An analytic model of electroluminescence in bilayer organic light emitting diodes with Ohmic injection of charge carriers

A simple analytic model for the electroluminescence (EL) intensity and the total cell current in bilayer light-emitting diodes (LEDs) with Ohmic contacts is presented. Results are in good agreement with both existing experimental data and numerical simulations. This model permits the semiquantitative analyses of the influence of the most important parameters on the EL and cell currents. In particular, dependence of EL current on the ratio of electron to hole mobilities and on the LED geometry is analyzed. The predictions of the model are compared with analogous results for LEDs with barrier-limited injection of electrons. It is shown that the values of EL currents can be comparable. (C) 2001 American Institute of Physics.