Links between electrical and optical fatigue in Pb(Zr,Ti)O₃ thin films

Switchable polarization can be significantly suppressed in ferroelectric (FE) materials by electrical or optical processes. Electrical suppression can occur by subjecting the FE to repeated polarization reversals; optical suppression can occur while biasing the FE near the switching threshold and illuminating with bandgap light. A link between the two processes in Pb(Zr,Ti)O₃ (PZT) thin film capacitors is demonstrated by showing a relationship between the amount of the suppressed polarization induced by the two methods. This observation suggests that the optical method may be a useful, simple, and time-saving probe of a material's susceptibility to fatigue. These results further support the view that polarization suppression in PZT thin films induced by electrical fatigue largely involves electronic charge trapping.