Examining the Mechanism of Current Conduction at Varying Temperatures in Polyimide Nanocomposite Films

Abstract

Charge injection and conduction are fundamental phenomena that occur in dielectric materials when subjected to both low and high electric fields. This paper delves into the exploration of various conduction mechanisms, including space-charge-limited current (SCLC), Schottky charge injection, Poole–Frenkel, and hopping charge conduction, to elucidate the prevailing conduction mechanism in single and multilayer polyimide (PI)/SiO2 nanocomposite films across a range of temperatures. At elevated electric field strengths, the conduction behavior transitions from ohmic to exhibiting a non-linear current–voltage dependence. The investigation highlights that PI nanocomposite films display distinct conduction behaviors contingent on both the applied electric field and temperature conditions. The insights derived from this study provide valuable empirical groundwork and explanations for conducting current measurements in PI-based insulation systems, particularly in applications such as motor insulation for electric vehicles.

Electrical Conduction Mechanisms in Ethyl Cellulose Films under DC and AC Electric Fields

“…The second trapping mechanism is identified as a chemical or deep trap, and is related to the formation of free radicals, chemical cross-linking, or breakage of covalent bonds; the energy associated with these traps has been reported as >1 eV. Several physical models are proposed in the literature for describing and understanding the nonlinear behavior and conduction mechanisms in polymeric materials: conduction mechanisms through the electrode–polymer interface (Schottky and Fowler–Nordheim) and those corresponding to the bulk (Poole–Frenkel, Space Charge Limited Current SCLC and Ionic-Hopping) [ 17 , 18 , 19 ].…”