Atomically thin group-V elemental films: theoretical investigations of antimonene allotropes

TL;DR

This study uses first principles calculations to investigate the stability, mechanical, and electronic properties of two stable allotropes of antimonene, revealing their potential for optoelectronic applications.

Contribution

It provides the first theoretical analysis of the stability and properties of α- and β-antimonene allotropes, including their electronic and mechanical characteristics.

Findings

Both allotropes are stable and semiconducting.

Distinct Raman spectra and STM images facilitate characterization.

Strain induces an indirect-direct band gap transition.

Abstract

Group-V elemental monolayers including phosphorene are emerging as promising 2D materials with semiconducting electronic properties. Here, we present the results of first principles calculations on stability, mechanical and electronic properties of 2D antimony (Sb), antimonene. Our calculations show that free-standing {\alpha} and \b{eta} allotropes of antimonene are stable and semiconducting. The {\alpha}-Sb has a puckered structure with two atomic sub-layers and \b{eta}-Sb has a buckled hexagonal lattice. The calculated Raman spectra and STM images have distinct features thus facilitating characterization of both allotropes. The \b{eta}-Sb has nearly isotropic mechanical properties while {\alpha}-Sb shows strongly anisotropic characteristics. An indirect-direct band gap transition is expected with moderate tensile strains applied to the monolayers, which opens up the possibility of their applications in optoelectronics.