An efficient co-doping of Eu and Er in CaAl2O4 aluminate phosphor

CaAl2O4:Eu2+ co-doped with varying concentrations of Er3+ was prepared by solid-state reaction method. Prepared materials with 1 mol% Eu2+ and 2–10 mol% of Er3+ 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 CaAl2O4:Eu2+, Er3+ in the blue region (λmax=440 nm) due to transitions from 4f65d1 to the 4f7 configuration of the Eu2+ ion. The Er3+ ion co-doping generates deep traps, which results in longer decay time for phosphorescence.