Enhanced performance of sandwich structure Pb0.8La0.1Ca0.1Ti0.975O3 thin film for pyroelectric applications

Using the advantages of low-temperature crystallization and high orientation in Pb0.8La0.1Ca0.1Ti0.975O3 (PLCT) film, a dense PLCT/porous PLCT/dense PLCT sandwich structure was obtained in the present study. It is found that dense PLCT layer can both sustain the porous density in the core layer and also lead to better preferential orientation of the sandwich structure. In the sandwich structure, low dielectric constant (epsilon(r)=43) and leakage current density (J<9 x 10(-5)A/cm(2)) are simultaneously achieved. Because of high orientation in sandwich structure, the pyrocoefficient (p>185 mu C/m(2) K) is still keeping a relatively large value. The resulting high figure of merit (F-V'=4.5 mu C/m(2) K, F-d'=228 mu C/m(2) K) make the sandwich structure films good candidate for pyroelectric thin-film devices. (C) 2009 Elsevier B.V. All rights reserved.