SOLAR CELL AND METHOD OF MANUFACTURING THE SAME
Provided are a solar cell and a method of manufacturing the same. The solar cell includes a transparent substrate. A first electrode and a transparent insulating layer are sequentially stacked over a plurality of first regions of the transparent substrate. A first electrode, a light-converting layer, a transparent insulating layer, and a second electrode are sequentially stacked over a second region of the transparent substrate other than the first regions. Therefore, light incident from the substrate can penetrate between the light-converting layers spaced apart from each other, thus manufacturing a transparent solar cell. Also, since light scattered by the transparent insulating layer is also incident into the side of the light-converting layer, the light-receiving area is not reduced and thus the efficiency of the solar cell can be increased.
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The present invention relates to a solar cell and a method of manufacturing the same, and more particularly, to a transparent solar cell capable of transmitting light without reducing a light-receiving area and a method of manufacturing the same.
BACKGROUND ARTRecently, with the increase in concern about environmental problems and energy depletion, a solar cell is attracting an increasing attention as an alternative energy source that has abundant energy resources, has no environmental pollution problem, and has high energy efficiency. Solar cells can be classified into a solar heat cell and a solar light cell. The solar heat cell uses solar heat to generate steam necessary for rotating a turbine. The solar light cell uses semiconductor materials to convert solar light into electrical energy.
The solar light cell can be generally classified into a crystalline silicon solar cell and a thin film solar cell. The crystalline silicon solar cell includes a polycrystalline silicon solar cell and a single crystalline silicon solar cell. The thin film solar cell includes an amorphous silicon solar cell. However, since the crystalline silicon solar cell is manufactured using an expensive thick silicon substrate, the crystalline silicon solar cell has a limitation in reducing its thickness. Furthermore, since the silicon substrate is expensive, a price of the crystalline silicon solar cell becomes high.
What is thus being in the spotlight is the amorphous silicon solar cell that can be manufactured at a lot cost because it uses an inexpensive substrate such as a glass substrate and a metal substrate instead of an expensive silicon substrate and minimizes material consumption by depositing a thin film of several microns.
In comparison with the single crystalline silicon substrate or the polycrystalline silicon substrate, an amorphous-silicon thin film has a very short carrier diffusion length due to its inherent characteristics. Therefore, when forming a PN structure using the amorphous-silicon thin film, the efficiency of collecting electron-hole pairs may be very low. Thus, the amorphous silicon solar cell uses a light-converting layer of a PIN structure that has a highly-doped p-type amorphous silicon layer, a highly-doped n-type amorphous silicon layer, and an undoped i-type amorphous silicon layer inserted between the highly-doped p-type amorphous silicon layer and the highly-doped n-type amorphous silicon layer, and the amorphous silicon solar cell generally includes a first electrode, a PIN light-converting layer, and a second electrode, which are sequentially stacked over a substrate.
However, even when the amorphous silicon solar cell uses a transparent glass substrate, it fails to transmit light incident from the glass substrate since the amorphous silicon solar cell becomes opaque by the PIN light-converting layer and the electrodes are formed over the glass substrate. What is thus manufactured is a transparent solar cell as illustrated in
However, when the through hole 60 is formed from the bottom of the transparent substrate 10 to the predetermined region of the second substrate 50, the light-absorbing area is reduced and thus the efficiency of the solar cell is deteriorated.
DISCLOSURE OF INVENTION Technical ProblemThe present invention provides a transparent solar cell capable of transmitting light without deteriorating the efficiency thereof by not reducing a light-receiving area, and a method of manufacturing the same.
The present invention also provides a transparent solar cell capable of transmitting light without reducing a light-receiving area, and a method of manufacturing the same. To this end, light-converting layers are patterned, a transparent insulating layer is formed thinly, and an electrode is formed, so that light can penetrate between the light-converting layers and light can be incident also onto the sides of the light-converting layers.
Technical SolutionIn accordance with one aspect of the present invention, a solar cell includes: a transparent substrate; a first electrode and a transparent insulating layer that are sequentially stacked over a plurality of first regions of the transparent substrate; and a first electrode, a light-converting layer, a transparent insulating layer, and a second electrode that are sequentially stacked over a second region of the transparent substrate other than the first regions.
In accordance with another aspect of the present invention, a solar cell includes: a transparent substrate; a first electrode, a transparent insulating layer, and a second electrode that are sequentially stacked over a plurality of first regions of the transparent substrate; and a first electrode, a light-converting layer, a transparent insulating layer, and a second electrode that are sequentially stacked over a second region of the transparent substrate other than the first regions.
The first electrode may be formed of transparent conductive materials.
The light-converting layer may include a stack structure of a first semiconductor layer that is doped with first impurities, a second semiconductor layer that is not doped with impurities, and a third semiconductor layer that is doped with second impurities.
The transparent insulating layer may include a ZnO layer.
The ZnO transparent insulating layer may be formed to a thickness that provides the ZnO layer with tunneling and insulating characteristics.
The ZnO transparent insulating layer may be formed to a thickness of approximately 1000 Å or less.
In accordance with still another aspect of the present invention, a method of manufacturing a solar cell includes: forming a first electrode over a substrate; forming a light-converting layer over the first electrode and patterning the light-converting layer to form a plurality of patterned light-converting layers spaced apart from each other; forming a transparent insulating layer over the first electrode including the patterned light-converting layers; and forming a second electrode over the transparent insulating layer.
The light-converting layer may be patterned by a dry etching process using a gas obtained by mixing one of NF3, SF6, HBr, Cl2, BCl3 and a combination thereof with one of Ar, O2, He, N2 and a combination thereof.
The transparent insulating layer may be formed by depositing ZnO using a metal-organic chemical vapor deposition (MOCVD) process or a sputtering process.
The second electrode may be formed of silver to a thickness of approximately 500 Å or less using a sputtering process.
The second electrode may be formed of aluminum over the transparent insulating layer that is formed over the light-converting layer such that that the second electrode has a smaller pattern than the patterned light-converting layer.
Advantageous EffectsAs described above, the present invention forms the plurality of light-converting layers spaced apart from each other, forms the transparent insulating layer, and then forms the second electrode. Therefore, light incident from the substrate can penetrate between the light-converting layers, thus manufacturing a transparent solar cell. Also, since light scattered by the transparent insulating layer is incident also onto the sides of the light-converting layers, the light-receiving area is not reduced and thus the efficiency of the solar cell is increased.
Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.
Referring to
The substrate 110 may be a transparent substrate. Examples of the transparent substrate are a plate-shaped substrate and a sheet-shaped substrate that are formed of glass or transparent resin. A fine irregular structure may be formed in a surface of the substrate 110. The fine irregular surface structure of the substrate 110 can increase the absorption of incident light.
The first electrode 120 may be formed of transparent conductive materials such as indium tin oxide (ITO) and indium zinc oxide (IZO). Also, the first electrode 120 may have a fine irregular structure formed in a surface thereof.
The light-converting layer 130 is formed in plurality spaced apart from each other. Each of the light-converting layers 130 includes a plurality of semiconductor layers. For example, each of the light-converting layers 130 includes a stack of a p-type amorphous silicon layer 131, an i-type amorphous silicon layer 132, and an n-type amorphous silicon layer 133. Herein, the p-type amorphous silicon layer 131 is a layer that is doped with p-type impurities, the i-type amorphous silicon layer 132 is a layer that is not doped with impurities, and the n-type amorphous silicon layer 133 is a layer that is doped with n-type impurities. For example, the p-type amorphous silicon layer 131 is formed using B2H6 gas and SiH4 gas, the i-type amorphous silicon layer 132 is formed using H2 gas and SiH4 gas, and the n-type amorphous silicon layer 133 is formed using PH3 gas and SiH4 gas. Also, the p-type amorphous silicon layer 131 is formed to a thickness of approximately 100 Å to approximately 200 Å, the i-type amorphous silicon layer 132 is formed to a thickness of approximately 4000 Å to approximately 5000 Å and the n-type amorphous silicon layer 133 is formed to a thickness of approximately 500 Å to approximately 700 Å. When light is incident on the i-type amorphous silicon layer 132 of the light-converting layer 130, each of stable electron-hole pairs in the i-type amorphous silicon layer 132 is discomposed by photons to generate an electron and a hole. The generated electron and the hole are respectively transferred through the n-type amorphous silicon layer 133 and the p-type amorphous silicon layer 131 to the second electrode 150 and the first electrode 120. The transfer of the electron and the hole generates photovoltaic power that becomes the electrical energy of the solar cell.
The transparent insulating layer 140 is formed over the resulting structure including the light-converting layers 130. Thus, the transparent insulating layer 140 is also formed over the sidewalls of the light-converting layers 130 to insulate the light-converting layers 130. The transparent insulating layer 140 may be formed to a thickness that allows the tunneling of electrons passing through the n-type amorphous silicon layer 133. For example, the transparent insulating layer 140 may include a ZnO layer. The ZnO layer is an n-type semiconductor material when not doped with impurities, and has insulating characteristics when having a small thickness of approximately 1000 Å or less. Thus, using the ZnO layer, the transparent insulating layer 140 is formed to a thickness of approximately 1000 Å or less, which can allow the tunneling and have insulating characteristics.
The second electrode 150 is formed in a smaller pattern than the light-converting layer 130, over the transparent insulating layer 140 that is formed over the light-converting layer 130. The received light quantity increases as the second electrode 150 is formed smaller than the light-converting layer 130. The second electrode 150 is formed in plurality spaced apart from each other. The second electrode 150 is formed mainly of metal, for example, aluminum (Al).
The solar cell in accordance with the first embodiment includes: a plurality of first regions where the first electrode 120 and the transparent insulating layer 140 are stacked over the substrate 110; and a plurality of second regions where the first electrode 120, the light-converting layer 130, the transparent insulating layer 140, and the second electrode 150 are stacked over the substrate 110. The solar cell can transmit light incident from the bottom surface of the substrate 110 through the first region, so that it possible to embody a transparent solar cell. Herein, the distance between the first electrode 120 and the second electrode 150 in the first region is greater than the distance between the first electrode 120 and the second electrode 150 in the second region. Also, since incident light is scattered by the transparent insulating layer 140 and thus light is absorbed also onto the side of the light-converting layer 130, the light-receiving area is not reduced and thus it possible to increase the efficiency of the solar cell.
Referring to
The cluster equipment may change in configuration. For example, although it has been described that the light-converting layer 130 is formed using the second, third and fourth process chambers 300, 400 and 500, the light-converting layer 130 may be formed by using one of the second, third and fourth process chambers 300, 400 and 500 and controlling process gas that flows into the process chamber. Also, the chambers may change in arrangement. Also, the cluster equipment may further include: a deposition device for depositing a photoresist layer; an exposure/development device for patterning the photoresist layer; an ashing device for removing the photoresist layer; and a cleaning device.
Referring to
Referring to
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It has been described that the light-converting layer 130 is formed using the second, third and fourth process chambers 300, 400 and 500. However, the layers constituting the light-converting layer 130 may be continuously formed by using one of the second, third and fourth process chambers 300, 400 and 500 and controlling process gas that flows into the process chamber. Also, if a PECVD chamber is used as the seventh process chamber 800 in which the metal layer is formed, the seventh process chamber 800 may be replaced with the process chamber used to form the light-converting layer 130.
Referring to
The substrate 110 may be a transparent substrate that is formed of glass or transparent resin. The substrate 110 may have a fine irregular structure formed in a surface thereof, thus increasing the absorption of incident light.
The first electrode 120 may be formed of transparent conductive materials such as indium tin oxide (ITO) and indium zinc oxide (IZO). Also, the first electrode 120 may have a fine irregular structure formed in a surface thereof.
The light-converting layer 130 is formed in plurality spaced apart from each other. Each of the light-converting layers 130 includes the stack of the p-type amorphous silicon layer 131 that is doped with p-type impurities, the i-type amorphous silicon layer 132 that is not doped with impurities, and the n-type amorphous silicon layer 133 that is doped with n-type impurities.
The transparent insulating layer 140 is formed on the entire surface of the region including the light-converting layers 130. For example, the transparent insulating layer 140 is formed using a ZnO layer to a thickness of approximately 1000 Å or less that can allow a tunneling operation and insulating characteristics.
The second electrode 150 is formed to cover the transparent insulating layer 140. For example, the second electrode 150 is formed of silver (Ag) to a thickness of approximately 500 Å or less. In this case, the second electrode 150 can transmit light while serving as an electrode.
As described above, the solar cell in accordance with the second embodiment includes: a plurality of first regions where the first electrode 120, the transparent insulating layer 140, and the second electrode 150 are stacked over the substrate 110; and a plurality of second regions where the first electrode 120, the light-converting layer 130, the transparent insulating layer 140, and the second electrode 150 are stacked over the substrate 110. The solar cell can transmit light incident from the bottom surface of the substrate 110 through the first region, thus making it possible to embody a transparent solar cell that can transmit light. Herein, the distance between the first electrode 120 and the second electrode 150 in the first region is greater than the distance between the first electrode 120 and the second electrode 150 in the second region. Also, incident light is scattered by the transparent insulating layer 140 and thus light is also absorbed onto the side of the light-converting layer 130. Therefore, the light-receiving area is not reduced, resulting in increasing the efficiency of the solar cell.
Referring to
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Although the solar cell and the method of manufacturing the same have been described with reference to the specific embodiments, they are not limited thereto. Therefore, it will be readily understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the present invention defined by the appended claims.
Claims
1. A solar cell, comprising:
- a transparent substrate;
- a first electrode and a transparent insulating layer that are sequentially stacked over a plurality of first regions of the transparent substrate; and
- a first electrode, a light-converting layer, a transparent insulating layer, and a second electrode that are sequentially stacked over a second region of the transparent substrate other than the first regions.
2-20. (canceled)
21. The solar cell of claim 1, wherein the transparent insulating layer is formed to have a thickness that allows tunneling and insulating characteristics.
22. The solar cell of claim 21, wherein the transparent insulating layer is further formed over a sidewall of the light-converting layer.
23. The solar cell of claim 22, wherein the transparent insulating layer is continuously formed over an upper surface and the sidewall of the plurality of light-converting layers which is spaced apart from each other.
24. The solar cell of claim 23, wherein the transparent insulating layer is formed using ZnO.
25. The solar cell of claim 1, wherein the second electrode is formed to have a thickness capable of transmitting light and functioning as an electrode.
26. The solar cell of claim 1, wherein light incident onto the sidewalls of the light-converting layer is received to the solar cell.
27. The solar cell of claim 26, further comprising an insulating layer that is formed over the sidewall of the light-converting layer and scatters the incident light for the light to be absorbed to the sidewall of the light-converting layer.
28. A solar cell, comprising:
- a transparent substrate;
- a first electrode, a transparent insulating layer, and a second electrode that are sequentially stacked over a plurality of first regions of the transparent substrate: and
- a first electrode, a light-converting layer, a transparent insulating layer, and a second electrode that are sequentially stacked over a second region of the transparent substrate other than the first regions.
29. The solar cell of claim 28, wherein the transparent insulating layer is formed to have a thickness that allows tunneling and insulating characteristics.
30. The solar cell of claim 29, wherein the transparent insulating layer is further formed over a sidewall of the light-converting layer.
31. The solar cell of claim 30, wherein the transparent insulating layer is continuously formed over an upper surface and the sidewall of the plurality of light-converting layers which is spaced apart from each other.
32. The solar cell of claim 31, wherein the transparent insulating layer is formed using ZnO.
33. The solar cell of claim 28, wherein the second electrode is formed to have a thickness capable of transmitting light and functioning as an electrode.
34. The solar cell of claim 28, wherein light incident onto the sidewalls of the light-converting layer is received to the solar cell.
35. The solar cell of claim 34, further comprising an insulating layer that is formed over the sidewall of the light-converting layer and scatters the incident light for the light to be absorbed to the sidewall of the light-converting layer.
36. The solar cell of claim 28, wherein the second electrode of the first region is formed of aluminum or silver.
37. A method of manufacturing a solar cell, the method comprising:
- forming a first electrode over a substrate;
- forming a light-converting layer over the first electrode and patterning the light-converting layer to form a plurality of patterned light-converting layers that are spaced apart from each other;
- forming a transparent insulating layer over the first electrode including the patterned light-converting layers: and
- forming a second electrode over the transparent insulating layer.
38. The method of claim 37, wherein the transparent insulating layer is formed by depositing ZnO using a MOCVD (Metal-Organic Chemical Vapor Deposition) process or a sputtering process
39. The method of claim 37, wherein the second electrode is formed of a metallic material using a PECVD (Plasma-Enhanced Chemical Vapor Deposition) process or sputtering process, and formed to have a thickness capable of transmitting light and functioning as an electrode.
40. The method of claim 39, wherein the second electrode is formed using silver or aluminum such that the second electrode has a smaller pattern than the patterned light-converting layer.
41. The method of claim 37, wherein the first electrode, the light-converting layer, the transparent insulating layer and the second electrode are formed in separate chambers, respectively, or continuously formed in the same chamber by controlling input gas.
42. The method of claim 41, wherein the same chamber is a PECVD (Plasma-Enhanced Chemical Vapor Deposition) chamber.
43. The method of claim 37, wherein the transparent insulating layer is further formed over a sidewall of the light-converting layer.
44. The method of claim 43, wherein the transparent insulating layer is continuously formed over an upper surface and the sidewall of the plurality of light-converting layers which is spaced apart from each other.
45. The method of claim 37, wherein light incident onto the sidewall of the light-converting layer is received to the solar cell.
46. The method of claim 45, further comprising forming an insulating layer over the sidewall of the light-converting layer to scatter the incident light such that the light is absorbed to the sidewall of the light-converting layer.
Type: Application
Filed: Jul 10, 2008
Publication Date: Aug 5, 2010
Applicant: JUSUNG ENGINEERING CO., LTD. (Gyeonggi-Do)
Inventors: Jin Hong (Gyeonggi-Do), Jae Ho Kim (Gyeonggi-Do), Chang Sil Yang (Gyeonggi-Do)
Application Number: 12/668,420
International Classification: H01L 31/00 (20060101); H01L 31/0232 (20060101); H01L 31/18 (20060101);