Maskless deposition of patterned transparent conductive oxides via laser-assisted atmospheric pressure plasma jet

Transparent conductive oxides (TCOs) are indispensable as transparent electrodes in optoelectronic ap-plications due to their unique features of high optical transmittance, high electrical conductivity, and cost-effective industrial-scale manufacturability. However, patterning TCO films for functional devices requires lengthy and expensive photolithography and etching processes. Although the laser patterning techni-que-based on nanoparticle ink and particle-free ink-has been used to fabricate patterned metal electrodes without photolithography, it is still unknown if it works for TCO, such as doped zinc oxide (ZnO). Here, we introduce a novel single-step maskless, particle-free, and ink-free process to deposit transparent, con-ductive Ga-doped ZnO (GZO) patterns on glass substrates via a laser-assisted atmospheric pressure plasma jet (APPJ) technique. With the exposure of a plasma jet, GZO patterns can be deposited by scanning a continuous-wave CO2 laser using a galvanometer and computer-aided design (CAD) images. The GZO patterns (similar to 100 nm thick) are visually transparent and exhibit remarkably low resistivity of 7.89 x 10-4 omega cm, comparable with that of uniform (unpatterned) GZO films prepared by APPJ only. Our present work fun-damentally differs from prior works since neither particles nor ink is applied to the substrate before pro-cessing. The entire process is conducted in ambient conditions without substrate preheating and pre-/post -processing. Also, it does not require expensive vacuum apparatus and pulsed laser sources and has a high potential for cost-effective and sustainable fabrication of TCO patterns and circuits. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Transparent conductive oxides (TCOs) are essential for optoelectronic applications. This study presents a novel method for patterning transparent conductive zinc oxide (ZnO) films on glass substrates using a laser-assisted atmospheric pressure plasma jet (APPJ) technique.