KR20130072647A - See through type solar cell and fabricating method - Google Patents

Abstract

PURPOSE: A see through type solar cell module and a manufacturing method thereof are provided to increase power by using a mesh type back electrode layer. CONSTITUTION: A back electrode layer (200) is arranged on a support substrate. A p-type semiconductor layer (300) is arranged on the back electrode layer. An n-type semiconductor layer (500) is arranged in the p-type semiconductor layer. The back electrode layer includes an opening part. The back electrode layer includes a first and a second back contact electrode part.

Description

See-through solar cell module and its manufacturing method {SEE THROUGH TYPE SOLAR CELL AND FABRICATING METHOD}

An embodiment relates to a see-through solar cell module and a method of manufacturing the same.

A solar cell can be defined as a device that converts light energy into electric energy by using a photovoltaic effect that generates electrons when light is applied to a p-n junction diode. The solar cell can be classified into a silicon solar cell, a compound semiconductor solar cell represented by group I-III-VI or III-V, a dye-sensitized solar cell, and an organic solar cell, depending on materials used as a junction diode.

CIGS (CuInGaSe) solar cell, which is one of the I-III-VI family chalcopyrite compound semiconductors, has excellent light absorption, high photoelectric conversion efficiency even at a thin thickness, and excellent electro- It is emerging as an alternative solar cell. In general, CIGS thin film solar cells are manufactured by sequentially forming a substrate containing a sodium, a back electrode layer, a p-type semiconductor layer, a buffer layer and a front electrode layer.

The minimum unit of a solar cell is called a cell, and the voltage from one solar cell is usually very small, about 0.5 V to about 0.6 V. Therefore, a plurality of solar cells are connected in series on a substrate to produce a panel to obtain a voltage from several V to several hundred V or more, which is called a solar cell module.

In the related art, since the side surfaces of the cells are closely contacted with each other as a method for improving the power generation efficiency of the solar cell module, there is a problem that light cannot pass through and thus is not suitable for use as a building exterior material.

In order to solve this problem, by using a transparent back sheet and widening the interval between the solar cells to allow the external light to pass through, the solar cell module is used as the exterior material of the building, the power generation used in the building In order to obtain a see-through type solar cell that can be used as a solar cell has been disclosed.

However, in the case of the conventional see-through solar cell module, the light emitting part is formed by removing all of the rear electrode layer, the p-type semiconductor layer, and the front electrode layer, or by connecting the light emitting part with a predetermined distance to the cell by mosaic connecting the light emitting part to the actual output. It does not help at all, and the output is reduced by the ratio of light emitters.

Embodiments provide a see-through solar cell module and a manufacturing method thereof for forming a light transmitting part without power loss.

The see-through solar cell module according to the embodiment includes a plurality of solar cells. Each of the solar cells may include a rear electrode layer disposed on a support substrate and including an opening; A p-type semiconductor layer disposed on the back electrode layer; A buffer layer disposed on the p-type semiconductor layer; And an n-type semiconductor layer disposed on the buffer layer.

According to an embodiment, there is provided a method of manufacturing a see-through solar cell module, including forming a back electrode layer including an opening on a support substrate; Forming a p-type semiconductor layer on the back electrode layer; Forming a buffer layer on the p-type semiconductor layer; And forming an n-type semiconductor layer on the buffer layer.

The see-through solar cell module according to the embodiment includes a back electrode layer having a mesh shape. The back electrode layer having a mesh shape may function as a light transmitting part, and thus, the embodiment may provide a high output see-through solar cell module without power loss.

1 is a cross-sectional view showing a cross-sectional view of a see-through solar cell module according to the embodiment.
2 to 5 are plan views of a rear electrode layer including an opening according to an embodiment.
6 is a cross-sectional view illustrating the sunlight passing through the see-through solar cell module according to the embodiment.

In the description of the embodiments, where each substrate, layer, film, or electrode is described as being formed "on" or "under" of each substrate, layer, film, or electrode, etc. , “On” and “under” include both “directly” or “indirectly” other components. In addition, the upper or lower reference of each component is described with reference to the drawings. The size of each component in the drawings may be exaggerated for the sake of explanation and does not mean the size actually applied.

1 is a cross-sectional view showing a cross-sectional view of a see-through solar cell module according to an embodiment. Referring to FIG. 1, the see-through solar cell module according to the embodiment includes a plurality of solar cells C1, C2, and C3. In addition, each of the plurality of solar cells C1, C2, and C3 includes a support substrate 100, a back electrode layer 200, a p-type semiconductor layer 300, a buffer layer 400, and an n-type semiconductor layer 500. Include.

The support substrate 100 has a plate shape and supports the plurality of solar cells C1, C2, and C3. The support substrate 100 may be an insulator. The support substrate 100 may be a glass substrate, a plastic substrate, or a metal substrate. In more detail, the support substrate 100 may be a soda lime glass substrate. The supporting substrate 100 may be transparent. The support substrate 100 may be rigid or flexible.

The back electrode layer 200 including the opening 201 is disposed on the support substrate 100. The back electrode layer 200 may be formed by physical vapor deposition (PVD) or plating.

The rear electrode layer 200 may be formed of any one of molybdenum (Mo), gold (Au), aluminum (Al), chromium (Cr), tungsten (W), and copper (Cu). Among them, in particular, molybdenum (Mo) has a smaller difference between the support substrate 100 and the coefficient of thermal expansion than other elements, and thus it is possible to prevent the occurrence of peeling due to excellent adhesion.

In addition, the back electrode layer 200 includes a first separation pattern P1. The first separation pattern P1 is an open area that exposes an upper surface of the support substrate 100. The width of the first separation pattern P1 may be about 50 μm to about 100 μm. Accordingly, a plurality of back electrodes are formed on the support substrate 100. The back electrode layer 200 may be patterned by a laser, but is not limited thereto.

Referring to FIG. 2, the back electrode layer 200 of the see-through solar cell module according to the embodiment includes an opening 201. The opening 201 functions as a light transmitting unit. That is, the embodiment does not need to form a separate space in order to form the light transmitting portion, and thus the embodiment may provide a high output see-through type solar cell module without power loss.

The back electrode layer 200 is not particularly limited as long as it has a shape including the opening 201. For example, referring to FIG. 3, the back electrode layer 200 may be disposed in the opening 201 and may include first back electrode portions 210 extending in a first direction a.

In contrast, referring to FIG. 4, the back electrode layer 200 may be disposed in the opening 201 and include second back electrode portions 220 extending in a second direction a.

On the contrary, referring to FIG. 5, the rear electrode layer 200 may include the first rear electrode portions 210 disposed in the opening 201 and the second rear electrode portions 220 disposed in the opening 201. It can contain everything. In this case, the first rear electrode portions 210 and the second rear electrode portions 220 may be disposed to cross each other. More preferably, the first rear electrode portions 210 and the second rear electrode portions 220 vertically cross each other, and the rear electrode layer 200 may have a mesh shape, but is limited thereto. It is not.

Referring back to FIG. 1, the p-type semiconductor layer 300 is included on the back electrode layer 200 including the opening. The p-type semiconductor layer 300 includes a?-?-? Group compound. For example, the p-type semiconductor layer 300 may be formed of a copper-indium-gallium-selenide-based (Cu (In, Ga) Se ₂ ; CIGS-based) crystal structure, copper-indium-selenide-based, or copper-gallium- It may have a selenide-based crystal structure.

The p-type semiconductor layer 300 may be formed by a sputtering process or an evaporation method. For example, in order to form the p-type semiconductor layer 300, copper, indium, gallium, selenide-based copper (Cu (In, Ga) Se ₂ ; CIGS while simultaneously or separately evaporating copper, indium, gallium, and selenium). The method of forming the p-type semiconductor layer 300 and the method of forming a metal precursor film and forming it by the selenization process are widely used.

After the metal precursor film is formed and then subjected to selenization, a metal precursor film is formed on the back electrode 200 by a sputtering process using a copper target, an indium target, and a gallium target. Subsequently, the metal precursor film is formed of a p-type semiconductor layer 300 of copper-indium-gallium-selenide (Cu (In, Ga) Se ₂ ; CIGS-based) by a selenization process.

Alternatively, the copper target, the indium target, the sputtering process using the gallium target, and the selenization process may be performed simultaneously.

Alternatively, the CIS-based or CIG-based p-type semiconductor layer 300 may be formed by a sputtering process and a selenization process using only a copper target and an indium target, or using a copper target and a gallium target.

Subsequently, a buffer layer 400 is formed on the p-type semiconductor layer 300. The buffer layer 400 may be disposed between the p-type semiconductor layer 300 and the n-type semiconductor layer 500 to adjust the difference between the lattice constant and the band gap energy, thereby forming a good junction.

The buffer layer 400 includes cadmium sulfide, ZnS, In _x S _y, and In _x Se _y Zn (O, OH). In addition, the buffer layer 400 may be formed by depositing cadmium sulfide on the p-type semiconductor layer 300 by chemical bath deposition (CBD).

Subsequently, a second separation pattern P2 penetrating the p-type semiconductor layer 300 and the buffer layer 400 is formed. The p-type semiconductor layer 300 may be divided into a plurality of light absorbing portions and a plurality of buffer layers by the second separation pattern P2.

Thereafter, an n-type semiconductor layer 500 is formed on the buffer layer 400. The n-type semiconductor layer 500 is transparent and a conductive layer. For example, the n-type semiconductor layer 500 may be formed of boron doped zinc oxide (ZnO: B, BZO), aluminum doped zinc oxide (AZO), or gallium doped zinc oxide (Ga doped zinc). oxide; GZO) and the like. In more detail, the n-type semiconductor layer 500 may use zinc oxide (ZnO: B, BZO) doped with boron in consideration of a band gap and contact with the buffer layer 400.

The n-type semiconductor layer 500 is formed by depositing a transparent conductive material on the buffer layer 400. In addition, in the process of depositing the n-type semiconductor layer 500, the transparent conductive material is also gap-filled to the second separation pattern (P2). The transparent conductive material gap-filled with the second separation pattern P2 may function as a connection wiring for electrically connecting the n-type semiconductor layer 500 and the P-type oxide electrode 200.

The n-type semiconductor layer 500 may be manufactured by sputtering or chemical vapor deposition. In more detail, in order to form the n-type semiconductor layer 500 by the sputtering, a method of depositing using a ZnO target and a reactive sputtering using a Zn target may be used as the RF sputtering method.

Finally, a third separation pattern P3 separating the n-type semiconductor layer 500 is formed. The third separation pattern P3 passes through the n-type semiconductor layer 500, the buffer layer 400, and the p-type semiconductor layer 300 to expose a portion of the back electrode layer 200. That is, according to the third separation pattern P3, the solar cell module according to the embodiment may be divided into a plurality of solar cells C1, C2, and C3.

Referring to FIG. 6, the see-through solar cell module manufactured by the above method uses a rear electrode layer including an opening as a light transmitting part, thereby easily transmitting sunlight L1 incident to the solar cell module (L2). You can.

In addition, the aperture ratio of the solar cell module may be further adjusted by a simple method of varying the width of the third separation pattern P3. For example, the opening ratio of the see-through solar cell module according to the embodiment may be about 20% to about 60%, but is not limited thereto. In addition, the width of the third separation pattern P3 is not limited to a specific value as long as the aperture ratio within the above range can be obtained.

Accordingly, the see-through solar cell module according to the embodiment improves the aperture ratio of the solar cell module by adjusting the back electrode layer 200 and the third separation pattern P3 including the opening, and when used in building exterior materials, particularly windows. Increasing the indoor inflow of external light to provide comfort to the indoor residents can have an effect of improving the living environment.

Features, structures, effects, and the like described in the above embodiments are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified with respect to 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 taken by way of illustration, It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments can be modified and implemented. It is to be understood that all changes and modifications that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims (8)

A rear electrode layer disposed on the supporting substrate;
A p-type semiconductor layer disposed on the back electrode layer; And
An n-type semiconductor layer disposed on the p-type semiconductor layer,
The back electrode layer comprises a solar cell. The method of claim 1,
The back electrode layer is disposed in the opening and includes a first back electrode portion extending in a first direction. 3. The method of claim 2,
The back electrode layer is disposed in the opening and includes a second back electrode portion extending in a second direction crossing the first direction. The method of claim 1,
The back electrode layer is disposed in the opening, the solar cell including first back electrode portions extending in a first direction and second back electrode portions extending in a second direction crossing the first direction. The method of claim 1,
The rear electrode layer is a solar cell (mesh) shape. Forming a back electrode layer on the support substrate;
Forming a p-type semiconductor layer on the back electrode layer; And
Forming an n-type semiconductor layer on the p-type semiconductor layer, wherein the back electrode layer includes an opening
Method for manufacturing a see-through solar cell module. The method according to claim 6,
The forming of the back electrode layer may include forming first back electrode parts disposed in the opening and extending in a first direction. The method of claim 7, wherein
The forming of the back electrode layer may include forming second back electrode parts disposed in the opening and extending in a second direction crossing the first direction.

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