AVS 57th International Symposium & Exhibition
    Graphene Focus Topic Tuesday Sessions
       Session GR+TF-TuA

Paper GR+TF-TuA12
Effect of Point-like Defects on the Atomic Structure and Electronic Properties of Graphene Supported on Amorphous SiO2

Tuesday, October 19, 2010, 5:40 pm, Room Brazos

Session: Graphene and 2D Nanostructures
Presenter: K.E. Kweon, University of Texas at Austin
Authors: K.E. Kweon, University of Texas at Austin
G.S. Hwang, University of Texas at Austin
Correspondent: Click to Email
Graphene supported on the common gate dielectric, SiO<sub>2</sub>, has been considered as a highly promising candidate for future electronics. Therefore, it is important to understand the interfacial interaction between graphene and SiO<sub>2</sub>. Most of the existing theoretical studies have modeled the underlying SiO<sub>2</sub> surface using defective or H-terminated crystalline structures. However, the gate oxide is amorphous and possibly has a number of point-like defects, yet no detailed study has been undertaken on the defect effect. In this talk, based on first principles calculations we present how the SiO<sub>2</sub>-graphene binding and consequent graphene electronic structure are influenced by the presence of point-like defects in not only SiO<sub>2</sub> surface but also graphene sheet. We considered six different surface defects on SiO<sub>2</sub>; silyl radicals [(≡Si-O-)<sub>3</sub>Si•], oxy radicals [(≡Si-O-)<sub>3</sub>Si-O•], silylene center [(≡Si-O-)<sub>2</sub>Si:], silanone [(≡Si-O-)<sub>2</sub>Si=O], peroxide radicals [(≡Si-O-)<sub>3</sub>Si-O-O•], and dioxasilirane [(≡Si-O-)<sub>2</sub>Si &lt;O<sub>2</sub> ], along with defective graphene that contains vacancies. This talk will mainly touch on the pathways and energetics of the defect-mediated graphene binding to SiO<sub>2</sub>, and how the covalent graphene-SiO<sub>2</sub> binding affects the electronic properties of graphene.