JP7433340B2 - Solar cells, solar devices and solar modules - Google Patents

Description

The present invention relates to a solar cell, a solar cell device including the same, and a solar cell module including the same.

Recently, when modularizing double-sided electrode type solar cells, a method is used that directly electrically and physically connects parts of the solar cells by overlapping them without using conductive connection wires. exists. Such a connection method is called a shingling method, and a plurality of solar cells electrically connected by the shingling method is called a solar cell string (solar cell device) (for example, see Patent Document 1).

In solar cell strings (solar cell devices), more solar cells can be mounted in the limited solar cell mounting area of a solar cell module, increasing the light receiving area for photoelectric conversion and increasing the number of solar cell modules. Output is improved. Furthermore, in the solar cell string (solar cell device), no gaps are created between the solar cells, and the design of the solar cell module is improved.

In order to improve output and design, even when modularizing back-electrode type solar cells, using the shingling method to connect parts of the solar cells by overlapping each other is being considered. (For example, see Patent Document 2).

Japanese Patent Application Publication No. 2017-517145 Special table 2015-534288 publication

When connecting back electrode type solar cells using the shingling method, it is necessary to use a conductive connection line or the like to connect the back electrodes having a step. For example, FIG. 3B of Patent Document 2 discloses a technique for connecting back electrode type solar cells using a connecting wire bent into a substantially U-shape. With this technique, it takes time and effort to connect the solar cell modules due to the work of bending the connection wire into a substantially U-shape and the work of arranging the connection wire between the solar cells.

An object of the present invention is to provide a solar cell, a solar cell device, and a solar cell module that can simplify the connection when parts of the solar cells are overlapped and connected using the shingling method. do.

The solar cell according to the present invention includes a semiconductor substrate, a first conductivity type semiconductor layer and a second conductivity type semiconductor layer stacked on the semiconductor substrate, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. A solar cell comprising a first electrode layer and a second electrode layer corresponding to each other, wherein at least a portion of the first electrode layer is located at one end in the first direction on one main surface of the semiconductor substrate. at least a portion of the second electrode layer is located at the other end in the first direction on the one main surface of the semiconductor substrate, and at the one end of the semiconductor substrate, A notch or an opening is formed, and at least a portion of the first electrode layer and the notch or the opening are arranged on a straight line extending in a second direction intersecting the first direction. has been done.

In the solar cell device according to the present invention, one end in the first direction of one of the adjacent solar cells is the first end of the other solar cell of the adjacent solar cells. A plurality of the above-described solar cells arranged using a shingling method so as to overlap under the other end in the direction, and a wiring member that electrically connects the plurality of solar cells, The wiring member is arranged on a straight line extending in a second direction intersecting the first direction along the one end of the one solar cell, and is arranged along the one end of the one solar cell. The second electrode layer is connected to at least a portion of the first electrode layer, and is connected to the second electrode layer at the other end of the other solar cell through the notch or opening at the one end of the one solar cell. Connected to at least a portion of the electrode layer.

In another solar cell device according to the present invention, one end of one of the adjacent solar cells in the first direction is located at the end of the other solar cell of the adjacent solar cells. The plurality of solar cells described above are arranged using a shingling method so as to overlap under the other end in the first direction, and the adhesive member electrically connects the plurality of solar cells. The adhesive member is made of a paste-like adhesive member, and the second electrode at the other end of the other solar cell is connected to the second electrode at the other end of the other solar cell at the notch or opening at the one end of the one solar cell. It is disposed and connected to at least a portion of the layer, and is raised and connected to at least a portion of the first electrode layer at the one end of the one solar cell.

A solar cell module according to the present invention includes one or more solar cell devices described above.

According to the present invention, when connecting some of the back electrode type solar cells by overlapping each other using the shingling method, this connection can be simplified.

FIG. 1 is a diagram of a solar cell module including a solar cell device according to a first embodiment, viewed from the back side. FIG. 2 is a sectional view taken along line II-II of the solar cell module shown in FIG. 1. FIG. FIG. 2 is a diagram of the solar cell according to the first embodiment seen from the back side. 4 is a sectional view taken along the line IV-IV of the solar cell shown in FIG. 3. FIG. FIG. 5 is a diagram showing an example of a large-sized semiconductor wafer including the solar cells shown in FIGS. 3 and 4. FIG. 2 is a sectional view taken along the line VI-VI of the solar cell device shown in FIG. 1. FIG. FIG. 7 is a cross-sectional view corresponding to line VI-VI of a solar cell device according to a modification. FIG. 7 is a cross-sectional view corresponding to line VI-VI of a solar cell device according to a modification. FIG. 7 is a cross-sectional view corresponding to line VI-VI of a solar cell device according to a modification. FIG. 7 is a cross-sectional view corresponding to line VI-VI of a solar cell device according to a modification. It is a figure which looked at the solar cell module provided with the solar cell device based on the modification of 1st Embodiment from the back surface side. It is a figure which looked at the solar battery cell concerning the modification of a 1st embodiment from the back side. 9 is a diagram showing an example of a large-sized semiconductor wafer including the solar cell shown in FIG. 8. FIG. FIG. 7 is a diagram of a solar cell module including a solar cell device according to a second embodiment, viewed from the back side. 11 is a sectional view taken along the line XI-XI of the solar cell module shown in FIG. 10. FIG. It is a figure which looked at the solar battery cell concerning a 2nd embodiment from the back side. 13 is a diagram showing an example of a large-sized semiconductor wafer including the solar cell shown in FIG. 12. FIG.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the same reference numerals are given to the same or corresponding parts in each drawing. Further, for convenience, hatching, member symbols, etc. may be omitted, but in such cases, other drawings shall be referred to.

[First embodiment]
<Solar cell module>
FIG. 1 is a diagram of a solar cell module including the solar cell device according to the first embodiment, viewed from the back side, and FIG. 2 is a sectional view taken along line II-II of the solar cell module shown in FIG. 1. In FIG. 1, a light-receiving side protection member 3, a backside protection member 4, and a sealing material 5, which will be described later, are omitted, and the wiring member 50 is shown transparently. Further, an XY orthogonal coordinate system is shown in FIGS. 1 and 2 and in the drawings to be described later. The XY plane is a plane along the light receiving surface and the back surface of the solar cell module.

As shown in FIGS. 1 and 2, a solar cell module 100 electrically connects a plurality of back electrode type (also referred to as back bonding type or back contact type) solar cells 2 using a shingling method. A solar cell device (also referred to as a solar cell string) 1 is included.

The solar cell device 1 is sandwiched between a light-receiving side protection member 3 and a back side protection member 4. A liquid or solid sealing material 5 is filled between the light-receiving side protection member 3 and the back side protection member 4, whereby the solar cell device 1 is sealed.

The sealing material 5 seals and protects the solar cell device 1, that is, the solar cell 2, and is used between the light-receiving side surface of the solar cell 2 and the light-receiving side protection member 3, and between the solar cell device 1, that is, the solar cell 2. 2 and the back side protection member 4. The shape of the sealing material 5 is not particularly limited, and examples thereof include a sheet shape. This is because if it is in a sheet shape, it is easy to coat the front and back surfaces of the planar solar cell 2.

The material of the sealing material 5 is not particularly limited, but preferably has a property of transmitting light (translucency). Moreover, it is preferable that the material of the sealing material 5 has an adhesive property that allows the solar cell 2, the light-receiving side protection member 3, and the back side protection member 4 to be bonded together. Examples of such materials include ethylene/vinyl acetate copolymer (EVA), ethylene/α-olefin copolymer, ethylene/vinyl acetate/trialyl isocyanurate (EVAT), polyvinyl butyrate (PVB), and acrylic. Transparent resins such as resins, urethane resins, and silicone resins may be used.

The light-receiving side protection member 3 covers the surface (light-receiving surface) of the solar cell device 1, that is, the solar cell 2, via the sealing material 5, and protects the solar cell 2. Although the shape of the light-receiving side protection member 3 is not particularly limited, a plate-like or sheet-like shape is preferable since it indirectly covers the planar light-receiving surface.

The material for the light-receiving side protection member 3 is not particularly limited, but like the sealing material 5, it is preferably a material that is transparent but resistant to ultraviolet light, such as glass or Examples include transparent resins such as acrylic resins and polycarbonate resins. Further, the surface of the light-receiving side protection member 3 may be processed into an uneven shape, or may be coated with an antireflection coating layer. This is because the light-receiving side protection member 3 makes it difficult to reflect the received light and guides more light to the solar cell device 1.

The backside protection member 4 covers the backside of the solar cell device 1, that is, the solar cell 2, via the sealing material 5 to protect the solar cell 2. The shape of the backside protection member 4 is not particularly limited, but like the light-receiving side protection member 3, a plate-like or sheet-like shape is preferable since it indirectly covers the planar backside.

The material for the backside protection member 4 is not particularly limited, but it is preferably a material that prevents water from entering (has high water impermeability). For example, a resin film such as polyethylene terephthalate (PET), polyethylene (PE), olefin resin, fluorine-containing resin, or silicone-containing resin, or a plate-shaped resin member having translucency such as glass, polycarbonate, or acrylic; Examples include laminates with metal foils such as aluminum foils.

<<Solar cell device>>
In the solar cell device 1, the solar cells 2 are connected in series by partially overlapping the ends of the solar cells 2. Specifically, the light-receiving surface side (for example, the right end side in FIG. 2) of one of the adjacent solar cells 2, 2 in the Y direction (first direction) A part of the other solar cell 2 in the Y direction (the other end side opposite to the above-mentioned one end side, for example, the left end side in FIG. 2) It overlaps with a part of the back surface side (for example, one main surface side).

In this way, the plurality of solar cells 2 are piled up and tilted uniformly in a certain direction, similar to a roof covered with tiles, so the solar cells 2 are electrically connected in this way. This method is called the shingling method. Moreover, a plurality of solar cells 2 connected in a string shape is referred to as a solar cell string (solar cell device). Below, the area where adjacent solar cells 2, 2 overlap will be referred to as an overlapping area Ro.

Adjacent solar cells 2, 2 are bonded together via a wiring member 50 in the overlapping region Ro (details will be described later). As the wiring member 50, a known interconnector such as a tab is used. For example, the wiring member 50 may be a ribbon wire made of a copper core coated with a low melting point metal or solder, a conductive film made of a thermosetting resin film containing low melting point metal particles or metal fine particles, or a plurality of wires. Examples include members formed from knitted fabrics or woven fabrics made of conductive wires (see, for example, JP-A-2016-219799 or JP-A-2014-3161).

The wiring member 50 and the electrode portion of the solar cell 2 are connected via a conductive adhesive member. As the conductive adhesive member, a conductive film formed of a thermosetting resin film containing low melting point metal particles or metal fine particles, a conductive adhesive formed of low melting point metal particles or metal fine particles and a binder, or , solder paste containing solder particles, etc. are used.
The solar cell 2 in the solar cell device 1 will be described below.

<<<Solar cell>>>
FIG. 3 is a diagram of the solar cell 2 in the solar cell device 1 shown in FIGS. 1 and 2, viewed from the back side. The solar cell 2 includes a semiconductor substrate 11 having two main surfaces: one main surface side (for example, a back surface side) and the other main surface side (for example, a light-receiving surface side) opposite thereto. It has a first region 7 and a second region 8. Hereinafter, the main surface of the semiconductor substrate 11 on the side that receives light will be referred to as a light-receiving surface, and the main surface of the semiconductor substrate 11 on the opposite side to the light-receiving surface (one main surface) will be referred to as a back surface.

The first region 7 has a so-called comb-shaped shape and includes a plurality of finger portions 7f corresponding to comb teeth and a bus bar portion 7b corresponding to a support portion of the comb teeth. The bus bar portion 7b extends in the X direction (second direction) along one side of the semiconductor substrate 11, and the finger portion 7f extends from the bus bar portion 7b in the Y direction (first direction) intersecting the X direction. direction).

Similarly, the second region 8 has a so-called comb-like shape and includes a plurality of finger portions 8f corresponding to comb teeth and a bus bar portion 8b corresponding to a support portion of the comb teeth. The bus bar portion 8b extends in the X direction along the side on the other end side opposite to the side on the one end side of the semiconductor substrate 11, and the finger portion 8f extends in the Y direction from the bus bar portion 8b.

The finger portions 7f and 8f have a band shape extending in the Y direction, and are provided alternately in the X direction.
Note that the first region 7 and the second region 8 may be formed in a stripe shape.

FIG. 4 is a sectional view taken along the line IV-IV of the solar cell 2 shown in FIG. As shown in FIG. 4, the solar cell 2 includes an intrinsic semiconductor layer 13 and an antireflection layer 15 that are laminated in this order on the light-receiving surface side of the semiconductor substrate 11. The solar cell 2 also includes an intrinsic semiconductor layer 23, a first conductivity type semiconductor layer 25, and a first electrode layer 27, which are laminated in this order on a part of the back side of the semiconductor substrate 11 (mainly in the first region 7). Be prepared. The solar cell 2 also includes an intrinsic semiconductor layer 33, a second conductivity type semiconductor layer 35, and a second electrode layer, which are laminated in this order on another part of the back side of the semiconductor substrate 11 (mainly the second region 8). Equipped with 37.

Semiconductor substrate 11 is formed of a crystalline silicon material such as single crystal silicon or polycrystalline silicon. The semiconductor substrate 11 is, for example, an n-type semiconductor substrate in which a crystalline silicon material is doped with an n-type dopant. An example of the n-type dopant is phosphorus (P).
The semiconductor substrate 11 functions as a photoelectric conversion substrate that absorbs incident light from the light receiving surface side and generates optical carriers (electrons and holes).

By using crystalline silicon as the material for the semiconductor substrate 11, dark current is relatively small, and even when the intensity of incident light is low, relatively high output (stable output regardless of illumination intensity) can be obtained.

The intrinsic semiconductor layer 13 is formed on the light-receiving surface side of the semiconductor substrate 11. The intrinsic semiconductor layer 23 is formed in the first region 7 on the back side of the semiconductor substrate 11 . The intrinsic semiconductor layer 33 is formed in the second region 8 on the back side of the semiconductor substrate 11 . The intrinsic semiconductor layers 13, 23, and 33 are formed of, for example, an intrinsic (i-type) amorphous silicon material. The intrinsic semiconductor layers 13, 23, and 33 function as passivation layers, suppress recombination of carriers generated in the semiconductor substrate 11, and improve carrier recovery efficiency.

The antireflection layer 15 is formed on the intrinsic semiconductor layer 13 on the light-receiving surface side of the semiconductor substrate 11 . The antireflection layer 15 functions as an antireflection layer that prevents reflection of incident light, and also functions as a protective layer that protects the light-receiving surface side of the semiconductor substrate 11 and the intrinsic semiconductor layer 13 . The antireflection layer 15 is formed of an insulating material, such as silicon oxide (SiO), silicon nitride (SiN), or a composite thereof, such as silicon oxynitride (SiON).

The first conductive type semiconductor layer 25 is formed on the intrinsic semiconductor layer 23, that is, in the first region 7 on the back side of the semiconductor substrate 11. That is, the first conductive type semiconductor layer 25 has a so-called comb-shaped shape, and includes a plurality of finger portions 25f corresponding to comb teeth and a supporting portion of the comb teeth, with one end of the plurality of finger portions 25f connected to each other. and a bus bar portion 25b. The bus bar portion 25b extends in the X direction along one side of the semiconductor substrate 11, and the finger portion 25f extends in the Y direction from the bus bar portion 25b.

The second conductive type semiconductor layer 35 is formed on the intrinsic semiconductor layer 33, that is, in the second region 8 on the back side of the semiconductor substrate 11. That is, the second conductive type semiconductor layer 35 has a so-called comb-shaped shape, and includes a plurality of finger portions 35f corresponding to comb teeth and a supporting portion of the comb teeth, with one end of the plurality of finger portions 35f connected to each other. and a bus bar portion 35b. The bus bar portion 35b extends in the X direction along the other end side of the semiconductor substrate 11, and the finger portion 35f extends in the Y direction from the bus bar portion 35b.

The first conductive type semiconductor layer 25 is made of, for example, an amorphous silicon material. The first conductive type semiconductor layer 25 is, for example, a p-type semiconductor layer in which an amorphous silicon material is doped with a p-type dopant. An example of the p-type dopant is boron (B).

The second conductive type semiconductor layer 35 is made of, for example, an amorphous silicon material. The second conductive type semiconductor layer 35 is, for example, an n-type semiconductor layer in which an amorphous silicon material is doped with an n-type dopant (for example, the above-mentioned phosphorus (P)).

Note that the first conductive type semiconductor layer 25 may be an n-type semiconductor layer, and the second conductive type semiconductor layer 35 may be a p-type semiconductor layer. Further, the semiconductor substrate 11 may be a p-type semiconductor substrate in which a crystalline silicon material is doped with a p-type dopant (for example, the above-mentioned boron (B)).
Further, a portion of the second conductive type semiconductor layer 35 and the intrinsic semiconductor layer 33 may overlap with a portion of the adjacent first conductive type semiconductor layer 25 and the intrinsic semiconductor layer 23 (not shown).

The first electrode layer 27 is formed on the first conductivity type semiconductor layer 25, that is, in the first region 7 on the back side of the semiconductor substrate 11. The second electrode layer 37 is formed on the second conductivity type semiconductor layer 35, that is, in the second region 8 on the back side of the semiconductor substrate 11.

The first electrode layer 27 has a so-called comb-shaped shape, and includes a plurality of first finger electrode parts 27f corresponding to comb teeth, and a supporting part of the comb teeth, with one end of the plurality of first finger electrode parts 27f corresponding to a support part of the comb teeth. It has a connected first bus bar electrode part 27b. The first busbar electrode section 27b corresponds to the busbar section 7b of the first region 7, and extends along the side (one end) of the semiconductor substrate 11 on one end side in the Y direction (first direction). extending in two directions). The first finger electrode portion 27f corresponds to the finger portion 7f of the first region 7 and extends in the Y direction from the first busbar electrode portion 27b. Thereby, at least a portion of the first electrode layer 27 is arranged at one end in the Y direction (first direction) on the back surface of the semiconductor substrate 11.

The second electrode layer 37 has a so-called comb-shaped shape, and includes a plurality of second finger electrode portions 37f corresponding to comb teeth, and a supporting portion of the comb teeth, with one end of the plurality of second finger electrode portions 37f corresponding to a comb tooth support portion. It has a connected second bus bar electrode section 37b. The second busbar electrode portion 37b corresponds to the busbar portion 8b of the second region 8 and extends in the X direction along the side portion (the other end portion) on the other end side of the semiconductor substrate 11 in the Y direction. The second finger electrode portion 37f corresponds to the finger portion 8f of the second region 8, and extends in the Y direction from the second busbar electrode portion 37b. Thereby, at least a portion of the second electrode layer 37 is arranged at the other end in the Y direction (first direction) on the back surface of the semiconductor substrate 11.

The first electrode layer 27 and the second electrode layer 37 may include a transparent electrode layer and a metal electrode layer, or may include only a metal electrode layer. The transparent electrode layer is made of a transparent conductive material. Examples of the transparent conductive material include ITO (Indium Tin Oxide: a composite oxide of indium oxide and tin oxide) and ZnO (Zinc Oxide). The metal electrode layer is formed of a metal material. As the metal material, for example, Cu, Ag, Al, and alloys thereof are used. The metal electrode layer may be formed of a conductive paste material containing metal powder such as silver, for example.

<Details of solar cell>
As shown in FIG. 3, the other end of the solar cell 2, that is, the other end (left end) of the semiconductor substrate 11 has a linear shape along the X direction. At the other end of the solar cell 2 , the second busbar electrode portion 37 b of the second electrode layer 37 is formed in a linear shape along the shape of the other end of the semiconductor substrate 11 .

On the other hand, one end of the solar cell 2, that is, one end (right end) of the semiconductor substrate 11 has a wavy shape (uneven shape) along the straight line L extending in the X direction, and has a wavy shape (uneven shape) along the straight line L extending in the X direction. It has a plurality of convex portions 41 and a plurality of concave portions 42 arranged alternately. The recess 42 forms a notch.

At one end of the solar cell 2, the first busbar electrode portion 27b of the first electrode layer 27 is formed in a wavy shape along the shape of the one end of the semiconductor substrate 11. As a result, at least a portion of the first electrode layer 27 (more specifically, at least a portion of the first busbar electrode portion 27b) is formed in the convex portion 41.

In this way, a notch (recess) 42 is formed at one end of the solar cell 2, that is, one end of the semiconductor substrate 11, and at least a portion of the first electrode layer 27 (more specifically Specifically, at least a portion of the first bus bar electrode portion 27b) and the cutout portion (recessed portion) 42 are arranged on a straight line L extending in the X direction.

Note that the first bus bar electrode section 27b and the second bus bar electrode section 37b may be divided into a plurality of parts as long as they are connected via a wiring member 50, which will be described later.

For example, as shown in FIG. 5, the solar cell 2 is obtained by cutting a large square or semi-square semiconductor wafer. For example, the solar cell 2 is obtained by forming a cutting groove (half-cut) in a large semiconductor wafer using a laser or a dicing saw, and then breaking the wafer along the cutting groove.

The wavy shape at one end of the semiconductor substrate 11 may be a sine wave (or cosine wave) represented by the following equation.
y=αsin(x)

Here, a large-sized semiconductor wafer generally has two cleavage directions 60 that are orthogonal along diagonals due to the crystal structure (crystal orientation) of the semiconductor substrate 11 such as a crystalline silicon layer. Therefore, if the maximum value θ1 of the angle of inclination of the tangent line of the sine wave to the straight line L is close to 45 degrees, that is, if α in the above formula is close to 1, the solar cell 2 will cleave when cutting a large semiconductor wafer. There is a possibility that it will be cut along the direction 60.

In this regard, the maximum value θ1 of the angle of inclination of the tangent of the sine wave to the straight line L may be smaller than 45 degrees, that is, α in the above equation may be smaller than 1. For example, the maximum value θ1 of the angle of inclination of the tangent to the sine wave may be about 30.963 degrees, that is, α may be about 0.6.

In other words, at the point where the slope (absolute value) of the tangent to the sine wave is maximum, the maximum value θ1 (acute angle) of the slope of the tangent to the straight line L is the cleavage direction 60 of the semiconductor substrate 11 with respect to the straight line L. may be smaller than the angle θ2 (acute angle). Thereby, when cutting a large-sized semiconductor wafer, it is possible to reduce the possibility that the solar cell 2 is cut along the cleavage direction 60.

Note that if the maximum value θ1 of the angle of inclination of the tangent line of the sine wave to the straight line L is larger than 45 degrees, that is, if α in the above formula is larger than 1, then the tangent line of the sine wave to the straight line L will be It is expected that there exists x where the angle of inclination is 45 degrees, that is, y=1 in the above formula, and that the film is cleaved along the cleavage direction 60 at that location.

<Details of solar cell device>
As shown in FIGS. 1 and 2, one end (right end) of one of the adjacent solar cells 2, 2 in the Y direction (first direction) is connected to the other solar cell. It overlaps with the other end (left end) of No. 2 in the Y direction. In the overlapping region Ro, at least the second busbar electrode portion 37b of the second electrode layer 37 at the other end of the other solar cell 2 in the notch (recess) 42 at one end of one solar cell 2 Some parts are exposed.

The wiring member 50 is arranged on a straight line L extending in the X direction (second direction) along one end of the wavy shape of one solar cell 2 in the overlapping region Ro. Thereby, the wiring member 50 covers at least a portion of the first electrode layer 27 (more specifically, at least a portion of the first bus bar electrode portion 27b) in the convex portion 41 at one end of one solar cell 2 connected to. In addition, the wiring member 50 connects at least a portion of the second electrode layer 37 ( More specifically, it is connected to at least a portion of the second bus bar electrode section 37b. In this way, a plurality of solar cells are connected in series by the wiring member 50.

FIG. 6A is a sectional view taken along the line VI-VI of the solar cell device 1 shown in FIG. As shown in FIG. 6A, in the convex portion 41 at one end of one of the adjacent solar cells 2, 2, the wiring member 50 is connected to the first electrode layer of one of the solar cells 2. It is connected to the first bus bar electrode section 27b of No. 27 via a conductive adhesive member 52. In the recess (notch) 42 at one end of one solar cell 2, the wiring member 50 connects to the second bus bar electrode portion 37b of the second electrode layer 37 of the other solar cell 2 and the conductive adhesive member 52. connected via.

As explained above, according to the solar cell device 1 and the solar cell module 100 of the first embodiment, one end of one of the adjacent solar cells 2, 2 (for example, FIG. A plurality of solar cells 2 are electrically connected using the shingling method so that the right end (in FIG. 2) overlaps the other end (for example, the left end in FIG. 2) of the other solar cell 2. Ru. As a result, more solar cells 2 can be mounted in the limited solar cell mounting area of the solar cell device 1 and the solar cell module 100, the light receiving area for photoelectric conversion increases, and the solar cell device 1 And the output of the solar cell module 100 is improved. Furthermore, no gaps are created between the solar cells 2, and the design of the solar cell device 1 and the solar cell module 100 is improved.

Moreover, according to the solar cell device 1 and the solar cell module 100 of the first embodiment, since the back electrode type solar cell is used, the electrodes and wiring are not visible, and the design of the solar cell device 1 and the solar cell module 100 is improved. further improves performance.

Further, according to the solar cell 2 of the first embodiment, the notch (recess) 42 is formed at one end of the semiconductor substrate 11 (for example, the right end in FIG. 3), and the first electrode layer 27 (more specifically, at least a portion of the first bus bar electrode portion 27b) and the notch (recess) 42 are arranged on a straight line L extending in the X direction. As a result, a plurality of solar cells 2 and 2 are connected to each other using a shingling method so that one end of one of the adjacent solar cells 2, 2 overlaps with the other end of the other solar cell 2. When arranging solar cells, the convex portion 41 at one end of one solar cell 2 can be easily removed by simply arranging the wiring member 50 on the straight line L in the overlapping region Ro of the adjacent solar cells 2, 2. At least a part of the first electrode layer 27 (more specifically, at least a part of the first bus bar electrode part 27b) and the other end of the other solar cell 2 via the notch (recess) 42 can be electrically connected to at least a portion of the second electrode layer 37 (more specifically, at least a portion of the second busbar electrode portion 37b). Therefore, it is possible to simplify the connection of a solar cell device and a solar cell module in which back electrode type solar cells are electrically connected using a shingling method.

(Modification 1)
In the first embodiment described above, as shown in FIG. 6A, in the recess (notch) 42 at one end of one solar cell 2, the second electrode layer 37 of the other solar cell 2 The wiring member 50 was directly connected to the bus bar electrode portion 37b.

On the other hand, as shown in FIG. 6B, in the recess (notch) 42 at one end of one solar cell 2, the second busbar electrode portion of the second electrode layer 37 of the other solar cell 2 A conductive raising member 53 may be provided on 37b and the wiring member 50 may be connected thereto. According to this, it is possible to further simplify the connection of a solar cell device and a solar cell module in which back electrode type solar cells are electrically connected using a shingling method.

(Modification 2)
Further, as shown in FIG. 6C, an insulating member 54 is provided at the end of one solar cell 2 in a recess (notch) 42 at one end of one solar cell 2. may be arranged between the end surface of one end of one solar cell 2 and the wiring member 50 . Here, the second conductive type semiconductor layer 35 may be disposed at the periphery of the solar cell 2 . According to this, even if the second conductive type semiconductor layer 35 is arranged at the peripheral portion of the solar cell 2, short circuit in one solar cell 2 can be prevented.

(Modification 3)
In addition, as shown in FIG. 6D, the second electrode layer at the other end of the other solar cell 2 can be placed in the recess (notch) 42 at one end of one solar cell 2 without using a wiring member. One solar cell 2 and the other solar cell 2 may be electrically connected using only the conductive adhesive member 55 provided on the second bus bar electrode portion 37b. As the conductive adhesive member 55, a conductive adhesive formed of low-melting metal fine particles or metal fine particles and a binder, a solder paste containing solder particles, or the like is used.

For example, in the recess (notch) 42 at one end of one solar cell 2, at least a portion of the second bus bar electrode portion 37b of the second electrode layer 37 at the other end of the other solar cell 2 is A paste-like conductive adhesive member 55 is applied to. Next, by pressing the other end of the other solar cell 2 and one end of the one solar cell 2, the paste-like conductive adhesive member 55 is applied to the one end of the one solar cell 2. The first electrode layer 27 is raised up to the first bus bar electrode portion 27b.

(Modification 4)
In this case, as shown in FIG. 6E, the first electrode layer 27 is formed on the end surface of one end of one solar cell 2 in the recess (notch) 42 at one end of one solar cell 2. A film may be used.

(Modification 5)
Furthermore, in the embodiment described above, a wavy shape is illustrated as the uneven shape of one end of the solar cell 2, but the uneven shape of the one end of the solar cell 2 is not limited to this. For example, the uneven shape of one end of the solar cell 2 may be rectangular.

FIG. 7 is a diagram of a solar cell module including a solar cell device according to a modification of the first embodiment viewed from the back side, and FIG. 8 is a diagram of a solar cell 2 in the solar cell device 1 shown in FIG. This is a diagram viewed from above. Note that in FIG. 7 as well, like FIG. 1, the light-receiving side protection member 3, back side protection member 4, and sealing material 5 are omitted, and the wiring member 50 is shown transparently.

As shown in FIG. 8, the uneven shape (projections 41 and depressions 42) of one end of the solar cell 2, that is, one end (right end) of the semiconductor substrate 11, may be rectangular. In this case as well, at one end of the solar cell 2, that is, one end of the semiconductor substrate 11, at least a portion of the first busbar electrode portion 27b of the first electrode layer 27 and the notch (recess) 42 are separated. , it is sufficient if they are arranged on the straight line L extending in the X direction.

For example, as shown in FIG. 9, the solar cell 2 is obtained by cutting a large square or semi-square semiconductor wafer.

(Second embodiment)
In the first embodiment described above, the notch portion 42 is provided at one end of the solar cell 2 . In the second embodiment, an opening is provided at one end of the solar cell instead of the notch 42.

FIG. 10 is a diagram of a solar cell module including the solar cell device according to the second embodiment viewed from the back side, and FIG. 11 is a cross-sectional view taken along the line XI-XI of the solar cell module shown in FIG. 10. Similarly to FIG. 1, in FIG. 10, the light-receiving side protection member 3, back side protection member 4, and sealing material 5 are omitted, and the wiring member 50 is shown transparently.

As shown in FIGS. 10 and 11, a solar cell module 100A of the second embodiment differs from the first embodiment in that the solar cell module 100 described above includes a solar cell device 1A instead of the solar cell device 1. . The other configuration of the solar cell module 100A of the second embodiment is the same as that of the solar cell module 100 of the first embodiment.

The solar cell device 1A differs from the first embodiment in that it includes a solar cell 2A instead of the solar cell 2 in the solar cell device 1 described above. The other configuration of the solar cell device 1A of the second embodiment is the same as that of the solar cell device 1 of the first embodiment.

FIG. 12 is a diagram of the solar cell 2A in the solar cell device 1A shown in FIGS. 10 and 11, viewed from the back side. As shown in FIG. 12, a solar cell 2A of the second embodiment is different from the first embodiment in that the solar cell 2 described above has an opening 43 at one end instead of the notch 42. different. The other configuration of the solar cell 2A of the second embodiment is the same as that of the solar cell 2 of the first embodiment.

To explain in detail, one end of the solar cell 2A, that is, one end (right end) of the semiconductor substrate 11, has a linear shape along the X direction, and extends in the X direction along a straight line L extending along the X direction. It has a plurality of openings 43 spaced apart from each other.

At one end of the solar cell 2A, the first busbar electrode portion 27b of the first electrode layer 27 is formed along the shape of the one end of the semiconductor substrate 11 and along the opening 43. As a result, at least a portion of the first electrode layer 27 (more specifically, at least a portion of the first busbar electrode portion 27b) is formed between the openings 43.

In this way, an opening 43 is formed at one end of the solar cell 2A, that is, one end of the semiconductor substrate 11, and at least a portion of the first electrode layer 27 (more specifically, At least a portion of the first busbar electrode portion 27b) and the opening 43 are arranged on a straight line L extending in the X direction.

Note that the first busbar electrode section 27b and the second busbar electrode section 37b may be divided into a plurality of parts as long as they are connected via the wiring member 50.

This solar cell 2A is obtained by cutting a large square or semi-square semiconductor wafer, as shown in FIG. 13, for example.

As shown in FIGS. 10 and 11, one end (right end) of one of the adjacent solar cells 2A, 2A in the Y direction (first direction) is connected to the other solar cell. It overlaps under the other end (left end) of 2A in the Y direction. In the overlapping region Ro, in the opening 43 at one end of one solar cell 2A, at least a portion of the second electrode layer 37 at the other end of the other solar cell 2A (more specifically, the second At least a portion of the busbar electrode portion 37b) is exposed.

The wiring member 50 is arranged on a straight line L extending in the X direction (second direction) along one end of one solar cell 2A in the overlapping region Ro. Thereby, the wiring member 50 connects at least a portion of the first electrode layer 27 (more specifically, at least a portion of the first bus bar electrode portion 27b) between the openings 43 at one end of one solar cell 2A. section). In addition, the wiring member 50 connects at least a portion (more specifically, is connected to at least a portion of the second bus bar electrode section 37b). In this way, a plurality of solar cells are connected in series by the wiring member 50.

In the second embodiment, similarly to FIG. 6A, between the openings 43 at one end of one of the adjacent solar cells 2A, 2A, the wiring member 50 is connected to one solar cell. It may be connected to the first bus bar electrode portion 27b of the first electrode layer 27 of 2A via the conductive adhesive member 52. In the opening 43 at one end of one solar cell 2A, the wiring member 50 is connected to the second bus bar electrode portion 37b of the second electrode layer 37 of the other solar cell 2A via the conductive adhesive member 52. may be done.

Alternatively, similarly to FIG. 6B, a conductive raising member may be placed on the second bus bar electrode portion 37b of the second electrode layer 37 of the other solar cell 2A in the opening 43 at one end of one solar cell 2A. 53 may be provided and the wiring member 50 may be connected thereto.

Alternatively, similarly to FIG. 6C, an insulating member 54 is provided at the end of one solar cell 2A in the opening 43 at one end of one solar cell 2A, and the insulating member 54 is connected to one solar cell 2A. It may be arranged between the end surface of one end of 2A and the wiring member 50.

Alternatively, similarly to FIG. 6D, the second busbar electrode of the second electrode layer 37 at the other end of the other solar cell 2A can be connected to the second bus bar electrode in the opening 43 at one end of one solar cell 2A without using a wiring member. One solar cell 2A and the other solar cell 2A may be electrically connected using only the conductive adhesive member 55 provided on the portion 37b.

In this case, similarly to FIG. 6E, the first electrode layer 27 may be formed on the end surface of one end of one solar cell 2A in the opening 43 at one end of one solar cell 2A.

As explained above, in the solar cell device 1A and the solar cell module 100A of the second embodiment, one end (for example, the right end in FIG. 11) of one of the adjacent solar cells 2A, 2A is The plurality of solar cells 2A are electrically connected using the shingling method so that the end portion) overlaps under the other end portion (for example, the left end portion in FIG. 11) of the other solar cell 2A. As a result, more solar cells 2A can be mounted in the limited solar cell mounting area of the solar cell device 1A and the solar cell module 100A, the light receiving area for photoelectric conversion increases, and the solar cell device 1A And the output of the solar cell module 100A is improved. Further, no gaps are created between the solar cells 2A, and the design of the solar cell device 1A and the solar cell module 100A is improved.

Further, since the solar cell device 1A and the solar cell module 100A of the second embodiment also use back electrode type solar cells, the electrodes and wiring are not visible, and the design of the solar cell device 1A and the solar cell module 100A is improved. Further improvement.

Also, in the solar cell 2A of the second embodiment, an opening 43 is formed at one end of the semiconductor substrate 11 (for example, the right end in FIG. 12), and at least a portion of the first electrode layer 27 (more Specifically, at least a portion of the first busbar electrode portion 27b) and the opening 43 are arranged on a straight line L extending in the X direction. As a result, a plurality of solar cells 2A and 2A are arranged so that one end of one of the adjacent solar cells 2A, 2A overlaps with the other end of the other solar cell 2A. When arranging solar cells, the wiring member 50 is simply placed on the straight line L in the overlapping region Ro of the adjacent solar cells 2A, and the opening 43 at one end of one of the solar cells 2A At least a part of the first electrode layer 27 (more specifically, at least a part of the first busbar electrode part 27b) between the two ends of the other solar cell 2A through the opening 43. At least a portion of the second busbar electrode portion 37b of the two-electrode layer 37 can be electrically connected. Therefore, it is possible to simplify the connection of a solar cell device and a solar cell module in which back electrode type solar cells are electrically connected using a shingling method.

Although the embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and various changes and modifications are possible. For example, in the above-described embodiment, the solar cell 2 includes the comb-shaped first electrode layer 27 and the second electrode layer 37, each having a finger electrode portion and a busbar electrode portion. However, the features of the present invention are not limited thereto, and can also be applied to a solar cell that includes a striped first electrode layer and a second electrode layer that have only finger electrode portions without bus bar electrode portions. In this case, at least a portion of the first electrode layer is disposed on one end in the Y direction (first direction) on the back surface of the semiconductor substrate, and at least a portion of the second electrode layer is disposed on one main surface of the semiconductor substrate. It may be arranged at the other end in the Y direction (first direction).

Moreover, in the embodiment described above, the solar cell 2 of the back electrode type is exemplified. However, the features of the present invention are not limited thereto, and can also be applied to double-sided electrode type solar cells. In this case, at least a portion of the first electrode layer is disposed at one end in the Y direction (first direction) on the back surface of the semiconductor substrate using, for example, a through hole or via, and at least a portion of the second electrode layer is disposed at one end in the Y direction (first direction) on the back surface of the semiconductor substrate. The portion may be disposed at the other end in the Y direction (first direction) on one principal surface of the semiconductor substrate.

Furthermore, in the embodiments described above, the solar cell modules 100, 100A are provided with a single solar cell device 1, 1A. It may also include battery devices 1 and 1A.

Moreover, in the embodiment mentioned above, as shown in FIG. 4, the solar cell devices 1 and 1A including the heterojunction type solar cells 2 and 2A were illustrated. However, the present invention is not limited thereto, and can also be applied to solar cell devices including various solar cells such as homojunction type solar cells.

Further, in the embodiment described above, the solar cells 2 and 2A using crystalline silicon material are illustrated, but the present invention is not limited thereto. For example, various materials such as gallium arsenide (GaAs) may be used as the material for the solar cell.

1.1A solar cell device (solar cell string)
2, 2A Solar cell 3 Light receiving side protection member 4 Back side protection member 5 Sealing material 7 First region 7f, 8f Finger portion 7b, 8b Bus bar portion 8 Second region 11 Semiconductor substrate 11
13, 23, 33 Intrinsic semiconductor layer 15 Antireflection layer 25 First conductivity type semiconductor layer 25f, 35f Finger portion 25b, 35b Busbar portion 27 First electrode layer 27f First finger electrode portion 27b First busbar electrode portion 35 Second conductive layer type semiconductor layer 37 second electrode layer 37f second finger electrode part 37b second busbar electrode part 41 convex part 42 concave part (cutout part)
43 Opening 50 Wiring member 52 Conductive adhesive member 53 Conductive raising member 54 Insulating member 55 Conductive adhesive member (paste)
100,100A solar cell module

Claims (14)

One end of one of the adjacent solar cells in the first direction overlaps with the other end of the other of the adjacent solar cells in the first direction. , multiple solar cells arranged using the shingling method,
a wiring member that electrically connects the plurality of solar cells;
Equipped with
Each of the plurality of solar cells includes a semiconductor substrate, a first conductivity type semiconductor layer and a second conductivity type semiconductor layer stacked on the semiconductor substrate, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. It includes a first electrode layer and a second electrode layer corresponding to each layer,
At least a portion of the first electrode layer is disposed at the one end in the first direction on one main surface of the semiconductor substrate,
At least a portion of the second electrode layer is disposed at the other end in the first direction on the one main surface of the semiconductor substrate,
A notch or an opening is formed in the one end of the semiconductor substrate,
At least a portion of the first electrode layer and the cutout or the opening are arranged on a straight line extending in a second direction intersecting the first direction,
The wiring member is
arranged along the one end of the one solar cell on a straight line extending in the second direction intersecting the first direction,
connected to at least a portion of the first electrode layer at the one end of the one solar cell;
connected to at least a portion of the second electrode layer at the other end of the other solar cell through the notch or opening at the one end of the one solar cell;
solar cell device. The one end portion of the semiconductor substrate has an uneven shape along the straight line,
At least a portion of the first electrode layer is formed in the convex portion,
a recess forming the notch;
The solar cell device according to claim 1. The uneven shape is a sine wave shape,
At a point where the slope of the tangent to the sine wave in the sine wave shape is maximum, the angle of the slope of the tangent to the straight line is smaller than the angle of the cleavage direction of the semiconductor substrate with respect to the straight line.
The solar cell device according to claim 2. The solar cell device according to claim 2 or 3, wherein the one end portion of the semiconductor substrate includes a plurality of the convex portions and a plurality of the concave portions arranged alternately along the straight line. The solar cell device according to claim 1, wherein the one end portion of the semiconductor substrate includes a plurality of the openings along the straight line. A conductive raised portion provided on at least a portion of the second electrode layer at the other end of the other solar cell at the cutout or opening at the one end of the one solar cell. The solar cell device according to any one of claims 1 to 5 , further comprising a member. further comprising an insulating member disposed between the end surface of the one end of the one solar cell and the wiring member in the notch or opening of the one end of the one solar cell; The solar cell device according to any one of claims 1 to 5 . One end of one of the adjacent solar cells in the first direction overlaps with the other end of the other of the adjacent solar cells in the first direction. , multiple solar cells arranged using the shingling method,
an adhesive member that electrically connects the plurality of solar cells;
Equipped with
Each of the plurality of solar cells includes a semiconductor substrate, a first conductivity type semiconductor layer and a second conductivity type semiconductor layer stacked on the semiconductor substrate, and the first conductivity type semiconductor layer and the second conductivity type semiconductor layer. It includes a first electrode layer and a second electrode layer corresponding to each layer,
At least a portion of the first electrode layer is disposed at the one end in the first direction on one main surface of the semiconductor substrate,
At least a portion of the second electrode layer is disposed at the other end in the first direction on the one main surface of the semiconductor substrate,
A notch or an opening is formed in the one end of the semiconductor substrate,
At least a portion of the first electrode layer and the notch or the opening are arranged on a straight line extending in a second direction intersecting the first direction,
The adhesive member is
Consists of paste-like adhesive material,
Disposed and connected to at least a portion of the second electrode layer at the other end of the other solar cell in the notch or opening at the one end of the one solar cell;
raised and connected to at least a portion of the first electrode layer at the one end of the one solar cell;
solar cell device. The one end portion of the semiconductor substrate has an uneven shape along the straight line,
At least a portion of the first electrode layer is formed in the convex portion,
a recess forming the notch;
The solar cell device according to claim 8. The uneven shape is a sine wave shape,
At a point where the slope of the tangent to the sine wave in the sine wave shape is maximum, the angle of the slope of the tangent to the straight line is smaller than the angle of the cleavage direction of the semiconductor substrate with respect to the straight line.
The solar cell device according to claim 9. The solar cell device according to claim 9 or 10, wherein the one end portion of the semiconductor substrate includes a plurality of the convex portions and a plurality of the concave portions arranged alternately along the straight line. The solar cell device according to claim 8, wherein the one end portion of the semiconductor substrate includes a plurality of the openings along the straight line. The first electrode layer is formed on the end surface of the one end of the one solar cell in the notch or opening of the one end of the one solar cell. The solar cell device according to any one of claims 8 to 12 . A solar cell module comprising one or more solar cell devices according to any one of claims 1 to 13 .

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