First-Principles Study of One-Dimensional Antimony Selenide Nanoribbon

Abstract

The discovery of graphene and other 2D materials has led to extensive research on the effect of reduced dimensionality on the physical properties of van der Waals layered materials. In this thesis study, we explored the anisotropic nature of one-dimensional antimony selenide (Sb2Se3) nanoribbon. We investigated its electronic properties as well as strain-mediated modulation of their electronic properties. We performed a systematic study of atomic and electronic structure of Sb2Se3 bulk and nanoribbon using first-principles density functional theory. Elastic strain was found to have large impact on both atomic and electronic structure, which led to bandgap widening under small strain. Elastic strain also generated ripple formation and an indirect-to-direct band gap transition at large strain. The results demonstrated that it is possible to modify the band gap of ribbon-like chalcogenide materials via strain engineering, shedding light on potential straintronic applications. Furthermore, surface termination of bulk Sb2Se3 was studied and van der Waals surfaces were found to be the most stable ones. The results indicated the absence of dangling bonds at the surfaces of Sb2Se3 grains which is potentially beneficial to the photovoltaic performance.