Cross-alignment of silver nanowires network for efficient nanowelding

The performance of silver nanowire (AgNW) network flexible transparent electrodes is limited by large contact resistance, making it necessary to perform nanowelding to improve conductivity of the network. However, not all nanowire junctions can be welded. Our work indicates that the welding kinetics between nanowires depend on the crossing angle, with higher surface diffusion velocity prone to welding and fracture at nanowire junctions of crossing angles close to 90 degrees. The impact of nanowire crossing angles on the welding process makes it difficult to achieve simultaneous welding of random AgNWs networks. To address this issue, we adopted an improved Meyer rod coating method to prepared a cross-aligned nanowire network based on a layer-by-layer assembly strategy. Compared to randomly distributed AgNWs networks (11.17 Ω sq^-1, 85.2%), the cross-aligned AgNWs network achieved simultaneous welding of nanowire junctions during thermal annealing, further enhancing the optoelectronic performance (10.8 Ω sq^-1, 90.3%) of the AgNWs network, resulting in a superior figure of merit value of 421.