KR20110117933A

KR20110117933A - Solar cell module and manufacturing method thereof

Info

Publication number: KR20110117933A
Application number: KR1020100037445A
Authority: KR
Inventors: 김성길
Original assignee: 알티솔라 주식회사
Priority date: 2010-04-22
Filing date: 2010-04-22
Publication date: 2011-10-28

Abstract

It provides a solar cell module. A solar cell module according to an embodiment of the present invention includes a first substrate, a lower electrode positioned on the substrate, a semiconductor layer positioned on the lower electrode, an upper electrode positioned on the semiconductor layer, and a second electrode positioned on the upper electrode. A substrate, wherein the lower electrode and the upper electrode are transparent conductive films, and the upper electrode includes a lower surface facing the semiconductor layer and an upper surface facing the second substrate, wherein the upper surface of the upper electrode is It is adhered to the second substrate.

Description

Solar cell module and manufacturing method thereof

The present invention relates to a solar cell module and a method of manufacturing the same.

Solar cells convert solar energy into electrical energy. Solar cells are basically diodes composed of PN junctions, and are classified into various types according to materials used as light absorption layers.

Solar cells using silicon as a light absorption layer are classified into a wafer type solar cell and a thin film type solar cell.

Thin-film solar cells are thin film or glass substrates. In general, the diffusion distance of carriers is very short compared to crystalline due to the thin film characteristics. Therefore, electron-hole pairs generated by sunlight when manufactured only with PN junction structure Collection efficiency is very low. Therefore, it has a PIN structure in which a light absorption layer made of an intrinsic semiconductor material having high light absorption rate is inserted between a P-type and an N-type semiconductor. The structure of a general thin film solar cell is deposited on a substrate in order of a front transparent conductive film, a PIN film, and a back reflective electrode film.

In particular, the solar cell module for applying to a building integrated photovoltaic (BIPV) system can remove the opaque back reflection electrode film to adjust the light transmittance. However, when the rear reflective electrode film is removed, the light absorbing layer may be removed together, resulting in poor light efficiency.

The problem to be solved by the present invention is to provide a solar cell module and a method of manufacturing the same to maximize the transmittance without loss of light efficiency.

A solar cell module according to an embodiment of the present invention includes a first substrate, a lower electrode positioned on the substrate, a semiconductor layer positioned on the lower electrode, an upper electrode positioned on the semiconductor layer, and a second electrode positioned on the upper electrode. A substrate, wherein the lower electrode and the upper electrode are transparent conductive films, and the upper electrode includes a lower surface facing the semiconductor layer and an upper surface facing the second substrate, wherein the upper surface of the upper electrode is It is adhered to the second substrate.

External light incident through the lower electrode may not be reflected, but may pass through an upper surface of the upper electrode and be transmitted through the front surface of the second substrate.

The second substrate may include transparent glass through which external light passes.

An upper surface of the upper electrode may be attached to the second substrate by an adhesive sheet.

The lower electrode, the semiconductor layer, and the upper electrode, which are sequentially stacked on the substrate, may further include a plurality of pattern units that divide a plurality of unit cells and the plurality of unit cells and electrically connect neighboring unit cells. Can be.

The pattern portion penetrates the lower electrode, fills the first layer with the semiconductor layer, penetrates the semiconductor layer, fills the upper electrode, and passes through the upper electrode and the semiconductor layer. And a third groove filled with the member, and the pattern portion may connect a series of neighboring unit cells in series.

In each of the unit cells, an upper surface of the upper electrode may be continuously formed without bending, and the entire upper surface of the upper electrode may be attached to the second substrate by an adhesive sheet.

According to another aspect of the present invention, there is provided a method of manufacturing a solar cell module, including forming a lower electrode on a first substrate, patterning the lower electrode to form a first groove, and filling the first groove on the lower electrode. Forming a layer, patterning the semiconductor layer to form a second groove, forming an upper electrode filling the second groove over the semiconductor layer, patterning the upper electrode and the semiconductor layer to form a third groove Forming a plurality of unit cells consisting of the substrate, the lower electrode, the semiconductor layer, and the upper electrode, and forming a second substrate on the upper electrode, wherein the upper electrode is the semiconductor layer. A lower surface facing the upper surface and the upper surface facing the second substrate, wherein the upper surface of the upper electrode is the second substrate; Form to bond with.

The forming of the second substrate on the upper electrode may include bonding the upper electrode and the second substrate by an adhesive sheet.

In each of the unit cells, the upper surface of the upper electrode may be continuously formed without bending, and the entire upper surface of the upper electrode may be formed to be bonded to the second substrate by an adhesive sheet.

As described above, according to one embodiment of the present invention, the process of removing the conventional opaque metal layer by laser processing may be omitted by forming both the upper electrode and the lower electrode with a transparent conductive film. Therefore, since the light absorbing layer (semiconductor layer) that generates electricity is not removed, the transmittance can be maximized without losing light efficiency.

1 is a cross-sectional view showing a solar cell module according to an embodiment of the present invention.
2 to 5 are cross-sectional views illustrating a method of manufacturing a solar cell module according to another embodiment of the present invention.
6 is a photograph illustrating a degree of identification of an object using a conventional solar cell module.
7 is a photograph showing the degree to which the object is identified using the solar cell module according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Also, when a layer is referred to as being "on" another layer or substrate, it may be formed directly on another layer or substrate, or a third layer may be interposed therebetween. Portions denoted by like reference numerals denote like elements throughout the specification.

1 is a cross-sectional view showing a solar cell module according to an embodiment of the present invention.

Referring to FIG. 1, in the solar cell module according to the exemplary embodiment of the present invention, the lower electrode 110 is positioned on the first substrate 100. The first substrate 100 may be formed of glass or plastic.

An adhesive sheet 105 is attached between the first substrate 100 and the lower electrode 110. The adhesive sheet 105 may be formed of a polyvinyl butyral (PVB) sheet or a polyethylene vinyl acetate (EVA) sheet. EVA sheet is a copolymer of ethylene and vinyl acetate, and is a vinyl film having excellent transparency, buffering property, elasticity and tensile strength.

The lower electrode 110 may be a transparent conductive film. The lower electrode 110 may be formed of SnO 2, ZnO: Al, ZnO: B, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or the like. The upper surface of the lower electrode 110 may be textured. Texturing refers to forming pyramid structures within 10 μm by etching the surface of the lower electrode 110 for the purpose of reducing light reflection at the surface of the solar cell to increase absorption of effective light into the solar cell.

The semiconductor layer 150 is positioned on the lower electrode 110, and the upper electrode 160 is positioned on the semiconductor layer 150.

For example, the semiconductor layer may be formed by sequentially stacking a P layer having a P-type impurity, an I layer formed of an intrinsic semiconductor, and an N layer having an N-type impurity. The P layer may be formed of any one of boron doped amorphous silicon (Boron doped a-Si: H), amorphous silicon carbide (a-SiC: H) and fine crystalline silicon (mc-Si: H). In addition, the I layer and the N layer may be formed of amorphous silicon (a-Si: H). The P layer, the I layer and the N layer may be deposited by plasma chemical vapor deposition (PECVD).

Unlike the exemplary embodiment of the present invention, the semiconductor layer 150 may be formed by sequentially stacking a P layer having a P-type impurity and an N layer having an N-type impurity without an I layer. In this case, the P layer may be formed of CuInSe 2 (CIS) or CuInGaSe 2 (CIGS), and the N layer may be formed of CdS.

Unlike the conventional case, the upper electrode 160 is formed of a transparent conductive film like the lower electrode 110. The upper electrode 110 may be formed of SnO 2, ZnO: Al, ZnO: B, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or the like.

The second substrate 200 is positioned on the upper electrode 160. An adhesive sheet 180 is attached between the upper electrode 160 and the second substrate 200.

The second substrate 100 may be formed of glass or plastic.

In the solar cell module according to the exemplary embodiment of the present invention, the light incident through the first substrate 100 is absorbed by the semiconductor layer 150, and the remaining light battles the upper electrode 160 formed of the transparent conductive film. The solar cell module exits through the substrate 200.

In the related art, when the upper electrode 160 is formed of an opaque metal material instead of the transparent conductive film, an opening is separately included so that light passes through the upper electrode 160 by laser processing. In the laser processing process, the semiconductor layer 150 is lost and the light efficiency is lowered, and the light diffraction phenomenon is caused by the opening of the upper electrode formed by the laser processing.

However, in the solar cell module according to the exemplary embodiment of the present invention, since the opening for transmitting light to the upper electrode 150 is not formed separately, the transmittance can be maximized while minimizing the decrease in light efficiency.

2 to 5 are cross-sectional views illustrating a method of manufacturing a solar cell module according to another embodiment of the present invention.

Referring to FIG. 2, the lower electrode 110 is formed on the first substrate 100 made of glass or plastic by using a method such as sputtering. The lower electrode 110 is patterned using a laser scribing or mechanical scribing method to form a first groove G1.

Referring to FIG. 3, the semiconductor layer 150 is formed to fill the first groove G1 on the lower electrode 110. Then, the semiconductor layer 150 is patterned by using a laser scribing or mechanical scribing method to form a second groove G2.

Referring to FIG. 4, the upper electrode 160 is formed on the semiconductor layer 150 to fill the second groove G2. In addition, the third electrode G3 is formed by patterning the upper electrode 160 and the semiconductor layer 150 using a laser scribing or mechanical scribing method.

When the third groove G3 is formed, the solar cell module is divided into a plurality of unit cells UC1, UC2, UC3,.

Specifically, the pattern portion structure includes a first pattern region in which the first groove G1 is located, a second pattern region in which the second groove G2 is located, and a third pattern region in which the third groove G3 is located. Therefore, neighboring unit cells may be connected in series.

The first groove G1 serves to insulate the lower electrode 110, and the second groove G2 electrically connects the upper electrode and the lower electrode. In addition, the third groove G3 insulates neighboring unit cells from each other in a solar cell having a plurality of unit cells UC1, UC2, and UC3.

Referring to FIG. 5, the second substrate 200 made of glass or plastic is attached onto the upper electrode 160 using the adhesive sheet 180. In FIG. 5, when the portion labeled “A” is enlarged, the portion appears as shown in FIG. 1. That is, FIG. 1 may show a unit cell structure of a solar cell module according to an embodiment of the present invention.

6 is a photograph illustrating a degree of identification of an object using a conventional solar cell module. 7 is a photograph showing the degree to which the object is identified using the solar cell module according to an embodiment of the present invention.

In the conventional solar cell module, external light is transmitted through the opening of the upper electrode formed by laser processing to enter the room. Referring to FIG. 6, in identification of an object through an opening in a conventional solar cell module, the object is blurred according to a near focus and a background focus (diffraction grating phenomenon of light), and thus it is difficult to identify the object.

However, referring to FIG. 7, in the case of the solar cell module according to the exemplary embodiment of the present invention, it can be seen that the objects appearing according to the near focus and the background focus are more clear and thus the objects are easily identified.

This is because the solar cell module according to the embodiment of the present invention uses a transparent conductive film as the upper electrode, thereby reducing distortion of the object due to focus when visually confirmed due to the refraction and scattering of light according to the laser processing width. .

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

100, 200 1st board | substrate, 2nd board | substrate 105, 180 adhesive sheet
110 Lower electrode 120 P layer
130 I floor 140 N floor
150 semiconductor layer 160 upper electrode
G1, G2, G3 First to Third Grooves
UC1, UC2, UC3 First to Third Unit Cells

Claims

First substrate,
A lower electrode on the substrate,
A semiconductor layer on the lower electrode,
An upper electrode on the semiconductor layer;
A second substrate positioned on the upper electrode;
The lower electrode and the upper electrode is a transparent conductive film,
And the upper electrode includes a lower surface facing the semiconductor layer and an upper surface facing the second substrate, and an upper surface of the upper electrode is adhered to the second substrate.

In claim 1,
The external light incident through the lower electrode is not reflected, but passes through the upper surface of the upper electrode and is transmitted through the front surface of the second substrate.

In claim 2,
The second substrate is a solar cell module comprising a transparent glass through which external light passes.

In claim 1,
An upper surface of the upper electrode is bonded to the second substrate by an adhesive sheet.

In claim 1,
The lower electrode, the semiconductor layer, and the upper electrode stacked on the substrate in turn may include a plurality of unit cells;
And a plurality of pattern parts that divide the plurality of unit cells and electrically connect neighboring unit cells to each other.

In claim 5,
The pattern portion
A first groove penetrating the lower electrode and filled with the semiconductor layer,
A second groove penetrating the semiconductor layer and filled with the upper electrode;
And a third groove penetrating the upper electrode and the semiconductor layer and filled with the conductive member, wherein the pattern portion connects the unit cells adjacent to each other in series.

In claim 6,
The upper surface of the upper electrode in each of the unit cells is continuously formed without bending, the entire upper surface of the upper electrode is bonded to the second substrate by an adhesive sheet.

Forming a lower electrode on the first substrate,
Patterning the lower electrode to form a first groove,
Forming a semiconductor layer filling the first groove on the lower electrode;
Patterning the semiconductor layer to form a second groove;
Forming an upper electrode on the semiconductor layer, the upper electrode filling the second groove;
Forming a plurality of unit cells including the substrate, the lower electrode, the semiconductor layer, and the upper electrode by patterning the upper electrode and the semiconductor layer to form a third groove;
Forming a second substrate on the upper electrode;
And the upper electrode includes a lower surface facing the semiconductor layer and an upper surface facing the second substrate, and the upper surface of the upper electrode is formed to adhere to the second substrate.

9. The method of claim 8,
The forming of the second substrate on the upper electrode includes bonding the upper electrode and the second substrate by an adhesive sheet.

9. The method of claim 8,
The upper surface of the upper electrode in each of the unit cells is continuously formed without bending, and the entire upper surface of the upper electrode is formed to be bonded to the second substrate by an adhesive sheet.