Room temperature high-efficiency welding of an ultra-long silver nanowire network for flexible transparent electrodes

In the preparation of flexible electronic devices, obtaining a transparent conductive electrode with high electrical conductivity, high transparency, and mechanical flexibility is a significant challenge. This study developed a simple method for preparing ultra-long silver nanowires (ul-AgNWs), obtaining high-purity ul-AgNWs with an average length of 317.66 ± 98.60 μm, an average diameter of 78.06 ± 13.87 nm, and an aspect ratio exceeding 4000. Integrating these ul-AgNWs with a polyethylene terephthalate (PET) film, a flexible transparent electrode (FTE) with R_s = 561 Ω and T = 97% was obtained. The ul-AgNWs were welded by driving the welding liquid to the intersection points through surface tension, resulting in a decrease of R_s to 61 Ω, T = 98.2%, and achieving a FTE with excellent mechanical properties. Furthermore, this FTE was applied in the preparation of OLED devices, showing a turn-on voltage of 2.7 V, and the maximum current efficiency and power efficiency reached 58.6 mA cm⁻² and 64.7 lm W⁻¹, respectively, demonstrating its significant potential in flexible optoelectronic devices.