Conduction mechanisms and structure-property relationships in high energy density aromatic polythiourea dielectric films

Aromatic polythiourea (ArPTU) is an amorphous, polar, glass-phase dielectric polymer which features extremely high dielectric breakdown strength (>1.1 GV/m), low loss at high electric fields (10% at 1.1 GV/m), and a high maximum electrical energy density (>24 J/cm³). This work presents a study of the structure-property relationships and electrical conduction in ArPTU, and offers a phenomenological explanation for the experimentally observed high-field loss characteristics which facilitate the excellent energy storage properties. Aromatic polythiourea is a dielectric polymer with low high-field loss and excellent electrical breakdown strength (>1.1 GV/m). The dielectric constant of 4.5 and high breakdown strength lead to a high maximum energy density of >24 J/cc in the material. The conduction mechanisms and structure-property relationships, which lead to these properties, are the focus of this work.