New Kinds of Quantum Wells
Abstract
The research concentrated almost exclusively on the InAs/A1SB quantum well system, with some supporting work on the GaSb/A1Sb system. Many advances were made. The overall quality of the quantum wells improved, now routinely yielding room-temperature mobilities of 30,000cm2/Vs for 15nm wide wells. A new two-donor model explains the electron concentrations, in terms of a deep EL2- like bulk donor and a mysterious interface donor near the bottom of the well, below the lowest quantum state. A first systematic study of transport properties vs. well widths was undertaken, showing a steep drop in mobility for well widths below 10nm. Cyclotron resonance data taken at the University of Munich give quantitative evidence of non-parabolicity under the combined effect of quantization and band filling. Field effect transistors and photoluminescence data continue to present difficulties. Tilted superlattices (TSLs) from the GaSb/A1Sb system were demonstrated, with very promising properties, as were InAs quantum wells that incorporate GaSb/A1Sb TSLs either as corrugated barriers or as periodic center loading. A record electron mobility for InAs (613,000sq.cm/ Vs) was obtained in the corrugated barrier well.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 27, 1990
- Accession Number
- ADA230346
Entities
People
- Herbert Kroemer
Organizations
- University of California, Santa Barbara