LED용Mg2+·Ba2+Co-Doped Sr2SiO4:Eu 노란색 형광체의 발광특성 |
최경재, 지순덕1, 김창해, 이상혁1, 김호건2 |
한국화학연구소 화학소재연구부 1한국교원대학교 기술교육과 2한양대학교 응용화학과 |
Luminescence Characteristics of Mg2+·Ba2+ Co-Doped Sr2SiO4:Eu Yellow Phosphor for Light Emitting Diodes |
Kyoung-Jae Choi, Soon-Duk Jee1, Chang-Hae Kim, Sang-Hyuk Lee1, Ho-Kun Kim2 |
Advanced Materials Division, Korea Research Institute of Chemical Technology 1Department of Technology Education, Korea National University of Education 2Department of Applied Chemistry, Hanyang University |
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ABSTRACT |
An improvement for the efficiency of the $Sr_{2}SiO_{4}:Eu$ yellow phosphor under the $450{sim}470;nm$ excitation range have been achieved by adding the co-doping element ($Mg^{2+};and;Ba^{2+}$) in the host. White LEDs were fabricated through an integration of an blue (InGaN) chip (${lambda}_{cm}=450;nm$) and a blend of two phosphors ($Mg^{2+},;Ba^{2+};co-doped;Sr_{2}SiO_{4}:Eu$ yellow phosphor+CaS:Eu red phosphor) in a single package. The InGaN-based two phosphor blends ($Mg^{2+},;Ba^{2+};co-doped;Sr_{2}SiO_{4}:Eu$ yellow phosphor+CaS:Eu red phosphor) LEDs showed three bands at 450 nm, 550 nm and 640 nm, respectively. The 450 nm emission band was due to a radiative recombination from an InGaN active layer. This 450 nm emission was used as an optical transition of the $Mg^{2+},;Ba^{2+};co-doped;Sr_{2}SiO_{4}:Eu$ yellow phosphor+CaS:Eu red phosphor. As a consequence of a preparation of white LEDs using the $Mg^{2+},;Ba^{2+};co-doped;Sr_{2}SiO_{4}:Eu$ yellow phosphor+CaS:Eu red phosphor yellow phosphor and CaS:Eu red phosphor, the highest luminescence efficiency was obtained at the 0.03 mol $Ba^{2+}$ concentration. At this time, the white LEDs showed the CCT (5300 K), CRI (89.9) and luminous efficacy (17.34 lm/W). |
Key words:
Phosphor, LED (Light Emitting Diode), PL, Waite LED lamp |
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