Optically pumped transport in ferromagnet-semiconductor Schottky diodes (invited)

A. F. Isakovic, D. M. Carr, J. Strand, B. D. Schultz, C. J. Palmstrom, P. A. Crowell

Research output: Contribution to journalArticlepeer-review

Abstract

Optical pumping is used to generate spin-polarized carriers in epitaxial ferromagnet-GaAs Schottky diodes with In yGa 1-yAs quantum wells placed in the depletion region. A strong dependence of the photocurrent on the polarization state of the incident light is observed, and a series of measurements as a function of excitation energy, bias voltage, magnetic field, and excitation geometry are used to distinguish spin-dependent transport from a variety of background effects. The spin polarization of the photocurrent for pumping energies at and above the band gap of GaAs is of order 0.5% or less. Much larger polarization dependence is observed for excitation energies near the quantum well ground state. Although background effects are very large in this regime, the field dependence of the polarization signal for several samples is suggestive of spin-dependent transport.

Original languageEnglish (US)
Pages (from-to)7261-7266
Number of pages6
JournalJournal of Applied Physics
Volume91
Issue number10 I
DOIs
StatePublished - May 15 2002

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