Ultrasonic Vibration-assisted Pulsed Laser Ablation of Silver Nanowire Films in Liquid with Energy-wide Processing Window

Abstract

Pulsed laser ablation (PLA) of silver nanowire (AgNW) films has been a promising method for fabricating patterned transparent conductive layers on flexible and stretchable substrates due to its advantages, including pattern flexibility, atmospheric and room-temperature processing, and fast and low-cost processing. However, despite the benefits of the PLA, its generally unclear surface quality has prevented its application in industrial manufacturing fields, as it typically uses light sources with wavelengths exceeding several hundred nanometers, which can induce unintended damage due to their high power. We investigate the degradation of transparency caused by redeposited silver nanoparticles (AgNPs) on the ultraviolet (UV) laser-ablated regions of the AgNW films, where the tendency differs primarily with the laser irradiation energy, as the laser fluence mainly affects the surface finish in the bulk PLA process. Transparency degradations were dominantly observed at the intermediate laser irradiation energies. In contrast, the non-ablated NWs and fully ablated NWs, with no degradation, were observed at low and high laser energies, respectively. These results indicate that PLA of AgNWs using high laser fluence is preferred for complete ablation; however, substrate damage remains a concern. Here, we demonstrate ultrasonic (US) vibration-assisted PLA of the AgNW film in liquid, enabling a wide energy-processing window by minimizing the redeposited AgNPs at intermediate laser energies. US vibration-induced cavitation in the liquid layer is expected to enhance the dispersion of AgNPs in the liquid, resulting in improved transmittance of the ablated regions compared to the atmospheric environment. The wide energy-processing window in the PLA of AgNWs provides a reliable fabrication method for achieving damage-free patterns of AgNW films for flexible and stretchable optoelectronic devices in manufacturing fields.