Mechanisms of doping graphene

TL;DR

This paper explores three distinct doping mechanisms in graphene, including molecular, metal, and electrochemical methods, highlighting their effects on electronic properties and layer-specific behaviors.

Contribution

It identifies and characterizes three novel doping mechanisms in graphene, including a layer-dependent gold doping process and electrochemical doping effects.

Findings

F4-TCNQ and K dope graphene p- and n-type respectively

Gold dopes bilayer but not single-layer graphene

Electrochemical doping occurs via redox reactions in humid atmospheres and with certain chemicals

Abstract

We distinguish three mechanisms of doping graphene. Density functional theory is used to show that electronegative molecule like 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 NH3 and toluene.