A method of fabricating a micro-networked metal electrode using a self-cracking WO3 oxide thin film as a sacrificial layer is presented. The width of the formed crack can be adjusted to a size of 10 to 40 µm by adjusting the wet-etching time in dilute NaOH solution, and accordingly, the electrical conductivity and transmittance of the electrode can be adjusted. An electrical conductivity of approximately 100 Ω/sq was measured at an average transmittance of 95.6% in the visible light region, and when applied to a flexible substrate, the electrical resistance was maintained stable even with repeated bending tests. The method proposed in this study can be applied to various transparent flexible electrode devices.
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT & Future Planning (NRF-2019R1A2C1006972).