Excellent optoelectrical properties of graphene oxide thin films deposited on a flexible substrate by Langmuir-Blodgett assembly

Transparent conductive films (TCFs) composed of ultra-large graphene oxide (GO) sheets are produced on a flexible poly(ethylene terephthalate) (PET) substrate using the Langmuir-Blodgett (L-B) assembly. The GO films are reduced using hydriodic (HI) acid followed by chemical doping treatments. The TCFs deliver excellent optoelectrical properties with a remarkable sheet resistance 1100 Omega sq(-1) at a transmittance of 91%, which is considered among the best. The plasma-treated PET substrate plays an important role in determining the chemistry and surface morphology of GO films: a combination of strong covalent bonds and pi-pi interactions between the GO and PET is revealed. The L-B assembly technique is suitable for the fabrication of flexible TCFs of optoelectronic devices on a large scale.