First-principles study of electronic properties of multilayer palgraphyne and BN palgraphyne-like sheets

Abstract

Palgraphyne is a new two-dimensional carbon allotrope with orthorhombic symmetry. The study of structural and electronic properties of bi- and tri-layer C and BN palgraphyne is the main purpose of the present work. The effect of the number of layers on the electronic properties is investigated by density functional theory calculations. The thermal stability of multilayer palgraphyne is evident from the calculation of the formation energy and ab-initio molecular dynamics simulations. The layers are attached via weak van der Waals interactions. Electronically, bi- and tri-layer C palgraphyne are semimetals as well as monolayer. The number of Dirac points increases with increasing the number of layers. The considered BN palgraphyne sheets show insulating properties. The band gap of BN palgraphyne is influenced by the number of layers. The multilayers have an energy gap smaller than monolayer BN palgraphyne. These results promise practical applications of C and BN palgraphyne in nanoelectronic devices.