A novel white emission in Ba10F2(PO4)6:Dy3+ single-phase full-color phosphor

A novel single-composition white-emitting phosphor Ba10F2(PO4)(6:)Dy3+ was synthesized by a high-temperature solid-state reaction. X-ray powder diffraction and Fourier transform infrared spectroscopic analyses confirmed the phase formation of Ba10F2(PO4)(6:)Dy3+. The luminescence properties show that the phosphor can be effectively excited by UV light (348 nm) and exhibits bright white-light emission centered at 479 and 574 nm, attributed to the F-4(9/2) -> H-6(15/2) -> and F-4(9/2) -> H-6(13/2) transitions of Dy3+ ions, respectively. The luminescence intensity of Ba10-xF2(PO4)(6:)xDy(3+) phosphor first increased and then decreased with increasing Dy3+ concentration, reaching the maximum at x = 0.35. The UV -visible diffuse reflectance spectra indicate that the optical band gap energy (E-g) values of Ba10F2(PO4)(6) and Ba9.65F2(PO4)(6):0.35Dy(3+) are 2.71 and 3.04 eV, respectively. The decay time was also determined for various concentrations of Dy3+ in Ba10F2(PO4)(6). The decay time analysis indicates that the Dy3+ ions occupied two lattice sites in Ba10F2(PO4)(6) host and the interactions or energy transfer/migration exists between the Dy3+ ions. The chromaticity coordinates were calculated and analyzed; the Commission International de I'Eclairage color coordinates fall in the white-light region. The results indicate that the white Ba10F2(PO4)(6):Dy3+ phosphor can serve as a key material for phosphor-converted light-emitting diode. (C) 2014 Elsevier B.V. All rights reserved.