EFFECT OF COMPOSITION AND STRUCTURE ON TRANSPORT PROPERTIES OF CHALCOGENIDE GLASSES

The effect of preparation regime and molecular composition on dispersive transport properties of amorphous chalcogenide films of As-Se, As2S3-Sb2S3 and As2S3 : Sn has been investigated by time-of-flight method. Hole transit time (corresponding to drift mobility) in the system As-Se was found to be dependent on preparation regime, this dependence being mostly exhibited in non-stoichiometric films. In As2S3-Sb2S3 system the transit time and its activation energy are gradually decreased with increasing of Sb2S3 content. The transit time of As2S3 films doped with Sn up to 0.3 at.% is decreased by as much as 3 to 4 orders of magnitude at room temperature and in the interval from 295 to 360 K increases with temperature. The results are discussed in frames of a model for anomalous charge carrier drift controlled by capture in a system of energy distributed traps