CaWO4-Li2WO4-Eu2O3계 형광체의 PL 특성과 결정구조 |
김정석, 최진호, 정봉만1, 강현주2 |
호서대학교 디스플레이공학과 신소재공학과 1한국에너지기술연구원 전기조명연구센터 2삼척대학교 화학공학과 부설연구소 |
Luminescence Characteristics and Crystal Structure of CaWO4-Li2WO4-Eu2O3 Phosphors |
Jeong-Seog Kim, Jin-Ho Choi, Bong-Man Jeong1, Hyun-Ju Kang2 |
Department of Digital Display and Materials Engineering, Hoseo University 1Electrics and Lighting Research Center, KIER 2Research Institute of Chemical Engineering, Samcheok National University |
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ABSTRACT |
Photoluminescence (PL) and crystal structures of the $(l-x)CaWO_4-xLi_2WO_4$ binary system added with $Eu_2O_3$ activator have been characterized. The $CaWO_4;and;Li_2WO_4$ have the scheelite and phenakite structures respectively. The $CaWO_4-Li_2WO_4-Eu_2O_3$ phosphors show the red luminescence of 613 nm peak wavelength. The wavelength range of excitation spectral band is $380~470$ nm with the peak wavelength of 397 nm. The $0.88(0.5CaWO_4-0.5Li_2WO_4)-0.12Eu_2O_3$ showed the most superior luminescence characteristics. The effect of co-doping elements such as $Al_2O_3$ and rare-earth oxides on PL has been characterized. The co-doping elements deteriorated the luminescence intensity except the $Al_2O_3$ and $Gd_2O_3$. The PL characteristics of $CaWO_4-Li_2WO_4-Eu_2O_3$ phosphors have been compared to those of the alkali europium double molybdates (tungstates) of scheelite-related structure such as $LiEu(MoO_4)_2$ and $CsEu(MoO_4)_2$. The crystal structures of $(l-y)[(l-x)CaWO_4-xLi_2WO_4]-yEu_2O_3$ phosphors have been characterized using XRD data and rietveld refinement. |
Key words:
PL characteristics, Red luminescence, Crystal structure |
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