Optical properties and energy transfer of Eu 2+ /Ce 3+ co‐activated Na 3 Ca 6 (PO 4 ) 5 phosphor

Ce 3+ /Eu 2+ co‐doped Na 3 Ca 6 (PO 4 ) 5 phosphors were prepared using a combustion‐assisted synthesis method. X‐Ray powder diffraction (XRD) analysis confirmed the formation of a Na 3 Ca 6 (PO 4 ) 5 crystal phase. Na 3 Ca 6 (PO 4 ) 5 :Eu 2+ phosphors have an efficient bluish‐green emission band that peaks at 489 nm, whereas Ce 3+ ‐doped Na 3 Ca 6 (PO 4 ) 5 showed a bright emission band at 391 nm. Analysis of the experimental results suggests that enhancement of the Eu 2+ emission intensity in co‐doped Na 3 Ca 6 (PO 4 ) 5 :Eu 2+ ,Ce 3+ phosphors is due to a resonance‐type energy transfer from Ce 3+ to Eu 2+ ions, which is predominantly governed by an exchange interaction mechanism. These results indicate that Ce 3+ /Eu 2+ co‐doped Na 3 Ca 6 (PO 4 ) 5 is potentially useful as a highly efficient, bluish‐green emitting, UV‐convertible phosphor for white‐light‐emitting diodes. Copyright © 2014 John Wiley & Sons, Ltd.