Extraordinary mechanical flexibility in composite thin films composed of bimetallic AgPt nanoparticle-decorated multi-walled carbon nanotubes

Flexible, transparent, and conducting composite thin films, constructed from multi-walled carbon-nanotube-supported silver–platinum alloy nanoparticles (AgPt–MWCNT) on a flexible polyethylene terephthalate (PET) substrate through the combination of a two-step polyol process for synthesizing composites of carbon nanotubes (CNTs) and metallic nanoparticles (NPs) with an ultrasonic atomization-spin coating method for preparing thin films, have been fabricated. AgPt NPs with an average size of approximately 26 nm were uniformly attached to the sidewalls of MWCNTs to form an effective and strongly mechanical conductive network. These composites were then exposed to microwave plasma irradiation, which can lower the contact resistance between the metallic NPs and CNTs and reinforce the network bridges. The resulting AgPt–MWCNT–PET thin films exhibit improved optoelectronic and mechanical properties, and they possess a sheet resistance of 154 Ω/sq with a transmittance of 80% at 550 nm. These values are competitive with those of most other CNT-based films. Most importantly, the corresponding sheet conductivity does not decrease even after 500 bending cycles. Therefore, the as-produced AgPt–MWCNT–PET films may be direct alternatives to indium tin oxide and other transparent conducting oxide films.