First principle study of fluorine functionalized germanene based two probe device

Highlights: • Bandgap Generation in zigzag Germanene Nano Ribbons (ZGeNR) by the method of chemical functionalization. • Study presents band structure and density of states analysis of both pristine and functionalized ZGeNR. • Stability analysis of the functionalized material is presented as ZGeNR in pristine form is not stable. • A Two probe device based on the functionalized ZGeNR is presented • Transmission spectrum and Eigen states of functionalized ZGeNR two probe device is presented and compared with its pristine counterpart. The high mobility and velocity of the carriers make germanene and silicene promising materials for future electronic devices like field-effect transistors. The lack of bandgap in these materials has been a prominent hurdle in the development of electronic devices based on them. This work presents a novel method of bandgap creation in zigzag germanene nanoribbons (ZGeNRs) by using fluorine (F) atoms as the functionalizing agent. A combination of density functional theory and non-equilibrium Green's function is employed for all the calculations. Variation of bandgap and effective mass of carriers with the width of the nanoribbons is also presented. Furthermore, a study of the transmission spectrum and transmission Eigen channels substantiates the semiconducting nature of F functionalized ZGeNRs. To assess the stability of F functionalized ZGeNRs, the formation energy of the nanoribbons is evaluated. The formation energy is found to be −1.60 eV/Å. Since the formation energy of F functionalized ZGeNRs is more negative than that of its pristine counterpart, the F functionalized ZGeNR is more stable than its pristine counterpart. Such results are suggestive of the potential of F functionalized ZGeNRs for future nano-scale devices.