Ab initio quantum transport simulations of defective devices based on 2-D materials via a projected-GW approach

We propose a novel ab inito defect modeling framework for devices based on two-dimensional (2-D) transition-metal dichalcogenide (TMDC) monolayers. The so-called projected (p)- GW method is combined with density functional theory and incorporated into the non-equilibrium Green’s function equations to efficiently and accurately investigate the influence of various defect types on the characteristics of 2-D field-effect transistors. Through quasi-particle correlated defect-level modeling, we show that one single defect located inside the channel under the gate is a main source to block the current flow, thus leading to a large performance degradation. Our variability study also confirms that defects inside transistors based on 2-D TMDC monolayers induce a significant threshold voltage shift and ON-state current variation.