-junction solar cell element may decrease.
  • each cell is connected in series, so that the current value of the entire photovoltaic device is the smallest current value among the current values output by each cell. Therefore, power generation efficiency may be reduced due to environmental changes.
  • the present disclosure has been made in view of such circumstances, and an object thereof is to provide a photovoltaic device capable of suppressing a decrease in power generation efficiency.
  • a photovoltaic device is a photovoltaic device including at least a first photoelectric conversion cell and a second photoelectric conversion cell, wherein the first photoelectric conversion cell and the second photoelectric conversion cell are included.
  • the conversion cell is laminated through an insulating layer that insulates the first photoelectric conversion cell and the second photoelectric conversion cell.
  • the first photoelectric conversion cell and the second photoelectric conversion cell are stacked via the insulating layer, the first photoelectric conversion cell and the second photoelectric conversion cell are independently photovoltaic. It can be used as an element. As a result, the first photoelectric conversion cell and the second photoelectric conversion cell can be connected in parallel, or can be connected to independent paths. Thereby, it is possible to output current in an optimal state for each cell. As a result, it is possible to suppress a decrease in power generation efficiency as a whole photovoltaic power generation element.
  • a p-side electrode and an n-side electrode are provided in each of the first photoelectric conversion cell and the second photoelectric conversion cell.
  • a 1st photoelectric conversion cell and a 2nd photoelectric conversion cell can also be connected in parallel, and can also be connected to a mutually independent path
  • the insulating layer may be a non-doped layer. In this case, an insulating layer can be easily provided between the first photoelectric conversion cell and the second photoelectric conversion cell.
  • At least one of the first photoelectric conversion cell and the second photoelectric conversion cell may be configured by joining a plurality of subcells. In this case, the freedom degree of the combination of a photoelectric conversion cell can be raised.
  • At least one of the first photoelectric conversion cell and the second photoelectric conversion cell may be made of a compound semiconductor.
  • one of the photoelectric conversion cells can be formed together with the insulating layer by a vapor deposition method or the like, and the manufacture becomes easy.
  • FIG. 1 is a plan view of the photovoltaic device according to the first embodiment
  • FIG. 2 is a diagram showing a part of the section taken along line II-II in FIG. Is shown.
  • the photovoltaic device 1 is an element that generates electricity by photoelectric conversion by receiving light such as sunlight.
  • the photovoltaic device 1 has a rectangular shape in plan view.
  • the photovoltaic element 1 is configured by stacking a first photoelectric conversion cell 11, a second photoelectric conversion cell 12, and a third photoelectric conversion cell 13.
  • a step is formed by the end of each photoelectric conversion cell 11, 12, 13.
  • the photoelectric conversion cell is a semiconductor layer that includes a pn junction and generates power by photoelectric conversion based on incident light.
  • a first insulating layer 15 is interposed between the first photoelectric conversion cell 11 and the second photoelectric conversion cell 12. Further, a second insulating layer 16 is interposed between the second photoelectric conversion cell 12 and the third photoelectric conversion cell 13.
  • the light incident direction is a direction from the upper direction to the lower direction in the drawing, and in the following description, in each layer, the light incident side surface is referred to as the front surface and the opposite surface is referred to as the rear surface.
  • the first photoelectric conversion cell 11 includes a p-type Ge layer provided on the back surface side, and an n-type Ge layer provided on the p-type Ge layer and pn-junctioned with the p-type Ge layer.
  • the thickness of the first photoelectric conversion cell 11 is, for example, about 100 ⁇ m to 200 ⁇ m.
  • the 1st photoelectric conversion cell 11 is laminated
  • the first electrode 21 is made of, for example, an AuGeNi alloy.
  • the surface of the first photoelectric conversion cell 11 includes a laminated surface 23 on which the first insulating layer 15 is laminated and an exposed surface 24 exposed in the light incident direction.
  • the exposed surface 24 is provided on both edges along two sides parallel to each other on the surface of the first photoelectric conversion cell 11.
  • a second electrode 25 is provided on the exposed surface 24.
  • the second electrode 25 is formed on the exposed surfaces 24 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 24.
  • the second electrode 25 is made of, for example, an AuGeNi alloy.
  • the second electrode 25 forms an n-side electrode of the first photoelectric conversion cell 11 by being provided on the exposed surface 24 of the first photoelectric conversion cell 11.
  • the 1st electrode 21 comprises the p side electrode of the 1st photoelectric conversion cell 11 by laminating
  • the second photoelectric conversion cell 12 is laminated on the surface of the first electrode layer 31 laminated on the surface of the first insulating layer 15. That is, the first electrode layer 31 is stacked between the second photoelectric conversion cell 12 and the first insulating layer 15. Therefore, the first insulating layer 15 and the first electrode layer 31 are interposed between the second photoelectric conversion cell 12 and the first photoelectric conversion cell 11.
  • the first electrode layer 31 is a semiconductor layer, and is composed of, for example, a p-type InGaAsP layer doped with Zn at a high concentration of about 10 19 to 10 20 cm ⁇ 3 . Since the first electrode layer 31 is doped at a high concentration, the incident light may be attenuated. For this reason, it is preferable that the thickness of the 1st electrode layer 31 is 0.1 micrometer or less. Thereby, attenuation of incident light by the first electrode layer 31 can be suppressed.
  • the surface of the first electrode layer 31 includes a stacked surface 33 on which the second photoelectric conversion cells 12 are stacked and an exposed surface 34 exposed in the light incident direction. As shown in FIG. 1, the exposed surface 34 is provided on both edges of the two sides along the exposed surface 24 on the surface of the first electrode layer 31. A third electrode 35 is provided on the exposed surface 34. The third electrode 35 is formed on the exposed surfaces 34 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 34. The third electrode 35 is made of, for example, an AuGeNi alloy.
  • the second photoelectric conversion cell 12 includes a p-type InGaAs layer provided on the surface of the first electrode layer 31, and an n-type InGaAs layer provided on the p-type InGaAs layer and pn-junctioned with the p-type InGaAs layer. . That is, the second photoelectric conversion cell 12 constitutes a photoelectric conversion cell made of a compound semiconductor using InGaAs.
  • the thickness of the second photoelectric conversion cell 12 is, for example, about 2 ⁇ m to 5 ⁇ m.
  • the surface of the second photoelectric conversion cell 12 includes a stacked surface 36 on which the second insulating layer 16 is stacked and an exposed surface 37 exposed in the light incident direction. As shown in FIG.
  • the exposed surface 37 is provided on both edges of the two sides along the exposed surface 34 on the surface of the second photoelectric conversion cell 12.
  • a fourth electrode 38 is provided on the exposed surface 37.
  • the fourth electrode 38 is formed on the exposed surfaces 37 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 37.
  • the fourth electrode 38 is made of, for example, an AuGeNi alloy.
  • the fourth electrode 38 forms an n-side electrode of the second photoelectric conversion cell 12 by being provided on the exposed surface 37 of the second photoelectric conversion cell 12.
  • the first electrode layer 31 constitutes a p-type semiconductor layer in a state where the second photoelectric conversion cell 12 is laminated on the surface thereof. Therefore, the first electrode layer 31 and the third electrode 35 constitute a p-side electrode of the second photoelectric conversion cell 12.
  • the 1st electrode layer 31 is provided between the 2nd photoelectric conversion cell 12 and the 1st insulating layer 15, the 1st photoelectric conversion cell 11 and the 2nd photoelectric conversion are provided. Even if the cell 12 is stacked via the first insulating layer 15, a p-side electrode can be provided for the second photoelectric conversion cell 12.
  • the third photoelectric conversion cell 13 is stacked on the surface of the second electrode layer 41 stacked on the surface of the second insulating layer 16. That is, the second electrode layer 41 is stacked between the third photoelectric conversion cell 13 and the second insulating layer 16. Therefore, the second insulating layer 16 and the second electrode layer 41 are interposed between the third photoelectric conversion cell 13 and the second photoelectric conversion cell 12.
  • the second electrode layer 41 is a semiconductor layer, and is composed of a p-type InGaAsP layer doped with Zn at a high concentration of about 10 19 to 10 20 cm ⁇ 3 , for example, like the first electrode layer 31. Yes. Similarly to the first electrode layer 31, the second electrode layer 41 is also doped at a high concentration, so that there is a possibility that incident light may be attenuated. For this reason, it is preferable that the thickness of the 2nd electrode layer 41 is 0.1 micrometer or less. Thereby, attenuation of incident light by the first electrode layer 31 can be suppressed.
  • the surface of the second electrode layer 41 includes a stacked surface 43 on which the third photoelectric conversion cells 13 are stacked and an exposed surface 44 exposed in the light incident direction. As shown in FIG. 1, the exposed surface 44 is provided on both edges of the two sides along the exposed surface 37 on the surface of the second electrode layer 41. A fifth electrode 45 is provided on the exposed surface 44. The fifth electrode 45 is formed on the exposed surfaces 44 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 44.
  • the fifth electrode 45 is made of, for example, an AuGeNi alloy.
  • the third photoelectric conversion cell 13 includes a p-type InGaP layer provided on the surface of the second electrode layer 41, and an n-type InGaP layer provided on the p-type InGaP layer and pn-junctioned with the p-type InGaP layer. . That is, the third photoelectric conversion cell 13 constitutes a photoelectric conversion cell made of a compound semiconductor using InGaP.
  • the thickness of the third photoelectric conversion cell 13 is, for example, about 2 ⁇ m to 5 ⁇ m.
  • a sixth electrode 46 is provided on the surface 47 of the third photoelectric conversion cell 13.
  • the sixth electrode 46 includes a plurality of linear electrode portions that extend in parallel to two sides along the exposed surfaces 44 on both sides and are arranged on the surface 47 at a predetermined interval.
  • the sixth electrode 46 is made of, for example, an AuGeNi alloy.
  • the sixth electrode 46 constitutes the n-side electrode of the third photoelectric conversion cell 13 by being provided on the surface 47 of the third photoelectric conversion cell 13.
  • the second electrode layer 41 constitutes a p-type semiconductor layer in a state where the third photoelectric conversion cell 13 is laminated on the surface thereof. Therefore, the second electrode layer 41 and the fifth electrode 45 constitute a p-side electrode of the third photoelectric conversion cell 13.
  • the 2nd electrode layer 41 is provided between the 3rd photoelectric conversion cell 13 and the 2nd insulating layer 16, the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion are provided. Even if the cell 13 is stacked via the second insulating layer 16, a p-side electrode can be provided for the third photoelectric conversion cell 13.
  • the first insulating layer 15 is a semiconductor layer and is composed of a non-doped (not including dopant) InGaAs layer.
  • non-doped means that the semiconductor layer was formed without intentionally adding a dopant.
  • the non-doped InGaAs layer has a thickness of 0.01 ⁇ m to 0.2 ⁇ m and a dopant concentration of about 10 14 cm ⁇ 3 .
  • the first insulating layer 15 insulates between the first photoelectric conversion cell 11 and the first electrode layer 31 of the second photoelectric conversion cell 12.
  • the second insulating layer 16 is a semiconductor layer and is composed of a non-doped (not including dopant) InGaP layer. Similarly to the first insulating layer 15, the non-doped InGaP layer has a thickness of 0.01 ⁇ m to 0.2 ⁇ m and a dopant concentration of about 10 14 cm ⁇ 3 . Thereby, the second insulating layer 16 insulates between the second photoelectric conversion cell 12 and the second electrode layer 41 of the third photoelectric conversion cell 13.
  • the first photoelectric conversion cell 11 and the second photoelectric conversion cell 12 are stacked via the first insulating layer 15. Further, the second photoelectric conversion cell 12 and the third photoelectric conversion cell 13 are stacked via the second insulating layer 16. Therefore, each of the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be used as an independent photovoltaic device.
  • each of the photoelectric conversion cells 11, 12, and 13 is provided with a p-side electrode and an n-side electrode. Therefore, the first photoelectric conversion cell 11 can output the current generated from the first electrode 21 and the second electrode 25. Further, the second photoelectric conversion cell 12 can output a current generated from the third electrode 35 and the fourth electrode 38. Further, the third photoelectric conversion cell 13 can output a current generated from the fifth electrode 45 and the sixth electrode 46.
  • the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be connected in parallel to each other.
  • inverters I1, I2, and I3 are prepared for the photoelectric conversion cells 11, 12, and 13, respectively, and the photoelectric conversion cells 11, 12, and 13 are connected to independent paths to supply current. Can be output.
  • each photoelectric conversion cell 11, 12, 13 can be used as an independent photovoltaic device, and a current is output in an optimal state for each photoelectric conversion cell 11, 12, 13. be able to. As a result, it is possible to suppress a decrease in power generation efficiency as a whole of the photovoltaic device 1.
  • the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion cell 13 consist of compound semiconductors, the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion cell 13 are insulated so that it may mention later. It can be formed together with the layers 15 and 16 by vapor phase epitaxy and is easy to manufacture.
  • the first insulating layer 15, the first electrode layer 31, the second insulating layer 16, and the second insulating layer 16 are provided between the photoelectric conversion cells 11, 12, and 13. Since it is interposed, attenuation of incident light can be considered. However, since the first insulating layer 15 and the second insulating layer 16 are non-doped, the light transmittance is higher than that of the semiconductor layer doped. For this reason, incident light is not greatly attenuated.
  • the first electrode layer 31 and the second insulating layer 16 can suppress the attenuation of incident light by setting the thickness to 0.1 ⁇ m or less. As described above, the photovoltaic device 1 according to this embodiment can suppress the attenuation of incident light due to the insulating layers 15 and 16 and the electrode layers 31 and 41 provided.
  • FIG. 3A is a diagram for explaining a method of manufacturing the photovoltaic device 1 and is a partial cross-sectional view of a Ge substrate used for the photovoltaic device 1.
  • the right side of the drawing shows the end of the Ge substrate.
  • a Ge substrate 52 having an AuGeNi alloy layer 51 laminated on the back surface is prepared.
  • the Ge substrate 52 is previously configured to include a p-type Ge layer on the back surface side and an n-type Ge layer on the front surface side.
  • Each semiconductor layer is sequentially laminated on the surface of the Ge substrate 52 by a metal organic chemical vapor deposition method using MOCVD (Metal Organic Chemical Deposition).
  • MOCVD Metal Organic Chemical Deposition
  • FIG. 3B is a partial cross-sectional view of the first stacked body in which each semiconductor layer is formed.
  • the right side of the drawing shows the end of the Ge substrate (first stacked body).
  • a non-doped InGaAs layer that is the first insulating layer 15
  • a p-type InGaAsP layer that is the first electrode layer 31
  • an InGaAs layer that is the second photoelectric conversion cell 12.
  • P-type InGaAs layer and n-type InGaAs layer a non-doped InGaP layer that is the second insulating layer 16, a p-type InGaAsP layer that is the second electrode layer 41, and an InGaP layer that is the third photoelectric conversion cell 13 (p Type InGaP layer and n-type InGaP layer) are sequentially laminated.
  • the first stacked body 55 in which the respective semiconductor layers are stacked is obtained.
  • etching is performed on each layer of the first stacked body 55 to form exposed surfaces 24, 34, 37, and 44 at end portions of the respective layers.
  • FIG. 3C is a partial cross-sectional view of the first stacked body 55 after etching.
  • the right side of the drawing shows the end of the first stacked body 55.
  • the exposed surface 24 is formed on the surface of the first photoelectric conversion cell 11
  • the exposed surface 34 is formed on the surface of the first electrode layer 31
  • the first The exposed surface 37 is formed on the surface of the two photoelectric conversion cells 12, and the exposed surface 44 is formed on the surface of the second electrode layer 41.
  • the first electrode layer 31 and the second electrode layer 41 are InGaAsP layers, they can function as an etching stop layer. That is, the etching rate can be adjusted by adjusting the ratio of P, and the first electrode layer 31 and the second electrode layer 41 that are InGaAsP layers can be used as the etching stop layer. Thereby, the 1st electrode layer 31 and the 2nd electrode layer 41 of this embodiment can be functioned as an etching stop layer while functioning as an electrode.
  • the photovoltaic element 1 of this embodiment can be manufactured.
  • the photovoltaic device 1 of this embodiment can also be manufactured by the following method. That is, the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be individually formed and manufactured by joining them.
  • FIG. 4A is a diagram for explaining another manufacturing method of the photovoltaic device 1, and is a partial cross-sectional view of a stacked body corresponding to each photoelectric conversion cell.
  • the second stacked body 57 corresponding to the first photoelectric conversion cell 11 includes an AuGeNi alloy layer 61 to be the first electrode 21 and a Ge substrate 62 to be the first photoelectric conversion cell 11. Yes.
  • the Ge substrate 62 includes a p-type Ge layer and an n-type Ge layer.
  • the third stacked body 58 corresponding to the second photoelectric conversion cell 12 includes a non-doped InGaAs layer 71 to be the first insulating layer 15, a p-type InGaAsP layer 72 to be the first electrode layer 31, the second photoelectric conversion cell 12, and The InGaAs layer 73 is formed.
  • the InGaAs layer 73 includes a p-type InGaAs layer and an n-type InGaAs layer.
  • the fourth stacked body 59 corresponding to the third photoelectric conversion cell 13 includes a non-doped InGaP layer 81 serving as the second insulating layer 16, a p-type InGaAsP layer 82 serving as the second electrode layer 41, and the third photoelectric conversion cell 13.
  • the InGaP layer 83 is formed.
  • the InGaP layer 83 includes a p-type InGaP layer and an n-type InGaP layer.
  • the laminated bodies 58 and 59 can be formed by sequentially laminating each semiconductor layer by a metal organic chemical vapor deposition method or the like, similar to the method described above.
  • annealing is performed in a state where these stacked bodies 57, 58, and 59 are stacked, thereby bonding the stacked bodies 57, 58, and 59 to each other.
  • a first stacked body 55 in which the respective semiconductor layers are stacked is obtained.
  • the photovoltaic element 1 can be obtained by the same method as the manufacturing method shown in FIG. 3C.
  • the photovoltaic device 1 of the present embodiment is also manufactured by individually forming the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13, and joining them. can do.
  • FIG. 5 is a plan view of the end portion of the photovoltaic device according to the second embodiment
  • FIG. 6 is a view showing a part of the cross section taken along line VI-VI in FIG. The cross section is shown.
  • the first photoelectric conversion cell 111 and the second photoelectric conversion cell 112 that are two photoelectric conversion cells are stacked, and the first photoelectric conversion cell 111 is the first photoelectric conversion cell.
  • the second embodiment is different from the first embodiment in that the subcell 122 and the second subcell 129 are configured.
  • an insulating layer 115 is interposed between the first photoelectric conversion cell 111 and the second photoelectric conversion cell 112. Similar to the first embodiment, this photovoltaic element 1 is also rectangular in plan view, and at its end, a step is formed by the ends of the photoelectric conversion cells 111 and 112 as shown in FIG. ing.
  • the first photoelectric conversion cell 111 includes a first subcell 122 provided on the back surface side, a second subcell 129 stacked on the first subcell 122, and a tunnel junction layer 128 that joins both the subcells 122 and 129. .
  • the 1st photoelectric conversion cell 111 is laminated
  • the first electrode 121 is made of, for example, an AuGeNi alloy.
  • the first subcell 122 includes a p-type Ge layer provided on the back surface side, and an n-type Ge layer provided on the p-type Ge layer and pn-junctioned with the p-type Ge layer.
  • the second subcell 129 includes a p-type InGaAs layer provided on the back surface side, and an n-type InGaAs layer provided on the p-type InGaAs layer and pn-junctioned with the p-type InGaAs layer.
  • the tunnel junction layer 128 is interposed and joined between the first subcell 122 and the second subcell 129.
  • Tunnel junction layer 128 includes an n-type InGaAs layer provided on the first subcell 122 side and a p-type InGaAs layer provided on the second subcell 129 side.
  • the surface of the first photoelectric conversion cell 111 includes a laminated surface 123 on which the insulating layer 115 is laminated and an exposed surface 124 exposed in the light incident direction. As shown in FIG. 5, the exposed surface 124 is provided on both edges along two sides parallel to each other on the surface of the first photoelectric conversion cell 111.
  • a second electrode 125 is provided on the exposed surface 124.
  • the second electrode 125 is formed on the exposed surfaces 124 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 124.
  • the second electrode 125 is made of, for example, an AuGeNi alloy.
  • the second electrode 125 constitutes an n-side electrode of the first photoelectric conversion cell 111 by being provided on the exposed surface 124 of the first photoelectric conversion cell 111.
  • the 1st electrode 121 comprises the p side electrode of the 1st photoelectric conversion cell 111 by laminating
  • the second photoelectric conversion cell 112 is laminated on the surface of the first electrode layer 131 laminated on the surface of the insulating layer 115. That is, the second photoelectric conversion cell 112 and the first photoelectric conversion cell 111 are stacked with the insulating layer 115 and the first electrode layer 131 interposed therebetween.
  • the first electrode layer 131 is composed of a p-type InGaAsP layer doped at a high concentration.
  • the first electrode layer 131 has the same configuration as the first electrode layer 31 of the first embodiment.
  • the surface of the first electrode layer 131 includes a stacked surface 133 on which the second photoelectric conversion cells 112 are stacked, and an exposed surface 134 exposed in the light incident direction. As shown in FIG. 5, the exposed surface 134 is provided on both edges of the two sides along the exposed surface 124 on the surface of the first electrode layer 131.
  • a third electrode 135 is provided on the exposed surface 134.
  • the third electrode 135 is formed on the exposed surfaces 134 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 134.
  • the third electrode 135 is made of, for example, an AuGeNi alloy.
  • the second photoelectric conversion cell 112 includes a p-type InGaP layer provided on the surface of the first electrode layer 131, and an n-type InGaP layer provided on the p-type InGaP layer and pn-junctioned with the p-type InGaP layer. .
  • a fourth electrode 138 is provided on the surface 139 of the second photoelectric conversion cell 112.
  • the fourth electrode 138 includes a plurality of linear electrode portions that extend parallel to two sides along the exposed surfaces 134 on both sides and are arranged on the surface 139 at a predetermined interval.
  • the fourth electrode 138 is made of, for example, an AuGeNi alloy.
  • the fourth electrode 138 forms the n-side electrode of the second photoelectric conversion cell 112 by being provided on the surface 139 of the second photoelectric conversion cell 112.
  • the first electrode layer 131 forms a p-type semiconductor layer with the second photoelectric conversion cell 112 stacked on the surface thereof. Therefore, the first electrode layer 131 and the third electrode 135 constitute a p-side electrode of the second photoelectric conversion cell 112.
  • the insulating layer 115 is composed of a non-doped InGaP layer. Thereby, the first insulating layer 15 insulates between the first photoelectric conversion cell 11 and the first electrode layer 31 of the second photoelectric conversion cell 12.
  • the insulating layer 115 has the same configuration as the first insulating layer 15 and the second insulating layer 16 of the first embodiment.
  • the 1st photoelectric conversion cell 111 and the 2nd photoelectric conversion cell 112 are laminated
  • the 1st photoelectric conversion cell 11 was comprised by the 1st subcell 122 and the 2nd subcell 129, the freedom degree of the combination of a photoelectric conversion cell can be raised.
  • the manufacturing method of this embodiment can be manufactured by the same method as the manufacturing method of 1st Embodiment.
  • the embodiment disclosed this time should be considered as illustrative in all points and not restrictive.
  • the photovoltaic device 1 may be configured by two photoelectric conversion cells, or photovoltaic power generation using four or more photoelectric conversion cells.
  • the element 1 may be configured.
  • the insulating layers 15, 16, and 115 are configured by non-doped semiconductor layers (InGaAs layers or InGaP layers).
  • the composition of the insulating layer can be appropriately set according to the composition of the adjacent semiconductor layer.
  • the second insulating layer 16 is composed of a non-doped InGaP layer, but may be composed of an InGaAs layer having the same composition as that of the second photoelectric conversion cell 12 adjacent to the second insulating layer 16. .
  • the insulating layer only needs to be able to insulate the photoelectric conversion cells on both sides, for example, Fe
  • the insulating layer can also be constituted by a doped semiconductor layer.
  • the photoelectric conversion cell In each of the above embodiments, the case where a Ge cell using a Ge layer, an InGaAs cell using an InGaAs layer, or an InGaP cell using an InGaP layer is used as the photoelectric conversion cell.
  • the present invention is not limited to this.
  • a photoelectric conversion cell made of a semiconductor material can also be used.
  • the electrode layers 31, 41 and 131 are exemplified by the semiconductor layer (InGaAsP layer) doped at a high concentration.
  • the electrode layer is formed of a metal such as an AuGeNi alloy. Also good.
  • Photoelectric power generation element 11 1st photoelectric conversion cell 12 2nd photoelectric conversion cell 13 3rd photoelectric conversion cell 15 1st insulating layer 16 2nd insulating layer 21 1st electrode 23 Laminated surface 24 Exposed surface 25 2nd electrode 31 1st electrode Layer 33 Laminated surface 34 Exposed surface 35 Third electrode 36 Laminated surface 37 Exposed surface 38 Fourth electrode 41 Second electrode layer 43 Laminated surface 44 Exposed surface 45 Fifth electrode 46 Sixth electrode 47 Surface 51 AuGeNi alloy layer 52 Ge substrate 55 First laminated body 57 Second laminated body 58 Third laminated body 59 Fourth laminated body 61 AuGeNi alloy layer 62 Ge substrate 111 First photoelectric conversion cell 112 Second photoelectric conversion cell 115 Insulating layer 121 First electrode 122 First subcell 123 Laminated surface 124 Exposed surface 125 Second electrode 128 Tunnel junction layer 129 Second subcell 131 First electrode layer 133 Laminated surface 13 Exposed surface 135 third electrode 138 fourth electrode 139 surface I1, I2, I

Abstract

The present invention is a photovoltaic generation element including at least a first photoelectric conversion cell and a second photoelectric conversion cell. The first photoelectric conversion cell and the second photoelectric conversion cell are layered one on the other with a first insulating layer therebetween, said first insulating layer insulating the first photoelectric conversion cell and the second photoelectric conversion cell.

Description

光発電素子Photovoltaic element
　本発明は、光発電素子に関する。
　本出願は、２０１７年６月８日出願の日本出願第２０１７－１１３１００号に基づく優先権を主張し、前記日本出願に記載された全ての記載内容を援用するものである。 The present invention relates to a photovoltaic device.
This application claims priority based on Japanese Patent Application No. 2017-113100 filed on June 8, 2017, and incorporates all the description content described in the above Japanese application.
　近年、太陽光発電装置用の光発電素子として、複数の光電変換セルを積層してなる多接合型太陽電池素子が用いられることがある。
　この多接合型太陽電池素子は、複数の光電変換セルそれぞれのバンドギャップを異ならせることで、太陽光を幅広い波長域で吸収可能とし、高い発電効率が実現されている。
　例えば、特許文献１には、Ｇｅセル、ＧａＡｓセル、及びＡｌＩｎＧａＰセルをトンネル接合層で接合した３接合型の太陽電池素子が開示されている。 In recent years, a multi-junction solar cell element in which a plurality of photoelectric conversion cells are stacked may be used as a photovoltaic element for a photovoltaic power generation apparatus.
This multi-junction solar cell element can absorb sunlight in a wide wavelength range by making the band gaps of the plurality of photoelectric conversion cells different, and high power generation efficiency is realized.
For example, Patent Document 1 discloses a three-junction solar cell element in which a Ge cell, a GaAs cell, and an AlInGaP cell are joined by a tunnel junction layer.
特開２００５－１３６３３３号公報JP 2005-136333 A
　一実施形態である光発電素子は、少なくとも、第１光電変換セルと、第２光電変換セルと、を含む光発電素子であって、前記第１光電変換セルと、前記第２光電変換セルとは、前記第１光電変換セルと前記第２光電変換セルとを絶縁する絶縁層を介して積層されている。 The photovoltaic device which is one embodiment is a photovoltaic device including at least a first photoelectric conversion cell and a second photoelectric conversion cell, wherein the first photoelectric conversion cell, the second photoelectric conversion cell, Are stacked via an insulating layer that insulates the first photoelectric conversion cell from the second photoelectric conversion cell.
図１は、第１実施形態に係る光発電素子の平面図である。FIG. 1 is a plan view of the photovoltaic device according to the first embodiment. 図２は、図１中、ＩＩ－ＩＩ線矢視断面の一部を示す図である。FIG. 2 is a diagram showing a part of a cross section taken along line II-II in FIG. 図３Ａは、光発電素子の製造方法を説明するための図であって、光発電素子１に用いるＧｅ基板の一部断面図、図３Ｂは、各半導体層が形成された第１積層体の一部断面図、図３Ｃは、エッチング後の第１積層体の一部断面図である。FIG. 3A is a diagram for explaining a method for manufacturing a photovoltaic device, and is a partial cross-sectional view of a Ge substrate used for the photovoltaic device 1, and FIG. 3B is a diagram of a first stacked body in which each semiconductor layer is formed. FIG. 3C is a partial cross-sectional view of the first stacked body after etching. 図４Ａは、光発電素子の他の製造方法を説明するための図であって、各光電変換セルに対応する積層体の一部断面図、図４Ｂは、各積層体を接合して得られた第１積層体の一部断面図である。FIG. 4A is a diagram for explaining another method for manufacturing a photovoltaic device, and is a partial cross-sectional view of a laminated body corresponding to each photoelectric conversion cell, and FIG. 4B is obtained by joining the laminated bodies. It is a partial sectional view of the 1st layered product. 図５は、第２実施形態に係る光発電素子の平面図である。FIG. 5 is a plan view of the photovoltaic device according to the second embodiment. 図６は、図５中、ＶＩ－ＶＩ線矢視断面の一部を示す図である。FIG. 6 is a diagram showing a part of a cross section taken along line VI-VI in FIG.
［本開示が解決しようとする課題］
　上記多接合型の太陽電池素子では、各セルをトンネル接合層で接合して積層し、太陽電池素子の表面に設けられた表面電極と、太陽電池素子の裏面に設けられた裏面電極とから電力を出力するように構成されており、各セルは直列に接続されている。
　よって、多接合型の太陽電池素子により出力される電流値は、各セルにより出力される電流値の内、最も小さい電流値に制限されてしまう。
　このため、多接合型の太陽電池素子は、各セルにより出力される電流にできるだけ差が生じないように設計される。 [Problems to be solved by the present disclosure]
In the multi-junction type solar cell element, each cell is bonded and laminated by a tunnel junction layer, and power is supplied from a surface electrode provided on the surface of the solar cell element and a back electrode provided on the back surface of the solar cell element. Are output, and each cell is connected in series.
Therefore, the current value output by the multi-junction solar cell element is limited to the smallest current value among the current values output by each cell.
For this reason, the multi-junction solar cell element is designed so that there is as little difference as possible in the current output by each cell.
　ここで、太陽電池素子に到達する太陽光は、時間や季節による太陽高度の変化や、大気の状態、エアロゾルの存在等、周囲環境の変化によって増減する。このため、各セルが出力する電流は、周囲環境の変化によって変動する。
　このとき、太陽光に含まれる成分のうちの短波長域の成分は、周囲環境の変化の影響を大きく受けるため、太陽電池素子に到達するまでの間に、他の波長域の成分よりも相対的に大きく減少することがある。 Here, the sunlight that reaches the solar cell element increases or decreases due to changes in the surrounding environment such as changes in solar altitude due to time and season, atmospheric conditions, and the presence of aerosols. For this reason, the current output from each cell varies depending on changes in the surrounding environment.
At this time, the components in the short wavelength region among the components contained in the sunlight are greatly affected by changes in the surrounding environment, and therefore, relative to the components in other wavelength regions before reaching the solar cell element. May decrease significantly.
　このため、各セルの内、主として短波長域の成分を吸収するセルにおいては、周囲環境の変化による電流値の減少量が、他のセルの電流値の減少量よりも相対的に大きくなる。
　よって、各セルにより出力される電流の間で差が大きくなり、多接合型太陽電池素子全体としての発電効率が低下してしまうことがある。 For this reason, in each cell that mainly absorbs components in the short wavelength region, the amount of decrease in current value due to changes in the surrounding environment is relatively greater than the amount of decrease in current value of other cells.
Therefore, the difference between the currents output by each cell increases, and the power generation efficiency of the entire multi-junction solar cell element may decrease.
　このように、従来の多接合型の光発電素子では、各セルが直列に接続されることで、光発電素子全体の電流値が、各セルにより出力される電流値の内、最も小さい電流値に制限されるため、環境変化の影響等によって発電効率が低下することがあった。 As described above, in the conventional multi-junction photovoltaic device, each cell is connected in series, so that the current value of the entire photovoltaic device is the smallest current value among the current values output by each cell. Therefore, power generation efficiency may be reduced due to environmental changes.
　本開示はこのような事情に鑑みてなされたものであり、発電効率の低下を抑制することができる光発電素子の提供を目的とする。 The present disclosure has been made in view of such circumstances, and an object thereof is to provide a photovoltaic device capable of suppressing a decrease in power generation efficiency.
［本開示の効果］
　本開示によれば、発電効率の低下を抑制することができる。 [Effects of the present disclosure]
According to the present disclosure, it is possible to suppress a decrease in power generation efficiency.
［実施形態の説明］
　最初に実施形態の内容を列記して説明する。
（１）一実施形態である光発電素子は、少なくとも、第１光電変換セルと、第２光電変換セルと、を含む光発電素子であって、前記第１光電変換セルと、前記第２光電変換セルとは、前記第１光電変換セルと前記第２光電変換セルとを絶縁する絶縁層を介して積層されている。 [Description of Embodiment]
First, the contents of the embodiment will be listed and described.
(1) A photovoltaic device according to an embodiment is a photovoltaic device including at least a first photoelectric conversion cell and a second photoelectric conversion cell, wherein the first photoelectric conversion cell and the second photoelectric conversion cell are included. The conversion cell is laminated through an insulating layer that insulates the first photoelectric conversion cell and the second photoelectric conversion cell.
　上記構成の光発電素子によれば、絶縁層を介して第１光電変換セルと第２光電変換セルとが積層されているので、第１光電変換セル及び第２光電変換セルを独立した光発電素子として用いることができる。
　この結果、第１光電変換セルと第２光電変換セルとを並列に接続することもできるし、それぞれ独立した経路に接続することもできる。これにより、各セルそれぞれについて最適な状態で電流を出力させることができる。この結果、光発電素子全体として発電効率の低下を抑制することができる。 According to the photovoltaic device having the above configuration, since the first photoelectric conversion cell and the second photoelectric conversion cell are stacked via the insulating layer, the first photoelectric conversion cell and the second photoelectric conversion cell are independently photovoltaic. It can be used as an element.
As a result, the first photoelectric conversion cell and the second photoelectric conversion cell can be connected in parallel, or can be connected to independent paths. Thereby, it is possible to output current in an optimal state for each cell. As a result, it is possible to suppress a decrease in power generation efficiency as a whole photovoltaic power generation element.
（２）上記光発電素子において、前記第１光電変換セル及び前記第２光電変換セルのそれぞれに、ｐ側電極及びｎ側電極が設けられていることが好ましい。
　この場合、第１光電変換セルと第２光電変換セルとを並列に接続することもできるし、互いに独立した経路に接続することもできる。 (2) In the photovoltaic device, it is preferable that a p-side electrode and an n-side electrode are provided in each of the first photoelectric conversion cell and the second photoelectric conversion cell.
In this case, a 1st photoelectric conversion cell and a 2nd photoelectric conversion cell can also be connected in parallel, and can also be connected to a mutually independent path | route.
（３）上記光発電素子において、前記第１光電変換セル及び前記第２光電変換セルのうちのいずれか一方と、前記絶縁層との間には、前記ｐ側電極又は前記ｎ側電極のいずれか一方を構成する電極層が設けられていることが好ましい。
　これにより、第１光電変換セルと第２光電変換セルとを絶縁層を介して積層したとしても、一方の光電変換セルに対して電極を設けることができる。 (3) In the photovoltaic device, between the one of the first photoelectric conversion cell and the second photoelectric conversion cell and the insulating layer, either the p-side electrode or the n-side electrode It is preferable that an electrode layer constituting either of them is provided.
Thereby, even if a 1st photoelectric conversion cell and a 2nd photoelectric conversion cell are laminated | stacked through an insulating layer, an electrode can be provided with respect to one photoelectric conversion cell.
（４）また、上記光発電素子において、前記絶縁層は、ノンドープ層であってもよい。
　この場合、第１光電変換セルと第２光電変換セルとの間に、容易に絶縁層を設けることができる。 (4) In the photovoltaic device, the insulating layer may be a non-doped layer.
In this case, an insulating layer can be easily provided between the first photoelectric conversion cell and the second photoelectric conversion cell.
（５）また、上記光発電素子において、前記第１光電変換セル及び前記第２光電変換セルの内、少なくともいずれか一方が複数のサブセルを接合して構成されていてもよい。
　この場合、光電変換セルの組み合わせの自由度を高めることができる。 (5) In the photovoltaic device, at least one of the first photoelectric conversion cell and the second photoelectric conversion cell may be configured by joining a plurality of subcells.
In this case, the freedom degree of the combination of a photoelectric conversion cell can be raised.
（６）また、上記光発電素子において、前記第１光電変換セル及び前記第２光電変換セルの内、少なくともいずれか一方が化合物半導体からなるものであってもよい。
　この場合、一方の光電変換セルを、絶縁層とともに気相成長法等で形成することができ、製造が容易となる。 (6) In the photovoltaic device, at least one of the first photoelectric conversion cell and the second photoelectric conversion cell may be made of a compound semiconductor.
In this case, one of the photoelectric conversion cells can be formed together with the insulating layer by a vapor deposition method or the like, and the manufacture becomes easy.
［実施形態の詳細］
　以下、好ましい実施形態について図面を参照しつつ説明する。
　なお、以下に記載する各実施形態の少なくとも一部を任意に組み合わせてもよい。 [Details of the embodiment]
Hereinafter, preferred embodiments will be described with reference to the drawings.
Note that at least a part of each embodiment described below may be arbitrarily combined.
〔第１実施形態について〕
　図１は、第１実施形態に係る光発電素子の平面図、図２は、図１中、ＩＩ－ＩＩ線矢視断面の一部を示す図であって、光発電素子１の端部断面を示している。
　光発電素子１は、太陽光等の光を受光することで光電変換による発電を行う素子である。光発電素子１は、図１に示すように、平面視において矩形状とされている。
　光発電素子１は、図２に示すように、第１光電変換セル１１と、第２光電変換セル１２と、第３光電変換セル１３とを積層して構成されている。光発電素子１の端部には、各光電変換セル１１，１２，１３の端部によって段差が形成されている。
　なお、ここで、光電変換セルとは、ｐｎ接合を含む半導体層であって入射光に基づく光電変換によって発電する半導体層である。 [About the first embodiment]
FIG. 1 is a plan view of the photovoltaic device according to the first embodiment, and FIG. 2 is a diagram showing a part of the section taken along line II-II in FIG. Is shown.
The photovoltaic device 1 is an element that generates electricity by photoelectric conversion by receiving light such as sunlight. As shown in FIG. 1, the photovoltaic device 1 has a rectangular shape in plan view.
As shown in FIG. 2, the photovoltaic element 1 is configured by stacking a first photoelectric conversion cell 11, a second photoelectric conversion cell 12, and a third photoelectric conversion cell 13. At the end of the photovoltaic device 1, a step is formed by the end of each photoelectric conversion cell 11, 12, 13.
Here, the photoelectric conversion cell is a semiconductor layer that includes a pn junction and generates power by photoelectric conversion based on incident light.
　第１光電変換セル１１と、第２光電変換セル１２との間には、第１絶縁層１５が介在している。
　また、第２光電変換セル１２と、第３光電変換セル１３との間には、第２絶縁層１６が介在している。
　なお、図２において、光の入射方向は、紙面上方向から下方向に向く方向であり、以下の説明では、各層において、光の入射側面を表面、その反対面を裏面という。 A first insulating layer 15 is interposed between the first photoelectric conversion cell 11 and the second photoelectric conversion cell 12.
Further, a second insulating layer 16 is interposed between the second photoelectric conversion cell 12 and the third photoelectric conversion cell 13.
In FIG. 2, the light incident direction is a direction from the upper direction to the lower direction in the drawing, and in the following description, in each layer, the light incident side surface is referred to as the front surface and the opposite surface is referred to as the rear surface.
　第１光電変換セル１１は、裏面側に設けられたｐ型Ｇｅ層と、ｐ型Ｇｅ層上に設けられｐ型Ｇｅ層とｐｎ接合されたｎ型Ｇｅ層とを含む。
　第１光電変換セル１１の厚さは、例えば、１００μｍ～２００μｍ程度である。
　第１光電変換セル１１は、層状に形成された第１電極２１の表面に積層されている。第１電極２１は、例えば、ＡｕＧｅＮｉ合金よりなる。
　第１光電変換セル１１の表面は、第１絶縁層１５が積層されている積層面２３と、光の入射方向に露出している露出面２４とを含む。 The first photoelectric conversion cell 11 includes a p-type Ge layer provided on the back surface side, and an n-type Ge layer provided on the p-type Ge layer and pn-junctioned with the p-type Ge layer.
The thickness of the first photoelectric conversion cell 11 is, for example, about 100 μm to 200 μm.
The 1st photoelectric conversion cell 11 is laminated | stacked on the surface of the 1st electrode 21 formed in the layer form. The first electrode 21 is made of, for example, an AuGeNi alloy.
The surface of the first photoelectric conversion cell 11 includes a laminated surface 23 on which the first insulating layer 15 is laminated and an exposed surface 24 exposed in the light incident direction.
　露出面２４は、図１に示すように、第１光電変換セル１１の表面において互いに平行な２辺に沿う縁部両方に設けられている。
　露出面２４には、第２電極２５が設けられている。第２電極２５は、両側の露出面２４に形成されており、露出面２４の長手方向に沿って線状に形成されている。第２電極２５は、例えば、ＡｕＧｅＮｉ合金よりなる。
　第２電極２５は、第１光電変換セル１１の露出面２４に設けられることで第１光電変換セル１１のｎ側電極を構成している。
　また、第１電極２１は、その表面上に第１光電変換セル１１が積層されることで第１光電変換セル１１のｐ側電極を構成している。 As shown in FIG. 1, the exposed surface 24 is provided on both edges along two sides parallel to each other on the surface of the first photoelectric conversion cell 11.
A second electrode 25 is provided on the exposed surface 24. The second electrode 25 is formed on the exposed surfaces 24 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 24. The second electrode 25 is made of, for example, an AuGeNi alloy.
The second electrode 25 forms an n-side electrode of the first photoelectric conversion cell 11 by being provided on the exposed surface 24 of the first photoelectric conversion cell 11.
Moreover, the 1st electrode 21 comprises the p side electrode of the 1st photoelectric conversion cell 11 by laminating | stacking the 1st photoelectric conversion cell 11 on the surface.
　第２光電変換セル１２は、第１絶縁層１５の表面に積層された第１電極層３１の表面に積層されている。つまり、第２光電変換セル１２と、第１絶縁層１５との間には、第１電極層３１が積層されている。よって、第２光電変換セル１２と、第１光電変換セル１１との間には、第１絶縁層１５と、第１電極層３１とが介在している。 The second photoelectric conversion cell 12 is laminated on the surface of the first electrode layer 31 laminated on the surface of the first insulating layer 15. That is, the first electrode layer 31 is stacked between the second photoelectric conversion cell 12 and the first insulating layer 15. Therefore, the first insulating layer 15 and the first electrode layer 31 are interposed between the second photoelectric conversion cell 12 and the first photoelectric conversion cell 11.
　第１電極層３１は、半導体層であり、例えば、Ｚｎを１０１９～１０２０ｃｍ－３程度の高濃度でドーピングしたｐ型のＩｎＧａＡｓＰ層で構成されている。
　第１電極層３１は、高濃度でドーピングされているため、入射光を減衰させるおそれがある。このため、第１電極層３１の厚さは、０．１μｍ以下であることが好ましい。これにより、第１電極層３１による入射光の減衰を抑制することができる。 The first electrode layer 31 is a semiconductor layer, and is composed of, for example, a p-type InGaAsP layer doped with Zn at a high concentration of about 10 19 to 10 20 cm −3 .
Since the first electrode layer 31 is doped at a high concentration, the incident light may be attenuated. For this reason, it is preferable that the thickness of the 1st electrode layer 31 is 0.1 micrometer or less. Thereby, attenuation of incident light by the first electrode layer 31 can be suppressed.
　第１電極層３１の表面は、第２光電変換セル１２が積層されている積層面３３と、光の入射方向に露出している露出面３４とを含む。
　露出面３４は、図１に示すように、第１電極層３１の表面において露出面２４に沿う２辺の縁部両方に設けられている。
　露出面３４には、第３電極３５が設けられている。第３電極３５は、両側の露出面３４に形成されており、露出面３４の長手方向に沿って線状に形成されている。第３電極３５は、例えば、ＡｕＧｅＮｉ合金よりなる。 The surface of the first electrode layer 31 includes a stacked surface 33 on which the second photoelectric conversion cells 12 are stacked and an exposed surface 34 exposed in the light incident direction.
As shown in FIG. 1, the exposed surface 34 is provided on both edges of the two sides along the exposed surface 24 on the surface of the first electrode layer 31.
A third electrode 35 is provided on the exposed surface 34. The third electrode 35 is formed on the exposed surfaces 34 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 34. The third electrode 35 is made of, for example, an AuGeNi alloy.
　第２光電変換セル１２は、第１電極層３１の表面上に設けられたｐ型ＩｎＧａＡｓ層と、ｐ型ＩｎＧａＡｓ層上に設けられｐ型ＩｎＧａＡｓ層とｐｎ接合されたｎ型ＩｎＧａＡｓ層とを含む。つまり、第２光電変換セル１２は、ＩｎＧａＡｓを用いた化合物半導体からなる光電変換セルを構成する。
　第２光電変換セル１２の厚さは、例えば、２μｍ～５μｍ程度である。
　第２光電変換セル１２の表面は、第２絶縁層１６が積層されている積層面３６と、光の入射方向に露出している露出面３７とを含む。
　露出面３７は、図１に示すように、第２光電変換セル１２の表面において露出面３４に沿う２辺の縁部両方に設けられている。
　露出面３７には、第４電極３８が設けられている。第４電極３８は、両側の露出面３７に形成されており、露出面３７の長手方向に沿って線状に形成されている。第４電極３８は、例えば、ＡｕＧｅＮｉ合金よりなる。 The second photoelectric conversion cell 12 includes a p-type InGaAs layer provided on the surface of the first electrode layer 31, and an n-type InGaAs layer provided on the p-type InGaAs layer and pn-junctioned with the p-type InGaAs layer. . That is, the second photoelectric conversion cell 12 constitutes a photoelectric conversion cell made of a compound semiconductor using InGaAs.
The thickness of the second photoelectric conversion cell 12 is, for example, about 2 μm to 5 μm.
The surface of the second photoelectric conversion cell 12 includes a stacked surface 36 on which the second insulating layer 16 is stacked and an exposed surface 37 exposed in the light incident direction.
As shown in FIG. 1, the exposed surface 37 is provided on both edges of the two sides along the exposed surface 34 on the surface of the second photoelectric conversion cell 12.
A fourth electrode 38 is provided on the exposed surface 37. The fourth electrode 38 is formed on the exposed surfaces 37 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 37. The fourth electrode 38 is made of, for example, an AuGeNi alloy.
　第４電極３８は、第２光電変換セル１２の露出面３７に設けられることで第２光電変換セル１２のｎ側電極を構成している。
　また、第１電極層３１は、その表面上に第２光電変換セル１２が積層された状態でｐ型の半導体層を構成している。よって、第１電極層３１及び第３電極３５は、第２光電変換セル１２のｐ側電極を構成している。 The fourth electrode 38 forms an n-side electrode of the second photoelectric conversion cell 12 by being provided on the exposed surface 37 of the second photoelectric conversion cell 12.
The first electrode layer 31 constitutes a p-type semiconductor layer in a state where the second photoelectric conversion cell 12 is laminated on the surface thereof. Therefore, the first electrode layer 31 and the third electrode 35 constitute a p-side electrode of the second photoelectric conversion cell 12.
　このように、本実施形態では、第２光電変換セル１２と、第１絶縁層１５との間に、第１電極層３１が設けられているので、第１光電変換セル１１と第２光電変換セル１２とを第１絶縁層１５を介して積層したとしても、第２光電変換セル１２に対してｐ側電極を設けることができる。 Thus, in this embodiment, since the 1st electrode layer 31 is provided between the 2nd photoelectric conversion cell 12 and the 1st insulating layer 15, the 1st photoelectric conversion cell 11 and the 2nd photoelectric conversion are provided. Even if the cell 12 is stacked via the first insulating layer 15, a p-side electrode can be provided for the second photoelectric conversion cell 12.
　第３光電変換セル１３は、第２絶縁層１６の表面に積層された第２電極層４１の表面に積層されている。つまり、第３光電変換セル１３と、第２絶縁層１６との間には、第２電極層４１が積層されている。よって、第３光電変換セル１３と、第２光電変換セル１２との間には、第２絶縁層１６と、第２電極層４１とが介在している。 The third photoelectric conversion cell 13 is stacked on the surface of the second electrode layer 41 stacked on the surface of the second insulating layer 16. That is, the second electrode layer 41 is stacked between the third photoelectric conversion cell 13 and the second insulating layer 16. Therefore, the second insulating layer 16 and the second electrode layer 41 are interposed between the third photoelectric conversion cell 13 and the second photoelectric conversion cell 12.
　第２電極層４１は、半導体層であり、第１電極層３１と同様に、例えば、Ｚｎを１０１９～１０２０ｃｍ－３程度の高濃度でドーピングされたｐ型のＩｎＧａＡｓＰ層で構成されている。
　第２電極層４１も、第１電極層３１と同様、高濃度でドーピングされているため、入射光を減衰させるおそれがある。このため、第２電極層４１の厚さは、０．１μｍ以下であることが好ましい。これにより、第１電極層３１による入射光の減衰を抑制することができる。 The second electrode layer 41 is a semiconductor layer, and is composed of a p-type InGaAsP layer doped with Zn at a high concentration of about 10 19 to 10 20 cm −3 , for example, like the first electrode layer 31. Yes.
Similarly to the first electrode layer 31, the second electrode layer 41 is also doped at a high concentration, so that there is a possibility that incident light may be attenuated. For this reason, it is preferable that the thickness of the 2nd electrode layer 41 is 0.1 micrometer or less. Thereby, attenuation of incident light by the first electrode layer 31 can be suppressed.
　第２電極層４１の表面は、第３光電変換セル１３が積層されている積層面４３と、光の入射方向に露出している露出面４４とを含む。
　露出面４４は、図１に示すように、第２電極層４１の表面において露出面３７に沿う２辺の縁部両方に設けられている。
　露出面４４には、第５電極４５が設けられている。第５電極４５は、両側の露出面４４に形成されており、露出面４４の長手方向に沿って線状に形成されている。第５電極４５は、例えば、ＡｕＧｅＮｉ合金よりなる。 The surface of the second electrode layer 41 includes a stacked surface 43 on which the third photoelectric conversion cells 13 are stacked and an exposed surface 44 exposed in the light incident direction.
As shown in FIG. 1, the exposed surface 44 is provided on both edges of the two sides along the exposed surface 37 on the surface of the second electrode layer 41.
A fifth electrode 45 is provided on the exposed surface 44. The fifth electrode 45 is formed on the exposed surfaces 44 on both sides, and is formed linearly along the longitudinal direction of the exposed surface 44. The fifth electrode 45 is made of, for example, an AuGeNi alloy.
　第３光電変換セル１３は、第２電極層４１の表面上に設けられたｐ型ＩｎＧａＰ層と、ｐ型ＩｎＧａＰ層上に設けられｐ型ＩｎＧａＰ層とｐｎ接合されたｎ型ＩｎＧａＰ層とを含む。つまり、第３光電変換セル１３は、ＩｎＧａＰを用いた化合物半導体からなる光電変換セルを構成する。
　第３光電変換セル１３の厚さは、例えば、２μｍ～５μｍ程度である。
　第３光電変換セル１３の表面４７には、第６電極４６が設けられている。第６電極４６は、両側の露出面４４に沿う２辺に対して平行に延びているとともに表面４７に所定間隔で並べられている線状の電極部を複数備えている。第６電極４６は、例えば、ＡｕＧｅＮｉ合金よりなる。 The third photoelectric conversion cell 13 includes a p-type InGaP layer provided on the surface of the second electrode layer 41, and an n-type InGaP layer provided on the p-type InGaP layer and pn-junctioned with the p-type InGaP layer. . That is, the third photoelectric conversion cell 13 constitutes a photoelectric conversion cell made of a compound semiconductor using InGaP.
The thickness of the third photoelectric conversion cell 13 is, for example, about 2 μm to 5 μm.
A sixth electrode 46 is provided on the surface 47 of the third photoelectric conversion cell 13. The sixth electrode 46 includes a plurality of linear electrode portions that extend in parallel to two sides along the exposed surfaces 44 on both sides and are arranged on the surface 47 at a predetermined interval. The sixth electrode 46 is made of, for example, an AuGeNi alloy.
　第６電極４６は、第３光電変換セル１３の表面４７に設けられることで第３光電変換セル１３のｎ側電極を構成している。
　また、第２電極層４１は、その表面上に第３光電変換セル１３が積層された状態でｐ型の半導体層を構成している。よって、第２電極層４１及び第５電極４５は、第３光電変換セル１３のｐ側電極を構成している。 The sixth electrode 46 constitutes the n-side electrode of the third photoelectric conversion cell 13 by being provided on the surface 47 of the third photoelectric conversion cell 13.
The second electrode layer 41 constitutes a p-type semiconductor layer in a state where the third photoelectric conversion cell 13 is laminated on the surface thereof. Therefore, the second electrode layer 41 and the fifth electrode 45 constitute a p-side electrode of the third photoelectric conversion cell 13.
　このように、本実施形態では、第３光電変換セル１３と、第２絶縁層１６との間に、第２電極層４１が設けられているので、第２光電変換セル１２と第３光電変換セル１３とを第２絶縁層１６を介して積層したとしても、第３光電変換セル１３に対してｐ側電極を設けることができる。 Thus, in this embodiment, since the 2nd electrode layer 41 is provided between the 3rd photoelectric conversion cell 13 and the 2nd insulating layer 16, the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion are provided. Even if the cell 13 is stacked via the second insulating layer 16, a p-side electrode can be provided for the third photoelectric conversion cell 13.
　第１絶縁層１５は、半導体層であり、ノンドープ（ドーパントを含まない）のＩｎＧａＡｓ層で構成されている。なお、ノンドープとは、ドーパントを意図的に添加せずに半導体層を形成したことを意味する。ノンドープのＩｎＧａＡｓ層は、例えば、その厚さが０．０１μｍ～０．２μｍ、ドーパントの濃度が１０１４ｃｍ－３程度とされている。これにより、第１絶縁層１５は、第１光電変換セル１１と、第２光電変換セル１２の第１電極層３１との間を絶縁している。 The first insulating layer 15 is a semiconductor layer and is composed of a non-doped (not including dopant) InGaAs layer. Note that non-doped means that the semiconductor layer was formed without intentionally adding a dopant. For example, the non-doped InGaAs layer has a thickness of 0.01 μm to 0.2 μm and a dopant concentration of about 10 14 cm −3 . Thereby, the first insulating layer 15 insulates between the first photoelectric conversion cell 11 and the first electrode layer 31 of the second photoelectric conversion cell 12.
　第２絶縁層１６は、半導体層であり、ノンドープ（ドーパントを含まない）のＩｎＧａＰ層で構成されている。ノンドープのＩｎＧａＰ層も、第１絶縁層１５と同様、その厚さが０．０１μｍ～０．２μｍ、ドーパントの濃度が１０１４ｃｍ－３程度とされている。これにより、第２絶縁層１６は、第２光電変換セル１２と、第３光電変換セル１３の第２電極層４１との間を絶縁している。 The second insulating layer 16 is a semiconductor layer and is composed of a non-doped (not including dopant) InGaP layer. Similarly to the first insulating layer 15, the non-doped InGaP layer has a thickness of 0.01 μm to 0.2 μm and a dopant concentration of about 10 14 cm −3 . Thereby, the second insulating layer 16 insulates between the second photoelectric conversion cell 12 and the second electrode layer 41 of the third photoelectric conversion cell 13.
　本実施形態の光発電素子１では、第１絶縁層１５を介して第１光電変換セル１１と第２光電変換セル１２とが積層されている。また、第２絶縁層１６を介して第２光電変換セル１２と第３光電変換セル１３とが積層されている。よって、第１光電変換セル１１、第２光電変換セル１２、及び第３光電変換セル１３それぞれを独立した光発電素子として用いることができる。 In the photovoltaic device 1 of the present embodiment, the first photoelectric conversion cell 11 and the second photoelectric conversion cell 12 are stacked via the first insulating layer 15. Further, the second photoelectric conversion cell 12 and the third photoelectric conversion cell 13 are stacked via the second insulating layer 16. Therefore, each of the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be used as an independent photovoltaic device.
　さらに、光発電素子１は、各光電変換セル１１，１２，１３それぞれに、ｐ側電極及びｎ側電極が設けられている。
　よって、第１光電変換セル１１は、第１電極２１及び第２電極２５から発電した電流を出力することができる。また、第２光電変換セル１２は、第３電極３５及び第４電極３８から発電した電流を出力することができる。さらに、第３光電変換セル１３は、第５電極４５及び第６電極４６から発電した電流を出力することができる。 Furthermore, in the photovoltaic device 1, each of the photoelectric conversion cells 11, 12, and 13 is provided with a p-side electrode and an n-side electrode.
Therefore, the first photoelectric conversion cell 11 can output the current generated from the first electrode 21 and the second electrode 25. Further, the second photoelectric conversion cell 12 can output a current generated from the third electrode 35 and the fourth electrode 38. Further, the third photoelectric conversion cell 13 can output a current generated from the fifth electrode 45 and the sixth electrode 46.
　この結果、第１光電変換セル１１、第２光電変換セル１２、及び第３光電変換セル１３を互いに並列に接続することもできる。
　また、図２に示すように、各光電変換セル１１，１２，１３それぞれにインバータＩ１，Ｉ２，Ｉ３を用意し、各光電変換セル１１，１２，１３それぞれを独立した経路に接続して電流を出力させることができる。 As a result, the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be connected in parallel to each other.
In addition, as shown in FIG. 2, inverters I1, I2, and I3 are prepared for the photoelectric conversion cells 11, 12, and 13, respectively, and the photoelectric conversion cells 11, 12, and 13 are connected to independent paths to supply current. Can be output.
　このように、本実施形態では、各光電変換セル１１，１２，１３それぞれを独立した光発電素子として用いることができ、各光電変換セル１１，１２，１３それぞれについて最適な状態で電流を出力させることができる。この結果、光発電素子１全体として発電効率の低下を抑制することができる。 Thus, in this embodiment, each photoelectric conversion cell 11, 12, 13 can be used as an independent photovoltaic device, and a current is output in an optimal state for each photoelectric conversion cell 11, 12, 13. be able to. As a result, it is possible to suppress a decrease in power generation efficiency as a whole of the photovoltaic device 1.
　また、本実施形態では、第２光電変換セル１２、及び第３光電変換セル１３が化合物半導体からなるので、後述するように、第２光電変換セル１２、及び第３光電変換セル１３を、絶縁層１５，１６とともに気相成長法で形成することができ、製造が容易である。 Moreover, in this embodiment, since the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion cell 13 consist of compound semiconductors, the 2nd photoelectric conversion cell 12 and the 3rd photoelectric conversion cell 13 are insulated so that it may mention later. It can be formed together with the layers 15 and 16 by vapor phase epitaxy and is easy to manufacture.
　なお、本実施形態の光発電素子１は、各光電変換セル１１，１２，１３の間に、第１絶縁層１５、第１電極層３１、第２絶縁層１６、及び第２絶縁層１６を介在させたので、入射光の減衰が考えられる。
　しかし、第１絶縁層１５及び第２絶縁層１６は、ノンドープのため、光の透過率がドーピングされている半導体層と比較して高い。このため、入射光を大きく減衰させることがない。
　また、第１電極層３１、及び第２絶縁層１６は、厚さを０．１μｍ以下とすることで、入射光の減衰を抑制することができる。
　以上により、本実施形態の光発電素子１は、絶縁層１５，１６及び電極層３１，４１を設けたにもかかわらず、これらによる入射光の減衰を抑えることができる。 In the photovoltaic device 1 of the present embodiment, the first insulating layer 15, the first electrode layer 31, the second insulating layer 16, and the second insulating layer 16 are provided between the photoelectric conversion cells 11, 12, and 13. Since it is interposed, attenuation of incident light can be considered.
However, since the first insulating layer 15 and the second insulating layer 16 are non-doped, the light transmittance is higher than that of the semiconductor layer doped. For this reason, incident light is not greatly attenuated.
The first electrode layer 31 and the second insulating layer 16 can suppress the attenuation of incident light by setting the thickness to 0.1 μm or less.
As described above, the photovoltaic device 1 according to this embodiment can suppress the attenuation of incident light due to the insulating layers 15 and 16 and the electrode layers 31 and 41 provided.
　次に、本実施形態に係る光発電素子１の製造方法について説明する。
　図３Ａは、光発電素子１の製造方法を説明するための図であって、光発電素子１に用いるＧｅ基板の一部断面図である。なお、図３Ａ中、紙面右側がＧｅ基板の端部を示している。
　まず、図３Ａに示すように、裏面にＡｕＧｅＮｉ合金層５１が裏面に積層されたＧｅ基板５２を用意する。このＧｅ基板５２は、予め、裏面側にｐ型Ｇｅ層、表面側にｎ型Ｇｅ層を含むように構成される。 Next, a method for manufacturing the photovoltaic device 1 according to this embodiment will be described.
FIG. 3A is a diagram for explaining a method of manufacturing the photovoltaic device 1 and is a partial cross-sectional view of a Ge substrate used for the photovoltaic device 1. In FIG. 3A, the right side of the drawing shows the end of the Ge substrate.
First, as shown in FIG. 3A, a Ge substrate 52 having an AuGeNi alloy layer 51 laminated on the back surface is prepared. The Ge substrate 52 is previously configured to include a p-type Ge layer on the back surface side and an n-type Ge layer on the front surface side.
　このＧｅ基板５２の表面に、ＭＯＣＶＤ（Ｍｅｔａｌ　Ｏｒｇａｎｉｃ　Ｃｈｅｍｉｃａｌ　Ｖａｐｏｒ　Ｄｅｐｏｓｉｔｉｏｎ）を用いた有機金属化学気相法等によって、各半導体層を順次積層する。 Each semiconductor layer is sequentially laminated on the surface of the Ge substrate 52 by a metal organic chemical vapor deposition method using MOCVD (Metal Organic Chemical Deposition).
　図３Ｂは、各半導体層が形成された第１積層体の一部断面図である。なお、図３Ｂ中、紙面右側がＧｅ基板（第１積層体）の端部を示している。
　第１光電変換セル１１となるＧｅ基板５２上には、第１絶縁層１５であるノンドープのＩｎＧａＡｓ層、第１電極層３１であるｐ型のＩｎＧａＡｓＰ層、第２光電変換セル１２であるＩｎＧａＡｓ層（ｐ型ＩｎＧａＡｓ層及びｎ型ＩｎＧａＡｓ層）、第２絶縁層１６であるノンドープのＩｎＧａＰ層、第２電極層４１であるｐ型のＩｎＧａＡｓＰ層、及び第３光電変換セル１３であるＩｎＧａＰ層（ｐ型ＩｎＧａＰ層及びｎ型ＩｎＧａＰ層）が順次積層される。 FIG. 3B is a partial cross-sectional view of the first stacked body in which each semiconductor layer is formed. In FIG. 3B, the right side of the drawing shows the end of the Ge substrate (first stacked body).
On the Ge substrate 52 to be the first photoelectric conversion cell 11, a non-doped InGaAs layer that is the first insulating layer 15, a p-type InGaAsP layer that is the first electrode layer 31, and an InGaAs layer that is the second photoelectric conversion cell 12. (P-type InGaAs layer and n-type InGaAs layer), a non-doped InGaP layer that is the second insulating layer 16, a p-type InGaAsP layer that is the second electrode layer 41, and an InGaP layer that is the third photoelectric conversion cell 13 (p Type InGaP layer and n-type InGaP layer) are sequentially laminated.
　このように、Ｇｅ基板５２の表面に各半導体層を積層形成することで、各半導体層が積層された第１積層体５５が得られる。
　次いで、第１積層体５５の各層に対してエッチングを行い、各層の端部における露出面２４，３４，３７，４４を形成する。 In this manner, by forming each semiconductor layer on the surface of the Ge substrate 52, the first stacked body 55 in which the respective semiconductor layers are stacked is obtained.
Next, etching is performed on each layer of the first stacked body 55 to form exposed surfaces 24, 34, 37, and 44 at end portions of the respective layers.
　図３Ｃは、エッチング後の第１積層体５５の一部断面図である。なお、図３Ｃ中、紙面右側が第１積層体５５の端部を示している。
　図３Ｃに示すように、エッチング後の第１積層体５５には、第１光電変換セル１１の表面に露出面２４が形成され、第１電極層３１の表面に露出面３４が形成され、第２光電変換セル１２の表面に露出面３７が形成され、第２電極層４１の表面に露出面４４が形成されている。 FIG. 3C is a partial cross-sectional view of the first stacked body 55 after etching. In FIG. 3C, the right side of the drawing shows the end of the first stacked body 55.
As shown in FIG. 3C, in the etched first stacked body 55, the exposed surface 24 is formed on the surface of the first photoelectric conversion cell 11, the exposed surface 34 is formed on the surface of the first electrode layer 31, and the first The exposed surface 37 is formed on the surface of the two photoelectric conversion cells 12, and the exposed surface 44 is formed on the surface of the second electrode layer 41.
　なお、このとき、第１電極層３１及び第２電極層４１をＩｎＧａＡｓＰ層とすることで、エッチングストップ層として機能させることができる。すなわち、Ｐの比率を調整することでエッチングレートを調整し、ＩｎＧａＡｓＰ層である第１電極層３１及び第２電極層４１をエッチングストップ層とすることができる。
　これにより、本実施形態の第１電極層３１及び第２電極層４１は、電極として機能させるとともに、エッチングストップ層として機能させることができる。 At this time, if the first electrode layer 31 and the second electrode layer 41 are InGaAsP layers, they can function as an etching stop layer. That is, the etching rate can be adjusted by adjusting the ratio of P, and the first electrode layer 31 and the second electrode layer 41 that are InGaAsP layers can be used as the etching stop layer.
Thereby, the 1st electrode layer 31 and the 2nd electrode layer 41 of this embodiment can be functioned as an etching stop layer while functioning as an electrode.
　エッチングにより、各露出面２４，３４，３７，４４を形成した後、蒸着等によって、第２電極２５、第３電極３５、第４電極３８、第５電極４５、及び第６電極４６を形成する。
　以上により、本実施形態の光発電素子１を製造することができる。 After the exposed surfaces 24, 34, 37, 44 are formed by etching, the second electrode 25, the third electrode 35, the fourth electrode 38, the fifth electrode 45, and the sixth electrode 46 are formed by vapor deposition or the like. .
As described above, the photovoltaic element 1 of this embodiment can be manufactured.
　また、本実施形態の光発電素子１は、以下の方法によっても製造することができる。
　すなわち、第１光電変換セル１１、第２光電変換セル１２、及び第３光電変換セル１３を個別に形成し、これらを接合することによって製造することができる。 Moreover, the photovoltaic device 1 of this embodiment can also be manufactured by the following method.
That is, the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13 can be individually formed and manufactured by joining them.
　図４Ａは、光発電素子１の他の製造方法を説明するための図であって、各光電変換セルに対応する積層体の一部断面図である。 FIG. 4A is a diagram for explaining another manufacturing method of the photovoltaic device 1, and is a partial cross-sectional view of a stacked body corresponding to each photoelectric conversion cell.
　図４Ａ中、第１光電変換セル１１に対応する第２積層体５７は、第１電極２１となるＡｕＧｅＮｉ合金層６１と、第１光電変換セル１１となるＧｅ基板６２とを含んで構成されている。なお、Ｇｅ基板６２は、ｐ型Ｇｅ層、及びｎ型Ｇｅ層を含んでいる。
　第２光電変換セル１２に対応する第３積層体５８は、第１絶縁層１５となるノンドープのＩｎＧａＡｓ層７１、第１電極層３１となるｐ型のＩｎＧａＡｓＰ層７２、第２光電変換セル１２となるＩｎＧａＡｓ層７３を含んで構成されている。なお、ＩｎＧａＡｓ層７３は、ｐ型ＩｎＧａＡｓ層、及びｎ型ＩｎＧａＡｓ層を含んでいる。
　第３光電変換セル１３に対応する第４積層体５９は、第２絶縁層１６となるノンドープのＩｎＧａＰ層８１、第２電極層４１となるｐ型のＩｎＧａＡｓＰ層８２、及び第３光電変換セル１３となるＩｎＧａＰ層８３を含んで構成されている。なお、ＩｎＧａＰ層８３は、ｐ型ＩｎＧａＰ層、及びｎ型ＩｎＧａＰ層を含んでいる。 In FIG. 4A, the second stacked body 57 corresponding to the first photoelectric conversion cell 11 includes an AuGeNi alloy layer 61 to be the first electrode 21 and a Ge substrate 62 to be the first photoelectric conversion cell 11. Yes. The Ge substrate 62 includes a p-type Ge layer and an n-type Ge layer.
The third stacked body 58 corresponding to the second photoelectric conversion cell 12 includes a non-doped InGaAs layer 71 to be the first insulating layer 15, a p-type InGaAsP layer 72 to be the first electrode layer 31, the second photoelectric conversion cell 12, and The InGaAs layer 73 is formed. The InGaAs layer 73 includes a p-type InGaAs layer and an n-type InGaAs layer.
The fourth stacked body 59 corresponding to the third photoelectric conversion cell 13 includes a non-doped InGaP layer 81 serving as the second insulating layer 16, a p-type InGaAsP layer 82 serving as the second electrode layer 41, and the third photoelectric conversion cell 13. The InGaP layer 83 is formed. The InGaP layer 83 includes a p-type InGaP layer and an n-type InGaP layer.
　積層体５８，５９は、上記で説明した方法と同様、有機金属化学気相法等によって、各半導体層を順次積層することで形成することができる。 The laminated bodies 58 and 59 can be formed by sequentially laminating each semiconductor layer by a metal organic chemical vapor deposition method or the like, similar to the method described above.
　次に、これら各積層体５７，５８，５９を積層した状態でアニーリングを行うことで、各積層体５７，５８，５９を互いに接合させる。
　これにより。図４Ｂに示すように、各半導体層が積層された第１積層体５５が得られる。
　以降は、図３Ｃにて示した製造方法と同様の方法によって光発電素子１を得ることができる。 Next, annealing is performed in a state where these stacked bodies 57, 58, and 59 are stacked, thereby bonding the stacked bodies 57, 58, and 59 to each other.
By this. As shown in FIG. 4B, a first stacked body 55 in which the respective semiconductor layers are stacked is obtained.
Thereafter, the photovoltaic element 1 can be obtained by the same method as the manufacturing method shown in FIG. 3C.
　以上のように、本実施形態の光発電素子１は、第１光電変換セル１１、第２光電変換セル１２、及び第３光電変換セル１３を個別に形成し、これらを接合することによっても製造することができる。 As described above, the photovoltaic device 1 of the present embodiment is also manufactured by individually forming the first photoelectric conversion cell 11, the second photoelectric conversion cell 12, and the third photoelectric conversion cell 13, and joining them. can do.
〔第２実施形態について〕
　図５は、第２実施形態に係る光発電素子端部の平面図、図６は、図５中、ＶＩ－ＶＩ線矢視断面の一部を示す図であって、光発電素子１の端部断面を示している。
　本実施形態は、図６に示すように、２つの光電変換セルである第１光電変換セル１１１及び第２光電変換セル１１２を積層している点、及び第１光電変換セル１１１が、第１サブセル１２２及び第２サブセル１２９によって構成されている点において、第１実施形態と相違している。 [About the second embodiment]
FIG. 5 is a plan view of the end portion of the photovoltaic device according to the second embodiment, and FIG. 6 is a view showing a part of the cross section taken along line VI-VI in FIG. The cross section is shown.
In the present embodiment, as shown in FIG. 6, the first photoelectric conversion cell 111 and the second photoelectric conversion cell 112 that are two photoelectric conversion cells are stacked, and the first photoelectric conversion cell 111 is the first photoelectric conversion cell. The second embodiment is different from the first embodiment in that the subcell 122 and the second subcell 129 are configured.
　図６中、第１光電変換セル１１１と、第２光電変換セル１１２との間には、絶縁層１１５が介在している。
　この光発電素子１も第１実施形態と同様、平面視において矩形状とされており、その端部には、図６に示すように、光電変換セル１１１，１１２の端部によって段差が形成されている。 In FIG. 6, an insulating layer 115 is interposed between the first photoelectric conversion cell 111 and the second photoelectric conversion cell 112.
Similar to the first embodiment, this photovoltaic element 1 is also rectangular in plan view, and at its end, a step is formed by the ends of the photoelectric conversion cells 111 and 112 as shown in FIG. ing.
　第１光電変換セル１１１は、裏面側に設けられた第１サブセル１２２と、第１サブセル１２２上に積層された第２サブセル１２９と、両サブセル１２２，１２９を接合するトンネル接合層１２８とを含む。
　第１光電変換セル１１１は、層状に形成された第１電極１２１の表面に積層されている。第１電極１２１は、例えば、ＡｕＧｅＮｉ合金よりなる。 The first photoelectric conversion cell 111 includes a first subcell 122 provided on the back surface side, a second subcell 129 stacked on the first subcell 122, and a tunnel junction layer 128 that joins both the subcells 122 and 129. .
The 1st photoelectric conversion cell 111 is laminated | stacked on the surface of the 1st electrode 121 formed in the layer form. The first electrode 121 is made of, for example, an AuGeNi alloy.
　第１サブセル１２２は、裏面側に設けられたｐ型Ｇｅ層と、ｐ型Ｇｅ層上に設けられｐ型Ｇｅ層とｐｎ接合されたｎ型Ｇｅ層とを含む。
　第２サブセル１２９は、裏面側に設けられたｐ型ＩｎＧａＡｓ層と、ｐ型ＩｎＧａＡｓ層上に設けられｐ型ＩｎＧａＡｓ層とｐｎ接合されたｎ型ＩｎＧａＡｓ層とを含む。
　トンネル接合層１２８は、第１サブセル１２２と、第２サブセル１２９との間に介在して接合している。トンネル接合層１２８は、第１サブセル１２２側に設けられたｎ型ＩｎＧａＡｓ層と、第２サブセル１２９側に設けられたｐ型ＩｎＧａＡｓ層とを含む。 The first subcell 122 includes a p-type Ge layer provided on the back surface side, and an n-type Ge layer provided on the p-type Ge layer and pn-junctioned with the p-type Ge layer.
The second subcell 129 includes a p-type InGaAs layer provided on the back surface side, and an n-type InGaAs layer provided on the p-type InGaAs layer and pn-junctioned with the p-type InGaAs layer.
The tunnel junction layer 128 is interposed and joined between the first subcell 122 and the second subcell 129. Tunnel junction layer 128 includes an n-type InGaAs layer provided on the first subcell 122 side and a p-type InGaAs layer provided on the second subcell 129 side.
　第１光電変換セル１１１の表面は、絶縁層１１５が積層されている積層面１２３と、光の入射方向に露出している露出面１２４とを含む。
　露出面１２４は、図５に示すように、第１光電変換セル１１１の表面において互いに平行な２辺に沿う縁部両方に設けられている。
　露出面１２４には、第２電極１２５が設けられている。第２電極１２５は、両側の露出面１２４に形成されており、露出面１２４の長手方向に沿って線状に形成されている。第２電極１２５は、例えば、ＡｕＧｅＮｉ合金よりなる。
　第２電極１２５は、第１光電変換セル１１１の露出面１２４に設けられることで第１光電変換セル１１１のｎ側電極を構成している。
　また、第１電極１２１は、その表面上に第１光電変換セル１１１が積層されることで第１光電変換セル１１１のｐ側電極を構成している。 The surface of the first photoelectric conversion cell 111 includes a laminated surface 123 on which the insulating layer 115 is laminated and an exposed surface 124 exposed in the light incident direction.
As shown in FIG. 5, the exposed surface 124 is provided on both edges along two sides parallel to each other on the surface of the first photoelectric conversion cell 111.
A second electrode 125 is provided on the exposed surface 124. The second electrode 125 is formed on the exposed surfaces 124 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 124. The second electrode 125 is made of, for example, an AuGeNi alloy.
The second electrode 125 constitutes an n-side electrode of the first photoelectric conversion cell 111 by being provided on the exposed surface 124 of the first photoelectric conversion cell 111.
Moreover, the 1st electrode 121 comprises the p side electrode of the 1st photoelectric conversion cell 111 by laminating | stacking the 1st photoelectric conversion cell 111 on the surface.
　第２光電変換セル１１２は、絶縁層１１５の表面に積層された第１電極層１３１の表面に積層されている。つまり、第２光電変換セル１１２と、第１光電変換セル１１１とは、絶縁層１１５、及び第１電極層１３１を介して積層されている。 The second photoelectric conversion cell 112 is laminated on the surface of the first electrode layer 131 laminated on the surface of the insulating layer 115. That is, the second photoelectric conversion cell 112 and the first photoelectric conversion cell 111 are stacked with the insulating layer 115 and the first electrode layer 131 interposed therebetween.
　第１電極層１３１は、高濃度でドーピングされたｐ型のＩｎＧａＡｓＰ層で構成されている。なお、第１電極層１３１は、第１実施形態の第１電極層３１と同様の構成とされている。
　第１電極層１３１の表面は、第２光電変換セル１１２が積層されている積層面１３３と、光の入射方向に露出している露出面１３４とを含む。
　露出面１３４は、図５に示すように、第１電極層１３１の表面において露出面１２４に沿う２辺の縁部両方に設けられている。
　露出面１３４には、第３電極１３５が設けられている。第３電極１３５は、両側の露出面１３４に形成されており、露出面１３４の長手方向に沿って線状に形成されている。第３電極１３５は、例えば、ＡｕＧｅＮｉ合金よりなる。 The first electrode layer 131 is composed of a p-type InGaAsP layer doped at a high concentration. The first electrode layer 131 has the same configuration as the first electrode layer 31 of the first embodiment.
The surface of the first electrode layer 131 includes a stacked surface 133 on which the second photoelectric conversion cells 112 are stacked, and an exposed surface 134 exposed in the light incident direction.
As shown in FIG. 5, the exposed surface 134 is provided on both edges of the two sides along the exposed surface 124 on the surface of the first electrode layer 131.
A third electrode 135 is provided on the exposed surface 134. The third electrode 135 is formed on the exposed surfaces 134 on both sides, and is formed in a linear shape along the longitudinal direction of the exposed surface 134. The third electrode 135 is made of, for example, an AuGeNi alloy.
　第２光電変換セル１１２は、第１電極層１３１の表面上に設けられたｐ型ＩｎＧａＰ層と、ｐ型ＩｎＧａＰ層上に設けられｐ型ＩｎＧａＰ層とｐｎ接合されたｎ型ＩｎＧａＰ層とを含む。
　第２光電変換セル１１２の表面１３９には、第４電極１３８が設けられている。第４電極１３８は、両側の露出面１３４に沿う２辺に対して平行に延びているとともに表面１３９に所定間隔で並べられている線状の電極部を複数備えている。第４電極１３８は、例えば、ＡｕＧｅＮｉ合金よりなる。 The second photoelectric conversion cell 112 includes a p-type InGaP layer provided on the surface of the first electrode layer 131, and an n-type InGaP layer provided on the p-type InGaP layer and pn-junctioned with the p-type InGaP layer. .
A fourth electrode 138 is provided on the surface 139 of the second photoelectric conversion cell 112. The fourth electrode 138 includes a plurality of linear electrode portions that extend parallel to two sides along the exposed surfaces 134 on both sides and are arranged on the surface 139 at a predetermined interval. The fourth electrode 138 is made of, for example, an AuGeNi alloy.
　第４電極１３８は、第２光電変換セル１１２の表面１３９に設けられることで第２光電変換セル１１２のｎ側電極を構成している。
　また、第１電極層１３１は、その表面上に第２光電変換セル１１２が積層された状態でｐ型の半導体層を構成している。よって、第１電極層１３１及び第３電極１３５は、第２光電変換セル１１２のｐ側電極を構成している。 The fourth electrode 138 forms the n-side electrode of the second photoelectric conversion cell 112 by being provided on the surface 139 of the second photoelectric conversion cell 112.
The first electrode layer 131 forms a p-type semiconductor layer with the second photoelectric conversion cell 112 stacked on the surface thereof. Therefore, the first electrode layer 131 and the third electrode 135 constitute a p-side electrode of the second photoelectric conversion cell 112.
　絶縁層１１５は、ノンドープのＩｎＧａＰ層で構成されている。これにより、第１絶縁層１５は、第１光電変換セル１１と、第２光電変換セル１２の第１電極層３１との間を絶縁している。なお、絶縁層１１５は、第１実施形態の第１絶縁層１５及び第２絶縁層１６と同様の構成とされている。 The insulating layer 115 is composed of a non-doped InGaP layer. Thereby, the first insulating layer 15 insulates between the first photoelectric conversion cell 11 and the first electrode layer 31 of the second photoelectric conversion cell 12. The insulating layer 115 has the same configuration as the first insulating layer 15 and the second insulating layer 16 of the first embodiment.
　本実施形態の光発電素子１においても、第１実施形態と同様、絶縁層１１５を介して第１光電変換セル１１１と第２光電変換セル１１２とが積層されている。よって、第１光電変換セル１１１、及び第２光電変換セル１１２それぞれを独立した光発電素子として用いることができる。 Also in the photovoltaic device 1 of this embodiment, the 1st photoelectric conversion cell 111 and the 2nd photoelectric conversion cell 112 are laminated | stacked through the insulating layer 115 similarly to 1st Embodiment. Therefore, each of the first photoelectric conversion cell 111 and the second photoelectric conversion cell 112 can be used as an independent photovoltaic device.
　また、本実施形態では、第１光電変換セル１１を第１サブセル１２２及び第２サブセル１２９によって構成したので、光電変換セルの組み合わせの自由度を高めることができる。 Moreover, in this embodiment, since the 1st photoelectric conversion cell 11 was comprised by the 1st subcell 122 and the 2nd subcell 129, the freedom degree of the combination of a photoelectric conversion cell can be raised.
　なお、本実施形態の製造方法は、第１実施形態の製造方法と同様の方法によって製造することができる。 In addition, the manufacturing method of this embodiment can be manufactured by the same method as the manufacturing method of 1st Embodiment.
〔その他〕
　なお、今回開示された実施の形態はすべての点で例示であって制限的なものではないと考えられるべきである。
　上記各実施形態では、３つの光電変換セルを用いた場合を示したが、２つの光電変換セルで光発電素子１を構成してもよいし、４つ以上の光電変換セルを用いて光発電素子１を構成してもよい。 [Others]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive.
In each of the embodiments described above, the case where three photoelectric conversion cells are used has been described. However, the photovoltaic device 1 may be configured by two photoelectric conversion cells, or photovoltaic power generation using four or more photoelectric conversion cells. The element 1 may be configured.
　また、上記各実施形態では、絶縁層１５，１６，１１５として、ノンドープの半導体層（ＩｎＧａＡｓ層又はＩｎＧａＰ層）で構成した場合を例示したが、これに限定されるものではない。絶縁層の組成は、隣接する半導体層の組成に応じて適宜設定することができる。例えば、第１実施形態では、第２絶縁層１６をノンドープのＩｎＧａＰ層で構成したが、第２絶縁層１６に隣接する第２光電変換セル１２と同じ組成であるＩｎＧａＡｓ層で構成してもよい。 In each of the above embodiments, the insulating layers 15, 16, and 115 are configured by non-doped semiconductor layers (InGaAs layers or InGaP layers). However, the present invention is not limited to this. The composition of the insulating layer can be appropriately set according to the composition of the adjacent semiconductor layer. For example, in the first embodiment, the second insulating layer 16 is composed of a non-doped InGaP layer, but may be composed of an InGaAs layer having the same composition as that of the second photoelectric conversion cell 12 adjacent to the second insulating layer 16. .
　また、上記各実施形態では、絶縁層として半導体層をノンドープとしたものを用いた場合を例示したが、絶縁層は、介在する両側の光電変換セルを絶縁することができればよく、例えば、Ｆｅをドーピングした半導体層によって絶縁層を構成することもできる。 Further, in each of the above embodiments, the case where a semiconductor layer that is non-doped is used as the insulating layer is exemplified, but the insulating layer only needs to be able to insulate the photoelectric conversion cells on both sides, for example, Fe The insulating layer can also be constituted by a doped semiconductor layer.
　また、上記各実施形態では、光電変換セルとして、Ｇｅ層によるＧｅセル、ＩｎＧａＡｓ層によるＩｎＧａＡｓセル、ＩｎＧａＰ層によるＩｎＧａＰセルを用いた場合を示したが、これに限定されるわけではなく、他の半導体材料による光電変換セルを用いることもできる。 In each of the above embodiments, the case where a Ge cell using a Ge layer, an InGaAs cell using an InGaAs layer, or an InGaP cell using an InGaP layer is used as the photoelectric conversion cell. However, the present invention is not limited to this. A photoelectric conversion cell made of a semiconductor material can also be used.
　また、上記各実施形態では、電極層３１，４１，１３１を高濃度でドーピングした半導体層（ＩｎＧａＡｓＰ層）で構成した場合を例示したが、例えば、ＡｕＧｅＮｉ合金等の金属で電極層を形成してもよい。 In each of the above embodiments, the electrode layers 31, 41 and 131 are exemplified by the semiconductor layer (InGaAsP layer) doped at a high concentration. For example, the electrode layer is formed of a metal such as an AuGeNi alloy. Also good.
　本発明の範囲は、上記した意味ではなく、請求の範囲によって示され、請求の範囲と均等の意味、及び範囲内でのすべての変更が含まれることが意図される。 The scope of the present invention is shown not by the above-mentioned meaning but by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications within the scope.
　１　光発電素子
　１１　第１光電変換セル
　１２　第２光電変換セル
　１３　第３光電変換セル
　１５　第１絶縁層
　１６　第２絶縁層
　２１　第１電極
　２３　積層面
　２４　露出面
　２５　第２電極
　３１　第１電極層
　３３　積層面
　３４　露出面
　３５　第３電極
　３６　積層面
　３７　露出面
　３８　第４電極
　４１　第２電極層
　４３　積層面
　４４　露出面
　４５　第５電極
　４６　第６電極
　４７　表面
　５１　ＡｕＧｅＮｉ合金層
　５２　Ｇｅ基板
　５５　第１積層体
　５７　第２積層体
　５８　第３積層体
　５９　第４積層体
　６１　ＡｕＧｅＮｉ合金層
　６２　Ｇｅ基板
　１１１　第１光電変換セル
　１１２　第２光電変換セル
　１１５　絶縁層
　１２１　第１電極
　１２２　第１サブセル
　１２３　積層面
　１２４　露出面
　１２５　第２電極
　１２８　トンネル接合層
　１２９　第２サブセル
　１３１　第１電極層
　１３３　積層面
　１３４　露出面
　１３５　第３電極
　１３８　第４電極
　１３９　表面
　Ｉ１，Ｉ２，Ｉ３　インバータ DESCRIPTION OF SYMBOLS 1 Photoelectric power generation element 11 1st photoelectric conversion cell 12 2nd photoelectric conversion cell 13 3rd photoelectric conversion cell 15 1st insulating layer 16 2nd insulating layer 21 1st electrode 23 Laminated surface 24 Exposed surface 25 2nd electrode 31 1st electrode Layer 33 Laminated surface 34 Exposed surface 35 Third electrode 36 Laminated surface 37 Exposed surface 38 Fourth electrode 41 Second electrode layer 43 Laminated surface 44 Exposed surface 45 Fifth electrode 46 Sixth electrode 47 Surface 51 AuGeNi alloy layer 52 Ge substrate 55 First laminated body 57 Second laminated body 58 Third laminated body 59 Fourth laminated body 61 AuGeNi alloy layer 62 Ge substrate 111 First photoelectric conversion cell 112 Second photoelectric conversion cell 115 Insulating layer 121 First electrode 122 First subcell 123 Laminated surface 124 Exposed surface 125 Second electrode 128 Tunnel junction layer 129 Second subcell 131 First electrode layer 133 Laminated surface 13 Exposed surface 135 third electrode 138 fourth electrode 139 surface I1, I2, I3 inverter

Claims (6)

  1. 　少なくとも、第１光電変換セルと、第２光電変換セルと、を含む光発電素子であって、
    　前記第１光電変換セルと、前記第２光電変換セルとは、前記第１光電変換セルと前記第２光電変換セルとを絶縁する絶縁層を介して積層されている
    光発電素子。     A photovoltaic device including at least a first photoelectric conversion cell and a second photoelectric conversion cell,
    The first photoelectric conversion cell and the second photoelectric conversion cell are photovoltaic elements that are stacked via an insulating layer that insulates the first photoelectric conversion cell and the second photoelectric conversion cell.
  2. 　前記第１光電変換セル及び前記第２光電変換セルのそれぞれに、ｐ側電極及びｎ側電極が設けられている
    請求項１に記載の光発電素子。     The photovoltaic device according to claim 1, wherein a p-side electrode and an n-side electrode are provided in each of the first photoelectric conversion cell and the second photoelectric conversion cell.
  3. 　前記第１光電変換セル及び前記第２光電変換セルのうちのいずれか一方と、前記絶縁層との間には、前記ｐ側電極又は前記ｎ側電極のいずれか一方を構成する電極層が設けられている
    請求項２に記載の光発電素子。     An electrode layer constituting either the p-side electrode or the n-side electrode is provided between any one of the first photoelectric conversion cell and the second photoelectric conversion cell and the insulating layer. The photovoltaic device according to claim 2.
  4. 　前記絶縁層は、ノンドープ層である
    請求項１から請求項３の少なくともいずれか一項に記載の光発電素子。     The photovoltaic device according to any one of claims 1 to 3, wherein the insulating layer is a non-doped layer.
  5. 　前記第１光電変換セル及び前記第２光電変換セルの内、少なくともいずれか一方が複数のサブセルを接合して構成されている
    請求項１から請求項４の少なくともいずれか一項に記載の光発電素子。     5. The photovoltaic power generation according to claim 1, wherein at least one of the first photoelectric conversion cell and the second photoelectric conversion cell is configured by joining a plurality of subcells. 6. element.
  6. 　前記第１光電変換セル及び前記第２光電変換セルの内、少なくともいずれか一方が化合物半導体からなる
    請求項１から請求項５の少なくともいずれか一項に記載の光発電素子。
          6. The photovoltaic device according to claim 1, wherein at least one of the first photoelectric conversion cell and the second photoelectric conversion cell is made of a compound semiconductor.
PCT/JP2018/014309 2017-06-08 2018-04-03 Photovoltaic generation element WO2018225361A1 (en)

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Citations (4)

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JP2009510719A (en) * 2005-09-26 2009-03-12 インペリアル イノベーションズ リミテッド Photovoltaic cell
US20110174366A1 (en) * 2007-03-06 2011-07-21 Sunlight Photonics Inc. Spectrally adaptive multijunction photovoltaic thin film device and method of producing same
JP2012151471A (en) * 2011-01-18 2012-08-09 Sharp Corp Mechanical stacking structure for multi-junction photovoltaic devices and method of making the same
US20140261628A1 (en) * 2013-03-14 2014-09-18 Semprius, Inc. High efficiency solar receivers including stacked solar cells for concentrator photovoltaics

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009510719A (en) * 2005-09-26 2009-03-12 インペリアル イノベーションズ リミテッド Photovoltaic cell
US20110174366A1 (en) * 2007-03-06 2011-07-21 Sunlight Photonics Inc. Spectrally adaptive multijunction photovoltaic thin film device and method of producing same
JP2012151471A (en) * 2011-01-18 2012-08-09 Sharp Corp Mechanical stacking structure for multi-junction photovoltaic devices and method of making the same
US20140261628A1 (en) * 2013-03-14 2014-09-18 Semprius, Inc. High efficiency solar receivers including stacked solar cells for concentrator photovoltaics

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