KR20130102204A - Solar cell apparatus and method of fabricating the same - Google Patents

Abstract

PURPOSE: A solar cell apparatus and a method for fabricating the same are provided to obtain visibility by forming transmission parts for exposing the upper surface of a supporting substrate. CONSTITUTION: Cell parts (CP) are located on the surface of a substrate. The cell parts include solar cells (C1,C2,C3). Transmission parts (TP) are adjacent to the cell parts. The transmission parts expose the upper surface of the substrate. The solar cells are extended in a first direction. [Reference numerals] (AA) First direction; (BB) Second direction

Description

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

Embodiments relate to a photovoltaic device and a method of manufacturing the same.

Recently, as the demand for energy increases, the development of a photovoltaic device for converting solar energy into electrical energy is in progress.

In particular, a CIGS-based photovoltaic device, which is a pn heterojunction device having a substrate structure including a glass substrate, a metal back electrode layer, a p-type CIGS-based light absorbing layer, a high resistance buffer layer, an n-type window layer, and the like, is widely used.

In such a photovoltaic device, research is being conducted to improve electrical characteristics such as low resistance and high transmittance.

In particular, there is a demand to utilize such a photovoltaic device as a building glass such as a window, so it is important to secure a transmittance of the photovoltaic device.

Embodiments relate to a solar power generation apparatus capable of controlling solar radiation and a method of manufacturing the same.

Embodiments provide a solar cell apparatus comprising: a plurality of cell units positioned on a substrate and including a plurality of solar cell cells; And a plurality of transmission parts positioned adjacent to the cell part.

Method of manufacturing a solar cell apparatus according to the embodiment comprises the steps of forming a plurality of solar cells; And forming a cell unit including the solar cell and a transmission unit positioned adjacent to the cell unit.

The solar cell apparatus according to the embodiment includes a transmission portion exposing an upper surface of the support substrate. Therefore, when the photovoltaic device is utilized in a window or the like, visibility can be secured through the transmission part. That is, in a portion where the area of the transmissive part is large, the amount of incident light is greater, thereby ensuring transmittance.

Through this, a gradation effect may be given to the solar cell panel. For this reason, it can play the role of solar radiation control of a photovoltaic device, and can improve aesthetics.

In the method of manufacturing a solar cell apparatus according to the embodiment, it is possible to manufacture a solar cell apparatus having the above-described effect.

1 is a schematic plan view of a photovoltaic device according to an embodiment.
2 is a plan view showing a photovoltaic device according to an embodiment.
FIG. 3 is a cross-sectional view taken along the line BB ′ of FIG. 2.

In the description of embodiments, each layer, region, pattern, or structure may be “on” or “under” the substrate, each layer, region, pad, or pattern. Substrate formed in ”includes all 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.

First, referring to FIGS. 1 to 3, a photovoltaic device according to an embodiment will be described in detail.

1 is a schematic plan view of a photovoltaic device according to an embodiment. 2 is a plan view showing a photovoltaic device according to an embodiment. FIG. 3 is a cross-sectional view taken along the line BB ′ in FIG. 2.

1 and 2, the solar cell apparatus according to the embodiment includes a cell unit CP and a transmission unit TP.

The cell unit CP includes a plurality of solar cells C1, C2, and C3. Each of the solar cells C1, C2, and C3 extends in a first direction.

Specifically, referring to FIG. 3, the cell unit CP includes a support substrate 100, a back electrode layer 200, a light absorbing layer 300, a buffer layer 400, a high resistance buffer layer 500, and a front electrode layer 600. It includes.

The support substrate 100 has a plate shape and supports the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, 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. 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 support substrate 100 includes an active region AR and an inactive region NAR. That is, the support substrate 100 is divided into the active area AR and the inactive area NAR.

The active area AR is defined at a central portion of the support substrate 100. The active area AR occupies most of the area of the support substrate 100. The solar cell apparatus according to the embodiment converts sunlight into electrical energy in the active region AR.

The inactive region NAR surrounds the active region AR. The non-active area NAR corresponds to the outside of the support substrate 100. The inactive region NAR may have a very small area compared to the active region AR. The inactive area NAR is an area in which no power is generated.

The rear electrode layer 200 is disposed on the supporting substrate 100. The rear electrode layer 200 is a conductive layer. Examples of the material used as the back electrode layer 200 include a metal such as molybdenum. The back electrode layer 200 is formed in the active region AR and the inactive region NAR.

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.

First through holes TH1 are formed in the back electrode layer 200. The first through holes TH1 are open regions that expose the top surface of the support substrate 100. The first through holes TH1 may have a shape extending in one direction when viewed in a plan view.

The width of the first through holes TH1 may be about 80 μm to 200 μm. By the first through holes TH1, the back electrode layer 200 is divided into a plurality of back electrodes 230 and two connection electrodes 210 and 220. That is, the back electrodes 230, the first connection electrode 210, and the second connection electrode 220 are defined by the first through holes TH1. The back electrode layer 200 includes the back electrodes 230, the first connection electrode 210, and the second connection electrode 220.

The back electrodes 230 are disposed in the active region AR. The back electrodes 230 are disposed side by side. The back electrodes 230 are spaced apart from each other by the first through holes TH1. The back electrodes 230 are arranged in a stripe shape.

Alternatively, the back electrodes 230 may be arranged in a matrix form. At this time, the first through grooves TH1 may be formed in a lattice form when viewed from a plane.

The first connection electrode 210 and the second connection electrode 220 are disposed in the inactive region NAR. That is, the first connection electrode 210 and the second connection electrode 220 extend from the active region AR to the inactive region NAR.

In more detail, the first connection electrode 210 is connected to the front electrode of the first cell C1. In addition, the second connection electrode 220 extends from the back electrode of the second cell C2 to the inactive region NAR. That is, the second connection electrode 220 is integrally formed with the back electrode 202 of the second cell C2.

The light absorbing layer 300 is disposed on the back electrode layer 200. In addition, the material included in the light absorbing layer 300 is filled in the first through holes TH1. The light absorbing layer 300 is disposed in the active region AR. In more detail, the outside of the light absorbing layer 300 may correspond to the outside of the active area AR.

The light absorbing layer 300 includes a group I-III-VI 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 absorbing layer 300. In addition, the buffer layer 400 is disposed in the active region AR. The buffer layer 400 includes cadmium sulfide (CdS), and an energy band gap of the buffer layer 400 is about 2.2 eV to 2.4 eV.

The high resistance buffer layer 500 is disposed on the buffer layer 400. In addition, the high resistance buffer layer 500 is disposed in the active region AR. The high-resistance buffer layer 500 includes zinc oxide (i-ZnO) that is not doped with impurities. The energy bandgap of the high resistance buffer layer 500 is about 3.1 eV to 3.3 eV.

Second through holes (TH2) are formed in the light absorbing layer (300), the buffer layer (400), and the high resistance buffer layer (500). The second through holes (TH2) penetrate the light absorbing layer (300). In addition, the second through holes TH2 are open regions exposing the top surface of the back electrode layer 200.

The second through grooves TH2 are formed adjacent to the first through grooves TH1. That is, a part of the second through grooves TH2 is formed on the side of the first through grooves TH1 when viewed in plan.

The width of the second through holes TH2 may be about 80 μm to about 200 μm.

In addition, the light absorbing layer 300 defines a plurality of light absorbing portions by the second through holes TH2. That is, the light absorbing layer 300 is divided into the light absorbing portions by the second through holes TH2.

In addition, the buffer layer 400 is divided into a plurality of buffers by the second through holes TH2. Similarly, the high resistance buffer layer 500 is divided into a plurality of high resistance buffers by the second through holes TH2.

The front electrode layer 600 is disposed on the high-resistance buffer layer 500. The front electrode layer 600 is disposed in the active region AR.

The front electrode layer 600 is transparent and is a conductive layer. In addition, the resistance of the front electrode layer 600 is higher than the resistance of the back electrode layer 200. For example, the resistance of the front electrode layer 600 may be about 10 to 200 times greater than the resistance of the back electrode layer 200.

 The front electrode layer 600 includes an oxide. For example, the front electrode layer 600 may include zinc oxide, indium tin oxide (ITO), or indium zinc oxide (IZO).

In addition, the oxide may include conductive impurities such as aluminum (Al), alumina (Al 2 O 3), magnesium (Mg), or gallium (Ga). In more detail, the front electrode layer 600 may include aluminum doped zinc oxide (AZO), gallium doped zinc oxide (GZO), or the like. The front electrode layer 600 may have a thickness of about 800 nm to about 1200 nm.

Third through holes TH3 are formed in the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600. The third through holes TH3 are open regions exposing the top surface of the back electrode layer 200. For example, the width of the third through holes TH3 may be about 80 μm to about 200 μm.

The third through grooves TH3 are formed at positions adjacent to the second through grooves TH2. More specifically, the third through-holes TH3 are disposed beside the second through-holes TH2. That is, when viewed in plan, the third through grooves TH3 are arranged next to the second through grooves TH2.

The front electrode layer 600 is divided into a plurality of windows by the third through holes TH3. That is, the windows are defined by the third through holes TH3.

The windows have a shape corresponding to that of the back electrodes 230. That is, the windows are arranged in a stripe shape. Alternatively, the windows may be arranged in a matrix form.

The front electrode layer 600 includes a plurality of connection parts 700 formed by filling a transparent conductive material in the second through holes TH2.

In addition, the first cell C1, the second cell C2, and the plurality of third cells C3 are defined by the third through holes TH3. In more detail, the first cell C1, the second cell C2, and the third cells C3 are defined by the second through holes TH2 and the third through holes TH3. do. That is, the solar cell apparatus according to the embodiment includes the first cell C1, the second cell C2, and the third cells C3 disposed on the support substrate 100.

The third cells C3 are disposed between the first cell C1 and the second cell C2. The first cell C1, the second cell C2, and the third cells C3 are connected in series with each other. That is, the first cell C1, the second cell C2, and the third cells C3 extend in the first direction.

The connection parts 700 are disposed inside the second through holes TH2. The connection parts 700 extend downward from the front electrode layer 600 and are connected to the back electrode layer 200.

Thus, the connection parts 700 connect adjacent cells to each other. In more detail, the connection parts 700 connect the windows and the rear electrodes included in the cells adjacent to each other.

The outer edges of the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 may substantially coincide with each other. That is, the outer edges of the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 may correspond to each other. In this case, an outer edge of the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 may coincide with a boundary between the active region AR and the inactive region NAR. Can be.

Meanwhile, the cell part CP extends in a second direction crossing the first direction. The cell unit CP is provided in plurality.

In detail, the cell unit CP may include a first cell unit 1CP and a second cell unit 2CP. The first cell unit 1CP and the second cell unit 2CP may be located along the first direction.

The transmission part TP is positioned adjacent to the cell part CP. The transmission part TP extends in the second direction. The transmission part TP is provided in plurality.

Specifically, the transmission part TP may include a first transmission part 1TP and a second transmission part 2TP. The first transmission part 1TP and the second transmission part 2TP may be located along the first direction.

The transmission part TP exposes an upper surface of the support substrate 100. Accordingly, in the transmission part TP, the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 included in the cell part CP are omitted.

The cell part CP is positioned between the transmission part TP. In detail, the first cell part 1CP is positioned between the first transmission part 1TP and the second transmission part 2TP. Similarly, the second transmission part 2TP is positioned between the first cell part 1CP and the second cell part 2CP.

On the other hand, the support substrate 100 includes a first region 1A and a second region 2A positioned adjacent to the first region 1A. The total area of the transmission part TP included in the first area 1A and the second area 2A may be different from each other.

For example, as shown in FIG. 1, when the upper portion of the solar cell panel is defined as the first region 1A and the lower portion of the first region 1A is defined as the second region 2A, The total area of the transmission part TP included in the first area 1A and the second area 2A may be different from each other.

Referring to FIG. 2, the total area of the transmission portion TP included in the first region 1A may be smaller than the total area of the transmission portion TP included in the second region 2A. That is, the number of transmission parts TP included in the second area 2A may be greater than the first area 1A, or the interval between the transmission parts TP may be narrower than that of the first area 1A. Therefore, when the photovoltaic device is utilized in a window or the like, visibility can be secured through the second area 2A. That is, the amount of light incident on the second region 2A is greater, thereby ensuring transmittance.

Through this, a gradation effect may be given to the solar cell panel. For this reason, it can play the role of solar radiation control of a photovoltaic device, and can improve aesthetics.

Meanwhile, the first bus bar 11 is disposed in the inactive area NAR. The first bus bar 11 is disposed on the back electrode layer 200. In more detail, the first bus bar 11 is disposed on the first connection electrode 210. The first bus bar 11 may directly contact an upper surface of the first connection electrode 210.

The first bus bar 11 extends in parallel with the first cell C1. The first bus bar 11 may extend to the rear surface of the support substrate 100 through a hole formed in the support substrate 100. The first bus bar 11 is connected to the first cell C1. In more detail, the first bus bar 11 is connected to the first cell C1 through the first connection electrode 210.

The second bus bar 12 is disposed in the inactive area NAR. The second bus bar 12 is disposed on the back electrode layer 200. In more detail, the second bus bar 12 is disposed on the second connection electrode 220. The second bus bar 12 may directly contact an upper surface of the second connection electrode 220.

The second bus bar 12 extends in parallel with the second cell C2. The second bus bar 12 may extend to the rear surface of the support substrate 100 through a hole formed in the support substrate 100. The second bus bar 12 is connected to the second cell C2. In more detail, the second bus bar 12 is connected to the second cell C2 through the second connection electrode 220.

The first bus bar 11 and the second bus bar 12 face each other. In addition, the first bus bar 11 and the second bus bar 12 may be symmetrical to each other. The first bus bar 11 and the second bus bar 12 are conductors. The first bus bar 11 and the second bus bar 12 may include a metal having high conductivity such as silver.

The first bus bar 11 is connected to the first cell through the first connection electrode 210. In more detail, the first bus bar 11 is connected to the window of the first cell C1 through the first connection electrode 210.

The second bus bar 12 is connected to the second cell C2 through the second connection electrode 220. In more detail, the second bus bar 12 is connected to the rear electrode of the second cell C2 through the second connection electrode 220.

The first bus bar 11 and the second bus bar 12 may be connected to the back electrode layer 200 by direct contact. In this case, the first bus bar 11 and the second bus bar 12 may include a metal such as silver, and likewise, the back electrode layer 200 may also include a metal such as molybdenum. Accordingly, the contact characteristics between the first bus bar 11 and the second bus bar 12 and the back electrode layer 200 are improved.

The first bus bar 11 and the second bus bar 12 may extend along the first direction.

Hereinafter, the manufacturing method of the solar cell apparatus according to the embodiment. For the sake of clarity and simplicity, the same or similar parts as those described above will be omitted.

A method of manufacturing a solar cell apparatus according to an embodiment includes forming a plurality of solar cells C1, C2, and C3, and forming a transmission part TP.

Forming the solar cells (C1, C2, C3), forming the back electrode layer 200, forming the light absorbing layer 300, forming the buffer layer 400, high resistance buffer layer ( Forming the front electrode layer 600 and forming the front electrode layer 600.

First, the back electrode layer 200 is formed on the support substrate 100, and the back electrode layer 200 is patterned to form first through holes TH1. Accordingly, a plurality of back electrodes 230, a first connection electrode 210, and a second connection electrode 220 are formed on the support substrate 100. The rear electrode layer 200 is patterned by a laser.

The first through holes TH1 expose the upper surface of the supporting substrate 100 and may have a width of about 80 mu m to about 200 mu m.

An additional layer such as a diffusion barrier layer may be interposed between the supporting substrate 100 and the back electrode layer 200. The first through holes TH1 expose the upper surface of the additional layer .

The light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 are formed on the back electrode layer 200. The light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 are formed in the active region AR.

The light absorbing layer 300 may be formed on the support substrate 100 by a sputtering process or an evaporation method.

For example, a copper-indium-gallium-selenide-based (Cu (In, Ga) Se 2; CIGS-based) light-emitting layer is formed while simultaneously evaporating copper, indium, gallium, A method of forming the light absorbing layer 300 and a method of forming the metal precursor film by a selenization process are widely used.

When a metal precursor film is formed and then subjected to selenization, a metal precursor film is formed on the rear electrode 200 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 300 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.

Cadmium sulfide is deposited by a sputtering process, a chemical bath depositon (CBD), or the like, and the buffer layer 400 is formed.

Then, zinc oxide is deposited on the buffer layer 400 by a sputtering process or the like, and the high-resistance buffer layer 500 is formed.

The buffer layer 400 and the high resistance buffer layer 500 are deposited to a low thickness. For example, the thickness of the buffer layer 400 and the high resistance buffer layer 500 is about 1 nm to about 80 nm.

Thereafter, a portion of the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 is removed to form second through holes TH2.

The second through grooves TH2 may be formed by a mechanical device such as a tip or a laser device.

For example, the light absorbing layer 300 and the buffer layer 400 may be patterned by a tip having a width of about 40 μm to about 180 μm. In addition, the second through holes TH2 may be formed by a laser having a wavelength of about 200 to 600 nm.

In this case, the width of the second through holes TH2 may be about 100 μm to about 200 μm. In addition, the second through holes TH2 are formed to expose a portion of the top surface of the back electrode layer 200.

The front electrode layer 600 is formed on the light absorbing layer 300 and inside the second through holes TH2. That is, the front electrode layer 600 is formed by depositing a transparent conductive material on the high resistance buffer layer 500 and inside the second through holes TH2.

In this case, the transparent conductive material is filled in the second through holes TH2, and the front electrode layer 600 is in direct contact with the back electrode layer 200.

Thereafter, a portion of the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 is removed to form third through holes TH3. Accordingly, the front electrode layer 600 is patterned to define a plurality of windows, a first cell C1, a second cell C2, and a third cell C3. The width of the third through holes TH3 may be about 80 μm to about 200 μm.

Subsequently, in the forming of the transmission part TP, the transmission part TP may be formed by scribing a part of the solar cell. In this case, an area of the transmission part TP may vary according to the interval or number of scribing.

In the forming of the transmission part TP, the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the front electrode layer 600 may be scribed. Therefore, the upper surface of the support substrate 100 may be exposed by forming the transmission part TP.

 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. 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 (15)

A plurality of cell units disposed on the substrate and including a plurality of solar cell cells; And
A photovoltaic device comprising a plurality of transmission portions positioned adjacent to the cell portion. The method of claim 1,
The transmission unit is a solar cell apparatus for exposing the upper surface of the substrate. The method of claim 1,
The cell unit is located between the transmission unit. The method of claim 1,
The solar cell extends in the first direction,
The cell unit extends in a second direction crossing the first direction. 5. The method of claim 4,
The cell part includes a first cell part and a second cell part located in a first direction from the first cell part.
The transmission part includes a first transmission part and a second transmission part located along the first direction from the first transmission part. The method of claim 5,
The first cell unit is located between the first transmission unit and the second transmission unit. The method of claim 5,
The second transmission portion is a solar cell apparatus located between the first cell portion and the second cell portion. 5. The method of claim 4,
The cell unit
Board;
A rear electrode layer disposed on the upper surface of the substrate;
A light absorbing layer disposed on the rear electrode layer; And
A photovoltaic device comprising a front electrode layer disposed on the light absorbing layer. 9. The method of claim 8,
A bus bar disposed next to the light absorbing layer and connected to the back electrode layer;
The bus bar extends along the first direction. The method of claim 1,
The substrate includes a first region and a second region positioned adjacent to the first region,
The solar cell apparatus of claim 1, wherein the total area of the transmission part included in the first area and the second area is different from each other. Forming a plurality of solar cells; And
And forming a cell unit including the solar cell and a transmission unit positioned adjacent to the cell unit. 12. The method of claim 11,
Forming the solar cell is,
Forming a back electrode layer on the support substrate;
Forming a light absorbing layer on the back electrode layer;
Forming a buffer layer on the light absorbing layer;
Forming a front electrode layer on the buffer layer; And
The method of manufacturing a solar cell apparatus comprising the step of forming the front electrode layer. 12. The method of claim 11,
The forming of the transmitting part is a method of manufacturing a photovoltaic device for scribing a portion of the solar cell. The method of claim 12,
The forming of the transmitting part may include scribing the back electrode layer, the light absorbing layer, the buffer layer, and the front electrode layer. The method of claim 12,
In the step of forming the transmission portion manufacturing method of a photovoltaic device that the upper surface of the support substrate is exposed.

Images