Phys. Rev. B 73, 115308 (2006) [6 pages]Phonon-assisted recombination in Fe-based spin LEDsReceived 21 October 2005; revised 4 January 2006; published 6 March 2006 The electroluminescence (EL) spectra from Fe∕AlGaAs(n)∕GaAs∕AlGaAs(p) spin LEDs contain an e1h1 excitonic feature; in addition, they exhibit new features not present in the photoluminescence (PL) spectra, that are “satellites” or “replicas” of the exciton. These satellites are red shifted with respect to e1h1 by energies that are approximately equal to those of zone edge phonons in GaAs. The intensity of the replicas depends strongly on bias voltage. In the presence of a magnetic field the satellites become circularly polarized as σ+ but their polarization is always lower than that of e1h1. The satellites are interpreted as due to recombination processes that involve zone edge electrons that tunnel into the GaAs quantum well. These processes occur simultaneously with the emission of zone-edge phonons. Our interpretation is supported by a numerical simulation of the properties of electrons tunneling through an Fe∕GaAs(n) Schottky barrier. © 2006 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevB.73.115308
DOI:
10.1103/PhysRevB.73.115308
PACS:
78.60.Fi, 72.25.Hg, 72.10.Bg, 63.20.Dj
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