Pyroelectric properties of BSCT thick films for uncooled infrared detectors

Abstract

Ferroelectric (Ba0.54Sr0.36Ca0.10)TiO3(BSCT) thick films were fabricated by a screen printing method on high purity alumina substrates, and the structural and electrical properties with the variation of the number of screen-printings were examined for uncooled infrared detector applications. The lattice constant of BSCT thick films was 0.3952 nm and there is no dependence on the variation of thickness. The thickness of thick films obtained by one screen-printing was approximately 7 mu m. The relative dielectric constant increased and the Curie temperature decreased with an increase in the number of screen printings, an increase in film thickness. The pyroelectric coefficient of the 9-printed BSCT thick films was 270 x 10(-9) Ccm(-2) K-1 at the Curie temperature. The figures of merit, F-v for the voltage responsivity and F-D for the specific detectivity, of the 9-printed BSCT thick films were 3.1 x 10(-11) Ccm/K and 1.7 x 10(-9) Ccm/K, respectively.