Applied Surface Science, Vol.387, 51-57, 2016
VOx effectively doping CVD-graphene for transparent conductive films
Chemical vapor deposition(CVD)-synthesized graphene is potentially an alternative for tin-doped indium oxide (ITO) transparent conductive films (TCFs), however its sheet resistance is still too high to meet many demands. Vanadium oxide has been widely applied as smart window materials, however, no study has been reported to use it as dopant to improve the conductivity of graphene TCFs. In this study, we firstly reported that VOX doping can effectively lower the sheet resistance of CVD-graphene films while keeping its good optical properties, whose transmittance is as high as 86-90%. The optimized VOX-doped graphene exhibits a sheet resistance as low as 176 Omega/square, which decreases by 56% compared to the undoped graphene films. The doping process is convenient, stable, economical and easy to operate. What is more, VOX can effectively increase the work function(WF) of the film, making it more appropriate for use in solar cells. The evolution of the VOX species annealed at different temperatures below 400 degrees C has been detailed studied for the first time, based on which the doping mechanism is proposed. The prepared VOX doped graphene is expected to be a promising candidate for transparent conductive film purposes. (C) 2016 Elsevier B.V. All rights reserved.