TW201943095A - Method for manufacturing solar battery cell, method for manufacturing solar battery module, and solar battery module - Google Patents

Abstract

The present invention provides a method for manufacturing a solar battery cell capable of suppressing a decrease in the output of the solar battery cell when the solar battery module using the shingle method is modularized. A method for manufacturing a solar battery cell is used for a solar battery module including at least one solar cell string in which at least two rectangular double-sided electrode-type solar battery cells are electrically connected by a shingle method, and includes a transparent electrode. A layer forming step for forming a transparent electrode layer on two main surfaces of the semiconductor laminate 10, and when forming the transparent electrode layer 20 on one of the two main surfaces, it becomes a solar cell One of the long side regions RL of the long side portion and the short side region RS of the short side portion of the solar cell is provided with a mask, and the direction intersecting the long side region RL is set to the transport direction TD, and the semiconductor is transported on one side The laminated body 10 is formed with a transparent electrode layer 20 by a physical vapor growth method.

Description

Method for manufacturing solar battery cell, method for manufacturing solar battery module, solar battery cell, and solar battery module

The present invention relates to a method for manufacturing a solar battery cell, a method for manufacturing a solar battery module, a solar battery unit, and a solar battery module.

Recently, in the case of modularizing a double-electrode-type solar battery cell, there is a method that directly and electrically and physically overlaps a part of the solar battery cell without using a conductive connecting wire. Sex (for example, Patent Document 1).

This type of connection is called a shingle method. According to this method, it can be considered that more solar battery units can be installed on a limited solar battery unit installation area in the solar battery module, and the light receiving area for photoelectric conversion is increased. Therefore, the output of the solar battery module is improved.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 11-186577

[Problems to be solved by the invention]

In the method for manufacturing a double-sided electrode type solar cell, a semiconductor laminate having a p-type semiconductor layer and an n-type semiconductor layer formed on each of the two main surfaces of a semiconductor substrate is obtained, and A transparent electrode layer and a metal electrode layer are formed on the surface.
Generally, as a method for forming the transparent electrode layer, a physical vapor growth method (PVD method) such as a sputtering method is used. In this case, the patterning using a mask is performed on the film formation of the transparent electrode layers on any of the main surfaces in such a manner that the transparent electrode layers on the two main surfaces of the semiconductor laminate are not short-circuited with each other.

However, the inventors of the present case have found that during patterning using a mask during film formation, the film formation is hindered by the mask, resulting in a film of a transparent electrode layer at the end of a solar cell near the mask. The thickness becomes thinner than the film thickness of the central portion of the solar cell. Accordingly, it is presumed that the resistance of the transparent electrode layer at the end of the solar battery cell increases, and the output of the solar battery cell decreases.

An object of the present invention is to provide a manufacturing method of a solar battery cell, a manufacturing method of a solar battery module, a solar battery unit, and a solar battery module when a solar cell module using a shingle method is modularized.
[Technical means to solve the problem]

The method for manufacturing a solar cell according to the present invention is used for a solar cell module including at least one solar cell string electrically connected to at least two rectangular double-sided electrode-type solar cells using a shingle method, and It includes a step of forming a transparent electrode layer. The step of forming a transparent electrode layer is to form a transparent electrode layer on two main surfaces of a semiconductor laminate. When a transparent electrode layer is formed on one of the two main surfaces, it becomes a solar cell A mask is arranged on the main surface side of the long side region of the long side portion of the cell and the short side region that becomes the short side portion of the solar cell. The semiconductor layer is transported while the direction intersecting the long side region is set as the transport direction. A transparent electrode layer is formed by a physical vapor growth method.

The method for manufacturing a solar cell module of the present invention includes at least one solar cell string electrically connected to at least two rectangular double-sided electrode-type solar cells using a shingle method. The manufacturing method of a battery cell includes a step of forming a transparent electrode layer. The step of forming a transparent electrode layer is formed when a transparent electrode layer is formed on a main surface side of one of two main surfaces of a semiconductor laminate. A mask is disposed on the main surface side of one of the long-side region serving as the long-side portion of the solar battery cell and the short-side region serving as the short-side portion of the solar battery cell. The semiconductor layer is transported while the direction intersecting the long-side region is set as the transport direction The transparent electrode layer is formed on one side by a physical vapor growth method, and the manufacturing method of the solar cell module includes a step of forming a solar cell string. The step of forming the solar cell string is one of adjacent solar cells. One of the long sides on the front side of the conveying direction partially overlaps the other of the adjacent solar cells Yang conveyed under a portion of the cell with a main surface side of the other main surface opposite to the long side of the side portion of the side of the adjacent solar cells are connected to each other after the feeding direction.

The solar battery cell of the present invention is a solar battery module including at least one solar cell string electrically connected to at least two rectangular double-sided electrode-type solar battery cells by a shingle method, and is provided with a semiconductor laminate. And a transparent electrode layer formed on the two main surfaces of the semiconductor multilayer body, and on one of the two main surfaces, the transparent electrode layer in the long side of the other side of the long side of the solar cell The width of the decreasing region at the end is smaller than the width of the decreasing region at the end of the transparent electrode layer in one of the long sides of the solar cell. The so-called decreasing region is the film at the end of the transparent electrode layer. A region where the film thickness of the central portion of the transparent electrode layer decreases.

The solar battery module of the present invention includes at least one solar battery string electrically connected to at least two rectangular double-sided electrode-type solar battery cells by a shingle method. The solar battery unit is the above-mentioned solar battery unit, and The semiconductor laminated body is provided with a transparent electrode layer formed on two principal surfaces of the semiconductor laminated body, and one of the two principal surfaces is transparent on one of the principal surfaces, and the other of the long sides of the long side of the solar cell is transparent. The width of the decreasing region at the end of the electrode layer is smaller than the width of the decreasing region at the end of the transparent electrode layer in the long side of one of the long sides of the solar cell, and one of the adjacent solar cells One of the main surface sides of one of the long side portions of one end side of the solar battery cell is connected to the other side of the other solar battery unit in the adjacent one of the long side portions and is opposite to one of the main surface sides. Under one part of the other main surface side.
[Effect of the invention]

According to the present invention, when the solar cell module using the shingle method is modularized, it is possible to suppress a decrease in the output of the solar cell unit.

One embodiment of the present invention will be described below, but the present invention is not limited to this. Moreover, for convenience, hatching or component symbols may be omitted, but in this case, refer to other drawings. In addition, the dimensions of various components in the drawings are adjusted for the convenience of the observer for convenience.

As described above, in general, a PVD method is used as a method for forming a transparent electrode layer in a solar cell of a double-sided electrode type. In this case, the patterning using a mask is performed on the film formation of the transparent electrode layers on any of the main surfaces in such a manner that the transparent electrode layers on the two main surfaces of the semiconductor laminate are not short-circuited with each other.

However, in a method for manufacturing a solar cell for a shingled solar cell module, as shown in FIG. 1, after a transparent electrode layer 20X is formed on a semiconductor laminate 10X fabricated from a semiconductor substrate, for example, Laser cutting is performed along the cutting line CL on the formation area of the transparent electrode layer 20X to obtain a plurality of rectangular solar cells.
In this case, if laser cutting is performed along the cutting line CL on the formation area of the transparent electrode layer 20X, the transparent electrode layer 20X is attached to the cut surface of the semiconductor laminate 10X, especially the semiconductor substrate (photoelectric conversion substrate). ), The performance of the solar cell is reduced.
In this regard, it is considered that a transparent electrode is not formed near the cutting line CL (for example, refer to FIG. 9 described below). As a method for forming such a transparent electrode layer, patterning using a mask during film formation, or patterning using etching after film formation, etc. are considered. In patterning using etching after film formation, manufacturing time and manufacturing costs increase due to an increase in manufacturing steps and the like.
In this way, from the viewpoint of suppressing the degradation of the performance of the solar cell caused by laser cutting, it is preferable to use a mask patterning when forming a transparent electrode layer on any main surface (for example, refer to the following figure) 8).

However, as described above, the inventors of the present case gained the insight that, in the patterning using a mask during film formation, the film formation is hindered by the mask, resulting in a transparent electrode at the end of the solar cell near the mask The film thickness of the layer becomes thinner than the film thickness of the central portion of the solar cell. Therefore, it is presumed that the resistance of the transparent electrode layer at the end of the solar battery cell increases, and the output of the solar battery cell decreases.

As shown in FIG. 2 and FIG. 3, the inventors of the present case found that the film thickness of the end of the transparent electrode layer 20X near the mask electrode 20X in the transport direction TD of the semiconductor multilayer body 10X in the PVD method is larger than the center of the transparent electrode layer 20X. The relationship between the reduced regions R1 and R2 where the film thickness is reduced (decreased).
As shown in FIG. 2, if the semiconductor laminated body 10X mounted on the tray TRAY and with a mask MASK disposed on one of the main surface sides of the end is transported in the transport direction TD, the semiconductor laminate exposed at the opening of the mask MASK is transported. A transparent electrode layer 20X is formed on the body 10X.
In this case, as shown in FIG. 3, the width W2 of the decreasing region R2 at the end of the transparent electrode layer 20X on the rear side in the transport direction TD is smaller than the decreasing region R1 of the end of the transparent electrode layer 20X on the front side in the transport direction TD. Width W1 (and the width of the decreasing area on the right and left sides of the conveying direction TD: details will be described later). Further, the widths W1 and W2 of the receding region are the lengths of the receding regions in a direction intersecting the end (edge) of the transparent electrode layer 20X and the end (edge) of the semiconductor multilayer body 10X.
In other words, the receding angle θ2 of the receding region R2 of the end portion of the transparent electrode layer 20X on the rear side in the transport direction TD is larger than the receding angle θ1 of the receding region R1 of the end of the transparent electrode layer 20X on the front side in the transport direction TD. The receding angles θ1 and θ2 are the inclination angles of the surface of the receding area of the transparent electrode layer 20X with respect to the main surface of the semiconductor laminate 10X. In other words, the receding angles θ1 and θ2 are the receding angles of the transparent electrode layer 20X with respect to the semiconductor lamination 10X. The inclination angle of a plane parallel to the main surface (a line extending from the surface of a flat portion of the transparent electrode layer 20X).

Therefore, the inventors of the present invention found that in the method for manufacturing a solar battery cell, the width W2 of the reduced region R2 in which the long side portion of the solar battery cell becomes the end of the transparent electrode layer is smaller in the rearward direction of the transport direction TD.
Thereby, the total area of the fading region of the end portion (four sides) of the transparent electrode layer in the solar battery cell is reduced, thereby suppressing the increase in the resistance of the transparent electrode layer at the end portion of the solar battery cell. As a result, a decrease in the output of the solar cell is suppressed.

In addition, the inventors of the present case have found that in the method for manufacturing a solar battery module, when forming a solar battery string that uses a shingle method to electrically connect solar battery cells, one of the adjacent solar battery cells is used in the solar battery string. The width W1 of the decreasing region R1 of the transparent electrode layer is larger, and the end in the front direction of the transport direction TD is smaller than the width W2 of the decreasing region R2 of the transparent electrode layer in the other solar cell. Sub-systems, overlapping adjacent solar cells.
In this way, by arranging the width W1 of the decreasing region R1 of the transparent electrode layer in one solar cell unit to be larger, the end portion on the front side of the transport direction TD is arranged in the width of the decreasing region R2 of the transparent electrode layer in another solar cell unit. W2 has a small light-shielding region at the end portion on the rear side in the transport direction TD, and suppresses a decrease in the output of the solar cell.
Hereinafter, a solar cell module, a solar cell unit, a method of manufacturing a solar cell module, and a method of manufacturing a solar cell unit according to this embodiment will be described in detail.

(Solar battery module)
Fig. 4 is a side view showing a solar cell module according to this embodiment. As shown in FIG. 1, the solar battery module 100 includes at least one solar battery string 2 that is electrically connected to at least two rectangular double-sided electrode-type solar battery cells 1 using a shingle method.

The solar battery cells 1 are connected in series. Specifically, one of the adjacent long side portions of one of the X-direction (+ X-direction) end sides of one of the adjacent solar battery cells 1 and 1 partially overlaps the other one (for example, the light-receiving surface side). The solar cell unit 1 is below a part of the other surface side (for example, the back surface side) of the long side portion of the other end side opposite to the X direction (-X direction). A bus electrode (to be described later) extending in the Y direction is formed on a part of the light receiving surface side of one end side and a part of the back surface side of the other end side of the solar battery cell 1. The bus bar electrode on the light-receiving surface side of one solar battery cell 1 is electrically connected to the bus bar electrode on the back surface side of the other solar battery unit 1 via a conductive adhesive 8 (see FIG. 6 for details).
In this way, if the tiles are laid on the roof, it becomes a stacked structure in which a plurality of solar battery cells 1 are uniformly inclined in a certain direction. Therefore, the method of electrically connecting the solar battery cells 1 in this way is called a shingle. the way. The plurality of solar battery cells 1 connected in a rope shape are referred to as a solar battery string.
Hereinafter, a region where adjacent solar battery cells 1 and 1 overlap is referred to as an overlapping region Ro.

The solar battery cell 1 is sandwiched between the light-receiving-side protective member 3 and the back-side protective member 4. A liquid or solid sealing material 5 is filled between the light-receiving-side protective member 3 and the back-side protective member 4, thereby sealing the solar battery cell 1.

Examples of the conductive adhesive 8 include a conductive adhesive paste. Such a conductive adhesive paste is a paste-like adhesive in which conductive particles are dispersed in a thermosetting adhesive resin material such as an epoxy resin, an acrylic resin, or a polyurethane resin. However, the invention is not limited to this. For example, a conductive adhesive film or an anisotropic conductive film in which conductive particles are dispersed in a thermosetting adhesive resin material and formed into a film shape may be used.

The sealing material 5 seals and protects the solar cell unit 1 and is interposed between the light-receiving-side surface of the solar cell unit 1 and the light-receiving-side protective member 3, and the back surface of the solar cell 1 and the back-side protective member 4. between.
The shape of the sealing material 5 is not particularly limited, and examples thereof include a sheet shape. The reason is that, if it is sheet-like, it is easy to coat the front and back surfaces of the solar cell in a surface shape.
The material of the sealing material 5 is not particularly limited, but it is preferable to have a characteristic (light-transmitting property) for transmitting light. Moreover, it is preferable that the material of the sealing material 5 has adhesiveness to which the solar cell 1, the light receiving side protection member 3, and the back side protection member 4 are adhered.
Examples of such materials include ethylene / vinyl acetate copolymer (EVA), ethylene / α-olefin copolymer, ethylene / vinyl acetate / triallyl isocyanurate (EVAT), and polyvinyl butyraldehyde (PVB ), Acrylic resin, polyurethane resin, or silicone resin.

The light-receiving-side protection member 3 covers the surface (light-receiving surface) of the solar battery cell 1 with a sealing material 5 interposed therebetween, thereby protecting the solar battery cell 1.
The shape of the light-receiving-side protective member 3 is not particularly limited, but it is preferably a plate-like or sheet-like shape in terms of indirectly covering the planar light-receiving surface.
The material of the light-receiving-side protective member 3 is not particularly limited, but it is preferably a material that is light-transmissive and resistant to ultraviolet light, like the sealing material 5, and examples thereof include glass, acrylic resin, or Transparent resin such as polycarbonate resin. In addition, the surface of the light-receiving-side protective member 3 may be processed into a concave-convex shape, or may be covered with an anti-reflection coating. The reason is that if configured in this manner, the light-receiving-side protective member 3 can make it difficult to reflect the received light, and more light can be introduced into the solar battery cell 1.

The back-side protection member 4 covers the back surface of the solar battery cell 1 with a sealing material 5 interposed therebetween to protect the solar battery cell 1.
The shape of the back-side protective member 4 is not particularly limited, but, like the light-receiving-side protective member 3, it is preferably plate-shaped or sheet-shaped in terms of covering the planar back surface indirectly.
The material of the back-side protective member 4 is not particularly limited, but a material (higher water-shielding property) that prevents penetration of water or the like is preferred. For example, a laminate of a resin film such as polyethylene terephthalate (PET), polyethylene (PE), an olefin-based resin, a fluorine-containing resin, or a silicone-containing resin, and a metal foil such as an aluminum foil can be cited.
Hereinafter, the solar battery cell 1 will be described in detail.

(Solar battery unit)
FIG. 5 is a diagram obtained by observing the solar battery cell according to this embodiment from the light receiving surface side, and FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG. 5. The solar battery cell 1 shown in FIGS. 5 and 6 is a rectangular double-sided electrode type solar battery cell. The solar cell 1 includes a semiconductor multilayer body 10 having two main surfaces, a transparent electrode layer 20 formed on a substantially entire surface side (for example, a light-receiving surface side) of the main surfaces of the semiconductor multilayer body 10, and a metal electrode. A layer 21 is formed on the transparent electrode layer 20; a transparent electrode layer 30 is formed on the substantially entire surface of the other surface side (for example, the back surface side) of the main surface of the semiconductor laminate 10; and a metal electrode layer 31 is formed On the transparent electrode layer 30.

FIG. 7 is an enlarged view of a region A of the semiconductor multilayer body 10 shown in FIG. 6. As shown in FIG. 7, the semiconductor multilayer body 10 includes a semiconductor substrate (photoelectric conversion substrate) 110 having two main surfaces, a passivation layer 120 and a first conductive semiconductor layer 121, which are sequentially laminated on the semiconductor substrate 110. One of the main surfaces (for example, the light-receiving surface side); and the passivation layer 130 and the second conductive semiconductor layer 131 are sequentially laminated on the other surface (for example, the back surface) of the main surface of the semiconductor substrate 110.

＜ Semiconductor substrate ＞
As the semiconductor substrate 110, a conductive single crystal silicon substrate such as an n-type single crystal silicon substrate or a p-type single crystal silicon substrate is used. Thereby, a higher photoelectric conversion efficiency is achieved.
The semiconductor substrate 110 is preferably an n-type single crystal silicon substrate. As a result, the carrier life in the crystalline silicon substrate becomes longer. The reason is that in a p-type single crystal silicon substrate, there is a case where a light-induced LID (Light Induced Degradation) which is affected by B (boron) as a p-type dopant is caused by light irradiation. However, in an n-type single crystal silicon substrate, LID is more suppressed.

The semiconductor substrate 110 has a pyramid-shaped fine uneven structure called a texture structure on the back surface side. Thereby, the recovery efficiency of the light which is not absorbed by the semiconductor substrate 110 and passed through is improved.
In addition, the semiconductor substrate 110 may have a fine uneven structure called a pyramid structure called a texture structure on the light receiving surface side. Thereby, the reflection of the incident light on the light receiving surface is reduced, and the light confinement effect in the semiconductor substrate 11 is improved.

The thickness of the semiconductor substrate 110 is preferably 50 μm to 250 μm, more preferably 60 μm to 230 μm, and even more preferably 70 μm to 210 μm. This reduces the material cost.
Moreover, as the semiconductor substrate 110, a conductive polycrystalline silicon substrate, such as an n-type polycrystalline silicon substrate or a p-type polycrystalline silicon substrate, can also be used. In this case, it is more economical to manufacture solar cells.

<First conductivity type semiconductor layer and second conductivity type semiconductor layer>
The first conductive type semiconductor layer 121 is formed on the substantially entire surface of the light receiving surface side of the semiconductor substrate 110, and the second conductive type semiconductor layer 131 is formed on the substantially back surface side of the semiconductor substrate 110. Whole surface.

The first conductive type semiconductor layer 121 is formed of a first conductive type silicon-based layer such as a p-type silicon-based layer. The second conductivity type semiconductor layer 131 is formed of a silicon-based layer of a second conductivity type different from the first conductivity type, such as an n-type silicon-based layer. The first conductive semiconductor layer 121 may be an n-type silicon-based layer, and the second conductive semiconductor layer 131 may be a p-type silicon-based layer.
The p-type silicon-based layer and the n-type silicon-based layer are formed of an amorphous silicon layer or a microcrystalline silicon layer including amorphous silicon and crystalline silicon. As the dopant impurity of the p-type silicon-based layer, B (boron) is preferably used, and as the dopant impurity of the n-type silicon-based layer, P (phosphorus) is preferably used.

＜ Passivation layer ＞
The passivation layers 120 and 130 are formed of an intrinsic silicon-based layer. The passivation layers 120 and 130 function as a passivation layer and suppress re-bonding of carriers.

＜ Transparent electrode layer ＞
The description will be made with reference to FIGS. 5 and 6 again. The transparent electrode layer 20 is formed on the substantially entire surface of the light-receiving surface side of the semiconductor multilayer body 10, and the transparent electrode layer 30 is formed on the substantially entire surface of the rear surface side of the semiconductor multilayer body 10.
The transparent electrode layers 20 and 30 are formed of a transparent conductive material. As the transparent conductive material, transparent conductive metal oxides such as indium oxide, tin oxide, zinc oxide, titanium oxide, and composite oxides thereof are used. Among these, an indium-based composite oxide containing indium oxide as a main component is preferred. From the viewpoint of higher electrical conductivity and transparency, indium oxide is particularly preferred. Furthermore, in order to ensure reliability or higher conductivity, it is preferable to add a dopant to the indium oxide. Examples of the dopant include Sn, W, Zn, Ti, Ce, Zr, Mo, Al, Ga, Ge, As, Si, and S.

The transparent electrode layer 30 is formed using the in-line PVD method without using a mask, and the transparent electrode layer 20 is formed using the in-line PVD method using a mask. The transparent electrode layer 20 is arranged on the light-receiving surface side of the semiconductor multilayer body 10, and a mask is disposed on the long-side region RL that becomes the long-side portion of the solar battery cell 1 and the short-side region RS that becomes the short-side portion of the solar battery cell. The X direction at which the long-side region RL intersects is taken as a conveyance direction, and is formed by a PVD method while conveying the semiconductor multilayer body 10 (described later in detail).
As a result, a reduced region where the film thickness of the end portion (four sides) of the transparent electrode layer 20 near the mask is smaller than the film thickness of the central portion of the transparent electrode layer 20 is formed. The width W2 of the receding region R2 at the end of the transparent electrode layer 20 on the rear side in the X direction (conveying direction) is smaller than the width W1 of the receding region R1 on the end of the transparent electrode layer 20 on the front side in the X direction (conveying direction). The width of the decreasing region of the end of the transparent electrode layer 20 on the right side and the left side (both ends in the crossing direction with respect to the conveying direction) of the direction: details will be described later}. In other words, the width W2 of the fade region R2 of the end portion of the transparent electrode layer 20 in the long side portion of the other end side of the solar cell is smaller than the end portion of the transparent electrode layer 20 in the long side portion of the one end side. The width W1 of the reduced region R1 (and the width of the reduced region of the end of the transparent electrode layer 20 at the short side portion).
In addition, the so-called reduced region refers to a region where the film thickness of the end portion of the transparent electrode layer 20 decreases compared to the film thickness of the central portion of the transparent electrode layer 20, and the width W1, W2 of the so-called reduced region is to the end portion of the transparent electrode layer 20 ( The length of the receding region in the direction in which the edge portion) and the end portion (side portion) of the semiconductor multilayer body 10 intersect.

The receding angle θ2 of the receding region R2 at the end of the transparent electrode layer 20 on the rear side in the X direction (conveying direction) is larger than the receding angle of the receding region R1 on the end of the transparent electrode layer 20 on the front side in the X direction (conveying direction). θ1 {the receding angle of the receding region of the end of the transparent electrode layer 20 on the right and left sides of the X-direction (both ends in the direction of the cross with respect to the conveying direction)}. In other words, the receding angle θ2 of the receding region R2 of the end portion of the transparent electrode layer 20 in the long side portion of the other end side of the solar cell is larger than the end portion of the transparent electrode layer 20 in the long side portion of the one end side of the solar cell The receding angle θ1 of the receding area R1 (and the receding angle of the receding area of the end of the transparent electrode layer 20 in the short side portion).
In addition, the so-called receding angles θ1 and θ2 are the angles of inclination of the surface of the decreasing region of the transparent electrode layer 20 with respect to the main surface of the semiconductor laminate 10, in other words, the decreasing of the transparent electrode layer 20 with respect to the main surface of the semiconductor multilayer 10 Angles of inclination of parallel faces (lines extending from the surface of a flat portion of a transparent electrode).

Furthermore, it is preferable that the long-side region RL of the transparent electrode layer 20 and the decrease regions R1 and R2 of the film thickness of the transparent electrode layer 20 not be formed by the mask are included in the overlapping region Ro.

The metal electrode layer 21 is formed on the transparent electrode layer 20, and the metal electrode layer 31 is formed on the transparent electrode layer 30.
The metal electrode layers 21 and 31 are formed of a metal material. As the metal material, for example, an alloy of Cu, Ag, Al, or the like is used.

The metal electrode layer 21 has a so-called comb shape, and includes a plurality of finger electrode portions 21f corresponding to comb teeth, and a bus bar electrode portion 21b corresponding to a support portion of the comb teeth. The bus bar electrode portion 21b partially overlaps with one of the light receiving surface side (one main surface side) along one end side in the X direction (front side in the conveying direction), particularly the decreasing region R1 of the long side region RL along the front side in the conveying direction. Direction. The finger electrode portion 21f extends from the bus bar electrode portion 21b in the X direction crossing the Y direction.

The metal electrode layer 31 is formed on the back surface side, for example. The metal electrode layer 31 has a comb-like shape similar to the metal electrode layer 21. That is, the metal electrode layer 31 includes a plurality of finger electrode portions 31 f corresponding to comb teeth, and a bus bar electrode portion 31 b corresponding to a support portion of the comb teeth. The bus bar electrode portion 31 b extends along a part of the overlapping area Ro along the rear side (the other main surface side) of the other end side (the rear side in the conveying direction) of the X direction in the Y direction. The finger electrode portion 31f extends from the bus bar electrode portion 31b in the X direction crossing the Y direction. The metal electrode layer 31 is not limited to a comb shape, and may be formed in a rectangular shape over the entire back surface side of the solar battery cell 1, for example.
A conductive adhesive 8 for forming the solar cell string is provided on the overlapping region Ro (for example, the bus electrode portion 31b of the metal electrode layer 31) of the metal electrode layer 31. In addition, the conductive adhesive 8 may be provided on the overlapping area Ro of the metal electrode layer 21 on the light-receiving surface side (for example, the bus electrode portion 21b of the metal electrode layer 21) instead of the overlap of the metal electrode layer 31 provided on the back surface side. Area Ro.

(Manufacturing method of solar cell)
Next, a method for manufacturing a solar cell according to this embodiment will be described with reference to FIGS. 5 to 7 and FIGS. 8 to 11. FIG. 8 is a diagram showing the steps of forming a transparent electrode layer in the method for manufacturing a solar battery cell according to this embodiment, and FIGS. 9 to 11 are diagrams showing the steps of forming a solar cell in the method for manufacturing a solar battery cell according to this embodiment. Illustration.

First, a passivation layer (for example, an intrinsic silicon-based layer) 120 is formed on a substantially entire area of a light receiving surface side of a semiconductor substrate (for example, an n-type single crystal silicon substrate) 110 (see FIG. 7). Further, a passivation layer (for example, an intrinsic silicon-based layer) 130 is formed on the substantially entire area of the back surface side of the semiconductor substrate 110 (see FIG. 7).
Thereafter, a first conductive semiconductor layer (for example, a p-type silicon-based layer) 121 (see FIG. 7) is formed on the passivation layer 120, that is, a substantially entire area of the light receiving surface side of the semiconductor substrate 110. A second conductive type semiconductor layer (for example, an n-type silicon-based layer) 131 is formed on the passivation layer 130, that is, a substantially entire area of the back surface side of the semiconductor substrate 110 (see FIG. 7).

The formation method of the passivation layers 120 and 130, the first conductive type semiconductor layer 121, and the second conductive type semiconductor layer 131 is not particularly limited, but a plasma CVD (chemical vapor deposition) method is preferably used. As the film forming conditions of the plasma CVD method, for example, a substrate temperature of 100 to 300 ° C., a pressure of 20 to 2600 Pa, and a high-frequency power density of 0.004 to 0.8 W / cm ^{2 are} preferably used. As the material gas, for example, a silicon-containing gas such as SiH ₄ or Si ₂ H ₆ or a mixed gas of a silicon-based gas and hydrogen H ₂ is preferably used.
As the dopant additive gas of the first conductive type semiconductor layer 121, for example, B ₂ H ₆ diluted with hydrogen is preferably used. As the dopant addition gas of the second conductive type semiconductor layer 131, for example, PH ₃ diluted with hydrogen is preferably used.
Moreover, in order to improve the light transmittance, for example, impurities such as oxygen and carbon may be added in a small amount. In this case, for example, a gas such as CO ₂ or CH ₄ is introduced during CVD film formation.
According to the film formation using the plasma CVD method, the film quality can be relatively easily controlled according to the film formation conditions, and therefore, the adjustment of the refractive index becomes easy.
The semiconductor laminated body 10 is obtained by the above steps.

Then, as shown in FIG. 8, a transparent electrode layer 20 is formed on the first conductive type semiconductor layer 121, that is, on the light receiving surface side of the semiconductor multilayer body 10, over the entire area.
As a method of forming the transparent electrode layer 20, a physical vapor growth method (PVD) such as a sputtering method is used. At this time, the mask MASK is arranged so as to cover the light-receiving surface side of the predetermined long-side region RL that becomes the long-side portion of the solar battery unit 1 and the predetermined short-side region RS that becomes the short-side portion of the solar battery unit 1, Using the X direction intersecting the long-side region RL as the transport direction TD, the semiconductor laminated body 10 is transported, and the transparent electrode layer 20 is formed on the light receiving surface side of the semiconductor laminated body 10 (transparent electrode layer forming step).

Then, a transparent electrode layer 30 is layered on the second conductive type semiconductor layer 131, that is, the entire entire area of the back surface side of the semiconductor laminate 10.
As a method of forming the transparent electrode layer 30, a physical vapor growth method (PVD) such as a sputtering method is used. At this time, a transparent electrode layer 30 is formed on the rear surface side of the semiconductor multilayer body 10 while the semiconductor multilayer body 10 is conveyed (transparent electrode layer forming step).

The pressure during PVD film formation is preferably 0.3 Pa or more and 0.6 Pa or less. If the pressure is less than 0.3 Pa, the discharge is unstable. If the pressure is greater than 0.6 Pa, the decay region decreases, but the resistance of the transparent electrode layer increases, resulting in a decrease in the rate.
The conveying speed is preferably from 500 mm / minute to 1500 mm / minute. If the conveying speed is greater than 1500 mm / min, the power in the PVD method must be increased in order to obtain the necessary film thickness, but if the power is increased, the performance of the solar cell unit is reduced. If the conveying speed is less than 500 mm / min, the production line must be long-distance in order to obtain the necessary film thickness. However, if the production line is long-distance, the size and cost of the PVD device will be increased.
The width of the conveyance direction TD of the mask arranged in the long-side region RL cut in the following cutting step is preferably 1.0 mm or more and 1.4 mm or less. 1.0 mm is the processing limit. If the width of the mask becomes larger than 1.4 mm, when the solar cell module using the shingle method is modularized, the decrease region does not converge within the overlap region, and the suppression effect of the decrease in the output of the solar cell caused by the decrease region is reduced.

Then, a metal electrode layer 21 is formed on the transparent electrode layer 20, that is, on the light-receiving surface side of the semiconductor multilayer body 10. At this time, a partially overlapping region Ro along one end side in the X direction, in particular, the reduced region R1 along the long side region RL on the front side in the transport direction during film formation of the transparent electrode layer 20 forms a bus bar electrode portion 21b extending in the Y direction. .
A metal electrode layer 31 is formed on the transparent electrode layer 30, that is, on the back surface side of the semiconductor laminate 10. At this time, a bus bar electrode portion 31 b extending in the Y direction is formed in a partially overlapping region Ro on the back surface side (the other main surface side) along the other end side in the X direction (the rear side in the conveying direction).

Thereafter, as shown in FIG. 9 (the metal electrode layer 21 is omitted for convenience), the transparent electrode of the transparent electrode layer 20 is not formed by masking MASK along the cutting line CL in the long-side region RL. The layer 20 is a non-formation region, and the semiconductor multilayer body 10 is cut using a laser. In this way, as shown in FIGS. 10 and 11, the semiconductor multilayer body 10 is subdivided (for convenience, the metal electrode layer 21 is omitted).
Then, through the above steps, the solar cell unit 1 shown in FIG. 5 and FIG. 6 is completed.

(Manufacturing method of solar cell module)
Next, a method for manufacturing a solar cell module according to this embodiment will be described.
First, as shown in FIG. 4, at least two rectangular solar battery cells 1 are electrically connected using a shingle method to obtain a solar battery string 2 (solar battery string forming step). Specifically, one of the light receiving surface sides of the long side portion of the front side of the transport direction TD of one of the adjacent solar cells 1 and 1 overlaps the transport direction TD of the other solar cell 1 Under one part of the back side of the long side portion on the side, adjacent solar battery cells 1 and 1 are connected to each other via a conductive adhesive 8. By making such connection to the required number of solar battery cells 1, a solar battery string 2 including a plurality of solar battery cells 1 is completed.

Then, the back side protection member 4, the sealing material 5, at least one solar cell string 2, the sealing material 5, and the light receiving side protection member 3 are sequentially stacked, and a vacuum bonding machine is used to equalize a specific temperature, Heating and pressing are performed under pressure to seal.
Through the above steps, the solar cell module 100 shown in FIG. 4 is completed.
In addition, the manufacturing method of the solar cell module 100 is not particularly limited.

As described above, according to the method for manufacturing a solar cell according to this embodiment, in the step of forming the transparent electrode layer, when the transparent electrode layer 20 is formed on the light-receiving surface side of the semiconductor multilayer body 10, it becomes the length of the solar cell 1 A mask is arranged on the light-receiving surface side of the long-side region RL of the side portion and the short-side region RS of the short-side portion of the solar cell 1. The X direction intersecting the long-side region RL is set as the transport direction TD, and the semiconductor laminate is transported on one side On the body 10 side, a transparent electrode layer 20 is formed by a PVD method.
According to the solar battery cell 1 obtained by the manufacturing method, the transparent electrode layer 20 is at the light receiving surface side of the semiconductor laminated body 10 and at the end portion of the transparent electrode layer 20 in the long edge portion of the other end side of the long edge portion of the solar cell unit 1. The width W2 of the receding region R2 is smaller than the width W1 of the receding region R1 of the end of the transparent electrode layer 20 in the long side portion of one end side of the long side portion of the solar battery cell 1.
Thereby, the total area of the fading region of the end portion (four sides) of the transparent electrode layer 20 in the solar cell unit 1 is reduced, and the increase in the resistance of the transparent electrode layer 20 at the end portion of the solar cell unit 1 is suppressed. As a result, the decrease in the output of the solar battery cell 1 is suppressed.
Furthermore, according to the method for manufacturing a solar cell according to this embodiment, it is possible to prevent the transparent electrode layer 20 from adhering to the cut surface of the semiconductor multilayer body 10, especially the cut surface of the semiconductor substrate (photoelectric conversion substrate) during laser cutting, so that It is possible to suppress degradation of the performance of the solar battery cell 1.

In addition, according to the manufacturing method of the solar cell module of this embodiment, one of the light receiving surface sides of the long side portion of the front side of the transport direction TD of one of the adjacent solar cells 1 and 1 is overlapped with The adjacent solar cells 1 and 1 are connected to each other under a portion of the rear side of the long side portion on the rear side of the transport direction TD of the other solar cell 1.
According to the solar cell module 100 manufactured by this manufacturing method, a part of the light-receiving surface side of the long side portion of one end side of one of the adjacent solar battery cells 1 and 1 (the transparent electrode layer 20) The width W1 of the reduced region R1 at the end is larger) and is connected to a part of the back side of the long side portion of the other end side of the other solar cell 1 (the width of the reduced region R2 at the end of the transparent electrode layer 20). W2 is smaller).
In this way, by reducing the width W1 of the decreasing region R1 of the transparent electrode layer 20 in one solar battery cell 1 in the transport direction TD, the end portion on the front side of the transparent electrode layer 20 in the other solar battery cell 1 is reduced. The width W2 of the region R2 is small, and the light-shielding region at the end portion on the rear side in the conveying direction TD is suppressed to suppress the decrease in the output of the solar cell 1.

Here, referring to FIGS. 13A to 13E, the relationship between the transport direction TD in the transparent electrode layer forming step and the width W of the recessed region at the end of the transparent electrode layer 20 is verified.
FIG. 13A is an enlarged view of the area B in FIG. 8 when the transport direction TD in the transparent electrode layer formation step is set to the upward direction (+ Y direction), and FIG. 13B is the transport direction TD in the transparent electrode layer formation step. FIG. 13C (equivalent to the above embodiment) is an enlarged view of the area B in FIG. 8 when the right direction (-X direction) is used, and the transport direction TD in the transparent electrode layer forming step is set to the left direction (+ X direction). An enlarged view of a region B in FIG. 8 at this time.
FIG. 13D illustrates a 50% decrease in thickness R1 (50%) of the film thickness at the ends of the transparent electrode layer 20 on the right side of the mask MASK (along the long side region RL that becomes the long side portion on the left side of the solar cell). The width W1 (50%) and the area, the left side of the mask MASK (along the long side area RL that becomes the long side part of the right side of the solar cell), the film thickness at the ends of the transparent electrode layer 20 is 50% of the reduced area R2 (50%) width W2 (50%) and area, the thickness on the upper side of the mask MASK (the short side region RS along the short side portion that becomes the upper side of the solar cell), the film thickness of the end portion of the transparent electrode layer 50 Width W3 (50%) and area of the% decrease region R3 (50%), and the lower side of the mask MASK (the short side region RS along the short side portion that becomes the lower side of the solar cell) transparent electrode layer 20 Table showing the width W4 (50%) and area of the film thickness at the end of the 50% decrease region R4 (50%).
Here, in the above embodiment, the decrease regions R1 and R2 where the film thickness at the end portion of the transparent electrode layer 20 is smaller (decreased) than the film thickness at the center portion of the transparent electrode layer 20 are shown. However, in this verification, As shown in FIG. 13E (cross-sectional view), as the decrease region, the film thickness at the end portion of the transparent electrode layer 20 is reduced (decreased) to a film thickness of 50% or less at the center portion of the transparent electrode layer 20 (100%). 50% decrease area. Accordingly, the width W1 (50%) of the region 50% of the film thickness decrease R1 (50%) and the width W2 (50%) of the region 50% of the film thickness decrease R2 (50%) are the ends of the transparent electrode layer 20. The width in the X direction of a region where the film thickness decreases to 50% or less of the film thickness (100%) of the central portion of the transparent electrode layer 20, and the width W3 (50%) of the so-called film thickness reduction region R3 (50%) and The width W4 (50%) of the film thickness 50% decrease region R4 (50%) is a decrease in the film thickness at the ends of the transparent electrode layer 20 to less than 50% of the film thickness (100%) in the center of the transparent electrode layer 20 The width of the area in the Y direction. In addition, the reduced region and its width are not limited to this. For example, the thickness of the transparent electrode layer 20 may be reduced (decreased) to the thickness of the central portion of the transparent electrode layer 20 (100%). Areas below 100% or below a specified ratio and their widths.
In the table of FIG. 13D, the areas in the 50% film thickness reduction regions R1 (50%), R2 (50%), R3 (50%), and R4 (50%) are shown (in addition, in In the case where the shingle method causes shadow loss, the area is set to "0"). The area loss due to the decrease is a reduction ratio of the area of the transparent electrode layer 20 due to the decrease. The area loss due to the reduction is based on the area ratio of the film thickness 50% of the area of the transparent electrode layer 20 to the areas R1 (50%), R2 (50%), R3 (50%), and R4 (50%). Expression.
Area loss
= Total area of R1 (50%), R2 (50%), R3 (50%), R4 (50%) of 50% decrease in film thickness / area of transparent electrode layer 20 Here, it is transparent to this verification The area of the electrode layer 20 is described. This verification uses a square semiconductor substrate 110 having a length of 156.75 mm on one side, and transparent electrode layers 20, 30, and metal electrodes are formed on the semiconductor laminate 10 in which the semiconductor layers 120, 121, 130, and 131 are formed on the semiconductor substrate 110. After layers 21 and 31, the laser is used to divide in 5 equal parts. In the formation of the transparent electrode layer 20, the long-side region RL that is the long-side portion of the solar cell and corresponds to the long-side region RL that is the end portion of the semiconductor substrate 110, and the short-side region RS that is the short-side portion of the solar cell, and The mask width of the short-side region RS corresponding to the end portion of the semiconductor substrate 110 is set to 1.0 mm. Therefore, the length of the short-side side of the transparent electrode layer 20 in the rectangular solar cell becomes ((156.75-2) / 5) -1.4 = 29.55 (mm) (in addition, 1.4 mm is the mask width), and the area of the transparent electrode layer 20 becomes (156.75-2) × 29.55 = 4752.86 mm ² . The conveying speed is shown in the table of FIG. 13D.

As shown in the tables of FIGS. 13A and 13D, if the transport direction TD in the transparent electrode layer forming step is set to the upward direction (+ Y direction), the left side of the mask (alongside the right side of the solar cell) Long side region RL) Film thickness at the end of transparent electrode layer 20 50% Decreased region R2 (50%) Width W2 (50%), Right side of mask MASK (formed as a solar cell unit The long side area RL on the left side) The film thickness at the ends of the transparent electrode layer 20 is 50%. The width W1 (50%) of the region R1 (50%) is reduced, and the upper side of the mask MASK (belongs to become the sun) The short-side area RS of the short-side portion on the upper side of the battery cell) The film thickness at the end of the transparent electrode layer 20 is 50%. The width W3 (50%) of the reduced area R3 (50%) is larger, which covers the lower side of MASK. (Along the short-side region RS that becomes the short-side portion on the lower side of the solar cell), the width W4 (50%) of the 50% decrease region R4 (50%) of the film thickness of the end portion of the transparent electrode layer 20 is small.
At this time, if the right side of the cutting line CL, that is, the overlapping region Ro of the long side region RL and the decreasing region R1 (50%) of the long side portion that becomes the left side of the solar cell is superimposed on the left side of the cutting line CL, that is, Below the long-side region RL and the decreasing region R2 (50%) of the long-side portion that becomes the right side of the solar cell, along the decreasing region R1 (50) of the long-side region RL that becomes the long-side portion of the left side of the solar cell %) Is covered. On the other hand, the area of the decreasing region R2 (50%) along the long-side region RL that becomes the long-side portion on the right side of the solar cell is larger than 77.4 mm ² . As a result, compared with the total area of the transparent electrode layer 20 in one solar battery cell, the total area of the declining regions R1 (50%), R2 (50%), R3 (50%), and R4 (50%) The area loss is larger at 2.0%.
The reason is that, as shown in FIG. 12B, the solar cell is covered by the overlapping region Ro of the left side (long side) of the width W1 (50%) (area) of the decreasing region R1 (50%) of the solar cell. The width W2 (50%) (area) of the decreasing region R2 (50%) on the right side (long side portion) is also large.

Next, as shown in the tables of FIG. 13B and FIG. 13D, if the transport direction TD in the transparent electrode layer forming step is set to the right direction (-X direction), the left side of MASK is masked (the right side becomes the right side of the solar cell). The long side region RL) The film thickness at the ends of the transparent electrode layer 20 is 50%. The width W2 (50%) of the region R2 (50%) is reduced. The lower side of the mask MASK (formed as a solar cell) Short side region of the short side of the lower side of the unit RS) Film thickness at the end of the transparent electrode layer 20 50% Decreased area R4 (50%) Width W4 (50%), and the upper side of the mask MASK (along The short-side region RS that becomes the short-side portion on the upper side of the solar cell unit) The film thickness at the end of the transparent electrode layer 20 is 50%, and the width W3 (50%) of the reduced region R3 (50%) is larger. The width W1 (50%) of the 50% decrease region R1 (50%) of the film thickness at the end of the transparent electrode layer 20 on the right side (long side region RL along the long side portion that becomes the left side of the solar cell unit) is small.
At this time, if the right side of the cutting line CL, that is, the overlapping region Ro of the long side region RL and the decreasing region R1 (50%) of the long side portion that becomes the left side of the solar cell is superimposed on the left side of the cutting line CL, that is, Below the long-side region RL and the decreasing region R2 (50%) of the long-side portion that becomes the right side of the solar cell, along the decreasing region R1 (50) of the long-side region RL that becomes the long-side portion of the left side of the solar cell %) Is covered. On the other hand, the area of the decreasing region R2 (50%) along the long-side region RL that becomes the long-side portion on the right side of the solar cell is larger than 61.9 mm ² . As a result, compared with the total area of the transparent electrode layer 20 in one solar battery cell, the total area of the declining regions R1 (50%), R2 (50%), R3 (50%), and R4 (50%) The area loss is larger at 2.0%.

13C and 13D, if the transport direction TD in the transparent electrode layer forming step is set to the left direction (+ X direction) (equivalent to the above embodiment), the left side of the mask ( Along the long-side region RL that becomes the long-side portion on the right side of the solar cell), the film thickness at the end of the transparent electrode layer 20 is reduced by 50%, and the width W2 (50%) of the region R2 (50%) is small, which masks MASK. On the right side (long side region RL along the long side portion that becomes the left side of the solar cell), the film thickness at the ends of the transparent electrode layer 20 is 50%, and the width W1 (50%) of the region R1 (50%) is reduced. The thickness of the end of the transparent electrode layer 20 at the lower side of the mask MASK (along the short-side region RS that becomes the short-side portion at the lower side of the solar cell) W4 (50%) width W4 (50%) %), And the width above the mask (the short-side region RS along the short-side portion that becomes the upper side of the solar cell) the thickness of the transparent electrode layer 20 at the end of the 50% decrease region R3 (50%) width W3 (50%) is larger.
At this time, if the right side of the cutting line CL, that is, the overlapping region Ro of the long side region RL and the decreasing region R1 (50%) of the long side portion that becomes the left side of the solar cell is superimposed on the left side of the cutting line CL, that is, Below the long-side region RL and the decreasing region R2 (50%) of the long-side portion that becomes the right side of the solar cell, along the decreasing region R1 (50) of the long-side region RL that becomes the long-side portion of the left side of the solar cell %) Is covered. In addition, the area of the decreasing region R2 (50%) along the long-side region RL that becomes the long-side portion on the right side of the solar cell is relatively small as 15.5 mm ² . As a result, compared with the total area of the transparent electrode layer 20 in one solar battery cell, the total area of the declining regions R1 (50%), R2 (50%), R3 (50%), and R4 (50%) The area loss is small at 1.0%. In this case, it is presumed that the performance of the solar cell unit and the solar cell module is improved by 1.1% compared with the case of FIG. 13A and FIG. 13B.
The reason is that, as shown in FIG. 12A, the solar cell is covered by the overlapping region Ro on the left side (long side) of the width W1 (50%) (area) of the decreasing region R1 (50%) of the solar cell. The width W2 (50%) (area) of the decreasing region R2 (50%) on the right side (long side portion) is small.

Furthermore, in the same conveying direction TD as in FIG. 13C, the conveying speed was set to 600 mm / min, which is 10 times 60 mm / min. As a result, as shown in the table of FIG. 13D, the same result was obtained.
Therefore, in this verification, the conveying speed was set to a low speed of 60 mm / min, but it is estimated that the same tendency was obtained even if the speed was increased.

Then, the size of the mask in the transparent electrode layer forming step is considered.
Considering the contact resistance of the solar battery cells and the area loss due to adhesion and overlap, the width of the overlapping region Ro is preferably set to 1.5 mm. Therefore, as shown in the tables of FIGS. 13C and 13D, in order to fully overlap the decreasing regions R1 having the width W1 = 0.4 mm, the width of the mask on the right side of the cutting line CL is preferably set to 1.1 mm or less.
On the other hand, due to the physical damage of the laser cutting, the passivation film no longer functions within the range of ± 0.15 to 0.3 mm from the cutting line CL, so it is closer to the left than the cutting line CL. The width of the mask is preferably 0.3 mm, for example. The reason is that if the transparent electrode layer is laminated within the above range, the carriers (holes / electrons) moved to the transparent electrode layer by the vicinity of the passivation film that functions and the passivation film that does not function do not move to the metal electrode. Layer to move to a non-functional passivation film, and then bond to the semiconductor substrate 110 again.
After considering the above circumstances, if the width of the mask is set to be less than 1.4 mm, all the decrease regions R1 can be overlapped, and the suppression effect of the decrease in the output of the solar cell caused by the decrease region R1 is large.
Furthermore, the processing limit of the mask is 1.0 mm. Therefore, the width of the mask is preferably 1.0 mm to 1.4 mm.

As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, Various changes and changes are possible. For example, in this embodiment, as shown in FIG. 7, a heterojunction type solar cell and a method for manufacturing the same are illustrated, but the electrode forming method of the feature of the present invention is not limited to a heterojunction type solar cell, and is also applicable to a homogeneous type. Various solar cells such as a junction type solar cell and a method for manufacturing the same.

1‧‧‧ solar cell

2‧‧‧ solar string

3‧‧‧ light-side protection member

4‧‧‧Backside protection member

5‧‧‧sealing material

8‧‧‧ conductive adhesive

10‧‧‧Semiconductor laminate

10X‧‧‧Semiconductor multilayer

20‧‧‧ transparent electrode layer

20X‧‧‧Transparent electrode layer

21‧‧‧metal electrode layer

21b‧‧‧Bus electrode section

21f‧‧‧finger electrode

30‧‧‧ transparent electrode layer

31‧‧‧metal electrode layer

31b‧‧‧Bus electrode section

31f‧‧‧finger electrode

100‧‧‧ solar cell module

110‧‧‧ semiconductor substrate

120‧‧‧ passivation layer

121‧‧‧ the first conductive semiconductor layer

130‧‧‧ passivation layer

131‧‧‧Second conductive semiconductor layer

A‧‧‧ area

B‧‧‧ Area

CL‧‧‧cut line

MASK‧‧‧Mask

R1‧‧‧ Decay area

R2‧‧‧ Decay area

R3‧‧‧ Decay area

R4‧‧‧ Decay area

Ro‧‧‧ overlapping area

RL‧‧‧long side area

RS‧‧‧ Short Side Area

TD‧‧‧ Transport direction

TRAY‧‧‧Tray

W‧‧‧Width

W1‧‧‧Width

W2‧‧‧Width

W3‧‧‧Width

W4‧‧‧Width

X‧‧‧ direction

Y‧‧‧ direction

θ1‧‧‧ receding angle

θ2‧‧‧ receding angle

FIG. 1 is a view showing a transparent electrode layer forming step and a cutting step in a conventional method for manufacturing a solar cell.

FIG. 2 is a view showing a step of forming a transparent electrode layer using a PVD method in a conventional method for manufacturing a solar cell.

FIG. 3 is a view showing a step of forming a transparent electrode layer using a PVD method in a conventional method for manufacturing a solar cell.

Fig. 4 is a side view showing a solar cell module according to this embodiment.

FIG. 5 is a diagram obtained by observing the solar battery cell of this embodiment from the light receiving surface side.

FIG. 6 is a sectional view taken along the line VI-VI shown in FIG. 5.

FIG. 7 is an enlarged view of a region A of the semiconductor multilayer body 10 shown in FIG. 6.

FIG. 8 is a diagram showing the steps of forming a transparent electrode layer in the method for manufacturing a solar battery cell according to this embodiment.

FIG. 9 is a diagram showing a step of forming a solar cell in the method for manufacturing a solar cell according to this embodiment.

FIG. 10 is a diagram showing a step of forming a solar cell in the method for manufacturing a solar cell according to this embodiment.

FIG. 11 is a diagram showing a step of forming a solar cell in the method for manufacturing a solar cell according to this embodiment.

FIG. 12A is a diagram showing an example of overlapping of solar cells.

FIG. 12B is a diagram showing another example of the overlap of solar battery cells.

FIG. 13A is an enlarged view of a region B in FIG. 8 when the transport direction in the transparent electrode layer forming step is set to the upward direction (+ Y direction).

FIG. 13B is an enlarged view of a region B in FIG. 8 when the transport direction in the transparent electrode layer forming step is set to the right direction (-X direction).

FIG. 13C is an enlarged view of a region B in FIG. 8 when the transport direction in the transparent electrode layer forming step is set to the left direction (+ X direction).

FIG. 13D is a table showing the width and area of the area where the film thickness at the ends of the transparent electrode layer in FIG. 13A to FIG. 13B is reduced by 50%.

FIG. 13E is a diagram illustrating a 50% decrease in film thickness.

Claims (11)

A method for manufacturing a solar battery cell, which is used for a solar battery module including at least one solar cell string in which at least two rectangular double-sided electrode-type solar battery cells are electrically connected by a shingle method, The above-mentioned method for manufacturing a solar battery cell includes a step of forming a transparent electrode layer. The step of forming a transparent electrode layer is one in which a transparent electrode layer is formed on two main surfaces of a semiconductor laminate, and a transparent layer is formed on one of the two main surfaces. In the case of the electrode layer, a mask is placed on the main side of the long-side region serving as the long-side portion of the solar battery cell and the short-side region serving as the short-side portion of the solar battery unit, and will intersect the long-side region. The direction was set as a transport direction, and a transparent electrode layer was formed by a physical vapor growth method while the semiconductor laminate was transported. For example, the method for manufacturing a solar cell according to claim 1, further comprising a cutting step of cutting the semiconductor laminate in the long-side region to obtain at least two of the solar cells from the semiconductor laminate. For example, the method for manufacturing a solar battery cell according to claim 1 or 2 further includes a step of forming a bus bar electrode layer. The step of forming the bus bar electrode layer is located on the main surface side of the semiconductor laminate and along the front side of the transport direction. The long side region forms a bus bar electrode, and A bus bar electrode is formed on the other main surface side of the two main surfaces of the semiconductor multilayer body along the long side region on the rear side of the conveying direction. The method for manufacturing a solar battery cell according to any one of claims 1 to 3, wherein the transfer speed in the transparent electrode layer forming step is from 500 mm / minute to 1500 mm / minute. For example, the method for manufacturing a solar battery cell according to claim 2, wherein the width of the transport direction of the mask disposed in the long-side region cut in the cutting step is 1.0 mm or more and 1.4 mm or less. The method for manufacturing a solar battery cell according to any one of claims 1 to 5, wherein the pressure during film formation by the physical vapor growth method in the transparent electrode layer forming step is 0.3 Pa or more and 0.6 Pa or less. A method for manufacturing a solar battery module, which comprises a method for manufacturing a solar battery module including at least one solar cell string electrically connected to at least two rectangular double-sided electrode-type solar battery cells using a shingle method, The above-mentioned solar battery cell is manufactured by a manufacturing method of a solar battery cell. The manufacturing method of the solar battery cell is as described in claim 1, and includes a step of forming a transparent electrode layer. The step of forming the transparent electrode layer is performed on a semiconductor laminate. When a transparent electrode layer is formed on one of the two main surfaces, it is disposed on the one main surface side of the long side region serving as the long side portion of the solar cell and the short side region serving as the short side portion of the solar cell. The mask sets the direction intersecting with the long-side region as a transport direction, while transporting the semiconductor multilayer body, and forming a transparent electrode layer by a physical vapor growth method, The manufacturing method of the solar cell module includes a step of forming a solar cell string, and the step of forming the solar cell string is a step of forming a main surface of a long side portion of the front side of the solar cell in the adjacent transport direction of the solar cell. One of the sides is partially overlapped with a portion of the long side of the rear side of the other solar cell adjacent to the one in which the other side is opposite to the one main surface side, and the adjacent one The solar battery cells are connected to each other. A solar battery unit is used for a solar battery module including at least one solar cell string electrically connected to at least two rectangular double-sided electrode-type solar battery cells by a shingle method, and comprising: Semiconductor laminates; and A transparent electrode layer formed on two main surfaces of the semiconductor laminate; On one of the two main surfaces, the width of the decreasing region of the end of the transparent electrode layer in the long side of the other side of the long side of the solar cell is smaller than the length of the solar cell. The width of the reduced region of the end portion of the transparent electrode layer in the long side portion of one of the side portions, The aforementioned reduced region refers to a region where the film thickness at the end portion of the transparent electrode layer is smaller than the film thickness at the center portion of the transparent electrode layer. If the solar cell of claim 8 has: A bus bar electrode formed on a part of the one main surface side of the one end side of the semiconductor multilayer body, and A bus bar electrode formed on a part of the other main surface side of the other end side of the semiconductor multilayer body. If the solar cell of item 8 or 9, The decreasing angle of the decreasing region of the end of the transparent electrode layer in the long side portion of the other end side of the solar cell is larger than the end of the transparent electrode layer in the long side portion of the one end side of the solar cell. Angle of decrease in the decrease zone, The aforementioned receding angle refers to the angle of the surface of the receding region of the transparent electrode layer with respect to the main surface of the semiconductor laminate. A solar battery module comprising at least one solar battery string electrically connected to at least two rectangular double-sided electrode-type solar battery cells by a shingle method, and The solar battery cell is a solar battery cell according to claim 8, and includes a semiconductor laminate, and a transparent electrode layer formed on both main surfaces of the semiconductor laminate. On one of the two main surfaces, the sun The width of the reduced region of the end portion of the transparent electrode layer in the long side portion of the other end side of the long side portion of the battery cell is smaller than the transparency in the long side portion of one end side of the long side portion of the solar cell. The width of the receding region at the end of the electrode layer, and One of the one major surface sides of the long side portion of the one end side of one of the adjacent solar cells is overlapped and connected to the other end side of the other solar cell in the adjacent solar cells The long side portion is below a part of the other main surface side opposite to the one main surface side.