Tunable emission, energy transfer and charge compensation in Sr3(VO4)2:Sm3+,P5+,Na+ phosphor

Abstract

A series of Sr3(VO4)2:Sm3+,P5+,Na+ phosphors are synthesized by using solid-state reaction method in air. The strongest emission band peaking at ∼600nm is assigned to the 4G5/2→6H7/2 transition of Sm3+ ion, and the strong excitation peak at ∼402nm due to 6H5/2→4F7/2 transition indicates that these phosphors can be excited by near ultraviolet light emitting diode chip. Energy transfer (ET) between VO43− group and Sm3+ ion can be observed. Sr3(VO4)2:Sm3+ phosphor with excitation 320nm exhibits a systematically varied hues from green to yellow by changing Sm3+ ion concentration from 0 to 6mol%. The luminous mechanism of Sr3(VO4)2:Sm3+ phosphor is explained by using the energy level diagrams of VO43− group and Sm3+ ion. The luminescence properties of Sr3(VO4)2:Sm3+ phosphor can be improved and tuned by codoping the P5+ and Na+ ions due to ET and charge compensation. Lifetimes of Sr2.925Sm0.05(VO4)2, Sr2.925Sm0.05(V0.9P0.1O4)2, and Sr2.9Na0.05Sm0.05(V0.9P0.1O4)2 phosphors are 1.208, 1.219, and 0.796ms, respectively. The experiment results are helpful to adjust the luminescence properties of Sm3+-doped other phosphors.