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 (lambda(max) = 440nm) due to transitions from 4f(6)5d(1) to the 4f(7) configuration of the Eu2+ ion. Ti3+ ion co-doping generates deep traps, which results in longer afterglow phosphorescence. (c) 2007 Elsevier B.V. All rights reserved.