Journal article
Spin and magnetic field effects in organic semiconductor devices
IEE proceedings. Circuits, devices, and systems, Vol.152(4), pp.385-392
08/01/2005
DOI: 10.1049/ip-cds:20045226
Abstract
The authors describe three spin and magnetic field effects in organic semiconductor devices: First, injection, transport and detection of spin-polarised carriers using an organic semiconductor as the spacer layer in a spin-valve structure, yielding low-temperature giant magnetoresistance effects as large as 40%. Secondly, spin-dependent exciton formation: pairs of electrons and holes show different reaction rates (the reaction products being spin singlet or triplet excitons, respectively) dependent on whether they recombine in spin-parallel or spin-antiparallel orientation. It is believed that this effect ultimately determines the maximum possible electroluminescent efficiency of organic light-emitting diodes (OLEDs). And, finally, a large magnetoresistance (MR) effect in OLEDs in weak magnetic fields that reaches up to 10% at fields of 10mT at room temperature. Negative MR is usually observed, but positive MR can also be achieved under certain operation conditions. The authors present an extensive experimental characterisation of this effect in both polymer and small molecular OLEDs. The last two effects do not, to the authors' best knowledge, occur in inorganic semiconductor devices and are therefore related to the peculiarities of organic semiconductor physics. The authors discuss their findings, contrasting organic and inorganic semiconductor physics, respectively.
Details
- Title: Subtitle
- Spin and magnetic field effects in organic semiconductor devices
- Creators
- M Wohlgenannt - University of IowaZ V Vardeny - University of UtahJ Shi - University of UtahT L Francis - University of IowaX M JiangO Mermer - University of IowaG Veeraraghavan - University of IowaD Wu - University of UtahZ H Xiong - University of Utah
- Resource Type
- Journal article
- Publication Details
- IEE proceedings. Circuits, devices, and systems, Vol.152(4), pp.385-392
- Publisher
- Inst Engineering Technology-Iet
- DOI
- 10.1049/ip-cds:20045226
- ISSN
- 1350-2409
- Number of pages
- 8
- Language
- English
- Date published
- 08/01/2005
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984428813702771
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