Preparation, luminescence properties and energy transfer of Ca9Y(PO4)7: Eu2+‐Tb3+ phosphors. Issue 7 (3rd April 2017) - Tang, Miao
Abstract: Tb 3+ ‐doped and Eu 2+, Tb 3+ co‐doped Ca9 Y(PO4 )7 phosphors were synthesized by conventional solid‐state method. Additionally, the luminescence properties, decay behavior and energy transfer mechanism have already been investigated in detail. The green emission intensity of Tb 3+ ions under NUV excitation is weak due to its spin‐forbidden f‐f transition. While Eu 2+ can efficiently absorb NUV light and yield broad blue emission, most of which can be absorbed by Tb 3+ ions. Thus, the emission color can be easily tuned from cyan to green through the energy transfer of Eu 2+ →Tb 3+ in Ca9 Y(PO4 )7 :Eu 2+, Tb 3+ phosphor. In this work, the phenomenon of cross‐relaxation between 5 D3 and 5 D4 are also mentioned. The energy transfer is confirmed to be resulted from a quadrupole‐quadrupole mechanism.