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.