Photoluminescent Spectra of Nd 3+ Codoped CaAl 2 O 4 :Eu 2+ Blue Phosphor

Abstract

Phosphor material CaA l2O4 : Eu2+ codoped with varying concentrations of Nd3+ was prepared by solid-state reaction method. Prepared materials with 1 mol% Eu2+ and Nd3+ (0.5 to 5 mol%) show high brightness and long persistent luminescence. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Photoluminescence excitation and emission spectra were taken to investigate the luminescence characteristics. Broadband UV excited luminescence of the CaA l2O4 : Eu2+ , Nd3+ was observed in the blue region ( λmax = 440 nm) due to transitions from 4f 6 5d1 to the 4f 7 configuration of the Eu2+ ion. The Nd3+ ion doping in the phosphor generates deep traps which result in long afterglow phosphorescence.