A direct warm-white-emitting Sr3Sc(PO4)3:Eu2+, Mn2+ phosphor with tunable photoluminescence via efficient energy transfer.

A broadband direct warm-white-emitting phosphor Sr3Sc(PO4)3:Eu(2+), Mn(2+) (SSP:Eu(2+), Mn(2+)) was prepared by a solid-state reaction. The powder X-ray diffraction data, photoluminescence spectra, fluorescence decay curves, quantum efficiency, and chromaticity coordinates of the obtained phosphors were measured and discussed in detail. The results reveal that there is efficient energy transfer from the Eu(2+) to the Mn(2+) ions and the broadband direct warm-white-light comes from the emissions of the Eu(2+) and Mn(2+) ions. The possible energy transfer mechanism was proposed in terms of the experimental results and analysis. We demonstrate the ability to tune the color tone, the correlated color temperature (CCT), and the chromaticity coordinates which can approach the color properties required for solid state lighting. The developed phosphors can be efficiently excited in the UV region and exhibit a warm-white-light emission, making them attractive as single-component white-light-emitting conversion phosphors for UV-based white light emitting diodes.