Magnetic Field-Dependent Electroluminescence in Organic Polymer with Ferromagnetic Cobalt Nanocluster Electrode

Journal Article · Mon Jan 01 00:00:00 EST 2007 · Physical Review B

DOI:https://doi.org/10.1103/PhysRevB.75.075413· OSTI ID:931942

Wu, Yue ^[1]; Li, An-Ping ^[1]; Howe, Jane Y ^[1]; Shen, Jian ^[1]; Hu, Bin ^[1]

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1. ORNL

We report a spin-polarized hole injection into organic semiconductor poly[2-methoxy-5-(2{prime}-ethylhexyloxy)-1,4-]phenylenevinylene (MEHPPV) layer from cobalt (Co) nanoscale clusters based on electroluminescence (EL) studies at liquid nitrogen temperature. The magnetic field effect on EL intensity indicates that the spin injection essentially increases the singlet-to-triplet exciton ratio in organic semiconductors. The Co size-dependent EL shows that the spin-injection efficiency decreases rapidly when the Co clusters percolate to a continuous film. The thickness-dependent EL enhancement of magnetic field suggests that the diffusion length of spin-polarized holes is about 60 nm in the MEHPPV.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Temperature Materials Lab. (HTML)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 931942
• Journal Information: Physical Review B, Vol. 75, Issue 7; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COBALT
DIFFUSION LENGTH
EFFICIENCY
ELECTRODES
ELECTROLUMINESCENCE
EXCITONS
MAGNETIC FIELDS
NITROGEN
ORGANIC POLYMERS
ORGANIC SEMICONDUCTORS
SPIN