High-performance flexible transparent conductive films achieved by cooperation between 1D copper nanowires and 2D graphene materials

Abstract

Flexible transparent conductive films (TCFs) fabricated from indium tin oxide (ITO)-alternative materials are highly desirable for a variety of present and future (opto-)electronics. In this contribution, we report that the hybridization of a kind of two-dimensionally electro-conductive material and a kind of one-dimensionally electro-conductive material, i.e. reduced graphene oxide (rGO) and copper nanowires (CuNWs), is a good choice to meet such desire. Different combination ratios between these two kinds of materials by either adding CuNWs into rGO bulk or vice versa were tested. It was found that a significant synergistic effect in improving TCF performance takes place between two-dimensional (2D) rGO nanosheets and one-dimensional (1D) copper nanowires. That is, 1D metallic CuNWs are superior to 2D rGO nanosheets as a conducting additive to improve the performance of TCFs mainly based on the rGO material, while 2D rGO nanosheets rather than 1D CuNWs are very good additives for CuNW-based TCFs to decrease sheet resistance with a small sacrifice in film transparency. Moreover, the hybridization of CuNWs with rGO can not only significantly reduce datum fluctuation in sheet resistance, but also improve the anti-oxidation and anti-foldability properties of TCFs mainly based on CuNWs. Finally, flexible TCFs with a transmittance at 550 nm larger than 80% and a sheet resistance down to 50 Ω sq⁻¹ have been achieved on a polyethylene terephthalate (PET) substrate.