Aerosol Flame Deposition 법을 이용한 백색 LED용 CaAl12O19:Mn4+ 적색 형광체의 발광 특성에 관한 연구

Abstract

CaAl12O19:Mn4+ red phosphors were synthesized by Aerosol Flame Deposition and solid state reaction, and the basic luminescence characteristics were compared. The major photoluminescence peak of CaAl12O19:Mn4+ phosphors synthesized by Aerosol Flame Deposition were observed at 660nm, while those synthesized by solid state reaction was observed at 643nm and 656nm and 667nm. The maximal photoluminescence intensity showed in the powder heat-treated at 1100 ℃ due to spherical particle shape and smooth surface even though the crystallinity was not fully developed. The emission intensity of the CaAl12O19:Mn4+ powders with various Mn doping concentration exhibited the maximum intensity at 0.12 mol% Mn. The effect of an activator Mg2+ on the photoluminescence intensity of CaAl12O19:Mn4+ phosphor was also studied. The 0.15 mol% Mg2+ ions doped sample exhibited maximum PL intensity, approximately 2 times higher than un-doped sample. Although the absolute intensity of photoluminescence was slightly lower for the phosphor synthesized by Aerosol Flame Deposition than solid state reaction, both phosphor powders exhibited the identical lifetime in transient decay of photoluminescence, suggesting that the luminescence quantum efficiencies are identical and the difference in absolute photoluminescence intensity is originated from particle size effect.