Photoluminescence, energy transfer, color tunable properties of Sr3La(BO3)3:Ce, Tb phosphors

A series of blue-green color tunable Sr3La(BO3)3:Ce, Tb phosphors were prepared via a solid-state reaction method. The characterizations of X-ray diffraction (XRD), photoluminescence properties, the diffuse reflectance spectra (DRS), the decay curves, energy transfer mechanism and color tunable properties were investigated in detail. As Ce3+ ions single doped in Sr3La(BO3)3, the phosphor presents intense light blue under n-UV excitation. As for Sr3La(BO3)3:Ce, Tb, with the increase of the concentration of Tb3+, the emission intensity of Tb3+ characteristic wavelength increased and that of Ce3+ deceased at the same time. By comparing the decay curves of Sr3La(BO3)3:0.03Ce, y Tb, the results indicated that energy transfer existed between Ce3+ and Tb3+, the energy transfer efficiency reached 91.57% when y = 0.5. The energy transfer mechanism from Ce3+ to Tb3+ in Sr3La(BO3)3 was demonstrated to be dipole-quadrupole and the critical distance was calculated to be 7.6295 Å∼10.1741 Å by Dexter's energy transfer theory. Those results indicated that the color tunable Sr3La(BO3)3:Ce, y Tb phosphors can be a potential green-emitting candidate for w-LEDs under n-UV.