Low-Heat-Driven Self-Healing Flexible Electrochromic Film Relying on a PEDOT:PSS-Based All-Organic Composite

Abstract

Electronic materials capable of bionic self-healing have received extensive attention in view of the urgent need of extending device life, maintaining operation safety, and reducing renewal costs. Among them, conducting polymers (CPs), especially poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PE-DOT:PSS), have become a research hotspot due to their intrinsic and tunable electrical conductivity, macromolecule nature with good processability, good stability, combination ability, etc. Herein, an all-organic PEDOT:PSS/poly-(ethylene glycol)/2-amino-4-hydroxy-6-methylpyrimidine-encapsulated polyurethane film with high electrical conductivity, remarkable self-healing ability, excellent mechanical flexibility, and strong water resistance is created by the ingenious design of a multiple hydrogen-bonding strategy. Moreover, the film was fabricated easily from a solvent (water/methanol)-processable dispersion with fast drying and "green" advantages. The film crack can be healed by relatively lowtemperature heating at 65 °C for 5 min with recovered smooth surface and electrochromic properties, including high optical contrast (ΔT) values of up to 68.2%, fast oxidation and reduction responses (0.24 and 0.49 s, respectively), and excellent coloration efficiency (246.4 cm 2 C −1 ). The flexible electrochromic device employing this film as an active layer still maintained an ΔT value of more than 47% and can remain above 90% even after 1000 times of operation or mechanical bending. This research will greatly enhance the reliability of PEDOT:PSS-based organic film electronic devices.