KR101022822B1 - Method for manufacturing photovoltaic device - Google Patents

Abstract

The method of manufacturing a photovoltaic device of the present invention comprises the steps of placing a substrate on a loading plate in a reaction chamber, contacting the substrate placed on the loading plate and a substrate holder, injecting a source gas and a doping gas, and then decomposing it into a plasma. Depositing a thin film semiconductor layer, injecting an inert gas to form a plasma of the inert gas, and separating the substrate and the substrate holder.

Photovoltaic, Plasma, Static Electricity

Description

Manufacturing method of photovoltaic device {METHOD FOR MANUFACTURING PHOTOVOLTAIC DEVICE}

The present invention relates to a method of manufacturing a photovoltaic device.

Recently, as the prediction of depletion of existing energy sources such as oil and coal is increasing, interest in alternative energy to replace them is increasing. Among them, photovoltaic devices are particularly attracting attention because they are rich in energy resources and have no problems with environmental pollution.

Photovoltaic devices utilize photovoltaic phenomena that convert light into electrical energy. Photovoltaic devices come in various forms, such as using silicon semiconductors or compound semiconductors. For example, in the case of a silicon semiconductor, when light is incident on a silicon semiconductor doped with an impurity, energy of the light generates electrons and holes in the semiconductor, and current flows to the outside through electrodes and conductors connected to the semiconductor.

As interest in such a photovoltaic device is increased and a market is formed, various studies are being conducted to reduce the manufacturing cost and increase the yield of the photovoltaic module.

It is to provide a method of manufacturing a photovoltaic device that can reduce the manufacturing cost by improving the yield of the photovoltaic device of the present invention.

Technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

The method of manufacturing a photovoltaic device of the present invention comprises the steps of placing a substrate on a loading plate in a reaction chamber, contacting the substrate placed on the loading plate and a substrate holder, injecting a source gas and a doping gas, and then decomposing it into a plasma. Depositing a thin film semiconductor layer, injecting an inert gas to form a plasma of the inert gas, and separating the substrate and the substrate holder.

The manufacturing method of the photovoltaic device of the present invention eliminates static electricity during formation of a microcrystalline silicon layer or an amorphous silicon layer to prevent breakage of the substrate in the process of separating the substrate from the substrate holder, thereby improving the manufacturing cost by improving the yield of the photovoltaic device. Can be reduced.

Next, a method of manufacturing a photovoltaic device according to an embodiment of the present invention will be described in detail with reference to the drawings.

1A to 1H illustrate a manufacturing process of a photovoltaic module according to an embodiment of the present invention.

As shown in FIG. 1A, a substrate 100 is prepared first. The substrate 100 may be an insulating transparent substrate 100.

As shown in FIG. 1B, the first electrode 210 is formed on the glass substrate 100. In an embodiment of the present invention, the first electrode 210 may be formed by a chemical vapor deposition (CVD) method, and a transparent conductive oxide (TCO) such as tin oxide (SnO ₂ ) or zinc oxide (ZnO). It may be made of.

As shown in FIG. 1C, the laser is irradiated to the first electrode 210 side or the glass substrate 100 side to scribe the first electrode 210. As a result, a first separation groove 220 is formed in the first electrode 210. That is, since the first separation groove 220 penetrates the first electrode 210, a short circuit between adjacent first electrodes 210 is prevented.

As illustrated in FIG. 1D, the photoelectric conversion layer 230 is stacked by CVD to cover the first electrode 210 and the first separation groove 220. In this case, the photoelectric conversion layer 230 may be stacked in order of the p-type semiconductor layer, the intrinsic semiconductor layer, and the n-type semiconductor layer. In order to form a p-type semiconductor layer, when a source gas containing silicon such as mono silane (SiH4) and a doping gas containing a group III element such as B2H6 are mixed in the reaction chamber, the p-type semiconductor layer is stacked by CVD. . Then, when only the source gas containing silicon flows into the reaction chamber, an intrinsic semiconductor layer is formed on the p-type semiconductor layer by CVD. Finally, when a doping gas containing a Group 5 element such as PH 3 and a raw material gas containing silicon are mixed, an n-type semiconductor layer is laminated on the intrinsic semiconductor layer by the CVD method. Accordingly, the photoelectric conversion layer 230 disposed on the first electrode 210 includes an amorphous semiconductor layer stacked in the order of a p-type semiconductor layer, an intrinsic semiconductor layer, and an n-type semiconductor layer.

The manufacturing process of the photoelectric conversion layer 230 will be described later in detail with reference to FIGS. 2A to 2.

As shown in FIG. 1E, the laser is irradiated to the glass substrate 100 side or the photoelectric conversion layer 230 side in the air to scribe the photoelectric conversion layer 230. As a result, the second separation groove 240 is formed in the photoelectric conversion layer 230.

As illustrated in FIG. 1F, a zinc oxide back reflection layer 250 is formed to cover the photoelectric conversion layer 230 and the second separation groove 240 by CVD or sputtering. The second electrode 260 may be a metal electrode such as Al or Ag. At this time, if the zinc oxide back reflection layer 250 is formed to be thicker than 1.5 μm, the zinc oxide back reflection layer 250 may serve as a second electrode, and thus the metal electrode may be lost.

As shown in FIG. 1G, the laser is irradiated in the air to scribe the photoelectric conversion layer 230, the zinc oxide back reflection layer 250, and the second electrode 260. Accordingly, a third separation groove 270 is formed in the photoelectric conversion layer 230, the zinc oxide back reflection layer 250, and the second electrode 260.

As shown in FIG. 1H, a silver paste is applied to the first electrode 210 and the zinc oxide back reflection layer 250, and a bus bar (BB) is attached to a conductive paste such as silver paste. . The conductive paste and the bus bar BB are connected to a junction box (not shown) to supply electricity generated from the photoelectric change layer 230 to the outside by light irradiation. In order to protect the photovoltaic cell 200 including the photoelectric conversion layer 230, the first electrode 210, and the zinc oxide back reflection layer 250, the first protective layer 300 is formed by a lamination method. To cover some or all of 200). The first passivation layer 300 may include EVA (Ethylene Vinyl Acetate). In addition, the second passivation layer 400 may be formed on the first passivation layer 300. The second protective layer 400 is a TPT in which a poly-vinyl fluoride (PVF) film, an Al foil, a poly-ethyllen terephthalate (PET) film, and a poly-vinyl fluoride (PVF) film are laminated in order to form a sandwich structure. It may be a back sheet of the structure. In addition, the second protective layer 400 may include a back sheet in which a poly-vinylidene fluoride (PVDF) film, an Al foil, a poly-ethylen terephthalate (PET) film, and a poly-vinyldiene fluoride (PVDF) film are sequentially stacked. can do.

In the method of manufacturing a photovoltaic device according to an embodiment of the present invention, a plasma of an inert gas is formed in a reaction chamber after a thin film semiconductor layer is formed to remove static electricity from the substrate and the substrate holder.

2A to 2 illustrate a manufacturing process of the photoelectric conversion layer.

As shown in FIG. 2A, the glass substrate 100 lies on a loading plate 310 in the reaction chamber, and is formed by a coil 221 wound on a substrate holder 320. The substrate 100 is heated to 150 ° C to 300 ° C.

Into the reaction chamber, a source gas containing silicon such as mono silane (SiH4), a carbon source gas such as CH4, a reaction gas containing group III elements such as hydrogen and B2H6 are mixed and a high voltage with 13.56 MHz supplied from outside Supplied. As a result, discharge occurs to decompose the source gas, and a p-type semiconductor layer 230p such as a p-type silicon carbide window layer is stacked on the first electrode 310.

As shown in FIG. 2B, when the p-type semiconductor layer 230p is stacked to a predetermined thickness, the reaction gas containing the source gas, the carbon source gas hydrogen, and the Group 3 element is removed, and an inert gas such as H ₂ , Ar, or N ₂ is removed. Is injected. At this time, when a high voltage is supplied, the inert gas becomes a plasma state. The inert gas in the plasma state eliminates static electricity between the glass substrate 100 on which the p-type semiconductor 230p is stacked and the substrate holder 320.

That is, since the glass substrate 100 and the substrate holder 320 contact each other during the formation of the p-type silicon carbide window layer, static electricity is generated by friction between the glass substrate 100 and the substrate holder 320. Static electricity of the glass substrate 100 and the substrate holder 320 prevents the substrate holder 320 from being separated from the glass substrate 100. Therefore, when the substrate holder 320 moves downward, the glass substrate 100 is also exerted a force in the moving direction of the substrate holder 320 by static electricity. At this time, since the glass substrate 100 is placed on the loading plate 310, the glass substrate 100 may be damaged.

Therefore, after the p-type semiconductor 230p is formed on the first electrode 210, the plasma of the inert gas removes static electricity between the glass substrate 100 and the substrate holder 320, thereby removing the glass substrate 100 and the substrate holder 320. The glass substrate 100 is prevented from being broken upon separation of the substrate.

As such, after the static electricity is removed by the plasma, the glass substrate 100 and the substrate holder 320 are separated.

In the embodiment of the present invention, the inert gas may include Ar, N2, H2, in the case of H2 has a low molecular weight and the diffusion rate is also low cost. The flow rate of H2 introduced into the reaction chamber to remove static electricity may be 100 sccm or more and 10000 sccm or less. Where sccm is an abbreviation of standard cubic cm per minute. When the flow rate of H2 is 100 sccm or more and 10000 sccm or less, static electricity can be removed without a sharp increase in manufacturing cost due to hydrogen gas. That is, if the flow rate of H2 is less than 100 sccm, the static elimination is not made sufficiently, and if more than 10000 sccm, the manufacturing cost increases.

The excitation power of H2 supplied from the outside may be 100 W or more and 12000 W or less. When the excitation power of H2 is 100 W or less, the H2 gas changes insufficiently in the plasma state. In addition, when the excitation power is more than 10000 W, the momentum of the hydrogen cation is excessively large, which may damage the film quality of the p-type semiconductor 230p. That is, when the excitation power is supplied, the hydrogen gas is in a plasma state where electrons and hydrogen cations are separated, and the hydrogen cations move in accordance with the polarity of the supplied voltage. Therefore, if the excitation power is too large, the momentum of the hydrogen cation is also increased, so that the hydrogen cation collides with the film quality of the p-type semiconductor layer and damages the film quality. When the excitation power of H2 is 100 W or more and 12000 W or less, static electricity is stably removed without damaging the film quality.

The time for which the hydrogen gas maintains the plasma state in the reaction chamber may be 10 seconds or more and 1 minute or less. If the time to maintain the plasma state is more than 10 seconds and less than 1 minute, it is possible to remove the static electricity and to reduce the damage to the film.

As shown in FIG. 2C, the glass substrate 100 on which the p-type semiconductor 230p is formed is placed on the loading plate 310 again, and the substrate holder 320 and the glass substrate 100 contact each other. It is heated to 150 ℃ to 300 ℃. An intrinsic semiconductor layer 230i such as intrinsic silicon is formed on the p-type semiconductor 230p. To this end, a source gas containing silicon such as hydrogen and monosilane (SiH 4) is supplied to the reaction chamber, and a high voltage with 13.56 MHz is supplied. As a result, plasma discharge occurs to decompose the source gas, and the intrinsic semiconductor layer 230i is stacked on the p-type semiconductor 230p.

Another silicon may be formed immediately after the intrinsic semiconductor layer 230i is formed, but an electrostatic removal process may be performed after the intrinsic semiconductor layer 230i is formed.

As shown in FIG. 2D, after the source gas is removed, an inert gas is injected into the reaction chamber to remove static electricity between the substrate holder 320 and the glass substrate 100. The inert gas can include Ar, N2, H2. The flow rate of H2 flowing into the reaction chamber may be 100 sccm or more and 10000 sccm or less and the excitation power of H2 may be 100 W or more and 12000 W or less. In addition, the time for maintaining the plasma state of the hydrogen gas in the reaction chamber may be 10 seconds or more and 1 minute or less. Since the description of the flow rate of the hydrogen gas, the excitation power, and the time for maintaining the plasma state has been made above, it is omitted.

As shown in FIG. 2E, a buffer layer 230b may be formed on the p-type semiconductor 230p instead of the intrinsic semiconductor layer 230i. The glass substrate 100 on which the p-type semiconductor 230p is formed is placed on the loading plate 310 again, and the substrate holder 320 and the glass substrate 100 are in contact with each other and heated to 150 ° C to 300 ° C. do. Monosilane (SiH4), hydrogen, B2H6 and methane gas (CH4) are injected into the reaction chamber to form the buffer layer 230b. When a high voltage with 13.56 MHz is supplied, discharge occurs to decompose the source gas and a buffer layer 230i is formed on the p-type semiconductor 230p.

The buffer layer 230b removes a defect existing at an interface between the p-type semiconductor 230p and the intrinsic semiconductor layer 230i formed thereon, and the p-type impurity included in the p-type semiconductor 230p includes the intrinsic semiconductor layer ( 230i) to prevent photo sensitivity from being reduced.

After the buffer layer 230b is formed, another silicon may be formed on the intrinsic semiconductor layer 230i as shown in FIG. 2C, but an electrostatic removal process may be performed after the buffer layer 230b is formed.

As shown in FIG. 2F, an inert gas is injected into the reaction chamber to remove static electricity between the substrate holder 320 and the glass substrate 100 after the reaction gas is removed. The inert gas can include Ar, N2, H2. The flow rate of H2 flowing into the reaction chamber may be 100 sccm or more and 10000 sccm or less and the excitation power of H2 may be 100 W or more and 12000 W or less. In addition, the time for maintaining the plasma state of the hydrogen gas in the reaction chamber may be 10 seconds or more and 1 minute or less. Since the description of the flow rate of the hydrogen gas, the excitation power, and the time for maintaining the plasma state has been made above, it is omitted.

As shown in FIG. 2G, the glass substrate 100 on which the p-type semiconductor 230p, the buffer layer 230b, and the intrinsic semiconductor layer 230i are formed, or the p-type semiconductor 230p and the intrinsic semiconductor layer 230i are formed. This is again placed on the loading plate 310, the substrate holder 320 and the glass substrate 100 in contact with and heated to 150 ℃ to 300 ℃. An n type semiconductor layer 230n such as n type silicon is formed on the intrinsic semiconductor layer 230i. To this end, a source gas containing silicon such as hydrogen or mono silane (SiH 4) and a doping gas containing a Group 5 element such as PH 3 are mixed and an externally supplied high voltage with 13.56 MHz is supplied to the reaction chamber. As a result, plasma discharge occurs to decompose the source gas, and the n-type semiconductor layer 230n is stacked on the intrinsic semiconductor layer 230i.

After the n-type semiconductor layer 230n is formed, the process may proceed to the next process, but after the n-type semiconductor layer 230n is formed, the static electricity removing process may be performed.

As shown in FIG. 2H, an inert gas is injected into the reaction chamber to remove static electricity between the substrate holder 320 and the glass substrate 100 after the reaction gas is removed. The inert gas can include Ar, N2, H2. The flow rate of H2 flowing into the reaction chamber may be 100 sccm or more and 10000 sccm or less and the excitation power of H2 may be 100 W or more and 12000 W or less. In addition, the time for maintaining the plasma state of the hydrogen gas in the reaction chamber may be 10 seconds or more and 1 minute or less. Since the description of the flow rate of the hydrogen gas, the excitation power, and the time for maintaining the plasma state has been made above, it is omitted.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. There will be. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, It is intended that all changes and modifications derived from the equivalent concept be included within the scope of the present invention.

1A to 1H illustrate a manufacturing process of a photovoltaic device according to an embodiment of the present invention.

2A to 2H illustrate a manufacturing process of the photoelectric conversion layer.

Claims (12)

Placing the substrate on a loading plate in the reaction chamber; Contacting a substrate placed on the loading plate with a substrate holder; Injecting a source gas and a doping gas and decomposing the same into a plasma to deposit a thin film semiconductor layer; Injecting an inert gas to remove static electricity between the substrate and the substrate holder to form a plasma of the inert gas; And Separating the substrate from the substrate holder Method of manufacturing a photovoltaic device comprising a. The method of claim 1, And the thin film semiconductor layer is one of a p-type semiconductor layer, an intrinsic semiconductor layer, and an n-type semiconductor layer. The method of claim 1, And forming a buffer layer on the thin film semiconductor layer, injecting the inert gas, and forming a plasma of the inert gas. The method according to any one of claims 1 to 3, The inert gas comprises hydrogen, The excitation power of the plasma of the said inert gas is 100 W or more and 12000 W or less, The manufacturing method of the photovoltaic device characterized by the above-mentioned. The method according to any one of claims 1 to 3, The inert gas comprises hydrogen, The flow rate of the hydrogen is 100 sccm or more 10000 sccm or less manufacturing method of a photovoltaic device. The method according to any one of claims 1 to 3, The holding time of the plasma of said inert gas is 10 second or more and 1 minute or less, The manufacturing method of the photovoltaic device characterized by the above-mentioned. Placing the substrate on a loading plate in the reaction chamber; Contacting a substrate placed on the loading plate with a substrate holder; Injecting source gas and doping gas and decomposing the same into plasma to form p-type silicon carbide on the substrate; Injecting an inert gas to remove static electricity between the substrate and the substrate holder to form a plasma of the inert gas; And Separating the substrate from the substrate holder Method of manufacturing a photovoltaic device comprising a. The method of claim 7, wherein Intrinsic silicon and n-type silicon are sequentially formed on the p-type silicon carbide, And forming a plasma of the inert gas after at least one of forming the intrinsic silicon or forming the n-type silicon. The method of claim 7, wherein Sequentially forming a buffer layer, intrinsic silicon, and n-type silicon on the p-type silicon carbide, And forming a plasma of the inert gas after at least one of forming the buffer layer, forming the intrinsic silicon, or forming the n-type silicon. The method according to any one of claims 7 to 9, The inert gas comprises hydrogen, The excitation power of the plasma of the said inert gas is 100 W or more and 12000 W or less, The manufacturing method of the photovoltaic device characterized by the above-mentioned. The method according to any one of claims 7 to 9, The inert gas comprises hydrogen, The flow rate of the hydrogen is 100 sccm or more 10000 sccm or less manufacturing method of a photovoltaic device. The method according to any one of claims 7 to 9, The holding time of the plasma of said inert gas is 10 second or more and 1 minute or less, The manufacturing method of the photovoltaic device characterized by the above-mentioned.

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