First principles study of stability and electronic properties of Sn/Ge core-shell nanowire

In the present work, we have presented core/shell geometry of GeSn NW, where Ge shell is built around very thin Sn cores. We have studied phonon dispersive curve and its binding energy for dynamical and thermodynamic stability of the NW. We have observed direct bad gap of 0.68 eV for the Sn/Ge NW. The valance band is contributed by Ge atom, while the conduction band is contributed by Sn atom near the Fermi level. The direct band gap in Sn/Ge NW indicates its potential application in Si-based light emitting diode as future light energy source.