Manipulation of the electroluminescence of organic light-emitting diodes via fringe fields from patterned magnetic domains

We predict very large changes in the room-temperature electroluminescence of thermally-activated delayed fluorescence organic light emitting diodes near patterned ferromagnetic films. These effects exceed the changes in a uniform magnetic field by as much as a factor of two. We describe optimal ferromagnetic film patterns for enhancing the electroluminescence. A full theory of the spin-mixing processes in exciplex recombination, and how they are affected by hyperfine fields, spin-orbit effects, and ferromagnetic fringe field effects is introduced, and is used to describe the effect of magnetic domain structures on the luminescence in various regimes. This provides a method of enhancing light emission rates from exciplexes and also a means of efficiently coupling information encoded in magnetic domains to organic light emitting diode emission.