A Route to High-Quality Crystalline Coaxial Core/Multishell Ge@Si(GeSi)n and Si@(GeSi)n Nanowire Heterostructures

The layer-by-layer formation and characterization of conformally smooth, uniform, and single-crystalline Ge(core)/Si-Ge-Si(multishell) and Si(core)/Ge-Si(multishell) nanowire heterostructures is reported. The modulation of their radial composition is well-defined and there is precise control over a wide range of shell thicknesses regardless of the initial nanowire core diameter.