Electrocaloric Effect of P（VDF-TrFE）/SrTiOa Bilayer Thin Films

A phenomenological thermodynamic theory is applied to investigate the effect of misfit strgin and electric field on the electrocaloric effect of P（VDF-TrFN）/SrTiO3 bilayer thin films. Theoretical results indicate that the low electric field results in the decrease of the average polarization with the increase of the relative thickness of SrTi03 layer, and the high electric field has an opposite effect on it. Moreover, the electroealoric effect strongly depends on the electric field. The low electric field and the small field change can lead to a maximum of the electrocaloric effect, meanwhile the high electric field or the large field change results in the opposite trend.