Investigation of electronic property modulation driven by strain in monolayer tellurium

Abstract

Density functional theory (DFT) calculations have been employed to systematically investigate the strain-modulated electronic properties of monolayer tellurium. The results demonstrate that at zero strain γ-phase monolayer tellurium is found to be more energetically favorable than either the α-phase or β-phase which were fabricated through molecular-beam epitaxy. All studied phases are found to exhibit semiconductor characteristics, of which α- and γ-phases possess indirect band gaps whereas β phase is a direct band gap semiconductor. It is also found that the resulting band gap values approach zero at a large strain regime for all systems and the effective mass of electron and hole can be effectively modified by biaxial strain as well. These findings extend the knowledge on two-dimensional tellurium and provide potential applications in electronic devices.