Orientation and strain modulated electronic structures in puckered arsenene nanoribbons

TL;DR

This study shows that nanostructuring and applying strain to arsenene nanoribbons can convert their bandgap from indirect to direct and significantly modulate their electronic and transport properties, advancing 2D material engineering.

Contribution

It reveals how nanostructuring and strain can control the electronic properties of arsenene nanoribbons, a novel approach for 2D material applications.

Findings

Nanostructuring arsenene into nanoribbons induces a direct bandgap.

Strain can further modulate the bandgap and transport properties.

Tensile strain enhances the bandgap energy in armchair nanoribbons.

Abstract

Orthorhombic arsenene was recently predicted as an indirect bandgap semiconductor. Here, we demonstrate that nanostructuring arsenene into nanoribbons can successfully transform the bandgap to be direct. It is found that direct bandgaps hold for narrow armchair but wide zigzag nanoribbons, which is dominated by the competition between the in-plane and out-of-plane bondings. Moreover, straining the nanoribbons also induces a direct bandgap and simultaneously modulates effectively the transport property. The gap energy is largely enhanced by applying tensile strains to the armchair structures. In the zigzag ones, a tensile strain makes the effective mass of holes much higher while a compressive strain cause it much lower than that of electrons. Our results are crutial to understand and engineer the electronic properties of two dimensional materials beyond the planar ones like graphene.