Thermal stability and surface passivation of Ge nanowires coated by epitaxial SiGe shells.

Epitaxial growth of a highly strained, coherent SiGe alloy shell around a Ge nanowire core is investigated as a method to achieve surface passivation and carrier confinement, important in realizing nanowire devices. The high photoluminescence intensity observed from the core shell nanowires with spectral features similar to that of bulk Ge indicates effective surface passivation. Thermal stability of these core shell heterostructures has been Systematically investigated, with a method demonstrated to avoid misfit strain relaxation during postgrowth annealing