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Title: Magnetoelectroluminescence of organic heterostructures: Analytical theory and spectrally resolved measurements

The effect of a magnetic field on the electroluminescence of organic light emitting devices originates from the hyperfine interaction between the electron/hole polarons and the hydrogen nuclei of the host molecules. In this paper, we present an analytical theory of magnetoelectroluminescence for organic semiconductors. To be specific, we focus on bilayer heterostructure devices. In the case we are considering, light generation at the interface of the donor and acceptor layers results from the formation and recombination of exciplexes. The spin physics is described by a stochastic Liouville equation for the electron/hole spin density matrix. By finding the steady-state analytical solution using Bloch-Wangsness-Redfield theory, we explore how the singlet/triplet exciplex ratio is affected by the hyperfine interaction strength and by the external magnetic field. In order to validate the theory, spectrally resolved electroluminescence experiments on BPhen/m-MTDATA devices are analyzed. With increasing emission wavelength, the width of the magnetic field modulation curve of the electroluminescence increases while its depth decreases. Furthermore, these observations are consistent with the model.
Authors:
 [1] ;  [2] ;  [2] ;  [2] ;  [2] ;  [1] ;  [3] ;  [1] ;  [3]
  1. Univ. of Minnesota, Minneapolis, MN (United States)
  2. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  3. (LANL), Los Alamos, NM (United States)
Publication Date:
OSTI Identifier:
1235729
Report Number(s):
LA-UR--14-28083
Journal ID: ISSN 1098-0121; PRBMDO
Grant/Contract Number:
DMR-0819885; AC52-06NA25396
Type:
Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 90; Journal Issue: 23; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society (APS)
Research Org:
Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY organic semiconductors; spintronics