Defect-Induced Different Band Alignment and Transport of All-Phosphorene Devices from First Principles

Abstract

Defects are unavoidable in the preparation of materials and can significantly impact the properties of two-dimensional material-based devices. In this work, we proposed and investigated theoretically an all-phosphorene device, in which single vacancy (SV) and double vacancy (DV) defects were considered. It was found that the SV defect changed the original Schottky contact of the all-phosphorene device into a contact similar to that of a metal and a p-type doped semiconductor; the DV defect introduced some impurity states in the forbidden band. The impurity states expanded in a zigzag direction and localized in the armchair direction. The different electronic structures caused by the defects resulting in currents also exhibited defect-related anisotropic characteristics.