Electronic Properties of Edge-Hydrogenated Phosphorene Nanoribbons: A First-Principles Study

Abstract

We perform first-principles calculations to study the electronic structures and edge properties of phosphorene nanoribbons (PNRs) with and without edge hydrogenation. In contrast to the direct band gap semiconducting characteristic observed in phosphorene sheet, bare armchair PNRs are semiconductors with an indirect band gap, while bare zigzag PNRs are conductors. Through edge hydrogenation, both armchair and zigzag PNRs become semiconductors with a direct band gap. Interestingly, the electronic properties of edge-hydrogenated PNRs are independent of their edge orientation, which are in contrast to that of bare PNRs that show a significant edge orientation-dependence. In addition, our edge energy and stress analysis show that hydrogenated PNRs have an extremely low edge energy and also low edge stress, indicating that they are stable both energetically and mechanically. The present work indicates that hydrogenated PNRs, which are of a moderate band gap energy, a direct band gap, and high edge stability, a...