KR20100109319A - Solar cell and method of fabricating the same - Google Patents

Abstract

PURPOSE: A solar power generation device and a manufacturing method thereof are provided to have improved efficiency and to easily separate a plurality of cells. CONSTITUTION: A solar power generation device includes a substrate(100), electrodes(200), first insulating members(810), light absorption parts, and windows. The electrodes are arranged on the substrate and are separated from each other. The first insulating members are interposed between the electrodes. The light absorption parts are arranged on the electrodes. The windows are arranged on the light absorption parts.

Description

SOLAR CELL AND METHOD OF MANUFACTURING THEREOF {SOLAR CELL AND METHOD OF FABRICATING THE SAME}

The embodiment relates to a photovoltaic device and a method of manufacturing the same.

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

In particular, CIGS-based solar cells that are pn heterojunction devices 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 are widely used.

In addition, to form such a solar cell, a mechanical patterning process may be performed. At this time, by the dead zone is formed by patterning, which is not used for power generation, the power generation efficiency of the solar cell can be reduced.

Embodiments provide a photovoltaic device having improved efficiency.

Photovoltaic device according to one embodiment includes a substrate; A plurality of electrodes disposed on the substrate and spaced apart from each other; A plurality of first insulating members interposed between the electrodes; A plurality of light absorbing parts disposed on the electrodes; And a plurality of windows disposed on the light absorbing portions.

The photovoltaic device according to an embodiment may further include a plurality of second insulating members interposed between the windows.

The solar cell apparatus according to the embodiment further includes a buffer sheet disposed on the windows, and the second insulating members may be integrally formed with the buffer sheet.

In one embodiment, the second insulating members may be interposed between the light absorbing portions.

In one embodiment, the first insulating members and the second insulating members may include.

In an embodiment, the top surface of the first insulating members and the top surface of the electrodes may be disposed on the same plane.

According to one or more exemplary embodiments, a method of manufacturing a solar cell apparatus includes: forming a plurality of electrodes on a substrate; Forming a plurality of first insulating members between the electrodes, respectively; Forming light absorbing portions on the electrodes; And forming windows on the light absorbing portions.

The solar cell apparatus according to the embodiment includes first insulating members interposed between the electrodes and second insulating members interposed between the windows.

Therefore, the solar cell apparatus according to the embodiment can efficiently insulate between the electrodes, and can efficiently insulate the windows.

That is, in the solar cell apparatus according to the embodiment, a plurality of cells can be easily separated by the first insulating members and the second insulating members.

Therefore, the solar cell apparatus according to the embodiment can reduce the gap between the cells, thereby reducing the short and leakage current.

Therefore, the solar cell apparatus according to the embodiment has improved efficiency.

In the description of the embodiments, it is described that each substrate, film, electrode, groove or layer or the like is formed "on" or "under" of each substrate, electrode, film, groove or layer or the like. In the case, “on” and “under” include both being formed “directly” or “indirectly” through 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 section of the solar cell apparatus according to the embodiment.

Referring to FIG. 1, the photovoltaic device 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, a window layer 600, and connection portions ( 700, first insulating members 810, and second insulating members 820.

The support substrate 100 has a plate shape, and the back electrode layer 200, the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, the window layer 600, and the connection parts 700 are provided. ) And the first insulating members 810 and the second insulating members 820.

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 support substrate 100 may be transparent. The support substrate 100 may be rigid or flexible.

The back electrode layer 200 is disposed on the support substrate 100. The back electrode layer 200 is a conductive layer. Examples of the material used for the back electrode layer 200 include a metal such as molybdenum.

In addition, the back electrode layer 200 may include two or more layers. In this case, each of the layers may be formed of the same metal, or may be formed of different metals.

The back electrode layer 200 includes a plurality of back electrodes 210, 220... Which are separated by the first through hole TH1. The back electrodes 210, 220... Are spaced apart from each other. An interval between the back electrodes 210, 220... May be about 10 nm to 70 μm.

The back electrodes 210, 220... Are arranged in a stripe shape. The back electrodes 210, 220... Correspond to the respective cells C1, C2.

Alternatively, the back electrodes 210, 220... May be arranged in a matrix form.

The light absorbing layer 300 is disposed on the back electrode layer 200. The light absorbing layer 300 includes a Group I-Group III-VI compound. For example, the light absorbing 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-selenide It may have a system crystal structure.

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

The light absorbing layer 300 includes a plurality of light absorbing portions 310, 320... Which are divided by a second through hole TH2 and a third through hole TH3. The light absorbing parts 310 and 320... Are spaced apart from each other, and correspond to the back electrodes 210, 220.

The buffer layer 400 is disposed on the light absorbing layer 300. The buffer layer 400 includes cadmium sulfide (CdS), and the energy band gap of the buffer layer 400 is about 2.2 eV to 2.4 eV.

The buffer layer 400 includes a plurality of buffers 410, 420... Which are divided by the second through hole TH2 and the third through hole TH3. The buffers 410, 420... Are spaced apart from each other. In addition, the buffers 410, 420... Correspond to the light absorbing portions 310, 320.

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 bandgap of the high resistance buffer layer 500 is about 3.1 eV to 3.3 eV.

The high resistance buffer layer 500 includes a plurality of high resistance buffers 510, 520... Which are divided by the second through hole TH2 and the third through hole TH3. The high resistance buffers 510, 520... Are spaced apart from each other. In addition, the high resistance buffers 510, 520... Correspond to the light absorbing portions 310, 320.

The window layer 600 is disposed on the high resistance buffer layer 500. The window layer 600 is transparent and is a conductive layer. Examples of the material used as the window layer 600 include aluminum doped ZnO (AZO).

The window layer 600 includes a plurality of windows 610, 620... Which are divided by the third through hole TH3. The windows 610, 620 ... are spaced apart from each other. The spacing between the windows 610, 620... Is about 10 nm to about 70 μm.

The windows 610, 620... Have a shape corresponding to the back electrodes 210, 220. That is, the windows 610, 620... Are arranged in a stripe shape. Alternatively, the windows 610, 620... May be arranged in a matrix form.

The window layer 600 is an n-type conductive layer for supplying holes to the light absorbing layer 300. In addition, the windows 610, 620... May perform an electrode function.

The second through hole TH2 penetrates the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500, and the third through hole TH3 is the light absorbing layer 300 and the buffer layer. 400, penetrate the high resistance buffer layer 500 and the window layer 600.

In addition, a plurality of cells C1, C2... Are defined by the third through hole TH3. That is, the photovoltaic device according to the embodiment is divided into the cells C1, C2... By the third through hole TH3.

The connection parts 700 are disposed on side surfaces of the absorbers, the buffers 410, 420..., And the high resistance buffers 510, 520. That is, the connection parts 700 are disposed inside the second through hole TH2. The connection parts 700 extend downward from the window layer 600, respectively, and directly contact the back electrode layer 200.

Accordingly, the connection part 700 connects the window and the back electrode included in the cells C1, C2 ... adjacent to each other. That is, the connection part 700 connects the window 610 included in the first cell C1 and the back electrode 220 included in the second cell C2 adjacent to the first cell C1.

The connection parts 700 are integrally formed with the windows 610, 620... That is, the material used as the connection parts 700 is the same as the material used as the window layer 600.

The first insulating members 810 are interposed between the back electrodes 210, 220. That is, the first insulating member 810 is disposed inside the first through hole TH1.

The first insulating members 810 are insulators and insulate between the back electrodes 210, 220. Examples of the material used as the first insulating members 810 include ethylenevinylacetate (EVA), polyethylene terephthalate (PET), polycarbonate (PC), and polyimide (PI). And a polymer material having excellent light transmittance, and the like.

Unlike FIG. 1, the top surfaces of the first insulating members 810 may be disposed on the same plane as the top surfaces of the back electrodes 210, 220.

The second insulating members 820 are interposed between the windows 610 and 620, respectively. In addition, the second insulating members 820 may be interposed between the light absorbing portions 310 and 320, respectively. Similarly, the second insulating members 820 may be interposed between the buffers 410, 420...

That is, the second insulating member 820 is disposed inside the third through hole TH3.

The second insulating members 820 insulate between the windows 610, 620. In addition, the second insulating members 820 may insulate the light absorbing parts 310, 320.

Examples of the material used as the second insulating members 820 include a polymer material having excellent light transmittance such as EVA, PET, PC, and PI.

The photovoltaic device according to the embodiment may include a protective film disposed on the window layer 600. The protective film protects the window layer 600. In addition, the protective film may perform an antireflection function so that light is incident on the window layer 600 efficiently. In addition, the protective film may perform a buffer film function.

In this case, the second insulating members 820 may be integrally formed with the protective film.

The first insulating member 810 insulates the back electrodes 210, 220... Accordingly, the first insulating member 810 prevents short between the back electrodes 210, 220...

In addition, the second insulating member 820 insulates the windows 610, 620... Accordingly, the second insulating member 820 prevents a short between the windows 610, 620...

Therefore, the solar cell apparatus according to the embodiment can prevent the short between the cells C1, C2 ....

In addition, by the first insulating member 810, the distance between the back electrodes 210, 220..., That is, the width of the first through hole TH1 may be reduced. Similarly, the gap between the windows 610, 620..., That is, the width of the third through hole TH3 may be reduced by the second insulating member 820.

The first through hole TH1, the second through hole TH2, and the third through hole TH3 are dead zones that do not perform a function of converting sunlight into electrical energy. That is, the area from the first through hole TH1 to the third through hole TH3 is an inactive region NAR.

In this case, an area of the inactive region NAR may be reduced by the first insulating member 810 and the second insulating member 820. That is, the solar cell apparatus according to the embodiment increases the area of the active region AR for converting sunlight into electrical energy and has improved efficiency.

2 to 8 are cross-sectional views illustrating a method of manufacturing the solar cell apparatus according to the embodiment. In the present embodiment, referring to the above-described embodiment, the description of the above-described photovoltaic device may be combined with the description of the manufacturing method of the present embodiment.

Referring to FIG. 2, the back electrode layer 200 is formed on the support substrate 100, and the back electrode layer 200 is patterned to form a first through hole TH1. Accordingly, a plurality of back electrodes 210, 220... Are formed on the substrate. The back electrode layer 200 is patterned by a laser.

The first through hole TH1 exposes an upper surface of the support substrate 100 and has a width of about 10 nm to about 70 nm.

In addition, an additional layer, such as a diffusion barrier, may be interposed between the support substrate 100 and the back electrode layer 200, wherein the first through hole TH1 exposes an upper surface of the additional layer.

Referring to FIG. 3, first insulating members 810 are formed between the back electrodes 210, 220. The first insulating members 810 may be formed by, for example.

In order to form the first insulating members 810, a thermosetting resin composition is injected into the first through hole TH1. The thermosetting resin composition may include a monomer for forming a thermosetting resin. For example, the thermosetting resin composition may include monomers such as bisphenol A, an imide monomer, terephthalic acid, ethylene glycol, ethylene, and vinyl acetate to form EVA, PET, PC, or PI. In addition, the resin composition may further include a thermosetting initiator.

The thermosetting resin composition may have a low viscosity. In addition, the first through hole TH1 may have a shape extending in length.

When the thermosetting resin composition is injected into a part of the first through hole TH1 extending long, the thermosetting resin composition may be injected into the entire inside of the first through hole TH1 by capillary action. In addition, the thermosetting resin composition may be injected by an ink jet method.

A process of removing the unnecessary thermosetting resin composition disposed on the back electrode layer 200 which is an area other than the inside of the first through hole TH1 may be further performed.

Thereafter, the thermosetting resin composition injected into the first through hole TH1 is thermally cured in an additional heat treatment process or a subsequent high temperature deposition process, and the first insulating members 810 are formed.

Referring to FIG. 4, the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 are sequentially formed on the back electrode layer 200.

The light absorbing layer 300 may be formed by a sputtering process or an evaporation method.

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

When the metal precursor film is formed and selenization is subdivided, 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 copper-indium-gallium-selenide-based (Cu (In, Ga) Se ₂ ; CIGS-based) light absorbing layer by a selenization process.

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

Alternatively, the CIS-based or CIG-based light absorbing layer 300 may 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, cadmium sulfide is deposited on the light absorbing layer 300 by a sputtering process, and the buffer layer 400 is formed.

Thereafter, 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. 5, a portion of the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500 is removed to form a second through hole TH2. The second through hole TH2 penetrates the light absorbing layer 300, the buffer layer 400, and the high resistance buffer layer 500.

The second through hole TH2 is formed adjacent to the first through hole TH1. The second through hole TH2 may be formed by a mechanical device such as a tip or a laser device.

For example, the light absorbing layer 300 may be patterned by a tip having a width of about 50 μm to about 110 μm. In addition, the second through hole 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 hole TH2 may be about 100 μm to about 200 μm. In addition, the second through hole TH2 is formed to expose a portion of the top surface of the back electrode layer 200.

Referring to FIG. 6, a window layer 600 is formed on the high resistance buffer layer 500. In this case, a material forming the window layer 600 is filled in the second through hole TH2.

Accordingly, a connection part extending from the window layer 600 and directly connected to the back electrode layer 200 is formed inside the second through hole TH2.

In order to form the window layer 600, a transparent conductive material is stacked on the high resistance buffer layer 500. The transparent conductive material is filled in the entire second through hole TH2. Examples of the transparent conductive material include aluminum doped zinc oxide and the like.

Referring to FIG. 7, a portion of the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the window layer 600 is removed to form a third through hole TH3. That is, the light absorbing layer 300, the buffer layer 400, the high resistance buffer layer 500, and the window layer 600 are patterned to define a plurality of windows 610, 620...

The third through hole TH3 exposes an upper surface of the back electrode layer 200.

The third through hole TH3 may be formed by a mechanical device such as a tip or a laser device.

For example, by the tip, the window layer 600 may be patterned. In addition, the third through hole TH3 may be formed by a laser having a wavelength of about 200 to 600 nm.

The width of the third through hole TH3 may be about 10 μm to about 100 μm.

By the second through hole TH2 and the third through hole TH3, the light absorbing layer 300 is divided into a plurality of light absorbing parts 310, 320.

In addition, a plurality of cells C1, C2... Are defined by the third through hole TH3.

Referring to FIG. 8, second insulating members 820 are formed inside the third through hole TH3. The second insulating members 820 are filled with an insulating material inside the third through hole TH3, and the second insulating members 820 are formed.

In order to form the second insulating members 820, a thermosetting resin composition is injected into the third through hole TH3. The thermosetting resin composition may include a monomer for forming a thermosetting resin. For example, the thermosetting resin composition may include monomers such as bisphenol A, an imide monomer, terephthalic acid, ethylene glycol, ethylene, and vinyl acetate to form EVA, PET, PC, or PI. In addition, the resin composition may further include a thermosetting initiator.

The thermosetting resin composition may have a low viscosity. In addition, the third through hole TH3 may have a shape extending in length.

When the thermosetting resin composition is injected into a portion of the third through hole TH3 extending long, the thermosetting resin composition may be injected into the entire inside of the third through hole TH3 by capillary action. In addition, the thermosetting resin composition may be injected by an ink jet method.

A process of removing the unnecessary thermosetting resin composition disposed on the window layer 600 which is an area other than the inside of the third through hole TH3 may be further performed.

Thereafter, the thermosetting resin composition injected into the third through hole TH3 is thermally cured in an additional heat treatment process or a subsequent high temperature laminating process, and the second insulating members 820 are formed.

As a result, a photovoltaic device that prevents short between the cells C1, C2... And has improved efficiency may be provided.

Although described above with reference to the embodiment is only an example and is not intended to limit the invention, those of ordinary skill in the art to which the present invention does not exemplify the above within the scope not departing from the essential characteristics of this embodiment It will be appreciated that many variations and applications are possible. For example, each component specifically shown in the embodiment can be modified. And differences relating to such modifications and applications will have to be construed as being included in the scope of the invention defined in the appended claims.

1 is a cross-sectional view showing a cross section of the solar cell apparatus according to the embodiment.

2 to 8 are cross-sectional views illustrating a method of manufacturing the solar cell apparatus according to the embodiment.

Claims (9)

Board; A plurality of electrodes disposed on the substrate and spaced apart from each other; A plurality of first insulating members interposed between the electrodes; A plurality of light absorbing parts disposed on the electrodes; And A photovoltaic device comprising a plurality of windows disposed on the light absorbing portions. The solar cell apparatus according to claim 1, further comprising a plurality of second insulating members interposed between the windows. The solar cell apparatus of claim 2, wherein the second insulating members are interposed between the light absorbing portions. The solar cell apparatus of claim 2, wherein the second insulating members include ethylene vinyl acetate, polyethylene terephthalate, polycarbonate, or polyimide. The solar cell apparatus of claim 1, wherein the first insulating members include ethylene vinyl acetate, polyethylene terephthalate, or polycarbonate. The solar cell apparatus of claim 1, wherein an upper surface of the first insulating members and an upper surface of the electrodes are disposed on the same plane. Forming a plurality of electrodes on the substrate; Forming a plurality of first insulating members between the electrodes, respectively; Forming light absorbing portions on the electrodes; And A method of manufacturing a photovoltaic device comprising forming windows on the light absorbing portions. The method of claim 7, wherein the forming of the first insulating members Disposing a resin composition between the electrodes; And Method of manufacturing a photovoltaic device comprising the step of curing the resin composition. 8. The method of claim 7, further comprising: disposing a resin composition between the windows; And Curing the resin composition to form second insulating members between the windows, respectively.

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