Carrier lifetime and spin relaxation time study for electrical spin injection into GaAs.

Authors :: Oh, Eunsoon
Lee, T. K.
Park, J. H.
Choi, J. H.
Park, Y. J.
Shin, K. H.
Kim, K. Y.
Source :: Journal of Applied Physics; Aug2009, Vol. 106 Issue 4, p043515-043519, 4p, 3 Graphs
Publication Year :: 2009
Abstract: We fabricated spin light emitting diodes using oxide tunneling barriers between ferromagnetic materials (Ni<subscript>0.8</subscript>Fe<subscript>0.2</subscript>/Co<subscript>0.9</subscript>Fe<subscript>0.1</subscript>) and semiconductors (GaAs) and investigated the temperature-dependent carrier lifetime and spin relaxation time of the active GaAs layer. We observed the circular polarization of the free exciton from the electroluminescence spectra due to the spin injection from the ferromagnetic material, whereas the circular polarization of the conduction band to acceptor transition was negligible. From the temperature-dependent carrier lifetime and spin relaxation time of the active GaAs layer, we found that the spin injection efficiency was larger than 25% between 20 and 180 K, where the magnetic field dependence of the spin lifetime was ignored. [ABSTRACT FROM AUTHOR]

Subjects :: RELAXATION (Nuclear physics)
LIGHT emitting diodes
QUANTUM tunneling
POLARIZATION (Nuclear physics)
CONDUCTION bands
MAGNETIC fields

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