Energetics and gap engineering in alternating layer and intralayer substituted boron-nitrogen-carbon compounds

Abstract

Using ab initio quantum chemical methods, the electronic structures of both alternating layer (BNC 2) and intralayer substituted hybrids (BNC 2, BNC 3.33, BNC 6 and BNC 14) of graphite and hexagonal boron nitride are investigated. While total energy considerations under inclusion of interlayer interactions are emphasized for the former, the magnitude of the fundamental gap is of central interest for the latter. Our main results are: (1) alternating layer hybrids are not less stable than intralayer substituted species; (2) all compounds are found to be semiconductors; (3) the semiconducting behaviour is a consequence of the structural stabilization of charge density waves within the carbon sublattices; (4) at least in the case of intralayer substituted BNC compounds, gaps can theoretically be ‘engineered’ by varying the ratio of BN to C and by using the ‘concept of charge frustration’.