Magnetic field-modulated exciton generation in organic semiconductors: an intermolecular quantum correlation effect

TL;DR

This paper presents a theoretical model explaining how magnetic fields influence exciton generation in organic semiconductors through intermolecular quantum correlations, highlighting the roles of spin mechanisms and carrier hopping rates.

Contribution

It introduces a novel theoretical framework that incorporates intermolecular quantum correlations to explain magnetic field effects on exciton generation in organic semiconductors.

Findings

Magnetic field modulates exciton generation via spin scattering and spin mixing.

Hopping rate of carriers influences the intensity of magnetoelectroluminescence.

Model predicts increased singlet excitons at low magnetic fields with minimal change in triplet excitons.

Abstract

Magnetoelectroluminescence (MEL) of organic semiconductor has been experimentally tuned by adopting blended emitting layer consisting of both hole and electron transporting materials. A theoretical model considering intermolecular quantum correlation is proposed to demonstrate two fundamental issues: (1) two mechanisms, spin scattering and spin mixing, dominate the two different steps respectively in the process of the magnetic field modulated generation of exciton; (2) the hopping rate of carriers determines the intensity of MEL. Calculation successfully predicts the increase of singlet excitons in low field with little change of triplet exciton population.