Structural and electronic properties of clean and defected Si-SiC(001) surfaces

摘要

We have studied the reconstructions and electronic properties of both clean and defected Si-terminated (001) surfaces of cubic SiC, by performing -first principles computations within density functional theory. We find that the unstrained bulk exhibits a stable p(2xl) reconstruction, whereas a bulk under tensile stress shows a c(4x2) 1econstruction Furthermore our calculations indicate that ad-dimers are common defects on the Si-terminated SIC(001) surface These results permit the interpretation of recent STM and X-ray- photoemission experimental data.