Abstract
Epitaxial germanene on a semiconducting GaAs(0001) substrate is studied by ab initio calculations. The germanene-substrate interaction is found to be strong for direct contact but can be substantially reduced by H intercalation at the interface. Our results indicate that it is energetically possible to take the germanene off the GaAs(0001) substrate. While mounted on the substrate, the electronic structure shows a distinct Dirac cone shift above the Fermi energy with a splitting of 175meV. On the other hand, we find for a free standing sheet a band gap of 24meV, which is due to the intrinsic spin orbit coupling. (C) 2013 AIP Publishing LLC.