High-performance solid capacitor using vapor phase polymerized PEDOT film

Poly (3,4-ethylenedioxythiophene) (PEDOT), an excellent conductive polymer, has made great progress in the preparation process and doping modification, while the research on the reaction mechanism is relatively inadequate. Herein, PEDOT films with different reaction time were prepared by vapor phase polymerization to summarize the mechanisms of structure and performance changes during the growth of PEDOT film. Furthermore, the laminated solid capacitors were prepared and their properties were characterized to prove the reliability of the mechanisms. The research shows that the PEDOT polymerization process can be divided into three different periods: cover period (0–10 min), wrinkle period (10 min–2 h) and amorphous period (after 2 h). The polymer will undergo crystallinity changes when the reaction time is too long (in the amorphous period), resulting in the deterioration of conductivity. Finally, the capacitor based on PEDOT film with a reaction time of one hour had a good performance: capacitance of 450.3 μF, dissipation factor of 2.2%, leakage current of 5.31 μA and equivalent series resistance of 3.71 mΩ, which proves that the mechanisms have high reliability. Graphical abstract Optimized PEDOT film giving a high performance for solid capacitor The formation of the PEDOT wrinkle morphology is caused by the erosion of the EDOT monomer on the oxidant and the lateral stress between the films during the polymerization process.