Core–shell Si1−xGex nanowires with controlled structural defects for phonon scattering enhancement

Abstract

We demonstrate for the first time core–shell Si_1−xGe_x alloy nanowires that can suppress the phonon propagation in nanowires without reducing the electrical conductivity. Non-uniformly distributed structural defects in the outer shells of the Si_1−xGe_x nanowires enhance boundary scattering during phonon transport, while a defect-free core provides a current path for electrical carriers.