Strong interactions and charge transfers between a charged benzene molecule and multilayer graphenes

The interactions between a benzene molecule and multilayer graphenes have been studied in this work using a density-functional tight-binding method. Analysis of structural characteristics, energetics, charge distribution etc., uncovers remarkable charge transfer resulted from a strong interaction between the ionic benzene and neutral multilayer graphene that is not attained for their neutral counterparts, with a clear interesting trend of charge accumulation at the surface region. Moreover, the adsorption energy increases gradually as the increase of the number of graphene layers and the electronic density of states of the multilayer graphene is simply equivalent to the multiple of that of a single layer. The band gap of the multilayer graphene varies with the number of layers, which is not affected by the adsorption of ionic benzene but is altered by the neutral benzene adsorption by 0.05 eV.