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

Physical review. B, Condensed matter (Impact Factor: 3.66). 11/2009; 82(20). DOI: 10.1103/PhysRevB.82.205209
Source: arXiv


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.

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Available from: Baofu Ding, May 21, 2014
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    • "The origin of the OMR is recognized to be the spin interactions in OSC, such as the hyperfine interaction [13] and the spin–orbit coupling [14]. Several microscopic processes have been proposed to be responsible, including the blocking of carriers by bipolarons [15] and excitons [8], interfacial dissociation of excitons [16], and electron–hole pair mediated processes [10] [17] [18]. Simulations by kinetic Monte Carlo method and stochastic Liouville equations have achieved satisfying comparison with many experimental results. "
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