  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.
