Analysis and interpretation of photo-stimulated discharge spectrum for polypropylene films under different electric and geometrical conditions

Experiments on polypropylene films under different electric and geometrical conditions are carried out to investigate various causes that would affect the interpretation of photo-stimulated discharge spectrum. The samples used in the experiment are metalized with finger-like shape or circular shape electrodes. The results show that the occurrence of photoemissions from electrode or polymer at wavelengths less than about 260 nm is possible, depending on the polarity and amplitude of applied voltage. The photocurrent spectra for samples with circular electrodes characterize two charge de-trapping peaks and the peak at 273 nm is also partially contributed by the photoelectrons from electrode.