Key Words:Photoluminescence properties; Phosphate; Blue emission; Thermal stability; LED
Abstract:A series of blue-emitting Ba5 - xCl(PO4)(3):xEu(2+) (0.004 :5x 0.016) phosphors were synthesized by conventional high-temperature solid state reaction. The structure and photoluminescence (PL) properties of the phosphors were investigated. The as-prepared phosphors exhibit broad excitation band ranging from 250 to 420 nm, and strong asymmetric blue emission band peaking at 436 nm. The optimum concentration of Eu2+ in the Ba5 - xCl(PO4)(3):xEu(2+) phosphor is x = 0.01, and the concentration quenching mechanism is verified to be the combined actions of dipole-dipole interaction and radiation re-absorption mechanism. The thermal stability of Ba5 - xCl(PO4)(3):xEu(2+) was evaluated by temperature-dependent PL spectra. Compared with that of commercial Ba5 - xCl(PO4)(3):xEu(2+) (BAM) phosphor, the Ba5 - xCl(PO4)(3):xEu(2+) phosphors exhibit similarly excellent thermal quenching property. In addition, the CIE chromaticity coordinates of Ba5 - xCl(PO4)(3):xEu(2+) (0.004 <= x <= 0.016) were calculated to evaluate the color quality. All the results indicate that Ba5 - xCl(PO4)(3):xEu(2+) is a promising candidate phosphor for near-ultraviolet (n-IN) pumped LED. (C) 2016 Elsevier B.V. All rights reserved.
Volume:171
Translation or Not:no