Simulation of organic light-emitting diodes

Despite the progress made in improving device performance, fundamental questions remain about the nature of conduction mechanisms in organic electroluminescent devices (OLEDs) and the relationship between current, voltage and luminance. This paper will address these issues by a theoretical study of one and two layer OLEDs. Carrier mobility, extrinsic dopant density, bulk trap/interface state energy and density measurements will be taken from experimental data. The measured current–voltage characteristics have been modelled with a drift diffusion code using these measurements as input parameters. The transport mechanisms, free and trapped carrier density profiles, and recombination rate profiles have been obtained and correlated with internal field measurements, where available. The effect of varying such parameters as the mobility has been explored.