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

Abstract

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.