Flexible, Conductive, and Transparent Polytetrafluoroethylene/AgPdCu/InZnO Hybrid Electrodes for Transparent and Flexible Thin-Film Heaters

Highly flexible, transparent, and conductive polytetrafluoroethylene (PTFE)/AgPdCu (APC)/indium zinc oxide (IZO) hybrid films are developed for use in transparent and flexible thin-film heaters (FTFHs) integrated into electric vehicles. By controlling the thickness of each layer, PTFE/APC/IZO multilayer electrodes with a low sheet resistance of 9.73 Ω/sq and high transmittance of 80.08% at a wavelength of 550 nm and outstanding mechanical flexibility even though it is prepared at room temperature is obtained. In multilayer electrodes, each component plays a specific role, this is, IZO acts as a transparent barrier, APC is the main conduction path, and PTFE is the adhesive layer. Notably, the optimal PTFE/APC/IZO multilayer exhibited superior mechanical flexibility compared with that of the IZO/Ag/IZO multilayer owing to the soft PTFE adhesive layer. The FTFH with the optimized PTFE/APC/IZO multilayer demonstrated a high saturation temperature of 101.9 °C at a low input voltage of 12 V owing to the low sheet resistance and stability provided by the IZO barrier layer. Therefore, the PTFE/APC/IZO hybrid electrodes prepared via a continuous sputtering process provide an effective strategy for achieving high-performance transparent FTFHs for next-generation electric vehicles.