Highly polarized emission from electrical spin injection into an InGaAs quantum well with free carriers
- Naval Research Laboratory, Washington, D.C., 20375 (United States)
- Department of Materials Science and Technology, University of Crete, Heraklion Crete 71003 (Greece)
- SUNY Buffalo, Buffalo, New York 14260 (United States)
- Quantum Theory Group, Emerging Technologies Division, National Research Council, Ottawa K1A0R6 (Canada)
We report on a highly polarized emission from InGaAs/GaAs-quantum well light-emitting diodes in which we inject spin-polarized electrons from an Fe/Schottky contact. The emission spectra consist of the e{sub 1}h{sub 1} free exciton (FX) and a feature 12 meV below FX attributed to band-to-band (BB) recombination. The FX exhibits a maximum circular polarization of 22%, with a magnetic-field dependence characteristic of spin injection from Fe. The BB emission on the other hand exhibits a polarization that is strongly bias and temperature dependent, with intriguing magnetic-field dependence: The polarization exhibits a maximum of 78% at 2.5 T and 2 K, then decreases linearly with field and reaches −78% at 7 T, attributed to magnetic-field dependent spin relaxation in the presence of excess electrons.
- OSTI ID:
- 22254019
- Journal Information:
- Applied Physics Letters, Vol. 103, Issue 21; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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