Electrical conduction and persistent internal polarization in sisal wax

Abstract

A detailed study of the current as a function of voltage, temperature, and thickness coupled with that of persistent internal polarization under different field and temperature conditions has been undertaken in sisal wax. The study of electrical conduction indicates that all the results are consistent with the assumption of an exponential distribution of trapping states in the band gap which is found to be about 7.38 eV wide. The dependence of the initial and final charge densities on the polarizing field and the temperature, and the decay of initial charge density with time have shown that bulk polarization is due to trapping of both holes and electrons. The slow isothermal charge decay and persistence of charge have been considered to be due to the thermal release of charge carriers from the trapping levels and fast retrapping in the shallow levels.