Enhanced Luminescence Efficiency for Bi, Eu Doped Y2O3 Red Phosphors for White LEDs
Bi and Eu co-doped Y2O3 was used as a red phosphor with a very high efficiency synthesized by the solid state reaction and co-precipitation The emission spectrum consisted of a weak band at 581, 587, 593 and 599 nm corresponding to the 5D0 → 7F1 transition, with sharp peaks of maximum intensity occurring at about 611 nm due to the 5D0 → 7F2 transition of Eu3+. In addition, the excitation spectrum exhibited a broad band between 250 and 550 nm with peaks occurring at about 310 – 400 nm and a sharp peak at 465.5 nm. The relative emission intensity was improved by co-precipitation synthesis as compared to solid state reaction synthesis. This implies that an appropriate co-precipitation synthesis could improve the luminescent efficiency, particularly for the samples prepared with the optimized firing temperature of 1100 °C.
Byung Tae Ahn, Hyeongtag Jeon, Bo Young Hur, Kibae Kim and Jong Wan Park
W.J. Park et al., "Enhanced Luminescence Efficiency for Bi, Eu Doped Y2O3 Red Phosphors for White LEDs", Solid State Phenomena, Vols. 124-126, pp. 379-382, 2007