KR101212489B1 - Method for manufacturing solar cell - Google Patents

Abstract

A method of manufacturing a solar cell includes preparing a screen mask for a solar cell and performing metal printing based on the screen mask. The screen mask includes at least one auxiliary finger line opening formed at an edge of the screen mask and intersecting with at least a portion of the at least one finger line opening.

Description

Solar cell manufacturing method {METHOD FOR MANUFACTURING SOLAR CELL}

The disclosed technology relates to a method of manufacturing a solar cell, and more particularly, to a method of manufacturing a solar cell having an improved electrode structure of a solar cell.

A solar cell refers to a cell that converts light into electricity using sunlight. An electron and a hole charge are generated by light by joining a p-type semiconductor where conduction is caused by holes and an n-type semiconductor where conduction is caused by electrons. The photovoltaic cell uses the principle of generating photovoltaic power as the current flows.

Among the embodiments, the method of manufacturing a solar cell includes preparing a screen mask for a solar cell and performing metal printing based on the screen mask. The screen mask includes at least one auxiliary finger line opening formed at an edge of the screen mask and intersecting with at least a portion of the at least one finger line opening.

In one embodiment, at least a portion of the at least one auxiliary finger line may intersect with all of the at least one finger line. In one embodiment, the method of manufacturing the solar cell may further include a firing process of performing rapid heat treatment after the metal printing.

1 illustrates a solar cell according to an embodiment of the disclosed technology.
2 and 3 are views for explaining a first manufacturing process for manufacturing the solar cell of FIG.
4 and 5 are diagrams for describing a second manufacturing process of manufacturing the solar cell of FIG. 1.
6 and 7 are views for explaining a third manufacturing process for manufacturing the solar cell of FIG.

Description of the present application is only an embodiment for structural or functional description, the scope of the disclosed technology should not be construed as limited by the embodiments described in the text. That is, the embodiments may be variously modified and may have various forms, and thus, the scope of the disclosed technology should be understood to include equivalents capable of realizing the technical idea.

Meanwhile, the meaning of the terms described in the present application should be understood as follows.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be named a second component, and similarly, the second component may also be named a first component.

When a component is referred to as being "connected" to another component, it should be understood that there may be other components in between, although it may be directly connected to the other component. On the other hand, when a component is said to be "directly connected" to another component, it should be understood that the other component does not exist. On the other hand, other expressions describing the relationship between the components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring", should be interpreted as well.

It should be understood that the singular " include "or" have "are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed technology belongs. Generally, the terms defined in the dictionary used are to be interpreted as being consistent with the meaning in the context of the related art, and should not be interpreted as having ideal or excessively formal meanings unless clearly defined in the present application.

1 illustrates a solar cell according to an embodiment of the disclosed technology.

Referring to FIG. 1, the solar cell 100 includes a solar cell structure 110, a bus bar 120, a finger line 130, and an auxiliary finger line 140.

The solar cell structure 110 may be stacked with p-type and n-type semiconductor substrates. In one embodiment, the solar cell structure 110 may deposit an n-type semiconductor layer through a diffusion process on a p-type silicon wafer. In another embodiment, the solar cell structure 110 may stack n-type and p-type semiconductor layers on a glass substrate.

The busbar 120 may be formed on the solar cell structure 110, and in one embodiment, may be composed of Ni, Ag, Cu, or a combination thereof. In one embodiment, the busbar 120 may be implemented with at least one. In one embodiment, if the busbars 120 are implemented in plural, the plurality of busbars 120 may be implemented in parallel and spaced apart.

Finger line 130 may be formed on solar cell structure 110 and, in one embodiment, may be comprised of Ni, Ag, Cu, or a combination thereof. The finger line 130 may collect carriers generated in the solar cell structure 110 and move them to the bus bar 120, and may vertically intersect with the bus bar 120. In one embodiment, the finger line 130 may be implemented in at least one. In one embodiment, if the finger lines 130 are implemented in plural, the plurality of finger lines 130 may be implemented in parallel with each other.

The auxiliary finger line 140 may be formed on the solar cell structure 110, and in one embodiment, may be composed of Ni, Ag, Cu, or a combination thereof. Auxiliary finger line 140 is to increase the collection of carriers in the corner portion of the solar cell structure 110, may be formed in the corner of the solar cell structure 110 and intersect at least a portion of the finger line 130. have. In one embodiment, the auxiliary finger line 140 may be parallel to the busbar 120 and intersect with all of the finger lines 130. In one embodiment, at least some of the auxiliary finger lines 140 may not intersect with the at least one busbar 120. In one embodiment, the auxiliary finger line 140 may be implemented in the same number at both ends of the corner. For example, when the number of the auxiliary finger lines 140 corresponds to four, two auxiliary finger lines 140 may be disposed at both ends of each corner.

2 and 3 are views for explaining a first manufacturing process for manufacturing the solar cell of FIG.

In FIG. 2, the solar cell 200 may form an electrode by a metal printing technique. In one embodiment, the metal printing technique may use a screen mask, the screen mask having an opening corresponding to the electrode structure in FIG. 1, and in one embodiment, may be made of silk or stainless steel mesh and An emulsion may be used to form the electrode structure.

In FIG. 3, the first conductive semiconductor substrate 210 is prepared for manufacturing the solar cell 200 (step S310). In one embodiment, the first conductivity type semiconductor substrate 210 may correspond to a p-type semiconductor wafer.

Texturing (ie, surface organization) is performed on the first conductivity-type semiconductor substrate 210, and in one embodiment, the first conductivity-type semiconductor substrate 210 may have the shape of a pyramid structure (step S320). ).

The second conductive semiconductor layer 220 is doped onto the first conductive semiconductor substrate 210, and in one embodiment, the second conductive semiconductor layer 220 may correspond to an n-type semiconductor. POCl ₃ , H ₃ PO ₄ and the like may be formed through a process of diffusing at high temperature (step S330).

A solar cell screen mask is disposed on the solar cell structure 260. In one embodiment, the screen mask may form an opening corresponding to the electrode structure in FIG. 1 (step S340).

A metal printing process may be performed on the solar cell structure 260 to form a metal pattern corresponding to the electrode structure of FIG. 1 on the surface of the solar cell structure 260 (step S350).

The metal formed on the solar cell structure 260 may be rapidly heat-treated in a high temperature belt type kiln to chemically contact the second conductive semiconductor layer 220 (step S360).

2 and 3, the screen mask may have an inverse pattern of the electrode structure of the solar cell in FIG. 1. That is, in the case of the electrode structure of the solar cell, the lines in FIG. 1 (ie, the busbars, the finger lines, and the auxiliary finger lines) describe the actual shape, but in the case of the screen mask, the lines in FIG. 1 are empty. Replaced by space.

4 and 5 are diagrams for describing a second manufacturing process of manufacturing the solar cell of FIG. 1.

In FIG. 4, an electrode of the solar cell 400 may be recessed by forming a groove corresponding to the electrode structure illustrated in FIG. 1 in the solar cell structure 470. In one embodiment, a groove is formed on a surface of the solar cell 400 in a predetermined electrode pattern, and the predetermined electrode pattern corresponds to the bus structure 440 and the finger line 450 corresponding to the electrode structure shown in FIG. 1. And an auxiliary finger line 460 pattern portion.

In FIG. 5, for manufacturing the solar cell 400, a first conductivity type semiconductor substrate 410 is prepared (step S510). In one embodiment, the first conductivity type semiconductor substrate 410 may correspond to a p-type semiconductor wafer.

Texturing (ie, surface texture) is performed on the first conductive semiconductor substrate 410, and in one embodiment, the first conductive semiconductor substrate 410 may have a pyramidal shape (step S520). ).

The second conductivity type semiconductor layer 420 is doped on the first conductivity type semiconductor substrate 410, and in one embodiment, the second conductivity type semiconductor layer 420 may correspond to an n type semiconductor. POCl ₃ , H ₃ PO ₄ and the like may be formed through a process of diffusing at high temperature (step S530).

The oxide film 430 and the anti-reflection film 435 are deposited on the second conductive semiconductor layer 420 in order. In one embodiment, the oxide film 430 may be formed of SiO ₂ and the thickness may correspond to 10 nm. Can be. The oxide film 430 may be grown by injecting oxygen at a high temperature, and the anti-reflection film 435 may be formed using a CVD (chemical vapor deposition) method (step S540).

Grooves are formed on the surface of the solar cell structure 470 by a predetermined electrode pattern, and in one embodiment, the grooves may be formed using a photo pattern forming technique using a photosensitive layer, a laser or a diamond blade (step S550). .

Impurities may be removed through an etching process on the groove formed in the predetermined electrode pattern (step S560).

The groove region formed by the predetermined electrode pattern may be doped with a higher concentration of the second conductivity type semiconductor to reduce the contact resistance of the electrode, and in one embodiment, the second conductivity type semiconductor may correspond to the n type semiconductor ( Step S570).

An electrode is formed in the groove region formed with a predetermined electrode pattern, and in one embodiment, the electrode may be formed using electroless plating or vacuum deposition (step S580).

6 and 7 are views for explaining a third manufacturing process for manufacturing the solar cell of FIG.

In FIG. 6, the surface of the solar cell 600 may be formed in an inverted pyramid structure. In one embodiment, the electrode of the solar cell 600 may be formed using a metal printing technique on the surface of the inverted pyramid structure, the high concentration of the first electrode in contact with the second conductive semiconductor layer 620 2 conductivity type semiconductor is doped to reduce the contact resistance.

In FIG. 7, for manufacturing the solar cell 600, the first conductivity type semiconductor substrate 610 is prepared (step S710). In one embodiment, the first conductivity type semiconductor substrate 610 may correspond to a p-type semiconductor wafer.

Texturing (ie, surface texture) is performed on the first conductive semiconductor substrate 610, and in one embodiment, the first conductive semiconductor substrate 610 may have an inverted pyramid structure through an etching process. (Step S720).

The second conductive semiconductor layer 620 is doped on the first conductive semiconductor substrate 610 (step S730), and in one embodiment, a process of diffusing POCl ₃ , H ₃ PO _4, and the like at high temperature It can be formed through. For example, the second conductivity type semiconductor layer 620 may correspond to an n type semiconductor.

The oxide layer 630 may be deposited on the front and rear surfaces of the solar cell structure 670 (step S740), thereby reducing the recombination of carriers to increase the photoelectric conversion efficiency of the solar cell 600. In one embodiment, the oxide layer 630 may be configured to have a thickness of 200 μm, but is not limited thereto. The thickness provides a suitable efficiency of the photoelectric conversion efficiency by the oxide layer 630, and when thinner or thicker, the thickness may pose a problem of photoelectric conversion efficiency and / or economy.

A solar cell screen mask is disposed on the solar cell structure 670. In one embodiment, the screen mask may form an opening corresponding to the electrode structure in FIG. 1 (step S750).

A metal printing process may be performed on the solar cell structure 670 to form a metal pattern corresponding to the electrode structure of FIG. 1 on the surface of the solar cell structure 670 (step S760).

The metal formed in the solar cell structure 670 may be rapidly heat-treated in a high temperature belt type kiln to be in chemical contact with the second conductive semiconductor layer 620 (step S770).

In FIGS. 6 and 7, the screen mask is substantially the same as the screen mask described with reference to FIGS. 2 and 3, and thus description thereof will be omitted.

The disclosed technique may have the following effects. However, since a specific embodiment does not mean to include all of the following effects or only the following effects, it should not be understood that the scope of the disclosed technology is limited by this.

The solar cell according to the exemplary embodiment may increase the collection amount of carriers by forming an auxiliary finger line intersecting at least a portion of the finger line on the edge portion of the solar cell structure.

The solar cell according to an embodiment may form an effective electrode structure as the light receiving area of the solar cell increases by using an auxiliary finger line. For example, even if the size of a recent solar cell is designed to be 6 inches or more, solar cells can efficiently collect carriers.

Although described above with reference to the preferred embodiment of the present application, those skilled in the art various modifications and changes to the present application without departing from the spirit and scope of the present application described in the claims below I can understand that you can.

100: solar cell
110, 260, 470, 670: solar cell structure
120, 230, 440, 640: bus bar
130, 240, 450, 650: finger line
140, 250, 460, 660: secondary finger lines
210: p-type semiconductor substrate
220: n-type semiconductor layer
430 oxide film
435: antireflection film
630: oxide layer

Claims (3)

Preparing a screen mask for a solar cell; And
Performing metal printing based on the screen mask,
And the screen mask comprises at least one auxiliary finger line opening formed at an edge of the screen mask and intersecting with at least a portion of the at least one finger line opening.
The method of claim 1, wherein at least a portion of the at least one auxiliary finger line is
And one finger line intersects the finger line, and two or more finger lines intersect all of the finger lines.

The method of claim 1,
After the metal printing, the method of manufacturing a solar cell further comprising a rapid heat treatment process.

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