Shell-Thickness Controlled Semiconductor–Metal Transition in Si–SiC Core–Shell Nanowires

We study Si–SiC core–shell nanowires by means of electronic structure first-principles calculations. We show that the strain induced by the growth of a lattice-mismatched SiC shell can drive a semiconductor–metal transition, which in the case of ultrathin Si cores is already observed for shells of more than one monolayer. Core–shell nanowires with thicker cores, however, remain semiconducting even when four SiC monolayers are grown, paving the way to versatile, biocompatible nanowire-based sensors