Fabrication of a foldable transparent conductive electrode with suppressed silver migration by anchoring fluorinated alkyl passivated silver nanowires on a PET surface

Abstract

Tethering silver nanowires (AgNWs) on polymeric membranes is a highly applicable strategy for constructing flexible transparent conductive electrodes (FTCEs) for flexible electronics. However, it remains a challenge to establish reliable connections between AgNWs and polymeric surfaces to enhance the flexibility of FTCEs without altering their transparency. Herein, a bifunctional interfacial engineering strategy was proposed, synergizing covalent anchoring and passivation shielding to concurrently achieve flexibility, silver migration suppression, environmental stability, and retained optical transparency. A polyethylene terephthalate (PET) surface was decorated via carbene, which could be inserted into C–H bonds instantaneously with chain propagation hardly observed, forming a quasi-monolayer of thiol groups covalently bonded to the topmost layer of the PET substrate, without altering transparency. The adhesion strength between the AgNWs and the PET surface was greatly enhanced by Ag–S bonds. Thus, theAgNW network adhesion and sheet resistance showed no significant change after 100 seconds of ultrasonic treatment in DI water and 1000 times folding, respectively. The surface decoration simultaneously endowed the prepared FTCEs with high visible light transparency (85%), low sheet resistance (11.5 Ω sq⁻¹) and high infrared reflectivity (65%). Fluorinated alkyl chains were covalently decorated on the prepared FTCEs through Ag–S bonds, protecting the electrode from moisture, which effectively suppressed Ag migration. The presented surface modification strategy provides a robust solution for constructing AgNW-based FTCEs with long-term stability.