Conduction mechanism in electron beam-irradiated unplasticized PVC/PVA copolymer films under high electric field

In the present work, the conduction mechanism in the electron-irradiated unplasticized poly(vinyl chloride) (UPVC)/poly(vinyl alcohol) (PVA) films has been investigated by measuring their I−V characteristic curves. The I−V measurements have been carried out at applied electric fields up to 20 kV/cm. Specimens of UPVC/PVA of 230 μm thickness were irradiated with a 1.5 MeV electron beam in air to different doses of 30, 135, 540 and 1080 kGy, respectively. The I−V characteristics for the films show a direct proportionality between the current values and the irradiation dose. The temperature dependence of the I−V characteristics (in the temperature range of 293–353 K) has also been studied. It has been found that the density of the localized state values is inversely proportional to the irradiation dose. The results reveal a non-ohmic behavior in this regime of temperature range providing the existence of space-charge-limited conduction in UPVC/PVA films.