Study of Electronic Structure of Boron-Nitride /Graphene Bilayer by Using DFT

Abstract

In this work, we study the electronic structure (number of open channels (NOC), band structur(BS), density of states (DOS), and I-V curve) of boron nitride/ graphene sheet using SIESTA and GOLLUM codes. Ab initio structural optimization performs for all structures using the local density approximation (LDA) with norm-conserving pseudopotentials, double zeta polarized (DZP) basis sets of pseudoatomic orbitals, and the Ceperley-Alder exchange correlation functional with the atomic forces relaxed to 0.02 eV/ËšA. Three types of simulated heterostructures sheets have been studied: 1- One graphene strip and one boron nitride strip sheet. 2- Two graphene strip and one boron nitride strip sheet. 3- Three graphene strip and one boron nitride strip sheet. We show that there is a dramatic reduction in energy gap ‘E_g’ of heterostructures comparing with the insulator boron nitride (E_g4.6 eV) and increasing in energy gap comparing with semimetallic graphene (zero gap).