Electrical conduction in a semicrystalline polyethylene terephthalate in high electric field

Measurements of conduction currents were carried out on polyethylene terephthalate semi crystalline PET in an electrical field region varying from 40 to 260 V/mu m. Various mechanisms of conduction (Richardson-Schottky, Fowler-Nordheim, Poole-Frenkel, space charge limited current SCLC, Hopping), can cause non-linear characteristics. To highlight the mechanism responsible for conduction in the PET, we used the slope of the experimental curve Log(J) =f(E) in the region 150 < E < 260 V/mu m, to calculate the value of the dielectric permittivity. The characteristic curve Log(J) =J(1/T) shows that the Poole-Frenkel mechanism of conduction is prevalent in the semi crystalline PET. The characteristic J=f(E) for various thicknesses shows that the field threshold increases with the thickness. (c) 2006 Elsevier Ltd. All rights reserved.