Defect healing of CVD graphene by selective electroplating for mechanically robust and transparent electrodes

Abstract

Due to outstanding electrical and optical properties with flexibility, graphene has become a promising material for mechanically robust and transparent electronics. In addition, the development of chemical vapor deposition (CVD) method has enabled the production of high quality, large area graphene. Nevertheless, few industrial applications use graphene. This is because it is difficult to achieve the theoretical performance of graphene. The difference between theory and reality comes from intrinsic defects during the synthesis and integration of graphene. Mechanically robust and transparent electrodes applied to advanced electronic devices must satisfy high transmittance and robustness as well as conductivity.

In this study, it was first optimized that the selective electroplating for a robust and transparent electrode. Optimum conditions for a robust and transparent electrode were determined in consideration of electroplating time, concentration, and potential difference. Then, the selective electroplating was improved using surface treatment and mechanical bending. The first method, surface treatment enhanced the wettability of graphene. The improved wettability affected electroplating quality. Also, a mechanical strain was applied. Applying a strain to the graphene changes the electrical band structure

It was found that the properties of healed graphene electrode with surface treatment and mechanical bending were improved while maintaining a high level of transmittance. In addition, multilayer structure was applied to overcome the low conductivity compared to indium tin oxide (ITO), a widely used transparent electrode. The multilayered graphene electrode fabricated with optimized electroplating had enhanced mechanical robustness while maintaining the transmittance and conductivity of indium tin oxide. The proposed graphene electrode can be effectively used in various fields requiring both electrical and mechanical properties.