Fabrication of metallic and transparent electrode layer by selective laser sintering or ablation of nanomaterial

Abstract

Metallic and transparent electrode layer, either patterned or non-patterned, are inevitable components for any electronic devices. These conducting layers are fabricated by standard photolithography and vacuum deposition methods in general, however, practical limitations such as high processing temperature and the use of toxic chemicals exist in conventional IC fabrication processes. As a result, the need for alternative electrode layer fabrication method is growing continuously especially in the area of low cost, large area flexible electronics.In this study, we present a simple approach for developing a flexible electronics fabrication without using conventional vacuum deposition and photolithography. We found that direct metal patterning based on laser-induced local melting of metal nanoparticle ink is a promising low-temperature alternative to vacuum depo-sition. and photolithography-based conventional metal patterning processes. The “digital” nature of the proposed direct metal patterning process removes the need for expensive photomask and allows easy design modification and short turnaround time. This new process can be extremely useful for current small-volume, large-variety manufacturing paradigms. Besides, simple, scalable, fast and low temperature process can lead to cost-effective fabrication methods on a large-area polymer substrate. The developed process was successfully applied to demonstrate high-quality Ag patterning (2.1 μΩcm) and high-performance metal grid transparent con-ductor (>85 % transmittance at <30 Ω/sq sheet resistance) for touch screen panel.Transparent conductors are being extensively studied recently due to the increasing demands in large-area optoelectronic devices such as light emitting diodes and thin film solar cells. Among potential alternatives, metal nanowire transparent conductor, or metal nanowire percolation network, has been studied extensively and become a markedly mature technology, however, its patterning method ha...