Synthesis and luminescence properties of LiBaPO4:Bi3+ yellow-emitting phosphor for solid-state lighting

Novel LiBaPO4:Bi3+ yellow-emitting phosphor is synthesized by high temperature solid-state reaction method in air. With excitation 260 nm, LiBaPO4:Bi3+ phosphor emits yellow light with the chromaticity coordinate (0.4272, 0.4657) and color rendering index 77.7. Emission band peaking at similar to 588 nm of LiBaPO4:Bi3+ phosphor in the range of 400-790 nm is attributed to the (3) P (1) -> (1) S (0) electron transition of Bi3+ ion. Excitation band monitored at 588 nm in the range of 220-300 nm is assigned to the (1) S (0) -> (3) P (1) electron transition of Bi3+ ion. The optimal Bi3+ ion concentration in LiBaPO4:Bi3+ phosphor is similar to 1.0 mol%. Time resolved spectra and fluorescence lifetime data confirm that there is only Bi3+ ion luminous center in LiBaPO4:Bi3+ phosphor. The luminous mechanism is analyzed by configurational coordinate diagram of Bi3+ ion. The experiment results are helpful to develop other new Bi3+-doped optical materials for solid-state lighting.