Self-polarization Mechanism in Textured Pyroelectric Pb(Ti1-xZrx)O3 films

Abstract

AbstractSelf-polarization of Pb(Ti1−xZrx)O3 (PZT) thin films is explained on the basis of the formation of a TiO2−x-enriched interlayer close to the bottom electrode. Electrons provided by oxygen vacancies generate a n-type interface layer in the PZT at the electrode. A graded ferroelectric layer is then formed by electron injection from the bottom electrode and electron trapping on Ti4+ ions. A “built-in” difference in free energy forms which acts to pole the ferroelectric. Band bending was observed by contact potential difference measurements at a distance of 70 to 90 nm from the bottom electrode.