자외선 여기용 청색 및 황색 형광체의 발광특성 |
최경재, 박정규, 김경남, 김창해, 김호건1 |
한국화학연구원 화학소재연구부 1한양대학교 응용화학과 |
Luminescence Characteristics of Blue and Yellow Phosphor for Near-Ultraviolet |
Kyoung-Jae Choi, Joung-Kyu Park, Kyung-Nam Kim, Chang-Hae Kim, Ho-Kun Kim1 |
Advanced Materials Division, Korea Research Institute of Chemical Technology 1Department of Applied Chemistry, Hanyang University |
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ABSTRACT |
We have synthesized a $Eu^{2+}-activated;Sr_3MgSi_2O_8$ blue phosphor and $(Sr,Ba)_2SiO_4$ yellow phosphor and prepared white LEDs by combining these phosphors with a InGaN UV LED chip. Three distinct emission bands from the InGaN-based LED and the two phosphors are clearly observed at 405 nm, 460 nm and at around 560 nm, respectively. The 405 nm emission band is due to a radiative recombination from a InGaN active layer. This blue emission was used as an optical transition of the $Sr_3MgSi_2O_8:Eu$ blue phosphor and $(Sr,Ba)_2SiO_4:Eu$ yellow phosphor. The 460 nm and 560 nm emission band is ascribed to a radiative recombination of $Eu^{2+}$ impurity ions in the $Sr_3MgSi_2O_8:Eu$ and $(Sr,Ba)_2SiO_4$ host matrix. As a consequence of a preparation of UV White LED lamp using the $Sr_3MgSi_2O_8:Eu$ blue phosphor and $(Sr,Ba)_2SiO_4:Eu$ yellow phosphor, the highest luminescence efficiency was obtained at the ration of epoxy/two phosphor (1/0.2361). At this time, the CIE chromaticity was CIE x = 0.3140, CIE y = 0.3201 and CCT (6500 K). |
Key words:
Phosphor, LED(Light Emitting Diode), PL, UV white LED lamp |
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