Conduction mechanism in antiferrolectric PbZrO₃ thin films-analysis of charge carrier trapping phenomenon

Abstract

Antiferroelectric compositions, such as PbZrO₃, are attractive candidates in charge storage devices and actuator/transducer applications in MEMs technology. Thin films of PbZrO₃ were deposited on Pt coated Si substrates by a pulsed excimer ablation process. The process of field induced ferroelectric phase switching involves the domain wall reorientation in the polycrystalline thin films. The presence of grain boundaries and various defects in the polycrystalline thin films acts as the pinning sources for the various domain walls. These defects capture the charge carriers in the presence of external applied field and hinders further switching of the dipoles in the domains, thereby increases the response times and threshold voltages for the devices operations. Understanding of the trapping phenomenon in these films is very essential. Using Lampert's theory of space charge limited conduction both shallow and deep trap energies were estimated approximately from charge transport analysis.