KR100848451B1 - Solar cell manufacturing method of wire shape - Google Patents

Abstract

The surface of the p-type silicon is made of n-type semiconductor by diffusion or the like, and one side is ground to derive the p-type semiconductor region, and then the surface electrode is formed by silk screen, inkjet printing or vacuum deposition. After welding with solder ball on the electrode wiring printed on the lower substrate surface, it is made by inserting a reflector-shaped aluminum sheet or plastic film coated with aluminum into the wire shape. Simplification and large area of the manufacturing process can be easily realized.

Solar cell, silicon, wire, reflector

Description

Solar cell manufacturing method of wire shape

1 is a longitudinal sectional view of a wire-shaped solar cell having an opening of an n-type semiconductor layer according to an embodiment of the present invention;

Figure 2 is a bottom view of the solar cell of Figure 1,

3 is a longitudinal cross-sectional view of a wire-shaped solar cell including a first electrode and a second electrode according to an embodiment of the present invention;

4 is a bottom view of the solar cell of FIG. 3;

5 is a plan view showing a step of forming a first electrode wiring, a second electrode wiring, and an electrical insulation layer according to an embodiment of the present invention;

FIG. 6 is a cross-sectional view of a process of welding the first electrode and the second electrode at the cross-section taken along the line C-D of FIG.

7 is a sectional view of the reflector inserted according to an embodiment of the present invention;

8 is a schematic view of a wire-shaped solar cell according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

1: p-type semiconductor 2: n-type semiconductor

3: n-type semiconductor 4: opening of p-type semiconductor

5: second electrode 6: first electrode

11: reflector 12: lower substrate

13: electrical insulation layer 21: first electrode wiring

22: second electrode wiring 23: first electrode bus bar

24: second electrode busbar 25: solder ball

26: second electrode wiring welding portion 27: first electrode wiring welding portion

28: upper substrate

The present invention relates to a solar cell for converting solar energy into electrical energy. Fossil fuels, such as petroleum and coal, which are mostly used as human energy sources for a long time, cause global warming due to carbon dioxide resulting from their use, and in the case of nuclear power generation, there are no unexpected accidents or the danger of radiation even during normal operation. And other problems. On the other hand, solar cells using sunlight as an energy source have very little influence on the global environment, and a wide range of applications are expected. However, in the present state, there are some problems that hinder the practical use of such solar cells. Conventional solar cells have used a lot of single crystal or polycrystalline silicon. Silicon single crystals require a lot of energy and time for crystal growth, and silicon single crystals are used in the form of wafers to fabricate solar cells. First, silicon raw materials are placed in a crucible and then melted by applying a heat source to grow ingots in a crystal growth furnace. In order to make a semiconductor wafer using the grown silicon ingot, it has to go through various processes. For example, a cylindrical process, a slicing process, a polishing process, a lapping process, etc. are mentioned. The amount of silicon discarded through this process is about 50% or more based on the ingot. So, making a solar cell using a silicon wafer is expensive. Besides these problems, it is difficult to mass-produce silicon wafers due to the high cost of crystal growth equipment and wafer processing equipment, making it difficult to supply them at low cost.

 In the case of silicon solar cells, the supply shortage of cells and modules and the rise in silicon wafer prices are increasing. As a way to make cheaper solar cells, there are attempts to manufacture solar cells using spherical solar cells and thin films. However, spherical silicon solar cells are difficult to manufacture, and large-area solar cells require a large number of spherical elements to reduce costs. Although a solar cell using a thin film can realize a large area, there are disadvantages in that photoelectric conversion efficiency decreases over time because a large number of crystal defects exist in a semiconductor.

In the present invention, to solve this problem, it is intended to make a wire-shaped silicon solar cell using a round wire-shaped silicon. The present invention relates to a method of manufacturing a wire-shaped silicon solar cell, and more particularly, to a wire-shaped silicon solar cell that can obtain a high efficiency solar cell at low cost. The present invention relates to a wire-shaped solar cell and a method of manufacturing the same. The wire-shaped p-type semiconductor is used to form a wire-shaped p-type semiconductor. After the p-type semiconductor region is derived, the surface electrode is formed by silkscreen, inkjet, or vacuum deposition method, and the surface of the lower substrate on which the wiring is drawn is welded with solder balls or paste, and then a reflector-shaped aluminum thin film or aluminum is deposited. The solar cell is manufactured by sandwiching a plastic film between wires.

The present invention is to solve the problems as described above, the object is to manufacture a high efficiency solar cell with improved efficiency at a low process cost.

Another object of the present invention is to simplify the manufacturing process by more easily forming the electrode of the wire-shaped silicon and inserting a reflector to help the concentration of light into the space between the wires.

The present invention relates to a silicon solar cell manufacturing method,
The silicon is extracted from the molten silicon in the form of a wire through a nozzle, the wire is a p-type semiconductor, the phosphor surface (P) is diffused on the wire surface to form an n-type semiconductor layer on the wire surface pn junction device Exposing a portion of the p-type semiconductor by polishing the surface of the pn junction element, forming a first electrode in the p-type semiconductor exposed portion, and forming a second electrode in the n-type semiconductor opening; Forming a first electrode wiring and a second electrode wiring on a substrate, applying an electrical insulating layer, and welding the pn junction element to the first electrode wiring of the lower substrate with the first electrode, and the second electrode wiring being second Welding the electrode and welding the pn junction element by applying a temperature to the electrical insulation layer. It consists of a.

Hereinafter, a method of manufacturing a wire-shaped silicon solar cell according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a longitudinal cross-sectional view of a wire-shaped solar cell having an opening of an n-type semiconductor layer according to an embodiment of the present invention. First, wire-like silicon is made into a long stick. Usually, the diameter of the wire-shaped silicon can be produced from about several micro (μm) to several millimeters (mm), but about 1mm in diameter is preferred. If the diameter is less than 0.05mm, it is difficult to construct the device, and if the diameter is 5mm or more, the amount of silicon used increases, which increases the manufacturing price. This wire-shaped silicon can be produced by heating a p-type polycrystalline silicon particle containing a trace amount of boron until melting, and pulling it out in a long wire form through a circular nozzle while gradually cooling it. Various shapes can also be manufactured by changing the shape of a nozzle. For example, the shape of the nozzle is angled to create a polygonal nozzle, which is then used. In detail, hexagonal nozzles or octagonal nozzles can be used to form hexagonal rods or octagonal rod-shaped crystals. The preferred shape for making a solar cell is circular. This can be used by cutting to a suitable size to fit the size of the solar cell device to make the wire-shaped silicon manufactured as described above. After cutting to an appropriate size of a few centimeters (cm) size, a p-type junction device is manufactured by forming an n-type semiconductor (2) layer on the surface of the p-type semiconductor (1). For example, as the diffusion source, POCl ₃ or P ₂ O ₅ is heat-treated at a temperature of 800 to 900 ° C. for 10 to 30 minutes to diffuse the doping concentration to 100 to 200 μs / sq. Usually, the junction thickness of the n-type semiconductor 2 layer is about 0.5 to 1 mu m.

In the above embodiment, a solar cell device using a wire-shaped p-type semiconductor 1 and having an n-type semiconductor 2 layer formed on the surface thereof is made. It may be a semiconductor device in which boron is diffused to form a p-type semiconductor layer. The p-type semiconductor layer may be formed by a method such as an ion implantation method or a vapor phase chemical vapor deposition method (CVD) even if it is not a method of diffusion.

As described above, after the n-type semiconductor 2 is formed on the surface of the p-type semiconductor 1, the opening 3 of the n-type semiconductor is formed, and the exposed portion 4 of the p-type semiconductor is manufactured from the opening. do. As a method, there exists a method of grinding and removing a part of wire-like elements by methods, such as grinding. 1 and 2 show a wire-shaped device processed by the above method, Figure 1 is a longitudinal cross-sectional view, Figure 2 is a bottom view respectively. Opening part 3 of an n-type semiconductor in which the wire-shaped p-type semiconductor 1 surface is covered with n-type semiconductor 2 and partially cut by grinding to form a rectangular shape. And the exposed portion 4 of the p-type semiconductor.

In the above embodiment, a wire-shaped pn junction silicon element is exemplified, but a compound semiconductor, a single crystal, a polycrystal, and an amorphous material may be used. The pin type, the metal-insulator-semiconductor (MIS) form, and other structures which form an insulating layer at the interface between the p-type semiconductor layer and the n-type semiconductor layer may be used.

3 is a longitudinal cross-sectional view of a wire-shaped solar cell including a first electrode and a second electrode according to an embodiment of the present invention. 4 is a bottom view thereof.

The wire-shaped device made in FIG. 2 is coated with silver / aluminum ink on the exposed portion 4 of the p-type semiconductor using a method such as an ink jet method, and then dried to form a first electrode 6. . In some cases, aluminum may be applied first, and then silver / aluminum may be applied again. Silver ink is applied to the opening 3 of the n-type semiconductor, dried, and then the second electrode 5 is formed. Firing of the electrode is usually carried out for several seconds to several tens of minutes at a temperature of 700 to 950 ° C. The first electrode 6 and the second electrode 5 may be fired sequentially or simultaneously.

5 is a plan view showing a step of forming the first electrode wiring, the second electrode wiring, and the electrical insulation layer according to the embodiment of the present invention. As the lower substrate 12, a nonconductive plate such as glass, a conductive metal plate, or a plastic can be used. Non-conductive plates, such as glass and plastics, are formed on the first electrode wirings 21, the first electrode busbars 23, the second electrode wirings 22, and the second electrode busbars using conductive ink thereon. 24) After printing, dry it and fire it. When using an electrically conductive metal plate, an electrical insulation layer is formed thereon by a method such as vacuum deposition or screen printing, and then electrical wiring is formed in the same manner as described above. There are various kinds of conductive ink materials, but silver or silver / aluminum ink is used here. The first electrode wiring 21, the first electrode busbar 23, the second electrode wiring 22, and the second electrode are formed on the lower substrate manufactured by the above embodiment by screen printing. It is applied to the part except the bus bar 24. The electrical insulation layer 13 can be comprised with the coating layer of a thermoplastic resin, a hot melt adhesive, or an adhesive. The material of the electric thermal insulation layer is polycarbonate, acrylic resin, acetal resin, polyamide, polyimide, polyacrylsulfone, polyphenylene sulfide and Chlorinated polyethers can be used. Usually, a wire-like element can be joined by thermal fusion or ultrasonic fusion at a temperature of 150 to 350 ° C. FIG. 6 illustrates the arrangement of a plurality of wire-like elements in the CD cross-section of FIG. 5, followed by the first electrode wiring 21 and the second electrode wiring 22 for the first electrode 6 and the second electrode 5, respectively. It is sectional drawing which shows the process of welding. At this time, the solder ball 25 may be used or it may be welded using a conductive paste. Welding may be performed at both ends of the wire-shaped device, or may be welded by inserting a solder ball 25 in the middle of the wire-shaped device. After welding the electrode and the wiring, the temperature is applied to the electrical insulation layer to fuse a plurality of wire-like elements.

7 is a sectional view in which a reflector according to an embodiment of the present invention is inserted. By inserting the reflector 11 as shown in Figure 7 to the device completed in Figure 6 is to produce a wire-shaped solar cell. The reflector serves to help the concentration of light is made of a structure that is sandwiched between the wire-shaped device after making the shape of the reflector (11) by pressing the deposition of aluminum on the plastic film. Such a reflector may be used after being taken with a press using metals such as aluminum or copper.

 8 is a schematic diagram of a completed wire-shaped solar cell. The upper substrate 28 is for preventing the reflector 11 and the wire-shaped solar cell elements from contamination. An anti-reflection film may be coated on the upper substrate 28 to increase the efficiency of the solar cell.

As described above, the wire-shaped solar cell manufacturing method according to the present invention has a simple process so that the silicon consumption is low compared to the conventional method using the wafer, while the solar cell has high efficiency, low cost, and large area. Do.

Claims (9)

In the silicon solar cell manufacturing method, The silicon is extracted from the molten silicon in the form of a wire through a nozzle, the wire is a p-type semiconductor, the phosphor surface (P) is diffused on the wire surface to form an n-type semiconductor layer on the wire surface pn junction device Exposing a portion of the p-type semiconductor by polishing the surface of the pn junction element, forming a first electrode in the p-type semiconductor exposed portion, and forming a second electrode in the n-type semiconductor opening; Forming a first electrode wiring and a second electrode wiring on a substrate, applying an electrical insulating layer, and welding the pn junction element to the first electrode wiring of the lower substrate with the first electrode, and the second electrode wiring being second Welding the electrode and welding the pn junction element by applying a temperature to the electrical insulation layer. The wire-shaped silicon solar cell manufacturing method according to claim 1, wherein the wire-shaped silicon diameter is 0.05 to 5.0 mm. The method of manufacturing a wire-shaped silicon solar cell according to claim 1, further comprising inserting a reflector to increase the concentration of light. The method of manufacturing a wire-shaped silicon solar cell according to claim 1, wherein the electrode material, the electrode wiring material or the welding material is at least one selected from silver or aluminum. In the silicon solar cell manufacturing method, The silicon is a molten silicon extracted in the form of a wire through a polygonal nozzle, the polygon is a p-type semiconductor, the phosphor surface (P) is diffused on the polygon surface to form an n-type semiconductor layer on the wire surface p-junction Forming a device, exposing a portion of the p-type semiconductor by polishing the surface of the pn junction element, forming a first electrode in the p-type semiconductor exposed portion, and forming a second electrode in the n-type semiconductor opening; Forming a first electrode wiring and a second electrode wiring on the lower substrate, applying an electrical insulating layer, and welding the pn junction element to the first electrode wiring of the lower substrate with the first electrode; Welding the second electrode, applying the temperature to the electrical insulating layer to fusion the pn junction element, and inserting a reflector between the polygons. A method of manufacturing a polygonal-shaped silicon solar cells, The method of claim 5, wherein the polygonal silicon has a diameter of 0.05 to 5.0 mm. delete The method of claim 5, wherein the electrical insulation layer is polycarbonate, acrylic resin, acetal resin, polyamide, polyimide poly acryl sulfone, polyphenylene sulfide ( Polyphenylene sulfide) and chlorinated polyether (poly ether) at least one selected from the silicon solar cell manufacturing method characterized in that delete

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