Photoluminescent Spectra of Nd3+ Codoped CaAl2O4:Eu2+ Blue Phosphor

Abstract

Phosphor material CaA l 2 O 4 : Eu 2 + codoped with varying concentrations of Nd 3 + was prepared by solid-state reaction method. Prepared materials with 1 mol% Eu 2 + and Nd 3 + (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 l 2 O 4 : Eu 2 + , Nd 3 + was observed in the blue region ( λ max = 440 nm) due to transitions from 4 f 6 5 d 1 to the 4 f 7 configuration of the Eu 2 + ion. The Nd 3 + ion doping in the phosphor generates deep traps which result in long afterglow phosphorescence.