Stability and electronic structure of tricycle-type allotropes of pnictogen monolayers

Abstract

We report stability and electronic structure of tricycle-type allotrope of pnictogen monolayers within state-of-the-art density functional theory (DFT) calculations. The considered monolayer structure of two-dimensional (2D) As and Sb are found to be energetically more stable than the previously reported puckered and buckled structures, however, 2D Bi prefer zigzag-type high-buckled structure. Electronic band structure calculations suggest the considered monolayers structure to be narrow direct bandgap semiconductors with bandgap ranging 0.2-0.6 eV along with Dirac-cone features at band edges. Spin-orbit coupling (SOC) further reduce the bandgap by shifting the band edges towards Fermi level. We believe that our theoretical study will add more 2D materials with Dirac-cone features in the fascinating class of family and may guide the experimentalists to realize them for various nanoelectronic applications. © 2019 Author(s).