Voltage decay time of a liquid crystal cell submitted to a large difference of potential

The voltage decay time of a nematic liquid crystal cell submitted to a large difference of electrical potential is theoretically investigated. The authors show that ions are responsible for a current transient in the electrical circuit containing the cell. The analysis is performed by solving the equations of continuity for the ions and the equation of Poisson for the electrical potential. The results of the authors' numerical analysis are compared with the experimental data and a good agreement is found. From the best fit of the experimental data the authors obtain the ionic mobility and the bulk density of ions, in thermodynamical equilibrium. (c) 2006 American Institute of Physics.