Fabrication of a foldable transparent conductive electrode with suppressed silver migration based on the anchoring of fluorinated alkyl passivated silver nanowire on the PET surface

Abstract

The tethering of silver nanowires (AgNWs) on the optical polymeric membrane is regarded as one of the most applicable strategies constructing flexible transparent conductive electrodes (FTCEs) meeting the growing demand from flexible electronics. However, it remains a challenge to establish reliable connections between AgNWs and polymeric surface enhancing the foldable stability of FTCEs without alternating the transparency. Herein, a bifunctional interfacial engineering strategy was proposed, synergizing covalent anchoring and passivation shielding to concurrently achieve folding stability, silver migration suppression, environmental stability, and retained optical transparency. Polyethylene terephthalate (PET) surface was decorated via carbene, which was able to insert to C-H bonds instantaneously with the chain propagation hardly observed, forming the quasi-monolayer of thiol groups covalently connected with the most top layer of the PET substrate, without altering the transparency. The adhesion strength between AgNWs and PET surface was greatly enhanced by the Ag-S bonds, where the AgNWs surface frame and the sheet resistance showed no significant change after 100 seconds ultrasonic treatment in DI water and 1000 times folded, respectively. The surface decoration endowed the prepared FTCEs with high visible light transparency (85%), low sheet resistance (11.5 Ω/sq) and high infrared reflectivity (65%) simultaneously. Fluorinated alkyl chains were covalently decorated on the prepared FTCEs, forming the Ag-S bonds and protecting the electrode from the invasion of moisture, which effectively suppressed Ag migration. The presenting surface modification strategy provides a robust solution for constructing long-term stable AgNWs based FTCEs.