High-energy density in aromatic polyurea thin films

This letter investigates dielectric responses of aromatic polyurea thin films fabricated through vapor deposition polymerization. The high quality polymer films exhibit high breakdown field (800 MV/m) and high-energy density (>12 J/cm³) at room temperature. These values decrease slightly from room temperature to 180 °C. Linear dielectric responses were found in the films even under high fields and high temperatures with a high charge-discharge efficiency (>90%). These high performance features make aromatic polyurea attractive for high-energy density capacitors, especially under high temperatures.