Ultrafast laser-assisted selective removal of self-assembled Ag network electrodes for flexible and transparent film heaters

Ultrafast laser-based selective removal of self-assembled Ag network electrodes on PET substrates is demonstrated to be an effective patterning method at a high pulse repetition rate in the heat accumulation regime. The Ag network was completely removed, not only by direct laser ablation, but also by efficient delamination of the Ag network from the substrate, which is result of the local heat accumulation caused by MHz range pulse irradiation. Temporal energy distribution was carefully optimized by controlling either pulse repetition or the number of sub pulses in a burst packet to induce the proper heat accumulation at the interface between Ag and the PET substrate. The laser processing window that reflected the heat accumulation effect was found to be well below the ablation threshold of PET, thereby avoiding damage of the PET substrate during laser scanning. Successful operation of the flexible and transparent film heaters (FTFHs) with a laser-patterned Ag network electrode indicates that ultrafast laser patterning is a simple and promising technology for the fabrication of patterned Ag network-based FTFHs that enable high yield production to meet a variety of industrial requirements. (C) 2016 Elsevier B.V. All rights reserved.