Site occupancy and tunable photoluminescence properties of Eu2+-Activated Ba3Sc(BO3)3 phosphors for white light emitting diodes

A series of emission-tunable Ba3-xSc(BO3)(3): xEu(2+)(0 <= x <= 0.15) and Ba2.97-yGdySc1-yMgy(BO3)(3): 0.03Eu(2+)(0 <= y <= 0.15) phosphors were synthesized by a solid-state method. Structure analysis of X-ray powder diffraction (XRD) and Rietveld refinement show that Eu2+ ions occupy randomly at Ba sites of hexagonal lattice with space group P6(3)cm. Photoluminescence emission spectra and the decay curves of phosphors demonstrated the existence of multiple Eu2+ emitting centers. Eu2+ ions occupy at four Ba sites of Ba3-xSc(BO3)(3): xEu(2+) (0.03 <= x <= 0.15) emit orange light (lambda em = 670 nm and 560 nm) through 370 nm UV excitation. The broader absorption band, ranging from 220 nm to 550 nm, matches well with the near-ultraviolet LED chips. Furthermore, color tuning from orange to red is successfully achieve by the double doping of Gd3+-Ba2+ and Mg2+-Sc3+ in Ba2.97Sc(BO3)(3): 0.03Eu(2+). Our results indicate that red emission Ba3Sc(BO3)(3): Eu2+ phosphors is an ideal candidate for the application in white light-emitting diodes. (C) 2019 Elsevier B.V. All rights reserved.