Copper nanowires for flexible displays and solar cells
ITO contains approximately 70 % by weight of indium, an increasingly scarce metal whose supply is largely controlled by China. In addition to expense, ITO films lack flexibility and so cannot meet the demands of next-generation e-books and other devices exploiting flexible displays. A European consortium delivered a low-cost, flexible alternative to ITO with EU support of the project NANODIGREE (Low-cost, green, large scale manufacturing of new age conducting nanowires displays). The technology is based on advanced pulse electrodeposition of novel conductive and transparent inks containing Cu-based nanowires. Pulse electrodeposition is an eco-friendly, low-cost and well-controlled way to deposit the nanowires compared to conventional methods. The nanowires were deposited into the pores of a nanoporous template made of anodised aluminium oxide. Industrial-scale realisation was achieved by low-cost, high-throughput roll-to-roll inkjet printing onto flexible polyethylene terephthalate substrates. Finally, the substrate and the film were heated at a low temperature to form a transparent conductive layer with strong adhesion to the substrate. NANODIGREE's success will have major implications for the consortium's small and medium-sized enterprises. Although they have limited research capabilities, their intimate knowledge of the challenges faced is guiding the work of the research partners in a symbiotic way. Outcomes will enhance the competiveness of EU display manufacturers and support EU independence from Asian manufacturers.
Keywords
Copper nanowires, flexible displays, indium tin oxide, NANODIGREE, anodised aluminium oxide
