Tunable emission and efficient energy-transfer properties of Ce3+ and Mn2+ co-doped Ba3Gd(PO4)3 phosphors

The tunable emission color phosphors Ba3Gd(PO4)(3): Ce3+, Mn2+ were synthesized by conventional high-temperature solid-state reaction method. The photoluminescence properties and energy transfer (ET) of the Ce3+ and Mn2+ co-doped Ba3Gd(PO4)(3) phosphors were studied systematically. Through an efficient energy-transfer process, the obtained phosphors show both dual-emission including a ultraviolet (UV) to blue emission originating from Ce3+ and a reddish-orange emission from Mn2+ under UV excitation (similar to 310 nm) with considerable intensity. When the Ce3+ doping content is fixed at 0.05, the emission color tone can be adjusted from blue through reddish-purple and ultimately to red region by tuning the contents of Mn2+ from 0.01 to 0.5. The critical distance between Ce3+ and Mn2+ was calculated to be 12.23 angstrom. The concentration quenching of Mn2+ was experimentally found to be 0.3. The energy-transfer efficiency was discussed and the ET mechanism between Ce3+ and Mn2+ ions was proved to be dipole-dipole interaction. The Ce3+ and Mn2+ co-doped Ba3Gd(PO4)(3) phosphors are potential UV-convertible candidates in UV white-light LEDs for the energy transfer from Ce3+ to Mn2+ ions.