Pre-photoexcitation Effects in Ion Irradiated Kapton-H Polyimide

The pre‐photoexcitation effect has been measured in the form of dark polarizarion under visible radiation in 75 MeV oxygen ion irradiated kapton‐H polyimide. The variation of dark decay characteristics has been studied at different polarizing fields. The nature of the decay shows the presence of shallow and deep energy traps in the structure of kapton‐H polyimide. High energy ion irradiation causes the demerization of carbonyl groups and formation of free radicals which results in the increase in charge trapping density.