Covalent and van der Waals interactions in a vertical heterostructure composed of boron and carbon

Abstract

In this paper a covalent assembly of two two-dimensional (2D) materials is investigated. It is shown that borophene with periodic perforation (as one of numerous 2D boron nanoallotropes) and graphenylene can form the vertical heterostructure. This borophene-graphenylene bilayer reduces the dynamic instability inherent in certain types of 2D boron. A detailed study of the nature of the interatomic bonds shows that covalent forces and van der Waals forces act alternately between a pair of neighboring boron and carbon atoms. The electronic and mechanical properties of the predicted heterostructure are comprehensively investigated: in the equilibrium condition, under strain, and with passivation by atomic hydrogen. Several calculation schemes are used to increase the accuracy of the electronic structure calculations. It is shown that the tension and the passivation of borophene-graphenylene from the carbon layer by hydrogen can strongly affect the band gap. The mechanical properties of this heterostructure correspond to the properties of one of its materials, graphenylene. The use of this material to stabilize 2D boron nanoallotropes, as well as in flexural nanoelectronics, is promising. © 2022 American Physical Society.