Tunable luminescence properties and energy transfer of Ba3NaLa(PO4)3F:Tb3+,Sm3+ phosphors with apatite structure

Abstract

Tb3+–Sm3+ co-doped Ba3NaLa(PO4)3F phosphors with apatite structure have been prepared by a high temperature solid-state reaction, and their luminescence properties have been investigated in detail. The energy transfer (ET) mechanism was verified as the dipole–quadrupole mechanism, and the ET efficiency as well as the critical distance is also estimated. As a result of fine-tuning of the emission composition of the Tb3+ and Sm3+ ions, tunable luminescence properties can be realized by combining the emission of Tb3+ and Sm3+ in a single host lattice under UV light excitation. The emission color of the obtained phosphors can be modulated from green to yellow by controlling the doping content of the Sm3+ ions with the fixed Tb3+ content. Additional, as the temperature increases from RT to 150°C, the PL intensities of Ba3NaLa0.7(PO4)3F:0.10Tb3+,0.20Sm3+ decreased to 80.4% and 78.6% of the initial PL intensity, corresponding to the intensity of transition of Sm3+ and transition of Tb3+ in the Ba3NaLa0.7(PO4)3F:0.10Tb3+,0.20Sm3+ phosphor, respectively. These results indicate the series of Ba3NaLa1−x−y(PO4)3F:xTb3+,ySm3+ phosphors can be acted as a good candidate for the application in white light-emitting diodes.