First principles study of the structural and electronic properties of the in-plane SiC/GeC heterostructures

The atomic structures and electronic properties of the in-plane heterostructures composed of the polar SiC and GeC sheets (SiC/GeC) have been systematically studied within the framework of density functional theory. The mismatch of 5.4% between SiC and GeC sheet induces a strain in the combined heterostructures leading to a compression in the GeC domain and an expansion in the SiC domain, respectively. It was found that such strain strongly influences the electronic properties on the densities of states, the band gap, and the transition from in-direct to direct band gap. The partial charge distribution density, charge transfer, and the charge density difference analyses also revealed the effect of interface depending on either the armchair or the zigzag heterostructures. These results provide significant information to clarify the correlation between atomic structures and electronic properties of the in-plane SiC/GeC heterostructures and a fundamental picture for further theoretical studies and device design based on such ionic-like heterostructures.