Luminescence Properties of Rare-Earth Doped α-SiAlONs
Rare-earth doped Ca-α-SiAlON phosphors, with the compositions of (Ca1-3/2xREx)m/2Si12-m-nAlm+nOnN16-n (RE = Ce, Sm, Eu, Tb, Yb and Dy, 0.5 ≤ m = 2n ≤ 3.0), were prepared by reaction at 1700oC for 2h under 10 atm N2. The concentration of rare earths varied from 3 to 30 at% with respect to Ca. The photoluminescence properties of the powders were investigated at room temperature. The results show that (i) strong visible emissions are observed in rare-earth doped Ca-α-SiAlONs; (ii) the emission properties can be optimized by tailoring the activator concentration and the composition of the α-SiAlON host crystal; and (iii) the yellow Eu2+-doped Ca-α-SiAlON phosphors can be used in warm white LEDs.
T. Ohji, T. Sekino and K. Niihara
R. J. Xie et al., "Luminescence Properties of Rare-Earth Doped α-SiAlONs", Key Engineering Materials, Vols. 317-318, pp. 797-802, 2006