Photo-stimulated discharge current measurements on biaxially oriented polypropylene thin films (BOPP)

The photo-stimulated discharge method (PSD) is a very good tool to estimate charge trap energy levels in transparent or semi-transparent materials. Its advantage, when compared to thermally stimulated discharge (TSD), is to probe deeper charge traps without any thermal effect that can affect the material microstructure and the charge stability. In this work, PSD measurements were performed on biaxially oriented polypropylene films. The PSD spectrum shows two peaks located at 400nm and 240nm scanning light wavelength. The effect of the electrode structure (fingered vs. continuous electrodes) and the effect of applied field intensity are discussed.