Journal article
Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields
Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences, Vol.373(2044), p.20140326
06/28/2015
DOI: 10.1098/rsta.2014.0326
PMCID: PMC4455723
PMID: 25987575
Abstract
Until recently the important role that spin-physics (‘spintronics’) plays in organic light-emitting devices and photovoltaic cells was not sufficiently recognized. This attitude has begun to change. We review our recent work that shows that spatially rapidly varying local magnetic fields that may be present in the organic layer dramatically affect electronic transport properties and electroluminescence efficiency. Competition between spin-dynamics due to these spatially varying fields and an applied, spatially homogeneous magnetic field leads to large magnetoresistance, even at room temperature where the thermodynamic influences of the resulting nuclear and electronic Zeeman splittings are negligible. Spatially rapidly varying local magnetic fields are naturally present in many organic materials in the form of nuclear hyperfine fields, but we will also review a second method of controlling the electrical conductivity/electroluminescence, using the spatially varying magnetic fringe fields of a magnetically unsaturated ferromagnet. Fringe-field magnetoresistance has a magnitude of several per cent and is hysteretic and anisotropic. This new method of control is sensitive to even remanent magnetic states, leading to different conductivity/electroluminescence values in the absence of an applied field. We briefly review a model based on fringe-field-induced polaron-pair spin-dynamics that successfully describes several key features of the experimental fringe-field magnetoresistance and magnetoelectroluminescence.
Details
- Title: Subtitle
- Singlet-to-triplet interconversion using hyperfine as well as ferromagnetic fringe fields
- Creators
- M Wohlgenannt - University of IowaM. E Flatté - University of IowaN. J Harmon - University of IowaF Wang - University of IowaA. D Kent - New York UniversityF Macià - New York University
- Resource Type
- Journal article
- Publication Details
- Philosophical transactions of the Royal Society of London. Series A: Mathematical, physical, and engineering sciences, Vol.373(2044), p.20140326
- Publisher
- The Royal Society Publishing
- DOI
- 10.1098/rsta.2014.0326
- PMID
- 25987575
- PMCID
- PMC4455723
- ISSN
- 1364-503X
- eISSN
- 1471-2962
- Alternative title
- Spin-conversion by nuclear/fringe fields
- Language
- English
- Date published
- 06/28/2015
- Academic Unit
- Electrical and Computer Engineering; Physics and Astronomy
- Record Identifier
- 9984199839102771
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