Conduction Processes in Kapton H Irradiated by an Electron Beam

Current conduction in Kapton H films irradiated by a non-penetrating electron beam was studied by comparing the observed current-voltage characteristics with theoretical models. The functional dependence of the current on the electric field was found to be in relatively good agreement with the dependence predicted by the Poole-Frenkel conduction and Schottkey emission model. A beam energy dependence was observed that is not accounted for by these models. No correlation was obtained with space-charge-limited conduction model that assumes a zero electric field at the injecting electrode. This result was observed both for a field independent conductivity as well as for a Poole-Frenkel conductivity. A modified space-charge-limited conduction model that includes a finite electric field at the injection electrode appears to describe the observed dependence. This model incorporates any beam energy dependence in a natural way through a beam dependent variation in electric field that is predicted to occur at the boundary of the unirradiated region.