Electronic properties of mixed-phase graphene/h-BN sheets using real-space pseudopotentials

Abstract

A major challenge for applications of graphene is the creation of a tunable electronic band gap. Hexagonal boron nitride has a lattice very similar to that of graphene and a much larger band gap, but B-N and C do not alloy: B-C-N materials tend to phase separate into h-BN and C domains. Quantum confinement within the finite-sized C domains of a mixed B-C-N system can create a band gap, albeit within an inhomogeneous system. Here we investigate the properties of hybrid h-BN/C sheets with real-space pseudopotential density functional theory. We find that the electronic properties are determined not just by geometrical confinement, but also by the bonding character at the h-BN/C interface. B-C terminated carbon regions tend to have larger gaps than N-C terminated regions, suggesting that boron-carbon bonds are more stable. We examine two series of symmetric structures that represent different kinds of confinement: a graphene dot within a h-BN background and a h-BN antidot within a graphene background. The gaps in both cases vary inversely with the size of the graphenic region, as expected, and can be fit by simple empirical expressions.

Exploring the Linear Optical Properties of Borazine (B3N3) Doped Graphenes. 0D Flakes vs 2D Sheets

“…As in the case of finite models, all methods suggest that h BNG hybrid systems should bear nonzero band gaps lying always lower than the computed band gap of pure h BN. Our all-electron ab initio and DFT results agree with the so far reported theoretical plane-wave outcomes dealing with the band gap sizes of h BNG hybrids and their dependence on the concentration in BN. − This tendency is also confirmed by experimental measurements on h BNG hybrids which reported band gaps smaller than 1 eV …”

Electronic properties of T graphene-like C–BN sheets: A density functional theory study

“…It is found that graphene-like BN sheet is a large indirect band gap semiconductor [17,18]. In addition, hybrid C and BN (C-BN) sheets exhibit very interesting electronic properties [19,20]. For instance, it is shown that graphene-like BC 2 N sheet is a semiconductor with a direct band gap [21,22].…”

Postsynthesis of h‐BN/Graphene Heterostructures Inside a STEM

“…Understanding edge structures at the h‐BN/graphene domain boundaries at atomic levels is extremely important, as B‐C terminated carbon regions tend to have larger band gaps than N–C terminated regions . Previously, we reported in‐plane graphene growth at the step‐edge of bilayer graphene.…”