Journal article
Impurity-band transport in organic spin valves
Nature communications, Vol.5(1), pp.4842-4842
09/09/2014
Handle:
https://hdl.handle.net/2376/110416
PMID: 25203690
Abstract
The central phenomenon in the field of organic spintronics is the large magnetoresistance in thick organic spin valves. A prerequisite for understanding the magnetoresistance is a reliable description of the device resistance, or the I-V characteristics. Here I show that the observed I-V characteristics in the organic spin valves is incompatible with charge injection into the organic's lowest unoccupied molecular orbital or highest occupied molecular orbital but can be explained by electrons tunnelling into a broad impurity band located in the gap between these molecular orbitals. Voltage drop takes place mainly across depletion layers at the two electrode/organic interfaces, giving rise to electrode-limited charge transport. Spin-dependent electron tunnelling into the impurity band from the ferromagnetic electrodes results in spin accumulations inside the organic, which rapidly diffuses through the organic primarily via the exchange between impurity-band electrons. This picture explains the major magnetoresistance features and predicts enhanced capacitance in these devices.
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Details
- Title
- Impurity-band transport in organic spin valves
- Creators
- Z G Yu - Physical Sciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, California 94025, USA
- Publication Details
- Nature communications, Vol.5(1), pp.4842-4842
- Academic Unit
- Institute for Shock Physics
- Publisher
- England
- Identifiers
- 99900547018701842
- Language
- English
- Resource Type
- Journal article