Crystallinity of silicon-shells deposited onto germanium and silicon nanowires for core-shell nanostructures and nanotubes

Core-shell nanowires are fundamental to several nanoscale device concepts. In this work, silicon and germanium nanowires were grown using the vapor-liquid-solid-method and modified with a thin silicon shell. The shell growth was thoroughly studied with respect to the crystallinity and the electrical properties. Furthermore, effects of certain post-annealing procedures are discussed. We show that by deliberate adjustment of the growth parameters the crystallinity of the silicon shell can be tuned from single-crystalline to amorphous in a controlled manner independent on a p- or n-type doping.