Microwave Assisted Sintering of Thermally Stable BaMgAl10O17:Eu2+ Phosphors

Eu2+ doped BaMgAl10O17:Eu2+ (BAM) phosphors suffer from serious instability, although they have been widely used in various lighting and display applications. In this paper, high thermally stable Si–N-codoped BAM phosphors have been prepared by the microwave assisted sintering method at a relatively low temperature of 1450°C, and they were synthesized at 1550°C by the conventional solid-state reaction method for comparison. The microwave assisted sintering could reduce the activation energy and thus enhance the diffusion rate, and greatly improve the substitution amount of Si–N pairs for Al–O ones in the BAM host lattice. The Si–N doping significantly increased both the photoluminescence and the thermal stability of the BAM phosphors under ultraviolet (UV) and vacuum ultraviolet (VUV) excitations, comparable to the samples prepared by the conventional solid state reaction method. The proposed method is expected to be potentially applicable to other phosphors with higher photoluminescence and stability.