Selective Surface Treatment Using Atmospheric Ar Plasma Jet for Aluminum-doped Zinc Oxide Based Transparent and Flexible Electronics

Transparent and flexible electronics are emerging technologies with the potential to enable new applications. However, to ensure high-performance transparent electronics, post-processing such as thermal annealing and vacuum plasma treatment is necessary, which are difficult to apply to polymer-based flexible substrates. This study analyzed the feasibility of applying selective Ar plasma jet treatment at atmospheric pressure to transparent flexible electronics. When atmospheric Ar plasma treatment is applied to transparent flexible aluminum-doped zinc oxide (AZO), it showed a maximum 83.1% improvement in sheet resistance while maintaining a high transmittance performance, of over 70%. To verify the mechanism behind the surface treatment effect using atmospheric Ar plasma, comprehensive analyses are performed using atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, which confirmed that the effect is due to oxygen vacancy formation caused by ion bombardment and thermal diffusion. The application of atmospheric plasma treatment to a patterned transparent flexible AZO device resulted in a reduction in contact resistance, and it is confirmed that the performance improvement effects can be retained for >500 h by applying additional passivation.