Out-of-plane structural flexibility of phosphorene

TL;DR

This study explores the out-of-plane flexibility of phosphorene, revealing its potential for flexible electronic applications due to its anisotropic buckling behavior and preserved electronic properties under certain deformations.

Contribution

It provides new insights into phosphorene's buckling behavior and electronic stability, highlighting its suitability for flexible device fabrication.

Findings

Phosphorene exhibits high out-of-plane flexibility along the armchair direction.

Buckling along the zigzag direction disrupts structural integrity at large curvatures.

The band gap remains direct under armchair buckling but becomes indirect with zigzag buckling.

Abstract

Phosphorene has been rediscovered recently, establishing itself as one of the most promising two dimensional group-V elemental monolayers with direct band gap, high carrier mobility, and anisotropic electronic properties. In this letter, the buckling and its effect on the electronic properties in phosphorene are investigated by using molecular dynamics simulations and complemented by density functional theory calculations. We find that phosphorene shows superior out-of-plane structural flexibility along the armchair direction, which allows the formation of buckling with large curvatures, while the buckling along the zigzag direction will break its structure integrity at large curvatures. The semiconducting and direct band gap nature are retained with buckling along the armchair direction; the band gap decreases and transforms to an indirect band gap with buckling along the zigzag direction. The structural flexibility and electronic robustness along the armchair direction facilitate the fabrication of devices with complex shapes, such as folded phosphorene and phosphorene nano-scrolls, thereby offering new possibilities for the application of phosphorene in flexible electronics and optoelectronics.