WO2012090849A1 - Solar cell string and solar cell module - Google Patents

Solar cell string and solar cell module Download PDF

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Publication number
WO2012090849A1
WO2012090849A1 PCT/JP2011/079777 JP2011079777W WO2012090849A1 WO 2012090849 A1 WO2012090849 A1 WO 2012090849A1 JP 2011079777 W JP2011079777 W JP 2011079777W WO 2012090849 A1 WO2012090849 A1 WO 2012090849A1
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Prior art keywords
type
solar cell
electrode
silicon substrate
wiring
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PCT/JP2011/079777
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French (fr)
Japanese (ja)
Inventor
諭 岡本
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シャープ株式会社
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Publication of WO2012090849A1 publication Critical patent/WO2012090849A1/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
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/05—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells
    • H01L31/0504—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells specially adapted for series or parallel connection of solar cells in a module
    • H01L31/0516—Electrical interconnection means between PV cells inside the PV module, e.g. series connection of PV cells specially adapted for series or parallel connection of solar cells in a module specially adapted for interconnection of back-contact solar cells
    • 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
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
    • H01L31/022441—Electrode arrangements specially adapted for back-contact solar cells
    • 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
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
    • H01L31/022441—Electrode arrangements specially adapted for back-contact solar cells
    • H01L31/022458—Electrode arrangements specially adapted for back-contact solar cells for emitter wrap-through [EWT] type solar cells, e.g. interdigitated emitter-base back-contacts
    • 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
    • Y02E10/547—Monocrystalline silicon PV cells

Definitions

  • the present invention relates to a solar cell string and a solar cell module.
  • the most manufactured and sold solar cells have a structure in which electrodes are formed on a light receiving surface which is a surface on the incident light side and a back surface which is a surface opposite to the light receiving surface.
  • the solar cell module is obtained by electrically connecting a plurality of solar cells to form a solar cell string, and sealing the solar cell string with a resin or the like.
  • FIG. 15 is a diagram showing a back electrode type solar cell (hereinafter also referred to as “solar cell”) disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2005-340362).
  • FIG. 15 (a) shows a schematic plan view of the back electrode type solar cell disclosed in Patent Document 1 as seen from the back side
  • FIG. 15 (b) shows a G- The typical sectional view which looked at the section along G 'from the direction of the arrow is shown. As shown in FIGS.
  • an n electrode 102 and a p electrode 103 are formed on the back surface of the silicon substrate 121 of the solar battery cell 101, and the silicon substrate 121 of the solar battery cell 101 has A comb-shaped n + layer 104 and a comb-shaped p + layer 105 are formed on the back side.
  • An n electrode 102 is formed on the n + layer 104, and a p electrode 103 is formed on the p + layer 105.
  • FIG. 16 is a schematic plan view of a wiring board for connecting solar cells disclosed in Patent Document 1.
  • FIG. Here, on the surface of the insulating substrate 116 of the wiring substrate 106, an n wiring 107 for connecting to the n electrode 102 of the solar battery cell 101 and a p wiring 108 for connecting to the p electrode 103 of the solar battery cell 101.
  • a connection wiring 109 for electrically connecting the n wiring 107 and the p wiring 108 is formed.
  • FIG. 17 is a schematic plan view of a solar cell string 110 in which a plurality of solar cells 101 are arranged on the wiring substrate 106 as viewed from the light receiving surface side.
  • the connection wiring 109 is not shown for convenience of explanation.
  • solar cell string 110 a plurality of solar cells are connected such that n electrode 102 and p electrode 103 of solar cell 101 are electrically connected to n wiring 107 and p wiring 108 of wiring substrate 106, respectively.
  • Battery cell 101 is arranged.
  • FIG. 18 is a schematic plan view of a solar cell string 110 in which solar cells 101 electrically connected in series are arranged in a plurality of rows as viewed from the light receiving surface side.
  • the solar cell string 110 includes two rows of solar cell cells 101 arranged in series on the wiring substrate 106.
  • the connection wiring 109 is not shown for convenience of explanation.
  • FIG. 19 is a schematic cross-sectional view of the cross section taken along the line H-H ′ of FIG. 18 as viewed from the direction of the arrow.
  • an electrode having the same conductivity type as that of the silicon substrate 121 has the same potential as that of the silicon substrate 121, but an electrode having a conductivity type different from that of the silicon substrate 121 has a potential difference generated at the pn junction.
  • the conductivity type of the silicon substrate 121 is n-type
  • the n electrode 102 and the silicon substrate 121 have the same potential
  • the p electrode 103 and the silicon substrate 121 have a potential difference generated at the pn junction.
  • the silicon substrate 121 and the n electrode 102 have the same potential, but the silicon substrate 121 and the p electrode 103 have a potential difference.
  • the potential distribution in the thickness direction of the solar battery cells 101 is different at the end portions of the solar battery cells 101 of the adjacent solar battery cells 101, so that the potential distribution is biased between the adjacent solar battery cells 101. Then, as the interval between adjacent solar cells 101 is narrower, the bias of the potential distribution affects the characteristics of the solar cells 101, and the characteristics of the solar cell string 110 may be deteriorated.
  • FIG. 20 is a schematic enlarged cross-sectional view of a solar cell string in which the conductivity type of the electrode closest to the end of the adjacent solar cell 101 is different from the conductivity type of the silicon substrate 121 (in this case, n-type). is there.
  • the potential difference between the silicon substrate 121 and the electrode is the same between adjacent solar cells 101, but the potential distribution in the thickness direction of the solar cells 101 at the end of each solar cell 101.
  • the potential distribution is biased between the solar battery cell 101 and the outside thereof.
  • the bias of the potential distribution may affect the characteristics of the solar battery cell 101, and the characteristics of the solar battery string 110 may be deteriorated.
  • an object of the present invention is to provide a solar cell string and a solar cell capable of suppressing a deterioration in the characteristics of the solar cell string due to a bias in potential distribution in the thickness direction of end portions of adjacent solar cells.
  • the object is to provide a battery module.
  • the present invention includes a back electrode type solar battery cell that is arranged in a plurality in each of a first direction and a second direction orthogonal to the first direction.
  • the back electrode type solar battery cell includes a silicon substrate and a silicon substrate. Having a first conductivity type electrode and a second conductivity type electrode provided on the back surface opposite to the light receiving surface, and the first conductivity type electrode is disposed along the first direction of the back surface of the silicon substrate.
  • the second conductivity type electrode is disposed at a distance from the first conductivity type electrode along the first direction of the back surface of the silicon substrate, and the back electrode type solar cells adjacent in the second direction are
  • the solar cell string is arranged such that the electrodes closest to the end portions of the back electrode type solar cells are of the same conductivity type.
  • the silicon substrate is preferably the first conductivity type
  • the electrode closest to the end of the back electrode type solar cell is preferably the first conductivity type electrode
  • the back electrode type solar cell has a light receiving surface impurity semiconductor layer formed on the light receiving surface of the silicon substrate.
  • the electrode closest to the end of the back electrode type solar cell is electrically connected to the light-receiving surface impurity semiconductor layer.
  • the solar cell string of the present invention further includes a wiring substrate, the back electrode type solar cell is disposed on the wiring substrate, and the wiring substrate is for the first conductivity type wiring and the second conductivity type.
  • the first conductivity type electrode is electrically connected to the first conductivity type wire
  • the second conductivity type electrode is electrically connected to the second conductivity type wire.
  • the present invention is a solar cell module including any one of the above solar cell strings, a transparent base material, and a sealing material between the solar cell string and the transparent base material.
  • the solar cell string and solar cell module which can suppress the fall of the characteristic of a solar cell string by the bias of the electric potential distribution in the thickness direction of the edge part of an adjacent photovoltaic cell are provided. it can.
  • FIG. 3 is a schematic plan view of an example of a wiring substrate used for the solar cell string in the first embodiment. It is a typical top view when the solar cell string of Embodiment 1 is seen from the light-receiving surface side.
  • FIG. 4 is a schematic cross-sectional view taken along the line B-B ′ of FIG. 3 as viewed from the direction of the arrow.
  • FIG. 6 is a schematic cross-sectional view taken along the line C-C ′ of FIG. 5 as viewed from the direction of the arrow.
  • (A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 3 from the back surface side
  • (b) is LL of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow. It is a typical top view when the solar cell string of Embodiment 3 is seen from the light-receiving surface side.
  • FIG. 9 is a schematic cross-sectional view taken along the line M-M ′ of FIG. 8 as viewed from the direction of the arrow.
  • (A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 4 from the back surface side
  • (b) is DD of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow.
  • FIG. 10 is a schematic plan view of an example of a wiring substrate used for the solar cell string in the fourth embodiment. It is a typical top view when the solar cell string of Embodiment 4 is seen from the light-receiving surface side.
  • FIG. 13 is a schematic cross-sectional view taken along the line E-E ′ of FIG.
  • FIG. 12 is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 5 from the back surface side
  • (b) is FF of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow.
  • (A) is the typical top view which looked at the back electrode type photovoltaic cell currently indicated by patent documents 1 from the back side
  • (b) is a section along GG 'of (a). It is typical sectional drawing which looked at from the direction of the arrow. It is a typical top view of the wiring board for connecting the photovoltaic cell currently disclosed by patent document 1.
  • FIG. 1 is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 5 from the back surface side
  • (b) is FF of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow.
  • (A) is the typical top view
  • FIG. 19 is a schematic cross-sectional view taken along the line H-H ′ of FIG. 18 as viewed from the direction of the arrows. It is a typical expanded sectional view of the solar cell string from which the conductivity type of the electrode nearest to the edge part of an adjacent photovoltaic cell differs from the conductivity type of a silicon substrate.
  • FIG. 1A shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar cell string of the first embodiment as viewed from the back side
  • FIG. 3A is a schematic cross-sectional view of a cross section taken along line AA ′ in a) when viewed from the direction of an arrow.
  • a plurality of dot-shaped electrodes 2 for n-type are formed in the first direction (on the back surface opposite to the light receiving surface of the n-type silicon substrate 21 of the back-electrode solar cell 1 in the first direction (
  • a row of n-type electrodes 2 is formed by being arranged in a line in each direction of the n-type silicon substrate 21 (one side direction) and the second direction (the other one-side direction of the n-type silicon substrate 21).
  • a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type.
  • a row of electrodes 3 is formed.
  • the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one.
  • the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. It is.
  • first direction and the second direction are orthogonal to each other.
  • the angle formed by the first direction and the second direction may be substantially 90 °.
  • an n-type semiconductor region 4 and a p-type semiconductor region 5 are formed on the back surface of the n-type silicon substrate 21, and an n-type electrode 2 is formed on the n-type semiconductor region 4.
  • the p-type electrode 3 is formed on the p-type semiconductor region 5.
  • the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed in a line shape along the column of the n-type electrode 2 and the column of the p-type electrode 3, respectively.
  • the light receiving surface of the n-type silicon substrate 21 is a surface on the side where incident light is incident, and the back surface of the n-type silicon substrate 21 is a surface opposite to the light receiving surface.
  • the electrode formed at the end portion of the back surface of the n-type silicon substrate 21 in the second direction of the back-surface electrode type solar cell 1 shown in FIGS. 1A and 1B is an n-type electrode 2.
  • the n-type semiconductor regions 4 and the p-type semiconductor regions 5 do not necessarily have to be formed alternately.
  • the n-type electrode 2 and the p-type electrode 3 may be formed in an integrated line shape for each row of the n-type electrode 2 and each row of the p-type electrode 3.
  • FIG. 2 shows a schematic plan view of an example of a wiring substrate used in the solar cell string of the first embodiment.
  • the wiring substrate 6 electrically connects the insulating substrate 16, the n wiring 7 and the p wiring 8 provided on the surface of the insulating substrate 16, and the n wiring 7 and the p wiring 8. Connection wiring 9 is provided.
  • the insulating base 16 is an insulator having a shape such as a sheet shape or a substrate shape.
  • n wiring 7 and the p wiring 8 are each formed in a line shape on the surface of the insulating base material 16 of the wiring base material 6. Further, the n wiring 7 and the p wiring 8 are arranged one by one in the second direction alternately at a predetermined interval.
  • the connection wiring 9 is formed in a rectangular shape extending in the second direction. The connection wiring 9 is electrically connected to one end of each n wiring 7 arranged in the second direction and / or one end of each p wiring 8 arranged in the second direction.
  • FIG. 3 shows a schematic plan view of the solar cell string of the first embodiment when viewed from the light receiving surface side.
  • the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively.
  • the back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction.
  • the connection wiring 9 is not shown for convenience of explanation.
  • FIG. 4 shows a schematic cross-sectional view of the cross-section along B-B ′ of FIG. 3 as seen from the direction of the arrow.
  • the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1.
  • the electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
  • the electrodes closest to the facing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 which are electrodes of the same conductivity type.
  • the n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for the same conductivity type as the n-type silicon substrate 21 (in this case, for n-type).
  • the potential is the same as that of the n-type silicon substrate 21, and no potential distribution is generated in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1. Therefore, the potential distribution generated between the back electrode type solar cells 1 adjacent in the second direction does not change in the thickness direction of the back electrode type solar cell 1, and the potential distribution is not biased.
  • Embodiment 1 since the fall of the characteristic by the bias of the electric potential distribution in the thickness direction of the edge part of the adjacent back electrode type photovoltaic cell 1 can be suppressed, the characteristic of the solar cell string 10 is suppressed. The decrease can be suppressed.
  • FIG. 5 the typical top view when the solar cell string of Embodiment 2 is seen from the light-receiving surface side is shown.
  • the solar cell string 10 of the second embodiment is characterized in that three back electrode type solar cells 1 are arranged on the wiring base 6 in the first direction and in the second direction, respectively. There is.
  • the back electrode type solar cells 1 are connected in series along the first direction, and three of the back electrode type solar cells 1 connected in series are predetermined in the second direction. It is installed in parallel with a gap.
  • the connection wiring 9 is not shown for convenience of explanation.
  • FIG. 6 shows a schematic cross-sectional view of the cross-section along C-C ′ of FIG. 5 as seen from the direction of the arrow.
  • the electrodes closest to the opposing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type.
  • the n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for the same conductivity type (in this case, n-type) as the n-type silicon substrate 21,
  • the potential is the same as that of the n-type silicon substrate 21, and no potential distribution is generated in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1.
  • the characteristics of the solar cell string 10 are deteriorated. Can be suppressed.
  • the case where an n-type silicon substrate is used has been described.
  • a p-type silicon substrate can also be used.
  • the electrodes closest to the end portion of the back electrode type solar cell 1 at the opposite end portions of the back electrode type solar cells 1 adjacent in the second direction are both the same. It becomes the electrode 3 for p-types which is an electrode for conductivity types.
  • the other structure is the same as that when an n-type silicon substrate is used.
  • the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when a p-type silicon substrate is used.
  • FIG. 7A shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar cell string of Embodiment 3, as viewed from the back side
  • FIG. FIG. 3A is a schematic cross-sectional view of a cross section taken along line LL ′ of a) when viewed from the direction of an arrow.
  • the third embodiment is characterized in that an n-type semiconductor region 13 that is a light-receiving surface impurity semiconductor layer is formed on the light-receiving surface of the n-type silicon substrate 21 of the back electrode type solar cell 1.
  • a plurality of dot-shaped electrodes 2 are arranged in the first direction (on the back surface opposite to the light receiving surface of the n-type silicon substrate 21 of the back-electrode solar cell 1 in the first direction (
  • a row of n-type electrodes 2 is formed by being arranged in a line in each direction of the n-type silicon substrate 21 (one side direction) and the second direction (the other one-side direction of the n-type silicon substrate 21).
  • a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type.
  • a row of electrodes 3 is formed.
  • the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one.
  • the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
  • first direction and the second direction are orthogonal to each other.
  • the angle formed by the first direction and the second direction may be substantially 90 °.
  • the light receiving surface of the n-type silicon substrate 21 of the back electrode type solar cell 1 has an FSF (Front Surface Field) which is an n-type semiconductor region 13 as a light-receiving surface impurity semiconductor layer. A layer is formed.
  • FSF Front Surface Field
  • each of the n-type semiconductor region 4 and the n-type semiconductor region 13 has an n-type impurity concentration higher than that of the n-type silicon substrate 21.
  • the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line on the back surface of the n-type silicon substrate 21 of the back electrode type solar cell 1 is the n-type electrode 2. Further, the columns of the n-type electrodes 2 and the columns of the p-type electrodes 3 are alternately arranged one by one. In addition, a plurality of dot-type p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at predetermined intervals from the arrangement of the n-type electrodes 2, and the p-type electrode 3. Form a column.
  • the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the n-type silicon substrate 21, and the n-type electrode 2 is formed on the n-type semiconductor region 4.
  • the p-type electrode 3 is formed on the p-type semiconductor region 5.
  • the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed in a line shape along the column of the n-type electrode 2 and the column of the p-type electrode 3, respectively.
  • the light receiving surface of the n-type silicon substrate 21 is a surface on the side where incident light is incident, and the back surface of the n-type silicon substrate 21 is a surface opposite to the light receiving surface.
  • the electrode formed at the end of the back surface of the n-type silicon substrate 21 in the second direction of the back-surface electrode type solar cell 1 shown in FIGS. 7A and 7B is the n-type electrode 2.
  • the n-type semiconductor regions 4 and the p-type semiconductor regions 5 do not necessarily have to be formed alternately.
  • the n-type electrode 2 and the p-type electrode 3 may be formed in an integrated line shape for each row of the n-type electrode 2 and each row of the p-type electrode 3.
  • FIG. 8 shows a schematic plan view of the solar cell string of the third embodiment when viewed from the light receiving surface side.
  • the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively.
  • the back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction.
  • the connection wiring 9 is not shown for convenience of explanation.
  • FIG. 9 is a schematic cross-sectional view of the cross section taken along the line M-M ′ of FIG. 8 as seen from the direction of the arrow.
  • the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1.
  • the electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
  • the electrodes closest to the opposing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type.
  • the n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 has the same potential as the n type semiconductor region 13 on the light receiving surface of the n type silicon substrate 21, and the end of the back electrode type solar cell 1. In the portion, no potential distribution is generated in the thickness direction of the back electrode type solar cell 1. Therefore, the potential distribution generated between the back electrode type solar cells 1 adjacent in the second direction does not change in the thickness direction of the back electrode type solar cell 1, and the potential distribution is not biased.
  • Embodiment 3 since the fall of the characteristic by the bias of the electric potential distribution in the thickness direction of the edge part of the adjacent back electrode type solar cell 1 can be suppressed, the characteristic of the solar cell string 10 is suppressed. The decrease can be suppressed.
  • the case where an n-type silicon substrate is used has been described.
  • a p-type silicon substrate can also be used.
  • the electrodes closest to the end portion of the back electrode type solar cell 1 at the opposite end portions of the back electrode type solar cells 1 adjacent in the second direction are both the same.
  • a p-type electrode 3 which is an electrode for conductivity type is formed, and a p-type semiconductor region having an impurity concentration higher than that of the p-type silicon substrate is formed on the light receiving surface of the p-type silicon substrate.
  • the other structure is the same as that when an n-type silicon substrate is used.
  • the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when a p-type silicon substrate is used.
  • a back electrode type solar cell in which the electrode arranged on the outermost side in the second direction using an n-type silicon substrate is an n-type electrode, and a p-type silicon substrate are used.
  • the back electrode type solar cell in which the electrode arranged on the outermost side in the second direction is a p-type electrode may be adjacent in the second direction.
  • FIG. 10 (a) shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar battery string of Embodiment 4 as seen from the back side
  • FIG. 10 (b) shows a plan view of FIG. FIG. 3A is a schematic cross-sectional view of a cross-section along DD ′ in a) when viewed from the direction of an arrow.
  • the fourth embodiment is characterized in that the back electrode type solar cell 1 is an EWT (Emitter Wrap Through) type back electrode type solar cell.
  • EWT Emitter Wrap Through
  • a plurality of dot-like electrodes 2 for n-type are arranged in the first direction (one of the p-type silicon substrate 521.
  • a row of n-type electrodes 2 is formed by being arranged in a line in the respective directions of the side direction) and the second direction (the other one side direction of the p-type silicon substrate 521).
  • a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type.
  • a row of electrodes 3 is formed.
  • the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one.
  • the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
  • first direction and the second direction are orthogonal to each other.
  • the angle formed by the first direction and the second direction may be substantially 90 °.
  • the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the p-type silicon substrate 521, and the n-type electrode 2 is formed on the n-type semiconductor region 4.
  • the p-type electrode 3 is formed on the p-type semiconductor region 5.
  • the n-type semiconductor region 4 extends from the back surface of the p-type silicon substrate 521 through a part of the p-type silicon substrate 521 to the entire light receiving surface of the p-type silicon substrate 521. That is, among the electrodes arranged in a line on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the n-type electrode 2 arranged on the outermost side in the second direction is p-type.
  • the silicon substrate 521 is electrically connected to the n-type semiconductor region 4 on the light receiving surface.
  • FIG. 11 shows a schematic plan view of an example of a wiring substrate used in the solar cell string of the fourth embodiment.
  • the wiring substrate 6 electrically connects the insulating substrate 16, the n wiring 7 and the p wiring 8 provided on the surface of the insulating substrate 16, and the n wiring 7 and the p wiring 8. Connection wiring 9 is provided.
  • the insulating base 16 is an insulator having a shape such as a sheet shape or a substrate shape.
  • n wiring 7 and the p wiring 8 are each formed in a line shape on the surface of the insulating base material 16 of the wiring base material 6. Further, the n wiring 7 and the p wiring 8 are arranged one by one in the second direction alternately at a predetermined interval.
  • the connection wiring 9 is formed in a rectangular shape extending in the second direction. The connection wiring 9 is electrically connected to one end of each n wiring 7 arranged in the second direction and / or one end of each p wiring 8 arranged in the second direction.
  • FIG. 12 shows a schematic plan view of the solar cell string of the fourth embodiment when viewed from the light receiving surface side.
  • the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively.
  • the back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction.
  • the connection wiring 9 is not shown for convenience of explanation.
  • FIG. 13 is a schematic cross-sectional view of the cross section taken along the line E-E ′ of FIG. 12 as seen from the direction of the arrow.
  • the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1.
  • the electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
  • the electrodes closest to the facing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type.
  • the n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for a conductivity type different from the p-type silicon substrate 521 (in this case, for p-type).
  • the n-type semiconductor region 4 on the light receiving surface of the silicon substrate 521 have the same potential, and the potential distribution in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1 is symmetric. .
  • the potential distribution generated between the end portions of the back electrode type solar cells 1 adjacent in the second direction is symmetrical at the end portions of the back electrode type solar cells 1 serving as the boundary region.
  • the solar cell 1 does not change in the thickness direction, and the potential distribution is not biased. Therefore, the bias of the potential distribution between the back electrode type solar cell 1 and the outside thereof can be suppressed. Accordingly, it is possible to suppress the deterioration of the characteristics of the solar cell string 10 caused by the back electrode type solar cell 1.
  • FIG. 14 (a) shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar battery string of Embodiment 5 as seen from the back side
  • FIG. 14 (b) shows FIG.
  • FIG. 3A is a schematic cross-sectional view of a cross section taken along the line FF ′ of a) when viewed from the direction of an arrow.
  • the fifth embodiment is characterized in that the back electrode type solar cell 1 is an MWT (Metal Wrap Through) type back electrode type solar cell.
  • a plurality of dot-like electrodes 2 for n-type are arranged in the first direction (one of the p-type silicon substrate 521 A row of n-type electrodes 2 is formed by being arranged in a line in the respective directions of the side direction) and the second direction (the other one side direction of the p-type silicon substrate 521).
  • a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type.
  • a row of electrodes 3 is formed.
  • the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one.
  • the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
  • first direction and the second direction are orthogonal to each other.
  • the angle formed by the first direction and the second direction may be substantially 90 °.
  • the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the p-type silicon substrate 521, and the n-type electrode 2 is formed on the n-type semiconductor region 4.
  • the p-type electrode 3 is formed on the p-type semiconductor region 5.
  • the n-type semiconductor region 4 extends from the back surface of the p-type silicon substrate 521 through a part of the p-type silicon substrate 521 to the entire light receiving surface of the p-type silicon substrate 521.
  • the n-type electrode 2 also passes through the inside of a part of the p-type silicon substrate 521 from the back surface of the p-type silicon substrate 521 and is electrically connected to the n-type semiconductor region 4 on the light-receiving surface of the p-type silicon substrate 521. It is connected to the. That is, among the electrodes arranged in a line on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the n-type electrode 2 arranged on the outermost side in the second direction is p-type. The silicon substrate 521 is electrically connected to the n-type semiconductor region 4 on the light receiving surface.
  • the solar cell string is formed using the MWT type back electrode type solar cell 1
  • the same structure as that of the solar cell string according to the fourth embodiment using the EWT type back electrode type solar cell 1 is taken.
  • the same effect as that of the solar cell string of the fourth embodiment can be obtained.
  • the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when an n-type silicon substrate is used.
  • the solar cell string in which the back electrode type solar cells are connected using the wiring base material has been described.
  • the back electrode type solar cells are connected to each other by an interconnector. Even when the battery string is formed, the same effect as described above can be obtained.
  • an interconnector what was formed with the metal material which electrically connects between back electrode type solar cells, for example can be used.
  • the present invention can be used for solar cell strings and solar cell modules.
  • 1 back electrode type solar cell 2 n type electrode, 3 p type electrode, 4 n type semiconductor region, 5 p type semiconductor region, 6 wiring substrate, 7 n wiring, 8 p wiring, 9 connection wiring, 10
  • Solar cell string 13 n-type semiconductor region, 16 insulating substrate, 21 n-type silicon substrate, 521 p-type silicon substrate, 101 solar cell, 102 n-electrode, 103 p-electrode, 104 n + layer, 105 p + layer 106 wiring board, 107 n wiring, 108 p wiring, 109 connection wiring, 110 solar cell string, 116 insulating substrate, 121 silicon substrate.

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Abstract

The present invention is a solar cell string (10) that includes back surface electrode type solar cells (1) a plurality of which is disposed in each of a first direction and a second direction perpendicular to the first direction. The back surface electrode type solar cells (1) adjacent in the second direction are disposed such that the electrodes closest to the end parts of the back surface electrode type solar cells (1) are of the same conduction type as each other. The present invention is also a solar cell module that contains this solar cell string.

Description

太陽電池ストリングおよび太陽電池モジュールSolar cell string and solar cell module
　本発明は、太陽電池ストリングおよび太陽電池モジュールに関する。 The present invention relates to a solar cell string and a solar cell module.
　太陽光エネルギを直接電気エネルギに変換する太陽電池セルは、近年、特に地球環境問題の観点から、次世代のエネルギ源としての期待が急激に高まっている。太陽電池セルとしては、化合物半導体または有機材料を用いたものなど様々な種類があるが、現在主流となっているのは、シリコン結晶を用いたものである。 In recent years, solar cells that directly convert solar energy into electrical energy have been rapidly expected as next-generation energy sources, particularly from the viewpoint of global environmental problems. There are various types of solar cells, such as those using compound semiconductors or organic materials, but the mainstream is currently using silicon crystals.
　現在、最も多く製造および販売されている太陽電池セルは、入射光側の面である受光面と、受光面の反対側の面である裏面とに電極が形成された構造のものである。 At present, the most manufactured and sold solar cells have a structure in which electrodes are formed on a light receiving surface which is a surface on the incident light side and a back surface which is a surface opposite to the light receiving surface.
　しかしながら、受光面に電極を形成した場合、電極における光の反射および吸収があることから、形成された電極の面積分だけ入射する太陽光が減少するため、裏面にのみ電極が形成された裏面電極型太陽電池セルが開発されており、裏面電極型太陽電池セルを用いた太陽電池モジュールも開発されている。太陽電池モジュールは、複数の太陽電池セルを電気的に接続して太陽電池ストリングとし、その太陽電池ストリングを樹脂等で封止したものである。 However, when an electrode is formed on the light receiving surface, since there is reflection and absorption of light at the electrode, the incident sunlight is reduced by the area of the formed electrode, so that the back electrode with the electrode formed only on the back surface Type solar cells have been developed, and solar cell modules using back electrode type solar cells have also been developed. The solar cell module is obtained by electrically connecting a plurality of solar cells to form a solar cell string, and sealing the solar cell string with a resin or the like.
　図１５は、特許文献１（特開２００５－３４０３６２号公報）に開示されている裏面電極型太陽電池セル（以下、「太陽電池セル」ということもある。）を表わす図である。図１５（ａ）に、特許文献１に開示されている裏面電極型太陽電池セルを裏面側から見た模式的な平面図を示し、図１５（ｂ）に、図１５（ａ）のＧ－Ｇ’に沿った断面を矢印の方向から見た模式的な断面図を示す。図１５（ａ）および図１５（ｂ）に示すように、太陽電池セル１０１のシリコン基板１２１の裏面にはｎ電極１０２およびｐ電極１０３が形成されており、太陽電池セル１０１のシリコン基板１２１の裏面側には櫛形状のｎ+層１０４および櫛形状のｐ+層１０５が形成されている。また、ｎ+層１０４上にはｎ電極１０２が形成され、ｐ+層１０５上にはｐ電極１０３が形成されている。 FIG. 15 is a diagram showing a back electrode type solar cell (hereinafter also referred to as “solar cell”) disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2005-340362). FIG. 15 (a) shows a schematic plan view of the back electrode type solar cell disclosed in Patent Document 1 as seen from the back side, and FIG. 15 (b) shows a G- The typical sectional view which looked at the section along G 'from the direction of the arrow is shown. As shown in FIGS. 15A and 15B, an n electrode 102 and a p electrode 103 are formed on the back surface of the silicon substrate 121 of the solar battery cell 101, and the silicon substrate 121 of the solar battery cell 101 has A comb-shaped n + layer 104 and a comb-shaped p + layer 105 are formed on the back side. An n electrode 102 is formed on the n + layer 104, and a p electrode 103 is formed on the p + layer 105.
　図１６は、特許文献１に開示されている太陽電池セルを接続するための配線基板の模式的な平面図である。ここで、配線基板１０６の絶縁性基板１１６の表面上には、太陽電池セル１０１のｎ電極１０２に接続するためのｎ配線１０７、太陽電池セル１０１のｐ電極１０３に接続するためのｐ配線１０８、およびｎ配線１０７とｐ配線１０８とを電気的に接続するための接続配線１０９が形成されている。 FIG. 16 is a schematic plan view of a wiring board for connecting solar cells disclosed in Patent Document 1. FIG. Here, on the surface of the insulating substrate 116 of the wiring substrate 106, an n wiring 107 for connecting to the n electrode 102 of the solar battery cell 101 and a p wiring 108 for connecting to the p electrode 103 of the solar battery cell 101. In addition, a connection wiring 109 for electrically connecting the n wiring 107 and the p wiring 108 is formed.
　図１７は、配線基板１０６に複数の太陽電池セル１０１が配置された太陽電池ストリング１１０を受光面側から見た模式的な平面図である。なお、図１７では、説明の便宜のため、接続配線１０９の記載を省略している。ここで、太陽電池ストリング１１０においては、配線基板１０６のｎ配線１０７およびｐ配線１０８に、それぞれ、太陽電池セル１０１のｎ電極１０２およびｐ電極１０３が電気的に接続されるように、複数の太陽電池セル１０１が配置されている。 FIG. 17 is a schematic plan view of a solar cell string 110 in which a plurality of solar cells 101 are arranged on the wiring substrate 106 as viewed from the light receiving surface side. In FIG. 17, the connection wiring 109 is not shown for convenience of explanation. Here, in solar cell string 110, a plurality of solar cells are connected such that n electrode 102 and p electrode 103 of solar cell 101 are electrically connected to n wiring 107 and p wiring 108 of wiring substrate 106, respectively. Battery cell 101 is arranged.
特開２００５－３４０３６２号公報JP 2005-340362 A
　図１８は、太陽電池セル１０１を直列に電気的に接続したものを複数列に並べた太陽電池ストリング１１０を受光面側から見た模式的な平面図である。太陽電池ストリング１１０は、配線基板１０６上に太陽電池セル１０１を直列に並べたものを２列並べている。なお、図１８においても、説明の便宜のため、接続配線１０９の記載を省略している。図１９に、図１８のＨ－Ｈ’に沿った断面を矢印の方向から見た模式的な断面図を示す。 FIG. 18 is a schematic plan view of a solar cell string 110 in which solar cells 101 electrically connected in series are arranged in a plurality of rows as viewed from the light receiving surface side. The solar cell string 110 includes two rows of solar cell cells 101 arranged in series on the wiring substrate 106. In FIG. 18, the connection wiring 109 is not shown for convenience of explanation. FIG. 19 is a schematic cross-sectional view of the cross section taken along the line H-H ′ of FIG. 18 as viewed from the direction of the arrow.
　太陽電池セル１０１において、シリコン基板１２１の導電型と同じ導電型の電極は、シリコン基板１２１と同電位となるが、シリコン基板１２１の導電型と異なる導電型の電極は、ｐｎ接合で生じる電位差をシリコン基板１２１との間に有する。たとえば、シリコン基板１２１の導電型がｎ型であるとすると、ｎ電極１０２とシリコン基板１２１とは同電位となるが、ｐ電極１０３とシリコン基板１２１とはｐｎ接合で生じる電位差を有することとなる。 In the solar cell 101, an electrode having the same conductivity type as that of the silicon substrate 121 has the same potential as that of the silicon substrate 121, but an electrode having a conductivity type different from that of the silicon substrate 121 has a potential difference generated at the pn junction. Between the silicon substrate 121. For example, if the conductivity type of the silicon substrate 121 is n-type, the n electrode 102 and the silicon substrate 121 have the same potential, but the p electrode 103 and the silicon substrate 121 have a potential difference generated at the pn junction. .
　したがって、図１９に示すように、隣り合う太陽電池セル１０１の向かい合う端部に最も近い電極がｎ電極１０２およびｐ電極１０３と異なっており、シリコン基板１２１がｎ型である場合には、シリコン基板１２１とｎ電極１０２とは同電位となるが、シリコン基板１２１とｐ電極１０３とは電位差を有することになる。 Accordingly, as shown in FIG. 19, when the electrodes closest to the facing ends of the adjacent solar cells 101 are different from the n-electrode 102 and the p-electrode 103, and the silicon substrate 121 is n-type, the silicon substrate 121 and the n electrode 102 have the same potential, but the silicon substrate 121 and the p electrode 103 have a potential difference.
　その結果、隣り合う太陽電池セル１０１のそれぞれの太陽電池セル１０１の端部において太陽電池セル１０１の厚さ方向の電位分布が異なるため、隣り合う太陽電池セル１０１間に電位分布の偏りが生じる。そして、隣り合う太陽電池セル１０１間の間隔が狭いほどその電位分布の偏りが太陽電池セル１０１の特性に影響を及ぼし、太陽電池ストリング１１０の特性が低下することがあった。 As a result, the potential distribution in the thickness direction of the solar battery cells 101 is different at the end portions of the solar battery cells 101 of the adjacent solar battery cells 101, so that the potential distribution is biased between the adjacent solar battery cells 101. Then, as the interval between adjacent solar cells 101 is narrower, the bias of the potential distribution affects the characteristics of the solar cells 101, and the characteristics of the solar cell string 110 may be deteriorated.
　図２０は、隣り合う太陽電池セル１０１の端部に最も近い電極の導電型がシリコン基板１２１の導電型（この場合には、ｎ型）とは異なる太陽電池ストリングの模式的な拡大断面図である。この場合には、隣り合う太陽電池セル１０１同士で、シリコン基板１２１と電極間の電位差は同じとなるが、それぞれの太陽電池セル１０１の端部において、太陽電池セル１０１の厚さ方向の電位分布により、太陽電池セル１０１とその外側とに電位分布の偏りが生じる。この場合にも、上記と同様に、電位分布の偏りが太陽電池セル１０１の特性に影響を及ぼし、太陽電池ストリング１１０の特性が低下することがあった。 FIG. 20 is a schematic enlarged cross-sectional view of a solar cell string in which the conductivity type of the electrode closest to the end of the adjacent solar cell 101 is different from the conductivity type of the silicon substrate 121 (in this case, n-type). is there. In this case, the potential difference between the silicon substrate 121 and the electrode is the same between adjacent solar cells 101, but the potential distribution in the thickness direction of the solar cells 101 at the end of each solar cell 101. As a result, the potential distribution is biased between the solar battery cell 101 and the outside thereof. Also in this case, similarly to the above, the bias of the potential distribution may affect the characteristics of the solar battery cell 101, and the characteristics of the solar battery string 110 may be deteriorated.
　上記の事情に鑑みて、本発明の目的は、隣り合う太陽電池セルの端部の厚さ方向における電位分布の偏りによる太陽電池ストリングの特性の低下を抑制することが可能な太陽電池ストリングおよび太陽電池モジュールを提供することにある。 In view of the above circumstances, an object of the present invention is to provide a solar cell string and a solar cell capable of suppressing a deterioration in the characteristics of the solar cell string due to a bias in potential distribution in the thickness direction of end portions of adjacent solar cells. The object is to provide a battery module.
　本発明は、第１方向と、第１方向に直交する第２方向と、にそれぞれ複数ずつ配置された裏面電極型太陽電池セルを含み、裏面電極型太陽電池セルは、シリコン基板と、シリコン基板の受光面と反対側の裏面に設けられた第１導電型用電極および第２導電型用電極とを有し、第１導電型用電極は、シリコン基板の裏面の第１方向に沿って配置され、第２導電型用電極は、シリコン基板の裏面の第１方向に沿って第１導電型用電極と間隔を空けて配置されており、第２方向に隣り合う裏面電極型太陽電池セルは、裏面電極型太陽電池セルの端部に最も近い電極同士が同一の導電型であるように配置されている太陽電池ストリングである。 The present invention includes a back electrode type solar battery cell that is arranged in a plurality in each of a first direction and a second direction orthogonal to the first direction. The back electrode type solar battery cell includes a silicon substrate and a silicon substrate. Having a first conductivity type electrode and a second conductivity type electrode provided on the back surface opposite to the light receiving surface, and the first conductivity type electrode is disposed along the first direction of the back surface of the silicon substrate. The second conductivity type electrode is disposed at a distance from the first conductivity type electrode along the first direction of the back surface of the silicon substrate, and the back electrode type solar cells adjacent in the second direction are The solar cell string is arranged such that the electrodes closest to the end portions of the back electrode type solar cells are of the same conductivity type.
　ここで、本発明の太陽電池ストリングにおいて、シリコン基板は第１導電型であり、裏面電極型太陽電池セルの端部に最も近い電極は第１導電型用電極であることが好ましい。 Here, in the solar cell string of the present invention, the silicon substrate is preferably the first conductivity type, and the electrode closest to the end of the back electrode type solar cell is preferably the first conductivity type electrode.
　また、本発明の太陽電池ストリングにおいて、裏面電極型太陽電池セルは、シリコン基板の受光面に受光面不純物半導体層が形成されていることが好ましい。 In the solar cell string of the present invention, it is preferable that the back electrode type solar cell has a light receiving surface impurity semiconductor layer formed on the light receiving surface of the silicon substrate.
　また、本発明の太陽電池ストリングにおいて、裏面電極型太陽電池セルの端部に最も近い前記電極は、受光面不純物半導体層に電気的に接続されていることが好ましい。 In the solar cell string of the present invention, it is preferable that the electrode closest to the end of the back electrode type solar cell is electrically connected to the light-receiving surface impurity semiconductor layer.
　また、本発明の太陽電池ストリングは、配線基材をさらに含み、裏面電極型太陽電池セルは配線基材上に配置されており、配線基材は第１導電型用配線と第２導電型用配線とを有し、第１導電型用電極は第１導電型用配線と電気的に接続され、第２導電型用電極は第２導電型用配線と電気的に接続されていることが好ましい。 Moreover, the solar cell string of the present invention further includes a wiring substrate, the back electrode type solar cell is disposed on the wiring substrate, and the wiring substrate is for the first conductivity type wiring and the second conductivity type. Preferably, the first conductivity type electrode is electrically connected to the first conductivity type wire, and the second conductivity type electrode is electrically connected to the second conductivity type wire. .
　さらに、本発明は、上記のいずれかの太陽電池ストリングと、透明基材と、太陽電池ストリングと透明基材との間の封止材とを含む太陽電池モジュールである。 Furthermore, the present invention is a solar cell module including any one of the above solar cell strings, a transparent base material, and a sealing material between the solar cell string and the transparent base material.
　本発明によれば、隣り合う太陽電池セルの端部の厚さ方向における電位分布の偏りによる太陽電池ストリングの特性の低下を抑制することが可能な太陽電池ストリングおよび太陽電池モジュールを提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the solar cell string and solar cell module which can suppress the fall of the characteristic of a solar cell string by the bias of the electric potential distribution in the thickness direction of the edge part of an adjacent photovoltaic cell are provided. it can.
（ａ）は、実施の形態１の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図であり、（ｂ）は、（ａ）のＡ－Ａ’に沿った断面を矢印の方向から見た模式的な断面図である。(A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 1 from the back surface side, (b) is AA of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow. 実施の形態１の太陽電池ストリングに用いられる配線基材の一例の模式的な平面図である。FIG. 3 is a schematic plan view of an example of a wiring substrate used for the solar cell string in the first embodiment. 実施の形態１の太陽電池ストリングを受光面側から見たときの模式的な平面図である。It is a typical top view when the solar cell string of Embodiment 1 is seen from the light-receiving surface side. 図３のＢ－Ｂ’に沿った断面を矢印の方向から見た模式的な断面図である。FIG. 4 is a schematic cross-sectional view taken along the line B-B ′ of FIG. 3 as viewed from the direction of the arrow. 実施の形態２の太陽電池ストリングを受光面側から見たときの模式的な平面図である。It is a typical top view when the solar cell string of Embodiment 2 is seen from the light-receiving surface side. 図５のＣ－Ｃ’に沿った断面を矢印の方向から見た模式的な断面図である。FIG. 6 is a schematic cross-sectional view taken along the line C-C ′ of FIG. 5 as viewed from the direction of the arrow. （ａ）は、実施の形態３の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図であり、（ｂ）は、（ａ）のＬ－Ｌ’に沿った断面を矢印の方向から見た模式的な断面図である。(A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 3 from the back surface side, (b) is LL of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow. 実施の形態３の太陽電池ストリングを受光面側から見たときの模式的な平面図である。It is a typical top view when the solar cell string of Embodiment 3 is seen from the light-receiving surface side. 図８のＭ－Ｍ’に沿った断面を矢印の方向から見た模式的な断面図である。FIG. 9 is a schematic cross-sectional view taken along the line M-M ′ of FIG. 8 as viewed from the direction of the arrow. （ａ）は、実施の形態４の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図であり、（ｂ）は、（ａ）のＤ－Ｄ’に沿った断面を矢印の方向から見た模式的な断面図である。(A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 4 from the back surface side, (b) is DD of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow. 実施の形態４の太陽電池ストリングに用いられる配線基材の一例の模式的な平面図である。FIG. 10 is a schematic plan view of an example of a wiring substrate used for the solar cell string in the fourth embodiment. 実施の形態４の太陽電池ストリングを受光面側から見たときの模式的な平面図である。It is a typical top view when the solar cell string of Embodiment 4 is seen from the light-receiving surface side. 図１２のＥ－Ｅ’に沿った断面を矢印の方向から見た模式的な断面図である。FIG. 13 is a schematic cross-sectional view taken along the line E-E ′ of FIG. 12 as viewed from the direction of the arrow. （ａ）は、実施の形態５の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図であり、（ｂ）は、（ａ）のＦ－Ｆ’に沿った断面を矢印の方向から見た模式的な断面図である。(A) is the typical top view which looked at an example of the back electrode type photovoltaic cell used for the solar cell string of Embodiment 5 from the back surface side, (b) is FF of (a). It is typical sectional drawing which looked at the cross section along 'from the direction of the arrow. （ａ）は、特許文献１に開示されている裏面電極型太陽電池セルを裏面側から見た模式的な平面図であり、（ｂ）は、（ａ）のＧ－Ｇ’に沿った断面を矢印の方向から見た模式的な断面図である。(A) is the typical top view which looked at the back electrode type photovoltaic cell currently indicated by patent documents 1 from the back side, and (b) is a section along GG 'of (a). It is typical sectional drawing which looked at from the direction of the arrow. 特許文献１に開示されている太陽電池セルを接続するための配線基板の模式的な平面図である。It is a typical top view of the wiring board for connecting the photovoltaic cell currently disclosed by patent document 1. FIG. 配線基板に複数の太陽電池セルが配置された太陽電池ストリングを受光面側から見た模式的な平面図である。It is the typical top view which looked at the photovoltaic cell string by which the several photovoltaic cell was arrange | positioned on the wiring board from the light-receiving surface side. 太陽電池セルを直列に接続したものを複数列に並べた太陽電池ストリングを受光面側から見た模式的な平面図である。It is the typical top view which looked at the solar cell string which arranged what connected the photovoltaic cell in series in multiple rows from the light-receiving surface side. 図１８のＨ－Ｈ’に沿った断面を矢印の方向から見た模式的な断面図である。FIG. 19 is a schematic cross-sectional view taken along the line H-H ′ of FIG. 18 as viewed from the direction of the arrows. 隣り合う太陽電池セルの端部に最も近い電極の導電型がシリコン基板の導電型とは異なる太陽電池ストリングの模式的な拡大断面図である。It is a typical expanded sectional view of the solar cell string from which the conductivity type of the electrode nearest to the edge part of an adjacent photovoltaic cell differs from the conductivity type of a silicon substrate.
　以下、本発明の実施の形態について説明する。なお、本発明の図面において、同一の参照符号は、同一部分または相当部分を表わすものとする。 Hereinafter, embodiments of the present invention will be described. In the drawings of the present invention, the same reference numerals represent the same or corresponding parts.
　＜実施の形態１＞
　図１（ａ）に、実施の形態１の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図を示し、図１（ｂ）に、図１（ａ）のＡ－Ａ’に沿った断面を矢印の方向から見た模式的な断面図を示す。 <Embodiment 1>
FIG. 1A shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar cell string of the first embodiment as viewed from the back side, and FIG. FIG. 3A is a schematic cross-sectional view of a cross section taken along line AA ′ in a) when viewed from the direction of an arrow.
　図１（ａ）に示すように、裏面電極型太陽電池セル１のｎ型シリコン基板２１の受光面と反対側の裏面には、ドット状のｎ型用電極２の複数が、第１方向（ｎ型シリコン基板２１の１辺方向）および第２方向（ｎ型シリコン基板２１の他の１辺方向）のそれぞれの方向にライン状に配列されてｎ型用電極２の列を形成している。また、ドット状のｐ型用電極３の複数が、ｎ型用電極２の列と所定の間隔を空けて、第１方向および第２方向のそれぞれの方向にライン状に配列されてｐ型用電極３の列を形成している。 As shown in FIG. 1 (a), a plurality of dot-shaped electrodes 2 for n-type are formed in the first direction (on the back surface opposite to the light receiving surface of the n-type silicon substrate 21 of the back-electrode solar cell 1 in the first direction ( A row of n-type electrodes 2 is formed by being arranged in a line in each direction of the n-type silicon substrate 21 (one side direction) and the second direction (the other one-side direction of the n-type silicon substrate 21). . In addition, a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type. A row of electrodes 3 is formed.
　また、ｎ型用電極２の列とｐ型用電極３の列とは、それぞれ交互に１本ずつ配置されている。ここで、裏面電極型太陽電池セル１のｎ型シリコン基板２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されている電極は、ｎ型用電極２である。 Further, the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one. Here, on the back surface of the n-type silicon substrate 21 of the back electrode type solar cell 1, the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. It is.
　なお、本実施の形態において、第１方向と第２方向とが直交している場合について説明するが、第１方向と第２方向とが為す角度は実質的に９０°であればよい。 In the present embodiment, the case where the first direction and the second direction are orthogonal to each other will be described. However, the angle formed by the first direction and the second direction may be substantially 90 °.
　また、図１（ｂ）に示すように、ｎ型シリコン基板２１の裏面にｎ型半導体領域４およびｐ型半導体領域５が形成されており、ｎ型半導体領域４上にｎ型用電極２が形成され、ｐ型半導体領域５上にｐ型用電極３が形成されている。ｎ型半導体領域４およびｐ型半導体領域５は、それぞれ、ｎ型用電極２の列およびｐ型用電極３の列に沿ったライン状に形成されている。なお、ｎ型シリコン基板２１の受光面は、入射光が入射する側の面であり、ｎ型シリコン基板２１の裏面は、受光面と反対側の面である。 Further, as shown in FIG. 1B, an n-type semiconductor region 4 and a p-type semiconductor region 5 are formed on the back surface of the n-type silicon substrate 21, and an n-type electrode 2 is formed on the n-type semiconductor region 4. The p-type electrode 3 is formed on the p-type semiconductor region 5. The n-type semiconductor region 4 and the p-type semiconductor region 5 are formed in a line shape along the column of the n-type electrode 2 and the column of the p-type electrode 3, respectively. The light receiving surface of the n-type silicon substrate 21 is a surface on the side where incident light is incident, and the back surface of the n-type silicon substrate 21 is a surface opposite to the light receiving surface.
　図１（ａ）および図１（ｂ）に示す裏面電極型太陽電池セル１の第２方向においてｎ型シリコン基板２１の裏面の端部に形成されている電極はｎ型用電極２である。また、ｎ型半導体領域４およびｐ型半導体領域５は、必ずしも交互に形成されている必要はない。また、ｎ型用電極２およびｐ型用電極３は、ｎ型用電極２の列およびｐ型用電極３の列ごとにそれぞれ一体化したライン状に形成されていてもよい。 The electrode formed at the end portion of the back surface of the n-type silicon substrate 21 in the second direction of the back-surface electrode type solar cell 1 shown in FIGS. 1A and 1B is an n-type electrode 2. Further, the n-type semiconductor regions 4 and the p-type semiconductor regions 5 do not necessarily have to be formed alternately. Further, the n-type electrode 2 and the p-type electrode 3 may be formed in an integrated line shape for each row of the n-type electrode 2 and each row of the p-type electrode 3.
　図２に、実施の形態１の太陽電池ストリングに用いられる配線基材の一例の模式的な平面図を示す。ここで、配線基材６は、絶縁性基材１６と、絶縁性基材１６の表面上に設けられたｎ配線７、ｐ配線８、およびｎ配線７とｐ配線８とを電気的に接続するための接続配線９を有している。なお、絶縁性基材１６は、たとえばシート状または基板状などの形状を有する絶縁体である。 FIG. 2 shows a schematic plan view of an example of a wiring substrate used in the solar cell string of the first embodiment. Here, the wiring substrate 6 electrically connects the insulating substrate 16, the n wiring 7 and the p wiring 8 provided on the surface of the insulating substrate 16, and the n wiring 7 and the p wiring 8. Connection wiring 9 is provided. The insulating base 16 is an insulator having a shape such as a sheet shape or a substrate shape.
　また、配線基材６の絶縁性基材１６の表面上において、ｎ配線７およびｐ配線８は、それぞれ、ライン状に形成されている。また、ｎ配線７およびｐ配線８は、それぞれ、第２方向に１本ずつ交互に所定の間隔を空けて配列されている。また、接続配線９は、第２方向に伸長する矩形状に形成されている。接続配線９は、第２方向に配列されたｎ配線７のそれぞれの一端および／または第２方向に配列されたｐ配線８のそれぞれの一端と電気的に接続されている。 Further, the n wiring 7 and the p wiring 8 are each formed in a line shape on the surface of the insulating base material 16 of the wiring base material 6. Further, the n wiring 7 and the p wiring 8 are arranged one by one in the second direction alternately at a predetermined interval. The connection wiring 9 is formed in a rectangular shape extending in the second direction. The connection wiring 9 is electrically connected to one end of each n wiring 7 arranged in the second direction and / or one end of each p wiring 8 arranged in the second direction.
　図３に、実施の形態１の太陽電池ストリングを受光面側から見たときの模式的な平面図を示す。ここで、太陽電池ストリング１０は、配線基材６と、配線基材６上に配置された裏面電極型太陽電池セル１とを備えており、裏面電極型太陽電池セル１は、配線基材６上において、第１方向および第２方向にそれぞれ配列されている。また、裏面電極型太陽電池セル１は、それぞれ、第１方向に、直列に接続されている。そして、この裏面電極型太陽電池セル１の第１方向に直列に接続された２列が、第２方向に所定の間隔を空けて平行に設置されている。なお、図３では、説明の便宜のため、接続配線９の記載が省略されている。 FIG. 3 shows a schematic plan view of the solar cell string of the first embodiment when viewed from the light receiving surface side. Here, the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively. The back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction. In FIG. 3, the connection wiring 9 is not shown for convenience of explanation.
　図４に、図３のＢ－Ｂ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、太陽電池ストリング１０は、裏面電極型太陽電池セル１のｎ型用電極２が配線基材６のｎ配線７と電気的に接続されており、裏面電極型太陽電池セル１のｐ型用電極３が配線基材６のｐ配線８と電気的に接続されている。 FIG. 4 shows a schematic cross-sectional view of the cross-section along B-B ′ of FIG. 3 as seen from the direction of the arrow. Here, in the solar cell string 10, the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1. The electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
　実施の形態１において、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部に最も近い電極は、ともに同一の導電型用の電極であるｎ型用電極２である。裏面電極型太陽電池セル１の第２方向の端部のｎ型用電極２は、ｎ型シリコン基板２１と同一の導電型用（この場合には、ｎ型用）の電極となっているため、ｎ型シリコン基板２１とは同電位となり、裏面電極型太陽電池セル１の端部において、裏面電極型太陽電池セル１の厚さ方向に電位分布を生じさせない。そのため、第２方向において隣り合う裏面電極型太陽電池セル１間に生じる電位分布は、裏面電極型太陽電池セル１の厚さ方向に変化せず、電位分布の偏りが生じない。これにより、実施の形態１においては、隣り合う裏面電極型太陽電池セル１の端部の厚さ方向における電位分布の偏りによる特性の低下を抑制することができるため、太陽電池ストリング１０の特性の低下を抑制することができる。 In Embodiment 1, the electrodes closest to the facing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 which are electrodes of the same conductivity type. The n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for the same conductivity type as the n-type silicon substrate 21 (in this case, for n-type). The potential is the same as that of the n-type silicon substrate 21, and no potential distribution is generated in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1. Therefore, the potential distribution generated between the back electrode type solar cells 1 adjacent in the second direction does not change in the thickness direction of the back electrode type solar cell 1, and the potential distribution is not biased. Thereby, in Embodiment 1, since the fall of the characteristic by the bias of the electric potential distribution in the thickness direction of the edge part of the adjacent back electrode type photovoltaic cell 1 can be suppressed, the characteristic of the solar cell string 10 is suppressed. The decrease can be suppressed.
　＜実施の形態２＞
　図５に、実施の形態２の太陽電池ストリングを受光面側から見たときの模式的な平面図を示す。ここで、実施の形態２の太陽電池ストリング１０においては、配線基材６上において、裏面電極型太陽電池セル１が、第１方向および第２方向にそれぞれ３つずつ配置されている点に特徴がある。また、裏面電極型太陽電池セル１は、それぞれ、第１方向に沿って、直列に接続されており、裏面電極型太陽電池セル１の直列に接続された列の３つが第２方向に所定の間隔を空けて平行に設置されている。なお、図５では、説明の便宜のため、接続配線９の記載が省略されている。 <Embodiment 2>
In FIG. 5, the typical top view when the solar cell string of Embodiment 2 is seen from the light-receiving surface side is shown. Here, the solar cell string 10 of the second embodiment is characterized in that three back electrode type solar cells 1 are arranged on the wiring base 6 in the first direction and in the second direction, respectively. There is. The back electrode type solar cells 1 are connected in series along the first direction, and three of the back electrode type solar cells 1 connected in series are predetermined in the second direction. It is installed in parallel with a gap. In FIG. 5, the connection wiring 9 is not shown for convenience of explanation.
　図６に、図５のＣ－Ｃ’に沿った断面を矢印の方向から見た模式的な断面図を示す。実施の形態２においては、第２方向、において裏面電極型太陽電池セル１の隣り合う箇所が２箇所存在する。第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部に最も近い電極は、ともに同一の導電型用の電極であるｎ型用電極２である。裏面電極型太陽電池セル１の第２方向の端部のｎ型用電極２は、ｎ型シリコン基板２１と同一の導電型（この場合には、ｎ型）用の電極となっているため、ｎ型シリコン基板２１とは同電位となり、裏面電極型太陽電池セル１の端部において、裏面電極型太陽電池セル１の厚さ方向に電位分布を生じない。そのため、実施の形態２においても、隣り合う裏面電極型太陽電池セル１の端部の厚さ方向における電位分布の偏りによる特性の低下を抑制することができるため、太陽電池ストリング１０の特性の低下を抑制することができる。 FIG. 6 shows a schematic cross-sectional view of the cross-section along C-C ′ of FIG. 5 as seen from the direction of the arrow. In the second embodiment, there are two adjacent portions of the back electrode type solar cell 1 in the second direction. The electrodes closest to the opposing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type. Since the n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for the same conductivity type (in this case, n-type) as the n-type silicon substrate 21, The potential is the same as that of the n-type silicon substrate 21, and no potential distribution is generated in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1. For this reason, also in the second embodiment, since it is possible to suppress the deterioration of the characteristics due to the bias of the potential distribution in the thickness direction of the end portions of the adjacent back electrode type solar cells 1, the characteristics of the solar cell string 10 are deteriorated. Can be suppressed.
　また、実施の形態１および実施の形態２においては、ｎ型シリコン基板を用いた場合について説明したが、ｐ型シリコン基板を用いることもできる。ｐ型シリコン基板を用いた場合には、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部において裏面電極型太陽電池セル１の端部に最も近い電極は、ともに同一の導電型用の電極であるｐ型用電極３となる。他の構造は、ｎ型シリコン基板を用いた場合と同様である。また、配線基材６も、ｐ型シリコン基板を用いた場合に形成される電極の形状に合わせた配線が配置された構造を有することは言うまでもない。 In the first and second embodiments, the case where an n-type silicon substrate is used has been described. However, a p-type silicon substrate can also be used. When a p-type silicon substrate is used, the electrodes closest to the end portion of the back electrode type solar cell 1 at the opposite end portions of the back electrode type solar cells 1 adjacent in the second direction are both the same. It becomes the electrode 3 for p-types which is an electrode for conductivity types. The other structure is the same as that when an n-type silicon substrate is used. Needless to say, the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when a p-type silicon substrate is used.
　＜実施の形態３＞
　図７（ａ）に、実施の形態３の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図を示し、図７（ｂ）に、図７（ａ）のＬ－Ｌ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、実施の形態３においては、裏面電極型太陽電池セル１のｎ型シリコン基板２１の受光面に受光面不純物半導体層であるｎ型半導体領域１３が形成されている点に特徴がある。 <Embodiment 3>
FIG. 7A shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar cell string of Embodiment 3, as viewed from the back side, and FIG. FIG. 3A is a schematic cross-sectional view of a cross section taken along line LL ′ of a) when viewed from the direction of an arrow. Here, the third embodiment is characterized in that an n-type semiconductor region 13 that is a light-receiving surface impurity semiconductor layer is formed on the light-receiving surface of the n-type silicon substrate 21 of the back electrode type solar cell 1.
　図７（ａ）に示すように、裏面電極型太陽電池セル１のｎ型シリコン基板２１の受光面と反対側の裏面には、ドット状のｎ型用電極２の複数が、第１方向（ｎ型シリコン基板２１の１辺方向）および第２方向（ｎ型シリコン基板２１の他の１辺方向）のそれぞれの方向にライン状に配列されてｎ型用電極２の列を形成している。また、ドット状のｐ型用電極３の複数が、ｎ型用電極２の列と所定の間隔を空けて、第１方向および第２方向のそれぞれの方向にライン状に配列されてｐ型用電極３の列を形成している。 As shown in FIG. 7 (a), a plurality of dot-shaped electrodes 2 are arranged in the first direction (on the back surface opposite to the light receiving surface of the n-type silicon substrate 21 of the back-electrode solar cell 1 in the first direction ( A row of n-type electrodes 2 is formed by being arranged in a line in each direction of the n-type silicon substrate 21 (one side direction) and the second direction (the other one-side direction of the n-type silicon substrate 21). . In addition, a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type. A row of electrodes 3 is formed.
　また、ｎ型用電極２の列とｐ型用電極３の列とは、それぞれ交互に１本ずつ配置されている。ここで、裏面電極型太陽電池セル１のｎ型シリコン基板２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されている電極はｎ型用電極２である。 Further, the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one. Here, on the back surface of the n-type silicon substrate 21 of the back electrode type solar cell 1, the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
　なお、本実施の形態において、第１方向と第２方向とが直交している場合について説明するが、第１方向と第２方向とが為す角度は実質的に９０°であればよい。 In the present embodiment, the case where the first direction and the second direction are orthogonal to each other will be described. However, the angle formed by the first direction and the second direction may be substantially 90 °.
　また、図７（ｂ）に示すように、裏面電極型太陽電池セル１のｎ型シリコン基板２１の受光面には受光面不純物半導体層としてのｎ型半導体領域１３であるＦＳＦ（Front　Surface　Field）層が形成されている。ここで、ｎ型半導体領域４およびｎ型半導体領域１３は、それぞれ、ｎ型シリコン基板２１よりもｎ型不純物濃度が高い。 Further, as shown in FIG. 7B, the light receiving surface of the n-type silicon substrate 21 of the back electrode type solar cell 1 has an FSF (Front Surface Field) which is an n-type semiconductor region 13 as a light-receiving surface impurity semiconductor layer. A layer is formed. Here, each of the n-type semiconductor region 4 and the n-type semiconductor region 13 has an n-type impurity concentration higher than that of the n-type silicon substrate 21.
　裏面電極型太陽電池セル１のｎ型シリコン基板２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されている電極はｎ型用電極２である。また、ｎ型用電極２の列とｐ型用電極３の列とは、１本ずつ交互に配置されている。また、ドット状のｐ型用電極３の複数がｎ型用電極２の配列と所定の間隔を空けて第１方向および第２方向のそれぞれの方向にライン状に配列されてｐ型用電極３の列を形成している。 The electrode arranged on the outermost side in the second direction among the electrodes arranged in a line on the back surface of the n-type silicon substrate 21 of the back electrode type solar cell 1 is the n-type electrode 2. Further, the columns of the n-type electrodes 2 and the columns of the p-type electrodes 3 are alternately arranged one by one. In addition, a plurality of dot-type p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at predetermined intervals from the arrangement of the n-type electrodes 2, and the p-type electrode 3. Form a column.
　また、図７（ｂ）に示すように、ｎ型シリコン基板２１の裏面にｎ型半導体領域４およびｐ型半導体領域５が形成されており、ｎ型半導体領域４上にｎ型用電極２が形成され、ｐ型半導体領域５上にｐ型用電極３が形成されている。ｎ型半導体領域４およびｐ型半導体領域５は、それぞれ、ｎ型用電極２の列およびｐ型用電極３の列に沿ったライン状に形成されている。なお、ｎ型シリコン基板２１の受光面は、入射光が入射する側の面であり、ｎ型シリコン基板２１の裏面は、受光面と反対側の面である。 Further, as shown in FIG. 7B, the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the n-type silicon substrate 21, and the n-type electrode 2 is formed on the n-type semiconductor region 4. The p-type electrode 3 is formed on the p-type semiconductor region 5. The n-type semiconductor region 4 and the p-type semiconductor region 5 are formed in a line shape along the column of the n-type electrode 2 and the column of the p-type electrode 3, respectively. The light receiving surface of the n-type silicon substrate 21 is a surface on the side where incident light is incident, and the back surface of the n-type silicon substrate 21 is a surface opposite to the light receiving surface.
　図７（ａ）および図７（ｂ）に示す裏面電極型太陽電池セル１の第２方向においてｎ型シリコン基板２１の裏面の端部に形成されている電極はｎ型用電極２である。また、ｎ型半導体領域４およびｐ型半導体領域５は、必ずしも交互に形成されている必要はない。また、ｎ型用電極２およびｐ型用電極３は、ｎ型用電極２の列およびｐ型用電極３の列ごとにそれぞれ一体化したライン状に形成されていてもよい。 The electrode formed at the end of the back surface of the n-type silicon substrate 21 in the second direction of the back-surface electrode type solar cell 1 shown in FIGS. 7A and 7B is the n-type electrode 2. Further, the n-type semiconductor regions 4 and the p-type semiconductor regions 5 do not necessarily have to be formed alternately. Further, the n-type electrode 2 and the p-type electrode 3 may be formed in an integrated line shape for each row of the n-type electrode 2 and each row of the p-type electrode 3.
　図８に、実施の形態３の太陽電池ストリングを受光面側から見たときの模式的な平面図を示す。ここで、太陽電池ストリング１０は、配線基材６と、配線基材６上に配置された裏面電極型太陽電池セル１とを備えており、裏面電極型太陽電池セル１は、配線基材６上において、第１方向および第２方向にそれぞれ配列されている。また、裏面電極型太陽電池セル１は、それぞれ、第１方向に、直列に接続されている。そして、この裏面電極型太陽電池セル１の第１方向に直列に接続された２列が、第２方向に所定の間隔を空けて平行に設置されている。なお、図８では、説明の便宜のため、接続配線９の記載が省略されている。 FIG. 8 shows a schematic plan view of the solar cell string of the third embodiment when viewed from the light receiving surface side. Here, the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively. The back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction. In FIG. 8, the connection wiring 9 is not shown for convenience of explanation.
　図９に、図８のＭ－Ｍ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、太陽電池ストリング１０は、裏面電極型太陽電池セル１のｎ型用電極２が配線基材６のｎ配線７と電気的に接続されており、裏面電極型太陽電池セル１のｐ型用電極３が配線基材６のｐ配線８と電気的に接続されている。 FIG. 9 is a schematic cross-sectional view of the cross section taken along the line M-M ′ of FIG. 8 as seen from the direction of the arrow. Here, in the solar cell string 10, the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1. The electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
　実施の形態３において、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部に最も近い電極は、ともに同一の導電型用の電極であるｎ型用電極２である。裏面電極型太陽電池セル１の第２方向の端部のｎ型用電極２は、ｎ型シリコン基板２１の受光面のｎ型半導体領域１３と同電位となり、裏面電極型太陽電池セル１の端部において、裏面電極型太陽電池セル１の厚さ方向に電位分布を生じさせない。そのため、第２方向において隣り合う裏面電極型太陽電池セル１間に生じる電位分布は、裏面電極型太陽電池セル１の厚さ方向に変化せず、電位分布の偏りが生じない。これにより、実施の形態３においては、隣り合う裏面電極型太陽電池セル１の端部の厚さ方向における電位分布の偏りによる特性の低下を抑制することができるため、太陽電池ストリング１０の特性の低下を抑制することができる。 In Embodiment 3, the electrodes closest to the opposing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type. The n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 has the same potential as the n type semiconductor region 13 on the light receiving surface of the n type silicon substrate 21, and the end of the back electrode type solar cell 1. In the portion, no potential distribution is generated in the thickness direction of the back electrode type solar cell 1. Therefore, the potential distribution generated between the back electrode type solar cells 1 adjacent in the second direction does not change in the thickness direction of the back electrode type solar cell 1, and the potential distribution is not biased. Thereby, in Embodiment 3, since the fall of the characteristic by the bias of the electric potential distribution in the thickness direction of the edge part of the adjacent back electrode type solar cell 1 can be suppressed, the characteristic of the solar cell string 10 is suppressed. The decrease can be suppressed.
　なお、実施の形態３においては、ｎ型シリコン基板を用いた場合について説明したが、ｐ型シリコン基板を用いることもできる。ｐ型シリコン基板を用いた場合には、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部において裏面電極型太陽電池セル１の端部に最も近い電極は、ともに同一の導電型用の電極であるｐ型用電極３となり、ｐ型シリコン基板の受光面にはｐ型シリコン基板よりも不純物濃度が高いｐ型半導体領域を形成する。他の構造は、ｎ型シリコン基板を用いた場合と同様である。また、配線基材６も、ｐ型シリコン基板を用いた場合に形成される電極の形状に合わせた配線が配置された構造を有することは言うまでもない。 In the third embodiment, the case where an n-type silicon substrate is used has been described. However, a p-type silicon substrate can also be used. When a p-type silicon substrate is used, the electrodes closest to the end portion of the back electrode type solar cell 1 at the opposite end portions of the back electrode type solar cells 1 adjacent in the second direction are both the same. A p-type electrode 3 which is an electrode for conductivity type is formed, and a p-type semiconductor region having an impurity concentration higher than that of the p-type silicon substrate is formed on the light receiving surface of the p-type silicon substrate. The other structure is the same as that when an n-type silicon substrate is used. Needless to say, the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when a p-type silicon substrate is used.
　また、実施の形態１～３において、ｎ型シリコン基板を用いて第２方向の最も外側に配置されている電極がｎ型用電極である裏面電極型太陽電池セルと、ｐ型シリコン基板を用いて第２方向の最も外側に配置されている電極がｐ型用電極である裏面電極型太陽電池セルとが、第２方向において、隣り合っていてもよい。 In the first to third embodiments, a back electrode type solar cell in which the electrode arranged on the outermost side in the second direction using an n-type silicon substrate is an n-type electrode, and a p-type silicon substrate are used. Thus, the back electrode type solar cell in which the electrode arranged on the outermost side in the second direction is a p-type electrode may be adjacent in the second direction.
　＜実施の形態４＞
　図１０（ａ）に、実施の形態４の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図を示し、図１０（ｂ）に、図１０（ａ）のＤ－Ｄ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、実施の形態４においては、裏面電極型太陽電池セル１が、ＥＷＴ（Emitter　Wrap　Through）型の裏面電極型太陽電池セルである点に特徴がある。 <Embodiment 4>
FIG. 10 (a) shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar battery string of Embodiment 4 as seen from the back side, and FIG. 10 (b) shows a plan view of FIG. FIG. 3A is a schematic cross-sectional view of a cross-section along DD ′ in a) when viewed from the direction of an arrow. Here, the fourth embodiment is characterized in that the back electrode type solar cell 1 is an EWT (Emitter Wrap Through) type back electrode type solar cell.
　ＥＷＴ型の裏面電極型太陽電池セル１のｐ型シリコン基板５２１の受光面と反対側の裏面には、ドット状のｎ型用電極２の複数が、第１方向（ｐ型シリコン基板５２１の１辺方向）および第２方向（ｐ型シリコン基板５２１の他の１辺方向）のそれぞれの方向にライン状に配列されてｎ型用電極２の列を形成している。また、ドット状のｐ型用電極３の複数が、ｎ型用電極２の列と所定の間隔を空けて、第１方向および第２方向のそれぞれの方向にライン状に配列されてｐ型用電極３の列を形成している。 On the back surface opposite to the light receiving surface of the p-type silicon substrate 521 of the EWT-type back electrode solar cell 1, a plurality of dot-like electrodes 2 for n-type are arranged in the first direction (one of the p-type silicon substrate 521. A row of n-type electrodes 2 is formed by being arranged in a line in the respective directions of the side direction) and the second direction (the other one side direction of the p-type silicon substrate 521). In addition, a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type. A row of electrodes 3 is formed.
　また、ｎ型用電極２の列とｐ型用電極３の列とは、それぞれ交互に１本ずつ配置されている。ここで、裏面電極型太陽電池セル１のｐ型シリコン基板５２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されている電極はｎ型用電極２である。 Further, the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one. Here, on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
　なお、本実施の形態において、第１方向と第２方向とが直交している場合について説明するが、第１方向と第２方向とが為す角度は実質的に９０°であればよい。 In the present embodiment, the case where the first direction and the second direction are orthogonal to each other will be described. However, the angle formed by the first direction and the second direction may be substantially 90 °.
　また、図１０（ｂ）に示すように、ｐ型シリコン基板５２１の裏面にｎ型半導体領域４およびｐ型半導体領域５が形成されており、ｎ型半導体領域４上にｎ型用電極２が形成され、ｐ型半導体領域５上にｐ型用電極３が形成されている。ここで、ｎ型半導体領域４は、ｐ型シリコン基板５２１の裏面から、ｐ型シリコン基板５２１の一部の内部を貫通して、ｐ型シリコン基板５２１の受光面全体に広がっている。すなわち、裏面電極型太陽電池セル１のｐ型シリコン基板５２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されているｎ型用電極２は、ｐ型シリコン基板５２１の受光面のｎ型半導体領域４に電気的に接続されている。 10B, the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the p-type silicon substrate 521, and the n-type electrode 2 is formed on the n-type semiconductor region 4. The p-type electrode 3 is formed on the p-type semiconductor region 5. Here, the n-type semiconductor region 4 extends from the back surface of the p-type silicon substrate 521 through a part of the p-type silicon substrate 521 to the entire light receiving surface of the p-type silicon substrate 521. That is, among the electrodes arranged in a line on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the n-type electrode 2 arranged on the outermost side in the second direction is p-type. The silicon substrate 521 is electrically connected to the n-type semiconductor region 4 on the light receiving surface.
　図１１に、実施の形態４の太陽電池ストリングに用いられる配線基材の一例の模式的な平面図を示す。ここで、配線基材６は、絶縁性基材１６と、絶縁性基材１６の表面上に設けられたｎ配線７、ｐ配線８、およびｎ配線７とｐ配線８とを電気的に接続するための接続配線９を有している。なお、絶縁性基材１６は、たとえばシート状または基板状などの形状を有する絶縁体である。 FIG. 11 shows a schematic plan view of an example of a wiring substrate used in the solar cell string of the fourth embodiment. Here, the wiring substrate 6 electrically connects the insulating substrate 16, the n wiring 7 and the p wiring 8 provided on the surface of the insulating substrate 16, and the n wiring 7 and the p wiring 8. Connection wiring 9 is provided. The insulating base 16 is an insulator having a shape such as a sheet shape or a substrate shape.
　また、配線基材６の絶縁性基材１６の表面上において、ｎ配線７およびｐ配線８は、それぞれ、ライン状に形成されている。また、ｎ配線７およびｐ配線８は、それぞれ、第２方向に１本ずつ交互に所定の間隔を空けて配列されている。また、接続配線９は、第２方向に伸長する矩形状に形成されている。接続配線９は、第２方向に配列されたｎ配線７のそれぞれの一端および／または第２方向に配列されたｐ配線８のそれぞれの一端と電気的に接続されている。 Further, the n wiring 7 and the p wiring 8 are each formed in a line shape on the surface of the insulating base material 16 of the wiring base material 6. Further, the n wiring 7 and the p wiring 8 are arranged one by one in the second direction alternately at a predetermined interval. The connection wiring 9 is formed in a rectangular shape extending in the second direction. The connection wiring 9 is electrically connected to one end of each n wiring 7 arranged in the second direction and / or one end of each p wiring 8 arranged in the second direction.
　図１２に、実施の形態４の太陽電池ストリングを受光面側から見たときの模式的な平面図を示す。ここで、太陽電池ストリング１０は、配線基材６と、配線基材６上に配置された裏面電極型太陽電池セル１とを備えており、裏面電極型太陽電池セル１は、配線基材６上において、第１方向および第２方向にそれぞれ配列されている。また、裏面電極型太陽電池セル１は、それぞれ、第１方向に、直列に接続されている。そして、この裏面電極型太陽電池セル１の第１方向に直列に接続された２列が、第２方向に所定の間隔を空けて平行に設置されている。なお、図１２では、説明の便宜のため、接続配線９の記載が省略されている。 FIG. 12 shows a schematic plan view of the solar cell string of the fourth embodiment when viewed from the light receiving surface side. Here, the solar cell string 10 includes a wiring substrate 6 and a back electrode type solar cell 1 disposed on the wiring substrate 6, and the back electrode type solar cell 1 includes the wiring substrate 6. Above, they are arranged in a first direction and a second direction, respectively. The back electrode type solar cells 1 are connected in series in the first direction. And two rows connected in series in the 1st direction of this back electrode type photovoltaic cell 1 are installed in parallel at predetermined intervals in the 2nd direction. In FIG. 12, the connection wiring 9 is not shown for convenience of explanation.
　図１３に、図１２のＥ－Ｅ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、太陽電池ストリング１０は、裏面電極型太陽電池セル１のｎ型用電極２が配線基材６のｎ配線７と電気的に接続されており、裏面電極型太陽電池セル１のｐ型用電極３が配線基材６のｐ配線８と電気的に接続されている。 FIG. 13 is a schematic cross-sectional view of the cross section taken along the line E-E ′ of FIG. 12 as seen from the direction of the arrow. Here, in the solar cell string 10, the n-type electrode 2 of the back electrode type solar cell 1 is electrically connected to the n wiring 7 of the wiring substrate 6, and the p type of the back electrode type solar cell 1. The electrode 3 is electrically connected to the p wiring 8 of the wiring substrate 6.
　実施の形態４において、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部に最も近い電極は、ともに同一の導電型用の電極であるｎ型用電極２である。裏面電極型太陽電池セル１の第２方向の端部のｎ型用電極２は、ｐ型シリコン基板５２１とは異なる導電型用（この場合には、ｐ型用）の電極であるが、ｐ型シリコン基板５２１の受光面のｎ型半導体領域４とは同電位となり、裏面電極型太陽電池セル１の端部の裏面電極型太陽電池セル１の厚さ方向の電位分布が対称となっている。そのため、第２方向において隣り合う裏面電極型太陽電池セル１の端部間に生じる電位分布は、境界領域となる裏面電極型太陽電池セル１の端部において電位分布が対称となるため、裏面電極型太陽電池セル１の厚さ方向に変化せず、電位分布の偏りが生じない。よって、裏面電極型太陽電池セル１とその外側との電位分布の偏りを抑制することができる。したがって、裏面電極型太陽電池セル１に起因した太陽電池ストリング１０の特性の低下を抑制することができる。 In the fourth embodiment, the electrodes closest to the facing ends of the back electrode type solar cells 1 adjacent in the second direction are both n-type electrodes 2 that are electrodes of the same conductivity type. The n-type electrode 2 at the end in the second direction of the back electrode type solar cell 1 is an electrode for a conductivity type different from the p-type silicon substrate 521 (in this case, for p-type). And the n-type semiconductor region 4 on the light receiving surface of the silicon substrate 521 have the same potential, and the potential distribution in the thickness direction of the back electrode type solar cell 1 at the end of the back electrode type solar cell 1 is symmetric. . Therefore, the potential distribution generated between the end portions of the back electrode type solar cells 1 adjacent in the second direction is symmetrical at the end portions of the back electrode type solar cells 1 serving as the boundary region. The solar cell 1 does not change in the thickness direction, and the potential distribution is not biased. Therefore, the bias of the potential distribution between the back electrode type solar cell 1 and the outside thereof can be suppressed. Accordingly, it is possible to suppress the deterioration of the characteristics of the solar cell string 10 caused by the back electrode type solar cell 1.
　＜実施の形態５＞
　図１４（ａ）に、実施の形態５の太陽電池ストリングに用いられる裏面電極型太陽電池セルの一例を裏面側から見た模式的な平面図を示し、図１４（ｂ）に、図１４（ａ）のＦ－Ｆ’に沿った断面を矢印の方向から見た模式的な断面図を示す。ここで、実施の形態５においては、裏面電極型太陽電池セル１が、ＭＷＴ（Metal　Wrap　Through）型の裏面電極型太陽電池セルである点に特徴がある。 <Embodiment 5>
FIG. 14 (a) shows a schematic plan view of an example of a back electrode type solar battery cell used in the solar battery string of Embodiment 5 as seen from the back side, and FIG. 14 (b) shows FIG. FIG. 3A is a schematic cross-sectional view of a cross section taken along the line FF ′ of a) when viewed from the direction of an arrow. Here, the fifth embodiment is characterized in that the back electrode type solar cell 1 is an MWT (Metal Wrap Through) type back electrode type solar cell.
　ＭＷＴ型の裏面電極型太陽電池セル１のｐ型シリコン基板５２１の受光面と反対側の裏面には、ドット状のｎ型用電極２の複数が、第１方向（ｐ型シリコン基板５２１の１辺方向）および第２方向（ｐ型シリコン基板５２１の他の１辺方向）のそれぞれの方向にライン状に配列されてｎ型用電極２の列を形成している。また、ドット状のｐ型用電極３の複数が、ｎ型用電極２の列と所定の間隔を空けて、第１方向および第２方向のそれぞれの方向にライン状に配列されてｐ型用電極３の列を形成している。 On the back surface opposite to the light receiving surface of the p-type silicon substrate 521 of the MWT back-side electrode type solar battery cell 1, a plurality of dot-like electrodes 2 for n-type are arranged in the first direction (one of the p-type silicon substrate 521 A row of n-type electrodes 2 is formed by being arranged in a line in the respective directions of the side direction) and the second direction (the other one side direction of the p-type silicon substrate 521). In addition, a plurality of dot-shaped p-type electrodes 3 are arranged in a line in each of the first direction and the second direction at a predetermined interval from the row of n-type electrodes 2 and are used for p-type. A row of electrodes 3 is formed.
　また、ｎ型用電極２の列とｐ型用電極３の列とは、それぞれ交互に１本ずつ配置されている。ここで、裏面電極型太陽電池セル１のｐ型シリコン基板５２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されている電極はｎ型用電極２である。 Further, the n-type electrode 2 rows and the p-type electrode 3 rows are alternately arranged one by one. Here, on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the electrode arranged on the outermost side in the second direction among the electrodes arranged in a line is the n-type electrode 2. is there.
　なお、本実施の形態において、第１方向と第２方向とが直交している場合について説明するが、第１方向と第２方向とが為す角度は実質的に９０°であればよい。 In the present embodiment, the case where the first direction and the second direction are orthogonal to each other will be described. However, the angle formed by the first direction and the second direction may be substantially 90 °.
　また、図１４（ｂ）に示すように、ｐ型シリコン基板５２１の裏面にｎ型半導体領域４およびｐ型半導体領域５が形成されており、ｎ型半導体領域４上にｎ型用電極２が形成され、ｐ型半導体領域５上にｐ型用電極３が形成されている。ここで、ｎ型半導体領域４は、ｐ型シリコン基板５２１の裏面から、ｐ型シリコン基板５２１の一部の内部を貫通して、ｐ型シリコン基板５２１の受光面全体に広がっている。さらに、ｎ型用電極２も、ｐ型シリコン基板５２１の裏面から、ｐ型シリコン基板５２１の一部の内部を貫通して、ｐ型シリコン基板５２１の受光面のｎ型半導体領域４に電気的に接続されている。すなわち、裏面電極型太陽電池セル１のｐ型シリコン基板５２１の裏面において、ライン状に配列されている電極のうち、第２方向の最も外側に配置されているｎ型用電極２は、ｐ型シリコン基板５２１の受光面のｎ型半導体領域４に電気的に接続されている。 14B, the n-type semiconductor region 4 and the p-type semiconductor region 5 are formed on the back surface of the p-type silicon substrate 521, and the n-type electrode 2 is formed on the n-type semiconductor region 4. The p-type electrode 3 is formed on the p-type semiconductor region 5. Here, the n-type semiconductor region 4 extends from the back surface of the p-type silicon substrate 521 through a part of the p-type silicon substrate 521 to the entire light receiving surface of the p-type silicon substrate 521. Further, the n-type electrode 2 also passes through the inside of a part of the p-type silicon substrate 521 from the back surface of the p-type silicon substrate 521 and is electrically connected to the n-type semiconductor region 4 on the light-receiving surface of the p-type silicon substrate 521. It is connected to the. That is, among the electrodes arranged in a line on the back surface of the p-type silicon substrate 521 of the back electrode type solar cell 1, the n-type electrode 2 arranged on the outermost side in the second direction is p-type. The silicon substrate 521 is electrically connected to the n-type semiconductor region 4 on the light receiving surface.
　ＭＷＴ型の裏面電極型太陽電池セル１を用いて太陽電池ストリングを形成した場合にはＥＷＴ型の裏面電極型太陽電池セル１を用いた実施の形態４の太陽電池ストリングと同様の構造をとることにより、実施の形態４の太陽電池ストリングと同様の効果が得られる。 When the solar cell string is formed using the MWT type back electrode type solar cell 1, the same structure as that of the solar cell string according to the fourth embodiment using the EWT type back electrode type solar cell 1 is taken. Thus, the same effect as that of the solar cell string of the fourth embodiment can be obtained.
　なお、実施の形態４および実施の形態５においては、ｐ型シリコン基板を用いた場合について説明したが、ｎ型シリコン基板を用いることもできる。ｎ型シリコン基板を用いた場合には、第２方向において隣り合う裏面電極型太陽電池セル１のそれぞれの向かい合う端部において裏面電極型太陽電池セル１の端部に最も近い電極は、ともに同一の導電型用の電極であるｐ型用電極３となり、他の構造は、ｐ型シリコン基板を用いた場合と同様である。また、配線基材６も、ｎ型シリコン基板を用いた場合に形成される電極の形状に合わせた配線が配置された構造を有することは言うまでもない。 In the fourth and fifth embodiments, the case where a p-type silicon substrate is used has been described. However, an n-type silicon substrate can also be used. In the case where an n-type silicon substrate is used, the electrodes closest to the end of the back electrode type solar cell 1 at the opposite end portions of the back electrode type solar cells 1 adjacent in the second direction are both the same. It becomes the p-type electrode 3 which is an electrode for conductivity type, and the other structure is the same as the case where a p-type silicon substrate is used. Needless to say, the wiring substrate 6 also has a structure in which wirings are arranged in accordance with the shape of the electrodes formed when an n-type silicon substrate is used.
　実施の形態１～５の太陽電池ストリングの受光面側に封止材となるＥＶＡ（エチレンビニルアセテート）フィルムを設置し、その上に透明基材であるガラスを設置して加熱することにより、太陽電池モジュールが作製される。 By installing an EVA (ethylene vinyl acetate) film serving as a sealing material on the light-receiving surface side of the solar cell strings of Embodiments 1 to 5, and placing glass as a transparent substrate thereon and heating the solar cell string, A battery module is produced.
　また、実施の形態１～５においては、裏面電極型太陽電池セル間を配線基材を用いて接続した太陽電池ストリングについて説明したが、裏面電極型太陽電池セル間をインターコネクタで接続して太陽電池ストリングを形成した場合も上記と同様の効果を得ることができる。なお、インターコネクタとしては、たとえば、裏面電極型太陽電池セル間を電気的に接続する金属材料で形成されたものなどを用いることができる。 Further, in the first to fifth embodiments, the solar cell string in which the back electrode type solar cells are connected using the wiring base material has been described. However, the back electrode type solar cells are connected to each other by an interconnector. Even when the battery string is formed, the same effect as described above can be obtained. In addition, as an interconnector, what was formed with the metal material which electrically connects between back electrode type solar cells, for example can be used.
　以上のように本発明の実施の形態について説明を行なったが、上述の各実施の形態の構成を適宜組み合わせることも当初から予定している。 As described above, the embodiments of the present invention have been described, but it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments.
　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。本発明の範囲は上記した説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味およ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 embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
　本発明は、太陽電池ストリングおよび太陽電池モジュールに利用することができる。 The present invention can be used for solar cell strings and solar cell modules.
　１　裏面電極型太陽電池セル、２　ｎ型用電極、３　ｐ型用電極、４　ｎ型半導体領域、５　ｐ型半導体領域、６　配線基材、７　ｎ配線、８　ｐ配線、９　接続配線、１０　太陽電池ストリング、１３　ｎ型半導体領域、１６　絶縁性基材、２１　ｎ型シリコン基板、５２１　ｐ型シリコン基板、１０１　太陽電池セル、１０２　ｎ電極、１０３　ｐ電極、１０４　ｎ+層、１０５　ｐ+層、１０６　配線基板、１０７　ｎ配線、１０８　ｐ配線、１０９　接続配線、１１０　太陽電池ストリング、１１６　絶縁性基板、１２１　シリコン基板。 1 back electrode type solar cell, 2 n type electrode, 3 p type electrode, 4 n type semiconductor region, 5 p type semiconductor region, 6 wiring substrate, 7 n wiring, 8 p wiring, 9 connection wiring, 10 Solar cell string, 13 n-type semiconductor region, 16 insulating substrate, 21 n-type silicon substrate, 521 p-type silicon substrate, 101 solar cell, 102 n-electrode, 103 p-electrode, 104 n + layer, 105 p + layer 106 wiring board, 107 n wiring, 108 p wiring, 109 connection wiring, 110 solar cell string, 116 insulating substrate, 121 silicon substrate.

Claims (6)

  1. 　第１方向と、前記第１方向に直交する第２方向と、にそれぞれ複数ずつ配置された裏面電極型太陽電池セル（１）を含み、
    　前記裏面電極型太陽電池セル（１）は、シリコン基板（２１）と、前記シリコン基板（２１）の受光面と反対側の裏面に設けられた第１導電型用電極（２）および第２導電型用電極（３）と、を有し、
    　前記第１導電型用電極（２）は、前記シリコン基板（２１）の前記裏面の前記第１方向に沿って配置され、
    　前記第２導電型用電極（３）は、前記シリコン基板（２１）の前記裏面の前記第１方向に沿って前記第１導電型用電極（２）と間隔を空けて配置されており、
    　前記第２方向に隣り合う前記裏面電極型太陽電池セル（１）は、前記裏面電極型太陽電池セル（１）の端部に最も近い電極同士が同一の導電型であるように配置されている、太陽電池ストリング（１０）。     A plurality of back electrode solar cells (1) disposed in each of the first direction and the second direction orthogonal to the first direction;
    The back electrode type solar cell (1) includes a silicon substrate (21), a first conductivity type electrode (2) and a second conductivity provided on the back surface opposite to the light receiving surface of the silicon substrate (21). A mold electrode (3),
    The first conductivity type electrode (2) is disposed along the first direction of the back surface of the silicon substrate (21),
    The second conductivity type electrode (3) is disposed at a distance from the first conductivity type electrode (2) along the first direction of the back surface of the silicon substrate (21).
    The said back electrode type photovoltaic cell (1) adjacent to the said 2nd direction is arrange | positioned so that the electrodes nearest to the edge part of the said back electrode type photovoltaic cell (1) may be the same conductivity types. The solar cell string (10).
  2. 　前記シリコン基板（２１）は第１導電型であり、
    　前記裏面電極型太陽電池セル（１）の端部に最も近い前記電極は、前記第１導電型用電極（２）である、請求項１に記載の太陽電池ストリング（１０）。     The silicon substrate (21) is of the first conductivity type,
    The solar cell string (10) according to claim 1, wherein the electrode closest to the end of the back electrode type solar cell (1) is the first conductivity type electrode (2).
  3. 　前記裏面電極型太陽電池セル（１）は、前記シリコン基板（２１）の前記受光面に受光面不純物半導体層（１３）を有している、請求項１または２に記載の太陽電池ストリング（１０）。 The solar cell string (10) according to claim 1 or 2, wherein the back electrode type solar cell (1) has a light receiving surface impurity semiconductor layer (13) on the light receiving surface of the silicon substrate (21). ).
  4. 　前記裏面電極型太陽電池セル（１）の端部に最も近い前記電極は、前記受光面不純物半導体層（１３）に電気的に接続されている、請求項３に記載の太陽電池ストリング（１０）。 The solar cell string (10) according to claim 3, wherein the electrode closest to the end of the back electrode type solar cell (1) is electrically connected to the light receiving surface impurity semiconductor layer (13). .
  5. 　配線基材（６）をさらに含み、
    　前記裏面電極型太陽電池セル（１）は、前記配線基材（６）上に配置されており、
    　前記配線基材（６）は、第１導電型用配線（７）と、第２導電型用配線（８）と、を有し、
    　前記第１導電型用電極（２）は、前記第１導電型用配線（７）と電気的に接続され、
    　前記第２導電型用電極（３）は、前記第２導電型用配線（８）と電気的に接続されている、請求項１から４のいずれかに記載の太陽電池ストリング（１０）。     Further comprising a wiring substrate (6),
    The back electrode type solar cell (1) is disposed on the wiring substrate (6),
    The wiring substrate (6) includes a first conductivity type wiring (7) and a second conductivity type wiring (8),
    The first conductivity type electrode (2) is electrically connected to the first conductivity type wiring (7),
    The solar cell string (10) according to any one of claims 1 to 4, wherein the second conductivity type electrode (3) is electrically connected to the second conductivity type wiring (8).
  6. 　請求項１から５のいずれかに記載の太陽電池ストリング（１０）と、
    　透明基材と、
    　前記太陽電池ストリング（１０）と前記透明基材との間の封止材と、を含む、太陽電池モジュール。     A solar cell string (10) according to any of claims 1 to 5,
    A transparent substrate;
    The solar cell module containing the sealing material between the said solar cell string (10) and the said transparent base material.
PCT/JP2011/079777 2010-12-28 2011-12-22 Solar cell string and solar cell module WO2012090849A1 (en)

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