Determination of drift mobilities of impurity ions in nematic liquid crystal cells from transient current induced by polarity reversal voltage pulses

Abstract

Drift mobilities of impurity ions in nematic liquid crystal cells have been estimated from a peak time in current transients measured by a voltage reversal method. A Monte-Carlo computer simulation has been carried out to show that the peak time is dependent on the frequency of the polarity-reversal voltage pulses and that the drift mobilities measured in this way are overestimated. A method is suggested to correctly measure both drift mobilities and diffusion constants of impurity ions by fitting computer-generated tramsients to experimentally obtained transients.