Uncovering the Anisotropic Electronic Structure of 2D Group VA-VA Monolayers for Quantum Transport

Two-dimensional (2D) materials with anisotropic electronic structures possess promising prospect for ultra-scaled field effect transistors (FETs), such as black phosphorene. Here, the quantum transport properties of anisotropic 2D group VA-VA monolayers with puckered configuration are studied in 5 nm FETs using density functional theory and nonequilibrium Green's function. Through evaluating and comparing the transport effective mass (m(x)) and density of state (m(DOS)) of these 2D group VA-VA monolayers, we uncover the physical mechanism of the anisotropic electronic structures for the performances of 2D ultra-short FETs. These electronic structures can make the channel with a small m(x) hold a high mDOS, or the channel with heavy m(x) hold a small mDOS, which is beneficial to obtain high saturation current, steep sub-threshold swing, and thus a high on-current. Hence, the strong anisotropic electronic structure can be regarded as a target feature for designing high performance 2D FETs, which provides a guideline for exploring excellent 2D channels for ultra-scaled electronic devices.