Enhanced luminescence through ion-doping-induced higher energy phonons in GdTaO4:Eu3+ phosphor

Abstract

The photoluminescence enhancement effect of Li-, Zn-, or Al-doped GdTaO4:Eu3+ is investigated at 20 and 295 K. The underlying reason of luminescence enhancement by ion doping is revealed, and a mechanism of the enhancement based on the temperature effect is proposed. It can be safely concluded that the photoluminescence enhancement effect originates from temperature enhancement effect, which can be further strengthened by ion-doping-induced higher energy phonons, which are demonstrated by infrared transmittance spectra. This can reasonably explain why the photoluminescence is remarkably enhanced by ion-doping in GdTaO4:Eu3+ phosphor at 295 K rather than at 20 K.