Dielectric and current-voltage characteristics of flexible Ag/BaTiO₃ nanocomposite films processed at near room temperature

High dielectric constant ceramic-polymer composite materials have been produced by thermal-treatment in the range of 160 to 200 °C. Here, we introduce a room temperature process of generating flexible high dielectric constant nanocomposite films on a polymer substrate by combining a printing technique with a UV-curing process. The composite structure is based on nanoscale BaTiO₃ and Ag particles dispersed in a UV-cured polymer matrix. Dielectric characteristics of the nanocomposite thick films depended on the volume fraction and particle size of BaTiO₃ as well as the content of Ag. As an optimal result, a dielectric constant of ∼300 and a dielectric loss of 0.08 were achieved when ∼81 nm BaTiO₃ and ∼34 nm Ag particles were used in a total volume fraction of 56.2%, which are very competitive for flexible capacitive devices. Current-voltage behavior of the nanocomposite films depended largely on the content of Ag content as related to the percolative transition of electrical conduction.