Synthesis, energy transfer and luminescence properties of KSrVO4:Eu3+ red phosphor

Abstract

KSrVO4:Eu3+ phosphors are synthesized by solid-state reaction method in air. Host KSrVO4 under excitation at 345 nm emits green–yellow light with the CIE chromaticity coordinates (0.3466, 0.4425), and its broad emission band peaking at ~545 nm covers the range 400–750 nm due to 3T1,2 → 1A1 transitions in [VO4]3− group. KSrVO4:Eu3+ phosphor under excitation at 315 and 394 nm shows red emission with the CIE chromaticity coordinates (0.6279, 0.3717), and the emission spectra in the range of 560–750 nm contains four narrow emission bands owing to 5D0 → 7FJ (J = 1, 2, 3, and 4) transitions of Eu3+ ion, respectively. The optimal Eu3+ doping concentration is ~4 mol%. The lifetime decreases from 0.991 to 0.893 ms with increasing Eu3+ concentration within the range 0.5–6 mol%. The possible luminous mechanism is analyzed by the simplified energy level diagrams of VO43− group and Eu3+ ion, and energy transfer process in KSrVO4:Eu3+ phosphor. The experimental results indicate that KSrVO4:Eu3+ phosphor will be possible to be used as red phosphor candidate for white light-emitting diode (LED) based on ultraviolet (~315 nm) and near ultraviolet (~395 nm) LED chips.