Electrode effect on electrical conduction in thin film of polyvinyl pyrrolidone

Abstract

Electrical conduction behaviour in ployvinyl pyrrolidone (PVP) has been investigated in both transient and steady state conditions in the temperature range 40-80°C at different <i>dc</i> electric fields from 05 to 100 kV/cm using similar and dissimilar, both types of electrode systems. The nature of transient currents has mainly been attributed to the dipolar nature of PVP in the lower temperature region where slope value <i>n</i> of the Curie Von Schweidler law is found to vary from 0.43 to 0.62 for similar electrode system and from 0.78 to 0.98 for dissimilar electrode system. The low field steady state conduction is found to be ohmic in nature. The high field non-linear nature of conduction currents is found to be strongly temperature dependent and an attempt has been made to explain these curves taking into account various conduction processes. A strong temperature dependence of the conduction current rules out tunnelling as the possible conduction mechanism. The Poole-Frankel and Richardson-Schottky coefficients estimation shows that Richardson-Schottky conduction mechanism is operative in controlling the transport of charges in PVP foil electrets. This result is, further, confirmed using different electrodes systems of Jonscher and Ansari.