Mechanism of charge exchange at a liquid crystal-electrode interface

It is shown that liquid crystal-electrode charge exchange is accomplished via the mechanism of Schottky emission through a thin dielectric layer. The thin dielectric layer (several nanometers) is formed by adsorption of neutral molecules that either are introduced on purpose or occur in even well-purified liquid crystals. The main part of the barrier determining the charge exchange process is due to the ionization of the cation losing an electron and its transformation to the anion. The barrier parameters and the dielectric layer thickness are estimated for the planar and homeotropic alignments of molecules. (C) 2000 MAIK "Nauka/Interperiodica".