Strain and interface effects on the stability and electronic properties of SiGe/GeC lateral heterostructure

A systematic investigation of the strain and interface effects on the stability and the electronic properties of SiGe/GeC lateral heterostructure is being carried out from the first principle calculations. Our preliminary results have shown that there exists a strong local strain due to the large lattice mismatch (over 20 %) between buckled SiGe and flatted GeC domains, and such local strain is distributed anisotropically. It is strong along the interface and weak inside the domains perpendicular to the interface. The stabilized structure of such heterostructure with the armchair interface shows a combination of a quasi-flatted GeC domain with a low buckled SiGe domain either in the Si-Ge/Ge-C type of bonding or in the Si-C/Ge-Ge type of bonding at the interface. However, a high buckling in the SiGe domain is found in such heterostructure with the zigzag interface. More interestingly, a gap opening is found in the system with the armchair interface, as compared to the gapless of the SiGe sheet, indicating its promising application in band gap engineering. Detail discussion will be presented in the presentation.