Blue-green BaAl 2O 4:Eu 2+,Dy 3+ phosphors synthesized via combustion synthesis method assisted by microwave irradiation

Abstract

Blue-green luminescent BaAl 2O 4:Eu 2+,Dy 3+ phosphor powders were synthesized via combustion synthesis method assisted by microwave irradiation in air. The phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and fluorescence spectrophotometer. The XRD results revealed that when the concentration of urea was over 3 times higher than theoretical quantities, a BaAl 2O 4 single hexagonal phase was obtained. The SEM results revealed that the surface of the BaAl 2O 4:Eu 2+,Dy 3+ powder samples showed lots of voids and pores. The BaAl 2O 4:Eu 2+,Dy 3+ phosphors exhibited a broad emission band of main peak at 496 nm and a shoulder peak at 426 nm under excitation of 337 nm. The BaAl 2O 4:Eu 2+,Dy 3+ phosphors at the Eu 2+ concentration of 1 mol.% showed the strongest luminescent intensity. Long afterglow phosphorescence was observed in the dark with naked eyes after the removal of the excitation source.