Abstract
Barium strontium titanate (Ba1-xSrxTiO3, BST) thin film is one of the most promising materials for infrared detectors because of its high dielectric constant and pyroelectric coefficient. In order to reduce material thickness and increase detector sensitivity, Ba1-xSrxTiO3 thin films were prepared by an RF magnetron co-sputter technique. Here, we present results on relationships between composition, microstructures, electrical properties and pyroelectric coefficient for polycrystalline BST films. Applying negative DC bias on substrate holder during sputtering can enhance the crystallinity of BST Films. A curie point of about 22℃, which is close to room temperature, is obtained for the Ba0.73Sr0.27TiO3 film. The Ba0.73Sr0.27TiO3 film possesses a pyroelectic coefficient of about 13.69 nC/cm2℃.