KR101680388B1

KR101680388B1 - Solar cell module

Info

Publication number: KR101680388B1
Application number: KR1020110000378A
Authority: KR
Inventors: 장재원; 진윤실; 심구환; 최영호
Original assignee: 엘지전자 주식회사
Priority date: 2011-01-04
Filing date: 2011-01-04
Publication date: 2016-11-28
Also published as: KR20120079213A

Abstract

A solar cell module comprising: a plurality of strings formed by electrically connecting a plurality of solar cells arranged in a row, the solar cell module comprising: a first interconnector electrically connecting two solar cells arranged in the same string; And at least one second interconnector electrically connecting two solar cells arranged in different strings, wherein the first interconnector and the second interconnector are disposed in a space between solar cells electrically connected to each other, And a solar cell module.

Description

Solar cell module {SOLAR CELL MODULE}

The present invention relates to a solar cell module having a plurality of solar cells.

With the recent depletion of existing energy sources such as petroleum and coal, interest in alternative energy to replace them is increasing, and solar cells are attracting attention.

A solar cell converts solar energy into electric energy using the photoelectric conversion effect, and a solar cell produces a small power of about several V or less. Therefore, in order to obtain a desired output, a plurality of solar cells are connected in series or in parallel, and then a waterproof solar cell module is used.

In order to output power generated by a solar cell to the outside in a solar cell module, a conductor such as an interconnector connected to a positive electrode and a negative electrode of the solar cell is connected to a lead wire and taken out to the outside of the solar cell module, And a current is extracted through a power line of the terminal box.

In the solar cell module having such a configuration, the lead wire is disposed outside the region where the solar cell is installed in the solar cell panel. Therefore, since an area for arranging the lead wires is required, an ineffective part that does not contribute to power generation is secured in the solar cell panel, and the size of the solar cell panel, that is, the solar cell module, increases due to the invalid part .

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solar cell module capable of reducing the size of a solar cell module by reducing an invalid portion.

A solar cell module according to an embodiment of the present invention includes a plurality of strings formed by electrically connecting a plurality of solar cells arranged in a row, wherein the solar cell module includes two solar cells arranged in the same string, A first inter connecter electrically connecting the first inter connecter and the second inter connecter; And at least one second interconnector electrically connecting two solar cells arranged in different strings, wherein the first interconnector and the second interconnector are disposed in a space between solar cells electrically connected to each other, do.

The first interconnector is located in the same first direction as the string and the second inter connecter is located in the second direction that intersects the first direction.

The first inter connecter may be formed of a flexible printed circuit (FPC) or a strip-shaped ribbon, and the second inter-connector may be formed of a flexible printed circuit (FPC) or a strip-shaped ribbon.

The two solar cells electrically connected by the second inter connecter may be formed in the same structure.

For example, two solar cells electrically connected by the second interconnector may include a first electrode located on one side of the substrate and a second electrode located on the other side of the substrate, And a plurality of front electrode current collectors positioned in a direction intersecting with the plurality of front electrodes and the front electrodes extending in one direction and the second electrode may be a rear electrode positioned on the entire other surface of the substrate .

At this time, one of the two solar cells electrically connected by the second interconnector is arranged so that the front electrode current collector is located in the second direction, and the other solar cell is connected to the front electrode current collector May be arranged in the first direction.

In another example, two solar cells electrically connected by the second interconnector each include a first electrode located on one side of the substrate and a second electrode located on the other side of the substrate, And a plurality of front electrode current collectors positioned in a direction intersecting with the plurality of front electrodes and the front electrodes extending in parallel to each other in one direction and the plurality of rear electrodes positioned in a direction parallel to the front electrodes And a rear electrode electrically connected to current collectors and collectors for the rear electrode.

At this time, any one of the two solar cells electrically connected by the second interconnector is arranged such that the front electrode current collector is located in the first direction, and the other solar cell is arranged in the front electrode house All of which are arranged in the second direction.

Alternatively, two solar cells electrically connected by the second interconnector may be formed in different structures.

In this case, one of the two solar cells electrically connected by the second inter connecter includes a first electrode located on one side of the substrate and a second electrode located on the other side of the substrate, One electrode includes a plurality of front electrodes extending in parallel in one direction and a plurality of front electrode current collectors positioned in a direction crossing the front electrodes and the second electrode is a rear electrode positioned on the entire rear surface of the substrate .

Alternatively, one of the two solar cells electrically connected by the second interconnector may include a first electrode located on one side of the substrate and a second electrode located on the other side of the substrate, One electrode includes a plurality of front electrodes extending in parallel in one direction and a plurality of front electrode current collectors positioned in a direction crossing the front electrodes and the second electrode comprises a plurality of And a back electrode electrically connected to the current collector for the back electrode and the current collector for the back electrode.

According to this aspect, the second inter connecters electrically connecting the two solar cells arranged in different strings are located in the space between the solar cells.

Therefore, in order to electrically connect the two solar cells arranged in different strings, the ineffective space portions provided on the upper and lower sides of the solar cell module can be reduced to a large extent as compared with the conventional solar cell module.

For example, when solar cells arranged in the same string are electrically connected to each other by using ribbon-shaped ribbons and two solar cells arranged in different strings are connected by using ribbon-shaped ribbons or lead wires, An invalid space portion having a width of about 9 cm should be formed on the upper side and the lower side of the module. However, the solar cell module of the present embodiment can form the invalid space portion with a width of about 1 cm each.

Further, when the first inter connector and the second inter connecter are formed of a flexible printed circuit, the defective connection between the solar cells can be reduced due to the superior ductility characteristics compared with the conventional ribbon.

1 is a plan view of a solar cell module according to a first embodiment of the present invention.
FIG. 2 is a perspective view of a main part of a solar cell according to a first embodiment of the present invention. FIG.
3 is a perspective view of a main part of a solar cell according to a second embodiment of the present invention.
4 is a perspective view of a main part of a solar cell according to a third embodiment of the present invention.
5 is a plan view of a solar cell module according to a second embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention in the drawings, portions not related to the description are omitted, and like reference numerals are given to similar portions throughout the specification.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. When a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case directly above another portion but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Embodiments of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a plan view of a solar cell module according to a first embodiment of the present invention, and FIGS. 2 to 4 are perspective views of main parts according to first to third embodiments of the solar cell shown in FIG.

Referring to the drawings, a solar cell module according to an embodiment of the present invention includes a plurality of solar cells 100.

Although not shown, the solar cell module includes a protective film (EVA: Ethylene Vinyl Acetate) for protecting the solar cells 100, a transparent member disposed on the protective film toward the light receiving surface of the solar cells 100, A back sheet of an opaque material, a frame for housing the components integrated by the lamination process, and a junction box for collecting power produced by the solar cells.

The back sheet prevents the penetration of moisture from the back surface of the solar cell module, thereby protecting the solar cells 100 from the external environment. Such a backsheet may have a multi-layer structure such as a layer preventing moisture and oxygen penetration, a layer preventing chemical corrosion, and a layer having insulating properties.

The protective film is integrated with the solar cells 100 by a lamination process in a state in which they are disposed on the upper and lower sides of the solar cells 100, thereby preventing corrosion due to moisture penetration and protecting the solar cells 100 from impact . Such a protective film may be made of a material such as ethylene vinyl acetate (EVA).

The transparent member located on the protective film is made of a tempered glass or the like having a high transmittance and excellent breakage prevention function. At this time, the tempered glass may be a low iron tempered glass having a low iron content. This transparent member can be embossed on the inner side to enhance the light scattering effect.

The plurality of solar cells 100 provided in the solar cell module are arranged in the form of a plurality of strings. Here, the string refers to a plurality of solar cells electrically connected in a state of being arranged in a line.

Accordingly, the solar cell module shown in FIG. 1 includes four strings, for example, first to fourth strings S1, S2, S3, and S4.

The plurality of solar cells 100 arranged in the strings S1-S4 are electrically connected by the first inter connecter 200 and the second inter connecter 300, respectively.

In this embodiment, the first inter connecter 200 and the second inter connecter 300 are each formed of a flexible printed circuit (FPC).

The flexible printed circuit forming the first inter connecter 200 and the second inter connecter 300 is formed in a structure in which the conductive layer is located inside the protective film. At this time, since both ends of the conductive layer must contact the electrodes of the solar cell, the protective film is not located at both ends of the conductive layer.

Further, both ends of the conductive layer are exposed in opposite directions so as to face to different directions. And the conductive layer may be in the form of a single film.

A flexible printed circuit having such a structure can be easily carried out by those skilled in the art, and thus a detailed description thereof will be omitted.

More specifically, a structure in which a plurality of solar cells 100 are electrically connected to each other is described in detail. A structure in which a plurality of solar cells 100 are electrically connected to each other in a first direction Y- The plurality of solar cells 100 are electrically connected by a first interconnector 200 formed of a flexible printed circuit and electrically connected to each other in a second direction X-X 'intersecting the first direction Y-Y' Solar cells 100 of different strings arranged adjacent to each other are electrically connected by a second interconnector 300 formed of a flexible printed circuit.

In this case, the plurality of solar cells 100 may be formed in the same structure. Alternatively, some of the plurality of solar cells may be formed in different structures from the remaining solar cells.

As shown in FIG. 2, the solar cell 100 has a structure in which a plurality of solar cells 100 are formed in the same structure. The solar cell 100 includes a substrate 110, an emitter The first electrode 130 located on the emitter section 120 and the antireflection film 140 located on the emitter section 120 in the area where the first electrode 130 is not located, And a second electrode 160 positioned on the back surface of the rear electric field 150. The second electrode 160 is disposed on the back surface field (BSF)

The first electrode 130 includes a plurality of front electrodes 132 extending in one direction and a plurality of front electrodes 132 positioned on the emitter section 212 in a direction intersecting the front electrodes 132. In this embodiment, And the second electrode 160 includes a rear electrode 162 positioned on the entire rear surface of the rear electric part 150. The second electrode 160 may include a plurality of electrodes.

The substrate 110 is a semiconductor substrate of a first conductivity type, for example, silicon of p-type conductivity type. The silicon may be monocrystalline silicon, polycrystalline silicon or amorphous silicon. When the substrate 110 has a p-type conductivity type, it contains an impurity of a trivalent element such as boron (B), gallium (Ga), indium (In)

Although not shown, one side of the substrate 110 on which the emitter section 120 is located, for example, the light receiving surface, may be formed as a texturing surface including a plurality of concavities and convexities.

When the light receiving surface of the substrate 110 is formed as a textured surface, the light reflection on the light receiving surface is reduced, and the incidence and reflection operations are performed on the textured surface to increase the light absorption rate. Thus, the efficiency of the solar cell is improved.

The emitter portion 120 is a region doped with an impurity having a second conductivity type opposite to the conductivity type of the substrate 110, for example, an n-type conductivity type. The substrate 110 and the pn Junction.

When the emitter section 120 has an n-type conductivity type, the emitter section 120 may remove impurities of pentavalent elements such as phosphorus (P), arsenic (As), antimony (Sb) As shown in FIG.

Accordingly, when electrons in the semiconductor are energized by the light incident on the substrate 110, the electrons move toward the n-type semiconductor and the holes move toward the p-type semiconductor. Therefore, when the substrate 110 is p-type and the emitter section 120 is n-type, the separated holes move toward the substrate 110, and the separated electrons move toward the emitter section 120.

Conversely, the substrate 110 may be of the n-type conductivity type and may be made of a semiconductor material other than silicon. When the substrate 110 has an n-type conductivity type, the substrate 110 may contain impurities of pentavalent elements such as phosphorus (P), arsenic (As), antimony (Sb), and the like.

Since the emitter layer 120 forms a p-n junction with the substrate 110, when the substrate 110 has an n-type conductivity type, the emitter layer 120 has a p-type conductivity type. In this case, the separated electrons move toward the substrate 110 and the separated holes move toward the emitter part 120.

When the emitter section 120 has a p-type conductivity type, the emitter section 120 is formed by doping an impurity of a trivalent element such as boron (B), gallium (Ga), indium (In) .

An anti-reflection film 140 that is formed on the emitter layer 212 of the substrate 110 is a silicon nitride (SiNx), silicon oxide (SiO _2), silicon oxynitride film (SiOxNy), dioxide, titanium (TiO ₂₎ anti-reflective, such as And at least one film selected from the materials.

The antireflection film 140 reduces the reflectivity of the light incident on the solar cell 100 and increases the selectivity of the specific wavelength region to increase the efficiency of the solar cell 100. The antireflection film 140 may have a thickness of about 70 nm to 80 nm, and may be omitted if necessary.

The plurality of front electrodes 132 are formed on the emitter layer 120 and are electrically connected to the emitter layer 120 and spaced apart from the adjacent front electrodes 132 in one direction. Each of the front electrodes 132 collects charges, for example, electrons, which have migrated toward the emitter section 120, and transfers them to the front electrode current collector 134.

The front electrode 132 may be formed of at least one selected from the group consisting of Ni, Cu, Ag, Al, Sn, Zn, In, Ti, And at least one conductive material selected from the group consisting of combinations thereof.

A plurality of front electrode current collectors 134, also referred to as bus bars, are formed in a direction crossing the front electrodes 132. Therefore, the front electrode 132 and the front electrode current collector 134 are arranged to cross over the emitter section 120.

Although FIG. 2 shows one front electrode current collector 134, typically two or three front electrode current collectors 134 are provided in one solar cell.

The front electrode current collector 134 may be formed of a metal such as Ni, Cu, Ag, Al, Sn, Zn, In, Ti, (Au), and a combination thereof, and is connected to the emitter layer 120 and the front electrode 132. Therefore, the front electrode current collector 134 outputs electric charges, for example, electrons, transmitted from the front electrode 132 to an external device.

The front electrode current collector 134 may be formed of the same material as the front electrode 132, but may be formed of a different material from the front electrode 132.

The front electrode 132 and the front electrode current collector 134 are formed by applying a conductive metal material on the antireflection film 140 and then etching the antireflection film 140 using the etching component contained in the conductive metal material, And may be electrically connected to the emitter section 120.

The backside electric field 150 is a region where a conductive type impurity the same as the substrate 110 is doped at a higher concentration than the substrate 110, for example, a p + region.

This backside electrical section 150 acts as a potential barrier at the backside of the substrate 110. Therefore, since the recombination of electrons and holes at the rear side of the substrate 110 and the disappearance thereof are reduced, the efficiency of the solar cell is improved.

The second electrode 160 located on the rear surface of the rear electric field 150 collects electric charge, for example, holes moving toward the substrate 110. In this embodiment, And a rear electrode 162 which is made of a conductive material.

The back electrode 162 is made of at least one conductive material. The conductive material may be at least one selected from the group consisting of Ni, Cu, Ag, Al, Sn, Zn, In, Ti, Au, And combinations thereof, but may be made of other conductive materials.

Accordingly, the rear electrode 162 outputs the electric charge transmitted from the rear electric section 150 to the external device.

The plurality of solar cells provided in the solar cell module may all be the solar cell 100 according to the first embodiment described above.

As shown in FIG. 1, the solar cells 100 having such a configuration are electrically connected by the first interconnector 200 and the second interconnector 300, and the electrical connection between the adjacent solar cells 100 is The rear electrode 162 of another solar cell among the solar cells adjacent to the front electrode current collecting unit 134 of one of the adjacent solar cells is connected to the first interconnector 200 or the second interconnector 300, And are electrically connected to each other.

In particular, the electrical connection between adjacent solar cells 100 arranged in the same string is made by the first interconnector 200 located in the space between adjacent solar cells, and the adjacent solar cells 100 arranged in different strings 100 are made by a second interconnector 300 located in a space between adjacent solar cells.

In order to make the electrical connection between the adjacent solar cells 100 arranged in different strings, for example, the first string S1 and the second string S2 respectively, performed by the second interconnect 300, The solar cell located at the lowermost among the solar cells arranged in the one string S1 is arranged such that the front electrode current collector 134 is located in the second direction X-X '.

One end of the second inter connecter 300 is electrically connected to the front electrode collector 134 of the solar cell located at the bottom of the first string S1, And the other end can be electrically connected to the rear electrode 162 of the solar cell located at the lowermost side of the second string S1.

That is, since it is possible to place the second inter connecter 300 in the space between the solar cell located at the lowermost part of the first string S1 and the solar cell located at the lowermost part of the second string S2, The void space on the lower side of the battery module can be reduced.

Electrical connection between both ends of the second inter connecter and the electrode is performed by applying a conductive adhesive paste to the conductive layer exposed at both ends of the second inter connecter and then pressing the same at a predetermined temperature, for example, .

On the other hand, among the plurality of solar cells arranged in the first string S1, all of the solar cells other than the solar cells located below are positioned in the first direction Y-Y ' And adjacent solar cells are electrically connected by a first interconnector 200 located in the space between the cells.

Similarly, one solar cell among the solar cells located above the second string S2 and the third string S3 has the same structure as the solar cell located below the first string S1, And the front portion 134 is positioned in the second direction (X-X ').

Electrical connection of adjacent solar cells arranged in different strings is performed as described above, so that description of electrical connection of adjacent solar cells arranged in the third string S3 and the fourth string S4 is omitted.

The solar cell 100 and its electrical connection structure in the case where a plurality of solar cells 100 are all formed in the same structure has been described above.

Alternatively, some of the plurality of solar cells may be formed in a structure different from that of the remaining solar cells.

An example of such a case will be described. The solar cells on the lower side of the first string S1 and the third string S2 and the solar cell on the upper side of the second string S2 correspond to the solar cells 100A ), And the remaining solar cell may be composed of the solar cell 100 shown in Fig.

The solar cell 100A shown in FIG. 3 is different from the solar cell 100 shown in FIG. 2 in that a plurality of rear electrode current collectors 164A electrically connected to the rear electrode 162A are connected to the rear electric field 150A and the rear electrode current collector 164A is positioned in a direction parallel to the front electrode 132A.

In Fig. 3, elements corresponding to those in Fig. 2 are indicated by adding "A" after the reference numerals, so that the description of components corresponding to those in Fig. 2 will be omitted.

As described above, the solar cells on the lower side of the first string S1 and the third string S2 and the upper side solar cell of the second string S2 are made up of the solar cell 100A shown in FIG. 3, 2, the solar cells 100A are arranged such that the upper electrode current collector 134A is positioned in the second direction X-X ', and the solar cells 100 are arranged in the upper And the electrode current collector 134 are arranged in the first direction (Y-Y ').

Accordingly, adjacent solar cells arranged in different strings can be easily connected by the second interconnector 300 located in the space between the solar cells.

The upper solar cells of the second string S2 and the fourth strings S4 and the upper solar cells of the third string S3 are composed of the solar cells 100A, And the solar cell 100 shown in FIG.

In this case, the solar cell 100A is arranged such that the front electrode current collector 132A is positioned in the first direction Y-Y ' The upper solar cells of the cells 100 and the second string S2 are arranged such that the front electrode current collectors 132 are positioned in the second direction X-X ' And the electrode current collectors 132 are arranged in the first direction (Y-Y ').

Another example of the case where a part of the solar cells among the plurality of solar cells is formed in a structure different from that of the remaining solar cells will be described below. The solar cells below the first string S1 to the fourth string S4, The upper solar cell of the second string S2 and the third string S3 may be composed of the solar cell 100A shown in Fig. 3 and the remaining solar cells may be made of the solar cell 100B shown in Fig. 4 .

The solar cell 100B shown in FIG. 4 is different from the solar cell 100 shown in FIG. 2 in that a plurality of rear electrode current collectors 164B electrically connected to the rear electrode 162B are connected to the rear 150B and the rear electrode current collector 164B is positioned in a direction parallel to the front electrode current collector 134B.

In Fig. 4, components corresponding to Fig. 2 are indicated by adding "B" after the reference numerals, and description of components corresponding to those of Fig. 2 will be omitted.

The upper solar cells of the first string S1 to the fourth string S4 and the upper solar cells of the second string S2 and the third string S3 are connected to the solar cell 100A and the remaining solar cells are made of the solar cell shown in FIG. 4, the solar cells 100A and the second strings S2 of the first strings S1 and the third strings S3, The upper solar cell 100A is arranged such that the upper electrode collector 134A is located in the second direction X-X ', and the lower solar cell 100A is arranged such that the lower string of the second string S2 and the fourth string S4, The upper solar cell 100A of the upper solar cell 100A and the upper solar cell 100A is arranged such that the upper electrode current collector 134A is positioned in the first direction Y-Y ' Are arranged such that the upper electrode current collector portion 134B and the lower electrode current collector portion 164B are located in the first direction Y-Y '.

Although the first inter connecter 200 and the second inter connecter 300 formed of the flexible printed circuit have been described as examples in the above embodiments, as shown in FIG. 5, the first inter connecter 200 and the second inter connecter 300, The first inter connecter 200A and the second inter connecter 300A can be used.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

100, 100A, 100B: solar cell 200: first inter connecter
300: second inter connecter

Claims

1. A solar cell module comprising a plurality of strings formed by electrically connecting a plurality of solar cells arranged in a row,
A first inter connecter electrically connecting two solar cells arranged in the same string; And
At least one second inter connecter electrically connecting two solar cells arranged in different strings,
/ RTI >
Wherein the plurality of solar cells comprises a first electrode located on one side of the substrate and including a plurality of front electrode current collectors extending in parallel in one direction and a plurality of rear electrode housings located on the other side of the substrate The first electrode and the second electrode being formed to have the same structure,
One of the two solar cells electrically connected by the second inter connecter is arranged in the same state as the neighboring solar cell connected by the first inter connecter,
Wherein the other solar cell is arranged in a state of being rotated clockwise or counterclockwise at an angle of 90 DEG with respect to any one of the solar cells,
Wherein the first interconnector and the second interconnector are located in a space between solar cells electrically connected to each other.

The method of claim 1,
Wherein the first interconnector is located in the same first direction as the string and the second inter connector is located in the second direction intersecting the first direction.

3. The method of claim 2,
Wherein the second inter connecter is formed of a flexible printed circuit (FPC) or a strip-shaped ribbon.

3. The method of claim 2,
Wherein the first inter connecter is formed of a flexible printed circuit (FPC) or a strip-shaped ribbon.

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5. The method according to any one of claims 2 to 4,
Wherein the first electrode further comprises a plurality of front electrodes positioned in a direction crossing the front electrodes,
Wherein the second electrode further comprises a rear electrode electrically connected to the rear electrode current collector.

The method of claim 6,
Wherein one of the two solar cells electrically connected by the second inter connecter is arranged so that the front electrode current collector is located in the second direction, And the other one of the solar cells is arranged such that the front electrode current collector is located in the first direction.

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