Fabrication of ultrathin, free-standing, transparent and conductive graphene/multiwalled carbon nanotube film with superior optoelectronic properties

Here we report a wet chemical technique to obtain transparent electrodes for optoelectronic devices. This technique is simple, facile, low cost and an effective way to prepare ultrathin free standing hybrid graphene/multiwalled carbon nanotubes (MWCNT) films. The graphene/MWCNT films, up to 36 mm in diameter, with controllable thickness and root mean square surface roughness of the order of 12.6 nm are prepared. The ratio of graphene/MWCNT is optimized to make them free standing and easily transferrable on various substrates. The ratio of direct current conductivity to the optical conductivity (sdc/sopt) which is considered as figure of merit for transparent conductors, is enhanced to 10.27 for graphene/MWCNT hybrid films. The prepared films showed outstanding transmittance up to 87.3 +/- 1% at 550 nm, 87.9 +/- 1% at 800 nm and sheet resistance of 136 +/- 22.4 Omega/sq. (C) 2015 Elsevier B.V. All rights reserved.The authors acknowledge the funding support from Council of Scientific and Industrial Research-Senior Research Fellowship (CSIR-SRF), ICMR-SRF, RGNF-JRF, Nanotechnology: Impact on Safety, Health and Environment Program (CSIR-NANOSHE, BSC0112), and academic support from Central Scientific Instruments Organization (CSIR-CSIO), Academy of Scientific and Innovative Research (AcSIR-CSIR-CSIO Chandigarh). We acknowledge Dr. Ananth Venkatesan from IISER Mohali for his valuable guidance. We also acknowledge IISER Mohali and IIT Ropar for providing us SEM and AFM characterization facilities