Self-Assembly of Water Soluble Graphene Nanosheets Into Transparent Conducting Film at the Hexane/Water Interface

Graphene based transparent conducting films have been fabricated by direct assembly of sulphonated graphene nanosheets at the hexane/water interface and sequentially transferred onto substrates. Scanning electron microscopy and atomic force microscopy observations confirm that these water soluble nanosheets could be effectively entrapped at the hexane/water interface and self-organized into monolayer with densely-packed topographical feature. After post-chemical doping treatments by nitric acid and thionyl chloride, the sheet resistance of the monolayer film decrease remarkably from 5280 Ω/sq to 965 Ω/sq with high optical transmittance over whole visible spectrum (86.5% at 550 nm). In addition, multilayered film with lower sheet resistance can be readily formed by layer-by-layer deposition of monolayer without any binding materials, demonstrating a cost-efficient, convenient and tuneable approach for high quality transparent conducting film.