Sol-gel synthesis and the luminescent properties of CaNb2O6 phosphor powders

Synthesis and luminescence properties of CaNb2O6 oxides by the sol-gel process were investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), photoluminescence spectroscopy and absorption spectra. The PL spectra excited at 257 nm have a broad and strong blue emission band maximum at 457 nm, corresponding to the self-activated luminescence of the niobate octahedra group [NbO6](7-). The optical absorption spectra of the 700 degrees C sample exhibited the band-gap energies of 3.53 eV. (C) 2008 Elsevier B.V. All rights reserved.