M01: Physical Properties of 2D Materials

Wed. March 6, 9:12 a.m. – 9:24 a.m. CST

L100A

Memristor devices are an emerging technology for low-power and highly-integrated memory and neuromorphic computing devices. Recent observations of non-volatile resistive switching (NVRS) in two-dimensional transition metal dichalcogenides promises near atomically-compact scaling compared to previous generations of bulk memristors. Although vertical two-terminal MoS2-based devices have been demonstrated experimentally, the mechanism(s) behind NVRS are not well understood. We examine one such mechanism based on the formation, diffusion, and dissolution of point defects. We use calculations based on density functional theory and the Boltzmann transport equation to evaluate potential switching mechanisms involving a heterostructure of monolayer MoS2 and (111)-Au substrate through an understanding of the defect electronic structure and ionic and electronic transport of defect complexes with sulfur vacancies. We will present on our results on how various effects from the substrate such as strain due to lattice mismatch, charge transfer, and dielectric screening impact defect formation energetics and diffusion. This study will discuss the mechanism(s) by which an external electric field would drive ionic diffusion, shifts of the chemical potential, and results in the corresponding change of the electronic conductivity.