Significant polarization variation near room temperature of Ba0.65Sr0.35TiO3 thin films for pyroelectric energy harvesting

Ba0.65Sr0.35TiO3 (BST) thin films with self-buffered layers were prepared on Pt(1 1 1)/Ti/SiO2/Si substrates by chemical solution deposition. The effect of self-buffered layer on the crystal orientation of BST film was studied. Polarization variation with room temperature and harvested energy density of BST film were also investigated. It is found that the (1 0 0) of the BST film with self-buffer layer is more intense than those of the BST film without self-buffer layer. For the BST film with 550 degrees C annealed self-buffer layer, the polarization variation reaches to 5.2 mu C/cm(2) from 77 to 2 degrees C, and the harvested energy density is calculated to be 128 mJ/cm(3) based on the polarization variation using the Ericsson cycles. (C) 2012 Elsevier B.V. All rights reserved.