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

TL;DR

This paper predicts that patterned ferromagnetic films can significantly enhance the electroluminescence of organic LEDs by manipulating fringe magnetic fields, offering a new way to control light emission and encode information.

Contribution

It introduces a full theoretical framework for how magnetic domain structures influence spin-mixing and electroluminescence in organic LEDs, surpassing effects of uniform magnetic fields.

Findings

Electroluminescence can be increased by up to a factor of two using patterned magnetic domains.

Optimal ferromagnetic film patterns are identified for maximum luminescence enhancement.

The theory links magnetic domain structures to spin-mixing processes affecting light emission.

Abstract

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.