Photoluminescent studies on Ti co-doped CaAl2O4:Eu2+, Ti3+ phosphor

Titanium ion co-doped CaAl2O4:Eu2+, Ti3+ phosphor was investigated. New compositions with combinations of Eu2+ (1 and 2 mol%) and Ti3+ (0.2–0.3 mol%) were prepared by solid-state synthesis method. These compositions show high brightness and longer persistent luminescence compared to parent phosphor. Phase and crystallinity were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Excitation and emission spectra were taken to investigate the luminescence characteristics. Broadband UV-excited luminescence of the CaAl2O4:Eu2+, Ti3+ was observed in the blue region (λmax=440 nm) due to transitions from 4f65d1 to the 4f7 configuration of the Eu2+ ion. Ti3+ ion co-doping generates deep traps, which results in longer afterglow phosphorescence.