Highly enhanced mechanical stability of indium tin oxide film with a thin Al buffer layer deposited on plastic substrate

摘要

We here report that the mechanical stability of indium tin oxide ([TO) film deposited on the plastic substrate can be highly enhanced by a thin metal buffer layer with a minimized loss of transparency. Neither cracks nor fragmentation was observed for a 75 nm-thick ITO film with a 5 nm-Al layer even after severe bending to a radius of curvature of 1.25 mm, while a 160 nm-ITO film of similar surface resistance was cracked at 9 mm. The improved crack resistance is accounted for by the fact that the effective elastic mismatch between the film and the substrate can be alleviated with a ductile buffer layer, thus the crack propagation is suppressed.