Warm white light generation from a single phased phosphor Sr10[(PO4)5.5(BO4)0.5](BO2):Eu2+, Mn2+, Tb3+ for light emitting diodes

A novel single phased white light emitting phosphor Sr-10[(PO4)(5.5)(BO4)(0.5)](BO2):Eu2+, Mn2+, Tb3+ was synthesized by solid-state reaction for the first time. The crystal structure, photoluminescence properties and the efficient energy transfer from different Eu2+ sites to Mn2+ and Tb3+ in Sr-10[(PO4)(5.5)(BO4)(0.5)](BO2) is studied in detail by X-ray diffractometry Rietveld method, luminescence spectra, energy-transfer efficiency and lifetimes. Through effective energy transfer, the wavelength-tunable warm white light can be realized with superior chromaticity coordinates of (0.37, 0.30) and low correlated color temperature (CCT = 3512 K) by coupling the emission bands peaking at 410, 542 and 649 nm attributed to the contribution from Eu2+, Tb3+ and Mn2+, respectively. The results indicate the white phosphor Sr-10[(PO4)(5.5)(BO4)(0.5)](BO2):Eu2+, Mn2+, Tb3+ can serve as a promising material for phosphor-converted warm white LEDs.