The influence of random edge defects on the electric and optical properties of phosphorene nanoribbons along zigzag direction

Phosphorene nanoribbons are one-dimensional semiconductors with possible edge states falling within its energy bandgap. We build the connection between the possible configurations of edge defects and the corresponding electric and optical properties in practice systems. The influence of the random defects or roughness at the edges of phosphorene nanoribbons cutting along zigzag direction is investigated quantitatively. Theoretical calculations show that the absorption peak due to the transitions involving edge states has an obvious blue shift with the zigzag-type positions at the edges increasing. The absorption thus can be used to estimate the random defects or roughness of the edges of phosphorene nanoribbons.