Evidence for different origins of the magnetic field effect on current and electroluminescence in organic light-emitting diodes

An external magnetic field can change the current through an organic light-emitting diode and the luminance it emits. Existing models predict that both phenomena have the same behaviour and, therefore, a common origin; however, there are indications that they are not completely linked. As a direct proof, we measured the magnetic field effect in multilayer organic light-emitting diodes using Alq(3) as emission layer. After successively adding blocking layers, we found a decrease of the magnetic field effect on the current, whereas the effect on the luminance remained at the same level. Thus, both effects can be separated from each other. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3696051]