Color-tunable luminescence and energy transfer of Eu2+/Mn2+ co-doped Sr9Lu(PO4)(7) phosphors for white LEDs

摘要

A series of Eu2+ and Mn2+ activated novel Sr9Lu(PO4)(7) phosphors has been prepared through a high temperature solid state reaction. The obtained samples show a strong excitation band between 250 and 450 nm, which is in good agreement with near-ultraviolet (NUV) LED chips. Upon excitation at 365 nm, the Sr9Lu(PO4)(7):Eu2+ phosphor exhibits a broad yellowish-green emission band which peaks at 530 nm. In the Eu2+ and Mn2+ ions co-doped phosphors Sr9Lu(PO4)(7):Eu2+, Mn2+, tunable colors from yellowish-green to yellow can be obtained by varying the content of the Mn2+ ion. Additionally, energy transfer from the Eu2+ to Mn2+ ions is proven to follow a dipole-quadrupole mechanism according to the decay curves. These results indicate that the Sr9Lu(PO4)(7):Eu2+, Mn2+ phosphors could applicable for NUV based white light-emitting diodes. (C) 2017 Elsevier Ltd. All rights reserved.