Magnetic field effects on the quenching of triplet excitons in exciplex-based organic light emitting diodes

Triplet excited states in exciplex-based organic light emitting diodes (OLEDs) can be wasted by transferring their energy to the host material in a system with smaller triplet energy levels. This triplet loss process is investigated using magnetic field effects (MFEs). Magnetophotoluminescence (MPL) and magnetoelectroluminescence (MEL) are comprehensively studied and the results suggest that this energy transfer can influence the lineshape or amplitude of MPL and the current dependence of MEL. Transient MEL is also studied to examine the influence of the magnetic field on exciton dynamic processes. The experimental results show that the time-resolved MELs at the rising and falling pulse stages will be affected by this triplet energy transfer based on different exciton interactions under an external magnetic field.