Luminescence properties and structure of Eu2+ doped KMgPO4 phosphor

Eu2+-doped KMgPO4 was prepared by high temperature solid-state reaction. The phase formation was confirmed by X-ray powder diffraction measurement. Photoluminescence excitation spectrum measurements show that the phosphor can be efficiently excited by near UV light from 230 to 400 nm and presents a dominant luminescence band centered at 470 nm due to the 4f65d1→4f7 transition of Eu2+ ions at room temperature. The influence of temperature on the luminescence and decay times were investigated. There are two distinct Eu2+ sites in KMgPO4 lattices, which present different luminescence and lifetimes. The assignments of the Eu2+ sites were discussed on the base of the luminescence properties and the structure of KMgPO4 crystal. The unusual increase of the decay time of the 4f65d emission in KMgPO4 from 10 K to room temperature was reported.