Electro-conducting polymeric films prepared from the hybrids of carbon nanotubes and graphene nanosheets

Transparent and electro-conducting hybrid films were fabricated from unoxidized graphene nanosheets and single-walled carbon nanotubes (SWCNTs). A graphene dispersion was prepared in N-methylpyrrolidone (NMP) with ultrasonication. This ultrasonication method allows the preparation of unoxidized graphene nanosheets. Therefore, graphene nanosheets could be obtained with a low defect concentration and good electro-conductivity. In the hybrid films of graphene nanosheets and SWCNTs, the graphene nanosheets were interconnected by SWCNTs. A transparent hybrid film with relatively low sheet resistance could be prepared because this interconnected structure between the SWCNTs and graphene nanosheets can act as an electro-conducting pathway. As a result, the hybrid film showed improved electrical, transparent characteristics using unoxidized graphene, even though a small amount of SWCNTs were used. The hybrid films had 90% transmittance at 550 nm and a sheet resistance of 1.9 × 10³ /sq.