Patterned Carbon Nanotube Films for Transparent and Stretchable Electrodes

Abstract

Transparent electrodes play an important role in many optoelectronic devices such as liquid-crystal displays (LCDs), organic light-emitting diodes (OLEDs), e-paper, touch panels, and solar cells. Although tin doped indium oxide (ITO) has been broadly used in transparent conducting films, the brittle property of ITO has limited its applications in flexible transparent electrodes. To address these issues, carbon nanotubes (CNTs) have been considered as the alternatives of sputtered ITO due to their excellent mechanical, optical, thermal, and electronic properties. Here, we present a solution-processed assembly of mesh-patterned CNT films as transparent electrodes with high transparency and low sheet resistance. As contrary to the randomly deposited CNT films, the mesh-patterned CNT film can improve uniformity and reproducibility. The patterned CNT networks take advantage of attaining the percolation threshold at low concentration. Therefore, the mesh-patterned CNT films can provide both high transparency and low sheet resistance. In addition, the mesh-patterns can support stretchability while maintaining low sheet resistance dynamic range, enabling stretchable transparent electrodes. In this study, we report a facile approach of mesh-patterned CNT films as transparent electrodes with soft polymeric template by fluidic and capillary force. The mesh-patterns of CNT networks demonstrated in this study suggest a new concept of low-cost, high-throughput processes for the transparent CNT films.