Synthesis and luminescence properties of Sr(1-x-y-z)MoO4:xEu3+, yBi3+, zR+ (R+ = Li+, Na+, and K+) phosphors

A series of Sr(1-x-y-z)MoO4:xEu(3+,) yBi(3+), zR(+) (R+ = Li+, Na+, and K+) phosphors are prepared through solid-state reaction method in air. Eu3+ doped SrMoO4 phosphor can show red emission at similar to 616 nm under excitation 275 nm and 397 nm light due to the D-5(0) -> F-7(2) transition of Eu3+ ion, and its emission intensity can be enhanced after co-doping Bi3+ owing to energy transfer between Bi3+ and Eu3+ ions. The mechanism of energy transfer is discussed by the schematic energy level diagrams of Bi3+ and Eu3+ ions. The optimal composition in Eu3+ and Bi3+ co-doped SrMoO4 phosphors is determined to be (Sr0.92Eu0.05Bi0.03)-MoO4. The emission intensity of SrMoO4:Eu3+, Bi3+ phosphor is found to be further improved by using Li+, Na+, and K+ ions as charge compensators. These experiment results in the paper are helpful to develop novel and high-efficiency phosphors for white light-emitting diodes. (C) 2014 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.