On the origin of polarization fatigue and Curie–von Schweidler relaxation current in Pb(Zrx,Ti1−x)O3 ferroelectric thin films: A unique mechanism based on charge trapping by interface defects

Abstract

This article discusses the widespread problem of polarization fatigue in ferroelectric materials. After a review of the bibliographical data on this topic but also on the older and equally widespread problem of dielectric relaxation in solids, a possible correlation between these two phenomena is established by observing that the decrease with time of polarization obeys the Curie–von Schweidler (CVS) law like the relaxation current. An electrical model involving a charge trapping mechanism by electronic defects in bandgap at the contact/ferroelectric interface is then developed, which simultaneously explains polarization fatigue and relaxation current. The CVS law is found considering interface traps with a continuum of time constants. This study sheds new light on the origin of these phenomena, which remain unexplained to date.