Pentaoctite phase: A new group V allotrope

Abstract

By performing firt-principles electronic calculations we propose new a phase of group-V allotropes of antimonene, arsenene and phosphorene in the pentaoctite structure. By calculating the phonon spectra, we show that all these phases are stable. Whereas these structures have a indirect band gap, they can be made direct gap materials by applying external strain. GW calculations of the dielectric function demonstrate that all these structures have an absorption spectrum in the visible region, which could be useful for group-V optoelectronics.