Screen printing of silver nanowires: balancing conductivity with transparency while maintaining flexibility and stretchability

Abstract

Printing metal nanowires are particularly attractive as compared to conventional coating methods due to the ease of processing, direct patterning, and large-scale fabrication capability. However, it is still challenging to print metal nanowire patterns that simultaneously have high conductivity, high transparency, flexibility, and stretchability. Three steps have been taken in this work to balance the transparency and conductivity of the screen-printed flexible and stretchable silver nanowire films, (1) selection of the ink formulation, (2) optimization of the printing parameters, and (3) posttreatment with a laser. The as-obtained silver nanowire patterns are large-area and demonstrate an ultralow sheet resistance of 1.9 ohm/sq, high transmittance (73%) at the wavelength of 550 nm, and an ultrahigh figure of merit (~136) as compared to the printed silver nanowire electrodes in the literature. The screen-printed transparent patterns exhibit excellent electrical stability and mechanical repeatability when subjected to 1000 bending cycles with a bending radius of 28 mm and 1000 stretch-release cycles with 10% strain, which makes the transparent patterns suitable for the fabrication of flexible, transparent microwave absorbers. The absorption performance of the prepared frequency selective surface absorbers indicates no obvious degradation after various manipulating configurations and multiple bending and stretching cycles. The results are promising enough to make this ink and screen-printing process suitable for many applications of flexible, stretchable, and transparent electronics.