Effect of repetitive strain on the electrical durability of graphene-based, flexible, transparent, conductive films

We report the effect of repetitive strain on the electrical durability of graphene-based flexible, transparent and conductive films (GTCFs). The graphene is catalytically synthesized on a Ni thin film by using thermal chemical vapor deposition. The synthesized graphene is transferred to a SiO2-covered Si wafer and transparent polymeric substrate through wet etching of the growth substrates. We confirm that monolayer graphene is formed with areal coverage of −80%. The transmittance and the sheet resistance of the fabricated GTCFs are 75.5% at a 550-nm wavelength and 730 Ω/sq., respectively. We investigate the durability of the electrical properties of the GTCFs against repetitive strain loading. We confirm that the GTCFs are electrically stable under a cyclic strain of up to 20%. The sheet resistance of the GTCFs increases with increasing applied strain and number of loading cycles. The cracks that are formed by the cyclic strain are responsible for the decreased electrical performance.