KR101449097B1

KR101449097B1 - Solar cell

Info

Publication number: KR101449097B1
Application number: KR1020120035665A
Authority: KR
Inventors: 배도원; 박덕훈
Original assignee: 엘지이노텍 주식회사
Priority date: 2012-04-05
Filing date: 2012-04-05
Publication date: 2014-10-10
Also published as: KR20130113238A

Abstract

A solar cell according to an embodiment includes a substrate; A rear electrode layer disposed on the substrate; A light absorbing layer disposed on the rear electrode layer; A front electrode layer disposed on the light absorbing layer; And an anti-reflection layer disposed between the substrate and the rear electrode layer.
A solar cell according to another embodiment includes: a substrate; A rear electrode layer disposed on the substrate; A light absorbing layer disposed on the rear electrode layer; A front electrode layer disposed on the light absorbing layer; And a heat insulating layer disposed between the substrate and the rear electrode layer.

Description

Solar cell {SOLAR CELL}

An embodiment relates to a solar cell.

A manufacturing method of a solar cell for solar power generation is as follows. First, a substrate is provided, a back electrode layer is formed on the substrate, and the back electrode layer is patterned by a laser to form a plurality of back surface electrodes.

Then, a light absorption layer, a buffer layer, and a high-resistance buffer layer are sequentially formed on the back electrodes. A method of forming a light absorbing layer of copper-indium-gallium-selenide (Cu (In, Ga) Se 2; CIGS system) while simultaneously or separately evaporating copper, indium, gallium and selenium in order to form the above- A method in which a metal precursor film is formed and then formed by a selenization process is widely used. The band gap of the light absorption layer is about 1 to 1.8 eV.

Thereafter, a buffer layer containing cadmium sulfide (CdS) is formed on the light absorption layer by a sputtering process. The energy band gap of the buffer layer is about 2.2 to 2.4 eV. Then, a high resistance buffer layer containing zinc oxide (ZnO) is formed on the buffer layer by a sputtering process. The energy band gap of the high resistance buffer layer is about 3.1 to 3.3 eV.

Then, a groove pattern may be formed in the light absorption layer, the buffer layer, and the high resistance buffer layer.

Thereafter, a transparent conductive material is laminated on the high-resistance buffer layer, and the transparent conductive material is filled in the groove pattern. Accordingly, a transparent electrode layer is formed on the high-resistance buffer layer, and connection wirings are formed inside the groove pattern, respectively. Examples of the material used for the transparent electrode layer and the connection wiring include aluminum-doped zinc oxide and the like. The energy band gap of the transparent electrode layer is about 3.1 to 3.3 eV.

Thereafter, a groove pattern is formed on the transparent electrode layer and the like to form a plurality of solar cells. The transparent electrodes and the high-resistance buffers correspond to respective cells. The transparent electrodes and the high resistance buffers may be arranged in a stripe form or a matrix form.

The transparent electrodes and the back electrodes are mutually misaligned, and the transparent electrodes and the back electrodes are electrically connected to each other by the connection wirings. Accordingly, a plurality of solar cells can be electrically connected to each other in series.

Thus, various types of photovoltaic devices can be manufactured and used to convert sunlight into electrical energy. Such a photovoltaic power generation apparatus is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-2008-0088744.

When such a solar cell is applied to a building, there is a phenomenon that the visual field is disturbed by the reflection of the rear electrode layer. In addition, there is a problem that the heat generated in the building is transmitted to the solar cell inversely, thereby deteriorating power generation performance.

The embodiment can provide a solar cell with improved reliability.

A solar cell according to an embodiment includes a substrate; A rear electrode layer disposed on the substrate; A light absorbing layer disposed on the rear electrode layer; A front electrode layer disposed on the light absorbing layer; And an anti-reflection layer disposed between the substrate and the rear electrode layer.

A solar cell according to another embodiment includes: a substrate; A rear electrode layer disposed on the substrate; A light absorbing layer disposed on the rear electrode layer; A front electrode layer disposed on the light absorbing layer; And a heat insulating layer disposed between the substrate and the rear electrode layer.

A solar cell according to an embodiment includes an antireflection layer disposed between a substrate and a rear electrode layer, and can prevent an image reflection due to the rear electrode layer through the antireflection layer. Therefore, when the solar cell according to the embodiment is applied to a building or the like, visibility can be improved without obstructing the visual field due to reflection. The antireflection layer may further include a pigment to realize various colors.

Meanwhile, the solar cell according to another embodiment includes a heat insulating layer disposed between the substrate and the rear electrode layer, and can block heat transmitted to the interior of the solar cell through the heat insulating layer. Therefore, even if the heat generated in the building is transmitted to the solar cell inversely, it can be blocked thereby preventing the power generation performance from deteriorating.

FIG. 1 is a cross-sectional view showing one end surface of a solar cell according to an embodiment.

In the description of the embodiments, it is to be understood that each layer (film), area, pattern or structure may be referred to as being "on" or "under / under" Quot; includes all that is formed directly or through another layer. The criteria for top / bottom or bottom / bottom of each layer are described with reference to the drawings.

The thickness or the size of each layer (film), region, pattern or structure in the drawings may be modified for clarity and convenience of explanation, and thus does not entirely reflect the actual size.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, a solar cell according to an embodiment will be described in detail with reference to FIG. FIG. 1 is a cross-sectional view showing one end surface of a solar cell according to an embodiment.

1, a solar cell according to an embodiment includes a support substrate 100, an antireflection layer 700, a back electrode layer 200, a light absorption layer 300, a buffer layer 400, a high resistance buffer layer 500, And an electrode layer (600).

The supporting substrate 100 has a plate shape and supports the rear electrode layer 200, the light absorbing layer 300, the buffer layer 400, and the front electrode layer 600.

The support substrate 100 may be an insulator. The support substrate 100 may be a glass substrate, a plastic substrate, or a metal substrate. More specifically, the support substrate 100 may be a soda lime glass substrate. The support substrate 100 may be transparent

The antireflection layer 700 is disposed on the upper surface of the supporting substrate 100. The antireflection layer 700 is disposed between the supporting substrate 100 and the rear electrode layer 200. The anti-reflection layer 700 may be disposed on the front surface of the supporting substrate 100.

The anti-reflection layer 700 includes a ceramic paint. For example, the antireflection layer 700 may include an oxide. To be specific, the anti-reflection layer 700 is zinc oxide (ZnO), titanium dioxide (TiO _2), zinc sulfide (ZnS), barium sulfate (BaSO ₄₎ or basic lead carbonate _{(2PbCO 3 · Pb (OH)} 2) .

It is possible to prevent image reflection by the rear electrode layer 200 through the antireflection layer 700. Therefore, when the solar cell according to the embodiment is applied to a building or the like, visibility can be improved without obstructing the visual field due to reflection.

The anti-reflection layer 700 may further include a pigment. Through this, various colors can be realized. The pigment may comprise lead chromate (PbCrO ₄ ), iron oxide (FeO (OH)) or lead oxide (PbO). Also, the pigment may include chrome orange ROM _{(PbCrO 4 · (PbO))} .

The rear electrode layer 200 is disposed on the upper surface of the antireflection layer 700. The rear electrode layer 200 is a conductive layer. Examples of the material used for the rear electrode layer 200 include metals such as molybdenum (Mo).

In addition, the rear electrode layer 200 may include two or more layers. At this time, the respective layers may be formed of the same metal or may be formed of different metals.

The light absorption layer 300 is disposed on the rear electrode layer 200. The light absorption layer 300 includes an I-III-VI group compound. For example, the light absorption layer 300 may be formed of a copper-indium-gallium-selenide (Cu (In, Ga) Se 2; CIGS) crystal structure, a copper- Crystal structure.

The energy band gap of the light absorption layer 300 may be about 1 eV to 1.8 eV.

The buffer layer 400 is disposed on the light absorption layer 300. The buffer layer 400 is in direct contact with the light absorption layer 300.

The buffer layer 400 may include a sulfide. For example, the buffer layer 400 may include cadmium sulfide.

The high resistance buffer layer 500 is disposed on the buffer layer 400. The high-resistance buffer layer 500 includes zinc oxide (i-ZnO) that is not doped with impurities. The energy band gap of the high resistance buffer layer 500 may be about 3.1 eV to 3.3 eV.

The front electrode layer 600 is disposed on the light absorption layer 300. More specifically, the front electrode layer 600 is disposed on the high-resistance buffer layer 500.

The front electrode layer 600 is transparent. Examples of the material used for the front electrode layer 600 include Al-doped ZnO (AZO), indium zinc oxide (IZO), indium tin oxide (ITO), and the like. .

The thickness of the front electrode layer 600 may be about 500 nm to about 1.5 占 퐉. In addition, when the front electrode layer 600 is formed of zinc oxide doped with aluminum, aluminum may be doped at a ratio of about 1.5 wt% to about 3.5 wt%. The front electrode layer 600 is a conductive layer.

Hereinafter, a solar cell according to another embodiment will be described. For the sake of clarity and conciseness, the same or similar parts as those described above will not be described in detail.

A solar cell according to another embodiment includes a support substrate, a heat insulating layer, a rear electrode layer, a light absorbing layer, a buffer layer, a high resistance buffer layer, and a front electrode layer.

And the heat insulating layer is disposed between the supporting substrate and the rear electrode layer.

The heat insulating layer includes a ceramic paint. The thermal conductivity of the ceramic paint is lower than that of molybdenum (Mo) contained in the rear electrode layer, thereby blocking heat transmitted to the inside of the solar cell. Therefore, even if the heat generated in the building is transmitted to the solar cell inversely, it can be blocked thereby preventing the power generation performance from deteriorating.

In one example, the insulating layer may comprise an oxide. Specifically, the heat insulating layer can include a zinc oxide (ZnO), titanium dioxide (TiO _2), zinc sulfide (ZnS), barium sulfate (BaSO ₄₎ or basic lead carbonate _{(2PbCO 3 · Pb (OH)} 2) .

The heat insulating layer may further include a pigment. Through this, various colors can be realized. The pigment may comprise lead chromate (PbCrO ₄ ), iron oxide (FeO (OH)) or lead oxide (PbO). Also, the pigment may include chrome orange _{(PbCrO 4 · (PbO))} .

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

Claims

Board;
A rear electrode layer disposed on the substrate;
A light absorbing layer disposed on the rear electrode layer;
A front electrode layer disposed on the light absorbing layer; And
And an antireflection layer disposed between the substrate and the rear electrode layer,
Wherein the antireflection layer comprises a ceramic paint.

Board;
A rear electrode layer disposed on the substrate;
A light absorbing layer disposed on the rear electrode layer;
A front electrode layer disposed on the light absorbing layer; And
And an antireflection layer disposed between the substrate and the rear electrode layer,
Wherein the antireflection layer comprises a pigment.

The method according to claim 1,
Wherein the antireflection layer comprises an oxide.

The method according to claim 1,
The anti-reflection layer is a material selected from the group consisting of zinc oxide (ZnO), titanium dioxide (TiO _2), zinc sulfide (ZnS), barium sulfate (BaSO ₄₎ and basic lead carbonate _{(2PbCO 3 · Pb (OH)} 2) Building-integrated solar cell containing one.

The method according to claim 1,
Wherein the antireflection layer further comprises a pigment.

6. The method of claim 5,
The pigment is lead chromate (PbCrO _4), iron oxide (FeO (OH)) and lead oxide (PbO) building integrated solar cell comprising any of the materials selected from the group consisting of.

The method according to claim 1,
Wherein the antireflection layer is disposed on a front surface of the substrate.

Board;
A rear electrode layer disposed on the substrate;
A light absorbing layer disposed on the rear electrode layer;
A front electrode layer disposed on the light absorbing layer; And
And a heat insulating layer disposed between the substrate and the rear electrode layer,
Wherein the heat insulating layer comprises a ceramic paint.

delete

9. The method of claim 8,
The heat insulating layer is either a material selected from the group consisting of zinc oxide (ZnO), titanium dioxide (TiO _2), zinc sulfide (ZnS), barium sulfate (BaSO ₄₎ and basic lead carbonate _{(2PbCO 3 · Pb (OH)} 2) One integrated solar cell containing one.

9. The method of claim 8,
Wherein the heat insulating layer further comprises a pigment.

12. The method of claim 11,
The pigment is lead chromate (PbCrO _4), iron oxide (FeO (OH)) and lead oxide (PbO) building integrated solar cell comprising any of the materials selected from the group consisting of.