Extrinsic Thermally Stimulated Currents in FEP Films with Ion-Plated Aluminum Electrodes

Thermally stimulated currents and "scanning temperature conduction currents" are studied in FEP thin films with ion plated aluminum electrodes (Al*). In these films, a rapid increase in the positive charge flow Ip from the interfacial region between Al* and FEP into the bulk of FEP is observed at elevated temperatures. This rapid increase in Ip begins at lower temperatures as the accelerating voltage Va for the ion plating increases. In negatively corona-charged FEP films with Al*, three TSC peaks appear depending on Va. The highest-temperature peak of the three is the extrinsic one originating from neutralization of the trapped charges by Ip. The annealed samples show only the extrinsic TSC because of the low thermal stability of the trap sites which are responsible for the intrinsic TSCs.