Mechanisms of doping graphene

Abstract

Abstract We distinguish three mechanisms of doping graphene. Density functional theory is used to show that electronegative molecules like tetrafluoro‐tetracyanoquinodimethane (F4‐TCNQ) and electropositive metals like K dope graphene p‐ and n‐ type, respectively. These dopants are expected to lead to a decrease in carrier mobility arising from Coulomb scattering but without any hysteresis effects. Secondly, a novel doping mechanism is exhibited by Au which dopes bilayer graphene but not single layer. Thirdly, electrochemical doping is effected by redox reactions and can result in p‐doping by humid atmospheres and n‐doping by NH 3 and toluene.