액상법을 이용한 구상의 Sr4Al14O25:Eu2+ 형광체의 합성 및 발광 특성
Preparation and Luminescence Properties of Spherical Sr4Al14O25:Eu2+ Phosphor Particles by a Liquid Synthesis
이정(고려대학교); 남산(고려대학교); 최성호(한국화학연구원); 정하균(한국화학연구원)
24권 7호, 351~356쪽
초록
A spherical Sr4Al14O25:Eu2+ phosphor for use in white-light-emitting diodes was synthesized using a liquid-statereaction with two precipitation stages. For the formation of phosphor from a precursor, the calcination temperature was1,100 oC. The particle morphology of the phosphor was changed by controlling the processing conditions. The synthesizedphosphor particles were spherical with a narrow size-distribution and had mono-dispersity. Upon excitation at 395 nm, thephosphor exhibited an emission band centered at 497 nm, corresponding to the 4f65d→4f7 electronic transitions of Eu2+. The critical quenching-concentration of Eu2+ in the synthesized Sr4Al14O25:Eu2+ phosphor was 5 mol%. A phosphorconvertedLED was fabricated by the combination of the optimized spherical phosphor and a near-UV 390 nm LED chip. When this pc-LED was operated under various forward-bias currents at room temperature, the pc-LED exhibited a brightblue-green emission band, and high color-stability against changes in input power. Accordingly, the prepared sphericalphosphor appears to be an excellent candidate for white LED applications.
Abstract
A spherical Sr4Al14O25:Eu2+ phosphor for use in white-light-emitting diodes was synthesized using a liquid-statereaction with two precipitation stages. For the formation of phosphor from a precursor, the calcination temperature was1,100 oC. The particle morphology of the phosphor was changed by controlling the processing conditions. The synthesizedphosphor particles were spherical with a narrow size-distribution and had mono-dispersity. Upon excitation at 395 nm, thephosphor exhibited an emission band centered at 497 nm, corresponding to the 4f65d→4f7 electronic transitions of Eu2+. The critical quenching-concentration of Eu2+ in the synthesized Sr4Al14O25:Eu2+ phosphor was 5 mol%. A phosphorconvertedLED was fabricated by the combination of the optimized spherical phosphor and a near-UV 390 nm LED chip. When this pc-LED was operated under various forward-bias currents at room temperature, the pc-LED exhibited a brightblue-green emission band, and high color-stability against changes in input power. Accordingly, the prepared sphericalphosphor appears to be an excellent candidate for white LED applications.
- 발행기관:
- 한국재료학회
- 분류:
- 재료공학