Color-tunable luminescence properties and energy transfer of Tb3+/Sm3+ co-doped Ca9La(PO4)5(SiO4)F2 phosphors

The Ca9La(PO4)5(SiO4)F2:Tb3+,Sm3+ phosphor with apatite structure has been successfully synthesized by high temperature solid-state reaction, and its luminescence properties as well as energy transfer mechanism has been investigated in detail. The energy transfer (ET) efficiency increases with increasing Sm3+ doping content, that was confirmed by the luminescence spectra and fluorescence decay curves of corresponding ions. The ET interaction mechanism was determined to be dipole-quadrupole interaction. The emission color of Ca9La(PO4)5(SiO4)F2:Tb3+,Sm3+ phosphor could be adjusted from green (0.272, 0.489) to yellow (0.363, 0.395) area through controlling the dopant ratio of Tb3+/Sm3+. The above results indicate that the Ca9La(PO4)5(SiO4)F2:Tb3+,Sm3+ phosphor has a great potential in white light-emitting diodes application.