New pentaoctite phase of group-V nanostructures

Abstract

By performing first-principles electronic structure calculations, a new 2D pentaoctite phase of group-V allotropes of antimonene, arsenene, and phosphorene is proposed. By calculating the phonon-spectra, it is shown that these new materials are stable. In addition, these calculations reveal anisotropic elastic properties. Whereas these nanostructures in the pentaoctite phase exhibit indirect bandgaps, they can be made direct gap materials by applying an external strain. GW calculations of the dielectric function demonstrate that all these structures have an absorption spectrum in the visible region, which can be useful for group-V optoelectronics.