2000 Fiscal Year Final Research Report Summary
Conversion Efficiency of Solar Cell with Ion-Implanted Rare Earth into Anti-Reflection Film
| Project/Area Number |
10555089
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
電力工学・電気機器工学
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| Research Institution | The University of Electro-Comunications |
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Principal Investigator |
KAWANO Katsuyasu Univ.Electro-Commun., Faculity of Electro-Communications, Professor, 電気通信学部, 教授 (90017418)
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| Project Period (FY) |
1998 – 2000
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| Keywords | Rare Earth / Ion Implantation / Antireflection Film / Eu^<2+> / Solar Cell / Photovoltaic Precursor / Conversion Efficiency / Spectroscopic Sensitivity |
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| Research Abstract |
On studies of solar cell efficiency improvements performed so far, almost all researches have aimed to modify the structures of solar cell itself for fitting the spectroscopic sensitivity to the sunlight spectrum that is absolutely unchangeable. A reversed concenption, however, is there that the sunlight spectrum is modified to be fitted to solar cell sensitivity by applying wavelength shifting operation of rare earth ions. By applying wavelength shifting operation of rare earth ions as photovoltaic precursors, the higher energy region of sunlight can be shifted to a longer wavelength, in which the cells can produde electric power with high efficiency. The most effective rare earth Eu^<2+> ions were doped by the ion implantation techniques into the anti-reflection (AR) film that is usually coated on the surface of a solar cell. Two kinds of commercial a-Si and p-Si solar cells with SiO_2 AR films which the ion-implantation doses were 10^<11>-10^<12> /cm^2 were implanted under the ion beam energy of 180 keV.The relative conversion efficiencies, the ratios of after- to before-implanted, were found to be 1.55 to 1.58. For p-Si cell, on the other hand, lower relative efficiency may be owing to less reachings of emission to the spectroscopic sensitivity region than the case of a-Si one. Also some assisting mechanisms for sunlight concentrations such as lenses, prisms and texture systems may be required.
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