Continuous Fabrication of Highly Conductive and Transparent Ag Mesh Electrodes for Flexible Electronics

Abstract

Flexible transparent conductive electrodes are essential components for flexible electronics and more functions are combined in such components for miniaturization and design flexibility. The embedded metal mesh, due to the merits of good transparency, conductivity, and flexibility, is regarded as a promising candidate for transparent conductive electrodes. This study reports a continuous fabrication approach of roll-to-roll ultraviolet-nanoimprint lithography (R2R UV-NIL) for the large-area fabrication of embedded Ag mesh electrodes on polyethylene terephthalate (PET) substrates. It has the potential to replace the vacuum-based metal deposition process in flexible transparent electrodes fabrication for large-area, high-throughput, and low-cost production. A R2R UV-NIL system is developed that consists of microchannels patterning stage, doctor blading stage, and Ag residual layer removing stage. A nickel mold for the R2R UV-NIL process is theoretically designed and practically developed. A prototype of embedded metal mesh has been fabricated using water-based, nanosilver paste, and the electrical and optical performance have been further improved by wet etching. The optical transmittance and the sheet resistance are 82.0% and 22.1 Ω/sq, respectively. The electrical and optical performance is excellent with a high ${\sigma _{{\rm{dc}}}}/{\sigma _{{\rm{opt}}}}$ value of 81. It is demonstrated that the R2R UV-NIL process is feasible for the large-area fabrication of embedded Ag mesh for flexible transparent electrodes.