Junction Welding Techniques for Metal Nanowire Network Electrodes

Transparent conductive electrodes (TCEs), which offer advantages of high electrical conductivity and optical transparency, are essential components of practical high-tech optoelectronics such as touch panels, e-papers, organic light-emitting diodes, and solar cells. Solution-processed Ag nanowires (AgNWs) have been considered as a practical alternative TCE material suitable for industrial-scale mass production. However, the contact resistance at AgNW junctions strongly affects the total sheet resistance of AgNW electrodes. In recent years, various welding techniques for AgNW network electrodes have been developed with the aim of decreasing their sheet resistance while maintaining their optical transmittance. In this paper, we present a review of various welding methods such as thermal-mechanical welding, light welding, chemical welding, and metal-plating welding.