Investigation on charge transfer bands of Ce4+ in Sr2CeO4 blue phosphor

Bulk and nano-materials Sr2CeO4 were prepared by solid-state reaction and sol-gel technique, respectively. The Stokes shift, the full width at half maximum (FWHM) as well as the decay time suggest that luminescence originates from a ligand-to-metal Ce4+ charge transfer (CT) emission. Compared with the bulk Sr2CeO4, the nano-material exhibits stronger emission intensity, longer decay time, and higher CT excitation energy. Three CT excitation peaks were observed in both bulk and nano samples. CT mechanism was discussed.