Lu3(Al,Si)5(O,N)12:Ce3+ phosphors with broad emission band and high thermal stability for white LEDs.

A yellow-orange emitting Lu 3 Al 5− x Si x O 12− x N x :Ce 3+ phosphor with excellent color rendering, high luminescent efficiency and high thermal stability was reported in this paper. It was synthesized by a conventional solid-state reaction method. The effect of Si 4+ –N 3− incorporation on the optical properties of Lu 3 Al 5 O 12 :Ce 3+ phosphor was investigated and compared to YAG:Ce 3+ with the same compositions. Similarly, the addition of α-Si 3 N 4 leads to a distinct redshift and broadening of photoluminescent spectrum, which is assigned to the increased covalency and crystal field strength caused by N 3− . Nevertheless, an excellent thermal stability and a higher integrated intensity presented by α-Si 3 N 4 -doped LuAG:Ce 3+ are distinctive. Further, the emission intensity can be greatly enhanced by adding NaF flux. Finally, the white LED flat lamp with a CRI as high as 83 and a luminous efficiency of 85 lm/W is successfully realized by using a single LuAG-based oxynitride phosphor combined with a blue LED chip, which is completely feasible for general indoor illuminations to replace the traditional fluorescent or incandescent lamps. [ABSTRACT FROM AUTHOR]