KR20110012281A - Solar cell and solar cell module - Google Patents

Abstract

PURPOSE: A solar cell battery and a solar cell module are provided to improve the productivity by shortening the forming time of a connecting unit by arranging an electric storage unit for front electrode and an electric storage unit for rear electrode in tandem. CONSTITUTION: A substrate(110) of the first conductivity type is prepared. An emitter part(120) is formed in a second conductive type which is opposite of a first conductive type. A plurality of front electrodes(141) is electrically connected to the emitter part. A plurality of back electrodes(151) is electrically connected to the substrate. A plurality of electric storage units(161) for the front electrodes is electrically connected to the first electrode.

Description

Solar Cells and Solar Modules {SOLAR CELL AND SOLAR CELL MODULE}

The present invention relates to a solar cell and a solar cell module.

Recently, as the prediction of depletion of existing energy sources such as oil and coal is increasing, interest in alternative energy to replace them is increasing. Among them, solar cells are producing electric energy from solar energy, and are attracting attention because they are rich in energy resources and have no problems with environmental pollution.

A typical solar cell includes a substrate and an emitter layer made of semiconductors of different conductive types, such as p-type and n-type, and electrodes connected to the substrate and the emitter, respectively. At this time, p-n junction is formed in the interface of a board | substrate and an emitter part.

When light is incident on the solar cell, a plurality of electron-hole pairs are generated in the semiconductor, and the generated electron-hole pairs are separated into electrons and holes charged by the photovoltaic effect, respectively, and the electrons and holes are n-type. Move toward the semiconductor and the p-type semiconductor, for example toward the emitter portion and the substrate, collected by electrodes electrically connected to the substrate and the emitter portion, and connected to the wires to obtain power.

At this time, on the emitter portion and the substrate, at least one current collector such as a bus bar connected to each of the electrodes electrically connected to the emitter portion and the substrate is positioned so that the charge collected from the electrode passes through the adjacent current collector. Allow to move to externally connected load.

However, in this case, since the current collector is positioned not only on the substrate on which light is not incident, but also on the surface where the light is incident, that is, on the emitter portion formed on the incident surface, the incident area of light is reduced due to the current collector, thereby increasing the efficiency of the solar cell. Falls.

Therefore, to reduce the efficiency of solar cells due to current collectors, metal wrap through (MWT) solar cells or electrons and holes are placed at the rear of the substrate opposite the incident surface. Background Art A back contact solar cell or the like has been developed in which all electrodes to be transferred are positioned on the rear side of a substrate.

A plurality of solar cells of these structures are connected to form a solar cell module. At this time, by connecting the current collector formed in each solar cell in series or parallel form by using the connection portion to complete the electrical connection between the solar cells.

The technical problem to be achieved by the present invention is to reduce the manufacturing time of the solar cell module.

Another technical problem to be achieved by the present invention is to improve the production efficiency of the solar cell module.

According to one aspect of the present invention, a solar cell includes a substrate of a first conductivity type, an emitter part of a second conductivity type opposite to the first conductivity type, a plurality of first electrodes electrically connected to the emitter part, and an electrical signal to the substrate. A plurality of first collectors electrically connected to the first electrode, a plurality of first collectors electrically connected to the first electrodes, and a plurality of second collectors electrically connected to the second electrodes; Each is surrounded by each second current collector.

Each second current collector is spaced apart from each of the first contact parts and extends in parallel with each of the first contact parts, and extends in the opposite direction to the two extensions, and connects the two extensions to each other. It may include a connecting portion.

Preferably, the two gaps between the first current collector and two adjacent extensions are substantially the same.

A portion of the first current collector may overlap with a portion of the connection portion.

The solar cell according to an aspect of the present invention may further include an insulation portion between the first current collector and the connection portion overlapping the first current collector.

The solar cell according to an aspect of the present invention may further include at least one dummy electrode part electrically connected to at least one of the plurality of first electrodes.

The at least one dummy electrode part may not overlap the plurality of first current collectors.

The at least one dummy electrode part may include at least one dummy electrode extending in parallel with the first electrode, and at least one dummy connection part extending from the dummy electrode and connecting the dummy electrode and the first electrode. Can be.

The width of the dummy electrode may be smaller than the width of the dummy connection portion.

The second current collector may have a "-" shape.

The distance between the horizontal centerlines of two adjacent first current collectors may be about twice the distance between the horizontal centerlines of the first current collectors and the ends of the substrate adjacent to the first current collectors.

The plurality of first electrodes and the plurality of first current collectors extend in different directions, and the solar cell includes a plurality of parts of the substrate where the plurality of first electrodes and the plurality of first current collectors cross each other. The via hole may further include a plurality of first electrodes and the plurality of first current collectors. The via holes may be electrically connected to each other.

The plurality of first current collectors and the plurality of second current collectors may be positioned on a surface of the substrate to which light is not incident.

According to another aspect of the present invention, a solar cell module includes a substrate, an emitter portion formed on the substrate, a plurality of first electrodes electrically connected to the emitter portion, a second electrode electrically connected to the substrate, and the first electrode. A plurality of solar cells each having a plurality of first current collectors electrically connected to the plurality of second collectors, and a plurality of second current collectors electrically connected to the second electrodes, and a first solar cell of the plurality of solar cells. Two solar cells adjacent to each other in a row direction include a plurality of first connection portions connecting a first current collector portion and a second current collector portion of a second solar cell of the plurality of solar cells in a straight line, and are shifted in the longitudinal direction by a predetermined distance.

The plurality of first connection parts may be parallel to the plurality of first current collectors and the plurality of second current collectors.

Preferably, the plurality of first connection portions extend in parallel on the substrate.

The solar cell module according to the above features includes a second connection part connected to only the first current collector part or the second current collector part of each solar cell, and a third connection part respectively connected to the second connection parts positioned at two adjacent solar cells in the column direction. It may further include a connection.

Preferably, the second connection parts respectively positioned in two adjacent solar cells in the column direction are connected to different current collectors.

The first connection part and the second connection part may be formed of a conductive tape.

According to this feature, the connection operation for the connection of adjacent solar cells is easy, so that the manufacturing time of the solar cell module is reduced, the bowing of the solar cell is alleviated and the defective rate of the solar cell module is reduced.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement 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 the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like parts are designated by like reference numerals throughout the specification. 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. On the contrary, when a part is "just above" another part, there is no other part in the middle. In addition, when a part is formed "overall" on another part, it means that not only is formed on the entire surface (or front) of the other part but also is not formed on the edge part.

Next, a solar cell and a solar cell module according to an embodiment of the present invention will be described with reference to the accompanying drawings.

First, a solar cell according to an exemplary embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4 and FIGS. 5A and 5B.

1 is a partial perspective view of a solar cell according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view of the solar cell illustrated in FIG. 1 taken along line II-II. 3 is a schematic layout view of a solar cell according to an exemplary embodiment of the present invention, and FIG. 4 is a cross-sectional view of the solar cell shown in FIG. 3 taken along line IV-IV. 5A and 5B are diagrams illustrating a front electrode disposed on a front surface of the solar cell shown in FIG. 3 and a front electrode collector disposed on a rear surface and a collector for a rear electrode disposed on a rear surface thereof, respectively.

1 and 2, a solar cell 1 according to an embodiment of the present invention includes a substrate 110 and a substrate 110 having a plurality of via holes 181. The anti-reflection film 130 and the anti-reflection film 130 positioned on the emitter part 120 and the emitter part 120 on the surface of the substrate 110 to which light is incident (hereinafter referred to as “front surface”) are A plurality of front electrodes 141 positioned on the emitter unit 120 in front of the substrate 110 that is not positioned, and the surface of the substrate 110 facing the front without incident light (hereinafter, referred to as' rear ( rear electrode 151 located at the rear surface of the substrate 110 and located at the emitter unit 120 at the rear of the substrate 110 positioned around the via hole 181 and the via hole 181. A plurality of front electrode current collector 161, electrically connected to the 141, a plurality of rear electrodes positioned on the rear of the substrate 110 and electrically connected to the rear electrode 151 The plurality of insulating parts 190 located at the overlapping portion of the current collector 162, the plurality of front electrode current collectors 161 and the plurality of rear electrode current collectors 162, and the rear electrode 151 and the substrate ( And a back surface field (BSF) portion 171 positioned between 110.

The substrate 110 is a semiconductor substrate made of silicon of a first conductivity type, for example a p-type conductivity type. In this case, the silicon may be monocrystalline silicon, a polycrystalline silicon substrate, or amorphous silicon. When the substrate 110 has a p-type conductivity type, it contains impurities of trivalent elements such as boron (B), gallium, indium, and the like. Alternatively, the substrate 110 may be of an n-type conductivity type or 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), and antimony (Sb).

The substrate 110 has a plurality of via holes 181 penetrating through the substrate 110 and has a texturing surface that is textured to have a textured surface.

The emitter portion 120 formed on the substrate 110 is an impurity portion having a second conductivity type, for example, an n-type conductivity type, which is opposite to the conductivity type of the substrate 110. pn junction.

Due to this built-in potential difference due to the pn junction, electron-hole pairs, which are charges generated by light incident on the substrate 110, are separated into electrons and holes, and the electrons move toward the n-type and the holes Moves toward p-type. Therefore, when the substrate 110 is p-type and the emitter portion 120 is n-type, the separated holes move toward the substrate 110 and the separated electrons move toward the emitter portion 120, whereby holes in the substrate 110 are formed. Is the majority carrier, and the electron in the emitter unit 120 becomes the majority carrier.

Since the emitter portion 120 forms a pn junction with the substrate 110, unlike the present embodiment, when the substrate 110 has an n-type conductivity type, the emitter portion 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 unit 120 has an n-type conductivity type, the emitter unit 120 may be doped with impurities of a pentavalent element such as phosphorus (P), arsenic (As), antimony (Sb), etc. on the substrate 110. On the contrary, when the emitter portion 120 has a p-type conductivity type, impurities of trivalent elements such as boron (B), gallium (Ga), and indium (In) may be doped into the substrate 110. Can be formed.

An anti-reflection film 130 made of a silicon nitride film (SiNx), a silicon oxide film (SiOx), or the like is formed on the emitter portion 120 on the entire surface of the substrate 110. The anti-reflection film 130 reduces the reflectivity of light incident on the solar cell 1 and increases the selectivity of a specific wavelength region, thereby increasing the efficiency of the solar cell 1. The anti-reflection film 130 may have a multilayer structure such as a single layer structure or a double layer, and may be omitted as necessary.

An exposed portion 182 is formed in the anti-reflection film 130 and the emitter portion 120 thereunder to expose a portion of the edge of the front surface of the substrate 110. Therefore, the emitter unit 120 formed on the front surface of the substrate 110 and the emitter unit 120 formed on the rear surface of the substrate 110 are electrically separated by the exposed portion 182.

The plurality of front electrodes 141 are positioned on the emitter part 120 formed on the front surface of the substrate 110 and electrically connected to the emitter part 120. The plurality of front electrodes 141 are spaced apart from each other, extend in parallel to each other in a predetermined direction, and cover the via holes 181 positioned below.

Each front electrode 141 collects electric charges, for example, electrons, which are moved toward the emitter unit 120, and transfers the electrons to the front electrode current collector 161 that is electrically connected through the via hole 181.

The front electrodes 141 are made of at least one conductive material, and examples of the conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), and zinc ( Zn), at least one selected from the group consisting of indium (In), titanium (Ti), gold (Au), and combinations thereof, but may be made of other conductive metal materials.

A plurality of front electrode current collectors 161 made of at least one conductive material are disposed on the rear surface of the substrate 110. The plurality of front electrode current collectors 161 are also called bus bars and extend in a direction crossing the plurality of front electrodes 141 positioned on the front surface of the substrate 110.

Accordingly, the plurality of front electrodes 141 and the plurality of via holes 181 electrically connecting the plurality of front electrode current collectors 161 intersecting the plurality of front electrodes 141, respectively, are provided in the plurality of front electrodes 141. And a plurality of front electrode current collectors 161 are formed on the substrate 110 at the intersection portion.

The plurality of front electrode current collectors 161 output the charges transferred from the plurality of front electrodes 141 electrically connected to the external device.

Examples of conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au) and It may be at least one selected from the group consisting of a combination thereof, but may be made of another conductive metal material other than the above.

The rear electrode 151 is positioned to be spaced apart from the front electrode current collector 161 adjacent to the rear surface of the substrate 110 and electrically connected to the substrate 110. The back electrode 151 collects charges, for example holes, moving toward the substrate 110.

The emitter unit 120 formed between the rear electrode 151 and the plurality of front electrode current collectors 161 includes a plurality of exposed portions 183 exposing a portion of the rear surface of the substrate 110.

The exposed portion 183 disconnects electrical connections between the front electrode current collector 161 for collecting electrons or holes and the rear electrode 151 for collecting holes or electrons, thereby facilitating movement of electrons and holes.

The back electrode 151 is made of at least one conductive material. Conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au) and their It may be at least one selected from the group consisting of a combination, but may be made of other conductive materials.

A plurality of rear electrode current collectors 162 made of a conductive material and electrically connected to the rear electrode 151 are disposed on the rear surface of the substrate 110. In this case, a part of the emitter unit 120 is present on the current collector 162 for the rear electrode, but is not limited thereto.

Each of the rear electrode current collectors 162 is a rod-shaped electrode which extends along the adjacent front electrode current collector 161 with the front electrode current collector 161 interposed therebetween, as shown in FIGS. 3 and 5B. A connecting portion 1623 connecting the two extensions 1621 and 1622 to each other across the current collector portion 161 for the true electrode positioned between the two extensions 1621 and 1622 and the two extensions 1621 and 1622. Has) Therefore, in the present embodiment, each of the rear electrode current collectors 162 has a "C" shape, and the front electrode current collector 161 is a rear electrode at the center of each rear electrode current collector 162. Parallel to the current collector 162 extends while overlapping a portion of the connection portion 1623 of the current collector 162 for the rear electrode. For this reason, the front electrode current collector 161 is surrounded by the rear electrode current collector 162 except for a part thereof.

Examples of conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au) and It may be at least one selected from the group consisting of a combination thereof, but may be made of another conductive metal material other than the above.

The plurality of rear electrode current collectors 162 output electric charges, for example, holes, transmitted from the rear electrode 151 electrically connected to the external device.

In the present embodiment, the number of the front electrode current collector 161 and the rear electrode current collector 162 may be two or more, and the number thereof may be changed as necessary.

Also in alternative embodiments, the back electrode 151 and the back electrode current collector 162 may partially overlap.

As shown in FIGS. 3 and 4, the plurality of insulating portions 190 exist only between the current collector 162 for the rear electrode and the current collector 161 for the front electrode thereunder, and therebetween. Insulate As a result, the plurality of insulation parts 190 are positioned between each front electrode current collector 161 and the connection portion 1623 of each of the front electrode current collectors 162 overlapping the front electrode current collector 161. . Referring to FIGS. 3 and 4, the plurality of insulation parts 190 may be positioned inside the exposed part 183, but are not limited thereto and may be positioned beyond the exposed part 183.

The rear electric field unit 171 is positioned between the rear electrode 151 and the substrate 110. The back surface field part 171 is a region in which impurities of the same conductivity type as the substrate 110 are doped at a higher concentration than the substrate 110, for example, a P + region.

Due to the impurity concentration difference between the substrate 110 and the backside electric field 170, a potential barrier is formed, which prevents electrons from moving toward the backside of the substrate 110, and electrons and holes recombine and disappear near the surface of the substrate 110. Reduce the likelihood

Next, the plurality of front electrode current collectors 161 and the plurality of rear electrode current collectors 162 positioned on the rear surface of the substrate 110 will be described in more detail.

3 and 5B, in the present embodiment, the number of the front electrode current collector 161 and the rear electrode current collector 162 is three, but may be two or four or more.

That is, one front electrode current collector 161 is positioned so that the longitudinal center line L1 of the substrate 110 and its horizontal axis center line coincide with each other, and the current collector for front electrode disposed on the center line L1 of the substrate 110. The front electrode current collector 161 is positioned below and above the center 161, respectively.

At this time, the distance d2 between the horizontal axis center line of the front electrode current collector 161 located in the center and the front electrode current collector 161 located above and below the center of the front electrode current collector 161 located at the center thereof are mutually different. same.

In addition, the distance d1 between the upper end of the substrate 110 and the horizontal axis center line of the front electrode current collector 161 adjacent to the end and the lower end of the substrate 110 and the current collector for the front electrode adjacent to the end ( The distance d1 between the horizontal axis center lines of 161 is also the same.

These intervals d1 and d2 are determined based on the moving distance of the charge moving through the front electrode 141. In this embodiment, the size of the interval d2 is about twice as large as the size of the interval d1. Therefore, when a charge existing between two adjacent front electrode current collectors 161 moves through the adjacent front electrode 141 and moves to the front electrode current collector 161 through the corresponding via hole 181, the moving distance is far. This prevents phenomena from disappearing in the immediate middle. However, the size relationship between these intervals d1 and d2 is not limited to this and can be changed.

The distance L2 between the horizontal axis center line of each front electrode current collector 161 and the extension portions 1621 and 1622 of the corresponding rear electrode current collector 162 positioned respectively below and above the front electrode current collector 161 is Same as each other. Accordingly, the distance L21 between the front electrode current collector 161 and the rear electrode current collector 162 located above and below the front electrode current collector 161 is also the same.

The widths w1 of the front electrode current collector 161 are all the same, and the widths w2 of the rear electrode current collector 161 are also the same. In the present embodiment, the width w1 of the front electrode current collector 161 is wider than the width w2 of the rear electrode current collector 162, but is not limited thereto.

The solar cell 1 according to the present exemplary embodiment having the structure as described above is a solar cell in which a front electrode current collector 161 connected to the front electrode 141 is positioned on the rear surface of the substrate 110 where no light is incident. The operation is as follows.

When light is irradiated onto the solar cell 1 and incident on the substrate 110 of the semiconductor through the emitter unit 120, electron-hole pairs are generated in the substrate 110 of the semiconductor by light energy. At this time, since the surface of the substrate 110 is a texturing surface, the light reflectivity of the entire surface of the substrate 110 is reduced, and incident and reflection operations are performed on the texturing surface to trap light in the solar cell, thereby increasing light absorption. The efficiency of the solar cell is improved. In addition, the reflection loss of light incident on the substrate 110 by the anti-reflection film 130 is reduced, so that the amount of light incident on the substrate 110 is further increased.

These electron-hole pairs are separated from each other by a pn junction of the substrate 110 and the emitter portion 120 so that the electrons move toward the emitter portion 120 having an n-type conductivity type, and the holes form a p-type conductivity type. The substrate 110 moves toward the substrate 110. As such, the electrons moved toward the emitter unit 120 are collected by the front electrode 141 and moved to the front electrode current collector 161 electrically connected through the via hole 181, and moved toward the substrate 110. The holes are collected by the rear electrode 151 through the rear electric field unit 171 and move to the current collector 162 for the rear electrode. When the front electrode current collector 161 and the rear electrode current collector 162 are connected with a conductive wire, a current flows, which is used as power from the outside.

The solar cell 1 may be used alone, but for more efficient use, a plurality of solar cells 1 having the same structure are connected to form a solar cell module.

Next, a solar cell module using a solar cell according to an embodiment of the present invention will be described with reference to FIGS. 6 and 7.

6 is a schematic perspective view of a solar cell module according to an embodiment of the present invention, Figure 7 is a view showing a schematic connection state of a solar cell array using a solar cell according to an embodiment of the present invention.

Referring to FIG. 6, the solar cell module 20 according to the present embodiment is positioned on the back sheet 210, the lower filler 220 and the lower filler 220 positioned on the rear sheet 210. A solar cell array 10, an upper filler 230 positioned on the solar cell array 10, a transparent member 240 positioned on the upper filler 230, and a frame 250 for storing the components thereof. Equipped.

The rear sheet 210 protects the embedded solar cell 1 from the external environment by preventing moisture from penetrating from the rear of the solar cell module 20.

The back sheet 210 may have a multilayer structure such as a layer for preventing moisture and oxygen penetration, a layer for preventing chemical corrosion, and a layer having insulation properties.

The lower and upper fillers 220 and 230 are encapsulate materials to prevent corrosion of the metal due to moisture penetration and to protect the solar cell module 20 from impact. The fillers 220 and 230 may be made of a material such as ethylene vinyl acetate (EVA).

The transparent member 230 positioned on the upper filler 230 has a high transmittance and is made of tempered glass to prevent breakage. In this case, the tempered glass may be a low iron tempered glass having a low iron content. The transparent member 230 may be embossed on the inner surface in order to enhance the light scattering effect.

As shown in FIG. 7, the solar cell array 10 includes a plurality of solar cells 1 arranged in a matrix structure, and each solar cell 1 is connected in series by a plurality of connecting portions 21-24. Is connected. In FIG. 7, the solar cell array 10 has a 4 × 4 matrix structure. However, the solar cell array 10 is not limited thereto, and the number of the solar cells 1 arranged in the row and column directions may be adjusted as necessary.

Except for the solar cells 1 located in the first column of the first row and the last row, the front electrode current collector 161 and the rear electrode current collector 162 respectively formed in two adjacent solar cells 1 are straight lines. Is connected.

Next, with reference to FIG. 7, the connection relationship of the solar cell 1 using the some connection part 21-24 is demonstrated in detail.

First, as shown in FIG. 7, when the arrangement of the plurality of solar cells 1 arranged in the solar cell array 10 is described, the adjacent solar cells 1 in the row direction are moved upward or downward by a predetermined distance. The front electrode current collectors 161 and the rear electrode current collectors 162 of the two solar cells 1 adjacent to each other in the row direction are positioned on a straight horizontal line. In this embodiment, as shown in Fig. 7, two solar cells 1 adjacent in the row direction are shifted by a distance of "L3" (= L21 + W2).

At this time, the front electrode current collector 161 of each solar cell 1 alternates with the extension 1621 or extension 1622 of the rear electrode current collector 162 of the solar cell 1 adjacent in the row direction. Are located on the same extension line.

As such, as shown in FIG. 7, the plurality of solar cells 1 arranged in a matrix structure are connected in series by a plurality of connecting portions 21-24.

 The plurality of first connectors 21 are positioned on the two solar cells 1 adjacent to each other in the row direction, but are disposed on the front electrode current collector 161 and the rear electrode current collector 162 horizontally arranged in a single line. The front electrode current collector 161 and the rear electrode current collector 162 adjacent in the row direction are connected horizontally in a straight line without bending. These plurality of first connecting portions 21 extend in parallel in the solar cell 1 (or the substrate 110).

At this time, both ends of the first connection portion 21 do not leave the solar cell 1 in which the front electrode current collector 161 and the rear electrode current collector 162 are connected to each other.

The width of each connecting portion 21 is greater than or equal to the width of each of the front electrode and the rear electrode current collectors 161 and 162, so that the contact force and the charge transfer capability between the front electrode and the rear electrode current collectors 161 and 162 are the same. To improve. However, the present invention is not limited thereto, and the width of the first connection part 21 may be smaller than the widths of the front and rear electrode current collectors 161 and 162.

When the front electrode current collector 161 and the rear electrode current collector 162 are connected to each other by the first connector 21, the connection form (order) of the plurality of solar cells 1 present in the same row is the same. In addition, the connection form (order) of the some solar cell 1 which exists in two adjacent rows differs from each other.

That is, in two adjacent solar cells 1 in the odd-numbered rows, the front electrode current collector 161 of the solar cell 1 located at the front and the rear electrode current collector 162 of the solar cell 1 located at the rear thereof. Is connected by the first connecting portion 21, while in the adjacent two solar cells 1 in the even-numbered row, the current collector 162 for the rear electrode of the solar cell 1 located in front and the solar cell located in the rear ( The current collector 161 for the front electrode of 1) is connected by the first connector 21.

In the same row, the front electrode current collector 161 is alternately connected to one of the first and second extensions 1621 and 1622 of the current collector 162 for the rear electrode.

The solar cells 1 positioned in the same row are connected in series by the first connecting portion 21.

The plurality of second connectors 22 are positioned on the front electrode current collector 161 or the rear electrode current collector 162 of the solar cell 1 positioned in the first and last columns.

One end of each second connecting portion 22 is located outside the left end face or the right end face of the solar cell 1.

As such, since the second connector 22 is positioned only on one of the current collectors 161 and 162 of the front electrode current collector 161 and the rear electrode current collector 162, the length of the second connector 22 is It is shorter than the length of the first connection portion 21 positioned on one front electrode current collector 161 and one back electrode current collector 162, and is approximately half the length of the first connection portion 21.

In addition, similarly to the first connecting portion 21, the width of each second connecting portion 21 in order to improve the contact force and the charge transfer ability with the front electrode current collector 161 or the rear electrode current collector 162. Is greater than or equal to the width of each front electrode current collector 161 or each rear electrode current collector 162, but is not limited thereto.

The plurality of third connectors 23 are connected to the plurality of second connectors 22 of the solar cells 1 located in the first column of the first and last rows and mainly extend in the longitudinal direction. These third connectors 23 are connected to external devices through separate wires (not shown). Unlike in FIG. 11, at least one end of the third connecting portion 23 may be elongated to facilitate connection with an external device.

The plurality of fourth connectors 24 are used to connect the solar cells 1 positioned in different rows in series. The fourth and second connectors 24 are positioned in two adjacent solar cells 1 in the column direction in the first and last columns. It is connected to the 2 connection part 22, and mainly extends in a vertical direction.

Therefore, the fourth connector 24 is disposed in the outermost part of the solar cell 1, ie, the solar cell array 10, arranged in the first and last columns except for the solar cell 1 connected to the third connector 23. Of the solar cells 1, it is connected with the second connecting portion 22 of two solar cells 1 adjacent in the longitudinal direction. In this case, the second connectors 22 of the two solar cells 1 adjacent in the vertical direction are positioned on different current collectors 161 and 162.

These first to fourth connections 21-24 are made of a conductive tape, which is a thin metal plate strip having a conductive shape and having a string shape, commonly referred to as a ribbon. Examples of conductive materials include nickel (Ni), copper (Cu), silver (Ag), aluminum (Al), tin (Sn), zinc (Zn), indium (In), titanium (Ti), gold (Au) and It may be at least one selected from the group consisting of a combination thereof, but may be made of other conductive materials.

As a result, the plurality of solar cells 1 disposed in the solar cell module 20 by the first to fourth connectors 21-24 are connected in series to form the solar cell array 10.

In the case of FIG. 7, the solar cells 1 located in the first column of the first row to the solar cells 1 located in the first column of the last row are connected in series in a zigzag fashion, but alternatively, the third and fourth connections 23 , 24) can be connected in series in a zigzag form from the solar cells 1 located in the last column of the first row to the solar cells 1 located in the last column of the last row.

In addition, as described above, the third connector 23 is connected to an external device (not shown) through wires (not shown) formed separately from the back sheet 210 or the like.

As described above, since the connection form between the front electrode current collector 161 and the rear electrode current collector 162 is changed for each row and column by the plurality of first connection parts 21, which are conductive tapes, the tension due to the conductive tape ( The effect of tension is distributed in various directions in the solar cell array 10. Therefore, the warpage phenomenon of the solar cell 1 is reduced and the breakage rate of the solar cell 1 is reduced.

The solar cells 1 adjacent to each other in the row direction are disposed to be shifted upwards or downwards by a predetermined distance, so that the front electrode current collector 161 and the rear electrode current collector 162 of the two solar cells 1 adjacent to each other in the row direction. ) Is located in a straight line on the same substrate surface, the formation time of the first connecting portion 21 is greatly reduced. In addition, since all of the first to fourth connectors 21-24 are attached to the same surface, which is substantially the rear surface of the solar cell 1, the formation time of the first to fourth connectors 21-24 is also reduced. As a result, the front electrode current collector 161 and the rear electrode current collector 162 may be easily connected to reduce the manufacturing time and the defective rate of the solar cell array 10.

Next, a solar cell according to another exemplary embodiment of the present invention will be described with reference to FIGS. 8, 9, 10A, and 10B.

In the solar cell 1a according to the present embodiment, the same components as those of the solar cell 1 described with reference to FIGS. 1 to 5B are denoted by the same reference numerals, and detailed description thereof is also omitted.

8 is a schematic layout view of a solar cell according to another embodiment of the present invention, and FIG. 9 is a cross-sectional view of the solar cell shown in FIG. 8 taken along the line IX-IX. 10A and 10B are diagrams showing a front electrode disposed on the front surface of the solar cell shown in FIG. 8 and a front electrode collector disposed on the rear surface and a collector for the rear electrode disposed on the rear surface, respectively.

The solar cell 1a according to the present embodiment shown in FIG. 8 has a structure similar to that of the solar cell 1 shown in FIGS.

That is, the solar cell 1a illustrated in FIG. 8 includes a substrate 110 including a plurality of via holes 181, an emitter unit 120 disposed on the substrate 110, and a reflection located on the emitter unit 120. The prevention layer 130, the plurality of front electrodes 141 electrically connected to the emitter unit 120 on the front surface of the substrate 110, the rear electrodes 151 electrically connected to the rear surface of the substrate 110, and via holes 181. A plurality of front electrode current collectors 161 electrically connected to the front electrode 141, a plurality of rear electrode current collectors 162 electrically connected to the rear electrodes 151, and a rear electrode And a rear electric field part 171 positioned between the 151 and the substrate 110.

However, unlike the solar cell 1 shown in FIGS. 1 to 3, in the solar cell 1a according to the present embodiment, each current collector 161 for each of the front electrodes is connected to each current collector 162 for each of the rear electrodes. Do not overlap That is, as shown in FIGS. 8 and 10B, the front electrode current collector 161 is mostly surrounded by the “c” shaped rear electrode current collector 162 except for one surface.

For this reason, the solar cell 1a of this embodiment is provided with the dummy electrode part 143 located in the front surface of the board | substrate 110. FIG. Therefore, as shown in FIG. 8, since the dummy electrode part 143 does not overlap the front electrode current collector 161, the dummy electrode part 143 is positioned on the portion of the substrate 110 where the front electrode current collector 161 is not formed.

8 and 10A, the dummy electrode portion 143 is formed on the left side of the substrate 110 (solar cell 1a), but is not limited thereto, and the right side of the substrate 110 (solar cell 1a). It may also be formed in each of the portions or the left portion and the right portion.

The dummy electrode part 143 extends in a direction crossing the plurality of dummy electrodes 143a and the plurality of dummy electrodes 143a extending in the same direction as the front electrode 141 and connect the adjacent front electrodes 141. A dummy connection portion 143b.

The plurality of dummy electrodes 143a do not overlap the current collector 161 for the front electrode.

The plurality of dummy connectors 143b extend from the dummy electrodes 143a and extend in a direction crossing the dummy electrodes 143a. By the dummy connection part 143b, the plurality of dummy electrodes 143a are all physically and electrically connected, and the plurality of dummy electrodes 143a are physically and electrically connected to the adjacent front electrode 141.

In the present embodiment, the width of each dummy electrode 143a is smaller than the width of each dummy connection part 143b, but may be the same or smaller.

Each dummy electrode 143a collects charges transferred to the emitter part 120 and transfers them to the connection part 143b, similarly to the front electrode 141, and the connection part 143b transfers the collected charges to the adjacent front electrode. Transfer to 141 to be delivered to the current collector for the front electrode 161 through the adjacent via hole 181.

As such, since the plurality of dummy electrodes 143a do not cross the front electrode current collector 161, the via holes 181 are not formed in the substrate 110 corresponding to the plurality of dummy electrodes 143a. Through the dummy connection parts 143b, the plurality of dummy electrodes 143a are electrically connected to the current collector 161 for the front electrode.

Since the number of dummy electrodes 143a and dummy connectors 143b shown in FIGS. 8 and 10A is for illustration only, the present invention is not limited thereto.

Thus, in an alternative embodiment, the number of dummy electrode portions 143 may be one. Also, in the present embodiment, the number of dummy connectors 143b is the same as the number of collectors 161 for the front electrode, but in an alternative embodiment, the number of dummy connectors 143b is the collector 161 for the front electrodes. May be greater than the number of.

In the present embodiment, the dummy connection part 143b is formed based on the formation position of the adjacent via hole 181, but is not limited thereto.

As described above, when the solar cell 1a is formed, the front electrode current collector 161 and the rear electrode current collector 162 do not overlap each other, and thus a separate insulating part is not required, and thus a manufacturing process of the solar cell 1a is performed. This becomes easy.

After arranging such solar cells 1a in a matrix structure, a solar cell array 10a formed by using the first to fourth connectors 21-24 is shown in FIG. 11.

11 is a view showing a schematic connection state of the solar cell array using a solar cell according to another embodiment of the present invention.

As shown in FIG. 11, except for the structure of the front electrode current collector 161 of each solar cell 1a, a plurality of solar cells 1a are connected in series as in the solar cell array 10 shown in FIG. Connected to form the solar cell array 10a.

That is, as in FIG. 7, two solar cells 1a adjacent to each other in the row direction are positioned to be shifted upward or downward by a predetermined distance, so that the front electrode current collector 161 and the rear surface of each of the two adjacent solar cells 1a are respectively located. The electrode current collector 162 is positioned on a straight horizontal line.

Then, the front electrode current collector 161 and the rear electrode current collector 162 of the solar cell 1a adjacent in the row direction and the column direction are serially connected using the first to fourth connection parts 21-24. By connecting to the solar cell array 10a.

Therefore, in the same manner as described above on the basis of the solar cell array 10, when forming the solar cell array 10a, the front electrode house 161 and the front electrode by the first to fourth connection portions 21-24, Since the connection state between the current collectors 162 for the rear electrodes is changed for each row and column, the warpage of the solar cell 1a is reduced, thereby reducing the breakage rate of the solar cell 1a. In addition, since the front electrode current collector 161 and the rear electrode current collector 162 are disposed in a straight line on the same substrate surface, the formation time of the first to fourth connectors 21-24 is greatly reduced, and the front electrode collector It is easy to connect the whole 161 and the current collector 162 for the rear electrode, thereby reducing the manufacturing time and defective rate of the solar cell array 10.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a partial perspective view of a solar cell according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the solar cell illustrated in FIG. 1 taken along the line II-II.

3 is a schematic layout view of a solar cell according to an embodiment of the present invention.

4 is a cross-sectional view of the solar cell illustrated in FIG. 3 taken along the line IV-IV.

5A and 5B are diagrams illustrating a front electrode collector and a rear electrode collector disposed on the front electrode and the rear of the solar cell illustrated in FIG. 3, respectively.

6 is a schematic perspective view of a solar cell module according to an embodiment of the present invention.

7 is a view showing a schematic connection state of the solar cell array using a solar cell according to an embodiment of the present invention.

8 is a schematic layout view of a solar cell according to another embodiment of the present invention.

FIG. 9 is a cross-sectional view of the solar cell illustrated in FIG. 8 taken along the line IX-IX. FIG.

10A and 10B are diagrams respectively illustrating a front electrode and a rear electrode current collector disposed on the front electrode and the rear of the solar cell shown in FIG. 8, respectively.

11 is a view showing a schematic connection state of the solar cell array using a solar cell according to another embodiment of the present invention.

Brief description of the main parts of the drawing

1, 1a: solar cell 10, 10a: solar cell array

20: solar cell module 21-24: connection portion

110: substrate 120 emitter part

141: front electrode 143: dummy electrode portion

143a: dummy electrode 143b: dummy connection

151: rear electrode 161: front electrode collector

162: rear electrode collector 171: rear electric field

190: insulation portion 210: rear sheet

220, 230: Filler 240: Transparent member

250: frame 310: insulation

Claims (19)

A substrate of a first conductivity type, An emitter portion of a second conductivity type opposite to the first conductivity type, A plurality of first electrodes electrically connected to the emitter unit, A second electrode electrically connected to the substrate, A plurality of first current collectors electrically connected to the first electrodes, and A plurality of second current collectors electrically connected to the second electrodes And, Each of the plurality of first current collectors is surrounded by each second current collector. Solar cells. In claim 1, Each second current collector is spaced apart from each of the first contact parts and extends in parallel with each of the first contact parts, and extends in the opposite direction to the two extensions, and connects the two extensions to each other. Connection Solar cell comprising a. In claim 2, Wherein the two spacings between the first current collector and two adjacent extensions are substantially equal. In claim 2, A portion of the first current collector portion overlaps a portion of the connection portion. In claim 4, The solar cell further comprises an insulating portion between the first current collector and the connection portion overlapping the first current collector. The method of claim 1 or 2, And at least one dummy electrode part electrically connected to at least one of the plurality of first electrodes. In claim 6, The at least one dummy electrode part does not overlap the plurality of first current collectors. In claim 6, The at least one dummy electrode portion, At least one dummy electrode extending in parallel with the first electrode, and At least one dummy connection part extending from the dummy electrode and connecting the dummy electrode and the first electrode; Solar cell comprising a. In claim 8, The width of the dummy electrode is smaller than the width of the dummy connection portion. In claim 2, The second current collector is a "C" shaped solar cell. In claim 1, Wherein the spacing between two adjacent first current collectors' horizontal centerlines is about twice the distance between the transverse centerlines of the first current collectors and the ends of the substrate adjacent the first current collectors. In claim 1, The plurality of first electrodes and the plurality of first current collectors extend in different directions, The solar cell further includes a plurality of via holes in a portion of the substrate where the plurality of first electrodes and the plurality of first current collectors cross each other. The plurality of first electrodes and the plurality of first current collectors are electrically connected through the via holes. Solar cells. In claim 1, And the plurality of first collectors and the plurality of second collectors are disposed on a surface of the substrate to which light is not incident. A substrate, an emitter portion formed on the substrate, a plurality of first electrodes electrically connected to the emitter portion, a second electrode electrically connected to the substrate, and a plurality of first current collectors electrically connected to the first electrode And a plurality of solar cells each having a plurality of second current collectors electrically connected to the second electrodes, and A plurality of first connection portion connecting the first current collector of the first solar cell of the plurality of solar cells and the second current collector of the second solar cell of the plurality of solar cells in a straight line Including, Two solar cells adjacent in a row direction are shifted longitudinally by a fixed distance Solar modules. The method of claim 14, And the plurality of first connection portions are parallel to the plurality of first current collectors and the plurality of second current collectors. The method of claim 14, And the plurality of first connectors extend in parallel on the substrate. The method of claim 14, The solar cell module further includes a second connection part connected to only the first current collector part or the second current collector part of each solar cell, and a third connection part connecting the second connection parts respectively located at two adjacent solar cells in the column direction. . The method of claim 17, And the second connection parts respectively positioned on two adjacent solar cells in the column direction are connected to different current collectors. The method of claim 17, The first connector and the second connector is a solar cell module formed of a conductive tape.

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