Luminescence thermal enhancement of Eu 3+ using charge transfer band excitation in Li 6 Zn 3 (BO 3 ) 4 :Eu 3+ phosphors

Li 6 Zn 3 (BO 3 ) 4 (LZB):Eu 3+ phosphors were synthesized by solid phase sintering reaction. The lattice structure and variable luminescence properties were investigated by powder X-ray diffraction and fluorescence spectra. LZB:Eu 3+ phosphors showed luminescence thermal enhancement (LTE) under 255 nm excitation, and thermal quenching under 394 nm excitation. LTE was proved to be caused by the redshift and the increase in absorption of charge transfer band (CTB) with increasing temperature. This experiment shows that LTE of down conversion can be achieved by using the change of CTB with rising temperature.