A lattice gas approach to conduction in organic material

The current-voltage relationship of organic diodes that are used as organic light emitting devices is reported. Charged molecules are created at the electrodes by an oxidation/reduction reaction. The charge moves across the material by an electron transfer mechanism from a charged molecule to a neutral molecule. The charges are described by a lattice gas because there is a low concentration of charges. The concentration of charged molecules at the electrode is governed by the Nernst equation and is coupled to the equations of transport. The concentration of charge is determined by a competition between charge creation and charge transport. The applied voltage creates the charge at the electrodes and causes charge transport. The graphical analysis results in the charge density and current density as a function of the applied voltage and the dependence of the current density on both temperature and device thickness