An efficient co-doping of Eu and Er in CaAl 2O 4 aluminate phosphor

Abstract

CaAl 2O 4:Eu 2+ co-doped with varying concentrations of Er 3+ was prepared by solid-state reaction method. Prepared materials with 1 mol% Eu 2+ and 2–10 mol% of Er 3+ were investigated for their photoluminescence properties. Phase, morphology and crystalline structure were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Broad band UV-excited luminescence was observed for CaAl 2O 4:Eu 2+, Er 3+ in the blue region ( λ max=440 nm) due to transitions from 4f 65d 1 to the 4f 7 configuration of the Eu 2+ ion. The Er 3+ ion co-doping generates deep traps, which results in longer decay time for phosphorescence.