Electronic Properties of Fluorine Functionalized Germanene Nanoribbons

Silicene and germanene are promising materials for future electronic devices due to high mobility and velocity of the carriers. The progress of these materials for device implementation has been hindered by the lack of bandgap in them. In this work, we propose a method of bandgap generation in germanene nanoribbons of zigzag type. We have used fluorine atoms to functionalize the germanene nanoribbon. Our calculations are based on the density functional theory in combination with the non-equilibrium Green's function. The dependence of the bandgap and the effective mass of the carriers on the width (number of atoms) of the nanoribbon is presented in this work. Furthermore, we have also evaluated the stability of the fluorine functionalized zigzag germanene nanoribbons and it is observed that with the formation energy of -1.60 eV/□, fluorine functionalization improves the stability of the nanoribbon. The obtained results suggest the potential use of the fluorine functionalized germanene nanoribbons as a material for the implementation of high performance field effect transistors.