First Principles Calculations of Graphene Doped with Al, P and Si Heteroatoms


C.R García

Abstract. In this work, studies of the doping effects on the electronic and structural properties of
graphene were performed. Calculations have been done within the periodic density functional
theory (DFT) as implemented in PWscf code of the Quantum Espresso Package. Graphene layers
have been modeled using the 4×4 periodic supercells. The doping is explored considering
phosphorus (P), aluminum (Al) and silicon (Si) heteroatoms. One heteroatom per supercell was
considered. Electronic structure results show that the pristine graphene has a linear dispersion at
high symmetry K point and zero gap. Band structure of graphene doped with Al atoms exhibit a
metal behavior since a valence band crosses the Fermi level. Graphene doped with P also presents a
metal behavior but in this case a conduction band crosses the Fermi level. In addition, when the
dopant is Si the band structure shows a semiconductor behavior with a 0.3 eV gap. In all cases, the
zero gap energy characteristic of graphene was changed by dopant heteroatom. The Dirac lineal
dispersion relation is preserved only in the pristine graphene.

Artículo-CERG 2 2017