2BeGeO 4:Mn 2+ phosphor]]>

摘要

Recently, developing free rare-earth (RE) doped afterglow phosphors has received great attentions in the lighting field. In this work, we prepare and report a RE-free phosphor, Na2BeGeO4:Mn2+, which can simultaneously emit the green fluorescence and afterglow luminescence upon excitation at UV light. Our results reveal that the as-prepared samples crystallize in orthorhombic type with the space group ofPmn21(31). The green emission is a broad band centered at 525?nm, corresponds to the4T1(4G)-6A1(6S) transition of Mn2+ions. After exposing to a 254?nm UV lamp for 10?min, the green afterglow luminescence seen with naked eyes can last more than 5?h. Together with the structural analysis and thermoluminescence (TL) spectra, the afterglow luminescence mechanism is also discussed in this work.