Surface conduction behaviour of 100 Mev Si ion irradiated kapton-H polyimide

Abstract

The surface conduction behaviour of kapton-H polyimide irradiated with 100 MeV Si⁺ ion (Fluences 2.3 × 10¹¹, 2.3 × 10¹² and 1.3 × 10¹³ ions/cm²) has been investigated in the temperature range 21 to 150°C. The current-voltage (I-V) characteristics in the low field region i.e., below 10 kV/cm show ohmic behaviour whereas non-linearity occurs in the high field region. The non-linear region is temperature dependent. The nature of I-V characteristics of pristine kapton-H samples doesn’t differ much from the irradiated samples suggesting that the surface charge conduction mechanisms are not much affected due to irradiation. The ionic jump distance estimations (3–18 Å) supports to ionic conduction process below 110°C. The Poole-Frenkel and Schottky coefficient estimations show that Poole-Frenkel and Schottky conduction mechanisms are operative at moderate and low temperatures, respectively. The observed change in surface resistivity (ρ) in the irradiated samples has been associated to the increase in delocalized π-electrons and cross-linking.