1 research outputs found
Alloyed surfaces: New substrates for graphene growth
We report a systematic ab-initio density functional theory investigation
of Ni(111) surface alloyed with elements of group IV (Si, Ge and Sn),
demonstrating the possibility to use it to grow high quality graphene.
Ni(111) surface represents an ideal substrate for graphene, due to its
catalytic properties and perfect matching with the graphene lattice
constant. However, Dirac bands of graphene growth on Ni(111) are
completely destroyed due to the strong hybridization between carbon p(z)
and Ni d orbitals. Group IV atoms, namely Si, Ge and Sn, once deposited
on Ni(111) surface, form an ordered alloyed surface with root 3 x root
3-R30 degrees reconstruction. We demonstrate that, at variance with the
pure Ni(111) surface, alloyed surfaces effectively decouple graphene
from the substrate, resulting untrained due to the nearly perfect
lattice matching and preserves linear Dirac bands without the strong
hybridization with Ni d states. The proposed surfaces can be prepared
before graphene growth without resorting on post-growth processes which
necessarily alter the electronic and structural properties of graphene.
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