Monte Carlo simulation of charge transport in amorphous chalcogenides

The most peculiar feature exhibited by $I(V)$ characteristics of amorphous chalcogenides materials is undoubtly its S-shape given by a negative differential-resistance behavior. In order to pursue a theoretical control of such a behavior so important for technological exploitation, in this paper we give a microscopic particle description of the charge transport across a simple device of amorphous $mathrm{Ge_2Sb_2Te_5}$ sandwiched between two planar metallic contacts. Specifically, a transport scheme based on the generalization of the variable range hopping has been implemented in a current-driven Monte Carlo simulation that allows one to investigate the aspects of the microscopic picture responsible for the electrical properties of the device. Results obtained are compared with experimental data.% and the other models available in the literature.

The most peculiar feature exhibited by the I (V) characteristics of amorphous-chalcogenide materials is undoubtedly its S-shaped behavior. This type of characteristics is very important for the technological application, e.g., in the field of nanoscale solid-state memories. In this paper we give a microscopic particle description of the charge transport across a layer of amorphous Ge2 Sb2 Te5 sandwiched between two planar metallic contacts. A transport scheme based on the generalization of the variable-range hopping has been implemented in a current-driven Monte Carlo code. This approach allows one to investigate the aspects of the microscopic picture responsible for the electrical properties of the device. The results are compared with experimental data. © 2009 American Institute of Physics.