Luminescence centers in bismuth-containing oxytungstate ceramics

We have studied the photoexcitation and luminescence spectra of Bi₂WO₆, Y₂WO₆ and Y₂WO₆:Bi ceramics. We used the Alentsev-Fock method to decompose the spectra into elementary components. The emission bands with maximum at 2.93 eV in the luminescence spectrum of Bi₂WO₆, 3.02 eV in the luminescence spectrum of Y₂WO₆, and 2.95 eV in the luminescence spectrum of Y₂WO₆:Bi are assigned to luminescence of self-localized Frenkel excitons. The bands with maxima at 2.35 eV and 1.90 eV in the spectrum of Bi₂WO₆, 2.25 eV and 1.75 eV in the spectrum of Y₂WO₆, and 2.35 eV and 1.85 eV in the spectrum of Y₂WO₆:Bi are connected with oxygen vacancies. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 5, pp. 688–691, September–October, 2007.