Selective charge doping of chemical vapor deposition-grown graphene by interface modification

The doping and scattering effect of substrate on the electronic properties of chemical vapor deposition (CVD)-grown graphene are revealed. Wet etching the underlying SiO2 of graphene and depositing self-assembled monolayers (SAMs) of organosilane between graphene and SiO2 are used to modify various substrates for CVD graphene transistors. Comparing with the bare SiO2 substrate, the carrier mobility of CVD graphene on modified substrate is enhanced by almost 5-fold; consistently the residual carrier concentration is reduced down to 10(11) cm(-2). Moreover, scalable and reliable p-and n-type graphene and graphene p-n junction are achieved on various silane SAMs with different functional groups. (C) 2013 AIP Publishing LLC.