Bi3+-doped Sr3Al2O6: An unusual color-tunable phosphor for solid state lighting

A Sr3-xAl2O6:xBi(3+) phosphor crystallized in space group Pa (3) over bar was prepared by high-temperature solid-state reaction. Two emission bands (lambda(em) = 440 nm and 400 nm) and two excitation bands (lambda(ex) = 330 nm and 295 nm) were observed, which can be attributed to Bi3+ in distinct crystallographic sites. The optimal intensity of 400 nm emission band was observed for the phosphor doped with 1 at% Bi3+ (x=0.01), while that of 440 nm emission band was found in the phosphor with 2 at% Bi3+ (x=0.02). The emission color varies from the greenish blue to blue and even violet blue as the excitation wavelength increases from 275 to 335 nm. The Sr3-xAl2O6:xBi(3+) is a potential blue phosphor for ultraviolet light-emitting diodes. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.