KR20130040017A - Solar cell module and method of fabricating the same - Google Patents

Abstract

PURPOSE: A solar cell module and a manufacturing method thereof are provided to prevent moisture or oxygen from penetrating into the solar cell module through an interface, by forming a moisture blocking part in the outer region of a support substrate. CONSTITUTION: A support substrate(10) has a center region(CR) and an edge region(OR). A solar cell(20) is arranged in the center region of the support substrate. A moisture blocking part(30) is arranged in the edge region of the support substrate. A separation pattern(P4) is arranged between the center region and the edge region. The separation pattern separates the moisture blocking part from the solar cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a solar cell module,

The embodiment relates to a 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.

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 module manufactured by connecting several solar cells in series on a substrate to obtain a voltage of several V to several hundred V or more is called a module, and installing a plurality of modules in a frame is called a photovoltaic device. .

Photovoltaic devices generally consist of glass / filler (ethylene vinyl acetate (EVA)) / solar cell module / filler (EVA) / surface material (backsheet).

In general, glass uses low iron tempered glass, which requires high light transmittance and a process for reducing surface light reflection loss. EVA, which is used as a filler, is a material inserted between the front and rear surfaces of the solar cell and the surface material to protect the fragile solar cell device. Since EVA may cause discoloration and poor moisture resistance when exposed to ultraviolet rays for a long period of time, it is important to adopt a process suitable for the characteristics of the EVA sheet during module manufacturing to extend module life and to ensure reliability. The back sheet is located on the back of the solar cell module, and should have good adhesion between the layers, be easy to handle, and protect the solar cell device from the external environment.

The photovoltaic device must be resistant to moisture (H ₂ O) or oxygen (O ₂ ) from the outside, and solving such reliability problems is one of the important factors in solar cell performance. Conventionally, in order to solve such a problem, a sealing treatment has been performed on the solar cell. However, even though the sealing treatment is performed, the solar cell electrode is corroded due to moisture penetrating into the solar cell through the interface between the substrate and the sealing. There is a problem that degrades the performance.

The embodiment is to provide a solar cell module and a method of providing the same improved reliability and stability.

The solar cell according to the embodiment includes a plurality of solar cells disposed on a central area of the support substrate; A moisture barrier disposed on an outer region of the support substrate; And a separation pattern disposed between the central area and the outer area.

A method of manufacturing a solar cell according to the embodiment includes forming a plurality of solar cells on a support substrate; And forming a separation pattern that separates the central area and the outer area of the support substrate, thereby separating and forming the solar cells disposed on the center area and the water blocking part disposed on the outer area.

The solar cell module according to the embodiment forms a moisture barrier in the outer region of the support substrate. Accordingly, the penetration path of moisture (H ₂ O) or oxygen (O ₂ ) may be extended, and the penetration of moisture or oxygen into the solar cell module along the interface may be minimized. That is, the solar cell according to the embodiment effectively contributes to securing the stability and reliability of the device by effectively protecting the solar cells from moisture and oxygen.

The solar cell module manufacturing method according to the embodiment may be manufactured together with the moisture blocking part in the process of manufacturing the solar cell module without an additional process. In addition, the manufacturing method of the solar cell module according to the embodiment forms a separation pattern by a two-step process including a mechanical process and a laser process, in order to separate and form the solar cell module and the water blocking unit. Accordingly, it is possible to form a precise separation pattern without losing the active area AA, and to reduce the process cost and time.

1 is a plan view illustrating a top surface of a solar cell module according to an embodiment.
FIG. 2 is a cross-sectional view illustrating a cross section taken along AA ′ of FIG. 1.
3 to 7 are cross-sectional views illustrating a method of manufacturing the 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 plan view illustrating a top surface of a solar cell module according to an embodiment. FIG. 2 is a cross-sectional view illustrating a cross section taken along the line AA ′ of FIG. 1. 1 and 2, the solar cell according to the embodiment includes a support substrate 10, a plurality of solar cells 20, a moisture blocking unit 30, and a separation pattern P4.

The support substrate 10 has a plate shape and supports the solar cells 20 and the moisture blocking unit 3. The support substrate 10 may be transparent, rigid or flexible. In addition, the support substrate 10 may be an insulator.

For example, the support substrate 10 may be a glass substrate, a plastic substrate, or a metal substrate. In more detail, the support substrate 10 may be a soda lime glass substrate.

Alternatively, a ceramic substrate such as alumina, stainless steel, a flexible polymer, or the like may be used as the material of the support substrate 10.

The support substrate 10 may be divided into a central region CR and an outer region OR. The central region CR refers to an active area AA in which the solar cells 20 are formed. The central area CR may include an area excluding a peripheral area of the support substrate 10.

In addition, the outer region OR is a region surrounding the central region CR, and means a non-active area NAA in which the solar cells 20 are not formed. For example, the outer region OR may refer to an inner region of about 10 mm to about 200 mm from the outermost portion of the support substrate 10, but is not limited thereto.

The solar cells 20 are disposed on the central region CR of the support substrate 10. The solar cells 20 include a plurality of solar cells, and the plurality of solar cells are electrically connected to each other. For example, the plurality of solar cells may be connected in series with each other, but is not limited thereto. Accordingly, the solar cells 20 may convert sunlight into electrical energy.

Referring to FIG. 2, the solar cells 20 may include a back electrode layer 200 disposed on the support substrate 10, a light absorbing layer 300 disposed on the back electrode layer 200, and the light absorbing layer ( And a front electrode layer 600 disposed on 300. The solar cells 20 may further include a buffer layer 400 and a high resistance buffer layer 500 between the light absorbing layer 300 and the front electrode layer 600, but are not limited thereto.

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 10 and the coefficient of thermal expansion than other elements, and thus it is possible to prevent peeling from occurring due to excellent adhesion.

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

The buffer layer 400 is disposed on the light absorption layer 300. The buffer layer 400 includes cadmium sulfide, ZnS, In _x S _y, and In _x Se _y Zn (O, OH). 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 front electrode layer 600 may be disposed on the light absorbing layer 300. For example, the front electrode layer 600 may be disposed in direct contact with the high-resistance buffer layer 500 on the light absorption layer 300.

The front electrode layer 600 may be formed of a light-transmitting conductive material. In addition, the front electrode layer 600 may have characteristics of an n-type semiconductor. At this time, the front electrode layer 600 may form an n-type semiconductor layer together with the buffer layer 400 to form a pn junction with the light absorbing layer 300 which is a p-type semiconductor layer.

The moisture blocking unit 30 is disposed on the support substrate 10. In more detail, the moisture blocking unit 30 may be disposed in the outer region OR of the support substrate 10. As mentioned above, the outer area OR is an area surrounding the central area CR, and means a non-active area NAA in which the solar cells 20 are not formed. For example, the outer region OR may refer to an inner region of about 10 mm to about 200 mm from the outermost portion of the support substrate 10, but is not limited thereto.

The moisture blocking unit 30 may be formed of the same layer as the solar cells 20. That is, the moisture blocking unit 30 includes a back electrode layer 200, a light absorbing layer 300, and a front electrode layer 50 forming the solar cells 20. In more detail, the moisture blocking unit 30 is the rear electrode layer 200, the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 which are sequentially formed on the support substrate 10. And the front electrode layer 600.

That is, the moisture blocking unit 30 may be formed by stacking the same layer in the process of forming the solar cells 20. Thereafter, the moisture blocking unit 30 may be separated from the solar cells 20 by the separation pattern P4. Thus, the moisture barrier 30 may be manufactured by a simple process without the additional process for forming the moisture barrier.

The width of the moisture barrier 30 may be about 10 mm to about 50 mm. In more detail, the width of the moisture barrier 30 may be about 10 mm to about 20 mm, but is not limited thereto.

The separation pattern P4 is disposed between the central region CR of the support substrate 10 and the outer region OR of the support substrate 10. The separation pattern P4 may separate the solar cells 20 and the moisture blocking unit 30. That is, the separation pattern P4 blocks the moisture cells disposed on the solar cells 20 disposed on the center region CR of the support substrate 10 and the outer region OR of the support substrate 10. The parts 30 may be spaced apart from each other. The separation pattern P4 may have a width of about 10 μm to about 100 μm. In more detail, the width of the separation pattern P4 may be about 50 μm to about 100 μm, but is not limited thereto.

As mentioned above, the solar cell module according to the embodiment includes a water blocking unit 30 and a separation pattern P4 formed in the outer region OR of the support substrate 10. The moisture blocking unit 30 and the separation pattern P4 may form a step to extend the penetration path of the water (H ₂ O) or oxygen (O ₂ ) than the conventional solar cell module.

Although not shown in the drawings, the solar cell module according to the embodiment may further include a polymer adhesive layer and a protection panel.

The polymer adhesive layer (not shown) is disposed on the support substrate 10. In more detail, the polymer adhesive layer may be disposed in direct contact with the moisture blocking unit 30 and the solar cells 30. The separation pattern P4 may increase the contact area between the solar cell module and the polymer adhesive layer. Therefore, the solar cell according to the embodiment may minimize the penetration of moisture or oxygen into the solar cell along the interface between the moisture blocking unit 30 and the polymer adhesive layer.

The polymer adhesive layer may be transparent and flexible. The polymer adhesive layer may include a transparent plastic. In more detail, the polymer adhesive layer may include ethylene vinyl acetate resin and the like.

The protective panel may be disposed on the polymer adhesive layer. The protection panel protects the solar cells 20 from external physical shocks and / or foreign matter. The protective panel is transparent and may include, for example, tempered glass.

3 to 7 are cross-sectional views illustrating a method of manufacturing the solar cell module according to the embodiment. The description of this manufacturing method refers to the description of the solar cell module described above.

Referring to FIG. 3, the back electrode layer 200 is formed on the support substrate 10. The back electrode layer 200 may be formed by physical vapor deposition (PVD) or plating. The back electrode layer 200 includes a first pattern P1. That is, the back electrode layer 200 may be patterned on the first pattern P1. In addition, as shown in FIG. 3, the first pattern P1 may be formed in various shapes such as a matrix shape as well as a stripe shape. For example, the width of the first pattern P1 may be about 80 μm to about 300 μm, but is not limited thereto.

Referring to FIG. 4, a light absorbing layer 300, a buffer layer 300, and a high resistance buffer layer 500 are formed on the rear electrode layer 200. Subsequently, a second pattern P2 is formed on the light absorbing layer 300, the buffer layer 300, and the high resistance buffer layer 500.

The light absorbing layer 300 may be, for example, copper-indium-gallium-selenide-based (Cu (In, Ga) Se ₂ ; CIGS-based) while simultaneously evaporating copper, indium, gallium, and selenium. The method of forming (300) and the method of forming a metal precursor film and forming it by the selenization process are used widely.

When the metal precursor film is formed and selenization is subdivided, a metal precursor film is formed on the back electrode 300 by a sputtering process using a copper target, an indium target, and a gallium target. Thereafter, the metal precursor film is formed of a copper-indium-gallium-selenide-based (Cu (In, Ga) Se ₂ ; CIGS-based) light absorbing layer 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 optical absorption layer 300 can be formed by using only a copper target and an indium target, or by a sputtering process and a selenization process using a copper target and a gallium target.

Thereafter, the buffer layer 400 may be formed by depositing cadmium sulfide on the light absorbing layer 300 by chemical bath deposition (CBD). In addition, zinc oxide is deposited on the buffer layer 400 by a sputtering process, and the high resistance buffer layer 500 is formed.

Referring to FIG. 4, a second pattern P2 is formed on the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500. The second pattern P2 may be formed by a mechanical method, and a portion of the back electrode layer 200 is exposed. The second pattern P2 penetrates the light absorbing layer 300. Accordingly, the second pattern P2 may expose the top surface of the back electrode layer 200. In addition, the width of the second pattern P2 may be about 80 μm to about 300 μm, but is not limited thereto.

Subsequently, as illustrated in FIG. 5, a transparent conductive material is stacked on the high resistance buffer layer 500 to form a front electrode layer 600 and a connection wiring 700 which are second electrodes. When the transparent conductive material is stacked on the high resistance buffer layer 500, the transparent conductive material may also be inserted into the second pattern P2 to form the connection wiring 600. The back electrode layer 300 and the front electrode layer 600 are electrically connected by the connection wiring 600.

The front electrode layer 600 is a window layer forming a pn junction with the light absorbing layer 300. Since the front electrode layer functions as a transparent electrode on the front of a solar cell, zinc oxide (ZnO) having high light transmittance and good electrical conductivity is provided. It can be formed as.

In this case, the front electrode layer 600 having a low resistance value may be formed by doping aluminum to the zinc oxide. For example, the front electrode layer 600 may be formed by depositing using a ZnO target by RF sputtering, reactive sputtering by using a Zn target, and organometallic chemical vapor deposition.

Subsequently, as illustrated in FIG. 5, a third pattern P3 penetrating the light absorbing layer 300, the buffer layer 300, the high resistance buffer layer 500, and the front electrode layer 600 is formed. The solar cell unit cells C1, C2, C3 .. may be distinguished from each other by the third pattern P3, and the solar cell 20 is connected to each other by the connection wiring 350. The third pattern P3 may be formed by a mechanical method, or may be formed by irradiating a laser, and may be formed to expose the top surface of the back electrode layer 200.

6 and 7, the solar cells 20 are patterned to separate the solar cells 20 and the water blocking unit 30. In more detail, the solar cells 20 and the moisture blocking unit 30 may be distinguished from each other by a separation pattern P4.

Referring to FIG. 6, first, a first through hole TH1 penetrating the front electrode layer 600, the high resistance buffer layer 500, and the light absorbing layer 300 is formed. A portion of the back electrode layer 200 may be exposed by the first through hole. By forming the first through hole TH1, it is possible to form a fine separation pattern P4 without losing an active area AA in the process of forming the second through hole TH2.

The first through hole TH1 may be formed by a mechanical method, or may be formed by irradiating a laser. More specifically, the first through hole TH1 may be formed by a mechanical method. It can be formed by the phosphorus method. For example, the first through hole TH1 may be manufactured by a scribing process using a tip.

Referring to FIG. 7, a second through hole TH2 penetrating the exposed rear electrode layer 200 is formed. A portion of the support substrate 10 may be exposed by the second through groove TH2. In more detail, the second through hole TH2 is formed on the same region as the first through hole TH1.

By forming the second through hole TH2, the separation pattern P4 may be completed. In addition, the solar cell module 20 and the water blocking unit 30 may be spaced apart from each other by the separation pattern P4.

The second through hole TH2 may be formed by a mechanical method, or may be formed by irradiating a laser. More specifically, the second through hole TH1 may be formed by a laser. It can be formed by irradiating.

As mentioned above, the method of manufacturing a solar cell module according to the embodiment is separated by a two-step process including a mechanical process and a laser process to separate and form the solar cell module 20 and the water blocking unit 30. The pattern P4 is formed. Accordingly, it is possible to form a precise separation pattern without losing the active area AA, and to reduce the process cost and time.

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 (11)

A plurality of solar cells disposed on a central region of the support substrate;
A moisture barrier disposed on an outer region of the support substrate;
The solar cell module comprising a separation pattern disposed between the central region and the outer region.
The method of claim 1,
The solar cell module and the solar cell are spaced apart from each other by the separation pattern.
3. The method of claim 2,
The width of the separation pattern is a solar cell module 10 ㎛ to 100 ㎛.
The method of claim 1,
The solar cell module includes a rear electrode layer, a light absorbing layer and a front electrode layer sequentially formed on the central region.
The method of claim 4, wherein
The moisture blocking unit includes the back electrode layer, the light absorbing layer and the front electrode layer.
The method of claim 1,
A width of the moisture blocking unit is 10 mm to 50 mm solar cell module.
The method of claim 1,
The solar cell module further comprises a polymer adhesive layer disposed on the solar cells and the moisture blocking unit.
Forming a plurality of solar cells on a support substrate; And
Forming a separation pattern that separates the central region and the outer region of the support substrate, thereby separating and forming the solar cells disposed on the central region and the moisture blocking unit disposed on the outer region. Manufacturing method.
The method of claim 8,
Forming the solar cells,
Forming a rear electrode layer on the support substrate;
Forming a light absorbing layer on the back electrode layer; And
A method of manufacturing a solar cell module comprising forming a front electrode layer on the light absorbing layer.
The method of claim 9,
The separation pattern is,
Forming a first through hole penetrating the front electrode layer and the light absorbing layer to expose the rear electrode layer;
And forming a second through hole penetrating the exposed rear electrode layer to expose the support substrate.
11. The method of claim 10,
The first through hole is formed by a mechanical process,
The second through groove is a method of manufacturing a solar cell module formed by a laser process.

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