Silicene and Germanene: A First Principle Study of Electronic Structure and Effect of Hydrogenation-Passivation

Journal of Computational and Theoretical Nanoscience (Impact Factor: 1.03). 03/2014; 11(3):1-8. DOI: 10.1166/jctn.2014.3428

ABSTRACT Using first principle calculations we have explored the structural and electronic properties of silicene (silicon analogue of graphene) and germanene (germanium analogue of graphene). The structural optimization reveals that buckled silicene and germanene are more stable than their planar counterparts by about 0.1 and 0.35 eV respectively. In comparison to planar graphene (buckling parameter Δ = 0 Å) the germanium sheet is buckled by 0.737 Å and silicene by 0.537 Å but both have similar electronic structure with zero band gap at K point as that of graphene. Further we investigated the effects of complete hydrogenation on these materials by considering different geometrical configurations (chair, boat, table and stirrup) and found that chair-like structure has the highest binding energy per atom in comparison to other structures. Hydrogenated silicene (silicane) shows an indirect band gap of 2.23 eV while hydrogenated germanene (germanane) possess a direct band gap of 1.8 eV.



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May 31, 2014