Investigation of Charge Transport in Amorphous Ge2Sb2Te5 Using the Variable-Range Hopping Model

Chalcogenide GST materials can suitably be exploited for manufacturing phase-change memory devices. In this paper a transport model for the amorphous phase of GST is investigated, based on the variable-range hopping model. The model is implemented into a Monte Carlo current-driven simulation of a test device made of a layer of amorphous Ge₂Sb₂Te₅ in contact with two planar metallic electrodes. The mechanisms governing electron transport within the device are discussed in relation to the variation of physical parameters, such as operating current, trap density, and coupling with the electric field inside the device.