KR101459279B1 - Fabrication Method for Flexible Solor Cell with Flexible Substrate. - Google Patents

Abstract

The present invention relates to a method of manufacturing a solar cell having a flexible substrate, in which a separating layer is formed on a mother substrate such as a glass substrate, a flexible substrate is formed thereon, a solar cell is manufactured, A method for manufacturing a solar cell having a flexible substrate that can simplify the process and increase the mass productivity at low cost, including a step of separating and removing the mother substrate.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a manufacturing method of a flexible substrate,

The present invention relates to a method of manufacturing a CIGS solar cell having a flexible substrate.

Solar cell is a device that converts light energy into electrical energy using the properties of semiconductor. A solar cell has a PN junction structure in which a positive (P) type semiconductor and a negative (N) type semiconductor are bonded to each other. When solar light is incident on such a solar cell, Holes and electrons are generated. At this time, the holes move toward the P-type semiconductor due to the electric field generated at the PN junction, and the electrons move toward the N-type semiconductor, and a potential is generated.

Solar cells can be broadly divided into substrate-type solar cells and thin-film solar cells. A substrate type solar cell is a solar cell using a semiconductor material itself such as silicon as a substrate, and a thin film type solar cell is a solar cell by forming a semiconductor layer in the form of a thin film on a substrate such as glass. In recent years, semiconductor compounds represented by CuInSe2 have emerged as new high-efficiency solar cell materials that can replace crystalline silicon solar cells currently in use. Here, a thin film solar cell including a semiconductor compound of CuInSe2 is referred to as a CuInSe2 thin film solar cell. And CuInSe2 has a chalcopyrite structure. The CuInSe2 thin film solar cell has a band gap of 1.04 eV, which is smaller than 1.4 eV, which is an ideal bandgap for solar absorption. In order to widen the bandgap of the CuInSe2 thin film solar cell, a part of In contained in CuInSe2 is replaced with Ga, and a part of Se is replaced with S. As described above, a siliceous compound in which a part of the constituent elements are substituted is referred to as a CIGS material.

Lightweight and flexible solar cells have attracted attention as one of important technologies for promoting and promoting solar power generation by enabling installation in a place where introduction of solar cells has been difficult. Conventional flexible solar cells have advantages in terms of light and bendable functions, but they are disadvantageous in performance. However, recent technology has succeeded in high performance, but problems such as low cost, large size, and mass production remain.

Korean Patent Registration No. 10-0847741 relates to a point-contact heterogeneous silicon solar cell having a passivation layer on a p-n junction interface and a method of manufacturing the same, and by minimizing the contact area between amorphous / crystalline silicon, And a heterojunction silicon solar cell capable of exhibiting an increase in the filling factor of the solar cell and an improved efficiency by improving the characteristics of the pn diode through a minimum point contact or a partial surface contact is provided. The heterojunction silicon solar cell according to the present invention is characterized in that a second type amorphous silicon layer is formed on a first type crystalline silicon wafer and a transparent conductive film and an upper electrode are formed on the second type amorphous silicon layer, And a lower electrode is formed on the lower surface of the first type silicon wafer. In the hetero-junction silicon solar cell, a plurality of voids penetrating the front and back surfaces of the first type crystalline silicon wafer and the second type amorphous silicon layer are formed And a passivation layer is inserted to allow the first type silicon wafer and the second type silicon layer to contact only through the gap. A method for producing the heterojunction silicon solar cell is also provided. According to the heterojunction silicon solar cell, the interface area between amorphous / crystalline silicon can be minimized to reduce interface defects and the solar cell filling rate can be increased by improving the characteristics of the pn diode through a minimum point contact or a partial surface contact have. However, silicon solar cells are limited in their flexibility.

Soda ash glass is most commonly used for substrates, and various other types of substrate materials are used for cost reduction and diversification of applications, and also flexible substrates such as stainless steel, titanium, and polymers are used. Development of CIGS solar cell Corning glass was used as a substrate in order to apply a high process temperature. However, researches have been carried out to replace the glass with soda ash glass in order to reduce the cost of the substrate. In the process, CIGS solar cell using soda ash glass was found to be significantly improved in properties compared with the non - soda ash glass, and it is known that sodium is diffused into CIGS light absorption layer in soda ash glass.

In the case of using a substrate as a glass substrate, particularly a soda ash glass, there is an advantage such as a reduction in the cost of the substrate and an improvement in the characteristics of the CIGS light absorbing layer. However, there are disadvantages in manufacturing a flexible solar cell and other flexible substrates There is an attempt. Thus, lightweight and flexible solar cells are attracting attention as one of important technologies for promoting and promoting solar power generation by enabling installation in a place where introduction of solar cells has been difficult. Conventional flexible solar cells have advantages in terms of light and bendable functions, but they are disadvantageous in performance. However, the latest technology has succeeded in high performance, but the problem of low cost, large size, and mass productivity remains.

In order to solve the above-described problems, the present invention provides a method of manufacturing a semiconductor device, comprising: forming a separation layer on a mother substrate using a glass substrate as a mother substrate; forming a flexible substrate layer such as polyimide on the separation layer; After the absorption layer, the buffer layer, and the front electrode are formed in order, the separation layer is irradiated with a laser to separate the mother substrate, thereby solving the problem of cost and mass productivity.

A CIGS solar cell formed of a flexible substrate is light and flexible, which makes it possible to install a solar cell even in a place where it was difficult to introduce, and after manufacturing a solar cell on a glass substrate, a laser is irradiated to separate and remove the glass substrate The process is simple, the cost can be reduced, and the mass productivity is improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart showing a step-by-step process for producing a solar cell having a flexible substrate according to the present invention.
FIG. 2 is a flowchart showing a step-by-step process for producing a solar cell having a flexible substrate according to the present invention.
3 is a configuration diagram showing the principle of separating the mother substrate by irradiating the separation layer with a laser.
4 is a configuration diagram of a solar cell manufactured by the manufacturing method of the present invention.

A manufacturing method of a solar cell having a flexible substrate according to the present invention and a solar cell manufactured by the manufacturing method will be described with reference to the accompanying drawings.

FIG. 1 is a flowchart showing a method of manufacturing a solar cell having a flexible substrate according to the present invention. FIG. 1 is a diagram illustrating a method of manufacturing a solar cell having a flexible substrate. Forming an isolation layer on the mother substrate; Forming a flexible substrate on the isolation layer; Forming a back electrode layer on the flexible substrate; Forming a CIGS light absorbing layer on the rear electrode layer; Forming a buffer layer on the CIGS light absorption layer; Forming a front electrode layer on the buffer layer; And separating the mother substrate by irradiating the separation layer with a laser.

FIG. 2 is a flowchart illustrating a method of manufacturing a solar cell having a flexible substrate according to the present invention. FIG. 2 is a flowchart illustrating a method of manufacturing a solar cell having a flexible substrate. Forming an isolation layer on the mother substrate; Forming a flexible substrate on the isolation layer; Irradiating the separation layer with a laser to separate the mother substrate; Forming a back electrode layer on the separated surface of the flexible substrate; Forming a CIGS light absorbing layer on the rear electrode layer; Forming a buffer layer on the CIGS light absorption layer; And forming a front electrode layer on the buffer layer.

As the matrix substrate, either a glass substrate or a quartz substrate can be used.

The separation layer may be formed of amorphous silicon (a-Si: H) containing hydrogen, amorphous silicon sodium (a-SiNx: H) containing hydrogen, amorphous silicon oxide containing hydrogen And can be configured to include any one of them. The separation layer may be formed to a thickness of 10 nm to 2 탆 by at least one of chemical vapor deposition, sputtering, ion plating, spin coating, spray coating, transferring, arc jetting and powder jetting.

The flexible substrate may be formed by (a) depositing a polyimide-forming monomer on the separation layer by any one of a thermal deposition method, a plasma chemical vapor deposition method, an atomic layer deposition method, a spin coating method, a doctor blade method, ; And heat treating the deposited monomers to form a polyimide layer. The polyimide-forming monomer comprises at least one acid component selected from the group consisting of perylenetetracarboxylic dianhydride (PTCDA), biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), diaminododecane (DADD), oxydianiline (ODA), and phenylene diamine Lt; RTI ID = 0.0 > 1, < / RTI > The heat treatment of the deposited monomers can be performed at 100 to 350 ° C.

The rear electrode is at least one of nickel, copper, and molybdenum, and can be formed by any one of a sputtering method, a thermal evaporation method, and an electron beam evaporation method. The thickness of the rear electrode may be 100 nm to 10 μm, but the present invention is not limited thereto.

The CIGS light absorbing layer can be formed by any one of the following methods: simultaneous evaporation using copper, indium, gallium, and cerium, or selenization or sulfurization of a precursor film of copper, indium, gallium, and cerium have.

The buffer layer may include at least one of cadmium sulfide and zinc sulfide and may be formed by any one of chemical vapor deposition (CBD), electrodeposition, co-evaporation, sputtering, atomic layer deposition, atomic layer deposition, , Chemical vapor deposition (MOCVD), or molecular beam growth (MBE).

The front electrode is made of at least one of zinc oxide, gallium oxide, aluminum oxide, indium oxide, lead oxide, copper oxide, titanium oxide, tin oxide, iron oxide, tin dioxide and indium tin oxide and is formed by sputtering, Method, and an organometallic chemical vapor deposition method.

3 is a configuration diagram showing the principle of separating the mother substrate by irradiating the separation layer with a laser. The laser can be any one of XeCl, ArF, KrCl, KrF, XeCl, and XeF lasers, and irradiates the separation layer with the laser from the bottom surface of the mother substrate. (A-Si: H) containing hydrogen, amorphous silicon containing hydrogen (a-SiNx: H) and amorphous silicon oxide containing hydrogen (a-SiOx: H) In either case, the laser is irradiated to dissolve the separation layer and release hydrogen, thereby separating the mother substrate from the flexible substrate.

FIG. 4 is a view illustrating the structure of a solar cell manufactured by the manufacturing method of the present invention. A solar cell having a flexible substrate includes a flexible substrate including polyimide; A rear electrode comprising at least one of nickel, copper, and molybdenum formed on the flexible substrate; A CIGS light absorbing layer formed on the rear electrode; A buffer layer comprising at least one of cadmium sulfide and zinc sulfide formed on the CIGS light absorption layer; And a front electrode comprising at least one of zinc oxide, gallium oxide, aluminum oxide, indium oxide, lead oxide, copper oxide, titanium oxide, tin oxide, iron oxide, tin dioxide and indium tin oxide formed on the buffer layer do.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it should be understood that various changes and modifications will be apparent to those skilled in the art. Obviously, the invention is not limited to the embodiments described above. Accordingly, the scope of protection of the present invention should be construed according to the following claims, and all technical ideas which fall within the scope of equivalence by alteration, substitution, substitution, Range. In addition, it should be clarified that some configurations of the drawings are intended to explain the configuration more clearly and are provided in an exaggerated or reduced size than the actual configuration.

100: mother substrate 150: separation layer
200: Flexible substrate 300: Rear electrode layer
400: light absorbing layer 500: buffer layer
600: front electrode layer

Claims (15)

delete A method of manufacturing a solar cell having a flexible substrate,
(i) preparing a matrix substrate;
(ii) forming a separation layer on the mother substrate;
(iii) forming a flexible substrate on the isolation layer;
(iv) separating the mother substrate by irradiating the separation layer with a laser;
(v) forming a rear electrode layer on the separated surface of the flexible substrate;
(vi) forming a CIGS light absorbing layer on the rear electrode layer;
(vii) forming a buffer layer on the CIGS light absorption layer;
(viii) forming a front electrode layer on the buffer layer;
And a second electrode formed on the second electrode.
3. The method of claim 2,
Wherein the mother substrate in the step (i) is one of a glass substrate and a quartz substrate.
3. The method of claim 2,
The separation layer in the step (ii) may be selected from the group consisting of amorphous silicon (a-Si), amorphous silicon containing hydrogen (a-Si: H), amorphous silicon containing hydrogen (a- Wherein the amorphous silicon oxide (a-SiOx: H) is one of amorphous silicon oxide (a-SiOx: H)
3. The method of claim 2,
The separation layer in the step (ii) may be formed by at least one of chemical vapor deposition, sputtering, ion plating, spin coating, spray coating, transferring, arc jetting and powder jetting to a thickness of 10 nm to 2 탆 Wherein the first electrode and the second electrode are formed of a metal.
3. The method of claim 2,
The formation of the flexible substrate in step (iii)
(a) depositing a polyimide-forming monomer on the separation layer by any one of a thermal deposition method, a plasma chemical vapor deposition method, an atomic layer deposition method, a spin coating method, a doctor blade method, a printing method and an inkjet coating method;
(b) heat treating the deposited monomers to form a polyimide layer;
And a second electrode formed on the second electrode.
The method according to claim 6,
The polyimide-forming monomer may be at least one acid component selected from the group consisting of perylene tetracarboxylic dianhydride (PTCDA), biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), diaminododecane (DADD), oxydianiline (ODA), and phenylene diamine ≪ / RTI > and at least one amine component selected from the group consisting of: < RTI ID = 0.0 >
The method according to claim 6,
Wherein the heat treatment of the deposited monomers is performed at 100 to 350 ° C.
3. The method of claim 2,
Wherein the rear electrode is at least one of nickel, copper, and molybdenum,
A sputtering method, a thermal evaporation method, an electron beam evaporation method, and an electrodeposition method.
3. The method of claim 2,
The CIGS light absorption layer may be formed by any one of the simultaneous evaporation method using copper, indium, gallium, and cerium, or the method of performing a selenization or sulfurization process on precursor films of copper, indium, gallium, and cerium ≪ / RTI >
3. The method of claim 2,
Wherein the buffer layer comprises at least one of cadmium sulfide and zinc sulfide,
(CVD), metalorganic chemical vapor deposition (MOCVD), or molecular beam growth (MBE), at least one of the following methods: chemical solution growth method (CBD), electrodeposition method, co-evaporation method, sputtering method, atomic layer growth method, atomic layer deposition method, chemical vapor deposition method And the second electrode is formed by any one of the methods.
3. The method of claim 2,
Wherein the front electrode comprises at least one of zinc oxide, gallium oxide, aluminum oxide, indium oxide, lead oxide, copper oxide, titanium oxide, tin oxide, iron oxide, tin dioxide and indium tin oxide,
A sputtering method, a thermal evaporation method, and an organic metal chemical vapor deposition method.
3. The method of claim 2,
The laser is any one of XeCL, ArF, KrCl, KrF, XeCl, and XeF lasers,
Wherein the laser is irradiated from a lower surface of the mother substrate.
3. The method of claim 2,
(A-Si: H) containing hydrogen, amorphous silicon sodium (a-SiNx: H) containing hydrogen, amorphous silicon oxide containing hydrogen (a-SiOx: H) In the case of any one of them,
Wherein the separation layer is dissolved and the hydrogen is released by irradiating the separation layer with a laser, so that the mother substrate is separated from the flexible substrate.
A process for producing a polyurethane foam, comprising the steps of:
A flexible substrate comprising polyimide;
A rear electrode comprising at least one of nickel, copper, and molybdenum formed on the flexible substrate;
A CIGS light absorbing layer formed on the rear electrode;
A buffer layer comprising at least one of cadmium sulfide and zinc sulfide formed on the CIGS light absorption layer;
A front electrode comprising at least one of zinc oxide, gallium oxide, aluminum oxide, indium oxide, lead oxide, copper oxide, titanium oxide, tin oxide, iron oxide, tin dioxide and indium tin oxide formed on the buffer layer;
And a second electrode connected to the second electrode.

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