Presentation Information
[20a-A306-8]Geometric structure of graphene thin films under an external electric field
〇(D)Nadia Sultana1, Yanlin Gao1, Mina Maruyama1, Susumu Okada1 (1.Univ. Tsukuba)
Keywords:
graphene,electric field,geometric structure
The electronic structure of graphene thin films is sensitive to the stacking arrangement and the external electric fields [1]. In particular, a perpendicular electric field make a bilayer graphene with Bernal stacking a semiconductor whose band gap is proportional to the field strength [2,3]. Therefore, the field-effect on electronic properties of graphene thin films has attracted considerable attention in electronics and optoelectronic fields. Despite the electronic structure is modulated by the external electric field, the geometric properties of graphene thin films are uncertain under the external electric field. Therefore, in this work, we aim to elucidate the geometric properties of multilayer graphene under the perpendicular electric field using the density functional theory combined with the effective screening medium method. The equilibrium spacing is slightly extended by the external electric field for bilayer graphene with AA and AB stacking arrangement. Field-induced asymmetric charge polarization on each graphene layer increases the interlayer spacing. We will be discussing the structural modifications induced by both external electric field and excess carrier doping.