KR101744535B1

KR101744535B1 - Solar cell and solar cell panel including the same

Info

Publication number: KR101744535B1
Application number: KR1020150103173A
Authority: KR
Inventors: 황성현; 이현호; 오동해; 김진성
Original assignee: 엘지전자 주식회사
Priority date: 2015-07-21
Filing date: 2015-07-21
Publication date: 2017-06-20
Also published as: KR20170011140A

Abstract

A solar cell according to an embodiment of the present invention includes: a semiconductor substrate; A conductive type region located on or above the semiconductor substrate; And an electrode connected to the conductive region and including a plurality of finger lines formed in a first direction and parallel to each other. The plurality of finger lines include a plurality of one-line finger lines having a single-line portion. Wherein the plurality of single finger finger lines includes a first finger line having a first disconnected portion centered at a first position in the first direction and a second finger line having a center at a second position different from the first position in the first direction And a second finger line having a second disconnection portion positioned thereon.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a solar cell,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell and a solar cell panel including the same. More particularly, the present invention relates to a solar cell improved in structure and a solar cell panel including the same.

With the recent depletion of existing energy sources such as oil and coal, interest in alternative energy to replace them is increasing. Among them, solar cells are attracting attention as a next-generation battery that converts solar energy into electric energy.

A plurality of such solar cells are connected in series or in parallel by a ribbon, and are manufactured in the form of a solar cell panel by a packaging process for protecting a plurality of solar cells. Solar panels require long-term reliability because they must be developed for a long time in various environments. At this time, conventionally, a plurality of solar cells are connected by a ribbon.

However, if a solar cell is connected using a ribbon having a large width of about 1.5 mm, since the large width of the ribbon may cause light loss, it is necessary to reduce the number of ribbons disposed in the solar cell. On the other hand, if the number of ribbons is increased in order to reduce the movement distance of the carrier, the resistance is lowered, but the output is greatly lowered in the low intensity light, so that the low radiation characteristic may be degraded.

The present invention provides a solar cell and a solar cell panel including the solar cell, which can improve low emission characteristics with excellent output.

A solar cell panel according to an embodiment of the present invention includes: a plurality of solar cells including first and second solar cells positioned at least adjacent to each other; And a plurality of wiring members connecting the first solar cell and the second solar cell and including rounded portions. Each of the solar cells includes: a semiconductor substrate; A conductive type region located on or above the semiconductor substrate; And an electrode connected to the conductive region and including a plurality of finger lines formed in a first direction and parallel to each other. The plurality of finger lines include a plurality of one-line finger lines having a single-line portion. Wherein the plurality of single finger finger lines includes a first finger line having a first disconnected portion centered at a first position in the first direction and a second finger line having a center at a second position different from the first position in the first direction And a second finger line having a second disconnection portion positioned thereon.

According to this embodiment, it is possible to minimize the shading loss and minimize the moving distance of the carrier while improving the low radiation characteristic, thereby preventing the output of the solar cell panel from being lowered. Therefore, a solar cell or a solar cell panel including the solar cell can have excellent low emission characteristics and high output.

1 is a perspective view illustrating a solar cell panel according to an embodiment of the present invention.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is a partial cross-sectional view illustrating an example of a solar cell included in the solar cell panel of FIG. 1 and a wiring material connected thereto.
4 is a perspective view schematically showing a first solar cell and a second solar cell connected by a wiring material in a plurality of solar cells of the solar cell panel of FIG.
5 is a partial rear plan view showing a solar cell and a wiring material connected thereto corresponding to the portion A in Fig.
6 is a partial rear plan view showing a solar cell and wiring materials connected thereto according to various modified examples of the present invention.
7 is a partial front plan view showing a solar cell and a wiring material connected to the solar cell corresponding to the portion A in Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it is needless to say that the present invention is not limited to these embodiments and can be modified into various forms.

In the drawings, the same reference numerals are used for the same or similar parts throughout the specification. In the drawings, the thickness, the width, and the like are enlarged or reduced in order to make the description more clear, and the thickness, width, etc. of the present invention are not limited to those shown in the drawings.

Wherever certain parts of the specification are referred to as "comprising ", the description does not exclude other parts and may include other parts, unless specifically stated otherwise. Also, when a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it also includes the case where another portion is located in the middle as well as the other portion. When a portion of a layer, film, region, plate, or the like is referred to as being "directly on" another portion, it means that no other portion is located in the middle.

Hereinafter, a solar cell and a solar cell panel according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, the expressions "first "," second ", and the like are used for distinguishing between each other, and the present invention is not limited thereto.

FIG. 1 is a perspective view showing a solar cell panel according to an embodiment of the present invention, and FIG. 2 is a sectional view cut along a line II-II in FIG.

1 and 2, the solar cell panel 100 according to the present embodiment includes a plurality of solar cells 150 and a wiring material 142 for electrically connecting the plurality of solar cells 150. The solar cell panel 100 includes a sealing member 130 that surrounds and seals a plurality of solar cells 150 and a wiring member 142 that connects the solar cells 150 and a front surface 130 that is positioned on the front surface of the solar cell 150 on the sealing member 130. [ A substrate 110 and a rear substrate 120 positioned on the back surface of the solar cell 150 on the sealing member 130. This will be explained in more detail.

First, the solar cell 150 may include a photoelectric conversion unit that converts the solar cell into electric energy, and an electrode that is electrically connected to the photoelectric conversion unit and collects and transfers a current. The plurality of solar cells 150 may be electrically connected in series, parallel, or series-parallel by the wiring member 142. Specifically, the wiring material 142 electrically connects two neighboring solar cells 150 among the plurality of solar cells 150.

The bus ribbons 145 are connected by the wiring members 142 to connect both ends of the wiring material 142 of the solar cell 150 (that is, the solar cell string) forming one row alternately. The bus ribbon 145 may be disposed at an end of the solar cell string and in a direction intersecting the end. These bus ribbons 145 may connect solar cell strings adjacent to each other, or may connect solar cell strings or solar cell strings to a junction box (not shown) that prevents current flow backward. The material, shape, connection structure, etc. of the bus ribbon 145 can be variously modified, and the present invention is not limited thereto.

The sealing material 130 includes a first sealing material 131 located on the front surface of the solar cell 150 connected by the wiring material 142 and a second sealing material 132 located on the rear surface of the solar cell 150 . The first sealing material 131 and the second sealing material 132 prevent moisture and oxygen from entering and chemically bind each element of the solar cell panel 100. The first and second sealing members 131 and 132 may be made of an insulating material having translucency and adhesiveness. For example, an ethylene-vinyl acetate copolymer resin (EVA), a polyvinyl butyral, a silicon resin, an ester-based resin, an olefin-based resin, or the like may be used for the first sealant 131 and the second sealant 132. The rear substrate 120, the second sealing material 132, the solar cell 150, the first sealing material 131 and the front substrate 110 are integrated by a lamination process using the first and second sealing materials 131 and 132, So that the solar cell panel 100 can be constructed.

The front substrate 110 is disposed on the first sealing material 131 to constitute the front surface of the solar cell panel 100 and the rear substrate 120 is disposed on the second sealing material 132 to form the front surface of the solar cell 150. [ Configure the rear. The front substrate 110 and the rear substrate 120 may be formed of an insulating material capable of protecting the solar cell 150 from external shock, moisture, ultraviolet rays, or the like. The front substrate 110 may be made of a light transmissive material through which light can be transmitted, and the rear substrate 120 may be made of a light transmissive material, a non-transmissive material, or a reflective material. For example, the front substrate 110 may be formed of a glass substrate or the like and the rear substrate 120 may have a TPT (Tedlar / PET / Tedlar) type or a base film (e.g., polyethylene terephthalate ) May include a polyvinylidene fluoride (PVDF) resin layer formed on at least one side of the substrate.

However, the present invention is not limited thereto. Accordingly, the first and second sealing materials 131 and 132, the front substrate 110, and the rear substrate 120 may include various materials other than those described above, and may have various shapes. For example, the front substrate 110 or the back substrate 120 may have various shapes (e.g., substrate, film, sheet, etc.) or materials.

3, a solar cell included in a solar cell panel according to an embodiment of the present invention and wiring materials connected thereto will be described in more detail.

3 is a partial cross-sectional view illustrating an example of a solar cell included in the solar cell panel of FIG. 1 and a wiring material connected thereto.

3, a solar cell 150 includes a semiconductor substrate 160, conductive regions 20 and 30 formed on the semiconductor substrate 160 or on the semiconductor substrate 160, And 30, respectively. The conductive regions 20 and 30 may include a first conductive type region 20 having a first conductive type and a second conductive type region 30 having a second conductive type. The electrodes 42 and 44 may include a first electrode 42 connected to the first conductive type region 20 and a second electrode 44 connected to the second conductive type region 30. The first and second passivation films 22 and 32, the antireflection film 24, and the like.

The semiconductor substrate 160 may be composed of a crystalline semiconductor including a single semiconductor material (for example, a Group 4 element). In one example, the semiconductor substrate 160 may be composed of a single crystal or polycrystalline semiconductor (e.g., single crystal or polycrystalline silicon). In particular, the semiconductor substrate 160 may be composed of a single crystal semiconductor (for example, a single crystal semiconductor wafer, more specifically, a single crystal silicon wafer). Then, the solar cell 150 is based on the semiconductor substrate 160 made of a single crystal semiconductor having a high crystallinity and few defects. Accordingly, the solar cell 150 can have excellent electrical characteristics.

The front surface and / or the rear surface of the semiconductor substrate 160 may be textured to have irregularities. The irregularities may be, for example, a pyramid shape having an irregular size, whose outer surface is composed of the (111) surface of the semiconductor substrate 160. If the surface roughness of the front surface of the semiconductor substrate 160 is increased by texturing, the reflectance of light incident through the front surface of the semiconductor substrate 160 may be reduced. Accordingly, the amount of light reaching the pn junction formed by the base region 10 and the first or second conductivity type regions 20 and 30 can be increased, so that the optical loss can be minimized. In this embodiment, the irregularities are formed on the front surface and the rear surface of the semiconductor substrate 160, respectively. However, the present invention is not limited thereto. Therefore, concavities and convexities may be formed on at least one of the front surface and the rear surface of the semiconductor substrate 160, and irregularities may not be formed on the front surface and the rear surface.

In this embodiment, the semiconductor substrate 160 includes a base region 10 having a first or second conductivity type doped with a first or second conductivity type dopant at a low doping concentration. At this time, the base region 10 of the semiconductor substrate 160 may have a lower doping concentration, higher resistance, or lower carrier concentration than one of the first and second conductivity type regions 20 and 30 having the same conductivity type . As an example, the base region 10 may have a second conductivity type in this embodiment.

The semiconductor substrate 160 may include a first conductive type region 20 and a second conductive type region 30. The base region 10 and the conductive regions 20 and 30 constituting the semiconductor substrate 160 in the present embodiment are regions having a crystal structure of the semiconductor substrate 160 and different conductivity types and doping concentrations. For example, in a semiconductor substrate 160, a region including a first conductive dopant and having a first conductivity type is defined as a first conductive type region 20, and a second conductive type dopant is included at a low doping concentration A region having a second conductivity type is defined as a base region 10 and a region having a second conductivity type is doped with a doping concentration higher than that of the base region 10 by a second conductivity type dopant ). &Lt; / RTI >

The first and second conductivity type regions 20 and 30 may be formed as a whole on the front surface and the rear surface of the semiconductor substrate 160. Here, the term " entirely formed " includes not only a complete formation but also a partial formation of an unavoidable region. Thus, the first and second conductivity type regions 20 and 30 can be formed with a sufficient area without additional patterning.

The first conductivity type region 20 may form an emitter region that forms a pn junction with the base region 10. [ The second conductive type region 30 may form a back electric field region forming a back surface field. The rear electric field area serves to prevent carriers from being lost by recombination on the surface of the semiconductor substrate 160 (more precisely, the rear surface of the semiconductor substrate 160).

In this embodiment, the conductive regions 20 and 30 are formed by doping a dopant into the semiconductor substrate 160 to form a doping region constituting a part of the semiconductor substrate 160. However, the present invention is not limited thereto. Therefore, at least one of the first conductive type region 20 and the second conductive type region 30 may be formed of an amorphous, microcrystalline or polycrystalline semiconductor layer or the like, which is formed on the semiconductor substrate 160 as a separate layer. Other variations are possible.

In this embodiment, the first conductivity type region 20 and the second conductivity type region 30 have a homogeneous structure having a uniform doping concentration as a whole. However, the present invention is not limited thereto. Thus, in another embodiment, at least one of the first conductive type region 20 and the second conductive type region 30 may have a selective structure. In the selective structure, it is possible to have a high doping concentration and a low resistance in the portions adjacent to the electrodes 42 and 44 among the conductive type regions 20 and 30, and a low doping concentration and a high resistance in other portions. In yet another embodiment, the second conductivity type region 30 may have a local structure. In the local structure, the second conductivity type region 30 may be locally formed corresponding to the portion where the second electrode 44 is formed.

The first conductivity type dopant included in the first conductivity type region 20 may be an n type or a p type dopant and the second conductivity type dopant included in the base region 10 and the second conductivity type region 30 May be a p-type or n-type dopant. As the p-type dopant, a Group 3 element such as boron (B), aluminum (Al), gallium (Ga) or indium (In) , Bismuth (Bi), and antimony (Sb). The second conductive dopant in the base region 10 and the second conductive dopant in the second conductive type region 30 may be the same material or different materials.

For example, the first conductivity type region 20 may have a p-type, the base region 10 and the second conductivity type region 30 may have an n-type. When the pn junction formed by the first conductivity type region 20 and the base region 10 is irradiated with light, electrons generated by the photoelectric effect move toward the rear surface of the semiconductor substrate 160, And holes are collected toward the front side of the semiconductor substrate 160 and collected by the first electrode 42. Thereby, electric energy is generated. Then, holes having a slower moving speed than electrons may move to the front surface of the semiconductor substrate 160, rather than the rear surface thereof, thereby improving the conversion efficiency. However, the present invention is not limited thereto, and it is also possible that the base region 10 and the second conductivity type region 30 have a p-type and the first conductivity type region 20 has an n-type.

The first and second passivation films 22 and 32 and the anti-reflection film 24 may be formed on the surface of the semiconductor substrate 160. Such an insulating film may be composed of an undoped insulating film which does not contain a dopant separately.

More specifically, a re-passivation film 22 is formed (e.g., contacted) on the front surface of the semiconductor substrate 160, more precisely on the first conductive region 20 formed in the semiconductor substrate 160, An antireflection film 24 may be formed (e.g., in contact) on the first passivation film 22. The second passivation film 32 may be formed on the rear surface of the semiconductor substrate 160 and more precisely on the second conductive type region 30 formed on the semiconductor substrate 160. [

The first passivation film 22 and the antireflection film 24 are substantially formed on the semiconductor substrate 160 except for the portion corresponding to the first electrode 42 (more precisely, the portion where the first opening portion 102 is formed) Can be formed on the entire front surface. Similarly, the second passivation film 32 is formed on the entire rear surface of the semiconductor substrate 160 except the portion corresponding to the second electrode 44 (more precisely, the portion where the second opening 104 is formed) .

The first and second passivation films 22 and 32 are formed in contact with the second conductivity type regions 20 and 30 to immobilize defects existing in the surface or bulk of the conductive type regions 20 and 30. Accordingly, it is possible to increase the open-circuit voltage (Voc) of the solar cell 150 by removing recombination sites of the minority carriers. The antireflection film 24 reduces the reflectance of light incident on the front surface of the semiconductor substrate 160. Accordingly, the amount of light reaching the pn junction formed at the interface between the base region 10 and the first conductive type region 20 can be increased by lowering the reflectance of light incident through the entire surface of the semiconductor substrate 160. Accordingly, the short circuit current Isc of the solar cell 150 can be increased. In this way, the efficiency of the solar cell 150 can be improved by increasing the open-circuit voltage and the short-circuit current of the solar cell 150 by the passivation films 32 and 22 and the anti-reflection film 24.

For example, the passivation films 22 and 32 or the antireflection film 24 may be formed of a material selected from the group consisting of a silicon nitride film, a silicon nitride film containing hydrogen, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, MgF ₂ , ZnS, TiO ₂ and CeO ₂ And may have a multilayer structure in which any one single film or two or more films selected is combined. For example, the first or second passivation film 22, 32 may include a silicon oxide film having a fixed positive charge, a silicon nitride film, or the like when the conductive type regions 20, 30 have an n type, An aluminum oxide film having a fixed negative charge, and the like. In one example, the antireflective film 24 may comprise silicon nitride.

However, the present invention is not limited thereto, and the passivation films 22 and 32 and the anti-reflection film 24 may include various materials. The laminated structure of the insulating film stacked on the front surface and / or the rear surface of the semiconductor substrate 160 can also be variously modified. For example, the insulating film may be stacked in a stacking order different from the stacking order described above. Or the above-described first and second passivation films 22 and 32 and the antireflection film 24, which do not have at least one of the above-described first and second passivation films 22 and 32 and the antireflection film 24, It is also possible to provide another insulating film. Other variations are possible.

The first electrode 42 is electrically connected to the first conductive type via the first opening 102 formed in the insulating film (for example, the first passivation film 22 and the antireflection film 24) And is electrically connected to the region 20. The second electrode 44 is electrically connected to the second conductivity type region 30 through the second opening 104 formed in the insulating film (for example, the second passivation film 32) located on the rear surface of the semiconductor substrate 160 Lt; / RTI > For example, the first electrode 42 may contact the first conductivity type region 20 and the second electrode 44 may contact the second conductivity type region 30.

The first and second electrodes 42 and 44 may be formed of various materials (for example, a metal material) and may have various shapes. The shape of the first and second electrodes 42 and 44 will be described later.

As described above, in this embodiment, the first and second electrodes 42 and 44 of the solar cell 150 have a predetermined pattern, so that the solar cell 150 can receive light from the front and back surfaces of the semiconductor substrate 160 It has a bi-facial structure. Accordingly, the amount of light used in the solar cell 150 can be increased to contribute to the efficiency improvement of the solar cell 150.

However, the present invention is not limited thereto, and it is also possible that the second electrode 44 is formed entirely on the rear side of the semiconductor substrate 160. It is also possible that the first and second conductivity type regions 20 and 30 and the first and second electrodes 42 and 44 are located on one side (for example, the rear side) of the semiconductor substrate 160, It is also possible that at least one of the first and second conductivity type regions 20 and 30 is formed over both sides of the semiconductor substrate 160. That is, the solar cell 150 described above is merely an example, and the present invention is not limited thereto.

The solar cell 150 described above is electrically connected to the neighboring solar cell 150 by the wiring member 142 positioned (for example, in contact with) the first electrode 42 or the second electrode 44, Will be described in more detail with reference to FIG. 4 together with FIGS. 1 to 3. FIG.

4 is a perspective view schematically showing a first solar cell 151 and a second solar cell 152 connected by a wiring material 142 in a plurality of solar cells 150 of the solar cell panel 100 of FIG. to be. In FIG. 4, the first and second solar cells 151 and 152 are schematically shown only on the semiconductor substrate 160 and the electrodes 42 and 44, respectively.

4, two solar cells 150 (for example, the first solar cell 151 and the second solar cell 152) which are adjacent to each other among the plurality of solar cells 150 are connected to the wiring member 142 ). The wiring member 142 is electrically connected to the first electrode 42 positioned on the front surface of the first solar cell 151 and the second solar cell 152 positioned on one side The second electrode 44 located on the rear side of the second electrode 44 is connected. And the other wiring material 1420a is electrically connected to the second electrode 44 located on the rear surface of the first solar cell 151 and the other electrode on the other side of the first solar cell 151 The first electrode 42 is connected. Another wiring material 1420b is disposed between the first electrode 42 located on the front surface of the second solar cell 152 and the rear surface of another solar cell positioned on one side The second electrode 44 is connected to the second electrode 44. Accordingly, the plurality of solar cells 150 can be connected to each other by the wiring materials 142, 1420a, and 1420b. Hereinafter, the description of the wiring material 142 can be applied to all the wiring materials 142, 1420a, and 1420b that connect the two adjacent solar cells 150 to each other.

In this embodiment, the wiring material 142 is formed on the front surface of the first solar cell 151 by the first electrode 42 (more specifically, the bus bar line of the first electrode 42 (reference numeral 42b in Fig. 7, A second portion 162 extending from the first edge 161 to the opposite second edge 162 and a second portion extending from the rear surface of the second solar cell 152 to the second electrode 44 Specifically, it extends from the first edge 161 to the opposite second edge 162 in a state of being connected to the bus bar line (44b in Fig. 6, the same applies hereinafter) of the second electrode 44 And a third portion extending from the front surface of the second edge 162 of the first solar cell 151 to the rear surface of the second solar cell 152 and connecting the first portion and the second portion . As a result, after the wiring member 142 traverses the first solar cell 151 in a partial area of the first solar cell 151, the second solar cell 152 traverses the second solar cell 152 in a partial area of the second solar cell 152 Can be located. As described above, the wiring member 142 has a smaller width than that of the first and second solar cells 151 and 152, and a part (for example, the bus bar electrode 42b) of the first and second solar cells 151 and 152, The first and second solar cells 151 and 152 can be effectively connected even by a small area.

The wiring member 142 may be arranged to extend along the bus bar line 42b while contacting the bus bar line 42b on the bus bar line 42b at the first and second electrodes 42 and 44 have. Thus, the wiring material 142 and the first and second electrodes 42 and 44 are continuously contacted with each other, thereby improving electrical connection characteristics. However, the present invention is not limited thereto. It is also possible that the bus bar lines 42b and 44b are not provided. In this case, the wiring material 142 is provided with a plurality of bus bars 42b and 44b in the direction crossing the finger lines (reference numeral 44a in FIG. 5, May be arranged to contact and connect to the plurality of finger electrodes 42a, 44a across the finger lines 42a, 44a. However, the present invention is not limited thereto.

A plurality of wiring materials 142 may be provided on the basis of one surface of each solar cell 150 to improve the electrical connection characteristics of the neighboring solar cells 150. Particularly, in this embodiment, the wiring material 142 is composed of a wire having a width smaller than that of a ribbon having a relatively wide width (for example, 1 mm to 2 mm) (For example, 2 to 5) of the number of the conventional ribbons 142 are used.

The wiring member 142 includes a core layer 142a made of metal and a solder layer 142b that is thinly coated on the surface of the core layer 142a and includes solder material to enable soldering with the electrodes 42 and 44. [ (142b). For example, the core layer 142a may include Ni, Cu, Ag, Al as a main material (for example, at least 50 wt% or more specifically at least 90 wt%). The solder layer 142b may include a main material such as Pb, Sn, SnIn, SnBi, SnPb, SnPbAg, SnCuAg, or SnCU. However, the present invention is not limited thereto, and the core layer 142a and the solder layer 142b may include various materials.

As described above, when a wire having a width smaller than that of the conventional ribbon is used as the wiring material 142, the material cost can be greatly reduced. Since the width of the wiring member 142 is smaller than that of the ribbons, a sufficient number of the wiring members 142 can be provided to minimize the movement distance of the carriers, thereby improving the output of the solar cell panel 100.

Further, the wire constituting the wiring material 142 according to the present embodiment may include rounded portions. That is, the wire constituting the wiring material 142 may have a round cross section, an elliptic cross section, or a round cross section or a round cross section. Thus, the wiring material 142 can induce reflection or diffuse reflection. The light reflected from the rounded surface of the wire constituting the wiring member 142 is reflected or totally reflected on the front substrate 110 or the rear substrate 120 located on the front or rear surface of the solar cell 150, ). &Lt; / RTI > Thus, the output of the solar cell panel 100 can be effectively improved. However, the present invention is not limited thereto. Therefore, the wire constituting the wiring member 142 may have a polygonal shape such as a quadrangle, or may have various other shapes.

In this embodiment, the width (or diameter) of the wiring material 142 may be 250 to 500 mu. The thickness of the solder layer 142b is very small and may have various thicknesses depending on the position of the wiring material 142. The width of the wiring material 142 may be a width of the core layer 142a, have. Alternatively, the width of the wiring material 142 may be regarded as the width of a portion located on the line portion (reference numerals 421 and 441 in Figs. 5 and 7). The current generated in the solar cell 150 by the wire-shaped wiring material 142 having such a width is efficiently supplied to the external circuit (for example, a bypass diode of a bus ribbon or a junction box) or another solar cell 150 . In this embodiment, the wiring material 142 can be individually positioned and fixed on the electrodes 42 and 44 of the solar cell 150 without being inserted into a separate layer, film, or the like. If the width of the wiring material 142 is less than 250 袖 m, the strength of the wiring material 142 may be insufficient, and the connecting area of the electrodes 42 and 44 may be very small, resulting in poor electrical connection characteristics and low adhesion. If the width of the wiring material 142 exceeds 500 袖 m, the cost of the wiring material 142 increases and the wiring material 142 hinders the incidence of light incident on the front surface of the solar cell 150, thereby increasing the shading loss . The force exerted in the direction in which the wiring member 142 is spaced apart from the electrodes 42 and 44 becomes large so that the adhesion between the wiring member 142 and the electrodes 42 and 44 may be low and the electrodes 42 and 44, It is possible to cause a problem such as cracks in the resin layer 160. In one example, the width of the wiring material 142 may be in the range of 350 to 450um (particularly, 350um to 400um). The output can be improved while increasing the adhesion with the electrodes 42 and 44 in this range.

At this time, the number of the wiring materials 142 may be 6 to 33 based on one surface of the solar cell 150. More specifically, when the width of the wiring material 142 is 250um or more and less than 300um, the number of the wiring materials 142 may be 15 to 33. [ When the width of the wiring material 142 is 300 袖 m or more and less than 350 袖 m, the number of the wiring materials 142 may be 10 to 33. When the width of the wiring material 142 is 350um or more and less than 400um, the number of the wiring materials 142 may be 8 to 33. [ When the width of the wiring material 142 is 400 탆 to 500 탆, the number of the wiring materials 142 may be 6 to 33. When the width of the wiring member 142 is 350 m or more, the output of the solar cell panel 100 is hardly increased even if the number of the wiring members 142 exceeds 15. If the number of the wiring materials 142 increases, the solar cell 150 may be burdened. In consideration of this, when the width of the wiring material 142 is 350um or more and less than 400um, the number of the wiring materials 142 may be 8 to 15. When the width of the wiring material 142 is 400 탆 to 500 탆, the number of the wiring materials 142 may be 6 to 15. At this time, in order to further improve the output of the solar cell panel 100, the number of the wiring materials 142 may be 10 or more (for example, 12 to 13). However, the present invention is not limited thereto, and the number of the wiring materials 142 and the number of the bus bar lines 42b and 44b may have different values.

At this time, the pitch of the wiring material 142 (or the pitch of the bus bar lines 42b and 44b) may be 4.75 mm to 26.13 mm. This takes into consideration the width and the number of the wiring materials 142. [ For example, when the width of the wiring material 142 is 250um or more and less than 300um, the pitch of the wiring material 142 may be 4.75mm to 10.45mm. When the width of the wiring material 142 is 300um or more and less than 350um, the pitch of the wiring material 142 may be 4.75mm to 15.68mm. When the width of the wiring material 142 is 350um or more and less than 400um, the pitch of the wiring material 142 may be 4.75mm to 19.59mm. When the width of the wiring material 142 is 400um to 500um, the pitch of the wiring material 142 may be 4.75mm to 26.13mm. More specifically, when the width of the wiring material 142 is 350um or more and less than 400um, the pitch of the wiring material 142 may be 10.45mm to 19.59mm. When the width of the wiring material 142 is 400 to 500 mu m, the number of the wiring materials 142 may be 10.45 mm to 26.13 mm. However, the present invention is not limited to this, and the pitch of the wiring material 142 and the pitch of the bus bar lines 42b and 44b may have different values.

In this embodiment, the first electrode 42 (or the second electrode 44), the wiring material 142, the electrode region (EA in FIG. 5), and the like are arranged in parallel with the finger lines 42a and 44a in the first direction One direction) and the second direction (the direction parallel to the bus bar line 42b or the wiring member 142). Thus, current flow can be stably implemented. However, the present invention is not limited thereto.

In this embodiment, as described above, in the solar cell 150 having the wiring material 142, the distance between the wiring materials 142 or the pitch between the bus bar lines 42b can be reduced, The resistance can be reduced. Thus, the output can be reduced. However, when the resistance is reduced, the output at a low emission (low light) condition (for example, 0.2 sun) may be significantly lower than the output at a normal condition (for example, 1 sun). That is, the low radiation characteristic may be degraded. In consideration of this, in this embodiment, the shapes of the electrodes 42 and 44 are improved to improve the low radiation characteristic and to exhibit excellent output. This will be described in detail with reference to FIGS. 5 to 7. FIG. Hereinafter, the second electrode 44 will be described in detail with reference to FIGS. 5 and 6, and then an example of the first electrode 42 will be described with reference to FIG.

5 is a partial rear plan view showing the solar cell 150 and the wiring material 142 connected to the solar cell 150 corresponding to part A of FIG. And FIG. 6 is a partial rear plan view showing the solar cell 150 and the wiring material 142 connected thereto according to various modified examples of the present invention. For reference, in FIGS. 5 to 7, the wiring material 142 positioned on the electrodes 42 and 44 of the solar cell 150 is shown by a ruled line.

Referring to FIGS. 5 and 6, in this embodiment, the second electrode 44 includes a plurality of finger lines 44a extending in a first direction and positioned parallel to each other. And a bus bar line 44b extending in a second direction intersecting with the finger line 44a and connected or attached to the wiring material 142. [ Since the bus bar lines 44b can be arranged corresponding to the wiring materials 142, the number, pitch, etc. of the bus bar lines 44b can be directly applied to the description of the number and pitch of the wiring materials 142. [ Hereinafter, the two adjacent bus bar lines 44b in the plurality of bus bar lines 44b are referred to as electrode regions EA, respectively. Since the number of the electrode regions EA is more than one (that is, one of the number of the wiring members 142 is equal to or greater than the number of the wiring members 142) because the wiring members 142 are provided in the present embodiment on the basis of one surface of the solar cell 150 A small number).

The plurality of finger lines 44a may be spaced apart from one another with a uniform width and pitch. Although the finger lines 44a are parallel to the main edges (particularly, the first and second edges 161 and 162) of the solar cell 150 in the first direction, But is not limited thereto.

In this embodiment, the plurality of finger lines 44a have the disconnected portions C1 and C2 in which the first electrode 42 is not formed in a certain region in the electrode region EA. That is, the plurality of finger lines 44a include a plurality of one-line finger lines 441a and 442a of a broken shape. When the single finger fingers 441a and 442a are included in this manner, the resistance (series resistance) increases due to the broken portions C1 and C2, so that the low radiation characteristic can be improved. Since the light can be incident through the disconnection portions C1 and C2, shading loss can be reduced, and the output can be prevented from being lowered while improving the low radiation characteristic. Since there is no finger line 44a at the portion where the disconnection portions C1 and C2 are formed, the manufacturing cost of the finger line 44a can be reduced.

And a plurality of finger lines 44a may include non-line finger lines 440a continuously extending continuously in the electrode area EA corresponding to the two adjacent bus bars 42b. The inclusion of the non-linear finger lines 440a in this manner can reduce the distance by which the carrier reaches the finger line 44a even when the cut line portions C1 and C2 are provided, It is possible to prevent the output from being lowered. However, the present invention is not limited thereto. Therefore, as shown in Fig. 6A, it is also possible to not include the non-linear finger lines 440a. If the non-line finger lines 440a are not provided, the reduction in shading loss and the reduction in manufacturing cost can be maximized by the broken lines C1 and C2.

For example, the ratio of the total number of the plurality of finger lines 44a to the total number of the one-line finger lines 441a and 442a may be 1: 0.3 to 1: 1. If the ratio is less than 1: 0.3, the number of the single finger finger lines 441a and 442a is not sufficient and the effect of the single finger finger lines 441a and 442a may be insufficient. For example, the total number of single finger finger lines 441a, 442a may be equal to or greater than the number of non-finger finger lines 441a, 442a. That is, the ratio of the total number of the plurality of finger lines 44a to the total number of the one-line finger lines 441a and 442a may be 1: 0.5 to 1: 1. Then, it is possible to reduce the shading loss caused by the disconnection portions C1 and C2 and the manufacturing cost reduction effect. However, the present invention is not limited to these ratios.

In this embodiment, the plurality of single-wire finger lines 441a and 442a are connected to the first disconnection line portions 441a and 442b, which are centered at the first position P1 in the first direction (the extending direction of the finger line 44a, (C2) having a center at a second position (P2) different from the first position (P1) in the first direction, the first finger line (441a) having the first finger line Finger line 442a. That is, the center of the first disconnected portion C1 and the center of the second disconnected portion C2 are located at positions displaced from each other in the first direction. Then, the carrier near the first disconnected portion C1 can move to the portion of the second fingerline 442a where the second disconnected portion C2 is not located, or to the non-endored fingerline 440a. Similarly, the carrier in the vicinity of the second disconnected portion C2 can move to the portion of the first fingerline 441a where the first disconnected portion C1 is not located, or to the non-endored fingerline 440a. Thus, even when the cut-off portions C1 and C2 are provided, the movement distance of the carrier can be reduced and the output of the solar cell 100 can be effectively prevented from being lowered.

For example, the present embodiment may not further include a separate finger line having a separate disconnected portion having a center at a position different from the first and second positions P1 and P2. That is, the single finger lines 441a and 442a may include only the first finger line 441a and the second finger line 442a. Thus, the structure of the second electrode 44 can be simplified. Unlike the present embodiment, if a separate disconnected portion is further included, the disconnection portions C1 and C2 are overlapped with each other at different positions, and the carrier moves to a path other than the finger line 44a, . On the other hand, in this embodiment, it is possible to effectively reduce the moving distance of the carrier by a simple structure and to prevent the output from being lowered. However, the present invention is not limited thereto, and may further include a separate finger line having a separate disconnection portion centered at a position different from the first and second positions P1 and P2.

At this time, the first disconnected part C1 and the second disconnected part C2 can be located together in one electrode area EA (that is, between two adjacent bus bar lines 42b) (EA). &Lt; / RTI > Thus, a sufficient number of the first disconnected portion C1 and the second disconnected portion C2 can be formed, thereby reducing the shading loss and the manufacturing cost.

The first finger line 441a, the second finger line 442a and the non-end finger line 440a may have various arrangements.

A plurality of first finger lines 441a and a plurality of second finger lines 442a are provided and the first finger lines 441a and the second finger lines 442a are provided with a plurality of first finger lines 441a and 442a, They can be placed one by one alternately. That is, the first disconnected portion C1 and the second disconnected portion C2 can be positioned with a zigzag arrangement. The first finger line 441a and the second finger line 442a may have the same number in one electrode area EA or may have the same number of first finger lines 441a and the second finger line 442a, May be one. When the first finger line 441a and the second finger line 442a are alternately positioned one by one as described above, when the first disconnected portion C1 and the second disconnected portion C2 are overlapped in the adjacent region, It is possible to prevent an increase in resistance.

In one example, in FIG. 5, the non-end finger line 440a may be positioned one each between the first finger line 441a and the second finger line 442a. That is, the first finger line 441a, the non-end finger finger line 440a, the second finger finger line 442a, and the non-end finger finger line 440a are used as one group, can do. If the non-linear finger lines 440a are positioned between the first finger line 441a and the second finger line 442a as described above, the non-linear finger lines 440a are formed between the first disconnected portion C1 and the second disconnected portion C2. It is possible to prevent the movement distance of the carrier from increasing when the finger line 440a is positioned such that the first disconnected portion C1 and the second disconnected portion C2 are adjacent to or overlapped with each other.

However, the present invention is not limited thereto. 6B and 6C, a pair of the first finger line 441a and the second finger line 442a may be formed as a single pair, Finger lines 440a may be located at least one. More specifically, as shown in FIG. 6 (b), the non-linear finger lines 440a are disposed on both sides with respect to one first finger line 441a and one second finger line 442a, can do. Then, a plurality of groups may be repeatedly arranged as a group of the first finger lines 441a, the second finger lines 442a, and the non-end finger lines 440a which are adjacent to each other. With this arrangement, the number of the non-linear finger lines 440a can be reduced, thereby further reducing the material cost and increasing the resistance as desired. At this time, a plurality of non-linear finger lines 440a may be positioned between the pair of first finger lines 441a and the second finger lines 442a. 6 (c), the first finger line 441a, the second finger line 442a, and the plurality of non-end finger lines 440a which are adjacent to each other are grouped into a plurality of groups Can be repeatedly positioned. If a plurality of non-linear finger lines 440a are provided between a pair of the first finger line 441a and the second finger line 442a, the movement distance of the carrier can be reduced. Alternatively, the number of the non-end finger lines 440a positioned between the pair of first finger lines 441a and the second finger lines 442a can be freely selected and arranged in one or a plurality of. Various other variations are possible.

5, the first position P1, which is the center of the first disconnected portion C1, and the second position P2, which is the center of the second disconnected portion C2 in the present embodiment, And may be positioned symmetrically with respect to each other in the first direction. That is, the first distance L1 and the second position P2 spaced apart from the first bus bar line 441b located at one side of the electrode area EA in the first position P1 are located on the other side of the electrode area EA The second distance L2 spaced from the second bus bar line 442b located at the second bus bar line 442b may be the same or similar to each other. That is, the first distance L1 and the second distance L2 may have a deviation within 20%. By disposing the first disconnected portion C1 and the second disconnected portion C2 symmetrically, the first disconnected portion C1 and the second disconnected portion C2 can be effectively dispersed to minimize the movement distance of the carrier .

The first position P1 or the second position P2 may be spaced apart by a predetermined distance from the bus bar line 44b. At this time, the first position P1 or the second position P2 is biased toward the bus bar line 44b away from the center, i.e., the center, in the electrode area EA in the first direction . More specifically, the first position P1 is biased toward the first bus bar line 441b from the center of the electrode area EA in the first direction, and the second position P2 is positioned biased toward the electrode area (EA) toward the second bus bar line 442b. That is, the first position P1 may be positioned on one side and the second position P2 may be positioned on the other side with respect to the center of the electrode area EA in the first direction. As a result, it is possible to prevent a problem that may occur when the first and second disconnection portions C1 and C2 are shifted to one side while effectively shifting the first position P1 and the second position P2.

For example, the length of each electrode area EA in the first direction (more specifically, the pitch between the first bus bar line 441b and the second bus bar line 442b) L: The ratio of the first distance L1 between the second bus bar line 421b and the first position P1 or the distance L2 between the second bus bar line 424b and the second position P2 is 1: : 0.45 (for example, 1: 0.20 to 1: 0.35). In this range, the first position P1 and the second position P2 can be positioned sufficiently shifted, and the moving distance of the carrier can be minimized. However, the present invention is not limited thereto.

The ratio (L: CL1 or L: CL2) of the length (L) of each electrode area (EA): the length CL1 of the first disconnected part C1 or the length CL2 of the second disconnected part C2 1: 0.08 to 1: 0.45. At this time, the length L of the electrode area EA, the length CL1 of the first disconnected part C1, and the length CL2 of the second disconnected part C2 can be measured in the first direction. If the ratio (L: CL1 or L: CL2) is less than 1: 0.08, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 is not sufficient, C1, C2) may not be sufficient. If the ratio (L: CL1 or L: CL2) exceeds 1: 0.45, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 becomes large, Even if the two disconnection portions C1 and C2 are arranged to be shifted from each other, the carrier can flow to a portion other than the finger line 44a.

Alternatively, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 may be 0.3 to 3 times the pitch of the plurality of finger lines 44a. If the ratio is less than 0.3, the length L1 of the first disconnected portion C1 or the length L2 of the second disconnected portion C2 is not sufficient and the effect of the disconnected portions C1 and C2 is not sufficient . If the ratio exceeds 3 times, the resistance of the second electrode 44 may become excessively high because the length CL1 of the first disconnected part C1 or the length CL2 of the second disconnected part C2 is large.

Alternatively, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 may be 1 mm to 5 mm. The length L1 of the first disconnected portion C1 or the length L2 of the second disconnected portion C2 is set to be less than 1 mm when the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 is less than 1 mm, The effect of the disconnection portions C1 and C2 may not be sufficient. If the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 exceeds 5 mm, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 The length CL2 of the second electrode 44 is large and the resistance of the second electrode 44 can be excessively high.

Alternatively, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 may be larger than the width of the wiring material 142. [ This is because in this embodiment, the width CL2 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 is set to a predetermined value or more . For example, the width of the wiring material 142: the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 may be 1: 2 to 1:20. If the ratio is less than 1: 2, the length CL1 of the first disconnected part C1 or the length CL2 of the second disconnected part C2 is not sufficient and the first or second disconnected part C1, May not be sufficient. If the ratio exceeds 1:20, the length CL1 of the first disconnected portion C1 or the length CL2 of the second disconnected portion C2 becomes excessively large, so that the resistance of the second electrode 44 can be greatly increased have. Here, the width of the wiring material 142: the length CL1 of the first disconnected part C1 or the length CL2 of the second disconnected part C2 may be 1: 4 to 1:10. In this range, it is possible to prevent the resistance of the second electrode 44 from increasing greatly while maximizing the effect of the first or second disconnected part C1 or C2.

However, the present invention is not limited to this, and the lengths CL1 and CL2 of the first and second disconnected portions C1 and C2 may have different values.

For example, the length CL1 of the first disconnected portion C1 and the length CL2 of the second disconnected portion C2 may be the same or similar. For example, the length CL1 of the first disconnected portion C1 and the length CL2 of the second disconnected portion C2 may be within 20%. When the length CL1 of the first disconnected portion C1 and the length CL2 of the second disconnected portion C2 are equal or similar to each other, the first disconnected portion C1 and the second disconnected portion C2 And can be uniformly dispersed. However, the present invention is not limited thereto, and the lengths CL1 and CL2 of the first and second disconnected portions C1 and C2 can be variously changed.

If the first disconnected portion C1 and the second disconnected portion C2 are located symmetrically with similar shapes or lengths CL1 and CL2 as in the present embodiment, the resistances are effectively dispersed to uniformly distribute the resistances can do. The efficiency of the solar cell 150 can be easily analyzed and the manufacturing process can be simplified to improve the productivity. In addition, uniformity of the solar cell 150 can be improved.

In FIG. 5, the first disconnected part C1 and the second disconnected part C2 are located apart from each other in the first direction. That is, the end portion of the first disconnected portion C1 and the end portion of the second disconnected portion C2, which are adjacent to each other, can have the third distance L3 which is constant in the first direction. Since the first disconnected portion C1 and the second disconnected portion C2 are spaced from each other, the first disconnected portion C1 and the second disconnected portion C2 can be effectively dispersed, and the first disconnected portion C1 and the second disconnected portion C2 can be effectively dispersed, Carriers located in the portions C1 and C2 can reach the second or first finger lines 442a and 441a or the non-line finger lines 440a, which are located adjacent to each other. In particular, as shown in Figs. 6A to 6C, the first finger line 441a and the second finger line 442a, which are positioned adjacent to each other without sandwiching the non-line finger line 440a, The carrier located at the first or second disconnected part C1 or C2 can reach the second or first finger line 442a or 441a with a short travel distance.

However, the present invention is not limited thereto. Therefore, as a modified example, the first disconnected portion C1 and the second disconnected portion C2 may be positioned so as to partially overlap in the first direction, as shown in Fig. 6 (d). The end of the first disconnected part C1 adjacent to the second bus bar line 442b is connected to the second bus bar line 442b more than the end of the second disconnected part C2 adjacent to the first bus bar line 441b, As shown in FIG. Accordingly, the first disconnected portion C1 and the second disconnected portion C2 can be overlapped by a predetermined fourth distance L4 in the first direction. Since the first disconnected portion C1 and the second disconnected portion C2 can have a sufficient length when the first disconnected portion C1 and the second disconnected portion C2 are overlapped in the first direction as described above, Can be reduced and the resistance can be increased as desired. The first finger line 441a and the second finger line 442a may be separated from each other by the first finger line 441a and the second finger line 442a because the carrier may flow in an undesired direction at a portion where the first disconnected portion C1 and the second disconnected portion C2 overlap. And a non-linear finger line 440a may be positioned between each of the non-linear finger lines 440a. However, the present invention is not limited thereto and various arrangements are possible.

For example, the ratio of the fourth distance L4 to the length L of the electrode area EA may be 50% or less (25% or less). If the ratio exceeds 50%, the fourth distance L4 at which the first disconnected portion C1 and the second disconnected portion C2 overlap may be large, and it may be difficult to collect the carriers effectively. Considering the collection efficiency of the carrier, the above ratio may be 25% or less. However, the present invention is not limited thereto, and the ratios may have different values.

Referring again to FIG. 5, in this embodiment, the first disconnected portion C1 and the second disconnected portion C2 may be spaced apart from the first and second bus bar lines 441b and 442b. That is, the first finger line 441a includes a first portion R1 positioned between the first disconnected portion C1 and the first bus bar line 441b and having a relatively short length, a first disconnected portion C1 And a second portion R2 located between the second bus bar line 441a and the second bus bar line 441b and having a relatively long length. Similarly, the second finger line 442a includes a third portion R3 positioned between the second disconnected portion C2 and the first bus bar line 441b and having a relatively long length, And a fourth portion R4 positioned between the first bus bar line C2 and the second bus bar line 442b and having a relatively short length. As such, if the first and second finger lines 441a and 442a include the first and second portions R1 and R2 or the third and fourth portions R3 and R4, respectively, the finger line 44a and the bus The finger line 44a and the bus bar line 44b can be smoothly connected even if an align miss occurs when the bar line 44b is formed by another material or another process. Even if an alignment error occurs when the bus bar line 44b and the wiring member 142 are aligned, the wiring member 142 and the finger line 44a (or the first portion R1 or the fourth portion R4) ) Can be stably connected.

The ratio of the length of the first part R1 to the length L of the electrode area EA (or the ratio of the length of the fourth part R4 to the length L of the electrode area EA) May be 5% to 20% (e.g., 10% to 20%). It is possible to sufficiently secure the lengths of the disconnection portions C1 and C2 while effectively coping with the alignment error within this range. However, the present invention is not limited thereto, and the ratio may have various values.

However, the present invention is not limited thereto. 6E, the first disconnected line C1 is located adjacent to the first bus bar line 441b and the first finger line 441b is connected to the first portion R1 (R1) May be omitted. Similarly, the second disconnected line portion C2 may be located adjacent to the second bus bar line 442b, and the second finger line 442a may not have the fourth portion R4. This is because when the finger line 44a and the bus bar line 44b are formed by the same process, the problem caused by the alignment error does not need to be considered.

In the above description and drawings, the first and second finger lines 441a and 442a in the plurality of electrode regions EA are repeatedly arranged with the same arrangement, shape, and the like. As a result, the broken portions C1 and C2 can be effectively arranged by regularly arranging the broken portions C1 and C2. As a result, the second electrode 44 having the disconnected portions C1 and C2 can be formed by a simple manufacturing process or the like, and the carriers can be uniformly collected as a whole. However, the present invention is not limited thereto. The arrangement and shape of the first and second finger lines 441a and 442a may be applied to different electrode regions EA.

In one example, the finger line 44a of the second electrode 44 may have a width of 35 um to 120 um. The finger line 44a of the second electrode 44 may have a pitch of 1.2 mm to 2.8 mm and the number of the finger lines 44a in the direction crossing the finger line 44a may be 55 to 130 have. These widths and pitches can be formed by easy process conditions and are limited to effectively collect current generated by photoelectric conversion while minimizing shading losses due to finger lines 44a. The thickness of such a finger line 44a can be in a range that can be easily formed in the process and can have a desired resistivity. However, the present invention is not limited thereto, and the width, pitch and the like of the finger line 44a may be variously changed according to changes in process conditions, the size of the solar cell 150, the material of the finger line 44a, and the like.

At this time, the width of the wiring material 142 may be smaller than the pitch of the finger lines 44a, and may be larger than the width of the finger lines 44a. However, the present invention is not limited thereto and various modifications are possible.

In one example, the bus bar line 44b may be continuously formed from the portion adjacent to the first edge 161 to the portion adjacent to the second edge 162 in the electrode region EA. As described above, the bus bar line 44b may be positioned so as to correspond to the portion where the wiring material 142 for connection with the neighboring solar cell 150 is located. These bus bar lines 44b may be provided so as to correspond one-to-one with the wiring material 142. [ Accordingly, in this embodiment, the bus bar lines 44b may be provided in the same number as that of the wiring material 142 on the basis of one surface of the solar cell 150. [

The bus bar line 44b includes a long line portion 441 having a relatively narrow width along the direction in which the wiring member 142 is connected in the electrode region EA and a long line portion 441 having a width wider than the line portion 441 And a pad portion 442 for increasing a connection area with the lead wiring material 142. It is possible to minimize the area for blocking the light incident on the solar cell 150 by the narrow line portion 441 and to prevent the wiring member 142 and the bus bar line 44b The adhesion force can be improved and the contact resistance can be reduced. The pad portion 442 has a width larger than that of the line portion 441 and is a region to which the wiring material 142 is substantially attached. The wiring member 142 may be attached to the line portion 441 or the wiring member 142 may be placed on the line portion 441 without the wiring member 142 being attached to the line portion 441. [

The width of the pad portion 442 measured in the first direction may be greater than the width of the line portion 441 and the finger line 44a.

The line portion 441 of the bus bar line 44b is provided so as to correspond to the wiring material 142 in this embodiment. More specifically, a bus bar electrode having a width much larger than that of the finger line 44a corresponding to the wiring member 142 is disposed. In this embodiment, the width of the bus bar line 44b The line portion 441 is located. In this embodiment, the line portion 441 may connect a plurality of finger lines 44a to provide a path through which the carrier can bypass when some finger lines 44a are broken.

Herein, the bus bar electrode refers to an electrode portion formed in a direction crossing the finger line to correspond to the ribbon and having a width of 12 times or more (usually 15 times or more) the width of the finger line. Since the bus bar electrode has a relatively large width, it is usually formed by two or three electrodes. The line portion 441 of the bus bar line 44b in this embodiment is formed in a direction intersecting with the finger line 44a so as to correspond to the wiring material 142 and has a width of 10 times or less the width of the finger line 44a Electrode portion having a width can be referred to.

In one example, the width of the line portion 441 may be 0.5 to 10 times the width of the finger line 44a. If the ratio is less than 0.5 times, the width of the line portion 441 is reduced and the effect of the line portion 441 may not be sufficient. If the ratio exceeds 10 times, the width of the line portion 441 becomes large and the light loss can be increased. In particular, since the number of the wiring members 142 is large in the present embodiment, the number of the line portions 441 is also increased, and the optical loss can be increased. More specifically, the width of the line portion 441 may be 0.5 to 7 times the width of the finger line 44a. The above ratio can be reduced to 7 times or less to further reduce the optical loss. In one example, referring to the light loss, the width of the line portion 441 may be 0.5 to 4 times the width of the finger line 44a. More specifically, the width of the line portion 441 may be 0.5 to 2 times the width of the finger line 44a. In this range, the efficiency of the solar cell 150 can be greatly improved.

Alternatively, the width of the line portion 441 may be equal to or less than the width of the wiring material 142. The width or area of the line member 441 contacting the line member 441 at the lower portion of the wiring member 142 is not large when the wiring member 142 has a circular shape, an elliptical shape, or a rounded shape, Or less than, the width of the < / RTI > By reducing the width of the line portion 441 in this way, the area of the second electrode 44 can be reduced to reduce the material cost of the second electrode 44.

For example, the ratio of the width of the wiring member 142: the width of the line portion 441 may be 1: 0.07 to 1: 1. If the ratio is less than 1: 0.07, the width of the line portion 441 is too small and the electrical characteristics and the like may be deteriorated. If the ratio is more than 1: 1, the contact property with the line part 441 is not greatly improved, but the area of the second electrode 44 is increased only, thereby increasing the optical loss and increasing the material cost. For example, in consideration of optical loss, material cost, etc., the ratio may be 1: 0.1 to 1: 0.5 (more specifically, 1: 0.1 to 1: 0.3).

Alternatively, the width of the line portion 441 may be between 35 [mu] m and 350 [mu] m. If the width of the line portion 441 is less than 35 mu m, the width of the line portion 441 is too small and the electrical characteristics and the like may be deteriorated. If the width of the line portion 441 exceeds 350 μm, the contact property with the line portion 441 and the like are not greatly improved, but only the area of the second electrode 44 is increased to increase the optical loss and increase the material cost . For example, considering the light loss, material cost, and the like, the width of the line portion 441 may be 35um to 200um (more specifically, 35um to 120um).

However, the present invention is not limited thereto. Accordingly, the width of the line portion 441 can be variously modified within a range that minimizes the shading loss while efficiently transmitting the current generated by the photoelectric conversion.

The width of the pad portion 442 is larger than the width of the line portion 441 and may be equal to or larger than the width of the wiring material 142. [ Since the pad portion 442 is a portion for increasing the contact area with the wiring material 142 to improve the adhesion with the wiring material 142, the pad portion 442 has a width larger than that of the line portion 441, will be.

For example, the ratio of the width of the wiring material 142 to the width of the pad portion 442 may be 1: 1 to 1: 5. If the ratio is less than 1: 1, the width of the pad portion 442 is not sufficient and the adhesion force between the pad portion 442 and the wiring material 142 may not be sufficient. If the ratio is more than 1: 5, the area of light loss by the pad portion 442 is increased and the shading loss may be large. The ratio may be 1: 2 to 1: 4 (more specifically, 1: 2.5 to 1: 4).

Or, as an example, the width of the pad portion 442 may be 0.25 mm to 2.5 mm. If the width of the pad portion 442 is less than 0.25 mm, the contact area with the wiring material 142 is not sufficient and the adhesion force between the pad portion 442 and the wiring material 142 may not be sufficient. If the width of the pad portion 442 exceeds 2.5 mm, the area where light is lost by the pad portion 442 is increased and the shading loss may be large. For example, the width of the pad portion 442 may be 0.8 mm to 1.5 mm.

The length of the pad portion 442 may be greater than the width of the finger line 44a. For example, the pad portion 442 may have a length of 0.035 mm to 30 mm. If the length of the pad portion 442 is less than 0.035 mm, the contact area between the pad portion 442 and the wiring member 142 may be insufficient and the adhesion force between the pad portion 442 and the wiring member 142 may not be sufficient. If the length of the pad portion 442 exceeds 30 mm, the area where the light is lost by the pad portion 442 is increased and the shading loss may be large.

Or, as an example, the ratio of the width of the finger line 44a to the length of the pad portion 442 may be 1: 1.1 to 1:20. The adhesion area between the pad portion 442 and the wiring material 142 can be increased by increasing the area of attachment of the pad portion 442 and the wiring material 142 within this range.

Alternatively, for example, the ratio of the width of the wiring member 142 to the length of the pad portion 442 may be 1: 1 to 1:10. If the ratio is less than 1: 1, the length of the pad portion 442 is not sufficient and the adhesion force between the pad portion 442 and the wiring material 142 may not be sufficient. If the ratio exceeds 1:10, the area of light loss by the pad portion 442 increases and the shading loss may be large. Considering the adhesion, light loss and the like, the ratio may be 1: 3 to 1: 6.

In one bus bar line 44b, the pad portions 442 may be arranged in a number of 6 to 24 (for example, 12 to 22). The plurality of pad portions 442 may be spaced apart. In one example, it may be positioned one by one for every two to ten finger lines 44a. According to this, the portion where the area of the bonding of the bus bar line 44b and the wiring member 142 increases is regularly provided, so that the bonding force between the bus bar line 44b and the wiring member 142 can be improved. Alternatively, the plurality of pad portions 442 may be disposed such that the distance between the two pad portions 442 is different from each other. In particular, the pad portion 442 can be arranged at a high density at the end of the bus bar line 44b where a larger force is applied than the other portion (i.e., the central portion of the bus bar line 44b). Various other variations are possible.

In the above description, the second electrode 44 is mainly described with reference to FIGS. 5 and 6. FIG. The first electrode 42 may include a finger line 42a and a bus bar line 42b corresponding to the finger line 44a and the bus bar line 44b of the second electrode 44, respectively. The contents of the finger line 44a and the bus bar line 44b of the second electrode 44 can be applied to the finger line 42a and the bus bar line 42b of the first electrode 42 as they are. Similarly to the finger line 44a of the second electrode 44, the finger line 42a of the first electrode 42 may include a single finger finger line 421a and a non-finger finger line 420a. However, since the shape, arrangement, and the like of the single finger finger line 421a having the single finger portion C3 in the first electrode 42 are different from those of the single finger finger lines 441a and 442a of the second electrode 44, This will be described in more detail with reference to FIG.

7 is a partial front plan view showing a solar cell 150 and a wiring material 142 connected thereto corresponding to the portion A in Fig.

Referring to FIG. 7, in this embodiment, the single finger line 421a of the first electrode 42 includes only the third disconnected part C3 having a center at one position. If the first electrode 42 located on the front surface has a single line finger line having a center line at different positions, the appearance may be degraded. In consideration of this, in the present embodiment, the third disconnected part C3 located only at one position can be provided to improve the appearance.

For example, the center of the third disconnected part C3 may be located at the center of the electrode area EA in the first direction. Accordingly, the movement distance according to the position of the carrier can be minimized, and regularity can be imparted to improve the appearance.

The length CL3 of the third disconnected part C3 may be equal to or less than the length CL1 of the first disconnected part C1 or the length CL2 of the second disconnected part C2. Accordingly, the first electrode 42, which is located on the front surface of the solar cell 150 and is connected to the first conductive region 20 functioning as an emitter region, can effectively collect carriers.

For example, the length CL3 of the third disconnected part C3 may be 1 mm to 5 mm (for example, 1 mm to 3.5 mm). If the length CL3 of the third disconnected portion C3 is less than 1 mm, the length CL3 of the third disconnected portion C3 may not be sufficient and the effects of reducing the shading loss and reducing the manufacturing cost may not be sufficient. When the length CL3 of the third disconnected part C3 exceeds 5 mm, the length CL3 of the third disconnected part C3 is large and the resistance of the first electrode 42 can be excessively high. Considering the resistance of the first electrode 42, the length CL3 of the third disconnected portion C may be 1 mm to 3.5 mm.

Alternatively, the ratio of the length L of each electrode area EA to the length CL of the third disconnected part C3 may be 1: 0.08 to 1: 0.45 (for example, 1: 0.08 to 1: 0.30) have. At this time, the length L of the electrode area EA and the length CL3 of the third disconnected part C3 can be measured in the first direction. If the ratio L: CL3 is less than 1: 0.08, the length CL3 of the third disconnected part C3 is not sufficient and the effect of the third disconnected part C3 may not be sufficient. If the ratio (L: CL3) exceeds 1: 0.45, the resistance of the first electrode 42 can be increased. Considering the resistance of the first electrode 42, the ratio may be 1: 0.08 to 1: 0.30.

Alternatively, the length CL3 of the third disconnected part C3 may be 0.3 to 3 times (for example, 0.3 to 2 times) the pitch of the plurality of finger lines 44a. If the ratio is less than 0.3 times, the length CL3 of the third disconnected portion C3 is not sufficient and the effect of the third disconnected portion C3 may not be sufficient. If the ratio exceeds 3 times, the length L3 of the third disconnected part C3 becomes large, and the resistance of the first electrode 42 can be excessively high. Considering the resistance of the first electrode 42, the ratio may be 0.3 to 2 times.

However, the present invention is not limited thereto, and the length CL3 of the third disconnected part C3 may have various values.

In the drawing, the single finger finger line 421a and the non-finger finger line 420a are alternately arranged one by one. However, the present invention is not limited thereto, and the arrangement of the single finger finger line 421a and the non-finger finger line 420a may be variously changed. Therefore, the non-line finger line 420a may not be provided. Alternatively, the number of the single finger finger lines 421a and the number of the non-single finger finger lines 420a forming a group to be repeated may have various values.

In FIG. 7, the bus bar line 42b includes the line portion 421 and the pad portion 422, but the present invention is not limited thereto.

7 and the above description, it is illustrated that the first electrode 42 has a shape different from that of the second electrode 44. That is, the position of the third disconnected part C3 of the single finger line 421a of the first electrode 42 is different from the position of the second electrode 44 with respect to the first and second disconnected parts C1 and C2 have. The length CL3 of the third disconnected part C3 of the disconnected finger line 421a of the first electrode 42 is smaller than the length CL3 of the first disconnected finger line 422a of the second electrode 44, May be equal to or smaller than the lengths (CL1, CL2) of the first and second plates (C1, C2). However, the present invention is not limited thereto, and the first electrode 42 may have the same shape as the second electrode 44. Alternatively, at least one of the position and the length CL3 of the third disconnected part C3 of the single finger line 421a of the first electrode 42 may correspond to the single finger line 441a of the second electrode 44 corresponding thereto And the lengths CL1 and CL2 of the first or second disconnection portions C1 and C2 of the first and second disconnection portions C1 and C2. Various other variations are possible.

According to the present embodiment, at least one (e.g., the second electrode 44) of the first and second electrodes 42 and 44 is provided with a single finger line 441a and 442a to minimize shading loss, Can be saved. At this time, even if the center of the first disconnected portion C1 and the center of the second disconnected portion C2 are located so as to be shifted from each other and the first and second disconnected portions C1 and C2 are provided, the movement distance of the carrier can be minimized have. Thus, it is possible to minimize the shading loss and minimize the moving distance of the carrier, thereby preventing the output of the solar cell panel 100 from being degraded, while increasing the resistance by the disconnection portions C1 and C2 to improve the low radiation characteristic. Therefore, the solar cell 150 or the solar cell panel 100 including the solar cell 150 can have excellent low-emission characteristics and high output.

Features, structures, effects and the like according to the above-described embodiments are included in at least one embodiment of the present invention, and the present invention is not limited to only one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

100: Solar panel
150: Solar cell
160: semiconductor substrate
10: Base area
20: first conductivity type region
30: second conductivity type region
42: first electrode
44: Second electrode
44a: Finger line
44b: bus bar line
440a: Non-line finger line
441a: first finger line
442a: second finger line

Claims

A semiconductor substrate;
A conductive type region located on or above the semiconductor substrate; And
And an electrode coupled to the conductive region,
Wherein the electrode comprises a plurality of finger lines extending in a first direction and
And a plurality of bus bar lines connected in a second direction intersecting with the first direction,
Wherein the plurality of finger lines are formed to extend between neighboring bus bar lines of the plurality of bus bar lines, and a first disconnecting line having a first interval in the first direction is connected to a first finger line And a second finger line having a second disconnected portion at a second position having a second gap different from the first gap in the first direction,
The lengths of the first and second disconnected portions are respectively shorter than the lengths of the first finger line and the second finger line formed between the bus bar lines,
Wherein the first position and the second position are located apart from each other at different positions where the center portions do not overlap with each other.

The method according to claim 1,
The first position and the second position being symmetrical with respect to each other in the first direction.

The method according to claim 1,
A plurality of first finger lines are provided,
A plurality of second finger lines are provided,
Wherein the first finger line and the second finger line are alternately positioned one by one in a second direction intersecting the first direction when the finger line having the first or second disconnected portion is defined as a reference.

The method according to claim 1,
The length of the first disconnected portion or the second disconnected portion is 0.3 to 3 times the pitch of the plurality of finger lines;
The length of the first disconnected part or the second disconnected part is 1 mm to 5 mm;
And a plurality of bus bar lines formed in a second direction intersecting with the first direction and including first and second bus bar lines adjacent to each other, Wherein the ratio of the length of the first disconnected portion or the length of the second disconnected portion is 1: 0.08 to 1: 0.45.

The method according to claim 1,
And a plurality of bus bar lines formed in a second direction intersecting the first direction and including first and second bus bar lines adjacent to each other,
Wherein the first position or the second position in one electrode region defined by the first and second bus bar lines deviates from the center of the one electrode region in the first direction.

The method according to claim 1,
And a plurality of bus bar lines formed in a second direction intersecting the first direction and including first and second bus bar lines adjacent to each other,
A length of one electrode region defined by the first and second bus bar lines: a first distance between the first bus bar line and the first position or a length of the electrode region: And the ratio of the second distance between the second positions is 1: 0.20 to 1: 0.35.

delete

The method according to claim 1,
Wherein the first disconnected part and the second disconnected part are located so as to partially overlap with each other in the first direction.

9. The method of claim 8,
And a plurality of bus bar lines formed in a second direction intersecting the first direction and including first and second bus bar lines adjacent to each other,
Wherein a ratio of a length in which the first disconnection portion overlaps with the second disconnection portion in the first direction is 50% or less with respect to a length of one electrode region defined by the first and second bus bar lines.

The method according to claim 1,
And a plurality of bus bar lines formed in a second direction crossing the first direction,
Wherein the first disconnected portion or the second disconnected portion is located apart from the bus bar line.

The method according to claim 1,
And a plurality of bus bar lines formed in a second direction crossing the first direction,
The number of the bus bar lines is 6 to 33,
Wherein the width of the bus bar line is 0.5 to 10 times the width of the finger line.

The method according to claim 1,
And a plurality of bus bar lines formed in a second direction intersecting the first direction and including first and second bus bar lines adjacent to each other,
The first finger line includes a first portion located adjacent to the first bus bar line and a second portion located adjacent to the second bus bar line and longer than the first portion,
Wherein a length ratio of the first portion to a length of one electrode region in the first direction is 5% to 20%.

The method according to claim 1,
Wherein the plurality of finger lines further include non-linear finger lines extending continuously.

14. The method of claim 13,
Wherein the non-end finger lines are located respectively between the plurality of first finger lines and the plurality of second finger lines;
One of the first finger lines and the second finger lines is paired so that at least one of the non-linear finger lines is located between the pair.

14. The method of claim 13,
Wherein a finger line having the first or second disconnected portion is provided equal to or more than the non-tapped finger line.

The method according to claim 1,
Another conductive type region having a conductivity type opposite to the conductive type region; And
A second electrode coupled to said another conductive region and comprising a plurality of finger lines formed in a first direction and parallel to each other,
Further comprising:
Wherein the plurality of finger lines of the another electrode are centered in a third position different from the first position and the second position in the first direction or have different lengths from the first or the second cut- And a third disconnection portion of the branch.

A plurality of solar cells including first and second solar cells located at least adjacent to each other; And
And a plurality of wiring members connecting the first solar cell and the second solar cell and including rounded portions,
Each of the solar cells includes: a semiconductor substrate; A conductive type region located on or above the semiconductor substrate; And an electrode coupled to the conductive region,
Wherein the electrode comprises a plurality of finger lines extending in a first direction and
And a plurality of bus bar lines connected in a second direction intersecting with the first direction,
Wherein the plurality of finger lines are formed to extend between neighboring bus bar lines of the plurality of bus bar lines, and a first disconnecting line having a first interval in the first direction is connected to a first finger line And a second finger line having a second disconnected portion at a second position having a second gap different from the first gap in the first direction,
The lengths of the first and second disconnected portions are respectively shorter than the lengths of the first finger line and the second finger line formed between the bus bar lines,
Wherein the first position and the second position are located apart from each other at different positions where the center portions do not overlap with each other.

18. The method of claim 17,
The number of the plurality of wiring materials is 6 to 33,
And each of the plurality of wiring materials has a width of 250um to 500um.

18. The method of claim 17,
Wherein a ratio of a length of one electrode region defined by two wiring members adjacent to each other in the plurality of wiring materials: a length of the first disconnected portion or a length of the second disconnected portion is 1: 0.08 to 1: 0.45.

18. The method of claim 17,
The width of the wiring material: the ratio of the length of the first disconnected portion or the length of the second disconnected portion is 1: 2 to 1:20.