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Semiconducting graphene
Kolev K. S., Atanasov A. V., Aleksandrov A. H., Popov N. V., Milenov I. T.,
Published in
2019
Volume: 51

Issue: 4
Pages: 552 - 556
Abstract
In this paper we propose a simple way for structural modification of graphene yielding a non-zero band gap which is mandatory for prospective electronics applications. This can be achieved by creating a buffer layer graphene (BuLG) upon deposition on different crystalline silicon surfaces. Previous calculations have shown that the formation of such buffer layer on 4H-SiC results in lattice deformation of BuLG, due to the 8% mismatch between the (0001)Si crystal surface of SiC and the graphene lattices. Here, for elimination of the lattice deformation, we propose a replacement of the (0001)Si surface of SiC by hydrogen atoms. Using density functional simulations we show that the band gap of the corrugated graphene sheet is $\Delta$E = 1.94 eV (hydrogenated system) or $\Delta$E = 1.21 eV SiC/graphene system. Height of corrugation is equal to h = 35.0 ± 5.0 pm. Two effects are responsible for the band gap opening: corrugation of the sheet, caused by the covalently bonded carbon atoms and removal of electrons from the bonding $\pi$ orbitals of graphene.