High mobility, printable, and solution-processed graphene electronics

Abstract

The ability to print graphene sheets onto large scale, flexible substrates holds promise for large scale, transparent electronics on flexible substrates. Solution processable graphene sheets derived from graphite can form stable dispersions in solutions and are amenable to bulk scale processing and ink jet printing. However, the electrical conductivity and carrier mobilities of this material are usually reported to be orders of magnitude poorer than that of the mechanically cleaved counterpart due to its higher density of defects, which restricts its use in electronics. Here, we show that by optimizing several key factors in processing, we are able to fabricate high mobility graphene films derived from large sized graphene oxide sheets, which paves the way for all-carbon post-CMOS electronics. All-carbon source-drain channel electronics fabricated from such films exhibit significantly improved transport characteristics, with carrier mobilities of 365 cm2/(V · s) for hole and 281 cm2/(V · s) for electron, measured in air at room temperature. In particular, intrinsic mobility as high as 5000 cm 2/(V · s) can be obtained from such solution-processed graphene films when ionic screening is applied to nullify the Coulombic scattering by charged impurities. © 2010 American Chemical Society.