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Strong enhancement of 420∼425nm optical wavelength of blue LED by using CaF2 scintillating crystals as a cap

Published online by Cambridge University Press:  03 December 2012

Suzuka Nishimura
Affiliation:
Solartes Lab., 2009-3 Endo, Fujisawa, Kanagawa 2520816, Japan
Muneyuki Hirai
Affiliation:
Solartes Lab., 2009-3 Endo, Fujisawa, Kanagawa 2520816, Japan
Hiroshi Nagayoshi
Affiliation:
Tokyo National College of Technology, 1220-2 Kunugida-machi, Hachioji, Tokyo 193-8601, Japan
Kazutaka Terashima
Affiliation:
Department of Electrical and Electronic Engineering, Shonan Institute of Technology, 1-1-25 Tsujido Nishikaigan, Fujisawa, Kanagawa 251-8511, Japan
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Abstract

It has been found that the blue light emission of LED is remarkably enhanced by using optical window of CaF2 disk doped with Eu2O3. The CaF2 crystals doped with Eu2O3 strongly absorb UV light with 330~420nm optical wavelength as a cutting filter. Instead, CaF2 crystals emit 420~425nm wavelength visible light. As a result, the UV light shifts to a light of around 420nm wavelength, and the LED light emission intensity markedly increases. In our experiments, the UV components were absorbed, while, around 420nm emitting light has been strengthened by more than 30%. The FWHM value is improved by around 30%.

Type
Research Article
Copyright
Copyright © Materials Research Society 2012

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References

REFERENCES

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