Tunable Thermal Quenching Properties of Na3Sc2(PO4)3:Eu2+ Phosphors Tailored by Phase Transformation Details

The luminescence thermal quenching of phosphors is one of the prominent problems in restricting its application in high power LED devices. In the current work, tunable luminescence thermal quenching behaviors including abnormal negative thermal quenching and normal thermal quenching are demonstrated for Na3Sc2(PO4)3:Eu2+ phosphors tailored by the phase transformation details. A series of ionic substitution schemes are employed to synthesize α-, β- and γ-Na3Sc2(PO4)3:Eu2+ phosphors, which show discrepant phase transformation details during heating. The thermal event associated with phase transformation is revealed to be responsible for the observations of abnormal negative thermal quenching performances, in view of the suppression of non-radiative paths by consuming thermal energy during phenomenon of phase transformation. Our results provide an insight into the relationship between the thermal quenching behaviors and phase transformation details of Na3Sc2(PO4)3:Eu2+ phosphor and offer a useful clue in exploiting high thermal stability phosphors.