Eur. Phys. J. B 38, 19-24 (2004)
https://doi.org/10.1140/epjb/e2004-00094-0

Intensity and wavelength dependence of the photoconductivity in Cr-doped Sr_0.61Ba_0.39Nb₂O₆

¹ Institute for Mineralogy, University of Cologne, Zülpicherstr. 49b, 50674 Cologne, Germany
² Department of Physics, University of Osnabrück, Barbarastr. 7, 49069 Osnabrück, Germany

Corresponding author: ^a granzow@linux23.kri.uni-koeln.de

Received: 28 July 2003
Revised: 18 December 2003
Published online: 20 April 2004

Abstract

We examine the light-induced charge transport properties of a series of chromium-doped single crystals by measurements of the optical absorption and the electric conductivity. By comparing the wavelength dependence of the specific photoconductivity and the optical absorption we show that both effects stem from the same center. The intensity dependence of the photoconductivity shows the applicability of a one-center charge transport model for high doping concentrations, while for low doping concentrations a more sophisticated model is needed. The validity of a one-center model is exemplarily verified for a crystal doped with 0.51 mol % Cr over a wide intensity range using a holographic method. The product of mobility and recombination time of photoexcited electrons is deduced from the specific photoconductivity.