Sequential Resonant Tunneling and Electric Field Effects in Semiconductor Superlattices.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 12, 1997
- Accession Number
- ADA328310
Entities
People
- Roberto Merlin
Organizations
- University of Michigan