TWI487131B - Apparatus and method for making solar cell - Google Patents

Description

Solar cell manufacturing equipment and method of manufacturing same

The present invention relates to an apparatus and method for fabricating a solar cell, and more particularly to an apparatus and method for fabricating a solar cell having a flexible substrate.

The solar cell mainly uses the photoelectric conversion principle, and a typical structure thereof mainly includes a substrate and a P-type semiconductor material layer and an N-type semiconductor material layer disposed on the substrate.

Photoelectric conversion refers to the process by which the radiant energy photons of the sun are converted into electrical energy by semiconductor materials (see "Grown junction GaAs solar cell", Shen, CC; Pearson, GL; Proceedings of the IEEE, Volume 64, Issue 3, March 1976 Page. (s): 384-385). When sunlight hits the semiconductor, a portion of it is reflected off the surface and the remainder is absorbed or transmitted by the semiconductor. Some of the absorbed light, of course, becomes thermal energy, while other photons collide with the valence electrons that make up the semiconductor, producing electron-hole pairs. Thus, the light energy is converted into electrical energy in the form of electron-hole pairs, and a barrier electric field is formed on both sides of the P-type and N-type interfaces, driving electrons to the N region, and holes are driven toward the P region, thereby making N There is excess electrons in the region, and there are excess holes in the P region, and a photo-generated electric field opposite to the electric field of the barrier is formed in the vicinity of the PN junction. A portion of the photogenerated electric field, in addition to offsetting the barrier electric field, also positively charges the P-type layer, the N-type semiconductor layer is negatively charged, and a thin layer between the N region and the P region produces a so-called photovoltaic electromotive force. If metal leads are soldered to the P-type layer and the N-type semiconductor layer, respectively, and the load is turned on, the external circuit passes current. So formed One battery element, connected in series and in parallel, can generate a certain voltage and current, and output power.

In recent years, solar cells have been widely used in aerospace, industrial, meteorological and other fields. How to apply solar cells to daily life to solve problems such as energy shortage and environmental pollution has become a hot issue. Among them, the combination of solar cells and building materials, so that the future of large buildings or family houses to achieve self-sufficiency in electricity, is a major development direction in the future, Germany, the United States and other countries have proposed photovoltaic roofing plans.

However, the substrates of general solar cells are made of single crystal germanium, polycrystalline germanium or glass. These materials are not easily deflected and are difficult to fix on a curved surface, which limits the shape and mounting position of the solar cell panel, especially when it is desired to There are often many limitations when applied to modules that are combined with building materials.

In view of the above, it is necessary to provide an apparatus for a solar cell having a flexible substrate and a method of fabricating the same.

An apparatus for manufacturing a solar cell, comprising a winding chamber and a coating chamber. The winding chamber is provided with a take-up reel for winding a flexible polymer substrate and for discharging the polymer substrate from the discharge reel, and a take-up reel for the coated polymer The substrate is rolled up. a coating chamber is sequentially provided with a first sputtering region, a first deposition region, a second sputtering region, a second deposition region, a third sputtering region and a fourth sputtering region, each of which is provided with at least one roller The first end of the deflectable polymer substrate is wound on the take-up reel, and the second end of the polymer substrate is sequentially wound on the take-up reel through the rollers, so that the polymer substrate can pass through the reel A sputtering zone, a first deposition zone, a second sputtering zone, a second deposition zone, a third sputtering zone, and a fourth sputtering zone are wound around the take-up reel. The first sputtering region is configured to form the back electrode on one surface of the polymer substrate by a sputtering method, and the first deposition region is configured to form the P-type semiconductor layer on the back electrode by chemical vapor deposition a second sputtering region for forming the PN junction layer on the P-type semiconductor layer by a sputtering method, the second deposition region for forming the N-type semiconductor on the PN junction layer by chemical vapor deposition a layer, the third sputtering region is configured to form the transparent conductive layer on the N-type semiconductor layer by a sputtering method, and the fourth sputtering region is configured to form the front electrode on the transparent conductive layer by a sputtering method, Thereby the solar cell is obtained.

A manufacturing method for manufacturing a solar cell using the above apparatus, the method comprising the steps of: winding one end of a polymer substrate on a take-up reel, starting from a reel of the other end of the polymer substrate, and sequentially passing the first guide shaft Winding on the take-up reel through the roller and the second guide shaft; releasing the polymer substrate from the reel, in the unwinding process, the polymer substrate is sequentially passed through the first sputtering zone, the first deposition a second sputtering region, a second deposition region, a third sputtering region, and a fourth sputtering region, wherein the back is formed on one surface of the polymer substrate by sputtering in the first sputtering region An electrode, wherein the P-type semiconductor layer is formed on the back electrode by chemical vapor deposition in the first deposition region, and the PN junction layer is formed on the P-type semiconductor layer by sputtering in the second sputtering region, Forming the N-type semiconductor layer on the PN junction layer by chemical vapor deposition in the second deposition region, and forming the transparent conductive layer on the N-type semiconductor layer by sputtering in the third sputtering region, The fourth sputtering zone is sputtered The front electrode is formed on the transparent conductive layer to obtain the solar cell.

The substrate of the solar cell of the present invention is a flexible polymer base relative to the prior art The solar cell can be flexed. When it is applied to the construction field, it is easier to design the solar cells with different geometric shapes in accordance with the shape of the building itself, so that the design is more flexible.

10‧‧‧ solar cells

101‧‧‧Substrate

102‧‧‧ Back electrode

103‧‧‧P type semiconductor layer

104‧‧‧P-N layer

105‧‧‧N type semiconductor layer

106‧‧‧Transparent conductive layer

107‧‧‧ front electrode

1012‧‧‧ Surface of the substrate

20‧‧‧Roll coating system

202‧‧‧Winding room

204‧‧‧ Coating room

206‧‧‧Reel

208‧‧‧Reel

210‧‧‧roller

212‧‧‧guide shaft

2041‧‧‧First sputtering zone

2042‧‧‧First sedimentary zone

2043‧‧‧Second sputtering zone

2044‧‧‧Second sedimentary zone

2045‧‧‧3rd sputtering zone

2046‧‧‧4th sputtering zone

1 is a schematic cross-sectional view of a solar cell according to an embodiment of the present invention; and FIG. 2 is a cross-sectional view showing a roll coating system for manufacturing a solar cell according to an embodiment of the present invention.

The invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1, a solar cell 10 includes a substrate 101 having a surface 1012. The surface 1012 of the substrate 101 is sequentially formed with a back metal contact layer 102 and a P-type semiconductor layer 103. The PN junction layer 104, the N-type semiconductor layer 105, the Transparent Conductive Oxide 106, and the Front Metal Contact Layer 107.

The substrate 101 is a flexible polymer sheet (Polymer Foil). The polymer can be transparent or opaque. The transparent polymer material may be polycarbonate (Polycarbonate, PC), polymethyl methacrylate (PMMA) or the like. The opaque polymer material may be Polyether Ether Ketone (PEEK), Liquid Crystal Polymer (LCP) or the like. Preferably, the material of the substrate 101 is an optical grade polymer such as PMMA. The thickness of the substrate 101 is approximately between 10 μm and 100 μm.

The material of the back electrode 102 may be silver (Ag), copper (Cu), molybdenum (Mo), aluminum (Al), copper-aluminum alloy (Cu-Al Alloy), silver-copper alloy (Ag-Cu Alloy), or copper-molybdenum. Alloy (Cu-Mo Alloy) and the like. The back electrode 102 may be formed by a sputtering method or a deposition method.

The material of the P-type semiconductor layer 103 may be a P-type Amorphous Silicon (Pa-Si) material, in particular, a P-Type Amorphous Silicon With Hydrogen (Pa-Si). :H) Material. Of course, the material of the P-type semiconductor layer may also be a III-V compound or a II-VI compound, especially a semiconductor material doped with aluminum (Al), potassium (Ga), or indium (In), such as aluminum nitride. Potassium (AlGaN) or aluminum gallium arsenide (AlGaAs).

Preferably, the material of the P-type semiconductor layer 103 is a P-type amorphous germanium material. The amorphous germanium material absorbs light about 500 times stronger than the crystalline germanium material, so the thickness of the semiconductor layer made of the amorphous germanium material is much smaller than that of the crystalline germanium material when the photon absorption amount is the same. The thickness of the layer. And the amorphous germanium material has lower requirements on the material of the substrate. Therefore, the use of an amorphous germanium material not only saves a large amount of material, but also makes it possible to fabricate a large-area solar cell (the area of the crystalline germanium solar cell is limited by the size of the germanium wafer).

The material of the PN junction layer 104 may be a combination of a group III-V compound or a group I-III-VI compound, such as cadmium telluride (CdTe), copper indium selenide (CuInSe2), or copper indium gallium. Selenium (CuIn1-XGaSe2, CIGS). The P-N junction layer 132 is used to convert photons into electron-hole pairs and form a barrier electric field. The P-N junction layer 132 can be formed by a method such as Chemical Vapor Deposition (CVD), sputtering, or the like.

The material of the N-type semiconductor layer 105 may be an N-type amorphous germanium (N type amorphous Silicon, abbreviated as N-a-Si) material, especially N-type amorphous silicon with hydrogen (N-a-Si:H) material. Of course, the material of the N-type semiconductor layer 133 may also be a III-V compound or a II-VI compound, especially a semiconductor material doped with nitrogen (N), phosphorus (P), or arsenic (As), such as nitriding. Potassium (GaN) or indium gallium phosphide (InGaP).

The material of the transparent conductive layer 106 may be, for example, Indium Tin Oxide (ITO), zinc oxide (ZnO), or the like.

The material of the front electrode 107 may be silver (Ag), copper (Cu), molybdenum (Mo), aluminum (Al), copper-aluminum alloy (Cu-Al Alloy), silver-copper alloy (Ag-Cu Alloy), or copper-molybdenum. Alloy (Cu-Mo Alloy) and the like.

Compared with the prior art, the substrate 101 of the solar cell 10 of the present invention is a flexible polymer sheet, so that the solar cell 10 can be flexed, and when it is applied to the construction field, it is easier to design different geometries according to the shape of the building itself. The shape of the solar cell makes the design more flexible. Moreover, the price of the polymer sheet is relatively inexpensive, so that the cost of the solar cell 10 can be reduced, which is advantageous for further widespread promotion of the solar cell 10. In addition, the solar cell 10 of the present invention can be applied not only to the construction field but also to 3C products such as spacecraft, vehicles, and mobile phones due to its flexibility and low cost.

An apparatus and method for manufacturing a solar cell 10 are described below.

Referring to FIG. 2, the roll coating system 20 includes a winding chamber 202 and a coating chamber 204. A take-up reel 206 and a take-up reel 208 are disposed in the winding chamber 202.

The coating chamber 204 includes, in order from left to right, a first sputtering zone 2041, a first deposition zone 2042, a second sputtering zone 2043, a second deposition zone 2044, a third sputtering zone 2045, and a fourth sputtering. Shot area 2046.

The first sputtering region 2041, the second sputtering region 2043, the third sputtering region 2045, and the fourth sputtering region 2046 are respectively used to form the back electrode 102, the PN junction layer 104, and the transparent conductive layer of the solar cell by a sputtering method. 106 and front electrode 107. In the present embodiment, the sputtering method is preferably a direct current magnetron sputtering method (Direct Current Magnetron Sputtering). The sputtering targets (not shown) of the respective sputtering zones are selected according to different materials. For example, for the first sputtering region 2041, the sputtering target may be silver, copper, molybdenum, aluminum, copper aluminum alloy, silver copper alloy, or copper molybdenum alloy, etc., depending on the material of the back electrode 102 to be formed.

The first deposition region 2042 and the second deposition region 2044 are used to form the P-type semiconductor layer 103 and the N-type semiconductor layer 105 of the solar cell 10 by chemical vapor deposition (CVD), respectively. In the present embodiment, the deposition method is preferably plasma enhanced chemical vapor deposition (Plasma Enhanced Chemical Vapor Deposition).

At least one roller 210 is disposed in each of the sputtering zone and the deposition zone, and the roller 210 is used to support the substrate 101 to be coated. In the present embodiment, a cooling liquid (not shown) may be disposed in the roller 210 to facilitate heat dissipation of the substrate 101 so as to maintain a relatively low temperature throughout the entire coating process. A guide shaft 212 is disposed between the winding chamber 202 and the coating chamber 204, and the guide shaft 212 is used to guide the substrate 101 to be coated to advance.

A method of manufacturing a solar cell using the roll coating system 20 is as follows:

Before the coating, the substrate 101 to be coated is wound between the take-up reel 206, the guide shaft 212, the roller 210, and the take-up reel 208, and the substrate 101 is a polymer sheet. The structure of the back electrode 102 and the like is sequentially formed by plating on the surface 1012 of the substrate 101, thereby obtaining solar energy. Battery 10.

When the motor (not shown) drives the take-up reel 206 to rotate clockwise, the guide shaft 212 and the roller 210 rotate counterclockwise, and the take-up reel 208 rotates clockwise. The substrate 101 from the take-up reel 206 passes through the guide shaft 212 to the first sputtering zone 2041. The roller 210 cools the substrate 101 and maintains its temperature at a suitable temperature, and performs sputtering in the first sputtering zone 2041. The back electrode 102 is formed on the surface 1012 of the substrate 101.

The take-up reel 208 continues to drive the substrate 101 forward, the portion of the substrate 101 having the back electrode 102 reaches the first deposition zone, the roller 210 cools the substrate 101 and maintains its temperature at a suitable temperature, and plasma assists in the first deposition zone 2042 The P-type semiconductor layer 103 is formed on the back electrode 102 by chemical vapor deposition.

The take-up reel 208 continues to drive the substrate 101 forward, and the portion of the substrate 101 having the back electrode 102 and the P-type semiconductor layer 103 reaches the second sputtering region 2043, and the roller 210 cools the substrate 101 and maintains its temperature at a suitable temperature. The second sputtering region is sputtered to form a PN junction layer 104 on the P-type semiconductor layer 103.

A portion of the substrate 101 having the back electrode 102, the P-type semiconductor layer 103, and the PN junction layer 104 sequentially passes through the second deposition region 2044, the third sputtering region 2045, and the fourth sputtering region 2046, and sequentially forms an N-type semiconductor layer 105, The transparent conductive layer 106 and the front electrode 107 are used to obtain the solar cell 10 shown in FIG.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

20‧‧‧Roll coating system

202‧‧‧Winding room

204‧‧‧ Coating room

206‧‧‧Reel

208‧‧‧Reel

210‧‧‧roller

212‧‧‧guide shaft

2041‧‧‧First sputtering zone

2042‧‧‧First sedimentary zone

2043‧‧‧Second sputtering zone

2044‧‧‧Second sedimentary zone

2045‧‧‧3rd sputtering zone

2046‧‧‧4th sputtering zone

Claims (2)

A manufacturing apparatus for manufacturing a solar cell, comprising: a winding chamber provided with a discharge reel and a take-up reel for winding a flexible polymer substrate and the polymer substrate from the reel Release, the take-up reel is used to roll up the coated polymer substrate; a coating chamber is sequentially provided with a first sputtering zone, a first deposition zone, a second sputtering zone, a second deposition zone, and a third sputtering And a fourth sputtering zone, each of which is respectively provided with at least one roller, the first end of the deflectable polymer substrate is wound on the discharge reel, and the second end of the polymer substrate sequentially passes the at least one roller The shaft is wound on the take-up reel so that the polymer substrate can pass through the first sputtering zone, the first deposition zone, the second sputtering zone, the second deposition zone, the third sputtering zone, and the fourth sputtering in this order from the take-up reel An emitter region, thereby being wound on the take-up reel, the first sputtering region for forming the back electrode on one surface of the polymer substrate by sputtering, the first deposition region being used for chemical vapor deposition Formed on the back electrode a P-type semiconductor layer, the second sputtering region is for forming the PN junction layer on the P-type semiconductor layer by a sputtering method, and the second deposition region is formed on the PN junction layer by a chemical vapor deposition method The N-type semiconductor layer, the third sputtering region is for forming the transparent conductive layer on the N-type semiconductor layer by a sputtering method, and the fourth sputtering region is formed on the transparent conductive layer by a sputtering method The front electrode, thereby obtaining the solar cell. A method of manufacturing a solar cell using the manufacturing apparatus as described in claim 1, the method comprising the steps of: winding one end of a polymer substrate on a take-up reel, and winding the other end of the polymer substrate through a roller On the take-up reel; releasing the polymer substrate from the take-up reel so that the polymer substrate passes through the first sputtering zone in sequence, a first deposition region, a second sputtering region, a second deposition region, a third sputtering region, and a fourth sputtering region, wherein the first sputtering region is sputtered on one surface of the polymer substrate Forming the back electrode, forming the P-type semiconductor layer on the back electrode by chemical vapor deposition in the first deposition region, and forming the PN on the P-type semiconductor layer by sputtering in the second sputtering region a junction layer, the N-type semiconductor layer is formed on the PN junction layer by chemical vapor deposition in the second deposition region, and the transparent conductive layer is formed on the N-type semiconductor layer by sputtering in the third sputtering region And forming a front electrode on the transparent conductive layer by sputtering in the fourth sputtering region, thereby obtaining the solar cell.