WO2012081813A1 - Back contact solar cell and method for fabricating same - Google Patents

Abstract

The present invention relates to a back contact solar cell in which the carrier transfer distance may be minimized within a finger line doped layer through a structure in which a doped layer for a bus bar is omitted to restrain carrier decay; and to a method for fabricating same. According to the present invention, the back contact solar cell includes: a substrate; a plurality of n-type finger line doped layers (n+) and a plurality of p-type finger line doped layers (p+) which are alternately disposed within the back surface of the substrate; a dielectric layer stacked on the substrate including the plurality of n-type finger line doped layers (n+) and the plurality of p-type finger line doped layers (p+); an n-type finger line electrode disposed on a portion of each of the n-type finger line doped layers (n+); a p-type finger line electrode disposed on a portion of each of the p-type finger line doped layers (p+); an n-type bus bar electrode disposed on the dielectric layer and electrically connected to the plurality of n-type finger line electrodes; and a p-type bus bar electrode disposed on the dielectric layer and electrically connected to the plurality of p-type finger line electrodes. The area (area A) on which the n-type finger line electrodes are repeatedly disposed, the area (area B) on which the n-type finger line electrodes and the p-type finger line electrodes are alternately disposed, and the area (area C) on which the p-type finger line electrodes are repeatedly disposed are provided. Also, the n-type bus bar electrode may be disposed on area A of the back surface of the substrate, and the p-type bus bar electrode may be disposed on area C of the back surface of the substrate.

Description

Back electrode solar cell and manufacturing method thereof

The present invention relates to a back-electrode solar cell and a method of manufacturing the same, and more specifically, through the structure of omitting the bus bar doping layer, it is possible to suppress the carrier disappearance by minimizing the carrier transfer distance in the fingerline doping layer. The present invention relates to a back electrode solar cell and a method of manufacturing the same.

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 from the fingerline are transferred to the busbar doping layer, so that the carrier transport distance is far, and the carrier in the process of being transferred from the fingerline to the busbar doping layer Are likely to disappear. 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, there is a problem that the carrier collection efficiency is lowered as much as the area provided with the bus bar doping layer.

The present invention has been made to solve the above problems, and through the structure to omit the bus bar doping layer, the back-electrode type that can suppress the disappearance of the carrier by minimizing the carrier transport distance in the fingerline doping layer Its purpose is to provide a battery and a method of manufacturing the same.

In addition, the present invention has another object to improve the carrier collection efficiency in the substrate by maximizing the number of the fingerline doping layer disposed in the substrate by reducing the width of the fingerline doping layer, the contact between the fingerline electrode and the busbar electrode Another goal is to minimize resistive losses by maximizing the area.

In order to achieve the above object, a back electrode solar cell according to the present invention includes a substrate, a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers alternately disposed inside the back of the substrate ( p +), a dielectric layer laminated on a substrate including the plurality of n-type fingerline doping layers (n +) and the plurality of p-type fingerline doping layers (p +), and a portion of the n-type fingerline doping layer (n +). An n-type fingerline electrode formed on a region, a p-type fingerline electrode formed on a portion of the p-type fingerline doping layer p +, and a plurality of n-type fingerline electrodes provided on the dielectric layer to electrically And a p-type busbar electrode connected to the n-type busbar electrode connected to the dielectric layer and electrically connected to the plurality of p-type fingerline electrodes.

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.

One end of each of the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +) is a first end and the other end is a second end, and each of the n-type fingerline electrode and the p-type fingerline electrode The length is shorter than the length of each of the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), and the n-type fingerline electrode is a first end of the n-type fingerline doping layer (n +). The p-type fingerline electrode may be biased at a second end of the p-type fingerline doping layer p +.

The region where the n-type fingerline electrodes are repeated and arranged (region A), the region where the n-type fingerline electrode and the p-type fingerline electrode are alternately arranged and arranged (region B), and the p-type fingerline electrodes are repeatedly arranged and arranged. An area (region C) may be provided, an n-type busbar electrode may be provided on the substrate rear surface of the region A, and a p-type busbar electrode may be provided on the substrate rear surface of the region C.

The line width of each of the n-type fingerline electrode and the p-type fingerline electrode is preferably equal to or smaller than that of the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +). In addition, the plurality of n-type fingerline doping layers n + and the plurality of p-type fingerline doping layers p + may be alternately disposed to be spaced apart or alternately disposed in contact with each other.

The dielectric layer repeatedly includes a unit pattern exposing a portion of an n-type fingerline doping layer (n +) or a p-type fingerline doping layer (n +), wherein the n-type fingerline electrode and the p-type fingerline electrode are the unit pattern. The n-type fingerline doping layer n + or the p-type fingerline doping layer n + exposed by the pattern is electrically connected.

In the method of manufacturing a back-electrode solar cell according to the present invention, a method of preparing a substrate and alternating a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) inside the back of the substrate are performed. And forming a dielectric layer on a back surface of the substrate, electrically forming a portion of the n-type fingerline doping layer n + and a portion of the p-type fingerline doping layer p +, respectively. Forming an n-type fingerline electrode and a p-type fingerline electrode to be connected and electrically connecting the n-type busbar electrode and the plurality of p-type fingerline electrodes on the dielectric layer to be electrically connected to the plurality of n-type fingerline electrodes. It characterized in that it comprises a step of forming a p-type busbar electrode connected to.

Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to a portion of the n-type fingerline doping layer (n +) and a portion of the p-type fingerline doping layer (p +), respectively, applying a conductive paste on a dielectric layer corresponding to a portion of the n-type and p-type fingerline doping layer (n +), and firing the conductive paste to form n-type and p-type fingerline electrodes, And a metal material through the dielectric layer to be electrically connected to the n-type and p-type fingerline doping layers (n +) (p +).

The forming of the n-type fingerline electrode and the p-type fingerline electrode electrically connected to the partial region of the n-type fingerline doping layer n + and the partial region of the p-type fingerline doping layer p + may be performed. Etching and removing a portion of the dielectric layer to expose a portion of the n-type fingerline doping layer (n +) and a portion of the p-type fingerline doping layer (p +), and the exposed n-type and p-type fingers. And forming a n-type fingerline electrode and a p-type fingerline electrode by laminating a metal material on the line doping layer (n +) (p +).

The back electrode solar cell and a method of manufacturing the same according to the present invention have the following effects.

Since the busbar doping layer is not required, a fingerline doping layer may be formed in a region where the busbar doping layer is to be formed, thereby improving carrier collection efficiency.

As the busbar electrode is provided on the fingerline electrode, the area of the busbar electrode can be enlarged without consideration of the busbar doping layer, thereby improving the electrical characteristics between the busbar electrode and the fingerline electrode. . As such, 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 perspective view of a back electrode solar cell according to a first embodiment of the present invention;

Figures 4a to 4e is a process chart for explaining the manufacturing method of the back-electrode solar cell according to the first embodiment of the present invention.

5 is a perspective view of a back electrode solar cell according to a second embodiment of the present invention.

6A to 6F are flowcharts illustrating a method of manufacturing a back electrode solar cell according to a second embodiment of the present invention.

7 is a perspective view of a back electrode solar cell according to an embodiment of the present invention.

8A to 8F are process charts for explaining a method for manufacturing a back electrode solar cell according to an embodiment of the present invention.

9 is a perspective view of a back electrode solar cell according to an embodiment of the present invention.

10a to 10e is a process chart for explaining a method for manufacturing a back-electrode solar cell according to an embodiment of the present invention.

Hereinafter, a back electrode solar cell and a method of manufacturing the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, the back electrode solar cell according to the first 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. 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 is provided on a portion of the n-type fingerline doping layer (n +) 421, and a p-type is formed on a portion of the p-type fingerline doping layer (p +) 422. Fingerline electrode 442 is provided. 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.

When both ends of each of the n-type and p-type fingerline doping layers n + and p + are defined as first and second ends, the n-type fingerline electrode 441 may be an n-type fingerline doping layer n + ( The p-type fingerline electrode 442 is formed on an area proximate to the first end of the 421, and the p-type fingerline electrode 442 is formed on an area proximate the first end of the n-type fingerline doping layer (n +) 421. Accordingly, the back surface of the substrate 410 is an A region in which n-type finger lines are repeated and arranged, an N region in which n-type finger lines and a p-type finger line are alternately arranged, a B region in which p-type finger lines are repeatedly arranged and arranged in a C region Can be distinguished.

The n-type busbar electrode 451 is provided on the rear surface of the substrate 410 in the A region, and the p-type busbar electrode 452 is provided on the rear surface of the substrate 410 in the C region.

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 452 are provided on the n-type and p-type fingerline electrodes 442 without the need for a 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 FIG. 2). 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, the widths of the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 may be reduced, thereby allowing the substrate ( The collection distance of the carrier collected by the fingerline doping layer (n +) (p +) inside the 410 may be reduced to increase the collection efficiency.

Next, a manufacturing method of the back electrode solar cell according to the first embodiment of the present invention will be described. On the other hand, the back electrode solar cell according to the present invention is characterized in the structure of the finger line doping layer, finger line and bus bar provided on the back of the substrate 410, the structure provided on the back of the substrate 410 (fingerline A method of forming the doping layer, the finger line, and the bus bar will be described below, and a detailed description of the structure formed on the entire surface of the substrate 410 will be omitted. Therefore, the manufacturing process for the components required for the back-electrode solar cell in addition to the finger line doping layer, finger line and bus bar can be selectively applied.

First, as shown in FIG. 4A, an n-type or p-type crystalline silicon substrate 410 is prepared. Then, an n-type fingerline doping layer (n +) 421 and a p-type fingerline doping layer (p +) 422 having a predetermined depth are alternately formed on the rear surface of the substrate 410. That is, the plurality of n-type fingerline doping layers (n +) 421 and the plurality of p-type fingerline doping layers (p +) 422 are alternately disposed, and the n-type fingerline doping layers (n +) 421 The p-type fingerline doping layers (p +) 422 are disposed at regular intervals. Further, each fingerline doping layer n + (p +) is formed from one end of the substrate 410 to the other end, so that the length of each fingerline doping layer n + (p +) is the length of the substrate 410. Forms the equivalent of Meanwhile, the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 may be disposed to be spaced apart from each other or in contact with each other.

The n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 may be sequentially and independently formed, and may be formed using screen printing, spraying, or ion implantation. have. For example, in the case of using a screen printing method, an n-type impurity layer including n-type impurity ions is formed on a region where an n-type fingerline doping layer (n +) 421 is to be formed, and then n-type impurity through heat treatment. The ions are diffused into the substrate 410 to form the n-type fingerline doped layer (n +) 421, and the p-type fingerline doped layer (p +) 422 may also be formed by the same method.

In the state in which the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 that are alternately arranged on the rear surface of the substrate 410 are formed, the substrate ( The dielectric layer 430 is formed on the front surface of the rear surface. The dielectric layer 430 may be selectively shorted to a bus bar and a n-type fingerline doped layer (n +) 421 or a p-type fingerline doped layer (p +) 422 formed through a subsequent process. It serves to block. In addition, the dielectric layer 430 may be formed using a chemical vapor deposition process or the like, and may be formed of a silicon oxide film (SiO ₂ ) or a silicon nitride film (SiN _x ).

In this state, a plurality of n-type fingerline electrodes 441 and a plurality of p-type fingerline electrodes 442 are formed on the dielectric layer 430 (see FIG. 4D). The n-type fingerline electrode 441 is provided on a region where an n-type fingerline doping layer (n +) 421 is formed, and the p-type fingerline electrode 442 is a region where a fingerline doping layer (n +) is formed. The n-type fingerline electrode 441 is electrically connected to an n-type fingerline doping layer (n +) 421, and the p-type fingerline electrode 442 is a p-type fingerline doping layer ( p +) 422 is electrically connected.

The plurality of n-type fingerline electrodes 441 (or the plurality of p-type fingerline electrodes 442) are repeatedly arranged and disposed on a plurality of n-type fingerline doping layer (n +) 421 regions. Specifically, the n-type fingerline electrode 441 is disposed to fill only a part of the region of the n-type fingerline doping layer (n +) 421, and the form is repeated. That is, the n-type fingerline electrode 441 is provided only in a region corresponding to a part of the entire length of the n-type fingerline doping layer (n +) 421, and thus the n-type fingerline doping layer (n +) 421. The n-type fingerline electrode 441 is not provided in a part of the region. Similarly, the p-type fingerline doping layer (p +) 422 has a structure in which the p-type fingerline electrode 442 is provided only in a portion of the region.

On the other hand, each of the plurality of n-type finger line electrode 441 and the plurality of p-type finger line electrode 442 is disposed in a form biased to different ends of the substrate 410. For example, the n-type fingerline doping layer (n +) 421 and the p-type fingerline doping layer (p +) 422 are respectively formed in the first and second stages (the first and second ends are the fingerline doping layers ( n +) (p +) both ends), the n-type fingerline electrode 441 is disposed in a form biased to the first end of the n-type fingerline doping layer (n +) 421, and the p-type fingerline The electrode 442 is disposed in a form biased to the second end of the p-type fingerline doping layer (p +) 422. Accordingly, only the n-type fingerline electrodes 441 are repeatedly arranged and arranged in the region A region close to the first end, and the p-type fingerline electrode 442 in the region C region close to the second end. ) Only repeats and forms. On the other hand, in the region B region between the first stage and the second stage, the n-type fingerline electrode 441 and the p-type fingerline electrode 442 are alternately arranged.

Two methods may be used to form the n-type fingerline electrode 441 and the p-type fingerline electrode 442. First, the first method is described as follows. In the state where the dielectric layer 430 is stacked, as shown in FIG. 4C, a portion of the dielectric layer 430 is etched and removed. The region where the dielectric layer 430 is etched corresponds to the region where the n-type and p-type fingerline electrodes 442 are formed. That is, a portion of the n-type fingerline doped layer (n +) 421 and a portion of the p-type fingerline doped layer (p +) 422 are exposed. At this time, a portion of the exposed n-type fingerline doping layer (n +) 421 is a region close to the first end, and a portion of the exposed p-type fingerline doping layer (p +) 422 is the second region. It is near to the stage. In this state, when the metal material is deposited on the exposed n-type and p-type fingerline doping layers n + and p +, the n-type fingerline electrode 441 and the p-type fingerline electrode 442 are completed ( See FIG. 4D). The metal material may be laminated using screen printing or the like.

Meanwhile, in etching and removing a portion of the dielectric layer, only a part of the fingerline doping layer may be exposed in addition to the method of exposing all of the fingerline doping layers n + and p + as shown in FIG. 4C. In this case, the dielectric layer may be selectively etched so that the exposure pattern having a predetermined shape is repeated. In detail, the dielectric layer may be etched and removed so that unit patterns of circular, square, and oval are repeated to remove the finger line doping layer (n +) ( a portion of p +) may be selectively exposed. Accordingly, the fingerline electrodes 441 and 442 have a structure in which the fingerline doping layers n + and p + are partially exposed.

The second method is described as follows. Screen printing a conductive paste on the dielectric layer 430 and then firing the metal component in the conductive paste to fire-through the dielectric layer 430 so that the n-type and p-type fingerline electrodes 442 are formed. The n-type fingerline electrode 441 is connected to the n-type fingerline doping layer (n +) 421 and the p-type fingerline is connected to the p-type fingerline doping layer (p +) 422. (See FIG. 4D). At this time, a region where the conductive paste is printed is a partial region of the n-type and p-type fingerline doping layers (p +) 421 and 422, and a portion of the n-type fingerline doping layer (n +) 421 is The portion is close to the first end, and a portion of the p-type fingerline doping layer (p +) 422 is a portion close to the second end.

Looking at the planar state of the back surface of the substrate 410 on which the n-type fingerline electrode 441 and the p-type fingerline electrode 442 are formed, as described above, it can be divided into A region, B region, and C region, and A region is The region where the n-type fingerline electrodes 441 are repeated and disposed, the region B, the region where the n-type fingerline electrode 441 and the p-type fingerline electrode 442 are alternately arranged, and the region C, is the p-type fingerline electrode 442 are defined as repeating, arranged regions.

In this state, as shown in FIG. 4E, when the conductive paste is applied onto the substrates 410 of the A region and the C region, and then heat-treated, the n-type busbar electrode 451 is formed in the A region, and the C region. The p-type busbar electrode 452 is formed thereon. As only the n-type fingerline electrodes 441 are repeatedly arranged and disposed in the A region, the n-type busbar electrode 451 is electrically connected to only the n-type fingerline electrodes 441, and in the C region, p As only the type fingerline electrodes 442 are repeatedly arranged and arranged, the p-type busbar electrode 452 is electrically connected to only the p-type fingerline electrodes 442.

Next, a back electrode solar cell and a method of manufacturing the same according to a second embodiment of the present invention will be described in detail.

Referring to FIG. 5, the back electrode solar cell according to the second embodiment of the present invention first includes an n-type (or p-type) crystalline silicon substrate 510. A plurality of n-type fingerline doping layers (n +) 521 and a plurality of p-type fingerline doping layers (p +) 522 having a predetermined width and depth are alternately disposed inside the rear surface of the substrate 510. In this case, the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522 may have the same shape and length, and the n-type fingerline doping layer (n +) ( Each of 521 and p-type fingerline doping layer (p +) 522 is disposed from one end of the substrate 510 to the other end. Meanwhile, a dielectric layer 530 is provided on the back surface of the substrate 510 including the plurality of n-type fingerline doping layers (n +) 521 and the plurality of p-type fingerline doping layers (p +) 522.

In addition, an n-type fingerline electrode 541 and a p-type fingerline electrode 542 are provided, and the n-type fingerline electrode 541 is an n-type fingerline doping layer (n +) 521 and the p-type The fingerline electrode 542 is electrically connected to the p-type fingerline doping layer n +. At this time, the line width of each of the n-type and p-type fingerline electrodes 541 and 542 is equal to the line width of the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522. It must be the same or smaller than it.

An insulating mask 550 is locally provided on the n-type fingerline electrode 541 and the p-type fingerline electrode 542. As each of the n-type fingerline electrode 541 and the p-type fingerline electrode 542 has a predetermined length, both ends of the fingerline electrode may be defined as first and second ends, respectively. The insulating mask 550 is provided on the second end of the line electrode 541 and the first end of the p-type fingerline electrode 542. 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 masks 550 are provided at the first and second ends, only n-type fingerline electrodes 541 are exposed in the area AA where the insulating mask 150 is provided at the first end. In the region (CC region) in which the insulating mask 150 is provided at the second end, only the p-type fingerline electrodes 542 are exposed and repeatedly formed and arranged. In the region between the second ends (BB region), both the n-type fingerline electrode 541 and the p-type fingerline electrode 542 are exposed and alternately arranged.

An n-type busbar electrode 561 is provided on the back surface of the substrate 510 in the AA region to be electrically connected to the n-type fingerline electrodes 541, and a p-type busbar is formed on the back surface of the substrate 510 in the CC region. An electrode 562 is provided and electrically connected to the p-type fingerline electrodes 542.

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 +) ( 521 and a p-type fingerline doping layer (p +) 522. Accordingly, carriers (+) (−) may be collected in all regions of the substrate 510, and cell efficiency may be improved.

In addition, since the n-type and p-type busbar electrodes 562 are provided on the n-type and p-type fingerline electrodes 542 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 FIG. 2). 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 to reduce the widths of the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522, thereby providing a substrate. The collection distance of the carrier collected by the fingerline doping layer (n +) (p +) in the 510 may be reduced to increase the collection efficiency.

Next, a method of manufacturing a back electrode solar cell according to a second embodiment of the present invention will be described. On the other hand, the back electrode solar cell according to the present invention is characterized in the structure of the finger line doping layer, finger line and bus bar provided on the back of the substrate 510, the structure provided on the back of the substrate 510 (fingerline A method of forming the doping layer, the finger line, and the bus bar will be described below, and a detailed description of the structure formed on the entire surface of the substrate 510 will be omitted. Therefore, the manufacturing process for the components required for the back-electrode solar cell in addition to the finger line doping layer, finger line and bus bar can be selectively applied.

First, as shown in FIG. 6A, an n-type or p-type crystalline silicon substrate 510 is prepared. Thereafter, an n-type fingerline doping layer (n +) 521 and a p-type fingerline doping layer (p +) 522 having a predetermined depth are alternately formed on the rear surface of the substrate 510. That is, the plurality of n-type fingerline doping layers (n +) 521 and the plurality of p-type fingerline doping layers (p +) 522 are alternately disposed, and the n-type fingerline doping layers (n +) 521 are alternately arranged. The p-type fingerline doping layers (p +) 522 are disposed at regular intervals. Further, each fingerline doping layer n + (p +) is formed from one end of the substrate 510 to the other end, so that the length of each fingerline doping layer n + (p +) is the length of the substrate 510. Forms the equivalent of Meanwhile, the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522 may be disposed to be spaced apart from each other or in contact with each other.

The n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522 may be sequentially and independently formed, and may be formed using screen printing, spraying, or ion implantation. have. For example, when using a screen printing method, an n-type impurity layer including n-type impurity ions is formed on a region where an n-type fingerline doping layer (n +) 521 is to be formed, and then n-type impurity is formed through heat treatment. N-type fingerline doping layers (n +) 521 may be formed by allowing ions to diffuse into the substrate 510, and p-type fingerline doping layers (p +) 522 may also be formed by the same method.

With the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522 alternately arranged on the back surface of the substrate 510, the substrate ( 510 forms a dielectric layer 530 on the front surface of the back. The dielectric layer 530 may be selectively shorted with a bus bar and a n-type fingerline doped layer (n +) 521 or a p-type fingerline doped layer (p +) 522 formed through a subsequent process. It serves to block. In addition, the dielectric layer 530 may be formed using a chemical vapor deposition process, a physical vapor deposition process, thermally grown silicon oxide, atomic layer deposition, etc. , Silicon nitride film (SiNx), aluminum oxide film (Al2O3), silicon carbide film (SiC), or an oxide-based or non-oxide dielectric material, and may be composed of a double or multi-layer structure.

In this state, the n-type fingerline electrode 541 and the p-type fingerline are electrically connected to the n-type fingerline doping layer (n +) 521 and the p-type fingerline doping layer (p +) 522, respectively. An electrode 542 is formed (see FIG. 6D). The n-type fingerline electrode 541 and the p-type fingerline electrode 542 may be formed using two methods.

In the first method, an n-type fingerline doping layer (n +) 521 and a p-type fingerline doping layer (p +) 522 are formed by etching and removing a portion of the dielectric layer 530 while the dielectric layer 530 is stacked. After exposing (see FIG. 6C), a metal material is deposited on the exposed n-type fingerline doping layer (n +) 521 and p-type fingerline doping layer (p +) 522 (see FIG. 6D) n The type finger line electrode 541 and the p type finger line are completed. In this case, the metal material may be laminated using screen printing or the like.

Meanwhile, in etching and removing a portion of the dielectric layer, only a portion of the fingerline doping layer may be exposed in addition to the method of exposing all of the fingerline doping layers n + and p + as shown in FIG. 6C. In this case, the dielectric layer may be selectively etched so that the exposure pattern having a predetermined shape is repeated. In detail, the dielectric layer may be etched and removed so that unit patterns of circular, square, and oval are repeated to remove the finger line doping layer (n +) ( a portion of p +) may be selectively exposed. Accordingly, the fingerline electrodes 541 and 542 have a structure in which the fingerline doping layers n + and p + are partially exposed.

The second method is as follows. Screen printing a conductive paste on the dielectric layer 530 and then firing the metal component in the conductive paste to fire-through the dielectric layer 530 to n-type and p-type fingerline electrodes 541. In addition, the n-type fingerline electrode 541 is connected to the n-type fingerline doping layer (n +) 521 and the p-type fingerline electrode 542 is a p-type fingerline doping layer ( p +) 522 (see FIG. 6D).

With the n-type fingerline electrode 541 and the p-type fingerline electrode 542 formed, the insulating mask 550 is locally applied on the n-type fingerline electrode 541 and the p-type fingerline electrode 542. Laminated. As each of the n-type fingerline electrode 541 and the p-type fingerline electrode 542 has a predetermined length, both ends of the fingerline electrode may be defined as first and second ends, respectively. The insulating mask 550 is stacked on the second end of the line electrode 541 and the first end of the p-type fingerline electrode 542 (see FIG. 6E). 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 550 is provided at each of the first and second ends, only the n-type fingerline electrodes 541 are exposed and repeatedly arranged in the area AA where the first end is provided. In the region where the second end is provided (CC region), only the p-type fingerline electrodes 542 are exposed and repeated, and in the region between the first and second ends, n Both the type fingerline electrode 541 and the p-type fingerline electrode 542 are exposed and alternately arranged.

Looking at the planar state of the back surface of the substrate 510 on which the n-type fingerline electrode 541 and the p-type fingerline electrode 542 are formed, as described above, it can be divided into the AA region, the BB region, and the CC region. The region where the n-type fingerline electrodes 541 are exposed and repeated and arranged, and the BB region, the region where the n-type fingerline electrode 541 and the p-type fingerline electrode 542 are both exposed and alternately disposed and the CC region The p-type fingerline electrodes 542 are defined as regions that are exposed and arranged repeatedly.

In this state, as shown in FIG. 6F, when the conductive paste is applied onto the substrate 510 of the AA region and the CC region, and then heat-treated, the n-type busbar electrode 561 is formed in the AA region, and the CC region. The p-type busbar electrode 562 is formed thereon. As only the n-type fingerline electrodes 541 are exposed and repeatedly disposed in the AA region, the n-type busbar electrode 561 is electrically connected only to the n-type fingerline electrodes 541 and the CC region. Since only the p-type fingerline electrodes 542 are exposed and arranged repeatedly, the p-type busbar electrode 562 is electrically connected to only the p-type fingerline electrodes 542. Meanwhile, the width D ₂ of the n-type busbar electrode 561 and the p-type busbar electrode 562 should be smaller than the width of the insulating mask 550. When the width of the busbar electrode is larger than the width D ₁ of the insulating mask 550, different conductive types (<n-type busbar electrode 561 and p-type fingerline electrode 542> or <p-type bus) This is because the bar electrode 562 and the n-type fingerline electrode 541 are short-circuited.

Next, a back electrode solar cell and a method of manufacturing the same according to a third embodiment of the present invention will be described in detail.

Referring to FIG. 7, the back electrode solar cell according to the third embodiment of the present invention first includes an n-type (or p-type) crystalline silicon substrate 610. A plurality of n-type fingerline doping layers (n +) 621 and a plurality of p-type fingerline doping layers (p +) 622 having a predetermined width and depth are alternately disposed inside the rear surface of the substrate 610. In this case, the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622 may have the same shape and length, and the n-type fingerline doping layer (n +) ( Each of the 621 and the p-type fingerline doping layer (p +) 622 is disposed from one end of the substrate 610 to the other end. Meanwhile, a dielectric layer 630 is provided on the back surface of the substrate 610 including the plurality of n-type fingerline doping layers (n +) 621 and the plurality of p-type fingerline doping layers (p +) 622.

In addition, an n-type fingerline electrode 641 and a p-type fingerline electrode 642 are provided, and the n-type fingerline electrode 641 is an n-type fingerline doping layer (n +) 621 and the p-type The fingerline electrode 642 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 641 and 642 is equal to the line width of the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622. It must be the same or smaller than it.

An insulating mask 650 is locally provided on the n-type fingerline electrode 641 and the p-type fingerline electrode 642. Specifically, an insulating mask 650 having a predetermined area on the n-type fingerline electrode 641 and the p-type fingerline electrode 642 is an n-type fingerline electrode 641 and a p-type fingerline electrode 642. Is provided at regular intervals along the longitudinal direction of the. The insulating masks 650 provided on each n-type fingerline electrode 641 form a structure that is repeated and arranged in a horizontal direction, and the insulating masks 650 provided on each p-type fingerline electrode 642 also have a horizontal direction. It forms a structure that is repeated and arranged.

In addition, a horizontal area (first horizontal area AAA) including the insulating masks 650 of each n-type fingerline and a horizontal area (second horizontal area, BBB) including the insulating masks 650 of each p-type fingerline ) Are different from each other and do not overlap. Accordingly, only n-type fingerline electrodes 641 are exposed in the first horizontal area AAA, and only p-type fingerline electrodes 642 are exposed in the second horizontal area BBB.

An n-type busbar electrode 661 is provided on the first horizontal area AAA to be electrically connected to the n-type fingerline electrodes 641 exposed in the first horizontal area, and the second horizontal area BBB. The p-type busbar electrode 662 is provided and electrically connected to the exposed p-type fingerline electrodes 642. In this case, the width D ₂ of the n-type busbar electrode 661 and the p-type busbar electrode 662 should be smaller than the width D ₁ of the insulating mask 650.

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 +) ( 621 and a p-type fingerline doping layer (p +) 622. Accordingly, carriers (+) (−) may be collected in all regions of the substrate 610, and cell efficiency may be improved.

In addition, since the n-type and p-type busbar electrodes 662 are provided on the n-type and p-type fingerline electrodes 642 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 FIG. 2). 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 +) 621 and the p-type fingerline doping layer (p +) 622, thereby providing a substrate. In 610, the collection distance of the carrier collected by the fingerline doping layer n + (p +) may be reduced to increase the collection efficiency.

Next, a method of manufacturing a back electrode solar cell according to a third embodiment of the present invention will be described. On the other hand, the back electrode solar cell according to the present invention is characterized in the structure of the finger line doping layer, finger line and bus bar provided on the back of the substrate 610, the structure provided on the back of the substrate 610 (finger line A method of forming the doping layer, the finger line, and the bus bar will be described below, and a detailed description of the structure formed on the entire surface of the substrate 610 will be omitted. Therefore, the manufacturing process for the components required for the back-electrode solar cell in addition to the finger line doping layer, finger line and bus bar can be selectively applied.

First, as shown in FIG. 8A, an n-type or p-type crystalline silicon substrate 610 is prepared. Thereafter, an n-type fingerline doping layer (n +) 621 and a p-type fingerline doping layer (p +) 622 having a predetermined depth are alternately formed on the rear surface of the substrate 610. That is, the plurality of n-type fingerline doping layers (n +) 621 and the plurality of p-type fingerline doping layers (p +) 622 are alternately arranged. In addition, each fingerline doping layer n + (p +) is formed from one end of the substrate 610 to the other end, so that the length of each fingerline doping layer n + (p +) is the length of the substrate 610. Forms the equivalent of Meanwhile, the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622 may be disposed to be spaced apart at regular intervals or to be in contact with each other.

The n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622 may be sequentially and independently formed, and may be formed using screen printing, spraying, or ion implantation. have. For example, in the case of using a screen printing method, an n-type impurity layer including n-type impurity ions is formed on a region where an n-type fingerline doping layer (n +) 621 is to be formed, and then an n-type impurity is formed by heat treatment. By allowing ions to diffuse into the substrate 610, an n-type fingerline doping layer (n +) 621 may be formed, and a p-type fingerline doping layer (p +) 622 may also be formed by the same method.

In the state where the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622 are alternately disposed on the back surface of the substrate 610, the substrate ( 610 to form a dielectric layer 630 on the front surface of the back. The dielectric layer 630 may be selectively shorted to a bus bar and a n-type fingerline doped layer (n +) 621 or a p-type fingerline doped layer (p +) 622 formed through a subsequent process. It serves to block. In addition, the dielectric layer 630 may be formed using a chemical vapor deposition process, a physical vapor deposition process, thermally grown silicon oxide layer, atomic layer deposition (SiO2). , Silicon nitride film (SiNx), aluminum oxide film (Al2O3), silicon carbide film (SiC), or an oxide-based or non-oxide dielectric material, and may be composed of a double or multi-layer structure.

In this state, the n-type fingerline electrode 641 and the p-type fingerline electrically connected to the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622, respectively. An electrode 642 is formed (see FIG. 8D). The n-type fingerline electrode 641 and the p-type fingerline electrode 642 may be formed by two methods.

In the first method, the n-type fingerline doping layer (n +) 621 and the p-type fingerline doping layer (p +) 622 by etching and removing a portion of the dielectric layer 630 while the dielectric layer 630 is stacked. After exposing (see FIG. 8C), a metal material is deposited on the exposed n-type fingerline doping layer (n +) 621 and p-type fingerline doping layer (p +) 622 (see FIG. 8D). It is a method for completing the type finger line electrode 641 and the p-type finger line. In this case, the metal material may be laminated using screen printing or the like.

Meanwhile, in etching and removing a portion of the dielectric layer, only a portion of the fingerline doping layer may be exposed in addition to the method of exposing all of the fingerline doping layers n + and p + as shown in FIG. 8C. In this case, the dielectric layer may be selectively etched so that the exposure pattern having a predetermined shape is repeated. In detail, the dielectric layer may be etched and removed so that unit patterns of circular, square, and oval are repeated to remove the finger line doping layer (n +) ( a portion of p +) may be selectively exposed. Accordingly, the fingerline electrodes 641 and 642 have a structure connected to partially exposed fingerline doping layers n + and p +.

The second method is as follows. Screen printing a conductive paste on the dielectric layer 630 and then firing the metal component in the conductive paste to fire-through the dielectric layer 630 to n-type and p-type fingerline electrodes 641. The n-type fingerline electrode 641 is connected to the n-type fingerline doping layer (n +) 621 while the p-type fingerline electrode 642 is a p-type fingerline doping layer (642). p +) 622 (see FIG. 8D).

With the n-type fingerline electrode 641 and the p-type fingerline electrode 642 formed, the insulating mask 650 is locally applied on the n-type fingerline electrode 641 and the p-type fingerline electrode 642. Laminated.

Specifically, as shown in FIG. 8E, an insulating mask 650 having a predetermined area is formed on the n-type fingerline electrode 641 at a predetermined interval, and the same on the p-type fingerline electrode 642. The insulating mask 650 is formed at regular intervals. At this time, the insulating mask 650 provided to each n-type fingerline electrode 641 and the insulating mask 650 provided to each p-type fingerline electrode 642 have the same horizontal position. Here, the horizontal position refers to a position in a direction perpendicular to the length direction of the n-type or p-type fingerline electrode 642. Hereinafter, the region where the insulating masks 650 are repeatedly arranged and arranged in the horizontal direction is horizontal. This is called an area.

Meanwhile, an area (first horizontal area AAA) including insulating masks 650 provided in the horizontal direction in each of the n-type fingerline electrodes 641 and a horizontal direction in each of the p-type fingerline electrodes 642 are provided. The region (second horizontal region BBB) including the insulating masks 650 have different regions. That is, the first horizontal region and the second horizontal region do not overlap each other. Accordingly, only n-type fingerline electrodes 641 are exposed in the first horizontal area AAA, and only p-type fingerline electrodes 642 are exposed in the second horizontal area BBB.

In this state, as shown in FIG. 8F, the conductive paste is applied on the first horizontal area AAA and the second horizontal area BBB, and then heat-treated to form the n-type busbar in the first horizontal area AAA. An electrode 661 is formed, and a p-type busbar electrode 662 is formed in the second horizontal region BBB. As only the n-type fingerline electrodes 641 are exposed and arranged in the first horizontal area AAA, the n-type busbar electrode 661 is electrically connected to only the n-type fingerline electrodes 641. As only the p-type fingerline electrodes 642 are exposed and repeated in the second horizontal area BBB, the p-type busbar electrode 662 is electrically connected to only the p-type fingerline electrodes 642. To form a connected state. Meanwhile, the width D ₂ of the n-type busbar electrode 661 and the p-type busbar electrode 662 should be smaller than the width of the insulating mask 650. When the width of the busbar electrode is larger than the width D ₁ of the insulating mask 650, different conductive types (<n-type busbar electrode 661 and p-type fingerline electrode 642> or <p-type bus) This is because the bar electrode 662 and the n-type fingerline electrode 641 are short-circuited.

Next, a back electrode solar cell and a method of manufacturing the same according to a fourth embodiment of the present invention will be described in detail.

Referring to FIG. 9, a back electrode solar cell according to a fourth embodiment of the present invention first includes an n-type (or p-type) crystalline silicon substrate 710. A plurality of n-type fingerline doping layers (n +) 721 and a plurality of p-type fingerline doping layers (p +) 722 having a predetermined width and depth are alternately disposed inside the rear surface of the substrate 710. In this case, the n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722 may have the same shape and length, and the n-type fingerline doping layer (n +) ( Each of 721 and p-type fingerline doping layer (p +) 722 is disposed from one end of the substrate 710 to the other end. Meanwhile, a dielectric layer 730 is provided on the back surface of the substrate 710 including the plurality of n-type fingerline doping layers (n +) 721 and the plurality of p-type fingerline doping layers (p +) 722.

The dielectric layer has a first opening 741a and a second opening 742a (see FIG. 10C). The first opening 741a selectively exposes an n-type fingerline doping layer (n +) 721, and the second opening 742a selectively exposes a p-type fingerline doping layer (p +) 722. Expose A plurality of first openings 741a or second openings 742a are provided in one n-type or p-type fingerline doping layer region, where the first openings 741a or the second openings 742a are constant. It is provided at intervals.

The first openings 741a provided in each n-type fingerline doping layer (n +) 721 and the second openings 742a provided in each p-type fingerline doping layer (p +) 722 have the same horizontal position. Has An area where the first openings 741a are repeated and arranged in a horizontal direction is a first horizontal area AAAA, and an area where the second openings 742a are repeated and arranged in a horizontal direction is a second horizontal area BBBB. It will be called.

Meanwhile, an n-type fingerline electrode 741 is provided in the first opening 741a to be connected to an n-type fingerline doping layer (n +) 721 and a p-type fingerline in the second opening 742a. An electrode 742 is provided and connected to the p-type n-type fingerline doping layer p +. Accordingly, only n-type fingerline electrodes 741 are exposed in the first horizontal area AAAA, and only p-type fingerline electrodes 742 are exposed in the second horizontal area BBBB. At this time, the line width of each of the n-type and p-type fingerline electrodes 741 and 742 is equal to the line width of the n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722. It must be the same or smaller than it.

An n-type busbar electrode 751 is provided on the first horizontal area AAAA to be electrically connected to the n-type fingerline electrodes 741 exposed in the first horizontal area, and the second horizontal area BBBB. The p-type busbar electrode 752 is provided to be electrically connected to the exposed p-type fingerline electrodes 742. At this time, the width D ₂ of the n-type busbar electrode 751 and the p-type busbar electrode 752 should be smaller than the length D ₁ of the n-type and p-type fingerline electrodes 741, 742. do.

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 +) ( 721 and a p-type fingerline doping layer (p +) 722. Accordingly, carriers (+) (−) may be collected in all regions of the substrate 710, and cell efficiency may be improved.

In addition, since the n-type and p-type busbar electrodes 751 and 752 are provided on the n-type and p-type fingerline electrodes 741 and 742 without the need for a busbar doping layer, the busbar electrodes It is possible to selectively enlarge the area of the electrode, thereby maximizing the contact area between the busbar electrode and the fingerline electrode, thereby improving the electrical characteristics between the busbar electrode and the fingerline electrode. This busbar electrode is in contact with the structure (see Fig. 2). 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 +) 721 and the p-type fingerline doping layer (p +) 722, thereby allowing the substrate to be reduced. In 710, the collection distance of the carrier collected by the fingerline doping layer (n +) (p +) may be reduced to increase the collection efficiency.

Next, a method of manufacturing a back electrode solar cell according to a fourth embodiment of the present invention will be described. On the other hand, the back electrode solar cell according to the present invention is characterized in the structure of the finger line doping layer, finger line and bus bar provided on the back of the substrate 710, the structure provided on the back of the substrate 710 (fingerline A method of forming the doping layer, the finger line, and the bus bar will be described below, and a detailed description of the structure formed on the entire surface of the substrate 710 will be omitted. Therefore, the manufacturing process for the components required for the back-electrode solar cell in addition to the finger line doping layer, finger line and bus bar can be selectively applied.

First, as shown in FIG. 10A, an n-type or p-type crystalline silicon substrate 710 is prepared. Thereafter, an n-type fingerline doping layer (n +) 721 and a p-type fingerline doping layer (p +) 722 having a predetermined depth are alternately formed on the rear surface of the substrate 710. That is, the plurality of n-type fingerline doping layers (n +) 721 and the plurality of p-type fingerline doping layers (p +) 722 are alternately arranged. In addition, each fingerline doping layer n + (p +) is formed from one end of the substrate 710 to the other end, so that the length of each fingerline doping layer n + (p +) is the length of the substrate 710. Forms the equivalent of Meanwhile, the n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722 may be disposed to be spaced apart from each other or in contact with each other.

The n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722 may be sequentially and independently formed, and may be formed using screen printing, spraying, or ion implantation. have. For example, in the case of using a screen printing method, an n-type impurity layer including n-type impurity ions is formed on a region where an n-type fingerline doping layer (n +) 721 is to be formed, and then n-type impurity is formed through heat treatment. The ions are diffused into the substrate 710 to form the n-type fingerline doped layer (n +) 721, and the p-type fingerline doped layer (p +) 722 may also be formed by the same method.

In the state where the n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722 are alternately arranged on the back surface of the substrate 710, the substrate ( 710 forms a dielectric layer 730 on the backside front surface. The dielectric layer 730 may be selectively shorted to a bus bar and a n-type fingerline doped layer (n +) 721 or a p-type fingerline doped layer (p +) 722 formed through a subsequent process. It serves to block. In addition, the dielectric layer 730 may be formed using a chemical vapor deposition process, a physical vapor deposition process, thermally grown silicon oxide layer, atomic layer deposition (AAAAtomic layer deposition), silicon oxide layer (SiO2) , Silicon nitride film (SiNx), aluminum oxide film (AAAAl2O3), silicon carbide film (SiC), or an oxide-based or non-oxide-based dielectric material and can be composed of a double or multi-layer structure.

In such a state, the dielectric layer 730 is locally etched and removed to selectively select a portion of the n-type fingerline doping layer (n +) 721 and a portion of the p-type fingerline doping layer (p +) 722. Expose

In detail, referring to FIG. 10C, the dielectric layer 730 may be selectively etched and removed to remove the n-type fingerline doping layer (n +) 721 and the p-type fingerline doping layer (p +) 722 at a predetermined interval. First openings 741a and second openings 742a are formed to be exposed. A plurality of first openings 741a are formed along one n-type fingerline doping layer (n +) 721 and a plurality of first openings 741a are formed along one p-type fingerline doping layer (p +) 722. A second opening 742a is formed, an n-type fingerline doping layer (n +) 721 is exposed by the first openings 741a, and a p-type fingerline doping layer () is formed by the second openings 742a. p +) 722 is exposed.

Meanwhile, the first openings 741a provided in each n-type fingerline doping layer (n +) 721 and the second openings 742a provided in each p-type fingerline doping layer (p +) 722 are the same. Has a horizontal position. Here, the horizontal position refers to a position perpendicular to the longitudinal direction of the n-type or p-type fingerline doping layer n + (p +), and the first openings 741a are repeated in the horizontal direction below. The arranged area is called the first horizontal area AAAA and the second openings 742a are repeated in the horizontal direction, and the arranged area is called the second horizontal area BBBB.

The first horizontal area AAAA and the second horizontal area BBBB are alternately arranged. Accordingly, the first openings 741a of the first horizontal region and the second openings 742a of the second horizontal region have different horizontal positions, and the n-type fingerline doping layer in the first horizontal region AAAA. Only the (n +) 721 are exposed, and only the p-type fingerline doping layers (p +) 722 are exposed in the second horizontal region BBBB.

In this state, as illustrated in FIG. 10D, a metal material is stacked in the first opening 741a and the second opening 742a to form the n-type fingerline electrode 741 and the p-type fingerline electrode 742. To form. Accordingly, only the n-type fingerline electrode 741 is provided in the first horizontal area AAAA, and only the p-type fingerline electrode 742 is provided in the second horizontal area BBBB. The metal material may be laminated using screen printing or the like.

Then, as illustrated in FIG. 10E, the conductive paste is applied on the first horizontal area AAAA and the second horizontal area BBBB, and then heat-treated to form the n-type busbar electrode (1) in the first horizontal area AAAA. 751 is formed, and a p-type busbar electrode 752 is formed in the second horizontal region BBBB. As only the n-type fingerline electrodes 741 are exposed and repeatedly arranged in the first horizontal area AAAA, the n-type busbar electrode 751 is electrically connected to only the n-type fingerline electrodes 741. As only the p-type fingerline electrodes 742 are exposed and repeated in the second horizontal region BBBB, the p-type busbar electrode 752 is electrically connected to only the p-type fingerline electrodes 742. To form a connected state. Meanwhile, the width D ₂ of the n-type busbar electrode 751 and the p-type busbar electrode 752 should be smaller than the length D ₁ of the n-type and p-type fingerline electrodes 741, 742. do. When the width D ₂ of the busbar electrode becomes larger than the length D ₁ of the fingerline electrode, different conductive types (<n-type busbar electrode 751 and p-type fingerline electrode 742> or <p) This is because the type busbar electrode 752 and the n type fingerline electrode 741 are short-circuited.

Since a busbar doping layer is not required, a fingerline doping layer may be formed in a region where the busbar doping layer is to be formed, thereby improving carrier collection efficiency.

As the busbar electrode is provided on the fingerline electrode, the area of the busbar electrode can be enlarged without consideration of the busbar doping layer, thereby improving the electrical characteristics between the busbar electrode and the fingerline electrode. . As such, 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.

Claims (38)

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 a portion of the n-type fingerline doping layer (n +); A p-type fingerline electrode formed on a portion of the p-type fingerline doping layer (p +); An n-type busbar electrode provided on the dielectric layer and electrically connected to a plurality of n-type fingerline electrodes; And And a p-type busbar electrode provided on the dielectric layer and electrically connected to the plurality of p-type fingerline electrodes. 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 +); A p-type fingerline electrode formed on 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; An n-type busbar electrode provided on the dielectric layer and electrically connected to a plurality of n-type fingerline electrodes; And And a p-type busbar electrode provided on the dielectric layer and electrically connected to the plurality of p-type fingerline electrodes. 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 and a p-type fingerline electrode formed on the n-type fingerline doping layer (n +) and a p-type fingerline doping layer (p +), respectively; And Comprising a plurality of insulating masks formed on the n-type finger line electrode, p-type finger line electrode spaced apart in the longitudinal direction of the n-type and p-type fingerline, The horizontal area (first horizontal area) including the insulating masks of each n-type fingerline electrode and the horizontal area (second horizontal area) including the insulating masks of each p-type fingerline electrode are different from each other and do not overlap each other. , And an n-type busbar electrode connected to the n-type fingerline electrode on the first horizontal region, and a p-type busbar electrode connected to the p-type fingerline electrode on the second horizontal region. Back-electrode 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 +); And A portion of the dielectric layer is etched to expose a plurality of first openings exposing the n-type fingerline doping layer (n +) and a plurality of second openings exposing the p-type fingerline doping layer (p +); An n-type fingerline electrode provided in the first opening and a p-type fingerline electrode provided in the second opening, Horizontal area (first horizontal area) including first openings of each n-type fingerline doping layer n + and horizontal area (second horizontal area) including second openings of each p-type fingerline doping layer p + ) Are different from each other and do not overlap, And an n-type busbar electrode connected to the n-type fingerline electrode on the first horizontal region, and a p-type busbar electrode connected to the p-type fingerline electrode on the second horizontal region. Back-electrode solar cell. The method according to any one of claims 1 to 4, And the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +), respectively, from one end of the substrate to the other end. The method according to any one of claims 1 to 4, 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 +) Electrode solar cell. The method according to any one of claims 1 to 4, A plurality of n-type finger line doping layer (n +) and a plurality of p-type finger line doping layer (p +), the back electrode type solar cell, characterized in that the alternating arrangement is arranged in contact with each other. The method according to any one of claims 1 to 4, The dielectric layer repeatedly includes a unit pattern exposing a portion of an n-type fingerline doping layer (n +) or a p-type fingerline doping layer (n +), wherein the n-type fingerline electrode and the p-type fingerline electrode are the unit pattern. A back-electrode type solar cell, wherein the back-type solar cell is electrically connected to an n-type fingerline doping layer (n +) or a p-type fingerline doping layer (n +) exposed by a pattern. The method of claim 1, One end of each of the n-type fingerline doping layer n + and the p-type fingerline doping layer p + is a first end and the other end is a second end, The length of each of the n-type fingerline electrode and the p-type fingerline electrode is shorter than that of each of the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), The n-type fingerline electrode is provided at the first end of the n-type fingerline doping layer (n +), and the p-type fingerline electrode is provided at the second end of the p-type fingerline doping layer (p +). Back electrode type solar cell, characterized in that. The method of claim 1, The region where the n-type fingerline electrodes are repeated and arranged (region A), the region where the n-type fingerline electrode and the p-type fingerline electrode are alternately arranged and arranged (region B), and the p-type fingerline electrodes are repeatedly arranged and arranged. Zone (C zone) is provided, An n-type busbar electrode is provided on the substrate backside of the region A, and a p-type busbar electrode is provided on the substrate backside of the region C. The method of claim 2, One end of each of the n-type fingerline electrode and the p-type fingerline electrode is a first end and the other end thereof is a second end, and the insulating mask is formed on the first end of the p-type fingerline electrode and the n-type fingerline electrode. On the second end, And an n-type fingerline electrode or a p-type fingerline electrode adjacent to the insulating mask. The method of claim 11, 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 Area is exposed and is repeated, arranged (area C region), 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. Back electrode type solar cell, characterized in that. The method of claim 2, A width of the n-type busbar electrode and the p-type busbar electrode is smaller than the width of the insulating mask back-side solar cell. The method of claim 3, wherein Only n-type fingerline electrodes are selectively exposed by the insulating mask in the first horizontal area to be connected to an n-type busbar electrode, and only p-type fingerline electrodes are selectively selected by the insulating mask in the second horizontal area. The back electrode solar cell, characterized in that connected to the p-type busbar electrode exposed. The method of claim 3, wherein A width D ₂ of the n-type busbar electrode and the p-type busbar electrode is smaller than the width D ₁ of the insulating mask. The method of claim 4, wherein The width D ₂ of the n-type busbar electrode and the p-type busbar electrode is smaller than the length (D ₁ ) of the n-type fingerline electrode and the p-type fingerline electrode, the back electrode solar cell. Preparing a substrate; Forming a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) alternately disposed inside a rear surface of the substrate; Forming a dielectric layer on the back side of the substrate; Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to a portion of the n-type fingerline doping layer (n +) and a portion of the p-type fingerline doping layer (p +), respectively; And Forming an n-type busbar electrode 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 on the dielectric layer. Method of manufacturing a back-electrode type solar cell. Preparing a substrate; Forming a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) alternately disposed inside a rear surface of the substrate; Forming a dielectric layer on the back side of the substrate; Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +), respectively; Forming an insulating mask on the first end of the p-type fingerline electrode and the second end of the n-type fingerline electrode to expose only the n-type fingerline electrode or the p-type fingerline electrode adjacent to the insulating mask; And A n-type busbar electrode electrically connected to the plurality of n-type fingerline electrodes on the first end, and a p-type busbar electrode electrically connected to the plurality of p-type fingerline electrodes on the second end Method for producing a back-electrode solar cell, characterized in that it comprises a step of forming a. Preparing a substrate; Forming a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) alternately disposed inside a rear surface of the substrate; Forming a dielectric layer on the back side of the substrate; Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +), respectively; And And forming a plurality of insulating masks along the length direction of the n-type and p-type fingerlines on the n-type fingerline electrode and the p-type fingerline electrode. The horizontal area (first horizontal area) including the insulating masks of each n-type fingerline electrode and the horizontal area (second horizontal area) including the insulating masks of each p-type fingerline electrode are different from each other and do not overlap each other. , Forming an n-type busbar electrode connected to the n-type fingerline electrode on the first horizontal region and forming a p-type busbar electrode connected to the p-type fingerline electrode on the second horizontal region. Method of manufacturing a back-electrode solar cell characterized in that it further comprises. Preparing a substrate; Forming a plurality of n-type fingerline doping layers (n +) and a plurality of p-type fingerline doping layers (p +) alternately disposed inside a rear surface of the substrate; Forming a dielectric layer on the back side of the substrate; Selectively etching and removing the dielectric layer to form a plurality of first openings exposing an n-type fingerline doping layer (n +) and a plurality of second openings exposing a p-type fingerline doping layer (p +); Stacking a metal material in the first and second openings to form an n-type fingerline electrode and a p-type fingerline electrode, respectively. Horizontal area (first horizontal area) including first openings of each n-type fingerline doping layer n + and horizontal area (second horizontal area) including second openings of each p-type fingerline doping layer p + ) Are different from each other and do not overlap, Forming an n-type busbar electrode connected to the n-type fingerline electrode on the first horizontal region, and forming a p-type busbar electrode connected to the p-type fingerline electrode on the second horizontal region. Method for producing a back-electrode solar cell comprising a. The method according to any one of claims 17 to 20, The n-type fingerline doping layer (n +) and the p-type fingerline doping layer (p +) each of the manufacturing method of the back-electrode solar cell, characterized in that formed from one end of the substrate to the other end. The method according to any one of claims 17 to 20, The line width of each of the n-type finger line electrode and the p-type finger line electrode is formed to be equal to or smaller than the line width of the n-type finger line doping layer (n +) and the p-type fingerline doping layer (p +). Method of manufacturing a back-electrode type solar cell. The method according to any one of claims 17 to 20, A plurality of n-type finger line doping layer (n +) and a plurality of p-type finger line doping layer (p +), the back electrode type solar cell, characterized in that formed to be alternately arranged in a spaced manner, or in contact with each other. Manufacturing method. The method according to any one of claims 17 to 20, The dielectric layer repeatedly includes a unit pattern exposing a portion of an n-type fingerline doping layer (n +) or a p-type fingerline doping layer (n +), wherein the n-type fingerline electrode and the p-type fingerline electrode are the unit pattern. A method of manufacturing a back-electrode solar cell, characterized in that it is electrically connected to the n-type fingerline doping layer (n +) or p-type fingerline doping layer (n +) exposed by the pattern. The method of claim 17, The region where the n-type fingerline electrodes are repeated and arranged (region A), the region where the n-type fingerline electrode and the p-type fingerline electrode are alternately arranged and arranged (region B), and the p-type fingerline electrodes are repeatedly arranged and arranged. Zone (C zone) is provided, And the n-type busbar electrode is formed on the A region, and the p-type busbar electrode is formed on the C region. The method of claim 17, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to a portion of the n-type fingerline doping layer (n +) and a portion of the p-type fingerline doping layer (p +), respectively, Applying a conductive paste on a dielectric layer corresponding to a portion of the n-type and p-type fingerline doped layers (n +), By firing the conductive paste to form n-type and p-type fingerline electrodes, the metal material of the conductive paste penetrates through the dielectric layer to be electrically connected to the n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a back-electrode solar cell, characterized in that configured to include the process. The method of claim 17, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to a portion of the n-type fingerline doping layer (n +) and a portion of the p-type fingerline doping layer (p +), respectively, Etching and removing a portion of the dielectric layer to expose a portion of the n-type fingerline doping layer n + and a portion of the p-type fingerline doping layer p +; And forming a n-type fingerline electrode and a p-type fingerline electrode by stacking a metal material on the exposed n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a type solar cell. The method of claim 17, One end of each of the n-type fingerline doping layer n + and the p-type fingerline doping layer p + is a first end and the other end is a second end, The length of each of the n-type fingerline electrode and the p-type fingerline electrode is shorter than that of each of the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), The n-type fingerline electrode is formed to be biased in the first end direction of the n-type fingerline doping layer n +, and the p-type fingerline electrode is formed in the second end direction of the p-type fingerline doping layer p +. Method of manufacturing a back-electrode solar cell, characterized in that formed biased. The method of claim 18, 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 Area is exposed and is repeated, arranged (area C region), An n-type busbar electrode connected to the n-type fingerline electrodes is formed on the substrate rear surface of the region A, and a p-type busbar electrode connected to the p-type fingerline electrodes is formed on the substrate rear surface of the region C. Method of manufacturing a back-electrode solar cell, characterized in that. The method of claim 18, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), respectively, Applying a conductive paste on a dielectric layer corresponding to the n-type and p-type fingerline doped layer (n +) (p +) regions; By firing the conductive paste to form n-type and p-type fingerline electrodes, the metal material of the conductive paste penetrates through the dielectric layer to be electrically connected to the n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a back-electrode solar cell, characterized in that configured to include the process. The method of claim 18, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), respectively, Etching and removing a portion of the dielectric layer to expose an n-type fingerline doping layer (n +) and a p-type fingerline doping layer (p +), And forming a n-type fingerline electrode and a p-type fingerline electrode by stacking a metal material on the exposed n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a type solar cell. The method of claim 19, Only n-type fingerline electrodes are selectively exposed by the insulating mask in the first horizontal area to be connected to an n-type busbar electrode, and only p-type fingerline electrodes are selectively selected by the insulating mask in the second horizontal area. Method of manufacturing a back-electrode solar cell, characterized in that connected to the p-type busbar electrode exposed. The method of claim 19, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), respectively, Applying a conductive paste on a dielectric layer corresponding to the n-type and p-type fingerline doped layer (n +) (p +) regions; By firing the conductive paste to form n-type and p-type fingerline electrodes, the metal material of the conductive paste penetrates through the dielectric layer to be electrically connected to the n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a back-electrode solar cell, characterized in that configured to include the process. The method of claim 19, Forming an n-type fingerline electrode and a p-type fingerline electrode electrically connected to the n-type fingerline doping layer (n +) and p-type fingerline doping layer (p +), respectively, Etching and removing a portion of the dielectric layer to expose an n-type fingerline doping layer (n +) and a p-type fingerline doping layer (p +), And forming a n-type fingerline electrode and a p-type fingerline electrode by stacking a metal material on the exposed n-type and p-type fingerline doping layers (n +) (p +). Method of manufacturing a type solar cell. The method of claim 19, The width D ₂ of the n-type busbar electrode and the p-type busbar electrode is smaller than the width (D ₁ ) of the insulating mask manufacturing method of a back-electrode solar cell. The method of claim 20, The width D ₂ of the n-type busbar electrode and the p-type busbar electrode is smaller than the length (D ₁ ) of the n-type and p-type fingerline electrode manufacturing method of a back-electrode solar cell. The method of claim 20, The line width of each of the n-type finger line electrode and the p-type finger line electrode is formed to be equal to or smaller than the line width of the n-type finger line doping layer (n +) and the p-type fingerline doping layer (p +). Method of manufacturing a back-electrode type solar cell. The method of claim 20, A plurality of first openings are formed in one n-type fingerline doping layer (n +) at regular intervals to expose the n-type fingerline doping layer (n +), and one n-type fingerline doping layer (n +) region A plurality of first openings are formed at predetermined intervals in the back electrode type solar cell, characterized in that to expose the n-type finger line doping layer (n +).

Images