Super-Flexibility of ITO Electrodes via Submicron Patterning.

Indium tin oxide (ITO) films are the premier choice of transparent conductive electrodes in optoelectronic devices, yet their application is limited in flexible substrates due to its inherent brittleness. Here we report on the fabrication of a simple ITO grating-like structure that allows it to overcome its mechanical limitations while retaining resistivity and optical qualities. The ITO nanopatterned film exhibited a resistivity < 1.3 × 10-3 Ω cm, which surpassed all previously reported values for bendable ITO and a normal transmission > 90% in the whole visible spectrum range. We demonstrate it indeed delivers extraordinary flexibility and durability on heat-sensitive substrates, bending to a curvature diameter of at least 3.2 mm for over 50 cycles of compressive and decompressive flexing test, without significant resistivity or optical properties deterioration. Moreover, by creating a suitable 2-dimensional extrapolation, the multiaxial bending was realized while maintaining the mechanical flexibility, durability and optical transparency.