Structural and electronic properties study of Si/Ge core/shell nanowire: A DFT study

Abstract

We have employed the density functional theory (DFT) to study structural, electronic and vibrational properties of H-passivated Si/Ge core-shell nanowire. The dynamical stability of the NW is analyzed by formation energy and phonon dispersion curve. We have observed that there is a decrease in band gap in the core/shell as compared to its corresponding pure nanowires, which may be due to the strain induced at Ge-shell in presence of Si-core. The Si/Ge nanowire shows direct band gap of 1.47 eV. The stable structure with direct band gap nanowire could show potential applications in the field of the sensors, bipolar and FET transistor.