Band transport and localised states in modelling the electric switching of chalcogenide materials

The role of the extended (band) states in determining the electric switching of chalcogenide materials in the amorphous phase is here analysed by means of a theoretical/simulative approach which accounts for both mobile and localised states. This goal is accomplished by including a parabolic dispersion relation for the mobile states into a set of equations of the hydrodynamic type. Simulation results have been obtained for three chalcogenides particularly appealing for technological applications. Comparison is reported with available experimental results for nanometre devices. Furthermore, a comparative analysis of the outcomes of the present model with data from other theoretical approaches based on different physical assumptions is carried out.