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 ) MoO 4 : x Eu 3+ , y Bi 3+ , z R + (R +   =   Li + , Na + , and K + ) phosphors are prepared through solid-state reaction method in air. Eu 3+ doped SrMoO 4 phosphor can show red emission at ∼616   nm under excitation 275   nm and 397   nm light due to the 5 D 0   →   7 F 2 transition of Eu 3+ ion, and its emission intensity can be enhanced after co-doping Bi 3+ owing to energy transfer between Bi 3+ and Eu 3+ ions. The mechanism of energy transfer is discussed by the schematic energy level diagrams of Bi 3+ and Eu 3+ ions. The optimal composition in Eu 3+ and Bi 3+ co-doped SrMoO 4 phosphors is determined to be (Sr 0.92 Eu 0.05 Bi 0.03 )MoO 4 . The emission intensity of SrMoO 4 :Eu 3+ , Bi 3+ 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.