Pyroelectricity in Poled Thin Films of Aromatic Polyurea Prepared by Vapor Deposition Polymerization

Aromatic polyurea films with a thickness of less than 1 µm were prepared by vapor deposition polymerization using different kinds of aromatic diamine and diisocyanate monomers. After poling above the glass transition temperature, the films acquired a pyroelectric activity of (1.0–2.5)×10 -5 C/m 2 K, which is comparable to that of polyvinylidene fluoride. The temperature limit for the activity was 150 to 200°C, depending on the kind of monomer. The multilayer films consisting of aromatic polyurea and aluminum electrodes showed a high sensitivity proportional to the number of layers.