Imprint Behavior of Piezoelectric PZT Thin Films Deposited onto Cu-Coated Polymer Substrates

In this work, we investigate the imprint behavior of lead-rich Pb(Zr, Ti)O-3 (PZT) thin films deposited onto copper-coated Kapton (R) substrates by piezoresponse force microscopy. As-deposited films, consisting of a mixture of PZT and lead and zirconium oxides, had a strongly imprinted polarization state with a polarization vector pointing toward the film surface. Above a threshold field of about 10 V/mu m, a steeply increasing piezoelectric response without hysteresis was obtained. With increasing voltage cycling, the threshold field increases and a one-sided piezoresponse hysteresis is obtained. The described imprint behavior is related to initially trapped charge carriers and their detrapping under voltage cycling.