The photoluminescent (PL) and electroluminescent (EL) characteristics in the thin films of various Bi-activated niobate-based oxide phosphors have been investigated. LaNbO(4):Bi, GdNbO(4):Bi and YNbO(4):Bi phosphor thin films were prepared on thick BaTiO(3) ceramic sheet substrates by either a conventional or a combinatorial radio frequency magnetron sputtering deposition followed by postannealing at a high temperature. Blue PL emissions were observed from Bi-activated niobate-based oxide phosphor thin films postannealed at a temperature above approximately 800 degrees C in air or a pure At gas atmosphere. The excitation spectra of the blue PL emissions as well as the blue emission spectra observed from LaNbO(4):Bi, GdNbO(4):Bi and YNbO(4):Bi phosphor thin films exhibited an increasing red-shift in that order. In addition, blue, whitish blue-green or blue-green emissions were observed from thin-film electroluminescent devices fabricated with a LaNbO(4):Bi, a GdNbO(4):Bi or a YNbO(4):Bi thin-film emitting layer, respectively. However, the EL emission spectra observed from these TFEL devices exhibited a red-shift relative to the PL emission spectra observed from the respective phosphor thin films. The resulting difference between the observed PL and EL emission spectra may be explained by the 6 s(2)-6 s6p transitions in Bi(3+) ions. In particular, the long-wavelength bands observed in the EL emissions may be attributable to the selection rule resolved by a high electric field applied to the phosphor thin films. (C) 2009 Elsevier B.V. All rights reserved.