Engineering Temperature‐Switchable Conducting Metal–Phenolic Network Films

Designing energy-efficient materials capable of transitioning between insulating and conducting states with ultrahigh ON/OFF ratios is a key challenge in advancing electronic materials. Herein, a class of materials exhibiting temperature-tunable insulator-metal transitions based on the facile chemistry of metal-phenolic networks (MPNs) is reported. Enhanced π-π stacking in the materials at elevated temperatures triggers a transition from insulating to highly conductive states, as confirmed experimentally and by molecular dynamics simulations. The MPN films (∼10-300 nm thick) exhibit ultrahigh OFF-state resistance, tunable transition temperatures (354-504 K), ultrafast switching speeds (<1 µs), high ON-state Hall mobility (117 cm² V^-1 s^-1), scalability (>18 cm²), tunable electrical properties (via ligand and metal choice), and compatibility with diverse electronic devices and circuits. This work offers a pathway to developing low-cost, customizable material platforms for smart electronics.