Material Properties of MOSD Derived Ba_(1-x)Sr_xTiO_3-Based thin films for Pyroelectric Sensor Applications

摘要

BaSrTiO_3 (BST) thin films with a nominal composition of Ba_(0.60)Sr_(0.40)TiO_3 and BST thin films doped with magnesium, aluminum, lanthanum and tantalum (0-20.0 mol percent for Mg and 1.0 mol percent for the Al, La and Ta dopants) were synthesized via the metalorganic solution deposition (MOSD) technique in order to investigate their potential for use as the active material in uncooled infrared (IR) detector applications. The films were characterized for structural, microstructural, compositional, surface morphological, dielectric and insulating properties. The Materials Detectivity Figure of Merit (FOM), D*, [D* = pi/(CV(epsilon _0 epsilon_r tan delta)~(1/2)] was used to evaluate the film's detectivity response. Our results suggest that undoped Ba_(60)Sr_(40)TiO_3, with a value of D*= 0.08 (cm~3/J)~(1/2), appears to out perform Pb based pyroelectric thin films, thus making it a viable candidate for IR pyroelectric detector applications. In addition the preliminary dielectric response studies of the 5 mol percent Mg doped BST and 1 mol percent La doped BST thin films indicate that these two materials are also excellent potential IR material candidates.