Synthesis and Luminescence of Lu3(Al,Si)5(O,N)12:Ce3+ Phosphors

Si 4+ -N 3-was incorporated into Ce 3+ -doped lutetium aluminum garnet (Lu 2.965 Ce 0.035 Al 5 O 12 , LuAG:Ce 3+ ) lattices, resulting in the formation of Lu 2.965 Ce 0.035 Al 5-x Si x O 12-x N x [(Lu,Ce)AG:xSN]. For x = 0-0.25, the synthesized powders consisted of the LuAG single phase, and the lattice constant decreased owing to the smaller Si 4+ ions. However, for x > 0.25, a small amount of unknown impurity phases was observed, and the lattice constant increased. Under 450 nm excitation, the PL spectrum of LuAG:Ce 3+ exhibited the green band, peaking at 505 nm. The incorporation of Si 4+ -N 3-into the Al 3+ -O 2-sites of LuAG:Ce 3+ led to a red-shift of the emission peak wavelength from 505 to 570 nm with increasing x. Corresponding CIE chromaticity coordinates varied from the green to yellow regions. These behaviors were discussed based on the modification of the 5d 1 split levels and crystal field surroundings of Ce 3+ , which arose from the Ce-(O,N)8 bonds.