Optical properties and energy transfer of Eu2+/Ce3+ co-activated Na3Ca6(PO4)5 phosphor

Ce3+/Eu2+ co-doped Na3Ca6(PO4)(5) phosphors were prepared using a combustion-assisted synthesis method. X-Ray powder diffraction (XRD) analysis confirmed the formation of a Na3Ca6(PO4)(5) crystal phase. Na3Ca6(PO4)(5):Eu2+ phosphors have an efficient bluish-green emission band that peaks at 489nm, whereas Ce3+-doped Na3Ca6(PO4)(5) showed a bright emission band at 391nm. Analysis of the experimental results suggests that enhancement of the Eu2+ emission intensity in co-doped Na3Ca6(PO4)(5):Eu2+,Ce3+ phosphors is due to a resonance-type energy transfer from Ce3+ to Eu2+ ions, which is predominantly governed by an exchange interaction mechanism. These results indicate that Ce3+/Eu2+ co-doped Na3Ca6(PO4)(5) is potentially useful as a highly efficient, bluish-green emitting, UV-convertible phosphor for white-light-emitting diodes. Copyright (c) 2014 John Wiley & Sons, Ltd.