Stacks of graphene with silicane or germanane: a first-principles study

摘要

We report the results of density-functional theory calculations on the stability and properties of hybrid layered systems composed of graphene and silicane or germanane monolayers. We find that the interlayer binding energy between the sheets is comparable to that of graphite, indicating that the creation of the corresponding stacks is feasible. Moreover, we show that the hybrid systems are stable against the formation of defects caused by the transfer of hydrogen atoms from one layer to another. Finally, we find that the graphene layer of the graphene-germanane stack retains its pristine electronic properties, at least close to the Fermi level. Therefore, stacks of graphene with silicane or germanane may be utilized in graphene-based devices by combining zero-gap graphene with wide band-gap two-dimensional semiconductors.