Superflexibility of ITO Electrodes via Submicron Patterning

ACS Appl Mater Interfaces. 2018 Mar 28;10(12):10339-10346. doi: 10.1021/acsami.7b19098. Epub 2018 Mar 14.

Abstract

Indium tin oxide (ITO) is the premier choice for transparent conductive electrodes in optoelectronic devices despite its inherent brittleness. Here we report the fabrication of a grating-like structure that obviates ITO's mechanical limitations while retaining its resistivity and optical qualities. ITO nanopatterned films exhibited a resistivity <1.3 × 10-3 Ω cm, which surpassed all previously reported values for flexible ITO, with a normal transmission >90% across the whole visible spectrum range. We demonstrate the nanopatterned ITO retains extraordinary flexibility and durability on heat-sensitive substrates, accommodating cyclic bending to a curvature diameter of at least 3.2 mm for over 50 cycles of compressive and decompressive flexing without significant deterioration of its resistivity or optical properties. Moreover, 2-dimensional extrapolation shows that multiaxial bending is also feasible while maintaining mechanical flexibility, durability, and optical transparency.

Keywords: flexibility; indium tin oxide; periodic grating pattern; transmittance; transparent electrodes.