Photoluminescence properties of Ce3+ and Mn2+-activated Ba9Sc2Si6O24 phosphor for white light emitting diodes

A single-phased silicate compound (Ba1-xCex)(9)(Sc1-yMny)(2)Si6O24 was prepared by solid-state reaction at high temperature. From powder X-ray diffraction (XRD) analysis, the formation of Ba9Sc2Si6O24 with an R3 space group was confirmed. In the photoluminescence spectra under ultraviolet (UV) ray excitation, the Ba9Sc2Si6O24:Ce3+, Mn2+ phosphor emits two distinctive color light bands: a blue one originating from Ce3+ and a red one caused by Mn2+. The energy transfer process from Ce3+ to Mn2+ was confirmed, the critical radius as well as the transfer efficiency was calculated, and the energy transfer mechanism was discussed. In addition, the decay-time testing indicates that the energy transfer efficiencies from Ce(1) to Mn2+ and Ce(2) to Mn2+ are different. The emission chromaticity of Ba9Sc2Si6O24:Ce3+, Mn2+ phosphor could be tuned from blue to red by altering the Ce3+/Mn2+ concentration ratio.