KR20130063147A - Method of manufacturing fe-ni alloy substrate for ci(g)s solar cell - Google Patents

Abstract

PURPOSE: A method for manufacturing an iron-nickel alloy substrate for CI(G)S solar cell is provided to use a horizontal electroforming method, thereby continuously manufacturing a thin substrate for the solar cell. CONSTITUTION: A method for manufacturing an iron-nickel alloy substrate for CI(G)S solar cell includes: a step of feeding an electrolyte between a conductive substrate(11) and an anode electrode(32); a step of applying a current to the conductive substrate and the anode electrode at the conductive substrate in order to electrodeposit iron and nickel, which are included in the electrolyte, on the conductive substrate; a step of separating an iron-nickel alloy electrodepositing layer, which is formed by electrodepositing the iron and the nickel, from the conductive substrate in order to obtain an iron-nickel alloy foil(50); and a step of forming at least one diffusion-proof film of a metal, which is selected from a group of chrome and a nickel, on the electrodepositing surface of the foil. The electrolyte includes 2 to 25 g/L of an iron precursor and 40 to 60 g/L of a nickel precursor.

Description

Method of manufacturing iron-nickel alloy substrate for CIS solar cell {METHOD OF MANUFACTURING Fe-Ni ALLOY SUBSTRATE FOR CI (G) S SOLAR CELL}

The present invention relates to a method for manufacturing a Fe-Ni alloy substrate for GI (G) S solar cells by a horizontal electroforming method, and in particular, it is possible to continuously mass-produce a Fe-Ni substrate for a solar cell having a constant surface roughness by a horizontal electroforming method. The present invention relates to a method for producing an Fe-Ni alloy substrate for an economic CI (G) S solar cell.

Traditional methods of collecting energy using fossil fuels are slowly reaching their limits due to global warming, depletion of fuel resources, and environmental pollution. In particular, the outlook is that petroleum fuel will be exhausted in not too long time. In addition, the Energy Climate Convention, represented by the Kyoto Protocol, is compulsoryly required to reduce the emissions of carbon dioxide produced by the burning of fossil fuels. Therefore, the limitation of annual usage of fossil fuel is obvious not only in the present Contracting State but also in the world in the future.

Alternative energy sources for fossil fuels include nuclear power and hydropower. However, nuclear power generation has emerged as a major problem due to the explosion of the former Chernobyl nuclear power plant and Fukushima nuclear power plant caused by the Great East Japan Earthquake. Hydropower is affected by topographic and climatic factors. Its use is limited. In addition, other alternative energy sources are also limited as alternative energy sources that can replace fossil fuels due to low power generation or limited use areas.

However, solar cells can be used anywhere as long as only a reasonable amount of sunlight is ensured, and the power generation capacity and equipment scale are almost linearly proportional to each other. Therefore, when the solar cells are used for small capacity such as home use, the solar cells are installed by installing a small area on the roof of a building. The advantage of this is that not only is its use globally, but its research is also increasing.

The solar cell is based on the principle of a semiconductor. When a light having a predetermined level or more of energy is irradiated to a pn-bonded semiconductor, the solar cell is excited as a home appliance that can move freely and is a pair of electrons and holes (EHP: electron hole pair). ) Is generated. The generated electrons and holes move to the electrode located on the opposite side to generate an electromotive force.

The first form of the solar cell is to form a p-type semiconductor by doping an impurity (B) to a silicon substrate and then doping another impurity (P) thereon to form a n-type semiconductor part of the layer to make a pn junction As a silicon solar cell, it is often called the first generation solar cell.

Since the silicon-based solar cell has a relatively high energy conversion efficiency and cell conversion efficiency (the ratio of the conversion efficiency at the time of mass production to the energy conversion efficiency of the laboratory), the degree of commercialization is the highest. However, in order to manufacture the silicon-based solar cell module, not only has to go through a rather complicated process step of manufacturing an ingot from a material first and then wafering the ingot and then manufacturing and modularizing a cell, but also using a bulk material. There is a problem that the manufacturing cost is high due to increased material consumption.

In addition, the silicon-based solar cell has to be made of a single crystal or polycrystal of the crystalline form of silicon, there is a disadvantage that not only complicated manufacturing process is required to manufacture silicon having a single crystal or polycrystal, but also the manufacturing cost increases.

In order to solve the drawbacks of such silicon-based solar cells, so-called thin film solar cells called second generation solar cells have been proposed. The thin film type solar cell is not manufactured as a solar cell by the above-described process, but instead of a silicon wafer, the thin film type solar cell is manufactured by sequentially stacking the thin film layers on the substrate. Therefore, the thin film type solar cell is simple, thin and low in manufacturing cost. Have

One of them is a CI (G) S compound semiconductor containing copper (Cu), indium (In), germanium (Ge) and selenium (Se), which may not contain germanium, in this case called CIS. CI (G) S based solar cell based on CI (G) S, but also referred to as CIGS and used here as a concept that includes both cases). Sometimes selenium (Se) is replaced with sulfur (S) or selenium may be used together with sulfur. In the present invention, all of them are regarded as the CI (G) S solar cell.

Since the CI (G) S compound semiconductor contains 3 or 4 elements, the width of the band can be controlled by adjusting the content of the element, thereby increasing the energy conversion efficiency.

In the laminated structure of a GI (G) S solar cell, a substrate is usually present on the bottom layer and a back metal layer used as an electrode is formed on the substrate. On the back metal layer, a light absorbing layer (CI (G) S) as a p-type semiconductor and a buffer layer (eg, CdS) for reducing the bandgap energy of the light absorbing layer and the transparent window, a transparent window as an n-type semiconductor, and a front metal layer ( Electrodes) are formed sequentially.

The CI (G) S-based solar cell should have the same thermal expansion coefficient of the stacked materials in order to ensure durability. If a variation in the coefficient of thermal expansion occurs between the solar cell substrate and the material stacked on the substrate, stress may be applied to the substrate or the material stacked thereon as the temperature increases or decreases, thereby shrinking or expanding. Because of this, cracks or breaks may occur, so the solar electrical components need to be controlled to a nearly similar level of coefficient of thermal expansion.

On the other hand, as a material used as the substrate has been used a lot of glass in general, the glass substrate is relatively expensive, has the disadvantage that it is not suitable for mass production, can be used only in a standardized form. In addition, the thin film, which is a characteristic of CI (G) S-based solar cells, has a problem.

An embodiment of the present invention is to reduce the manufacturing cost by manufacturing a substrate by a horizontal cell type electroforming method, and the CI (G) S solar cell substrate having flexibility and durability that is easy to thin film and mass production and its To provide a manufacturing method.

Another embodiment of the present invention is to provide a Fe-Ni alloy substrate manufacturing method for CI (G) S solar cells with an optimized thermal expansion coefficient.

Another embodiment of the present invention is to provide a Fe-Ni alloy substrate manufacturing method for CI (G) S solar cells excellent in strength, hardness, corrosion resistance and / or durability.

Furthermore, the present invention provides a method for producing a Fe-Ni alloy substrate for a CI (G) S solar cell having a continuous process and excellent productivity.

Yet another embodiment of the present invention is to provide a method for manufacturing a Fe-Ni alloy substrate for CI (G) S solar cells of a flexible thin film.

The present invention relates to a method for manufacturing an alloy substrate for CIGS solar cells, according to an embodiment of the present invention, between a conductive base plate horizontally supplied in a predetermined direction and an anode electrode spaced apart from one side or both sides of the conductive base plate Supplying an electrolyte solution, wherein the electrolyte solution includes an electrolyte solution supplying step including 2-25 g / L iron precursor and 40-60 g / L nickel precursor; Applying a current to the conductive base plate and an anode electrode disposed on one or both surfaces of the conductive base plate to apply the current to electrodeposit the iron and nickel contained in the electrolyte on one or both sides of the conductive base plate; A peeling step of separating an alloy electrodeposition layer of iron and nickel formed by electrodeposition of iron and nickel from the conductive mother plate to obtain an alloy foil of iron and nickel; And a diffusion barrier layer forming step of forming a diffusion barrier of at least one metal selected from the group consisting of chromium and nickel on the electrodeposited surface of the alloy foil of iron and nickel.

According to another embodiment, the diffusion barrier may have a thickness of 100-500nm.

According to another embodiment, the iron precursor is at least one selected from the group consisting of iron sulfate, iron chloride, iron nitrate, and iron sulfamate, and the nickel precursor comprises nickel sulfate, nickel chloride, nickel nitrate, and nickel sulfamate. It can be selected from the group.

In another embodiment, the electrolyte may further include 0.1-8.0 g / L of surfactant which is polyethylene glycol, sodium laureth sulfate or a mixture thereof.

Furthermore, according to one embodiment of the present invention, the Fe-Ni alloy substrate for solar cells may have a surface roughness (Rz) of the surface on which the diffusion barrier is formed is 0.1 to 100nm.

And, according to another embodiment of the present invention, the Fe-Ni alloy substrate Fe-Ni alloy substrate manufacturing method for CI (G) S solar cell, characterized in that the thickness of 20-70㎛.

According to another embodiment of the present invention, the Fe-Ni alloy substrate may be composed of 28 to 32% by weight or 45 to 75% by weight of nickel and the balance iron and other unavoidable impurities.

The planarization film forming step of forming a planarization film of a polymer resin selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester and polyimide may be further included on the diffusion barrier.

In addition, the electrolyte supply step and the current application step may be performed a plurality of times.

According to one embodiment of the present invention, by manufacturing the substrate for the CI (G) S solar cell by a horizontal cell type electroforming method, it is possible to mass-produce, thereby reducing the cost of manufacturing the substrate, and also to control the content of nickel As a result, the thermal expansion coefficient of the substrate can be optimized.

According to another embodiment of the present invention, an Fe-Ni alloy substrate for CI (G) S solar cells having excellent strength, hardness, corrosion resistance, and / or durability can be obtained.

Furthermore, the present invention can manufacture a Fe-Ni alloy substrate for CI (G) S solar cells having a continuous process and excellent productivity.

And it is possible to prevent the iron of the substrate from diffusing into the metal layer formed on the substrate.

1 is a view schematically showing an example of the configuration of a horizontal electric casting apparatus used in the manufacture of Fe-Ni alloy substrate for CI (G) S solar cell according to an embodiment of the present invention.

The present invention relates to a method for producing a Fe-Ni alloy substrate for CIGS solar cells by horizontal electroforming.

In case of manufacturing a substrate for CI (G) S solar cell by conventional rolling method, it is required to go through several heat treatment and rolling processes in order to reduce the thickness of the substrate. There is a problem of cost and time, and it is difficult to maintain a constant shape. In addition, thickness variations occur, surface roughness is not constant, and problems such as edge cracks are generated, resulting in high manufacturing costs and difficulty in manufacturing a wide metal electrodeposition layer. Furthermore, in order to use the CIGS solar cell substrate, it is necessary to manage the surface roughness of the substrate. When manufacturing the substrate by the rolling method, it is difficult to control the surface roughness because the inclusions are distributed in the surface layer.

On the other hand, in the case of manufacturing a metal electrodeposition layer by the electroforming method using a drum cell, it is important to manage the surface of the drum in order to produce a thin film having a uniform thickness and surface shape, this is a problem that must stop the operation of the entire process It is difficult to manage the drum surface continuously.

In addition, with respect to thin film production, the area of the drum surface immersed in the electrolyte determines the deposition rate, so the production speed is limited according to the size of the drum used in the pole and the cost of providing a large drum is high. The disadvantage is that there is a limit to the replacement. Furthermore, in order to increase the production rate, the flow rate of the electrolyte solution between the anode and the cathode must be increased, but there is a problem that the flow rate of the electrolyte solution gradually decreases because the shape between the anode and the cathode is composed of curvature.

However, in one embodiment of the present invention, by using a horizontal electroforming method, an alloy of an iron and nickel (hereinafter, also referred to as a 'Fe-Ni alloy') substrate of a thin film of CI (G) S solar cell may be continuously manufactured. . In addition, not only an alloy electrodeposition layer of iron and nickel can be formed on both sides of the mother plate at the same time, but also a high speed flow field through which the electrolyte is supplied at high speed can be used, thereby improving productivity.

According to an embodiment of the present invention, a method of manufacturing a Fe-Ni alloy substrate for a CI (G) S solar cell by horizontal electroforming includes supplying an electrolyte solution to a conductive base plate which is horizontally supplied in a predetermined direction, and the iron on the surface of the conductive mother plate. Applying a current so that the nickel is electrodeposited, separating the Fe-Ni alloy electrodeposition layer formed by electrodepositing iron and nickel to obtain a Fe-Ni alloy foil.

In forming the Fe-Ni alloy substrate for solar cells by horizontal electroforming, any substrate having flexibility and conductivity may be used as the substrate without particular limitation. It is preferable that an oxide film, specifically a metal oxide film, is formed on the surface of such a mother plate. Although not limited to this as a metal oxide film, titanium oxide, chromium oxide, lithium oxide, an iridium oxide, a platinum oxide, etc. can be formed. Specifically, for example, a metal substrate such as stainless steel or titanium in which the metal oxide film is formed may be used.

Also, for example, plastic substrates having conductivity and flexibility can be used. Specifically, the conductivity and flexibility for plastic substrates can be imparted by generally known methods of forming metal oxides and / or metal layers. For example, a plastic substrate on which the metal oxide film and / or platinum layer described above is formed may be used.

When the Fe—Ni alloy electrodeposition layer formed by electrodeposition on the mother plate surface has a firm bond with the mother plate, it is not easy to separate the Fe—Ni alloy electrodeposition layer from the mother plate, so that an oxide film is preferably formed on the mother plate surface. . Even if the Fe—Ni alloy electrodeposition layer is electrodeposited on the surface of the mother plate due to the oxide film on the surface of the mother plate, since the adhesion to the surface of the mother plate is weak, the Fe—Ni alloy electrodeposition layer can be easily peeled from the mother plate.

If necessary, the surface roughness of the mother plate may be controlled. As such, the surface of the mother plate may be further subjected to the step of polishing the surface of the mother plate to control the surface roughness. In the production of Fe-Ni alloy foil by electroforming, the quality of Fe-Ni alloy foil tends to be largely influenced by the surface roughness. For example, the electrodeposition layer electrodeposited on the base plate transfers the surface roughness of the base plate, and the Fe-Ni alloy foil obtained by transferring the portion having the poor surface roughness of the base plate is used for electrical shorts and electrical and / or device materials. There is a risk of failure. Furthermore, the CI (G) S solar cell substrate of the present invention includes an intention to replace the glass substrate used in the prior art, but when the surface roughness is rough, the same effect as the glass substrate cannot be obtained.

Therefore, it is desirable to appropriately control the surface roughness of the base plate, for example, to evenly and comfortably have a surface roughness of 100 nm or less, more preferably 30 nm or less, even more preferably 10 nm or less. It is desirable to maintain.

Thus, in order to give the surface roughness of the said base plate, grinding | polishing can be performed to one side or both surfaces of a base plate as needed. Polishing for imparting surface roughness may be applied to any suitable mechanical, chemical or mechanical chemical polishing means known in the art. For example, mechanical polishing, such as polishing, chemical polishing, such as etching, mechanical chemical polishing, such as the CMP method mainly used in a semiconductor process, etc. are mentioned.

Furthermore, the mother plate may further include a mother plate washing step for removing impurities, etc. on the surface of the mother plate as needed before the electrodeposition process. The mother-plate washing is not particularly limited and can be carried out by a method generally known in the art. Although not limited to this, it can wash | clean, for example using acidic solution and water. The acidic solution can be any acidic solution generally known for use in substrate cleaning. Thereafter, high pressure air, hot gas may be injected or the base plate may be heated to further dry as necessary.

Such base plates are continuously supplied into the horizontal electroforming cell and are supplied in a constant direction. Herein, the 'electro casting cell' is a reaction in which an electrolytic solution is supplied onto a mother plate, and metal ions, specifically, iron ions are electrodeposited on the surface of the mother plate where a flow path shape is formed by an electrolytic precipitation reaction to form a Fe-Ni alloy electrodeposition layer. This can be defined as the unit cell in which it occurs. In addition, after the mother plate is supplied into the electroforming cell, the 'uniform direction' means that the traveling direction of the mother plate does not change until at least one exits the horizontal cell, and thus, the mother plate proceeds in one direction. In this specification, the advancing direction of the mother plate may be referred to as 'horizontal direction' or simply 'horizontal' in some cases, and furthermore, the mother plate advances the electroforming cell in the horizontal direction so that the metal ions (iron ions and nickel) in the electrolyte The electroforming cell is also referred to as a 'horizontal cell' to indicate that ions) are electrolytically deposited on the mother plate.

For the continuous supply of the base plate, the base plate is not limited thereto, but the base plate wound in the form of a coil can be supplied into the horizontal cell. Furthermore, when all of the base plate is supplied, the base plate is wound in the form of another coil. Subsequent to the supplied base plate can be fed continuously. At this time, if necessary, the rear end of the preceding base plate and the leading end of the following base plate can be joined by a predetermined bonding method such as welding and continuously supplied. Furthermore, in order to easily join, each terminal joined can also be processed to a suitable shape.

The base plate may be supplied horizontally into the horizontal cell by a pair of conductor rolls which contact the width edge of the base plate to transfer the base plate into the horizontal cell. At this time, the electrolytic solution may be supplied to one side of the mother plate supplied into the horizontal cell to perform electroforming on one side, and the electrolytic solution may be supplied to both sides to electrolytically deposit iron and nickel on both sides to deposit the Fe-Ni alloy. Can increase the production speed.

When the mother plate is supplied into the horizontal cell as described above, the electrolyte is supplied to one side or both sides of the mother plate through the electrolyte supply nozzle, and the electrolyte moves through the horizontal flow path formed by the mother plate and the anode electrode, and thus the cathode of the cathode is applied. Electrolytic precipitation by the action of the mother plate and the anode electrode, which plays a role, precipitates iron and nickel ions on the surface of the mother plate to form an Fe-Ni alloy electrodeposition layer.

In the case of the conventional drum-type cell, the base plate shape provided as the cathode has a curvature in a drum shape, so that the flow path of the electrolyte also forms a curvature, which causes the flow rate of the electrolyte to gradually decrease, resulting in a decrease in electrodeposition rate, and the resulting metal. There is a problem that the thickness of the electrodeposition layer becomes uneven. Furthermore, in the case where the oxide film is formed on the drum surface, impurities are introduced into the electrolyte during this process, and thus there is a problem that the management of the electrolyte is not easy.

However, in the case of the horizontal cell, since the electrolyte flow path is formed horizontally, the electrolyte can be supplied at high speed without decreasing the flow rate of the electrolyte, thereby increasing the electrodeposition rate of the iron ions. The supply rate of electrolyte (Re, Reynolds number) can be supplied up to 5,000, and the relative speed can be appropriately increased or decreased depending on the progress of the mother plate. In addition, depending on the state of the electrodeposition reaction, the electrolyte may be supplied at a flow rate of laminar flow (the flow of fluid supplied in a straight line without shaking the water, having straightness), and a high speed turbulence (water stem) after a stable electrodeposition reaction is formed. Can be supplied at a flow rate).

If the flow rate of electrolyte is increased during initial electrodeposition, electrodeposition layer may be separated and electrodeposition may fail. If electrodeposition layer grows to several micro level, adhesion is improved by stress generated in electrodeposited layer and high speed flow field can be used. It is. On the other hand, when using a high speed flow field, the fluid supply speed region is preferably supplied at a flow rate below the surface tension between the electrodeposition layer and the mother plate, and the electrolyte is supplied at a flow rate beyond the surface tension between the electrodeposition layer and the mother plate. When supplied, the shear stress between the flow field and the electrodeposited layer due to the supply of the electrolyte exceeds the surface tension between the electrodeposited layer and the mother plate, thereby causing peeling of the electrodeposited layer.

The electrolyte is supplied to the surface of the mother plate through the nozzle from the electrolytic cell containing the electrolyte, such electrolyte may be supplied in the same direction and in the opposite direction with respect to the traveling direction of the mother plate. In this way, the electrodeposition rate of the iron component and the nickel component on the surface of the mother plate can be further increased.

According to one embodiment of the present invention, it is to provide a method for manufacturing a solar cell substrate for CIGS with Fe as a main component. The Fe has the advantage of being light and flexible, inexpensive, and capable of mass production. That is, since it is flexible at the same time as securing a certain level of strength or hardness, cracking or breaking due to physical impact does not occur well, and is advantageous in terms of securing durability. In addition, since the manufacturing cost is low and mass production is possible, there is an advantage in terms of productivity. Furthermore, since it is easily changed into a roll-like form, it is easy to store and to control the size of the substrate to meet the needs of the customer.

The CIGS solar cell is exposed to a high temperature atmosphere of 500 to 600 ℃ during the growth of the CIGS substrate, the coefficient of thermal expansion is in the range of 8 × 10 ^-6 to 12 × 10 ^-6 . However, when Fe is exposed to such a high temperature, the thermal expansion coefficient is lower than this, which causes a problem of separation from the CIGS substrate. Therefore, in order to modify the coefficient of thermal expansion similar to the CIGS substrate, the nickel component is included to form an alloy foil made of an alloy of iron and nickel.

In the Fe-Ni alloy electrodeposition layer (thin film), in order to have the above coefficient of thermal expansion, the Ni content is 28-32% by weight or 45-75% by weight of Fe and Ni in the electrodeposition layer, that is, the alloy foil. It is preferably in% and may include residual iron and other unavoidable impurities. In this way, in order to obtain a Fe—Ni alloy electrodeposition layer (thin film) having a Ni content of 30-50% by weight, the electrolyte solution preferably contains 2-25 g / L of iron precursor and 40-60 g / L of nickel precursor. .

The electrolyte is a source of iron and nickel, which are the main components of the Fe-Ni alloy foil to be obtained in the present invention, and the iron precursor is not limited thereto, for example, with iron sulfate, iron chloride, iron nitrate and iron sulfamate. At least one selected from the group consisting of, while the nickel precursor may be at least one selected from the group consisting of, for example, but not limited to nickel sulfate, nickel chloride, nickel nitrate and nickel sulfamate.

The electrolyte solution may contain 0.1 to 8.0 g / L surfactant. By adding the surfactant, a metal ion component in the electrolyte can be uniformly dispersed to obtain an electrodeposition layer having a uniform composition as a whole. As the surfactant, any of those generally used in the art may be used, and examples thereof include, but are not particularly limited to, polyethylene glycol, sodium laureth sulfate, and the like.

Although not limited to this, the temperature of the said electrolyte solution is generally about 50 degreeC-80 degreeC. To this end, a heating means such as an electrolyte heater may be installed in the electrolyte reservoir to heat and maintain the electrolyte in the predetermined temperature range as described above.

In addition, the electrolyte solution may be appropriately added, as necessary, a conduction aid such as sodium sulfate, for example, a complexing agent such as glycolic acid, for example, a stress relaxer such as saccharin, and the content thereof is conventional. As what can be included in phosphorus quantity, it does not specifically limit here.

On the other hand, the electrolyte used for electrodeposition can be recovered by electrolyte storage tank again as needed. At this time, the recovered electrolyte solution will be lower than the concentration required for electrodeposition of the iron and nickel ion concentration in the electrolyte reservoir because the iron ions are used for electrodeposition, appropriately supplement the iron ions and nickel ions to the predetermined iron ions and nickel It can be adjusted by ion concentration.

In one embodiment of the present invention, the electrodeposition layer of the Fe-Ni alloy may be grown by using the above electrolyte, and the electrodeposition surface of the electrodeposition layer may have a uniform and fine surface roughness.

The electrodeposition process as described above may be performed a plurality of times in succession. For a plurality of electrodeposition processes, a plurality of horizontal cells may be installed. In this way, the electrodeposition process can be performed in each horizontal cell by performing the electrodeposition process through the horizontal cell a plurality of times, thereby increasing the thickness of the Fe-Ni alloy electrodeposition layer obtained. Therefore, the thickness of the Fe-Ni alloy electrodeposition layer can be controlled as needed, and even if the mother plate is supplied at a higher speed, a Fe-Ni alloy electrodeposition layer having a desired thickness can be obtained, thereby improving productivity. When a plurality of electrodeposition processes are performed, the process conditions and the composition of the electrolyte solution may be the same or different in the plurality of electrodeposition processes. The number of repetitions of the electrodeposition process is not limited, and may be appropriately selected depending on the desired degree of electrodeposition.

The thickness of the electrodeposition layer of the said Fe-Ni alloy is not specifically limited. However, when the thickness of the alloy foil is less than 20 μm, the resulting alloy foil is too thin, so that subsequent handling is not easy, and when it exceeds 70 μm, the economy may be inferior to that of manufacturing the metal foil by rolling. Therefore, it is preferable to grow an alloy electrodeposition layer in the thickness of 20-70 micrometers from the viewpoint of the ease of handling and economics of alloy foil.

On the other hand, since the electrolyte may remain on the surface of the Fe-Ni alloy electrodeposition layer formed on the mother plate, it is preferable to optionally wash the surface of the Fe-Ni alloy electrodeposition layer as necessary. Such washing may be performed using an acid solution and water, and furthermore, a flexible brush or the like may be used to effectively remove the residual electrolyte. The acidic solution may be any known to be used for metal surface cleaning, and is not particularly limited. Such washing may be performed in a state in which an electrodeposition layer is formed by electrodepositing iron and nickel on the mother plate, but the Fe—Ni alloy foil may be washed after separating the Fe—Ni alloy electrodeposition layer from the mother plate. Thereafter, if desired, high pressure air or hot gas may be sprayed on the surface of the Fe—Ni alloy electrodeposition layer or the Fe—Ni alloy foil or dried by a method such as heating.

The electrodeposited Fe—Ni alloy electrodeposition layer is separated from the mother plate to obtain a Fe—Ni alloy foil. The difference in the shear stress between the base plate and the Fe-Ni alloy electrodeposition layer can be used to separate the Fe-Ni alloy electrodeposition layer from the base plate. Since the Fe-Ni alloy electrodeposition layer is bonded by the surface tension with respect to the oxide film on a base plate, it can isolate easily by the shear stress difference. Separation of the Fe—Ni alloy electrodeposition layer due to such a shear stress difference can be carried out by passing through a plurality of rollers. Furthermore, the shear force may be separated by a difference in the moving speed of the Fe—Ni alloy electrodeposition layer and the moving speed of the mother plate. On the other hand, when electrodeposition is performed on both sides of the mother plate, the upper and lower Fe-Ni alloy electrodeposition layers may be separated at the same time, or may be separated by giving a time difference.

The obtained Fe—Ni alloy foil may be exposed to various working process temperatures depending on the intended use. For example, when the alloy foil undergoes a high temperature treatment process of 300 to 600 ° C., abnormal grain growth occurs to cause the nanostructure microstructure of the Fe—Ni alloy foil to change into a microstructured structure. Such a change in the microstructure due to the growth of abnormal grains may cause a defect in the product during the process of manufacturing the target product by applying the Fe-Ni alloy foil. For example, when an electronic circuit etc. are formed in Fe-Ni alloy foil, it may cause peeling or disconnection of the circuit during a high temperature process. Therefore, in the case where the Fe-Ni alloy foil obtained in the temperature range causing abnormal grain growth is used, the Fe-Ni alloy foil may be optionally heat-treated in advance and optionally changed into a microstructure of the microstructure in advance so that the microstructure may be formed during the process. It is desirable to prevent the change in advance. Such heat treatment may be performed after the electrodeposition layer is separated from the mother plate, as well as before the separation.

The heat treatment conditions described above may vary depending on the target microstructure, but are not particularly limited, but it is preferable that the heat treatment is optionally performed at a temperature of 300 to 600 ° C. In this case, in order to prevent oxidation of the surface during the heat treatment, it is preferable to use an inert gas atmosphere such as nitrogen and argon, and the heat treatment method may be induction heating, direct heating, or contact heating.

In one embodiment of the present invention, the electrodeposited surface of the obtained Fe-Ni alloy foil can be formed with a diffusion barrier. In the substrate for CI (G) S solar cells, a back metal layer serving as an electrode is formed on the substrate, and Fe or impurities contained in the Fe—Ni alloy may be diffused into the back metal layer. Such diffusion may reduce the efficiency of CI (G) S solar cells or render the use of the cells impossible. Therefore, it is preferable to form a diffusion barrier film between the Fe-Ni alloy substrate and the back metal layer.

The diffusion barrier is not particularly limited but preferably has a thickness of 100-500 nm. If it is less than 100 nm, the effect of preventing diffusion may not be sufficient, and if it exceeds 500 nm, there is a problem in that economic efficiency is lowered.

The diffusion barrier component may be Cr, Ni, or a mixture thereof. The Cr or Ni forms a dense structure by electroplating, whereby the diffusion of Fe present in the substrate can be effectively prevented. In addition, the diffusion barrier may contribute to securing resistance, and also provides an effect of prolonging the life of the solar cell. Such a diffusion barrier can be carried out by electroplating a material containing Cr, Ni or a combination thereof on the surface of the Fe-Ni alloy electrodeposition layer or Fe-Ni alloy foil. Formation of the diffusion barrier film by the electroplating can be performed by a conventional electroplating method, it will be able to be carried out by those skilled in the art to which the present invention pertains even if not specifically described in the present invention.

By doing in this way, the alloy foil which has the flat surface in which the surface roughness of the surface in which the diffusion prevention film was formed is minute and uniformly formed can be obtained. By having a flat surface in this way, when using it as a CIGS solar cell substrate, it is possible to prevent problems such as shorts that may occur when having a non-uniform rough surface roughness. Furthermore, the alloy foil thus obtained is an alloy of Fe and Ni components, and the thermal expansion coefficient is adjusted to have a value similar to that of other substrate layers of CIGS solar cells, even if exposed to a high temperature atmosphere of 500-600 ° C. during CIGS solar cell substrate formation. It is possible to prevent cracking and breaking of the solar cell, and it is light including Ni and has excellent strength, hardness, durability and / or corrosion resistance.

The Fe-Ni alloy foil may further form a planarization film on the diffusion barrier. The CIGS solar cell substrate requires the same level of surface roughness as glass. The Fe-Ni alloy foil obtained above has a uniform and fine surface roughness with a surface roughness of 100 nm or less on the electrodeposition surface side, and satisfies the surface roughness required as a CIGS solar cell substrate. It can be made to have a uniform surface roughness. At this time, the planarization film formed may be formed of a resin film, whereby the surface roughness can be controlled to 4 nm or less, for example, 2 nm or less. At this time, the smaller the surface roughness is preferable, the lower limit is not particularly limited, for example, may be 0.1nm or more.

Although the said resin film does not specifically limit the kind, For example, polymeric resins, such as a polyethylene terephthalate, a polyethylene naphthalate, a polycarbonate, polyester, a polyimide, are mentioned. Among them, polyimide-based resins may be preferably used. Since the polyimide-based resins have excellent thermal stability, chemical resistance, and durability, they may be preferably applied to solar cell substrates.

The planarization film is not particularly limited in terms of its thickness, but is preferably used in a controlled range of 0.1 to 20 µm in consideration of the thickness of the metal plate serving as the mother substrate.

The Fe-Ni alloy foil obtained in this way can be wound up, and can be cut suitably according to the winding amount. Furthermore, the base plate from which the metal layer is separated can also be wound up and reused as the base plate. However, the separated mother plate may have an electrolyte solution or other impurities in the electrodeposition process, it is preferable to keep the surface of the mother plate clean by drying after washing. Furthermore, when the mother plate is bonded for continuous supply of the mother plate, the mother plate may be cut to an appropriate length according to the amount of winding of the mother plate, and in this case, it is preferable to cut based on the bonding portion.

Hereinafter, a horizontal electroforming apparatus for manufacturing a Fe-Ni alloy substrate for a solar cell by a horizontal electroforming method according to one embodiment of the present invention will be described with reference to FIG. 1. 1 is not limited to the horizontal electroforming apparatus used for manufacturing a Fe-Ni alloy substrate for solar cells by the horizontal electroforming method according to one embodiment of the present invention as an example of a horizontal electroforming apparatus.

The horizontal pole device 100 includes a mother plate supply device 10, a horizontal cell 30, an electrolyte supply device and a Fe-Ni alloy foil separator 51.

The mother plate feeding device 10 may include a winding machine to supply the mother plate 11. In order to continuously supply the base plate 11, a plurality of the winding machines may be installed, and when the base plate 11 is exhausted in one winding machine, a new base plate 11 may be supplied from another winding machine. This base plate 11 may comprise joining means 12, such as welding, for joining the ends of the previously provided base plate 11 and the tip of the next base plate 11 to be provided for continuous feeding.

Furthermore, since the electrodeposition layer electrodeposited on the base plate 11 transfers the surface roughness of the base plate 11, it is represented in substantially the same way to the Fe-Ni alloy foil from which the surface roughness of the base plate 11 is obtained. Therefore, the grinding | polishing means 13 for giving an appropriate surface roughness to the base plate 11 can be further included as needed. Such polishing means 13 is not particularly limited, and may include mechanical polishing such as polishing, chemical polishing such as etching, and mechanical chemical polishing such as a CMP method mainly used in semiconductor processes. The chemical polishing, mechanical polishing and chemical mechanical polishing means may be used alone or in combination thereof.

Impurities may be present on the surface of the mother plate 11, so that additional washing may be necessary as necessary to remove them, and thus, the pre-cleaning device 14 may be additionally included as necessary. The cleaning of the surface of the base plate 11 may use an acid solution such as diluted hydrochloric acid or sulfuric acid and water. Furthermore, a drying apparatus (not shown) for drying the mother plate 11 may be further included as necessary. Drying may be carried out by adding air to a high pressure or by applying a hot gas, or by heating the mother plate.

Horizontal pole apparatus 100 according to an embodiment of the present invention includes a horizontal cell 30 that is separated from the mother plate feeding device (10). In the case of a conventional electroforming apparatus using a drum, there is a problem that foreign matters generated during polishing are contaminated into the electrolyte solution to contaminate the electrolyte solution in order to give surface roughness to the drum surface, but as described above, the horizontal cell 30 has the mother plate feeding device 10. ), It is possible to prevent such a problem.

The horizontal cells 30 are spaced apart from the substrate rolls 31 and 31 ′, which serve to transfer the mother plate 11 and the cathode power, and the mother plate 11 at regular intervals, A current supply for supplying a current having a (-) charge and a (+) charge to the anode electrode 32, the conductor rolls 31 and 31 ', and the anode electrode 32 disposed on one or both sides of 11), respectively. Apparatus 33 and electrolyte supply device for receiving an electrolyte for the electrolytic reaction.

The conductor rolls 31, 31 ′ serve as a conveying means for transferring the mother plate into the horizontal cell 30 and discharging it from the horizontal cell 30, while the substrate rolls 31 and 31 ′ By connecting the cathode power source, an electrolytic precipitation reaction is performed such that iron and nickel ions are deposited on the mother plate by an electrolytic reaction between the anode electrode 32 and the mother plate 11. These contact rolls 31 and 31 'come into contact with both edges in the width direction of the base plate 11 to transfer the base plate 11 into the horizontal cell 30 and discharge it from the horizontal cell 30.

In one embodiment of the present invention, since the base plate 11 uses a flexible conductive base plate, a drooping phenomenon may occur when passing through the horizontal cell 30, in which case the base plate 11 and the anode electrode Since the distance from (32) may change to cause a difference in current density, a Fe-Ni alloy foil having a uniform thickness may not be obtained. Accordingly, in order to prevent the base plate 11 from sagging, the rotational speeds of the inlet conductor roll 31 and the outlet conductor roll 31 'are varied, that is, the outlet conductor roll 31' is rotated. It is preferable to make the speed faster than the rotational speed of the inlet-side conductor roll 31 to prevent sagging due to the weight of the mother plate.

Meanwhile, the conductor rolls 31 and 31 ′ transmit the current supplied from the current supply device 33 to the base plate 11 so that the base plate 11 can function as a cathode electrode, thereby providing the anode electrode 32. It is possible to cause the electrolytic precipitation reaction by the action of.

The anode electrode 32 is spaced apart from the base plate 11 passing through the horizontal cell 30 by a predetermined interval. The anode electrode 32 and the mother plate 11 are spaced apart and provided as a flow path through which the electrolyte is supplied and distributed therebetween. As described above, the iron and nickel ions in the electrolyte are acted upon by the mother plate 11 serving as the cathode electrode. An electrolytic reaction may occur, in which electrolytic precipitates on the base plate. When the electrolyte is supplied at high speed, the electrodeposition speed of iron and nickel ions to the surface of the base plate 11 can be increased. In the case of electroforming using a conventional drum cell, the flow path forms a curvature so that the flow rate of the electrolyte is gradually decreased. There was a problem causing a decrease in electrodeposition speed. However, since the flow path of the electrolyte is formed in the plane as described above, it is possible to minimize the decrease in the speed of the flow field with respect to the supply of the electrolyte, and thus increase the electrodeposition rate.

The anode electrode 32 may be installed on both top and bottom surfaces of the base plate 11 to cause an electrolytic precipitation reaction of metal on both sides of the base plate 11. By doing in this way, the yield of Fe-Ni alloy foil can be raised.

The electrolyte solution contains an iron precursor and a nickel precursor in water, and additionally surfactants, conduction aids (for example, sodium sulfate), complexing agents (for example, glycolic acid), and stress relieving agents (for example, saccharin) as necessary. ) May be included.

On the other hand, the current supply device 33 is to supply a (-) current and a (+) current to the conductive rolls (31, 31 ') and the anode electrode 32, respectively, if it is generally applicable without particular limitation As applicable to the present invention, a detailed description thereof will be omitted.

The electrolyte supply device includes an electrolyte storage tank 34 for storing and accommodating an electrolyte solution and an electrolyte supply nozzle 38 for supplying an electrolyte solution to the surface of the base plate 11, and supplying an electrolyte solution from the electrolyte storage tank 34 through an electrolyte supply pipe. It is moved to the nozzle 38. The electrolyte supply nozzle 38 may be installed to be supplied only to one surface of the mother plate 11, or may be installed on both sides of the electrolyte supply to both surfaces of the mother plate 11.

Meanwhile, the electrolyte storage tank 34 includes an electrolyte heater 35 for heating the electrolyte, an electrolyte filter 36 for removing impurities such as sludge included in the electrolyte, and an electrolyte pump 37 for supplying the electrolyte to the horizontal cell. Etc. may be further included as needed.

Furthermore, the current density of the electrolyte supplied to the base plate 11 may be relatively low at both edges in the width direction as compared with the central portion of the base plate 11. In this case, the electrolyte is deposited on the base plate 11. The electrodeposition amount of the Fe-Ni alloy is reduced, so that the thickness of the Fe-Ni alloy Fe-Ni alloy foil becomes relatively thin, so that the Fe-Ni alloy foil having a uniform thickness as a whole may not be obtained. In this case, in the case where the obtained Fe—Ni alloy layer is separated from the base plate 11, the Fe—Ni alloy Fe—Ni alloy foil may be torn at the edges and a defect may occur, and the Fe—Ni alloy separated from the base plate 11 may be damaged. In order to make Ni alloy foil have a uniform thickness, the post-processing process which cuts a thin thickness edge is needed.

Therefore, it is necessary to prevent the precipitation of the Fe-Ni alloy in advance in the edge portion to suppress the thickness variation, for this purpose, it is possible to install an edge mask (not shown) so that the electrolyte is not supplied to the edge of the mother plate. By providing such an edge mask, not only the formation of a thin Fe-Ni alloy foil at the edge of the base plate 11 is suppressed, but also the electrode rolls are prevented from being formed at the edges of the base plate 11 so that the conductor rolls 31 and 31 'are applied to the base plate 11. This can supply current continuously.

The electrolyte supply nozzle 38 supplies the electrolyte at a high speed through the horizontal passage formed by the mother plate 11 and the anode electrode 32. In this case, the electrolyte may be installed such that the electrolyte is supplied in the same direction and in the opposite direction to the traveling direction of the base plate 11 with respect to the electrolyte supply nozzle 38. By doing in this way, the effect of electrodeposition substantially can be acquired. That is, the electrolyte supplied in the opposite direction can obtain the effect of primary electrodeposition, in which a relatively small amount of short time for the electrolyte to contact the mother plate 11 is electrodeposited due to the difference in relative speed with the mother plate 11, and in the same direction. By supplying to the electrode, it is possible to obtain the effect of the secondary electrodeposition, in which the electrolyte solution contacts the base plate 11 for a longer time and is relatively electrodeposited in comparison with the primary electrodeposition.

The horizontal cells 30 as described above may be provided in plural in series in the traveling direction of the mother plate 11. Even if a plurality of horizontal cells 30 are installed, the electrodeposited layer is peeled from the mother plate 11 during movement by being disposed in series in the mother plate 11 traveling direction. By installing a plurality of horizontal cells, an electrodeposition layer having a desired thickness can be formed on the base plate 11 even though the base plate advances at a higher speed while reducing the electrodeposition amount through one cell, thereby improving the productivity of the Fe-Ni alloy foil. Can be improved. Electrodeposition conditions and electrolyte solutions in the plurality of horizontal cells 30 may be the same or different.

As described above, the base plate 11 having the electrodeposition layer formed thereon is discharged through the outlet-side conductor roll 31 ', and after discharge, the Fe-Ni alloy foil separating device 51 is used to remove the Fe- from the base plate 11. The Ni alloy layer is separated to obtain the Fe—Ni alloy foil 50. Since the Fe-Ni alloy foil 50 is bonded by surface tension on the base plate 11 on which an oxide film is formed on the surface, the Fe-Ni alloy foil 50 may be separated by a difference in shear force between the Fe-Ni alloy foil 50 and the base plate 11. Can be. Therefore, the Fe-Ni alloy foil separator 51 is preferably capable of imparting a shear stress for separating the Fe-Ni alloy foil 50 from the base plate 11, for example, a plurality of rollers Can be installed. It is also preferable to separate by the generated shear force. In addition, it is preferable to generate the moving speed difference between the Fe-Ni alloy foil 50 and the mother plate 11 to separate the upper and lower Fe-Ni alloy foil 50 at the same time or give a time difference.

After separating the Fe-Ni alloy foil 50 from the mother board 11, Fe-Ni alloy foil winding device 55 and the mother board winding device for winding the Fe-Ni alloy foil 50 and the mother board 11 ( 72). For example, it can be wound up to a cylindrical winder. It can be wound up in a suitable amount according to the winding amount to the said winding machine, it can cut and wind up another winding machine. Fe-Ni alloy foil cutting device 54 and the mother plate cutting device 71 as necessary for the cutting, it is more preferable to cut at the bonding portion of the base plate (11).

In addition, the horizontal pole device 100 according to an embodiment of the present invention is discharged from the horizontal cell 30 as necessary before or after separating the Fe-Ni alloy foil 50 or after the Fe- as necessary The post-treatment apparatus of Ni alloy foil can be further installed as needed. Examples of such a post-treatment apparatus include a post-cleaning apparatus 52, a drying apparatus (not shown), a heat treatment apparatus 53, and the like.

The cleaning device 52 is a device for removing by using an acid solution such as hydrochloric acid or sulfuric acid diluted with an electrolyte solution and foreign matter that may be present on the surface of the Fe-Ni alloy foil 50, and water, such as a high pressure spray The device can be used. Furthermore, after such washing, it may be an injection means for injecting air at a high pressure or hot gas to remove moisture existing on the surface of the Fe-Ni alloy foil 50, or heating means for drying by heating. Can be.

Furthermore, the Fe—Ni alloy foil 50 formed by electrodeposition has a nanostructure of microstructure, and may further include the heat treatment means 53 as necessary to secure a target microstructure. The heat treatment of the Fe-Ni alloy foil 50 uses a temperature of 350 ~ 600 ℃, it is preferable to use a nitrogen, argon gas atmosphere to prevent oxidation of the surface during heat treatment, induction heating, direct heating as a heat treatment method , Contact heating can be used.

In addition, in one embodiment of the present invention, it may include a conventional electroplating equipment (not shown) for forming a diffusion barrier film of Cr or Ni on the surface of the electrodeposited layer or metal foil obtained. Electroplating for the formation of such a diffusion barrier film can be carried out using a conventional electroplating equipment, a detailed description thereof will be omitted, and may have a structure such as a horizontal cell. After the electrodeposition layer is formed, an electroplating facility for electroplating may be provided, and the diffusion barrier film may be formed by passing the obtained metal foil through a separate electroplating facility.

As described above, the method for manufacturing the Fe-Ni alloy foil and the horizontal pole device by the pole method according to each embodiment of the present invention has been described, but such a method and device is not limited to these embodiments, and It will be understood by those skilled in the art that the present invention may be appropriately modified.

Hereinafter, an Example is given and this invention is demonstrated more concretely. However, the following examples are examples of the present invention, and the present invention is not limited thereto.

Example

Example 1

STS 304 steel sheet was used as the mother board. After the steel sheet was polished to a surface roughness (Rz) of 500 nm or less through super mirror processing, plating pretreatment was performed on the mother plate through pickling / electrolytic polishing.

An electrolytic solution formed by supplying the base plate on which the plating pretreatment is completed is supplied at a feed rate of 50 mpm (meter per minute) to the upper surface of the anode electrode of the horizontal cell of the horizontal electroforming apparatus having the configuration as shown in FIG. 1. The electrolyte was supplied to the flow path in Reynolds number (Re) 1000.

The electrolyte solution was pH 3 composed of FeCl ₂ · 4H ₂ O 10g / l, NiCl ₄ · 6H ₂ O 55g / l, H ₃ BO ₃ 25g / l and polyethylene glycol 3.0g / l, 35 ℃ was used a solution . At this time, an electrolytic reaction was performed at a current density of 5 A / dm 2 to form a 40 μm Fe—Ni electrodeposition layer.

The obtained electrodeposition layer was separated to obtain a Fe—Ni thin film. The thin film thus obtained was sufficiently washed with water and then dried.

The prepared separator was a Fe-Ni alloy thin film having a Fe content of 46wt%, a thermal expansion coefficient of 6.4 × 10 ^-6 m / K, the surface roughness of the opposite side of the electrodeposited surface was 0.06㎛.

The obtained thin film was electroplated using a 45 ° C. plating solution containing 250 g / l of CrO ₃ and 2.5 g / l of H ₂ SO ₄ at 20 A / dm 2 and 2 to 3 pH to form a Cr 300 nm diffusion barrier film.

A CIGS solar cell SiOx / Na thin film / Mo electrode / CIGS / Cds / AZO / Al / Ni device was fabricated on the diffusion barrier of the formed substrate.

The characteristics of the electroforming elements obtained in the present embodiment were compared with those using glass substrates. The results are shown in Table 1.

Glass substrate Example 1 Jsc (mA / ㎠) 36.46 36.63 Voc (V) 0.63 0.61 FF. (%) 70.03 70.4 Eff. (%) 16.14 15.95

As can be seen from Table 1, when manufacturing the CIGS device using the thin film obtained by the present embodiment, it can be seen that similar performance can be secured compared to the existing glass substrate.

On the other hand, when using a rolling agent obtained by manufacturing a thin film of stainless steel by the conventional rolling method, the Rz value of stainless steel is 402 µm. It was difficult.

10: Bedplate Feeder 11: Bedplate
12: bonding means 13: polishing means
14: pre-washing device 30: horizontal cell
31, 31 ': Conductor roll 32: anode electrode
33: current supply device 34: electrolyte reservoir
35: electrolyte heater 36: electrolyte filter
37: electrolyte pump 38: electrolyte nozzle
50: Fe-Ni alloy foil 51: peeling roll
52: post-cleaning apparatus 53: heat treatment apparatus
54: Fe-Ni alloy foil cutting device 55: Fe-Ni alloy foil winding device
71: bed cutting device 72: bed sheet winding device
100: horizontal pole

Claims (10)

An electrolyte is supplied between a conductive base plate horizontally supplied in a predetermined direction and an anode electrode spaced apart from one side or both sides of the conductive base plate, wherein the electrolyte is 2 to 25 g / L of iron precursor and 40 to 60 g / of nickel precursor. An electrolyte supply step comprising L;
Applying a current to the conductive base plate and an anode electrode disposed on one or both surfaces of the conductive base plate to apply the current to electrodeposit the iron and nickel contained in the electrolyte on one or both sides of the conductive base plate;
A peeling step of separating an alloy electrodeposition layer of iron and nickel formed by electrodeposition of iron and nickel from the conductive mother plate to obtain an alloy foil of iron and nickel; And
A diffusion barrier film forming step of forming a diffusion barrier of at least one metal selected from the group consisting of chromium and nickel on the electrodeposited surface of the alloy foil of iron and nickel
Method for producing a Fe-Ni alloy substrate for CI (G) S solar cells comprising a.
The method of claim 1, wherein the diffusion barrier layer has a thickness of 100-500 nm Fe-Ni alloy substrate manufacturing method for CI (G) S solar cells.
The method of claim 1, wherein the iron precursor is at least one selected from the group consisting of iron sulfate, iron chloride, iron nitrate, and iron sulfamate, and the nickel precursor is a group consisting of nickel sulfate, nickel chloride, nickel nitrate, and nickel sulfamate At least one selected from the method of manufacturing a Fe-Ni alloy substrate for a solar cell.
The method of claim 1, wherein the electrolyte solution further comprises 0.1-8.0 g / L of surfactant which is polyethylene glycol, sodium laureth sulfate or a mixture thereof.
The Fe-Ni alloy substrate according to claim 1, wherein the Fe-Ni alloy substrate for solar cells has a surface roughness (Rz) of 0.1 to 100 nm on the surface where the diffusion barrier is formed. Way.
The method of claim 1, wherein the Fe—Ni alloy substrate has a thickness of 20-70 μm.
The method of claim 1, wherein the Fe-Ni alloy substrate is a Fe-Ni alloy substrate for a CI (G) S solar cell, characterized in that consisting of 28 to 32% by weight of nickel and the balance iron and other unavoidable impurities.
The method of claim 1, wherein the Fe-Ni alloy substrate is made of 45 to 75% by weight of nickel and the balance of iron and other unavoidable impurities.
The method of claim 1, further comprising a planarization film forming step of forming a planarization film of a polymer resin selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyester and polyimide on the diffusion barrier. Method for manufacturing Fe-Ni alloy substrate for CI (G) S solar cell.
10. The method of manufacturing a Fe-Ni alloy substrate for a CI (G) S solar cell according to any one of claims 1 to 9, wherein the electrolyte supply step and the current application step are performed a plurality of times.

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