WO2017026016A1 - Élément de batterie solaire et procédé de fabrication d'élément de batterie solaire - Google Patents

Élément de batterie solaire et procédé de fabrication d'élément de batterie solaire Download PDF

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Publication number
WO2017026016A1
WO2017026016A1 PCT/JP2015/072560 JP2015072560W WO2017026016A1 WO 2017026016 A1 WO2017026016 A1 WO 2017026016A1 JP 2015072560 W JP2015072560 W JP 2015072560W WO 2017026016 A1 WO2017026016 A1 WO 2017026016A1
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Prior art keywords
grid electrode
surface side
impurity diffusion
diffusion layer
back surface
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PCT/JP2015/072560
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English (en)
Japanese (ja)
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隼人 幸畑
濱本　哲
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三菱電機株式会社
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Priority to KR1020187005766A priority Critical patent/KR101981903B1/ko
Priority to JP2017534044A priority patent/JP6395941B2/ja
Priority to PCT/JP2015/072560 priority patent/WO2017026016A1/fr
Publication of WO2017026016A1 publication Critical patent/WO2017026016A1/fr

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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
    • H01L31/02—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
    • H01L31/022433—Particular geometry of the grid contacts
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
    • H01L31/068—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN homojunction type, e.g. bulk silicon PN homojunction solar cells or thin film polycrystalline silicon PN homojunction solar cells
    • 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
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • 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 having a grid electrode and a method for manufacturing the solar cell.
  • the back surface field layer is a selective diffusion layer.
  • the back side electrode and the back side high concentration must be formed unless an electrode is formed on the back side high concentration diffusion layer in which impurities are diffused to a high concentration in the back surface field layer. Insufficient electrical connection with the diffusion layer causes a decrease in the characteristics of the solar battery cell.
  • Patent Document 1 discloses a solar cell in which connection protrusions are formed on finger electrodes.
  • Patent Document 1 discloses a solar cell in which a back-side electrode includes a bus bar electrode, a finger electrode, and a connection protrusion that protrudes from the finger electrode in a direction intersecting the finger electrode.
  • Such a connection protrusion of the solar cell of Patent Document 1 can be used even when the backside high-concentration diffusion layer and the finger electrode are displaced due to a process error or the like during alignment between the backside high-concentration diffusion layer and the finger electrode. It plays a role of electrically connecting the side high concentration diffusion layer and the finger electrode.
  • the finger electrode is partially provided with a protruding portion.
  • the finger electrode is usually formed by printing and baking an electrode material paste containing a metal material.
  • the metal material which occupies most of the cost of a finger electrode is an expensive material in the material which comprises a photovoltaic cell.
  • silver (Ag) is often used for finger electrodes, but silver is an expensive material among metal materials.
  • the present invention has been made in view of the above, and can reduce a decrease in photoelectric conversion efficiency due to electrical connection between an electrode and a high-concentration diffusion layer while reducing the amount of electrode material used. And it aims at obtaining the manufacturing method of a photovoltaic cell.
  • the present invention provides a solar cell in which a first conductivity type semiconductor substrate and an impurity element of a first conductivity type or a second conductivity type on one surface side of the semiconductor substrate are provided. And a paste electrode disposed on one side and electrically connected to the impurity diffusion layer, extending in parallel at a first arrangement interval in a specific direction in the surface direction of the semiconductor substrate.
  • a plurality of grid electrodes having a linear shape.
  • the impurity diffusion layer includes a first conductive type or second conductive type impurity element at a first concentration in a lower region of the grid electrode and has a linear shape, and extends parallel to a specific direction in the plane direction of the semiconductor substrate.
  • the grid electrode protrudes from the side surface of the grid electrode in a direction intersecting with the extending direction of the grid electrode, and has a plurality of connecting protruding portions that are divided and arranged along the extending direction of the grid electrode.
  • the plurality of connecting protrusions are characterized in that the protrusion length from the side surface of the grid electrode becomes longer as the distance from the specific reference position on the one surface side of the semiconductor substrate in the extending direction of the grid electrode is increased.
  • the solar battery cell according to the present invention has an effect that the decrease in photoelectric conversion efficiency due to the electrical connection between the electrode and the high concentration diffusion layer can be suppressed while reducing the amount of the electrode material used.
  • FIG. 2 is a schematic cross-sectional view of a main part of a solar battery cell according to an embodiment of the present invention, and a cross-sectional view of the main part of the solar battery cell in the AA direction of FIG.
  • the principal part top view which expands and shows the back surface side grid electrode of the photovoltaic cell concerning embodiment of this invention.
  • the principal part top view which expands and shows the back surface side high concentration impurity diffusion layer of the photovoltaic cell concerning embodiment of this invention The schematic diagram explaining the back surface side grid electrode of the photovoltaic cell concerning embodiment of this invention.
  • the schematic diagram which shows the pattern of the back surface side grid electrode used when the back surface side grid electrode concerning embodiment of this invention tends to produce the position shift of a formation position in the direction rotated clockwise centering on the center position C The principal part cross-section schematic diagram of the photovoltaic cell which made the light-receiving surface side impurity diffusion layer concerning embodiment of this invention the selective diffusion layer structure
  • FIG. 1 is a schematic top view of a solar battery cell 1 according to an embodiment of the present invention as viewed from the light-receiving surface side.
  • FIG. 2 is a schematic bottom view of the solar battery cell 1 according to the embodiment of the present invention as viewed from the back side facing the light receiving surface.
  • FIG. 3 is a schematic cross-sectional view of the main part of the solar battery cell 1 according to the embodiment of the present invention, and is a cross-sectional view of the main part of the solar battery cell 1 in the AA direction of FIG.
  • the p-type light-receiving surface side impurity diffusion layer 3 in which boron (B), which is a p-type impurity of the second conductivity type, is diffused is of the first conductivity type.
  • a semiconductor substrate 11 having a pn junction is formed over the entire light-receiving surface of an n-type semiconductor substrate 2.
  • An antireflection film 4 made of an insulating film is formed on the light receiving surface side impurity diffusion layer 3. In this solar battery cell 1, light L enters from the antireflection film 4 side.
  • an n-type single crystal silicon substrate is used as the semiconductor substrate 2.
  • the semiconductor substrate 2 made of an n-type single crystal silicon substrate may be referred to as an n-type silicon substrate 2.
  • the semiconductor substrate 2 is not limited to an n-type single crystal silicon substrate, and an n-type polycrystalline silicon substrate may be used.
  • a texture structure is formed on the light receiving surface side of the n-type silicon substrate 2, that is, on the light receiving surface side of the p-type light receiving surface side impurity diffusion layer 3. Since the fine unevenness of the texture structure is very fine, it is not shown as an uneven shape in FIG. 3 and the following drawings.
  • a plurality of elongated light receiving surface side grid electrodes 5 a are arranged in parallel along a pair of side directions in the semiconductor substrate 11.
  • a plurality of light receiving surface side bus electrodes 5b electrically connected to the light receiving surface side grid electrode 5a are arranged in parallel along the other pair of side directions in the semiconductor substrate 11 in a state orthogonal to the light receiving surface side grid electrode 5a.
  • the light-receiving surface side grid electrode 5a and the light-receiving surface-side bus electrode 5b are electrically connected to the p-type light-receiving surface-side impurity diffusion layer 3 at the bottom surface.
  • the light receiving surface side grid electrode 5a and the light receiving surface side bus electrode 5b are made of an electrode material containing silver.
  • the light-receiving surface side grid electrode 5a and the light-receiving surface-side bus electrode 5b constitute a light-receiving surface-side electrode 5 that is a first electrode having a comb shape.
  • the light receiving surface side grid electrode 5a has a width of, for example, about 40 ⁇ m or more and 70 ⁇ m or less, and is arranged in parallel with a predetermined interval of 70 or more and 300 or less, and collects electricity generated inside the semiconductor substrate 11. Electricity.
  • the light receiving surface side bus electrode 5b has a width of, for example, about 0.5 mm or more and 1.0 mm or less, and two or more and 5 or less are arranged per solar cell, and the light receiving surface side grid The electricity collected by the electrode 5a is taken out to the outside.
  • the number of light receiving surface side grid electrodes 5a is more preferably 100 or more and 200 or less.
  • the n-type backside impurity diffusion layer 7 in which phosphorus (P) is diffused is opposed to the light-receiving surface of the n-type semiconductor substrate 2 on the surface layer on the backside that is the surface facing the light-receiving surface in the semiconductor substrate 2.
  • the BSF layer is formed on the entire back surface.
  • a backside insulating film 8 made of an insulating film is formed on the backside impurity diffusion layer 7.
  • a plurality of long and narrow back surface side grid electrodes 6 a are arranged in parallel along a pair of side directions in the semiconductor substrate 11 on the back surface side impurity diffusion layer 7.
  • a plurality of backside bus electrodes 6b electrically connected to the backside grid electrode 6a are arranged in parallel along the other pair of side directions in the semiconductor substrate 11 in a state orthogonal to the backside grid electrode 6a.
  • the back-side grid electrode 6a and the back-side bus electrode 6b are formed on a back-side high-concentration impurity diffusion layer 7a of an n-type back-side impurity diffusion layer 7 to be described later, and each has an n-type back-side impurity diffusion at the bottom.
  • the back surface side high concentration impurity diffusion layer 7a of the layer 7 is electrically connected.
  • the back side grid electrode 6a and the back side bus electrode 6b are made of an electrode material containing silver.
  • the back-side grid electrode 6a and the back-side bus electrode 6b constitute a back-side electrode 6 that is a second electrode having a comb shape.
  • the back surface side grid electrode 6a has a width of, for example, about 40 ⁇ m or more and 70 ⁇ m or less, and 70 or more and 300 or less are arranged in parallel at predetermined intervals, and collects electricity generated inside the semiconductor substrate 11 To do. Further, the back-side bus electrode 6b has a width of, for example, about 0.5 mm or more and 1.0 mm or less, and two or more and 5 or less are arranged per solar cell, and the back-side grid electrode 6a. Take out the electricity collected at the outside.
  • the number of backside grid electrodes 6a is more preferably 100 or more and 200 or less.
  • the n-type backside impurity diffusion layer 7 is an n-type impurity diffusion layer in which phosphorus is diffused as an n-type impurity in the surface layer on the backside of the semiconductor substrate 2.
  • two types of layers are formed as the n-type backside impurity diffusion layer 7 to form a selective diffusion layer structure. That is, in the surface layer portion on the back surface side of the n-type silicon substrate 2, n-type impurities are diffused at a relatively high concentration in the back surface side impurity diffusion layer 7 in the lower region of the back surface side electrode 6 and its peripheral region.
  • a back side high concentration impurity diffusion layer 7a which is a first impurity diffusion layer is formed.
  • n-type impurities are relatively low in the back-side impurity diffusion layer 7 in a region where the back-side high-concentration impurity diffusion layer 7 a is not formed.
  • a back-side low-concentration impurity diffusion layer 7b which is a second impurity diffusion layer that is uniformly diffused, is formed.
  • the back side high concentration impurity diffusion layer 7a is a low resistance diffusion layer having a lower electrical resistance than the back side low concentration impurity diffusion layer 7b.
  • the back side low concentration impurity diffusion layer 7b is a high resistance diffusion layer having a higher electrical resistance than the back side high concentration impurity diffusion layer 7a.
  • the back-side impurity diffusion layer 7 is configured by the back-side high-concentration impurity diffusion layer 7a and the back-side low-concentration impurity diffusion layer 7b.
  • the second concentration is lower than the first concentration.
  • the electrical resistance value of the back side high concentration impurity diffusion layer 7a is the first electrical resistance value and the electrical resistance value of the back side low concentration impurity diffusion layer 7b is the second electrical resistance value, the second electrical resistance value is It becomes larger than the first electric resistance value.
  • backside low-concentration impurity diffusion layer 7b suppresses carrier recombination on the backside of n-type silicon substrate 2 as a BSF layer. Therefore, a good open circuit voltage can be obtained. Moreover, since the back surface side high concentration impurity diffusion layer 7a reduces the contact resistance of the back surface side impurity diffusion layer 7 and the back surface side electrode 6, a favorable curve factor can be obtained.
  • FIG. 4 is an enlarged plan view showing a main part of the back surface side grid electrode 6a of the solar battery cell 1 according to the embodiment of the present invention.
  • FIG. 5 is an enlarged plan view showing a main part of the back surface side high-concentration impurity diffusion layer 7a of the solar battery cell 1 according to the embodiment of the present invention.
  • FIG. 6 is a schematic diagram for explaining the back surface side grid electrode 6a of the solar battery cell 1 according to the embodiment of the present invention.
  • the back surface side grid electrodes 6 a have an elongated shape as a basic shape, and are arranged in parallel with each other at a predetermined first arrangement interval D ⁇ b> 1 along a pair of side directions of the semiconductor substrate 11. ing.
  • the back surface side grid electrode 6a has a plurality of connecting projections 6t formed on both side surfaces of the back surface side grid electrode 6a.
  • the connecting protrusion 6t protrudes from both side surfaces of the back surface side grid electrode 6a in a direction intersecting the longitudinal direction of the back surface side grid electrode 6a.
  • a plurality of connection protrusions 6t are divided and arranged along the longitudinal direction of the back surface side grid electrode 6a at a predetermined second arrangement interval D2.
  • the connecting protrusion 6 t protrudes in a direction orthogonal to the longitudinal direction of the back surface side grid electrode 6 a in the surface direction of the semiconductor substrate 11.
  • Such a connecting protrusion 6t is formed on the backside high-concentration impurity diffusion when misalignment occurs during alignment between the backside high-concentration impurity diffusion layer 7a and the backside electrode 6 when the backside grid electrode 6a is formed. It has a function of assisting electrical connection between the layer 7a and the backside grid electrode 6a.
  • the long and narrow back side high-concentration impurity diffusion layer 7a has the same width and the same shape as the long and narrow part except for the connecting projection 6t in the back side grid electrode 6a. That is, the width 6aW of the back surface side grid electrode is the same as the width 7W of the back surface high concentration impurity diffusion layer. And the elongate elongated shape part of the back surface side grid electrode 6a is overlapped and formed on the back surface side high concentration impurity diffusion layer 7a.
  • the width 6aW of the back surface side grid electrode in this specification is the width of the long and narrow shape portion excluding the connection protrusion 6t in the back surface side grid electrode 6a, and includes the protrusion of the connection protrusion 6t. Not in. Therefore, the connecting protrusion 6t protrudes from the side surface of the back surface side high concentration impurity diffusion layer 7a and is formed on the back surface side low concentration impurity diffusion layer 7b.
  • the width 7W of the backside high-concentration impurity diffusion layer to which the backside grid electrode 6a is electrically connected is the minimum necessary, that is, the same width as the width 6aW of the backside grid electrode.
  • the protruding portion 6t for connection has a larger protruding amount from the side surface of the back surface side grid electrode 6a as it is away from the specific reference position in the longitudinal direction of the back surface side grid electrode 6a, that is, for connection from the side surface of the back surface side grid electrode 6a.
  • the protrusion length 6tL of the protrusion 6t is longer. Therefore, the protruding portion 6t for connection has a smaller protruding amount as it is closer to a specific reference position in the longitudinal direction of the back surface side grid electrode 6a, that is, the protruding length 6t from the side surface of the back surface side grid electrode 6a is shorter.
  • the specific reference position is a semiconductor substrate that is an alignment position at the time of alignment between the back-side high-concentration impurity diffusion layer 7a and the back-side electrode 6 when the back-side grid electrode 6a is formed.
  • 11 is the center position C in the surface direction.
  • the specific reference position is a position where the alignment accuracy between the back side high-concentration impurity diffusion layer 7a and the back side electrode 6 is the highest.
  • a virtual line V passing through the center position C and orthogonal to the longitudinal direction of the back surface side grid electrode 6a can be considered as a specific reference position.
  • the alignment position at the time of alignment is the center position C in the surface direction of the semiconductor substrate 11, but the alignment position at the time of alignment is not limited to this, and an arbitrary position in the plane of the semiconductor substrate 11. Is possible. Also in this case, the alignment position at the time of alignment becomes a specific reference position.
  • the protrusion 6t for connection in the plurality of back surface side grid electrodes 6a has a protrusion length 6tL that is longer from the center position C in the longitudinal direction of the back surface side grid electrode 6a. That is, the protrusion 6tL for connection in the plurality of back surface side grid electrodes 6a has a protrusion length 6tL that increases as the distance from the virtual line V orthogonal to each back surface side grid electrode 6a increases.
  • Each of the connecting protrusions 6t in the back surface side grid electrode 6a has a protrusion length 6tL that is directly proportional to the center position C or the distance from the position corresponding to the center position C in the longitudinal direction of the back surface side grid electrode 6a. It is getting longer. Therefore, the protrusion 6t for connection in each back surface side grid electrode 6a has a protrusion length 6tL that is directly proportional to the distance from the position corresponding to the center position C in the longitudinal direction of the back surface side grid electrode 6a. .
  • the protrusion 6t for connection in the plurality of back surface side grid electrodes 6a has a protrusion length 6tL that decreases in the longitudinal direction of the back surface side grid electrode 6a from the end of the solar cell 1 to the center position C. It has become. That is, the connecting protrusions 6t in the plurality of backside grid electrodes 6a are virtual lines V orthogonal to the respective backside grid electrodes 6a from the end of the solar cell 1 in the longitudinal direction of the backside grid electrode 6a.
  • the protrusion length 6 tL is shortened as the distance from the point approaches.
  • the center position C which is a specific reference position in the surface direction of the semiconductor substrate 11, is used when aligning the formation position of the back surface side electrode 6 with respect to the back surface side high concentration impurity diffusion layer 7a when forming the back surface side grid electrode 6a.
  • the position where the back surface side grid electrode 6a is formed is displaced in the direction of rotation around the center.
  • the overlay accuracy of the back surface side grid electrode 6a with respect to the back surface side high concentration impurity diffusion layer 7a becomes high.
  • the overlay accuracy of the back surface side grid electrode 6a on the back surface side high concentration impurity diffusion layer 7a may be referred to as overlay accuracy. That is, each back surface side grid electrode 6a has high overlay accuracy at a position near the virtual line V. For this reason, the connection protrusion 6t is almost unnecessary at a position near the virtual line V, and the protrusion length 6tL may be short.
  • each back surface side grid electrode 6a is low at a position far from the virtual line V. That is, the shift amount of the back surface side grid electrode 6a located far from the virtual line V with respect to the back surface side high concentration impurity diffusion layer 7a is different from the back surface side high concentration impurity diffusion layer 7a of the back surface side grid electrode 6a located near the virtual line V. It becomes larger than the amount of deviation. Then, the shift amount of the end portion of the back surface side grid electrode 6a farthest from the virtual line V becomes the largest.
  • the protrusion length 6tL of the connection protrusion 6t in the back surface side high concentration impurity diffusion layer 7a is increased as the distance from the virtual line V increases.
  • the impurity diffusion layer 7a and the back surface side grid electrode 6a can be electrically connected by the connecting protrusion 6t.
  • the contact area of the back surface side grid electrode 6a and the back surface side high concentration impurity diffusion layer 7a reduced by having shifted the back surface side grid electrode 6a from the back surface side high concentration impurity diffusion layer 7a can be increased.
  • FIG. 7 shows electrical connection by the connecting protrusion 6t when an overlay error of the back surface side grid electrode 6a with respect to the back surface side high concentration impurity diffusion layer 7a occurs in the solar cell 1 according to the embodiment of the present invention. It is a top view for demonstrating a principle.
  • FIG. 7 shows the region on the right side of the virtual line V in the back surface side grid electrode 6a, the same applies to the region on the left side of the virtual line V.
  • the back surface side grid electrode 6a is shifted to the lower side of the back surface side high concentration impurity diffusion layer 7a.
  • the back surface side high concentration impurity diffusion layer 7a and the back surface side grid electrode 6a can be electrically connected by the connection protrusion 6t protruding from the upper side surface of the back surface side grid electrode 6a.
  • the back side grid electrode 6a can be thinned. And the amount of the metal material used for the back surface side grid electrode 6a can be reduced by aiming at thinning of the back surface side grid electrode 6a, and the fall of the cost of the back surface side grid electrode 6a and the photovoltaic cell 1 is realizable.
  • the protrusion length 6tL of the connecting protrusion 6t according to the distance from the center position C or the virtual line V in the longitudinal direction of the back surface side grid electrode 6a, the back surface side grid electrode 6a
  • the amount of the metal material used can be reduced, and the cost of the back side grid electrode 6a and the solar battery cell 1 can be reduced.
  • the protrusion length 6tL of the connecting protrusion 6t according to the distance from the imaginary line V grasps the tendency of the position shift of the formation position of the back surface side grid electrode 6a in the direction of rotation about the center position C. Therefore, it can be set appropriately.
  • the solar cell 1 even when the formation position of the back surface side grid electrode 6a is shifted from the back surface side high concentration impurity diffusion layer 7a in the direction of rotation about the center position C.
  • the backside high-concentration impurity diffusion layer 7a and the backside grid electrode 6a can be electrically connected by the connecting protrusion 6t.
  • the width 7W of the back-side high-concentration impurity diffusion layer can be made the minimum necessary, that is, the same width as the width 6aW of the back-side grid electrode.
  • region of the back surface side low concentration impurity diffusion layer 7b in the back surface side impurity diffusion layer 7 can be increased, and a back surface passivation effect can be increased.
  • the protruding lengths 6tL of all the connecting protruding portions 6t are made equal in the longitudinal direction of the back surface side grid electrode 6a, the above effect becomes very small.
  • the protrusion length 6tL of all the connection protrusions 6t is set to be small in accordance with the connection protrusion 6t on the virtual line V side, the protrusion length 6tL is short.
  • the connection between the back surface side high concentration impurity diffusion layer 7a and the back surface side grid electrode 6a by the connecting protrusion 6t The area becomes smaller or disappears.
  • the protruding lengths 6tL of all the connecting protrusions 6t are matched with the protruding length 6tL of the connecting protruding part 6t near the virtual line V, for example, and the position where the overlapping accuracy is high. If the distance is shorter than the imaginary line V, the connection area between the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a by the connecting protrusion 6t is small on the end side where the overlay accuracy is low. Or disappear. In this case, the electrical connection between the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a becomes insufficient, and the contact resistance increases.
  • the protrusion length 6 tL of all the connection protrusions 6 t is large in accordance with the protrusion length 6 tL of the connection protrusion 6 t at the position on the end side that is far from the imaginary line V and has low overlay accuracy.
  • the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a can be electrically connected by the connecting protrusion 6t even in the vicinity of the end of the back-side grid electrode 6a.
  • the connecting protrusion 6t increases, the recombination of carriers on the back surface of the semiconductor substrate 11 increases, and the amount of the metal material used for the connecting protrusion 6t increases.
  • the cost of the back surface side grid electrode 6a and the photovoltaic cell 1 increases.
  • the width 6tW of the connection protrusions is the same in all the connection protrusions 6t, and is equal to or less than the width 6aW of the back surface side grid electrode.
  • the ratio of the width 6tW of the connecting protrusion to the width 6aW of the back surface side grid electrode: 6tW / 6aW is set to 0.3 or more and 1 or less.
  • the ratio: 6tW / 6aW is less than 0.3, since the width 6tW of the connecting protrusion is small, the electrical connection between the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a by the connecting protrusion 6t. There is a risk that the target connection area will be insufficient.
  • the connecting protrusion 6t has a large width 6tW, so that the area of the connecting protrusion 6t increases, and carriers are recombined on the back surface of the semiconductor substrate 11. May increase and the characteristics of the solar battery cell 1 may deteriorate.
  • the ratio: 6tW / 6aW depends on various conditions such as the size of the solar cell 1, the type of the solar cell 1, the constituent material of the back side grid electrode 6a, the impurity concentration of the back side high concentration impurity diffusion layer 7a, and the like. It can be set appropriately as appropriate.
  • the protruding length 6tL of the connecting protrusion 6t from the side surface of the back side grid electrode 6a is made smaller than the first arrangement interval D1, which is the arrangement interval between the adjacent back side grid electrodes 6a. Further, the projecting lengths 6tL of the two connecting projecting parts 6t facing each other across the long and narrow shaped part are the same.
  • the ratio of the projection length 6 tL to the first arrangement interval D1: 6 tL / D1 is 0.6 or less. When the ratio: 6tL / D1 is larger than 0.6, the connecting protrusions 6t of the adjacent back surface side grid electrodes 6a may be connected to each other.
  • interval D1 shall be about 0.5 mm or more and 2.0 mm or less.
  • the second arrangement interval D2 is about 0.5 mm or more and 2.0 mm or less.
  • the connecting protrusions 6t are densely positioned in the longitudinal direction of the back surface side grid electrode 6a, and the area of the back surface side grid electrode 6a is increased. The characteristics of the solar battery cell 1 may be deteriorated.
  • the second arrangement interval D2 is larger than 2.0 mm, the electrical connection area between the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a by the connecting protrusion 6t may be insufficient. .
  • the ratio: 6 tL / D1 is 0.05 or more and 0.3 or less.
  • the ratio: 6tL / D1 is less than 0.05, the protruding length 6tL is small, so that the connecting protruding portion against the overlay error of the back side grid electrode 6a with respect to the back side high concentration impurity diffusion layer 7a.
  • the back side high concentration impurity diffusion layer 7a and the back side grid electrode 6a cannot be electrically connected by 6t.
  • the ratio: 6tL / D1 is larger than 0.3, the protruding length 6tL becomes unnecessarily long, and the area of the connecting protruding portion 6t may become unnecessarily large.
  • the ratio: 6 tL / D1 is appropriate according to the distance from the imaginary line V by grasping the tendency of the position shift of the formation position of the back surface side grid electrode 6a in the direction of rotation about the center position C. Can be set.
  • a plurality of connecting protrusions 6t are arranged along the longitudinal direction of the back surface side grid electrode 6a at a predetermined second arrangement interval D2.
  • the plurality of connecting protrusions 6t are arranged at the second arrangement interval D2 from the imaginary line V side toward the both end parts across the imaginary line V in the back surface side grid electrode 6a.
  • the second arrangement interval D2 is made larger than the width 6tW of the back surface side grid electrode.
  • the connecting protrusions 6t are densely positioned in the longitudinal direction of the back surface side grid electrode 6a. There is a possibility that the area is increased and the characteristics of the solar battery cell 1 are deteriorated.
  • the concentration of the back-side low-concentration impurity diffusion layer 7b is reduced and the back-side low concentration of the back-side impurity diffusion layer 7 is reduced. It is important to increase the ratio of the impurity diffusion layer 7b. In other words, the reduction in the ratio of the region of the back-side high-concentration impurity diffusion layer 7 a in the back-side impurity diffusion layer 7 greatly contributes to the output improvement of the solar battery cell 1. This is due to carrier recombination in the surface layer on the back surface of the semiconductor substrate 11.
  • the back surface side high concentration impurity diffusion layer 7a corresponding to the back surface side grid electrode 6a, that is, the back surface side high concentration impurity diffusion layer to which the back surface side grid electrode 6a is electrically connected has a minimum width 7W, that is, the back surface side grid electrode.
  • the structure of the solar cell 1 that secures the electrical connection between the back-side high-concentration impurity diffusion layer 7a and the back-side grid electrode 6a by the connecting protrusion 6t is substantially equivalent to the width 6aW of large.
  • the protrusion length 6tL is changed in direct proportion to the distance from the virtual line V orthogonal to the back surface side high concentration impurity diffusion layer 7a as described above. It is possible to reduce the thickness of the electrode 6a, and further contribute to reducing the width 7W of the back-side high-concentration impurity diffusion layer.
  • the width 7W of the back-side high-concentration impurity diffusion layer does not have to be exactly the same width as the width 6aW of the back-side grid electrode, and may be slightly larger than the width 6aW of the back-side grid electrode.
  • the back-side high-concentration impurity diffusion layer 7a that protrudes from the back-side grid electrode 6a causes the characteristics of the solar battery cell 1 to deteriorate, so it is desirable to make it narrow as much as possible.
  • the width 7W of the back-side high-concentration impurity diffusion layer is The width can be increased up to about twice the width 6aW of the electrode. In this case, substantially the same output improvement effect can be obtained as compared with the case where the width 7W of the backside high-concentration impurity diffusion layer is the same as the width 6aW of the backside grid electrode. In this specification, including this range, the width 7W of the backside high-concentration impurity diffusion layer is assumed to be the same as the width 6aW of the backside grid electrode.
  • the width 7W of the back-side high-concentration impurity diffusion layer is wider than the width 6aW of the back-side grid electrode in the above range, the position where the back-side grid electrode 6a is formed in the direction of rotation about the center position C. Even when the positional deviation occurs, the back surface side high concentration impurity diffusion layer 7a and the back surface side grid electrode 6a are compared with the case where the width 6aW of the back surface side grid electrode is the same as the width 7W of the back surface side high concentration impurity diffusion layer. The area of electrical connection with is increased. Therefore, the protrusion length 6tL may be shortened as a whole.
  • FIG. 8 is a flowchart showing a process flow of the method for manufacturing the solar battery cell 1 according to the embodiment of the present invention.
  • 9 to 17 are cross-sectional views of relevant parts for explaining the manufacturing process of the solar battery cell 1 according to the embodiment of the present invention.
  • FIG. 9 is an explanatory diagram of step S10 in FIG.
  • an n-type silicon substrate 2 is prepared as the semiconductor substrate 2, and cleaning and formation of a texture structure are performed.
  • the n-type silicon substrate 2 is manufactured by cutting and slicing the single crystal silicon ingot obtained in the single crystal pulling step into a desired size and thickness using a cutting device such as a band saw or a multi-wire saw.
  • the damage layer at the time of slicing remains. Therefore, the damage layer existing near the surface of the n-type silicon substrate 2 is generated by etching the surface of the n-type silicon substrate 2 to remove the damaged layer, and is generated when the silicon substrate is cut out by surface contamination during slicing.
  • Cleaning to remove is performed. Cleaning is performed, for example, by immersing the n-type silicon substrate 2 in an alkaline solution in which sodium hydroxide of about 1 wt% or more and 10 wt% or less is dissolved.
  • the texture structure is formed by forming minute irregularities on the surface of the first main surface which becomes the light receiving surface in the n-type silicon substrate 2. Since the minute unevenness is very fine, it is not expressed as an uneven shape in FIGS.
  • a chemical solution in which an additive such as isopropyl alcohol or caprylic acid is mixed in an alkaline solution of about 0.1 wt% or more and 10 wt% or less is used.
  • an additive such as isopropyl alcohol or caprylic acid
  • an alkaline solution of about 0.1 wt% or more and 10 wt% or less
  • the texture structure may be formed not only on the light receiving surface of the n-type silicon substrate 2 but also on the back surface of the n-type silicon substrate 2. Note that the surface contamination and damage layer removal during slicing and the formation of the texture structure may be performed simultaneously.
  • a cleaning method called RCA cleaning is used for cleaning the surface of the n-type silicon substrate 2 on which the texture structure is formed.
  • a cleaning method called RCA cleaning for cleaning the surface of the n-type silicon substrate 2, for example, a cleaning method called RCA cleaning is used.
  • RCA cleaning a mixed solution of sulfuric acid and hydrogen peroxide, a hydrofluoric acid aqueous solution, a mixed solution of ammonia and hydrogen peroxide, and a mixed solution of hydrochloric acid and hydrogen peroxide are prepared as cleaning solutions.
  • the organic substance, the metal and the oxide film are removed by combining the cleaning with the cleaning liquid.
  • cleaning liquids of the above-described cleaning liquid types instead of using all the cleaning liquids of the above-described cleaning liquid types, a combination of cleaning with one or a plurality of cleaning liquids may be used.
  • a mixed solution of hydrofluoric acid and hydrogen peroxide water and water containing ozone may be included as the cleaning liquid.
  • each cleaning solution itself does not cause contamination of other cleaning solutions or unintentional reaction between cleaning solutions or silicon, and to ensure safety after removal from the cleaning device.
  • the n-type silicon substrate 2 is washed with pure water or the like at an arbitrary timing such as during the process or before the n-type silicon substrate 2 is dried.
  • FIG. 10 is an explanatory diagram of step S20 of FIG.
  • Step S20 is a process of forming a pn junction by forming a p-type impurity diffusion layer 3a on the surface of the n-type silicon substrate 2.
  • the p-type impurity diffusion layer 3a is formed by placing the n-type silicon substrate 2 having a textured structure in a thermal diffusion furnace and in the presence of boron tribromide (BBr 3 ) vapor or boron trichloride (BCl 3 ). Realized by heat treatment in the presence of steam.
  • BBr 3 boron tribromide
  • BCl 3 boron trichloride
  • a p-type impurity diffusion layer 3a On the front and back surfaces of the n-type silicon substrate 2 after the formation of the p-type impurity diffusion layer 3a, a p-type impurity diffusion layer 3a in which boron is diffused at a uniform concentration in the surface direction of the n-type silicon substrate 2, and an oxide film And a boron-containing glass layer (not shown) which is an impurity-containing glass layer containing boron.
  • FIG. 11 is an explanatory diagram of step S30 in FIG.
  • Step S30 is a step of forming the oxide film 21 on the surface of the n-type silicon substrate 2 by thermal oxidation.
  • the purpose of the step S30 is to incorporate a boron-containing glass layer, which is a boron-rich layer formed at the interface between silicon and the oxide film on the surface of the n-type silicon substrate 2, into the oxide film, There is an object to form a diffusion protective film when forming the BSF layer on the back surface of the silicon substrate 2.
  • an oxide film 21 is formed on the surface of the n-type silicon substrate 2 by incorporating the boron-containing glass layer on the surface of the n-type silicon substrate 2.
  • FIG. 12 is an explanatory diagram of step S40 in FIG.
  • Step S40 is a step of removing the oxide film 21 and the p-type impurity diffusion layer 3a, which is an impurity-containing layer, formed on the back surface opposite to the light receiving surface of the n-type silicon substrate 2.
  • the removal of the oxide film 21 and the p-type impurity diffusion layer 3a can be performed by single-sided etching in which only the back surface of the n-type silicon substrate 2 is brought into contact with the hydrofluoric acid aqueous solution using, for example, a single-sided etching apparatus.
  • the p-type impurity diffusion layer 3 a formed on the light-receiving surface side of the n-type silicon substrate 2 becomes the p-type impurity diffusion layer 3.
  • a semiconductor substrate 11 in which a pn junction is formed by an n-type silicon substrate 2 made of n-type single crystal silicon and a p-type impurity diffusion layer 3 formed on the light-receiving surface side of the n-type silicon substrate 2 is formed. can get.
  • n-type impurities are diffused into the back surface of the semiconductor substrate 11, that is, the back surface of the n-type silicon substrate 2, thereby forming a selective diffusion layer.
  • a case of using a phosphorus paste step using a doping paste for forming the backside high-concentration impurity diffusion layer 7a and phosphorus oxychloride (POCl 3 ) for forming the backside low-concentration impurity diffusion layer 7b is used. Will be described.
  • FIG. 13 is an explanatory diagram of step S50 in FIG.
  • Step S50 is a process of selectively printing the phosphorus-containing doping paste 22 on the back surface of the semiconductor substrate 11, that is, on the back surface of the n-type silicon substrate 2, as a doping paste that is an n-type impurity diffusion source.
  • a phosphorus-containing doping paste 22 that is a resin paste containing a phosphorus oxide is selectively printed on the back surface of the n-type silicon substrate 2 as a doping paste using a screen printing method.
  • the printing pattern of the phosphorus-containing doping paste 22 is a region that forms the back surface side electrode 6 formation region and its peripheral region on the back surface of the n-type silicon substrate 2.
  • the phosphorus-containing doping paste 22 is printed in the formation region of the back surface side grid electrode 6a, the formation region of the back surface side bus electrode 6b, and the peripheral region thereof.
  • the printing pattern of the phosphorus-containing doping paste 22 includes, for example, a pattern in which linear patterns having a line width of 150 ⁇ m are arranged in parallel at intervals of 1.5 mm and a pattern in which two linear patterns having a line width of 2.0 mm are arranged in parallel. This is a comb-shaped pattern. After printing, the phosphorus-containing doping paste 22 is dried. In addition, in the principal part sectional drawing of FIG. 13, only the printing pattern of the phosphorus containing doping paste 22 for forming the back side high concentration impurity diffusion layer 7a is shown.
  • FIG. 14 is an explanatory diagram of step S60 of FIG.
  • Step S60 is a process of forming a BSF layer having a selective diffusion layer structure by heat-treating the semiconductor substrate 11 on which the phosphorus-containing doping paste 22 is printed.
  • the semiconductor substrate 11 on which the phosphorus-containing doping paste 22 is printed is placed in a thermal diffusion furnace, and heat treatment is performed in the presence of phosphorus oxychloride (POCl 3 ) vapor.
  • POCl 3 phosphorus oxychloride
  • a boat on which the semiconductor substrate 11 is placed in a horizontal furnace is loaded, and the semiconductor substrate 11 is heat-treated at about 1000 ° C. or more and about 1100 ° C. or less for 30 minutes.
  • phosphorus as a dopant component in the phosphorus-containing doping paste 22 is thermally diffused into the n-type silicon substrate 2 immediately below the phosphorus-containing doping paste 22.
  • the back-side high-concentration impurity diffusion layer 7 a is formed in the surface layer on the back surface of the n-type silicon substrate 2 immediately below the phosphorus-containing doping paste 22.
  • the back-side high-concentration impurity diffusion layer 7 a is formed in the same comb-shaped pattern as the printing pattern of the phosphorus-containing doping paste 22.
  • the dopant component of the phosphorus-containing doping paste 22 does not diffuse in the region other than the region immediately below the phosphorus-containing doping paste 22.
  • phosphorus in phosphorus oxychloride (POCl 3 ) vapor is thermally diffused in the surface layer of the region other than the region immediately below the phosphorus-containing doping paste 22 in the surface layer on the back surface side of the n-type silicon substrate 2.
  • a back-side low-concentration impurity diffusion layer 7b in which phosphorus is diffused at a uniform concentration in the surface direction of the n-type silicon substrate 2 is formed.
  • the back side impurity diffusion layer 7 having the back side high concentration impurity diffusion layer 7a and the back side low concentration impurity diffusion layer 7b which is a BSF layer having a selective diffusion layer structure, is formed.
  • the semiconductor substrate 11 is overlapped with the light receiving surface side of the two semiconductor substrates 11 facing each other so that the light receiving surface side of the semiconductor substrate 11 is not directly exposed to the atmosphere in the thermal diffusion furnace. Is charged. Thereby, the film formation of phosphorous glass on the light receiving surface side of the semiconductor substrate 11 is greatly restricted. Further, an oxide film 21 is formed on the surface of the semiconductor substrate 11 on the light receiving surface side. Since the oxide film 21 functions as a diffusion barrier, it is possible to prevent phosphorus from entering the n-type silicon substrate 2 from the light receiving surface side of the semiconductor substrate 11 from the furnace atmosphere. That is, phosphorus is diffused into the n-type silicon substrate 2 selectively on the back surface, and an n-type impurity diffusion layer is formed on the back surface.
  • step S70 of FIG. 8 the oxide film 21 and the phosphorus-containing doping paste 22 are removed.
  • the removal of the oxide film 21 and the phosphorus-containing doping paste 22 can be performed by immersing the semiconductor substrate 11 in a hydrofluoric acid aqueous solution.
  • step S80 of FIG. 8 the p-type impurity diffusion layer 3 formed on the light receiving surface side of the n-type silicon substrate 2 and the back-side impurity diffusion layer 7 formed on the back surface side of the n-type silicon substrate 2.
  • a pn separation step for electrically separating the two is performed. Specifically, for example, about 50 to 300 semiconductor substrates 11 that have undergone the processes up to step S70 are stacked, and end face etching is performed in which the side surface is etched by plasma discharge. Alternatively, laser separation may be performed in which the n-type silicon substrate 2 is exposed by melting the vicinity of the side edge of the light receiving surface side or the back surface side of the semiconductor substrate 11 or the side surface of the semiconductor substrate 11 by laser irradiation.
  • the separation state between the p-type impurity diffusion layer 3 and the back-side impurity diffusion layer 7, that is, the magnitude of leakage current, the final power generation product Depending on the arrangement of the solar cells in the solar cell module, the pn separation step in step S80 can be omitted.
  • the silicon oxide film formed on the light receiving surface side surface of the semiconductor substrate 11, that is, the surface of the p-type impurity diffusion layer 3 is, for example, using an aqueous hydrofluoric acid solution of 5% to 25%. Removed. Then, the hydrofluoric acid aqueous solution adhering to the surface of the semiconductor substrate 11 is removed by washing with water. At this time, an oxide film formed by washing with water, generally called a natural oxide film, may be used as a passivation layer described later or a part thereof. For the same purpose, an oxide film obtained by cleaning the semiconductor substrate 11 with water containing ozone may be used as a passivation layer described later or a part thereof.
  • FIG. 15 is an explanatory diagram of step S90 of FIG.
  • Step S90 is a step of forming the back surface side insulating film 8 and the antireflection film 4.
  • a silicon nitride film is formed on the back surface of the semiconductor substrate 11, that is, on the back surface side impurity diffusion layer 7 by using, for example, plasma CVD, and a back surface side insulating film 8 made of an insulating film is formed on the back surface of the semiconductor substrate 11. Is done.
  • a passivation layer may be formed between the silicon nitride film of the back-side insulating film 8 and the back-side impurity diffusion layer 7.
  • the passivation layer is preferably a silicon oxide film, and in addition to general thermal oxidation, an oxide film obtained by washing with water or washing with ozone-containing water as described above may be used.
  • an antireflection film 4 made of a silicon nitride film is formed on the light receiving surface side of the semiconductor substrate 11, that is, on the p-type impurity diffusion layer 3 by using, for example, plasma CVD.
  • a passivation layer may be formed between the silicon nitride film of the antireflection film 4 and the p-type impurity diffusion layer 3.
  • the passivation layer is preferably a silicon oxide film or an aluminum oxide film, or a laminated film of a silicon oxide film and an aluminum oxide film.
  • an oxide film obtained by washing with water or washing with ozone-containing water as described above may be used in addition to a general thermal oxide film.
  • the aluminum oxide film is formed, for example, by plasma CVD or ALD (Atomic Layer Deposition).
  • ALD Atomic Layer Deposition
  • a fixed charge included in the film formation is more preferable because it has an effect of enhancing the passivation ability.
  • the order of formation of the backside insulating film 8, the antireflection film 4 and the passivation layer formed on the front and back surfaces of the semiconductor substrate 11 is not necessarily limited to the above order. You may select and form suitably.
  • FIG. 16 is an explanatory diagram of step S100 in FIG.
  • Step S100 is a step of printing the electrodes to form the light-receiving surface side electrode 5 and the back surface side electrode 6 in a dry state.
  • the electrode material for example, copper, silver, aluminum, and a mixture thereof are used.
  • an Ag-containing paste 5p which is an electrode material paste containing, for example, Ag and glass frit, is formed on the light receiving surface side grid electrode 5a and the light receiving surface side bus electrode 5b on the antireflection film 4 on the light receiving surface side of the semiconductor substrate 11.
  • the shape is applied by screen printing.
  • the Ag-containing paste 5p is dried, whereby the light-receiving surface side electrode 5 in a dry state having a comb shape is formed.
  • an Ag-containing paste 6p which is an electrode material paste containing Ag and glass frit is formed on the back-side grid electrode 6a and the back-side bus electrode 6b on the back-side high concentration impurity diffusion layer 7a on the back side of the semiconductor substrate 11.
  • the shape is applied by screen printing.
  • the Ag-containing paste 6p is dried to form the back-side electrode 6 in a dry state having a comb shape.
  • the shape of the back surface side grid electrode 6a is applied to the shape having the connecting protrusions 6t as shown in FIG. Thereby, it is not necessary to separately form only the connection protrusion 6t, and the back-side grid electrode 6a having the connection protrusion 6t can be formed without adding a process.
  • the line width of the elongated elongated portion of the back surface side grid electrode 6a is a linear pattern having the same 150 ⁇ m width as that of the back surface side high concentration impurity diffusion layer 7a, and the same 1.5 mm as that of the back surface side high concentration impurity diffusion layer 7a.
  • the back surface side grid electrode 6a having the connecting protrusions 6t is formed in a pattern arranged in parallel at intervals.
  • the Ag-containing paste 6p for forming the back surface side electrode 6 is printed on the back surface side high concentration impurity diffusion layer 7a by using an alignment mechanism. For example, a state in which infrared rays are irradiated on the back surface side of the semiconductor substrate 11 is photographed with an infrared camera. Thereby, it becomes possible to distinguish the back side high concentration impurity diffusion layer 7a and the back side low concentration impurity diffusion layer 7b. In this way, by recognizing the position of the region of the back-side high-concentration impurity diffusion layer 7a and determining the printing position of the Ag-containing paste 6p, the Ag-containing paste 6p is printed on the back-side high-concentration impurity diffusion layer 7a. It becomes possible.
  • the back surface side grid electrode 6a when the back surface side grid electrode 6a is shifted from the back surface side high concentration impurity diffusion layer 7a, the back surface side grid electrode 6a is different from the back surface side grid electrode 6a in the region where the back surface side grid electrode 6a is shifted from the region of the back surface side high concentration impurity diffusion layer 7a.
  • Contact with the back side high concentration impurity diffusion layer 7a cannot be made.
  • the electrical resistance between the back surface side grid electrode 6a and the back surface side high concentration impurity diffusion layer 7a increases, resistance loss arises, and the characteristic deterioration of the photovoltaic cell 1 is caused.
  • an increase in the area of the back-side high-concentration impurity diffusion layer 7a and an increase in the electrode width of the back-side grid electrode 6a are not effective because they cause a decrease in photoelectric conversion efficiency and an increase in cost. Further, the alignment accuracy between the back surface side grid electrode 6a and the back surface side high concentration impurity diffusion layer 7a has a limit.
  • the print mask 31 having the opening patterns 32 corresponding to the pattern of the back surface side grid electrode 6 a having the connection protrusions 6 t in parallel at the same interval is provided on the semiconductor substrate 2.
  • the Ag-containing paste 6p is printed in alignment with the back surface side of the semiconductor substrate 2 at the center position C in the surface direction of the semiconductor substrate 11 which is a specific reference position on one surface side.
  • FIG. 18 is a schematic diagram showing the configuration of the print mask 31 for printing the Ag-containing paste 6p on the pattern of the back surface side grid electrode 6a according to the embodiment of the present invention. Thereby, the back surface side grid electrode 6a in a dry state can be formed.
  • the connecting protrusion 6t causes the back surface side High-concentration impurity diffusion layer 7a and backside grid electrode 6a can be electrically connected. Thereby, the increase in resistance loss resulting from the rotational position shift of the back surface side grid electrode 6a with respect to the back surface side high concentration impurity diffusion layer 7a can be suppressed.
  • FIG. 17 is an explanatory diagram of step S110 in FIG.
  • Step S110 is a step of simultaneously baking the electrode material paste printed and dried on the light receiving surface side and the back surface side of the semiconductor substrate 11.
  • the semiconductor substrate 11 is introduced into a firing furnace, and a short-time heat treatment is performed at a peak temperature of about 600 ° C. to 900 ° C., for example, 800 ° C. for 3 seconds in an air atmosphere.
  • the resin component in the electrode material paste disappears.
  • the silver material contacts the silicon of the p-type impurity diffusion layer 3 while the glass material contained in the Ag-containing paste 5 p is melted and penetrates the antireflection film 4. Then re-solidify.
  • the light receiving surface side grid electrode 5a and the light receiving surface side bus electrode 5b are obtained, and electrical conduction between the light receiving surface side electrode 5 and the silicon of the semiconductor substrate 11 is ensured.
  • the silver material is bonded to the silicon in the back surface high concentration impurity diffusion layer 7 a. Contact and re-solidify. Thereby, the back surface side grid electrode 6a and the back surface side bus electrode 6b are obtained, and electrical conduction between the back surface side electrode 6 and the silicon of the semiconductor substrate 11 is ensured.
  • the solar battery cell 1 according to the present embodiment shown in FIGS. 1 to 3 can be manufactured.
  • the order of arrangement of the paste, which is an electrode material, on the semiconductor substrate 11 may be switched between the light receiving surface side and the back surface side.
  • the shape of the back surface side grid electrode 6a is changed. May be. That is, as shown in FIGS. 19 and 20, in the two regions of the back surface side grid electrode 6a facing each other across the center position C or the virtual line V in the extending direction of the back surface side grid electrode 6a, the back surface side grid electrode 6a.
  • the connecting protrusions 6t may be formed only on different side surfaces of the two side surfaces.
  • FIG. 19 shows a pattern of the back surface side grid electrode 6a used when the back surface side grid electrode 6a according to the embodiment of the present invention tends to cause a displacement of the formation position in a direction in which the back surface side grid electrode 6a rotates counterclockwise around the center position C. It is a schematic diagram which shows.
  • FIG. 20 shows a pattern of the back surface side grid electrode 6a used in the case where the back surface side grid electrode 6a according to the embodiment of the present invention tends to be displaced in the formation position in the direction in which the back surface side grid electrode 6a rotates clockwise around the center position C. It is a schematic diagram which shows.
  • the light receiving surface side impurity diffusion layer has a selective diffusion layer structure
  • the light receiving surface side grid electrode 5a has the same pattern as the back surface side grid electrode. It is also possible to do.
  • the light receiving surface side impurity diffusion layer 3 is constituted by the light receiving surface side high concentration impurity diffusion layer 3b and the light receiving surface side low concentration impurity diffusion layer 3c. If the impurity diffusion concentration of the light receiving surface side high concentration impurity diffusion layer 3b is the third concentration and the impurity diffusion concentration of the light receiving surface side low concentration impurity diffusion layer 3c is the fourth concentration, the fourth concentration is lower than the third concentration.
  • FIG. 21 is a schematic cross-sectional view of a relevant part of a solar battery cell in which the light-receiving surface side impurity diffusion layer according to the embodiment of the present invention has a selective diffusion layer structure.
  • the light receiving surface side high concentration impurity diffusion layer 3b has the same shape and dimensions as the light receiving surface side grid electrode 5a, and the light receiving surface side grid electrode 5a is printed on the light receiving surface side high concentration impurity diffusion layer 3b. . Also in this case, similarly to the case where the back surface side grid electrode 6a is used, even when the printing position is slightly shifted in the rotation direction when the light receiving surface side grid electrode 5a is printed, the light receiving surface side grid electrode 5a is provided.
  • the light receiving surface side high-concentration impurity diffusion layer 3b and the light receiving surface side grid electrode 5a can be electrically connected by the connecting protrusion. Thereby, it is possible to suppress an increase in resistance loss due to a rotational position shift of the light receiving surface side grid electrode 5a with respect to the light receiving surface side high concentration impurity diffusion layer 3b.
  • connection protrusion 6t protrudes in a direction perpendicular to the longitudinal direction of the back surface side grid electrode 6a.
  • connection protrusion 6t extends in the longitudinal direction of the back surface side grid electrode 6a. And may protrude in an inclined direction.
  • the back side high-concentration impurity diffusion layer 7a has a long and narrow shape that does not have a connecting protrusion.
  • the back side high-concentration impurity diffusion layer 7a has a back-side grid electrode 6a. It may be made into the shape provided with the protrusion part for a connection which has the same shape and dimension. In this case, the shape and size of the back surface side grid electrode 6a are the same as the shape and size of the back surface side high concentration impurity diffusion layer 7a.
  • the semiconductor substrate 2 is not limited to this. That is, as long as it functions as a solar cell substrate, the semiconductor substrate 2 may be an n-type polycrystalline silicon substrate. Further, a p-type silicon substrate may be used as the semiconductor substrate 2. Further, the diffusion layers formed on the light receiving surface side and the back surface side of the semiconductor substrate 2 may be appropriately determined depending on the conductivity type of the semiconductor substrate 2. Further, the impurity elements that form the diffusion layers on the light receiving surface side and the back surface side of the semiconductor substrate 2 may be selected as appropriate.
  • the back surface side grid electrode 6a includes the connecting protrusion 6t.
  • the width 7W of the back-side high-concentration impurity diffusion layer can be set to the necessary minimum, that is, the same width as the width 6aW of the back-side grid electrode.
  • the amount of the metal material used for the back surface side grid electrode 6a can be reduced by thinning the back surface side grid electrode 6a, and the back surface side grid electrode 6a and the photovoltaic cell 1 cost can be reduced. A reduction can be realized.
  • the solar battery cell 1 it is possible to reduce the cost by reducing the amount of electrode material used by thinning the back surface side grid electrode 6a, and the back surface side high concentration impurity diffusion layer.
  • a solar battery cell capable of suppressing a decrease in photoelectric conversion efficiency due to electrical connection between 7a and the back surface side grid electrode 6a is obtained.
  • the configuration described in the above embodiment shows an example of the contents of the present invention, and can be combined with another known technique, and can be combined with other configurations without departing from the gist of the present invention. It is also possible to omit or change the part.
  • 1 solar cell 2 semiconductor substrate, 3 light receiving surface side impurity diffusion layer, 3a p-type impurity diffusion layer, 4 antireflection film, 5 light receiving surface side electrode, 5a light receiving surface side grid electrode, 5b light receiving surface side bus electrode, 5p Ag-containing paste, 6 back side electrode, 6a back side grid electrode, 6aW back side grid electrode width, 6b back side bus electrode, 6p Ag containing paste, 6t connecting projection, 6tW connecting projection width, 7 Back side impurity diffusion layer, 7W, width of back side high concentration impurity diffusion layer, 7a, back side high concentration impurity diffusion layer, 7b, back side low concentration impurity diffusion layer, 8 back side insulation film, 11 semiconductor substrate, 21 oxide film, 22 Phosphorus-containing doping paste, D1 arrangement interval, D2 arrangement interval, V imaginary line.

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Abstract

Selon l'invention, une couche de dispersion d'impuretés (7) du côté de la surface arrière comporte une couche de dispersion d'impuretés à forte concentration (7a) du côté de la surface arrière de forme linéaire incluant un premier type conducteur d'un élément d'impuretés dans une première concentration et une couche de dispersion d'impuretés à faible concentration (7b) du côté de la surface arrière dans laquelle le même type conducteur d'élément d'impuretés que la couche de dispersion d'impuretés à forte concentration (7a) est inclus à une deuxième concentration qui est inférieure à la première concentration. Une électrode de réseau (6a) du côté de la surface arrière comporte une pluralité d'excroissances de connexion (6t) dépassant de la surface latérale de l'électrode de réseau (6a) du côté de la surface arrière dans la direction en intersection avec la direction d'extension de l'électrode de réseau (6a) du côté de la surface arrière et disposées de manière divisée le long de la direction d'extension de l'électrode de réseau (6a) du côté de la surface arrière. Les longueurs des excroissances de la pluralité d'excroissances de connexion (6t) depuis la surface latérale de l'électrode de réseau (6a) du côté de la surface arrière à des distances de plus en plus grandes depuis une position de référence spécifique sur un côté de surface d'un substrat semi-conducteur sont supérieure dans la direction d'extension de l'électrode de réseau (6a) de la surface arrière.
PCT/JP2015/072560 2015-08-07 2015-08-07 Élément de batterie solaire et procédé de fabrication d'élément de batterie solaire WO2017026016A1 (fr)

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109803476A (zh) * 2017-11-17 2019-05-24 核工业西南物理研究院 一种体放电等离子体发生装置
WO2019139425A1 (fr) * 2018-01-12 2019-07-18 (주)이노페이스 Masque de pochoir pour électrodes arrière de pile solaire
CN112133773A (zh) * 2020-09-22 2020-12-25 常州时创能源股份有限公司 太阳能电池片、光伏组件
WO2021032246A1 (fr) * 2019-08-16 2021-02-25 Hanwha Q Cells Gmbh Cellule solaire à base de plaquette
CN114361266A (zh) * 2020-09-28 2022-04-15 苏州阿特斯阳光电力科技有限公司 光伏组件

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005317886A (ja) * 2004-03-29 2005-11-10 Kyocera Corp 光電変換装置とこれを用いた太陽電池素子、並びに太陽電池モジュール
JP2010208317A (ja) * 2009-02-10 2010-09-24 Shin-Etsu Chemical Co Ltd スクリーン印刷方法
JP2012009578A (ja) * 2010-06-24 2012-01-12 Sharp Corp 太陽電池
JP2012502498A (ja) * 2008-09-12 2012-01-26 エルジー・ケム・リミテッド 電力損失を最少に抑えた太陽電池用前面電極及びそれを含む太陽電池
JP2012134398A (ja) * 2010-12-22 2012-07-12 ＰＶＧ Ｓｏｌｕｔｉｏｎｓ株式会社 太陽電池セルおよびその製造方法
WO2013046351A1 (fr) * 2011-09-28 2013-04-04 三洋電機株式会社 Cellule solaire et procédé de fabrication de cellule solaire
JP2013201282A (ja) * 2012-03-26 2013-10-03 Sharp Corp スクリーン、太陽電池の製造方法、および太陽電池

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4590327A (en) * 1984-09-24 1986-05-20 Energy Conversion Devices, Inc. Photovoltaic device and method
KR100989322B1 (ko) * 2009-02-05 2010-10-25 에스에스씨피 주식회사 선택적 에미터 구조를 가지는 태양 전지 기판의 제조 방법 및 태양 전지
KR101135585B1 (ko) * 2010-06-21 2012-04-17 엘지전자 주식회사 태양 전지 및 그 제조 방법
WO2012057316A1 (fr) * 2010-10-29 2012-05-03 三洋電機株式会社 Procédé de fabrication pour un module de piles solaires
CN104205351B (zh) * 2012-03-23 2016-10-12 松下知识产权经营株式会社 太阳电池
KR20140126819A (ko) 2013-04-22 2014-11-03 엘지전자 주식회사 태양 전지

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005317886A (ja) * 2004-03-29 2005-11-10 Kyocera Corp 光電変換装置とこれを用いた太陽電池素子、並びに太陽電池モジュール
JP2012502498A (ja) * 2008-09-12 2012-01-26 エルジー・ケム・リミテッド 電力損失を最少に抑えた太陽電池用前面電極及びそれを含む太陽電池
JP2010208317A (ja) * 2009-02-10 2010-09-24 Shin-Etsu Chemical Co Ltd スクリーン印刷方法
JP2012009578A (ja) * 2010-06-24 2012-01-12 Sharp Corp 太陽電池
JP2012134398A (ja) * 2010-12-22 2012-07-12 ＰＶＧ Ｓｏｌｕｔｉｏｎｓ株式会社 太陽電池セルおよびその製造方法
WO2013046351A1 (fr) * 2011-09-28 2013-04-04 三洋電機株式会社 Cellule solaire et procédé de fabrication de cellule solaire
JP2013201282A (ja) * 2012-03-26 2013-10-03 Sharp Corp スクリーン、太陽電池の製造方法、および太陽電池

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109803476A (zh) * 2017-11-17 2019-05-24 核工业西南物理研究院 一种体放电等离子体发生装置
WO2019139425A1 (fr) * 2018-01-12 2019-07-18 (주)이노페이스 Masque de pochoir pour électrodes arrière de pile solaire
WO2021032246A1 (fr) * 2019-08-16 2021-02-25 Hanwha Q Cells Gmbh Cellule solaire à base de plaquette
CN114556591A (zh) * 2019-08-16 2022-05-27 韩华Qcells有限公司 晶片太阳能电池
CN112133773A (zh) * 2020-09-22 2020-12-25 常州时创能源股份有限公司 太阳能电池片、光伏组件
CN112133773B (zh) * 2020-09-22 2022-08-09 常州时创能源股份有限公司 太阳能电池片、光伏组件
CN114361266A (zh) * 2020-09-28 2022-04-15 苏州阿特斯阳光电力科技有限公司 光伏组件
CN114361266B (zh) * 2020-09-28 2024-03-22 苏州阿特斯阳光电力科技有限公司 光伏组件

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