Studies on Ce3+ positions and photoluminescence properties of La1.45Ce0.05Ba3.5(SiO4)1.5(PO4)1.5F phosphor

In this paper, La1.45Ce0.05Ba3.5(SiO4)1.5(PO4)1.5F compound with apatite structure was synthesized via solid state reaction method. The phosphor exhibits two strong excitation bands at 279 nm and 345 nm in near ultraviolet light region. When excited at 345 nm, the emission peaks of the phosphor give a red-shift from 406 nm to 418 nm compared with that of 279 nm excitation. Besides, the site occupation of Ce3+ was proposed based on structure refinement, luminescence, fluorescence decay curves, as well as CIE diagram. All the results indicated that Ce3+ can occupy sites of La3+ with nine and seven coordination and a possible mechanism was proposed to explain the luminescence properties observed.