Synthesis and photoluminescence of highly enhanced green-emitting LaNbTiO6:xEr3+, yBi3+ micro/nanophosphors

In this paper, we provided a new green-emitting LaNbTiO6:xEr(3+), yBi(3+) micro/nanophosphors with good photoluminescence (PL) performance synthesized by a modified sol-gel combustion method for the first time. Down-converted luminescence from Er3+, Bi3+ co-doped into the LaNbTiO6 host was observed under UV light excitation, in which the strongest emission peaks centered at 525 and 548 nm are attributed to the H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions of Er3+, respectively. The greatly enhanced luminescence of LaNbTiO6:xEr(3+), yBi(3+) phosphors can be derived from the effective Bi3+ -> Er3+ energy transfer process, of which the mechanism is mainly related to the exchange interaction. CIE chromaticity coordinates for LaNbTiO6:xEr(3+), yBi(3+) phosphors could be tunable in green spectral region by controlling the concentration of Bi3+ ions. It is also affirmed from the high brightness fluorescence images that LaNbTiO6:xEr(3+), yBi(3+) phosphors could be the promising candidates for use in white LEDs application. (C) 2012 Elsevier Ltd. All rights reserved.