Weak interaction between germanene and GaAs(0001) by H intercalation: A route to exfoliation

The epitaxial growth of germanene on semiconducting GaAs(0001) substrate is studied using $ab$-$initio$ calculations. The interaction of the germanene is found to be minimum with the substrate. Our obtained results strongly indicate that it is possible to take off germanene from the substrate to make it free standing. We demonstrate a methods to achieve this aim. We also address the electronic structure of germanene on GaAs(0001) substrate and found to be the Dirac cone shift above the Fermi level with the spltting of 160 meV. Forthermore, we calculate the band structure of the free standing germanene with and without substrate and found band gap of 24 meV due to the intrinsic spin orbit coupling.