JP2020013868A - Back electrode type photoelectric conversion element, photoelectric conversion module, and electronic equipment - Google Patents

Abstract

To provide a back electrode type photoelectric conversion element having high photoelectric conversion efficiency irrespective of the position of a connection portion, and a highly reliable photoelectric conversion module and an electronic device including the back electrode type photoelectric conversion element.SOLUTION: A back electrode type photoelectric conversion element includes a semiconductor substrate having one surface and the other surface in a front-to-back relationship with the one surface, a first electrode provided above the one surface of the semiconductor substrate and extending in a first direction, a second electrode provided above the one surface of the semiconductor substrate, extending in a second direction orthogonal to the first direction, and electrically connected to the first electrode, and a third electrode provided above the one surface of the semiconductor substrate, extending in the first direction, and branching from the second electrode.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a back electrode type photoelectric conversion element, a photoelectric conversion module, and an electronic device.

  Wearable electronic devices (watches) that receive radio waves from positioning information satellites used in positioning systems such as GPS (Global Positioning System), obtain the time included in positioning signals, and detect the current position are proposed. Have been.

  For example, Patent Document 1 discloses a watch case, a dial, a clock module including an antenna disposed below the dial and receiving an electric wave from a position information satellite, and a clock module provided between the dial and the clock module. And a solar panel provided. According to such a wristwatch, since the dial has light transmissivity, it is possible to generate electric power necessary for the operation of the watch module by irradiating the solar panel with external light transmitted through the dial. it can.

  On the other hand, an ultra-high frequency wave is used for the radio wave transmitted from the positioning information satellite, and it is necessary to operate a high-frequency circuit in order to receive the ultra-high frequency wave. For this reason, there is a problem that the power consumption of the wristwatch increases.

  Therefore, it has been studied to increase the power consumption by increasing the area of the solar panel. However, in the case of a product such as a wristwatch where design is important, it is generally preferable that the occupied area of the solar panel with respect to the surface area of the wristwatch is small. Therefore, the application of a back contact type (back electrode type) solar cell as a solar panel having a large amount of power generation per unit area is being studied.

  Patent Document 2 discloses a single-crystal silicon type solar cell having a P-type electrode and an N-type electrode on the back surface. Since this solar cell is of a back contact type, both the P-type electrode and the N-type electrode can be provided on the back surface. For this reason, in the solar cell described in Patent Document 2, it is not necessary to provide an electrode on the surface, that is, on the light receiving surface, and a decrease in the photoelectric conversion efficiency (shadow loss) due to the shadow of the electrode can be suppressed.

  Further, as an example of such a back contact type solar cell, in the solar cell described in Patent Document 2, an interconnector is used to connect adjacent cells. In order to achieve electrical connection between the interconnector and the cell, a P-type electrode and an N-type electrode, which are extraction electrodes, are provided near two opposing sides on the back surface of the single crystal silicon substrate.

  On the other hand, the P-type electrode and the N-type electrode described in Patent Document 2 (hereinafter, also referred to as “external connection electrodes”) are provided at the ends of the single-crystal silicon substrate, respectively, as described above. ing. For this reason, there is a problem that minority carriers generated in a portion of the single crystal silicon substrate overlapping with the external connection electrode cannot be sufficiently collected. In particular, in a portion overlapping with the external connection electrode, a portion close to the end face of the single crystal silicon substrate has no room for forming a PN junction, so that most of the minority carriers disappear and the photoelectric conversion efficiency is reduced. It has become.

  Therefore, it has been studied to provide the external connection electrode in a region other than the end of the single crystal silicon substrate, for example, in the center. This creates a space for forming a PN junction around the external connection electrode, so that the disappearance of the minority carriers as described above can be reduced, and a decrease in photoelectric conversion efficiency can be prevented.

JP-A-176-176957 JP 2005-11869 A

  However, when the external connection electrode is arranged in a region closer to the center of the single crystal silicon substrate, there is a restriction on the wiring pattern of the internal connection electrode that connects the PN junction to the external connection electrode. Specifically, it is necessary to route the N-type internal connection electrode so as to avoid the P-type external connection electrode, and to route the P-type internal connection electrode so as to avoid the N-type external connection electrode. is there. For this reason, especially around the external connection electrode, there is a region where the internal connection electrode cannot be efficiently routed. Such a region causes a decrease in photoelectric conversion efficiency.

  In view of the above problems, there is a need for a means for increasing the photoelectric conversion efficiency regardless of the position of the external connection electrode.

  The present invention has been made to solve the above-described problem, and can be realized as the following application examples.

A back electrode type photoelectric conversion element according to an application example of the present invention has one surface and a semiconductor substrate having the one surface and the other surface in a front-to-back relationship.
A first electrode provided above the one surface of the semiconductor substrate and extending in a first direction;
A second electrode provided above the one surface of the semiconductor substrate, extending in a second direction orthogonal to the first direction, and electrically connected to the first electrode;
A third electrode provided above the one surface of the semiconductor substrate, extending in the first direction, and branching from the second electrode;
Having.

1 is a plan view illustrating a solar cell to which a first embodiment of a photoelectric conversion module according to the present invention is applied. FIG. 2 is an exploded perspective view of the solar cell shown in FIG. 1. FIG. 3 is a plan view illustrating an electrode surface of the photoelectric conversion element illustrated in FIG. 2. FIG. 2 is an exploded sectional view of the solar cell shown in FIG. 1. FIG. 4 is a diagram illustrating an electrode in a case where the sub-finger electrode is temporarily changed to be omitted in the photoelectric conversion device illustrated in FIG. 3, and is a diagram illustrating a conventional back electrode type photoelectric conversion device. It is a top view showing the electrode side of the cell to which the 2nd embodiment of the back electrode type photoelectric conversion element of the present invention is applied. FIG. 7 is a sectional view taken along line BB of FIG. 6. It is a top view showing the electrode side of the cell to which the 3rd embodiment of the back electrode type photoelectric conversion element of the present invention is applied. It is the elements on larger scale of FIG. It is a top view showing the electrode side of the cell to which the 4th embodiment of the back electrode type photoelectric conversion element of the present invention is applied. It is a top view showing the electrode side of the cell to which a 5th embodiment of a back electrode type photoelectric conversion element of the present invention is applied. It is a perspective view showing an electronic timepiece to which an embodiment of an electronic device of the present invention is applied. It is a perspective view showing an electronic timepiece to which an embodiment of an electronic device of the present invention is applied. FIG. 14 is a plan view of the electronic timepiece shown in FIGS. FIG. 14 is a longitudinal sectional view of the electronic timepiece shown in FIGS. It is a top view which shows the modification of the electronic timepiece which applied embodiment of the electronic device of this invention. FIG. 17 is a longitudinal sectional view of the electronic timepiece shown in FIG. 16.

  Hereinafter, a back electrode type photoelectric conversion element, a photoelectric conversion module, and an electronic device of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

(Solar cells)
<< 1st Embodiment >>
First, a solar cell to which the first embodiment of the photoelectric conversion module of the present invention is applied will be described in detail. A solar cell is a photoelectric conversion module that converts light energy into electric energy.

  FIG. 1 is a plan view illustrating a solar cell to which a first embodiment of a photoelectric conversion module according to the present invention is applied. FIG. 2 is an exploded perspective view of the solar cell shown in FIG. Note that, in this specification, a side of a light source (for example, the sun, illumination, or the like) of light incident on the solar cell is referred to as a “front” and a side opposite thereto is referred to as a “back”. Further, a direction axis extending in a direction orthogonal to the light receiving surface of the solar cell is defined as a Z axis. Further, the direction from the back side to the front side is defined as “+ Z direction”, and the opposite direction is defined as “−Z direction”.

  The solar cell 80 (photoelectric conversion module) shown in FIG. 1 is provided so as to overlap with the cell 80A (back-electrode type photoelectric conversion element) in the Z-axis direction and is electrically connected to the cell 80A. 82.

  The cell 80A has an n-type (first conductivity type) Si substrate 800. When viewed in the thickness direction (Z-axis direction), that is, when the two main surfaces having a front-to-back relationship with each other are viewed in a plan view, the Si substrate 800 has a rectangular plate-like shape in a plan view. , And the two main surfaces are each orthogonal to the Z axis. The surface (one surface) opposite to the main surface facing the light source is the electrode surface 85, and the main surface (the other surface) facing the light source is the light receiving surface 84. When a texture structure described later is provided on the light receiving surface 84, the surface excluding the texture structure is orthogonal to the Z axis.

  Two axes orthogonal to the Z axis are referred to as “X axis” and “Y axis”. The long side of the Si substrate 800 extends parallel to the X axis, and the short side of the Si substrate 800 extends parallel to the Y axis. The upward direction in FIG. 1 is defined as the “+ Y direction”, and the downward direction is defined as the “−Y direction”. In addition, the rightward direction in FIG. 1 is defined as “+ X direction”, and the leftward direction is defined as “−X direction”.

  The n-type Si substrate 800 included in the cell 80A is an example of a semiconductor substrate, and may be replaced with a compound semiconductor substrate (for example, a GaAs substrate).

  Such a semiconductor substrate may have an amorphous property, but preferably has a crystalline property. This crystallinity refers to monocrystalline or polycrystalline. By including such a semiconductor substrate having crystallinity, a solar cell 80 having higher photoelectric conversion efficiency can be obtained as compared with a case including a semiconductor substrate having amorphousness. Such a solar cell 80 allows for a smaller area if the same power is generated. Therefore, by including a semiconductor substrate having crystallinity, a solar cell 80 can be obtained in which both photoelectric conversion efficiency and miniaturization are more highly compatible.

  In particular, the semiconductor substrate preferably has single crystallinity. Thereby, the photoelectric conversion efficiency of the solar cell 80 is particularly enhanced. Therefore, it is possible to maximize compatibility between the photoelectric conversion efficiency and the design. In particular, the space saving of the solar cell 80 is achieved, so that the design of an electronic device on which the solar cell 80 is mounted can be further improved. Further, there is an advantage that the photoelectric conversion efficiency is hardly reduced even in low illuminance light such as room light.

  Note that having single crystallinity includes the case where the whole semiconductor substrate is single crystal and the case where a part thereof is polycrystalline or amorphous. In the latter case, the volume of the single crystal is preferably relatively large (for example, 90% by volume or more of the whole).

  FIG. 3 is a plan view showing the electrode surface 85 of the cell 80A shown in FIG. FIG. 4 is an exploded sectional view of the solar cell 80 shown in FIG. The cross-sectional view of the cell 80A shown in FIG. 4 is a cross-sectional view taken along line AA of FIG. FIG. 3 shows the finger electrode 804 and the bus bar electrode 805 through a passivation film 807 provided on the electrode surface 85.

  The solar cell 80 is of a back electrode type. More specifically, as shown in FIG. 4, the cell 80A has electrode pads 86 and 87 (connecting portions) provided on the electrode surface 85. Among them, the electrode pad 86 is a positive electrode, while the electrode pad 87 is a negative electrode. Therefore, electric power can be extracted from the electrode pads 86 and 87.

  In such a back electrode type, all the electrode pads 86 and 87 can be arranged on the electrode surface 85 regardless of the polarity. For this reason, the light receiving surface 84 can be maximized, and the amount of power generation can be improved with the maximization of the light receiving area. In addition, it is possible to prevent the design from being deteriorated due to the provision of the electrode pad on the light receiving surface 84 side. Therefore, the design of the solar cell 80 can be improved.

  Note that a plurality of electrode pads 86 and electrode pads 87 may be provided in the cell 80A.

((Wiring board))
The solar cell 80 shown in FIG. 4 includes the cell 80A and the wiring board 82 as described above.

  The wiring board 82 includes an insulating substrate 821 and a conductive film 822 provided thereon.

  The wiring board 82 is provided so as to overlap the cell 80A, as shown in FIGS. Such a wiring substrate 82 includes an insulating substrate 821, a conductive film 822 provided thereon, and an insulating film 823 having an opening 824 provided in a portion overlapping with the conductive film 822.

  Note that “the wiring board 82 overlaps the cell 80A” refers to a state where at least a part of the cell 80A overlaps with the wiring board 82 in a plan view of the wiring board 82.

  Examples of the insulating substrate 821 include various resin substrates such as a polyimide substrate and a polyethylene terephthalate substrate.

  As a constituent material of the conductive film 822, for example, copper or a copper alloy, aluminum or an aluminum alloy, silver or a silver alloy, or the like can be given.

  Examples of a constituent material of the insulating film 823 include various resin materials such as a polyimide resin and a polyethylene terephthalate resin.

Further, the insulating substrate 821 and the insulating film 823 are bonded to each other through an adhesive layer 825.
Examples of the constituent material of the adhesive layer 825 include an epoxy-based adhesive, a silicone-based adhesive, an olefin-based adhesive, and an acrylic-based adhesive.

  The thickness of the wiring board 82 is not particularly limited, but is preferably 50 μm or more and 500 μm or less, and more preferably 100 μm or more and 300 μm or less. By setting the thickness of the wiring board 82 within the above range, appropriate flexibility is given to the wiring board 82.

((cell))
As shown in FIG. 3 or FIG. 4, cell 80A is connected to Si substrate 800, p + impurity region 801 and n + impurity region 802 formed on Si substrate 800, and p + impurity region 801 and n + impurity region 802. Finger electrode 804, a bus bar electrode 805 connected to the finger electrode 804, an electrode pad 86 (positive connection part) connected to the p + impurity region 801 via the finger electrode 804, and a finger electrode 804 And an electrode pad 87 (a connection portion of a negative electrode) connected to the n + impurity region 802. In FIG. 4, for convenience of illustration, only the electrode pad 86 is illustrated, and the illustration of the electrode pad 87 is omitted.

-Si substrate-
As the Si substrate 800, for example, a Si (100) substrate or the like is used. The crystal plane of Si substrate 800 is not particularly limited, and may be a crystal plane other than the Si (100) plane.

The impurity element concentration other than the main constituent elements of the Si substrate 800 (semiconductor substrate) is preferably as low as possible, but is more preferably 1 × 10 ¹¹ [atoms / cm ² ] or less, and more preferably 1 × 10 ¹⁰ [atoms / cm ² ]. / Cm ² ] or less. When the impurity element concentration is within the above range, the effect of impurities of the Si substrate 800 on photoelectric conversion can be sufficiently suppressed. This makes it possible to realize a solar cell 80 that can generate sufficient power even with a small area. Further, there is an advantage that the photoelectric conversion efficiency is hardly reduced even with low illuminance light such as room light.

  Note that the impurity element concentration of the Si substrate 800 can be measured by, for example, an ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) method.

  Further, a part of the finger electrode 804 connected to the p + impurity region 801 is exposed from a passivation film 807 described later, and constitutes the electrode pad 86 described above (see FIG. 3). On the other hand, a part of the finger electrode 804 connected to the n + impurity region 802 is exposed from a later-described passivation film 807 to form the above-described electrode pad 87 (see FIG. 3).

  In addition, as shown in FIG. 4, the electrode pad 86 is connected to the wiring board 82 via the conductive connection portion 83. Similarly, the electrode pad 87 is connected to the wiring board 82 via a conductive connection (not shown).

  Examples of the conductive connection portion 83 include a conductive paste, a conductive sheet, a metal material, a solder, a brazing material, and the like.

  A texture structure is formed on the light receiving surface 84 of the Si substrate 800 as necessary. The texture structure refers to, for example, an irregular shape having an arbitrary shape. Specifically, for example, it is configured by a large number of pyramid-shaped protrusions formed on the light receiving surface 84. By providing such a texture structure, reflection of external light on the light receiving surface 84 can be suppressed, and the amount of light incident on the Si substrate 800 can be increased. Further, external light incident from the light receiving surface 84 can be confined inside the Si substrate 800, and the photoelectric conversion efficiency can be increased.

  When the Si substrate 800 is, for example, a substrate having a Si (100) surface as a main surface, a pyramid-shaped protrusion having an Si (111) surface as an inclined surface is suitably used as a texture structure.

  The thickness of the Si substrate 800 is not particularly limited, but is preferably 50 μm or more and 500 μm or less, and more preferably 100 μm or more and 300 μm or less. Thereby, it is possible to achieve both the photoelectric conversion efficiency and the mechanical characteristics of the solar cell 80.

  The planar shape of the Si substrate 800 is not limited to the above, and may be any shape, for example, a square such as a square or a rhombus, a hexagon, a polygon such as an octagon, a perfect circle, an ellipse, or an ellipse. It may be circular, fan-shaped, or the like.

On the other hand, the p + impurity region 801 is a region containing a relatively high concentration of p-type impurities such as boron ions and aluminum ions. The n + impurity region 802 is a region containing an n-type impurity such as phosphorus ions or arsenic ions at a relatively high concentration. The concentration of the p-type impurity in p + impurity region 801 and the concentration of the n-type impurity in n + impurity region 802 are not particularly limited, but are preferably 1 × 10 ¹⁸ [atoms / cm ² ] or more, and preferably 1 × 10 ¹⁸ [atoms / cm ² ]. More preferably, it is 10 ¹⁹ [atoms / cm ² ] or more.

-Passivation film-
Further, as shown in FIG. 4, the solar cell 80 includes a passivation film 817 provided on the light receiving surface 84. By providing such a passivation film 817, it is possible to prevent minority carriers generated by light reception from disappearing on the light receiving surface 84.

  Examples of a constituent material of the passivation film 817 include an inorganic material and an organic material. Among them, examples of the inorganic material include silicon compounds such as silicon oxide, silicon nitride, and silicon oxynitride; metal oxides such as niobium oxide, titanium oxide, tantalum oxide, aluminum oxide, zirconium oxide, and lanthanum oxide; Examples include fluorides such as magnesium fluoride, calcium fluoride, barium fluoride, lithium fluoride, sodium fluoride, and lanthanum fluoride. Examples of the organic material include various resin materials. As a constituent material of the passivation film 817, a composite material containing one or more of these materials is used.

  Further, the passivation film 817 has light transmittance. Therefore, the passivation film 817 also functions as an anti-reflection film by appropriately adjusting the refractive index. By adding such a function as an anti-reflection film, the amount of light incident on the Si substrate 800 from the light receiving surface 84 can be increased, and the photoelectric conversion efficiency can be increased.

  On the other hand, the cell 80A includes a passivation film 807 provided on the electrode surface 85, as shown in FIG. By providing such a passivation film 807, each part can be insulated, and the minority carriers generated by light reception can be suppressed from disappearing on the electrode surface 85.

  Examples of a constituent material of the passivation film 807 include silicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide.

-Electrodes and electrode pads (connections)-
As shown in FIGS. 3 and 4, the cell 80A includes an n-type finger electrode 804n provided so as to overlap an n + impurity region 802 (first conductivity type impurity region) in the thickness direction of the Si substrate 800; An n + contact 811n for electrically connecting the region 802 and the n-type finger electrode 804n. In FIG. 3, dots are respectively attached to the n + contact 811n and the n-type finger electrode 804n for convenience of illustration.

  Further, as shown in FIGS. 3 and 4, the cell 80A includes a p-type finger electrode 804p provided so as to overlap with the p + impurity region 801 (second conductivity type impurity region) in the thickness direction of the Si substrate 800; a p + contact 811p for electrically connecting between the p + impurity region 801 and the p-type finger electrode 804p. In FIG. 3, the p + contact 811p and the p-type finger electrode 804p are shaded for convenience of illustration.

  As shown in FIG. 3, a plurality of p + contacts 811p are provided for one p-type finger electrode 804p. Accordingly, a plurality of p + impurity regions 801 shown in FIG. 4 are provided for one p-type finger electrode 804p. Thereby, holes (carriers) generated by light reception can be efficiently taken out.

  Similarly, as shown in FIG. 3, a plurality of n + contacts 811n are provided for one n-type finger electrode 804n. Accordingly, a plurality of n + impurity regions 802 shown in FIG. 4 are provided for one n-type finger electrode 804n. Thereby, electrons (carriers) generated by light reception can be efficiently extracted.

  The constituent materials of the p + contact 811p and the n + contact 811n are appropriately selected, for example, from the same as the constituent material of the finger electrode 804 described later.

  In the Si substrate 800 shown in FIG. 3, the electrode surface 85 has a rectangular shape. In this specification and each of the drawings, a direction axis parallel to the long axis of the Si substrate 800 is defined as an X axis, and a direction axis parallel to the short axis of the Si substrate 800 is defined as a Y axis. The direction in which the X axis extends is referred to as the X axis direction (first direction), and the direction in which the Y axis extends is referred to as the Y axis direction (second direction orthogonal to the first direction).

  The cell 80A shown in FIG. 3 includes a plurality of p-type finger electrodes 804p. These p-type finger electrodes 804p extend along the Y-axis direction and are arranged in the X-axis direction.

  Further, the cell 80A shown in FIG. 3 includes one p-type busbar electrode 805p. The p-type busbar electrode 805p extends along the X-axis direction at the outer edge on the −Y side. The plurality of p-type finger electrodes 804p are electrically connected to each other via one p-type bus bar electrode 805p.

  On the other hand, the cell 80A shown in FIG. 3 includes a plurality of n-type finger electrodes 804n. These n-type finger electrodes 804n extend along the Y-axis direction and are arranged in the X-axis direction.

  The cell 80A shown in FIG. 3 includes one n-type bus bar electrode 805n. The n-type bus bar electrode 805n extends along the X-axis direction at the outer edge on the + Y side. The plurality of n-type finger electrodes 804n are electrically connected to each other via one n-type bus bar electrode 805n.

  A plurality of p-type finger electrodes 804p and one p-type bus bar electrode 805p as described above constitute a so-called comb-shaped p-type electrode. A plurality of n-type finger electrodes 804n and one n-type busbar electrode 805n form a comb-shaped n-type electrode. Then, the p-type electrode and the n-type electrode are arranged so as to mesh with each other.

  Note that the above-mentioned finger electrode 804 indicates both the p-type finger electrode 804p and the n-type finger electrode 804n.

  The above-described bus bar electrode 805 indicates both the p-type bus bar electrode 805p and the n-type bus bar electrode 805n.

  As shown in FIGS. 3 and 4, the p-type finger electrode 804p, the n-type finger electrode 804n, the p-type busbar electrode 805p, and the n-type busbar electrode 805n are covered with a passivation film 807, respectively. This protects these electrodes from the external environment.

・ Electrode pad (connection part)
On the other hand, a via hole is provided in a part of the passivation film 807, and a part of the p-type finger electrode 804p and a part of the n-type finger electrode 804n are exposed. Of these, the exposed surface of the p-type finger electrode 804p becomes the above-mentioned electrode pad 86 (the connection part of the positive electrode), and the exposed surface of the n-type finger electrode 804n becomes the above-mentioned electrode pad 87 (the connection part of the negative electrode). The electrode pads 86 and 87 may include a stud bump provided on the exposed surface as needed.

  In FIG. 3, p-type finger electrodes 804p and n-type finger electrodes 804n are alternately arranged in the X-axis direction.

  Further, on both sides of the electrode pads 86 and 87, the p-type finger electrode 804p and the n-type finger electrode 804n face each other across the electrode pads 86 and 87.

The area of one of the electrode pads 86 and 87 is appropriately set according to the size of the Si substrate 800, but is preferably 0.05 mm ² or more and 5 mm ² or less, and is 0.1 mm ² or more and 3 mm ² or less. Is more preferable. Thus, while sufficiently reducing the connection resistance and improving the connection strength, the collection loss of the minority carriers caused by providing the electrode pads 86 and 87 can be sufficiently suppressed.

  Note that the arrangement of the electrode pads 86 and 87 is not limited to the illustrated one, and may be at the center of the Si substrate 800 or at the outer edge.

  Also, the shape of the electrode pads 86 and 87 is not particularly limited, and may be any shape. As an example, the shape of each of the electrode pads 86 and 87 shown in FIG. 3 is a square, but may be a circle such as a perfect circle, an ellipse, or an ellipse, and may be a rectangle, a triangle, a hexagon, or an octagon. It may be a simple polygon or any other shape.

  Further, the electrode pad 86 and the electrode pad 87 preferably have the same shape, but may have different shapes.

  Further, in the present embodiment, the p + contact 811p and the n + contact 811n are arranged in the portion where the electrode pads 86 and 87 are provided so as not to overlap each other in plan view (see FIG. 3).

  That is, the cell 80A is provided on the n-type (first conductivity type) Si substrate 800 (semiconductor substrate) and the electrode surface 85 of the Si substrate 800, and is electrically connected to the bus bar electrode 805 (first electrode). It has ap + impurity region 801 (second conductivity type impurity region) and an n + impurity region 802 (first conductivity type impurity region), and when viewed in the thickness direction of Si substrate 800, electrode pad 86 (connection portion) Are arranged so as to deviate from n + impurity region 802 (first conductivity type impurity region) and p + impurity region 801 (second conductivity type impurity region). The electrode pad 86 is naturally arranged so as to be shifted from the p + contact 811p and the n + contact 811n.

  Similarly, when viewed in the thickness direction of Si substrate 800, electrode pad 87 (connection portion) is arranged so as to be shifted from p + impurity region 801 and n + impurity region 802. Thus, the electrode pad 87 is naturally arranged so as to be shifted from the p + contact 811p and the n + contact 811n.

  Thus, for example, after the conductive connection portion 83 is bonded to the electrode pads 86 and 87, even if the bonding portion is broken, it is possible to prevent the p + impurity region 801 and the n + impurity region 802 from being damaged. it can. Therefore, a more reliable cell 80A can be obtained. Note that, in this specification, “displaced” refers to a state in which there are no overlapping portions in plan view.

  Further, with the above arrangement, the electrode pads 86 and 87 are not affected by the p + impurity region 801 or the n + impurity region 802 in the shape such as flatness. Therefore, the electrode pads 86 and 87 having high flatness and hardly causing a contact failure can be obtained.

  In this embodiment, as shown in FIG. 3, the p + contact 811p and the n + contact 811n are arranged so as to surround the electrode pads 86 and 87 (connection portions). As described above, p + contact 811p is provided corresponding to p + impurity region 801 (second conductivity type impurity region), and n + contact 811n corresponds to n + impurity region 802 (first conductivity type impurity region). It is provided. Therefore, p + impurity region 801 and n + impurity region 802 are arranged to surround electrode pads 86 and 87 (connection portions). Since at least one of p + impurity region 801 and n + impurity region 802 is arranged at such a position, p + impurity region 801 and n + impurity region 802 are not provided on electrode pads 86 and 87 as described above. Even in this case, minority carriers generated on the Si substrate 800 can be efficiently collected. That is, in the portion of the Si substrate 800 that overlaps the electrode pads 86 and 87, the p + impurity region 801 is not provided, so that minority carriers generated by light reception cannot be collected efficiently. Therefore, by providing the p + impurity region 801 so as to surround the electrode pads 86 and 87, it becomes possible to collect the minority carriers while minimizing the disappearance of the minority carriers, regardless of the moving direction of the minority carriers. Therefore, it is possible to minimize a decrease in photoelectric conversion efficiency due to the provision of the electrode pads 86 and 87.

  Note that the arrangement of the electrode pads 86 and 87 is not necessarily limited. For example, the electrode pads 86 and 87 may be in plan view as any of the p + impurity region 801, the n + impurity region 802, the p + contact 811p, and the n + contact 811n. May overlap.

-Finger electrodes A plurality of finger electrodes 804 are provided in the cell 80A. For this reason, these finger electrodes 804 are arranged along the X-axis direction. In other words, the arrangement axis of the finger electrodes 804 is parallel to the long axis of the Si substrate 800. By arranging in this manner, the shape and area of each finger electrode 804 can be made uniform, and the structure of the cell 80A can be made uniform. As a result, deformation such as warpage in the cell 80A hardly occurs. In addition, the finger electrodes 804 can be spread over the Si substrate 800 as closely as possible. Thus, the finger electrode 804 also functions as a reflection film on the electrode surface 85 side of the Si substrate 800 for reflecting light incident from the light receiving surface 84. That is, since the finger electrodes 804 are laid without gaps, light incident from the light receiving surface 84 and transmitted through the Si substrate 800 can be reflected at the finger electrodes 804 with a higher probability. Thereby, the amount of light contributing to the photoelectric conversion can be increased, and the photoelectric conversion efficiency can be improved.

  Further, at least the finger electrodes 804 adjacent to each other are not particularly limited, but preferably have the same shape and the same area. As a result, the structure of the cell 80A is further uniformed.

  Note that the same shape, the same area, and the parallel are concepts that allow an error that occurs during manufacturing.

  In addition, when a plurality of finger electrodes 804 are arranged, it is preferable that the p-type finger electrodes 804p and the n-type finger electrodes 804n are alternately arranged. However, the arrangement is not limited to such an arrangement pattern. All may be different arrangement patterns.

  The width of the finger electrode 804 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less. This optimizes the pitch between the contacts provided corresponding to each finger electrode 804 and the pitch between the impurity regions, thereby improving the efficiency of taking out minority carriers generated by light reception. As a result, a cell 80A having a particularly high photoelectric conversion efficiency is obtained.

  On the other hand, the distance between the finger electrodes 804 is preferably 1 μm or more and 50 μm or less, and more preferably 3 μm or more and 30 μm or less. Accordingly, the area occupied by the finger electrodes 804 can be sufficiently increased while the insulation between the finger electrodes 804 is achieved.

Bus Bar Electrode On the other hand, as shown in FIG. 3, the cell 80A includes a p-type bus bar electrode 805p provided to connect a plurality of p-type finger electrodes 804p to each other. Similarly, as shown in FIG. 3, the cell 80A includes an n-type busbar electrode 805n provided to connect a plurality of n-type finger electrodes 804n to each other. In FIG. 3, for convenience of illustration, the p-type busbar electrode 805p is hatched, and the n-type busbar electrode 805n is dotted.

  The p-type busbar electrode 805p is provided so as to overlap the p + impurity region 801 and the p + contact 811p in the thickness direction of the Si substrate 800, similarly to the p-type finger electrode 804p. Similarly, n-type busbar electrode 805n is provided so as to overlap n + impurity region 802 and n + contact 811n in the thickness direction of Si substrate 800, similarly to n-type finger electrode 804n.

  Here, the extending direction of the bus bar electrode 805 crosses the extending direction of the finger electrode 804, as shown in FIG. That is, as described above, the finger electrode 804 extends along the Y-axis direction, whereas the bus bar electrode 805 extends along the X-axis direction. Therefore, the finger electrode 804 and the bus bar electrode 805 are substantially orthogonal.

  The intersection angle between the finger electrode 804 and the bus bar electrode 805 is 90 °, but may include an error generated at the time of manufacturing.

  As a constituent material of the finger electrode 804 and the bus bar electrode 805, for example, a simple substance or an alloy of a metal such as aluminum, titanium, and copper can be used.

-Sub-finger electrode Further, as shown in FIG. 3, the cell 80A includes a plurality of p-type sub-finger electrodes 806p branched from the p-type finger electrode 804p. Similarly, as shown in FIG. 3, the cell 80A includes a plurality of n-type sub-finger electrodes 806n branched from the n-type finger electrodes 804n. In FIG. 3, for convenience of illustration, the p-type sub-finger electrode 806p is hatched, and the n-type sub-finger electrode 806n is dotted.

  The p-type sub-finger electrode 806p is provided so as to overlap the p + impurity region 801 and the p + contact 811p in the thickness direction of the Si substrate 800, similarly to the p-type finger electrode 804p. Similarly, n-type sub-finger electrode 806n is provided so as to overlap n + impurity region 802 and n + contact 811n in the thickness direction of Si substrate 800, similarly to n-type finger electrode 804n.

  In the following description, both the p-type sub-finger electrode 806p and the n-type sub-finger electrode 806n are referred to as a sub-finger electrode 806.

  The extending direction of the sub-finger electrode 806 crosses the extending direction of the finger electrode 804, as shown in FIG. Then, as described above, the sub-finger electrode 806 branches off from the finger electrode 804. Note that “branched” means that the finger electrode 804 and the sub-finger electrode 806 are provided on the same plane (the positions of the arrangement planes in the Z-axis direction are the same). In addition, it refers to a structure in which a sub-finger electrode 806 extends along the X-axis direction from the end or the middle of the finger electrode 804 extending in the Y-axis direction.

  The plurality of p-type sub-finger electrodes 806p and the p-type finger electrode 804p as a branching source constitute a so-called comb-shaped p-type electrode. Further, a plurality of n-type sub-finger electrodes 806n and an n-type finger electrode 804n that is a branch source thereof constitute a comb-shaped n-type electrode. Then, the p-type electrode and the n-type electrode are arranged so as to mesh with each other.

  By providing such a sub-finger electrode 806, the p + impurity region 801 and the n + impurity region 802 can be arranged without gaps regardless of the positions of the electrode pads 86 and 87. Accordingly, for example, even when electrode pads 86 and 87 are arranged inside (central part) the outer edge of Si substrate 800, p + impurity region 801 and p + impurity region 801 surround electrode pads 86 and 87. It becomes possible to arrange the n + impurity region 802. That is, by using the sub-finger electrode 806, electrical connection can also be achieved with the p + impurity region 801 and the n + impurity region 802 arranged at such positions. As a result, disappearance of minority carriers generated by light reception can be reduced as much as possible, and photoelectric conversion efficiency can be improved.

  Here, FIG. 5 is a diagram showing an electrode in a case where the sub-finger electrode 806 is temporarily changed to be omitted in the cell 80A shown in FIG. 3, that is, a diagram showing a conventional back electrode type photoelectric conversion element.

  In the cell 80A 'shown in FIG. 5, the sub-finger electrode 806 branched from the finger electrode 804 is not provided. Therefore, in the conventional back electrode type photoelectric conversion element, for example, as shown as electrode unreachable regions 809p and 809n in FIG. 5, a region surrounded by only the finger electrode 804 of one polarity or the bus bar electrode 805 occurs. . More specifically, the electrode unreachable region 809p shown in FIG. 5 is surrounded by an n-type finger electrode 804n, an n-type bus bar electrode 805n, and an electrode pad 87. Therefore, the p-type finger electrode 804p cannot be routed in the electrode unreachable region 809p, and the minority carriers generated in the electrode unreachable region 809p cannot be collected efficiently. As a result, there is a problem that the photoelectric conversion efficiency cannot be improved. The electrode unreachable region 809n shown in FIG. 5 is surrounded by a p-type finger electrode 804p, a p-type bus bar electrode 805p, and an electrode pad 86. Therefore, the n-type finger electrode 804n cannot reach the electrode unreachable region 809n, and the majority carriers in this region cannot be efficiently collected. For the reasons described above, the conventional back electrode type photoelectric conversion element has a problem that an electrode cannot be routed depending on the position of the electrode pad (connection portion), and the photoelectric conversion efficiency cannot be increased. Was.

  On the other hand, in the cell 80A shown in FIG. 3, by providing the sub-finger electrode 806, the electrode can be routed to the electrode unreachable regions 809p and 809n shown in FIG. Therefore, minority carriers generated in the electrode unreachable region 809p shown in FIG. 5 can be efficiently collected, and the photoelectric conversion efficiency can be increased.

  Moreover, in the conventional back electrode type photoelectric conversion element, in order to solve the above-mentioned problem, an electrode pad (connection part) may be arranged at an outer edge of the Si substrate. With such an arrangement, the electrode unreachable regions 809p and 809n are not generated, so that a decrease in photoelectric conversion efficiency can be prevented. On the other hand, when the arrangement of the electrode pads is at the outer edge of the Si substrate, the point for fixing the Si substrate is also biased toward the outer edge. For this reason, conventionally, there is a problem that even if an attempt is made to fix the cell by connecting the conductive connecting portion to the electrode pad, the fixing of the cell becomes unstable.

  Therefore, it is conceivable to change the arrangement of the electrode pads to the center of the Si substrate. In this case, however, the problem that the above-mentioned electrode unreachable regions 809p and 809n are created is inevitable.

  On the other hand, by providing the sub-finger electrode 806, even when the electrode pads 86 and 87 are arranged at the center of the Si substrate 800, a region surrounded by electrodes of the same polarity, that is, an electrode Regions 809p and 809n do not occur. Therefore, in the present embodiment, it is possible to increase the photoelectric conversion efficiency regardless of the positions of the electrode pads 86 and 87. As a result, both the effect of stably fixing the cell 80A by connecting the conductive connection portion 83 to the electrode pads 86 and 87 and the effect of increasing the photoelectric conversion efficiency of the cell 80A can be obtained.

  Note that the plurality of sub-finger electrodes 806 shown in FIG. 3 are arranged along the Y-axis direction. For this reason, the sub-finger electrode 806 can be routed to the conventional electrode unreachable regions 809p and 809n without any gap. As a result, the collection efficiency of minority carriers is increased, and the function as a reflection film that reflects light incident from the light receiving surface 84 is also improved.

  Further, the sub-finger electrode 806 does not need to be branched from all the finger electrodes 804, and the cell 80A may have a finger electrode 804 where the sub-finger electrode 806 is not branched. The length, width, and interval of the plurality of sub-finger electrodes 806 may be the same or different.

  As described above, the cell 80A, which is a back electrode type photoelectric conversion element, has an n-type (first conductivity type) Si substrate 800 (semiconductor substrate) and a p-type (second conductivity type different from the first conductivity type). A p + impurity region 801 (second conductivity type impurity region) and an n + impurity region 802 (first conductivity type impurity region) having n-type and an electrode surface 85 which is one surface of the Si substrate 800. A bus bar electrode 805 (first electrode) extending in the X-axis direction (first direction) and a Y-axis direction (second direction) provided above the electrode surface 85 of the Si substrate 800 and orthogonal to the X-axis direction. A finger electrode 804 (second electrode) extending and electrically connected to the bus bar electrode 805; and a finger electrode 804 provided above the electrode surface 85 of the Si substrate 800, extending in the X-axis direction, and extending from the finger electrode 804. Branching subfinger A pole 806 (third electrode), a.

  According to such a cell 80A, the photoelectric conversion efficiency can be increased regardless of the positions of the electrode pads 86 and 87. Therefore, for example, the solar cell 80 with high photoelectric conversion efficiency can be realized while the cell 80A is stably fixed by disposing the electrode pads 86 and 87 at the center of the Si substrate 800.

  In this embodiment, as shown in FIG. 3, the finger electrode 804 (second electrode) branches off from the bus bar electrode 805 (first electrode). Thus, in the present embodiment, the bus bar electrode 805, the finger electrode 804, and the sub-finger electrode 806 are all arranged on the same plane. For this reason, the structure of the cell 80A is simplified, and the manufacturing efficiency is easily increased.

  Further, the solar cell 80 (photoelectric conversion module) includes such a cell 80A (a back electrode type photoelectric conversion element), a wiring substrate 82 provided so as to overlap the cell 80A, and an electrode pad 86 of the cell 80A. And a conductive connecting portion 83 for electrically connecting the conductive film 87 to the conductive film 822 of the wiring board 82. Therefore, in the solar cell 80, the cell 80A is stably fixed to the wiring substrate 82, the reliability is high, and the photoelectric conversion efficiency is high.

  Moreover, in the solar cell 80, at least a part of the electrode surface 85 of the cell 80A is covered by the wiring substrate 82, so that the electrode surface 85 is protected. For this reason, attachment of foreign matter to the electrode surface 85 and application of external force are suppressed. As a result, the reliability of the electrode surface 85 can be ensured.

  In other words, when the light receiving surface 84 is viewed in a plan view, the conductive connection portion 83 is preferably hidden behind the cell 80A (overlaps with the cell 80A). Thereby, in addition to the effect of ensuring the above-described reliability, it is possible to improve the aesthetic appearance of the solar cell 80 due to the invisible conductive connection portion 83.

  The conductive connection portion 83 connects the cell 80A and the wiring board 82 not only electrically but also mechanically. Therefore, by optimizing the mechanical characteristics of the conductive connection portion 83, the concentration of the stress in the cell 80A described above can be reduced.

  Specifically, the Young's modulus of the conductive connection portion 83 is preferably 0.5 GPa or more and 15 GPa or less, more preferably 1 GPa or more and 10 GPa or less, and even more preferably 1.5 GPa or more and 6.5 GPa or less. preferable. By setting the Young's modulus of the conductive connection portion 83 within the above range, distortion and the like can be absorbed in the conductive connection portion 83 while securing the adhesive strength required for the conductive connection portion 83. Therefore, it is possible to achieve both the reliability of mechanical connection based on high mechanical characteristics and the characteristic of reducing the concentration of stress generated in the cell 80A.

  When the Young's modulus of the conductive connection portion 83 is lower than the lower limit, the mechanical properties of the conductive connection portion 83 are reduced, and thus the required adhesive strength may not be satisfied depending on the specifications of the cell 80A. . On the other hand, if the Young's modulus of the conductive connecting portion 83 exceeds the upper limit, the deformability of the conductive connecting portion 83 is reduced. Therefore, depending on the specification of the cell 80A, the conductive connecting portion 83 can sufficiently absorb the distortion of the cell 80A. Therefore, there is a possibility that a defect such as warpage may occur in the cell 80A.

  The Young's modulus of the conductive connection portion 83 is measured at 25 ° C. by a dynamic viscoelasticity measuring device (DMA), for example.

  Further, from the viewpoint of the Young's modulus described above, a conductive adhesive containing a resin material is particularly preferably used for the conductive connection portion 83.

  Examples of the resin material included in the conductive adhesive include an epoxy resin, a urethane resin, a silicone resin, an acrylic resin, and the like, and one or more of these are used as a mixture. .

<< 2nd Embodiment >>
Next, a cell to which the second embodiment of the back electrode type photoelectric conversion element of the present invention is applied will be described in detail.

  FIG. 6 is a plan view showing an electrode surface of a cell to which the second embodiment of the back electrode type photoelectric conversion element of the present invention is applied. FIG. 7 is a sectional view taken along line BB of FIG. Note that FIG. 6 illustrates the finger electrode 804 and the sub-finger electrode 806 through the passivation film 807 and the bus bar electrode 805 provided on the electrode surface 85. In FIG. 6, only the outline of the bus bar electrode 805 is shown by a dashed line.

  Hereinafter, the second embodiment will be described, but in the following description, differences from the first embodiment will be mainly described, and description of similar items will be omitted. In FIGS. 6 and 7, the same components as those in the first embodiment described above are denoted by the same reference numerals.

  In the cell 80A according to the first embodiment described above, the bus bar electrode 805 and the finger electrode 804 are arranged on the same surface, whereas in the cell 80B according to the second embodiment, the bus bar electrode 805 and the finger electrode 804 are arranged. 804 are arranged on different planes, that is, on planes whose positions in the Z-axis direction are different from each other. Other configurations are the same as those of the cell 80A according to the first embodiment.

  Thus, in the cell 80B according to the present embodiment, the bus bar electrode 805 is provided so as to overlap the finger electrode 804 in the thickness direction of the Si substrate 800. Specifically, a p-type busbar electrode 805p extending in the X-axis direction is provided on the −Y side of the electrode surface 85 of the Si substrate 800. On the + Y side of the electrode surface 85 of the Si substrate 800, an n-type busbar electrode 805n extending in the X-axis direction is provided.

  These busbar electrodes 805 are provided so as to straddle the plurality of finger electrodes 804 and the plurality of sub-finger electrodes 806. The bus bar electrode 805 is insulated from the finger electrode 804 and the sub-finger electrode 806 via a passivation film 807.

  According to such a structure, of the electrode surface 85, the area secured for arranging the bus bar electrode 805 in the first embodiment can be diverted for arranging the finger electrode 804 and the sub-finger electrode 806. Can be. Therefore, the p + impurity regions 801 can be arranged at a higher density, and the photoelectric conversion efficiency can be further increased.

Also in the present embodiment, when the Si substrate 800 is viewed from the thickness direction, the extending direction of the bus bar electrode 805 and the extending direction of the finger electrode 804 are orthogonal to each other. The sub-finger electrode 806 is branched from the finger electrode 804.
In the second embodiment as described above, the same effects as in the first embodiment can be obtained.

  Further, as described above, in the present embodiment, the electrode pads 86 and 87 (provided on the electrode surface 85 (one surface) of the Si substrate 800 and electrically connected to the bus bar electrode 805 (first electrode)). Connection part). That is, the bus bar electrode 805 is covered with the passivation film 807 as shown in FIG. Then, a part of the bus bar electrode 805 is exposed in the −Z direction by an opening provided in a part of the passivation film 807. These exposed portions constitute the electrode pads 86 and 87.

  These electrode pads 86 and 87 are arranged inside the outer edge of the Si substrate 800, that is, at the center. Thus, when the conductive connection portion 83 is connected to the electrode pads 86 and 87 to fix the cell 80B, the cell 80B can be fixed more stably.

  The “outer edge of the Si substrate 800” refers to a range of 10% of the length of the short axis of the Si substrate 800 from the outer edge of the Si substrate 800. The “length of the short axis of the Si substrate 800” refers to the maximum length that the Si substrate 800 can have.

  Further, in the present embodiment, as described above, the passivation film 807 (insulating layer) provided between the bus bar electrode 805 (first electrode) and the finger electrode 804 (second electrode) is further provided. . The cell 80B according to the present embodiment includes a p-type through wiring 814p that penetrates the passivation film 807 in the thickness direction and electrically connects the p-type busbar electrode 805p and the p-type finger electrode 804p, and an n-type busbar. An n-type through wiring 814n for electrically connecting the electrode 805n and the n-type finger electrode 804n is further provided.

  According to such a structure, a sufficiently large width of the bus bar electrode 805 can be ensured regardless of the arrangement of the finger electrodes 804. Therefore, the conductivity of the bus bar electrode 805 can be further increased, and photoelectric conversion loss due to electric resistance can be suppressed. In addition, since the bus bar electrode 805 functions as a reflection film that reflects light incident from the light receiving surface 84, the photoelectric conversion efficiency can be further improved.

<< 3rd Embodiment >>
Next, a cell to which the third embodiment of the back electrode type photoelectric conversion element of the present invention is applied will be described in detail.

  FIG. 8 is a plan view showing an electrode surface of a cell to which the third embodiment of the back electrode type photoelectric conversion element of the present invention is applied. In FIG. 8, the bus bar electrode 805, the finger electrode 804, and the sub-finger electrode 806 are shown as being seen through the passivation film 807 provided on the electrode surface 85.

  Hereinafter, the third embodiment will be described, but the following description focuses on differences from the first embodiment, and a description of the same items will be omitted. In FIG. 8, the same components as those in the above-described first embodiment are denoted by the same reference numerals.

  In the cell 80A according to the first embodiment described above, the p-type busbar electrode 805p is provided on the −Y side outer edge of the electrode surface 85 of the Si substrate 800, and the n-type busbar electrode 805n is provided on the + Y side outer edge. On the other hand, in the cell 80C according to the third embodiment, the p-type bus bar electrode 805p is provided along the outer edge of the Si substrate 800.

  That is, in the cell 80C according to the present embodiment, the Si substrate 800 (semiconductor substrate) is an n-type (first conductivity type), and the electrode surface 85 of the Si substrate 800 has an n + impurity region 802 (first conductivity type impurity region). ) And a p + impurity region 801 (second conductivity type impurity region).

  As described above, the bus bar electrode 805 (first electrode) is a p-type bus bar electrode 805p (second electrode) electrically connected to the p + impurity region 801 (see FIG. 4) which is the second conductivity type impurity region. And an n-type busbar electrode 805n (first first electrode) electrically connected to an n + impurity region 802 (see FIG. 4) that is a first conductivity type impurity region. ing. The p-type bus bar electrode 805p according to the present embodiment includes not only a portion extending in the X-axis direction but also a portion extending in the Y-axis direction. As a result, the p-type bus bar electrode 805p according to the present embodiment is provided, for example, in an annular shape along the outer edge of the Si substrate 800 (semiconductor substrate).

  According to such a cell 80C, for example, when the p + impurity region 801 is arranged so as to overlap the annular p-type busbar electrode 805p, minority carriers extracted from the p + impurity region 801 can be efficiently collected. That is, in the conventional back electrode type photoelectric conversion element, the minority carriers generated near the outer edge of the semiconductor substrate could not be efficiently collected, whereas in the present embodiment, the minority carriers generated near the outer edge of the Si substrate 800 were generated. Minority carriers can be collected efficiently. In particular, when the area of the Si substrate 800 is small, the proportion of minority carriers generated relatively near the outer edge increases, so that the proportion contributing to the photoelectric conversion efficiency also increases. Therefore, a cell 80C having a particularly high photoelectric conversion efficiency can be obtained.

  In the present embodiment, as shown in FIG. 8, the p-type bus bar electrode 805p has a closed ring shape. For this reason, the current path can be minimized, and the photoelectric conversion loss due to electrical resistance can be minimized. Note that the p-type busbar electrode 805p does not necessarily have to form a closed ring, and may be partially missing.

  On the other hand, the n-type busbar electrode 805n according to the present embodiment extends along the X-axis direction so as to pass through the center of the Si substrate 800 in the Y-axis direction. The n-type bus bar electrode 805n is routed so as to pass through the electrode pad 87 and bypass the electrode pad 86.

  Then, a part of the p-type finger electrode 804p is exposed from the passivation film 807 to form an electrode pad 86. On the other hand, a part of the n-type finger electrode 804n is exposed from the passivation film 807 to form an electrode pad 87.

  FIG. 9 is a partially enlarged view of FIG. Note that FIG. 9 shows a p + impurity region 801 (second conductivity type impurity region) and an n + impurity region 802 (first conductivity type impurity region) in addition to the configuration shown in FIG. In FIG. 9, the same components as those in the above-described first embodiment are denoted by the same reference numerals.

  In the present embodiment, as described above, the p + impurity region 801 of the second conductivity type different from the first conductivity type is arranged so as to overlap the annular p-type busbar electrode 805p. That is, in the cell 80C shown in FIG. 9, the Si substrate 800 (semiconductor substrate) is an n-type (first conductivity type), and the electrode surface 85 of the Si substrate 800 has a p + impurity region 801.

  Then, p + impurity region 801 arranged to overlap with p-type bus bar electrode 805p is provided along the outer edge of Si substrate 800 (semiconductor substrate), as shown in FIG.

  As described above, the p + impurity region 801 provided in this manner enables the minority carriers generated near the outer edge of the Si substrate 800 to be efficiently collected. Therefore, even when the Si substrate 800 having a small area is used, the cell 80C having high photoelectric conversion efficiency can be realized.

  In the present embodiment, as shown in FIG. 8, the p + impurity region 801 has a closed ring shape. Therefore, minority carriers generated near the outer edge of the Si substrate 800 can be collected to the maximum. Note that the p + impurity region 801 does not necessarily have to form a closed ring, and may be partially missing.

  Further, the distance L1 between the outer edge of Si substrate 800 and p + impurity region 801 is not particularly limited, but is preferably 0.01 mm or more and 1.00 mm or less, and is preferably 0.05 mm or more and 0.20 mm or less. More preferred. When the distance L1 is within the above range, the effect of maximally collecting the minority carriers generated in the vicinity of the outer edge can be sufficiently obtained, and at the same time, the manufacturability can be ensured. That is, when the separation distance L1 exceeds the upper limit, minority carriers generated near the outer edge of the Si substrate 800 disappear before moving to the p + impurity region 801 and may not be able to contribute to photoelectric conversion. . On the other hand, when the separation distance L1 is smaller than the lower limit, when cutting out the cell 80A through, for example, a cutting process, it is necessary to particularly increase the accuracy of the cutting process, and the manufacturing difficulty may be increased.

  In the third embodiment as described above, the same effects as in the first embodiment can be obtained. That is, the third embodiment also includes the sub-finger electrode 806. Therefore, the photoelectric conversion efficiency can be increased regardless of the positions of the electrode pads 86 and 87. As a result, for example, the solar cell 80 with high photoelectric conversion efficiency can be realized while the cell 80A is stably fixed by disposing the electrode pads 86 and 87 at the center of the Si substrate 800.

<< 4th Embodiment >>
Next, a cell to which the fourth embodiment of the back electrode type photoelectric conversion element of the present invention is applied will be described in detail.

  FIG. 10 is a plan view showing an electrode surface of a cell to which a fourth embodiment of the back electrode type photoelectric conversion element of the present invention is applied. In FIG. 10, the bus bar electrode 805, the finger electrode 804, and the sub-finger electrode 806 are shown through the passivation film 807 provided on the electrode surface 85.

  Hereinafter, the fourth embodiment will be described. In the following description, differences from the third embodiment will be mainly described, and description of the same items will be omitted. In FIG. 10, the same components as those in the above-described embodiment are denoted by the same reference numerals.

  The fourth embodiment is the same as the third embodiment except that the shape of the sub-finger electrode 806 is different. That is, the cell 80C according to the third embodiment has both the p-type sub-finger electrode 806p and the n-type sub-finger electrode 806n, whereas the cell 80D according to the fourth embodiment has an n-type It has only the sub-finger electrode 806n.

  In addition, the p-type bus bar electrode 805p according to the present embodiment includes, in addition to the ring-shaped portion, a portion connecting this portion to the electrode pad 86.

On the other hand, the n-type bus bar electrode 805n according to the present embodiment is routed so as to pass through the electrode pad 87. Further, the n-type sub-finger electrodes 806n according to the present embodiment are provided on the + Y side and the −Y side of the electrode pad 86, respectively. Then, a part of the p-type bus bar electrode 805p is exposed from the passivation film 807 to form an electrode pad 86. On the other hand, a part of the n-type bus bar electrode 805n is exposed from the passivation film 807 to form an electrode pad 87.
In the above-described fourth embodiment, the same effects as in the third embodiment can be obtained.

<< 5th Embodiment >>
Next, a cell to which the fifth embodiment of the back electrode type photoelectric conversion element of the present invention is applied will be described in detail.

  FIG. 11 is a plan view showing an electrode surface of a cell to which the fifth embodiment of the back electrode type photoelectric conversion element of the present invention is applied. Note that FIG. 11 illustrates the finger electrode 804 and the sub-finger electrode 806 through the passivation film 807 and the bus bar electrode 805 provided on the electrode surface 85. In FIG. 11, only the outline of the bus bar electrode 805 is shown by a dashed line.

  Hereinafter, the fifth embodiment will be described. In the following description, differences from the second embodiment will be mainly described, and description of the same items will be omitted. Note that, in FIG. 11, the same components as those in the above-described embodiment are denoted by the same reference numerals.

  The fifth embodiment is the same as the second embodiment except that the shape of the Si substrate 800 is different. That is, the cell 80E shown in FIG. 11 is obtained by changing two long sides of the cell 80A shown in FIG. 6 into arcs.

  The bus bar electrode 805 provided in the cell 80E is curved along the outer shape of the cell 80E, that is, along an arc.

  Further, the finger electrodes 804 included in the cell 80E extend radially along the radius of the arc.

  The sub-finger electrode 806 included in the cell 80E is branched from the finger electrode 804 and extends along an arc.

  In the fifth embodiment as described above, the same effects as in the second embodiment can be obtained. In addition, the cell 80 </ b> E including a curve in the outer shape contributes to the improvement of design of an electronic device on which the solar cell is mounted.

<Method for manufacturing photoelectric conversion module>
Next, an example of a method for manufacturing the solar cell 80 (photoelectric conversion module) will be described with reference to FIG.

  [1] First, a cell 80A is prepared. The cell 80A is manufactured by, for example, forming an impurity region or the like on a Si wafer, forming an electrode, a contact, an insulating film, and the like, and then dividing the cell. For example, various vapor deposition techniques and a photolithography technique for patterning a film formed thereby are used to form the electrodes, contacts, and insulating films.

  [2] Next, a conductive conductive connection portion 83 is arranged on at least one of the cell 80A and the opening 824. Specifically, the conductive connection part 83 may be arranged on the electrode pad 86 of the cell 80A, or the conductive connection part 83 may be arranged on the opening 824 of the wiring board 82. Note that a metal bump or the like may be formed on the electrode pad 86 or the conductive film 822 in advance.

[3] Next, the cell 80A and the wiring board 82 are overlapped via the conductive connection portion 83. As a result, the conductive connection portion 83 is deformed by receiving a load and spreads in the space inside the opening 824. As a result, the conductive connection portion 83 contacts both the electrode pad 86 of the cell 80A and the conductive film 822 of the wiring board 82, and can electrically and mechanically connect both.
As described above, solar cell 80 is obtained.

<Electronic clock>
Next, an electronic timepiece to which an embodiment of the electronic device of the invention is applied will be described.

  12 and 13 are perspective views each showing an electronic timepiece to which an embodiment of the electronic device of the invention is applied. FIG. 12 is a perspective view showing the appearance of the electronic timepiece when viewed from the front side, and FIG. 13 is a perspective view showing the appearance of the electronic timepiece when viewed from the back side. FIG. 14 is a plan view of the electronic timepiece shown in FIGS. 12 and 13, and FIG. 15 is a longitudinal sectional view of the electronic timepiece shown in FIGS.

  The electronic timepiece 200 includes a case 31, a solar cell 80 (photoelectric conversion module), a device main body 30 including a display unit 50 and an optical sensor unit 40, and two bands 10 attached to the case 31.

  In the present specification, of the electronic timepiece 200 and the solar cell 80, the light source side of light incident on the solar cell 80 is referred to as “front”, and the opposite side is referred to as “back”. A direction axis extending in a direction perpendicular to the light receiving surface 84 of the solar cell 80 is defined as a Z axis. Further, the direction from the back side to the front side of the electronic timepiece 200 is defined as “+ Z direction”, and the opposite direction is defined as “−Z direction”.

  On the other hand, two axes orthogonal to the Z axis are referred to as “X axis” and “Y axis”. Among them, the direction axis connecting the two bands 10 is defined as the Y axis, and the direction axis orthogonal to the Y axis is defined as the X axis. Further, the upward direction of the display unit 50 is defined as “+ Y direction”, and the downward direction is defined as “−Y direction”. Further, the rightward direction in FIG. 14 is defined as “+ X direction”, and the leftward direction is defined as “−X direction”.

Hereinafter, the configuration of the electronic timepiece 200 will be sequentially described.
(Equipment body)
The device main body 30 includes a case 31 opened on the front side and the back side, a windshield 55 provided to cover the opening on the front side, and a bezel 57 provided to cover the surface of the case 31 and the side surface of the windshield 55. And a transparent cover 44 provided so as to close the opening on the back side. Various components described later are housed in the housing.

  Of the housing, the case 31 has an annular shape, and has an opening 35 on the front side in which the windshield plate 55 can be fitted, and an opening (measurement window 45) on the back side in which the transparent cover 44 can be fitted. Have.

  A part of the back side of the case 31 is a convex portion 32 formed so as to protrude. The top of the convex portion 32 is open, and the transparent cover 44 is fitted into the opening, and a part of the transparent cover 44 protrudes from the opening.

  Examples of the constituent material of the case 31 include a metal material such as stainless steel and a titanium alloy, a resin material, a ceramic material, and the like. The case 31 may be an assembly of a plurality of parts, in which case the constituent materials may be different between the parts.

A plurality of operation units 58 (operation buttons) are provided on the outer surface of the case 31.
At the outer edge of the opening 35 provided on the front side of the case 31, a projection 34 projecting in the + Z direction is formed. An annular bezel 57 is provided so as to cover the projection 34.

  Further, a windshield 55 is provided inside the bezel 57. The side surface of the windshield 55 and the bezel 57 are bonded via a bonding member 56 such as packing or an adhesive.

  Examples of a constituent material of the windshield 55 and the transparent cover 44 include a glass material, a ceramic material, and a resin material. In addition, the windshield 55 has translucency, and the display content of the display unit 50 and the light receiving surface 84 of the solar cell 80 can be visually recognized through the windshield 55. Further, the transparent cover 44 also has a light-transmitting property, so that the optical sensor unit 40 can function as a biological information measuring unit.

  Further, the internal space 36 of the housing is a closed space capable of accommodating various components described later.

  The device main body 30 includes the circuit board 20, the azimuth sensor 22 (geomagnetic sensor), the acceleration sensor 23, the GPS antenna 28, the optical sensor unit 40, and the display unit 50 as elements housed in the internal space 36, respectively. It comprises an electro-optical panel 60 and a lighting unit 61, a secondary battery 70, and a solar battery 80. In addition, in addition to these elements, the device main body 30 may include a pressure sensor for calculating altitude, water depth, and the like, a temperature sensor for measuring temperature, various sensors such as an angular velocity sensor, a vibrator, and the like. .

  The circuit board 20 is a board including wiring for electrically connecting the above-described elements. Further, on the circuit board 20, a CPU 21 (Central Processing Unit) including a control circuit, a drive circuit, and the like for controlling operations of the above-described elements, and other circuit elements 24 are mounted.

  In addition, the solar cell 80, the electro-optical panel 60, the circuit board 20, and the optical sensor unit 40 are arranged in this order from the windshield 55 side. As a result, the solar cell 80 is disposed close to the windshield 55, and much external light efficiently enters the solar cell 80. As a result, the photoelectric conversion efficiency of the solar cell 80 can be maximized.

Hereinafter, the elements accommodated in the device main body 30 will be described in more detail.
The circuit board 20 has an end attached to the case 31 via a circuit case 75.

  The connection wiring portion 63 and the connection wiring portion 81 are electrically connected to the circuit board 20. Among them, the circuit board 20 and the electro-optical panel 60 are electrically connected via the connection wiring portion 63. Further, the circuit board 20 and the solar cell 80 are electrically connected via the connection wiring section 81. These connection wiring portions 63 and 81 are formed of, for example, a flexible circuit board, and are efficiently routed through gaps in the internal space 36.

  The direction sensor 22 and the acceleration sensor 23 can detect information related to the movement of the body of the user wearing the electronic timepiece 200. The azimuth sensor 22 and the acceleration sensor 23 output a signal that changes according to the user's body movement and transmit the signal to the CPU 21.

  The CPU 21 controls a GPS receiving unit (not shown) including the GPS antenna 28, a circuit that drives the optical sensor unit 40 to measure a pulse wave or the like of the user, a circuit that drives the display unit 50, Includes circuits for controlling power generation.

  The GPS antenna 28 receives radio waves from a plurality of position information satellites. Further, the device main body 30 includes a signal processing unit (not shown). The signal processing unit performs positioning calculation based on a plurality of positioning signals received by the GPS antenna 28, and acquires time and position information. The signal processing unit transmits these pieces of information to the CPU 21.

  The optical sensor unit 40 is a biological information measuring unit that detects a user's pulse wave and the like. An optical sensor unit 40 illustrated in FIG. 15 includes a light receiving unit 41, a plurality of light emitting units 42 provided outside the light receiving unit 41, and a sensor substrate 43 on which the light receiving unit 41 and the light emitting unit 42 are mounted. It is a sensor. The light receiving unit 41 and the light emitting unit 42 face the measurement window 45 of the case 31 via the transparent cover 44 described above. Further, the circuit board 20 and the optical sensor unit 40 are electrically connected via the connection wiring unit 46 provided in the device main body 30.

  Such an optical sensor unit 40 detects a pulse wave by irradiating the subject (for example, the skin of the user) with light emitted from the light emitting unit 42 and receiving the reflected light with the light receiving unit 41. The optical sensor unit 40 transmits information of the detected pulse wave to the CPU 21.

  Note that, instead of the photoelectric sensor, another sensor such as an electrocardiograph or an ultrasonic sensor may be used.

  The device main body 30 includes a communication unit (not shown). The communication unit transmits various information acquired by the device main body 30 and information stored therein, a calculation result by the CPU 21, and the like to the outside.

  The display unit 50 allows the user to visually recognize the display content of the electro-optical panel 60 via the windshield 55. Thereby, for example, information acquired from the above-described elements can be displayed on the display unit 50 as characters or images, and can be recognized by the user.

  Examples of the electro-optical panel 60 include a liquid crystal display element, an organic EL (Organic Electro Luminescence) display element, an electrophoretic display element, and an LED (Light Emitting Diode) display element.

  FIG. 15 illustrates an example in which the electro-optical panel 60 is a reflective display element (for example, a reflective liquid crystal display element, an electrophoretic display element, or the like). For this reason, the display unit 50 includes an illumination unit 61 provided on a light incident surface of a light guide plate (not shown) included in the electro-optical panel 60. An example of the illumination unit 61 is an LED element. The illumination unit 61 and the light guide plate function as a front light of the reflective display element.

  If the electro-optical panel 60 is a transmissive display device (for example, a transmissive liquid crystal display device), a backlight may be provided instead of the front light.

  When the electro-optical panel 60 is a self-luminous display element (for example, an organic EL display element, an LED display element, or the like) or a non-self-luminous display element using external light, Lights and backlights can be omitted.

  The secondary battery 70 is connected to the circuit board 20 via a wiring (not shown). Thus, the power output from the secondary battery 70 can be used for driving the above-described elements. Further, the secondary battery 70 can be charged by the electric power generated by the solar cell 80.

  The electronic timepiece 200 (electronic device) as described above includes, for example, a solar cell 80 including the above-described cell 80E (backside electrode type photoelectric conversion element). That is, the solar cell 80 includes cells 80a, 80b, 80c, and 80d to which the cell 80E is applied. For this reason, the highly reliable electronic timepiece 200 in which the cells 80a, 80b, 80c, and 80d are stably fixed, and whose photoelectric conversion efficiency is high is obtained.

  Note that any one of the cells 80A, 80B, 80C, and 80D may be provided instead of the cell 80E. Further, instead of the electronic timepiece 200, the solar battery 80 may be mounted on an analog timepiece.

  Although the electronic timepiece 200 has been described above, the embodiment of the electronic device of the invention is not limited to the electronic timepiece, and may be, for example, a mobile phone terminal, a smartphone, a tablet terminal, a wearable terminal, a camera, and the like.

<Modification of electronic timepiece>
Next, a modification of the electronic timepiece to which the embodiment of the electronic apparatus of the invention is applied will be described.

  FIG. 16 is a plan view showing a modification of the electronic timepiece to which the embodiment of the electronic device of the invention is applied. FIG. 17 is a longitudinal sectional view of the electronic timepiece shown in FIG.

  The electronic timepiece 91 includes an outer case 930, a cover glass 933, and a back cover 934, as shown in FIG. 16 or FIG. The outer case 930 is configured by fitting a bezel 932 to a cylindrical case main body 931. A disk-shaped dial 911 is disposed on the inner peripheral side of the bezel 932 via a ring-shaped dial ring 935 as a time display portion.

  On the side surface of the outer case 930, an A button 92 is provided at a position of 2 o'clock from the center of the dial 911, a B button 93 is provided at a position of 4 o'clock, and a crown 94 is provided at a position of 3 o'clock. Have been.

  As shown in FIG. 16 or FIG. 17, the electronic timepiece 91 has a front side opening of two openings of a metal case main body 931 which is closed by a cover glass 933 via a bezel 932, and The opening on the side is closed by a back cover 934.

  Inside the outer case 930, a dial ring 935 attached to the inner periphery of the bezel 932, a light-transmitting dial 911, hands 921 to 924, a calendar wheel 920, each hand 921 to 924, and a calendar And a drive mechanism 9140 for driving the vehicle 920.

  The dial ring 935 includes a flat plate portion parallel to the cover glass 933 and an inclined portion inclined toward the dial 911. A donut-shaped storage space is formed by the flat plate portion and the inclined portion of the dial ring 935 and the inner peripheral surface of the bezel 932, and a ring-shaped antenna 9110 is stored in the storage space.

  The dial 911 is a circular plate for displaying the time inside the outer case 930, and is formed of a light transmissive material such as plastic. In addition, hands 921 to 924 and the like are provided between the dial 911 and the cover glass 933.

  A solar cell 9135 that performs photovoltaic power generation is provided between the dial 911 and the base plate 9125 to which the driving mechanism 9140 is attached. That is, solar cell 9135 is provided on the back side of dial 911. Then, solar cell 9135 receives light transmitted through dial 911 and performs photovoltaic power generation.

  The solar cell 9135 is a circular flat plate in which a plurality of photovoltaic elements for converting light energy into electric energy are connected in series, and is an embodiment of the photoelectric conversion module of the present invention, like the solar cell 80 described above. For this reason, in the solar cell 9135, the cell (the back electrode type photoelectric conversion element) is stably fixed, the photoelectric conversion efficiency is high, and the solar cell 9135 has high reliability.

  The dial 911, the solar cell 9135, and the base plate 9125 are formed with holes through which the pointer shafts 929 of the hands 921 to 923 and the pointer shaft (not shown) of the hands 924 pass. The dial 911 and the solar cell 9135 each have an opening for a small calendar window 919.

  The drive mechanism 9140 is attached to the base plate 9125, and is covered with the circuit board 9120 from the back side. The drive mechanism 9140 has a step motor and a train of gears and the like, and drives the hands 921 to 924 and the calendar wheel 920 by rotating the pointer shaft 929 and the like via the train.

  The circuit board 9120 includes a GPS receiving circuit 945 and a control device 950. Further, the circuit board 9120 and the antenna body 9110 are connected to each other by using an antenna connection pin 9115. On the back cover 934 side of the circuit board 9120 on which the GPS receiving circuit 945 and the control device 950 are provided, a circuit holder 9122 for covering these circuit components is provided. In addition, a secondary battery 9130 such as a lithium ion battery is provided between the main plate 9125 and the back cover 934. Secondary battery 9130 is charged with electric power generated by solar cell 9135.

  The present invention has been described based on the illustrated embodiment, but the present invention is not limited to this.

  For example, the back electrode type photoelectric conversion element, the photoelectric conversion module, and the electronic device of the present invention may be configured such that a part of the elements of the above embodiment is replaced with any element having an equivalent function, , Any element may be added to the above embodiment.

  Further, in the above embodiment, an n-type Si substrate is used, but a p-type Si substrate may be used. That is, in the above-described embodiment, an example is described in which the first conductivity type is n-type and the second conductivity type is p-type. However, the first conductivity type is p-type, and the second conductivity type is n-type. It may be. In the latter case, the relationship between the n-type and p-type in the above embodiment may be interchanged.

10 band, 20 circuit board, 21 CPU, 22 direction sensor, 23 acceleration sensor, 24 circuit element, 28 GPS antenna, 30 device body, 31 case, 32 convex part, 34 Projection part, 35 opening part, 36 internal space, 40 light sensor part, 41 light receiving part, 42 light emitting part, 43 sensor board, 44 transparent cover, 45 measurement window part, 46 connection wiring part Reference numeral 50, display unit, 55, windshield, 56, joining member, 57, bezel, 58, operation unit, 60, electro-optical panel, 61, lighting unit, 63, connection wiring unit, 70, secondary battery, 75 Circuit case, 80 ... solar cell, 80a ... cell, 80b ... cell, 80c ... cell, 80d ... cell, 80A ... cell, 80A '... cell, 80B ... cell, 80C ... cell, 80D ... cell, 80E ... cell, 81 ... Connection wiring 82: wiring board, 83: conductive connection portion, 84: light receiving surface, 85: electrode surface, 86: electrode pad, 87: electrode pad, 91: electronic timepiece, 92: A button, 93: B button, 94: crown, 200: electronic watch, 800: Si substrate, 801: p + impurity region, 802: n + impurity region, 804: finger electrode, 804n: n-type finger electrode, 804p: p-type finger electrode, 805: busbar electrode, 805n: n-type Busbar electrode, 805p ... p-type busbar electrode, 806 ... sub-finger electrode, 806n ... n-type sub-finger electrode, 806p ... p-type sub-finger electrode, 807 ... passivation film, 809n ... electrode unreachable area, 809p ... electrode unreachable area , 811n... N + contact, 811p... P + contact, 814n. 14p: p-type through wiring, 817: passivation film, 821: insulating substrate, 822: conductive film, 823: insulating film, 824: opening, 825: adhesive layer, 911: dial plate, 919: small calendar window, 920 ... Calendar car, 921 pointer, 922 pointer, 923 pointer, 924 pointer, 929 pointer axis, 930 outer case, 931 case body, 932 bezel, 933 cover glass, 934 back cover, 935 Dial ring, 945: GPS receiving circuit, 950: Control device, 9110: Antenna body, 9115: Antenna connection pin, 9120: Circuit board, 9122: Circuit holder, 9125: Ground plate, 9130: Secondary battery, 9135: Solar cell, 9140: drive mechanism, L1: separation distance

Claims (11)

A semiconductor substrate having one surface and the other surface in a front-to-back relationship with the one surface;
A first electrode provided above the one surface of the semiconductor substrate and extending in a first direction;
A second electrode provided above the one surface of the semiconductor substrate, extending in a second direction orthogonal to the first direction, and electrically connected to the first electrode;
A third electrode provided above the one surface of the semiconductor substrate, extending in the first direction, and branching from the second electrode;
A back electrode type photoelectric conversion element comprising:   2. The semiconductor device according to claim 1, further comprising a connection portion provided above the one surface of the semiconductor substrate, arranged inside an outer edge of the semiconductor substrate, and electrically connected to the first electrode. 3. Back-electrode type photoelectric conversion element. The one surface has an impurity region electrically connected to the first electrode,
The back electrode type photoelectric conversion element according to claim 2, wherein the impurity region is arranged at a position shifted from the connection portion in a plan view of the one surface.   The back electrode type photoelectric conversion element according to claim 3, wherein the impurity region surrounds the connection portion. The semiconductor substrate is of a first conductivity type;
The impurity region is of a second conductivity type different from the first conductivity type,
The back electrode type photoelectric conversion element according to claim 3, wherein the impurity region is provided along an outer edge of the semiconductor substrate. The semiconductor substrate is of a first conductivity type;
The impurity region has a first conductivity type impurity region of the first conductivity type and a second conductivity type impurity region of a second conductivity type different from the first conductivity type,
The second conductivity type impurity region is provided along an outer edge of the semiconductor substrate,
The first electrode is a first first electrode electrically connected to the first conductivity type impurity region, and a second first electrode electrically connected to the second conductivity type impurity region. Electrodes,
The back electrode type photoelectric conversion element according to claim 3, wherein the second first electrode is provided along an outer edge of the semiconductor substrate. An insulating layer provided between the first electrode and the second electrode;
A through wiring penetrating the insulating layer and electrically connecting the first electrode and the second electrode;
The back electrode type photoelectric conversion element according to any one of claims 1 to 6, comprising:   The back electrode type photoelectric conversion element according to claim 1, wherein the second electrode is branched from the first electrode.   9. The back electrode type photoelectric conversion element according to claim 1, wherein the semiconductor substrate has a single crystal property. 9. A back electrode type photoelectric conversion element according to any one of claims 1 to 9,
A wiring board provided so as to overlap the back electrode type photoelectric conversion element,
A photoelectric conversion module comprising:   An electronic device comprising the back electrode type photoelectric conversion element according to claim 1.

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