Synthesis, structure and optical properties of blue-emitting phosphor Sr4La(PO4)3O:Eu2+ for n-UV white-light-emitting diodes

A novel blue-emitting phosphor, Eu2+-activated Sr4La(PO4)3O phosphor was synthesized by conventional solid-state reaction method. This phosphor can be effectively excited by near-UV light in the range of 250–420 nm, which matches well with the emission of near ultraviolet LEDs. Under the excitation of 371 nm, the Sr4La(PO4)3O:0.05Eu2+ phosphor shows strong blue emission with the peak at 444 nm. The fluorescence decay curves the phosphor was discussed to verify the different emission center of Eu2+ ions. The critical Eu2+ quenching concentration (QC) mechanism was verified to be the dipole–dipole interaction. The temperature-dependent luminescence properties was investigated in detail. The luminescence characteristics indicates that this phosphor is a promising blue-emitting phosphor for white light emitting diodes.