Magnetic field modulated exciton generation in organic semiconductors: An intermolecular quantum correlated effect

Magnetoelectroluminescence (MEL) of organic semiconductor has been experimentally tuned by adopting blended emitting layer consisting of hole transporting material and electron transporting material. Theory based on Hubbard model fits experimental MEL well, which reveals two findings: (1) spin scattering and spin mixing, respectively, dominate MEL in low-field and high-field region. (2) Blended ratio, and thus the mobility, determines the value of the relative change in the EL in a given magnetic field. Finally successful prediction about the increase in singlet excitons in low field with little change in triplet exciton population further confirms the first finding.