Accession Number : ADA328310

Title :   Sequential Resonant Tunneling and Electric Field Effects in Semiconductor Superlattices.

Descriptive Note : Final rept. 11 May 92-31 Dec 96,

Corporate Author : MICHIGAN UNIV ANN ARBOR

Personal Author(s) : Merlin, R.

PDF Url : ADA328310

Report Date : 12 JUN 1997

Pagination or Media Count : 10

Abstract : This report focuses on mechanisms of negative-differential-conductance in weakly-coupled semiconductor superlattices and, in particular, on the phenomenon of sequential resonant tunneling leading to electric-field domains. Our approach involves a combination of various theoretical and experimental methods including time-resolved photoluminescence, Raman scattering and near-field-optical microscopy. A nearly complete understanding of the domain process has emerged. Specifically, a phase diagram has been established and the various parameters which control transport behavior have been identified. In photoexcited and intentionally doped superlattices, static domains dominate at high carrier concentrations while oscillations occur in a narrow density region above the regime of the quantum-confined Stark effect. Doped, although not photoexcited structures exhibit sustained GHz oscillations. The relevance of these findings to Bloch oscillations is discussed.

Descriptors :   *SUPERLATTICES, *ELECTRIC FIELDS, *SEMICONDUCTORS, DENSITY, LIGHT SCATTERING, METHODOLOGY, SCATTERING, QUANTUM WELLS, PHOTOLUMINESCENCE, CHARGE CARRIERS, ATOMS, SEQUENCES, RESONANCE, TRANSPORT, CONCENTRATION(COMPOSITION), QUANTUM ELECTRONICS, TUNNELING, OSCILLATION, STARK EFFECT, RAMAN SPECTRA, PHASE DIAGRAMS, GUNN EFFECT.

Subject Categories : Electricity and Magnetism
      Atomic and Molecular Physics and Spectroscopy
      Quantum Theory and Relativity

Distribution Statement : APPROVED FOR PUBLIC RELEASE