Efficient injection of spin-polarized electrons from MnAs contacts into GaAs quantum well LEDs

ORAL

Abstract

Recent studies of ferromagnetic MnAs have revealed a wide range of properties desirable for spintronic applications. In this work, ferromagnetic MnAs contacts have been used to inject spin polarized electrons into AlGaAs(n)/GaAs(i)/AlGaAs(p) light emitting diodes. The band-edge electroluminescence emitted from these devices has a saturation circular polarization of 26\% at 7K. The circular polarization was found to track the out of plane magnetization of MnAs, confirming spin injection. Using optical pumping measurements, the corresponding electron spin polarization was determined to be 52\%. Emission persists up to room temperature, with a saturation circular polarization of 6\%. The improved performance over similar structures is attributed to the use of MnAs/AlGaAs Schottky barrier tunneling and minimal interdiffusion of Mn ions near the materials interface.

*Work at SUNY was supported by NSF, ONR, and the Rustgi professorship.

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Authors

  • E.D. Fraser

    • University at Buffalo, The State University of New York

  • Shridhar Hegde

    • University at Buffalo, The State University of New York

  • Lars Schweidenback

    • SUNY Buffalo
    • University at Buffalo, The State University of New York

  • Andreas Russ

    • SUNY Buffalo
    • University at Buffalo, The State University of New York

  • Athos Petrou

    • University at Buffalo, The State University of New York
    • SUNY Buffalo

  • H. Luo

    • University at Buffalo, The State University of New York

  • George Kioseoglou

    • University of Crete