A HydroDynamic Model for Trap-Assisted Tunneling Conduction in Ovonic Devices

Abstract

Electrical conduction in ovonic threshold switching (OTS) devices is described by introducing a new physical model where the multiphonon trap-assisted tunneling (TAT) is coupled to a hydrodynamic theory. Static and transient electrical responses from GexSe <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${}_{{1}-{x}}$ </tex-math></inline-formula> experimental devices are reproduced, outlining the role played by the material properties like mobility gap and defects in tuning the OTS performances. A clear physical interpretation of the mechanisms ruling the different OTS conduction regimes (off, threshold, on) is presented. A nanoscopic picture of the processes featuring the carrier transport is also given. The impact of geometry, temperature, and material modifications on device performance is discussed providing physical insight into the optimization of OTS devices.