KR101231314B1

KR101231314B1 - Solar cell module

Info

Publication number: KR101231314B1
Application number: KR1020110049366A
Authority: KR
Inventors: 이준성; 송석현; 양수미; 조은철; 이원재; 정상윤; 안수범; 이경원; 주상민
Original assignee: 현대중공업 주식회사
Priority date: 2011-05-25
Filing date: 2011-05-25
Publication date: 2013-02-07
Also published as: KR20120131301A

Abstract

The present invention omits the busbar doping layer and arranges the busbar electrodes in such a manner as to cross the fingerline electrodes, and laminates the ribbons in a surface contact form on the busbar electrodes to improve electrical characteristics between the ribbon and the busbar electrodes. Regarding a solar cell module that can be improved, the solar cell module according to the present invention includes a first solar cell, a second solar cell, and a ribbon connecting the first solar cell and the second solar cell. The first solar cell or the second solar cell includes a substrate, a plurality of n-type fingerline doping layers n + and a plurality of p-type fingerline doping layers p + disposed alternately inside the back surface of the substrate, and the plurality of solar cells. A dielectric layer laminated on a substrate including an n-type fingerline doped layer (n +) and a plurality of p-type fingerline doped layers (p +), and an n-type fingerline formed on the n-type fingerline doped layer (n +) The length corresponding to the doping layer (n +) An n-type fingerline electrode, a p-type fingerline electrode formed on the p-type fingerline doping layer p +, and having a length corresponding to a p-type fingerline doping layer p +, and the p-type fingerline electrode An insulating mask provided on the first end of the p-type fingerline electrode and an n-type busbar electrode provided on the dielectric layer and electrically connected to the plurality of n-type fingerline electrodes; And a p-type busbar electrode electrically connected to the plurality of p-type fingerline electrodes.

Description

Solar cell module

The present invention relates to a solar cell module, and more particularly, omits the busbar doping layer and arranges the busbar electrodes in such a manner that they cross the fingerline electrodes, and the ribbon is laminated on the busbar electrodes in a surface contact form. The present invention relates to a solar cell module capable of improving electrical characteristics between a ribbon and a busbar electrode.

A solar cell is a key element of photovoltaic power generation that directly converts sunlight into electricity, and is basically a diode composed of a p-n junction. In the process of converting sunlight into electricity by solar cells, when solar light enters into the silicon substrate of the solar cell, electron-hole pairs are generated, and electrons move to n layers and holes move to p layers by the electric field. Thus, photovoltaic power is generated between the pn junctions, and when a load or a system is connected to both ends of the solar cell, current flows to generate power.

On the other hand, a general solar cell has a structure in which a front electrode and a rear electrode are provided on the front and the rear, respectively, and as the front electrode is provided on the front surface, the light receiving area is reduced by the area of the front electrode. In order to solve the problem that the light receiving area is reduced, a back electrode solar cell has been proposed. The back electrode solar cell is characterized by maximizing the light receiving area of the solar cell by providing a (+) electrode and a (-) electrode on the back of the solar cell.

1 is a cross-sectional view of a back electrode solar cell of US Pat. No. 7,339,110. Referring to FIG. 1, a p-type doping layer (p +), which is a region where p-type impurity ions have been implanted, and an n-type doping layer (n +), which is a region where n-type impurity ions are implanted by thermal diffusion, are provided in a rear surface of a silicon substrate. A metal electrode is formed on the p-type doping layer p + and the n-type doping layer n +.

Meanwhile, the p-type doping layer (p +) 110 and the n-type doping layer (n +) 120 are arranged in an interdigitated structure with each other in the form of a comb (see FIG. 2), and busbars are disposed at both ends of the substrate. bar) is provided. The p-type doping layer (p +) 110 and the n-type doping layer (n +) 120 having a comb-tooth shape have a structure connected to the bus bar doping layers 150 and 160 located at both ends, respectively. Under this structure, holes (+) collected by the p-type doping layer (p +) 110 are transferred to the p-type busbar 170 via the p-type fingerline 130, and the n-type doping layer (n + The electrons (−) collected by the 120 are transferred to the n-type busbar 180 via the n-type fingerline 140 to perform photoelectric conversion of the solar cell.

However, the back electrode type solar cell having such a structure has a structure in which carriers collected in the fingerline are transferred to the busbar electrode along the fingerline, and thus the carrier transfer distance is far, and thus the process of transferring from the fingerline to the busbar electrode. Carriers are likely to die at

In order to prevent this, the area of each doping layer p + (n +) and fingerline may be increased, but in this case, the collection efficiency of each doping layer p + (n +) from inside the substrate is deteriorated. . In addition, a method of increasing the area of the busbar doping layer and the busbar electrode may be considered, but in this case, the carrier collection efficiency is reduced as much as the area where the busbar doping layer is provided.

The solar cell module to which the prior art back electrode type solar cell having the structure as described above is applied has the structure as shown in FIG. 3. Referring to FIG. 3, it can be seen that the neighboring busbar electrodes 170 and 180 are electrically connected through the ribbon 190. Meanwhile, in FIG. 3, the ribbon 192 and the bus bar electrodes 170 and 180 are in contact with each other in point contact form. The reason for this is as follows.

In the conventional back-electrode type solar cell, the finger lines 130 and 140 are disposed to correspond to the substrate length in order to improve light collection efficiency, and the busbar electrodes 170 and 180 are provided only at a portion of both ends of the substrate. In order to minimize the area of the busbar electrodes 170 and 180, the ribbon 190 and the busbar electrodes 170 and 180 are in contact with each other due to the structure (see FIG. 2). The battery also actually has the same structure as the solar cell of FIG. 3). In other words, the width of the busbars in areas not in contact with the ribbon 190 is minimized. As the ribbon 190 and the busbar electrodes 170 and 180 are in contact with each other in point contact form, there is a problem in that electrical characteristics of the solar cell module are deteriorated.

The present invention has been made to solve the above problems, omit the bus bar doping layer, the bus bar electrode is arranged in the form of crossing the fingerline electrode, the ribbon in the surface contact form on the bus bar electrode The purpose of the present invention is to provide a solar cell module that can be laminated to improve electrical characteristics between a ribbon and busbar electrodes.

In addition, the present invention has a further object to suppress the carrier disappearance by minimizing the carrier transport distance in the fingerline doping layer through the structure to omit the busbar doping layer, it is disposed in the substrate by reducing the width of the fingerline doping layer Another object is to improve the carrier collection efficiency in the substrate by maximizing the number of fingerline doped layers, and another object is to minimize the resistance loss by maximizing the contact area between the fingerline electrode and the busbar electrode.

The solar cell module according to the present invention for achieving the above object comprises a first solar cell, a second solar cell and a ribbon connecting the first solar cell and the second solar cell, the first solar cell Alternatively, the second solar cell may include a substrate, a plurality of n-type fingerline doping layers n + and a plurality of p-type fingerline doping layers p + disposed alternately inside the rear surface of the substrate, and the plurality of n-type fingers. A dielectric layer stacked on a substrate including a line doping layer (n +) and a plurality of p-type fingerline doping layers (p +), and an n-type fingerline doping layer (n +) formed on the n-type fingerline doping layer (n +). An n-type fingerline electrode having a length corresponding to (), a p-type fingerline electrode formed on the p-type fingerline doping layer (p +), and having a length corresponding to a p-type fingerline doping layer (p +), A first end of the p-type fingerline electrode and a second end of the p-type fingerline electrode An n-type busbar electrode provided on the polishing disk and the dielectric layer and electrically connected to the plurality of n-type fingerline electrodes, and a p-type busbar provided on the dielectric layer and electrically connected to the plurality of p-type fingerline electrodes. It characterized by comprising an electrode.

The first solar cell and the second solar cell have the same structure and are repeatedly arranged in a horizontal direction. In addition, the first solar cell and the second solar cell are disposed in a form in which the n-type busbar electrode of the first solar cell and the p-type busbar electrode of the second solar cell face each other, and the ribbon is the first solar cell. The n-type busbar electrode and the p-type busbar electrode of the second solar cell are contacted at the same time.

Each of the n-type fingerline doping layer n + and the p-type fingerline doping layer p + may be formed from one end of the substrate to the other end. In addition, one end of each of the n-type fingerline electrode and the p-type fingerline electrode may be a first end and the other end of the second end, and the insulating mask may include a first end of the p-type fingerline electrode and the n-type fingerline. The n-type fingerline electrode or the p-type fingerline electrode provided on the second end of the electrode and adjacent to the insulating mask is exposed.

a region (region A) in which the n-type fingerline electrodes are exposed and repeated, a region, a region in which the n-type fingerline electrode and the p-type fingerline electrode are both exposed and alternately disposed (a region B), and a p-type fingerline electrode And a repetitive and disposed region (region C) is provided, and an n-type busbar electrode connected to n-type fingerline electrodes is provided on a substrate rear surface of the region A, and is disposed on a substrate rear surface of the region C. A p-type busbar electrode is connected to the p-type fingerline electrodes.

The width of the n-type busbar electrode and the p-type busbar electrode is smaller than the width of the insulating mask. In addition, the line width of each of the n-type finger line electrode and the p-type finger line electrode is the same or smaller than the line width of the n-type finger line doping layer (n +), p-type finger line doping layer (p +). The plurality of n-type fingerline doping layers n + and the plurality of p-type fingerline doping layers p + are alternately disposed to be spaced apart or alternately disposed in contact with each other.

The solar cell module according to the present invention has the following effects.

As the busbar electrode is provided on the fingerline electrode, the area of the busbar electrode can be enlarged without considering the doping layer for the busbar, thereby improving the electrical characteristics between the busbar electrode and the fingerline electrode and the ribbon. The electrical resistance between the ribbon and the busbar electrode can be minimized by inducing contact between the busbar electrode and the surface contact.

In addition, since the busbar doping layer is not required, the fingerline doping layer may be configured in the region where the busbar doping layer is to be formed, thereby improving carrier collection efficiency. In addition, as the electrical characteristics of the busbar electrode are improved, the pattern width of the fingerline doping layer may be minimized, thereby increasing the carrier collection efficiency in the substrate.

1 is a cross-sectional view of a back electrode solar cell according to the prior art.
Figure 2 is a rear view of the back electrode solar cell according to the prior art.
3 is a plan view of a solar cell module according to the prior art.
Figure 4 is a perspective view of a back electrode solar cell according to an embodiment of the present invention.
Figure 5 is an exploded perspective view of a back electrode solar cell according to an embodiment of the present invention.
6 is a perspective view of a solar cell module according to an embodiment of the present invention.
7 is a plan view of a solar cell module according to an embodiment of the present invention.

Hereinafter, a solar cell module according to an embodiment of the present invention will be described in detail with reference to the drawings. The solar cell module according to an embodiment of the present invention is a combination of a plurality of back electrode solar cells, and each back electrode solar cell is electrically connected through a ribbon. Before describing the solar cell module of the present invention, the structure of the back electrode solar cell constituting the solar cell module of the present invention will be described.

Referring to FIG. 4, a back electrode solar cell according to an embodiment of the present invention first includes an n-type (or p-type) crystalline silicon substrate 410. A plurality of n-type fingerline doping layers (n +) 421 and a plurality of p-type fingerline doping layers (p +) 422 having a predetermined width and depth are alternately disposed inside the rear surface of the substrate 410. In this case, the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 may have the same shape and length, and the n-type fingerline doping layer (n +) ( Each of the 421 and the p-type fingerline doping layer (p +) 422 is disposed from one end of the substrate 410 to the other end. In addition, the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 may be arranged in a shape spaced apart from each other or in contact with each other. Meanwhile, a dielectric layer 430 is provided on the back surface of the substrate 410 including the plurality of n-type fingerline doping layers (n +) 421 and the plurality of p-type fingerline doping layers (p +) 422.

In addition, an n-type fingerline electrode 441 and a p-type fingerline electrode 442 are provided, and the n-type fingerline electrode 441 includes an n-type fingerline doping layer (n +) 421 and the p-type. The fingerline electrode 442 is electrically connected to the p-type fingerline doping layer n +. In this case, the line width of each of the n-type and p-type fingerline electrodes 441 and 442 is equal to the line width of the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422. It must be the same or smaller than it. In addition, the n-type fingerline electrode 441 has a length corresponding to the n-type fingerline doping layer (n +) 421, and the p-type fingerline electrode 442 is a p-type fingerline doping layer (p +) Have a length corresponding to 422.

An insulating mask 450 is locally provided on the n-type fingerline electrode 441 and the p-type fingerline electrode 442. As each of the n-type fingerline electrode 441 and the p-type fingerline electrode 442 has a predetermined length, both ends of the fingerline electrode may be defined as first and second stages, respectively. The insulating mask 450 is provided on the second end of the line electrode 441 and the first end of the p-type fingerline electrode 442. Here, the first end refers to a portion close to the first end, and the second end refers to a portion close to the second end.

As the insulating mask 450 is provided at each of the first and second ends, only the n-type fingerline electrodes 441 are exposed in the region A (region A) having the insulating mask 450 at the first end. In the region C region in which the insulating mask 150 is provided at the second end, only the p-type fingerline electrodes 442 are exposed to form the repeating and repeating arrangement. In the region (region B) between the second ends, both the n-type fingerline electrode 441 and the p-type fingerline electrode 442 are exposed and alternately arranged.

An n-type busbar electrode 461 is provided on the rear surface of the substrate 410 in the region A, and electrically connected to the n-type fingerline electrodes 441, and a p-type busbar is formed on the rear surface of the substrate 410 in the C region. An electrode 462 is provided to be electrically connected to the p-type fingerline electrodes 442.

In the back electrode solar cell according to the present invention as described above, it can be seen that the bus bar doping layer of the prior art is not provided, and the n-type fingerline doping layer (n +) ( 421 and a p-type fingerline doping layer (p +) 422. Accordingly, carriers (+) (−) may be collected in all regions of the substrate 410, and cell efficiency may be improved.

In addition, since the n-type and p-type busbar electrodes 462 are provided on the n-type and p-type fingerline electrodes 442 without the need for the busbar doping layer, the area of the busbar electrodes is selectively enlarged. This maximizes the contact area between the busbar electrode and the fingerline electrode, thereby improving the electrical characteristics between the busbar electrode and the fingerline electrode (in the past, one end of the fingerline electrode contacts the busbar electrode). Structure (see FIGS. 2 and 3). In addition, since the busbar electrode is directly provided on the fingerline electrode, there is no need to use a conductive paste containing a glass frit as in the prior art, and the busbar electrode may be formed only of a metal material having a low specific resistance. The resistance characteristics of the busbar electrodes can be improved.

As such, as the electrical characteristics of the busbar electrode are improved, there is room for reducing the widths of the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422, thereby providing a substrate. The collection distance of the carrier collected by the fingerline doping layer (n +) (p +) in the 410 may be reduced to increase the collection efficiency.

Above, the structure of the back electrode solar cell according to an embodiment of the present invention has been described, and the solar cell module according to an embodiment of the present invention configured by combining such a back electrode solar cell is as follows. same.

6 and 7, the solar cell module according to the present invention includes a plurality of back electrode solar cells 400, and the plurality of back electrode solar cells 400 are disposed adjacent to each other. do. In addition, the plurality of back electrode solar cells 400 may be configured such that a back electrode solar cell having the same structure is repeatedly arranged in a horizontal direction, and busbar electrodes face each other. For example, when the first (back electrode type) solar cell and the second (back electrode type) solar cell are disposed adjacent to each other, the n-type busbar electrode 461 of the first solar cell and the p-type of the second solar cell are disposed. The bus bars 462 electrodes face each other.

In a state in which the first solar cell 400 and the second solar cell 400 are adjacent to each other, the first solar cell 400 and the second solar cell 400 are connected via a ribbon 500. . Specifically, the ribbon 500 is in contact with the n-type busbar electrode 461 of the first solar cell 400 and in contact with the p-type busbar electrode 462 of the second solar cell 400. It is provided in the form. In this case, each of the n-type busbar electrode 461 and the p-type busbar electrode 462 is provided in a form having a predetermined area at both ends of the substrate, the n-type busbar electrode (of the first solar cell) (461) Since the ribbon 500 is stacked on the p-type busbar electrode 462 of the second solar cell, the ribbon 500 includes an n-type busbar electrode 461 and a p-type busbar ( 462) a surface contact with a substantial portion of the electrode. Meanwhile, the contact between the ribbon 500 and the bus bar electrodes 461 and 462 may be implemented by thermocompression.

In the conventional case, since the busbar electrode area is minimized, the busbar electrode and the ribbon are in point contact, whereas in the present invention, a back electrode type solar cell does not require a busbar doping layer and a fingerline electrode. As the busbar electrode is provided on the structure, the area of the busbar electrode can be selectively enlarged, thereby guiding the contact between the busbar electrode and the ribbon in the form of surface contact, thereby maximizing the contact area. . In addition, in the conventional case, the ribbon has to be processed into a complicated shape for point contact (see FIG. 3), but in the case of the present invention, it may be processed into a simple shape such as a square.

410: n-type or p-type crystalline silicon substrate
421: n-type fingerline doping layer (n +) 422: p-type fingerline doping layer (p +)
430: dielectric layer 441: n-type finger line electrode
442: p-type finger line electrode 450: insulating mask
461: n-type busbar electrode 461: p-type busbar electrode
500: ribbon
A region: region where n-type fingerline electrodes are repeatedly arranged
B area: an area where n-type finger line electrodes and p-type finger line electrodes are alternately arranged
C region: region where p-type fingerline electrodes are repeated

Claims

It comprises a first solar cell, a second solar cell and a ribbon connecting the first solar cell and the second solar cell,
The first solar cell or the second solar cell,
Board;
A plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) disposed alternately inside a rear surface of the substrate;
A dielectric layer stacked on the substrate including the plurality of n-type fingerline doping layers (n +) and the plurality of p-type fingerline doping layers (p +);
An n-type fingerline electrode formed on the n-type fingerline doping layer n + and having a length corresponding to the n-type fingerline doping layer n +, and formed on the p-type fingerline doping layer p + a type fingerline electrode having a length corresponding to the p-type fingerline doping layer p +;
An insulating mask provided on the first end of the p-type fingerline electrode and the second end of the p-type fingerline electrode; And
An n-type busbar electrode provided on the dielectric layer and disposed in a direction perpendicular to the plurality of n-type fingerline electrodes and electrically connected to the plurality of n-type fingerline electrodes; And a p-type busbar electrode disposed in a direction perpendicular to a fingerline electrode and electrically connected to the plurality of p-type fingerline electrodes.
The first solar cell and the second solar cell are repeatedly arranged so that each busbar electrode is horizontal on a different line, and the busbar electrodes of different conductivity types face each other.
The ribbon is formed in a quadrangular solar cell module, characterized in that the surface contact with the busbar electrode of the first solar cell and the busbar electrode of the second solar cell adjacent to each other.

The solar cell module of claim 1, wherein the first solar cell and the second solar cell have the same structure and are repeatedly arranged in a horizontal direction.

delete

The solar cell module of claim 1, wherein each of the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +) is formed from one end of the substrate to the other end.

2. The method of claim 1, wherein one end of each of the n-type fingerline electrode and the p-type fingerline electrode is a first end and the other end is a second end, and the insulating mask is formed on the first end of the p-type fingerline electrode. on the second end of the n-type fingerline electrode,
And the n-type fingerline electrode or the p-type fingerline electrode adjacent to the insulating mask.

The method of claim 5, wherein the n-type fingerline electrodes are exposed and repeated and disposed (region A), and the n-type fingerline electrode and the p-type fingerline electrode are both exposed and alternately disposed and disposed (region B). and a region (region C) in which p-type fingerline electrodes are exposed and repeatedly arranged.
An n-type busbar electrode connected to n-type fingerline electrodes is provided on a substrate rear surface of the region A, and a p-type busbar electrode connected to p-type fingerline electrodes is provided on a substrate rear surface of the region C. Solar cell module characterized in that the.

The solar cell module of claim 1, wherein widths of the n-type busbar electrode and the p-type busbar electrode are smaller than a width of the insulating mask.

The line width of each of the n-type fingerline electrode and the p-type fingerline electrode is equal to or greater than that of the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +). Solar cell module, characterized in that small.

The solar cell of claim 1, wherein the plurality of n-type fingerline doping layers n + and the plurality of p-type fingerline doping layers p + are alternately arranged to be spaced apart or alternately arranged in contact with each other. module.