Optical Studies of the Influence of Microscopic Structure on the Optoelectronic Properties of 6.1 Angstrom-Lattice Constant III-V Superlattices
Abstract
The influence of the microscopic structure (particularly at material interfaces) on the optoelectronic properties of 6.1 Angstrom-lattice constant III-V superlattices is presented. Included are discussions of four research areas: 1) Theoretical studies of binary antimonide superlattices, 2) MBE growth of these superlattices. 3) Structural characterization using X-ray diffraction. and 4) continuous-wave and ultrafast optical characterization. The theoretical effort included spin lifetime calculations for bulk GaAs and InAs as well as for GaAs/AlGaAs and InGaAs/InP quantum wells. A fourteen bulk-band basis was utilized to account for the constituent zinc blende symmetry. The spin lifetimes agree with recent experiments within experimental and theoretical error. The experimental effort, multiple quantum well samples were grown with InAs (7ML)/GaSb (12ML) superlattice quantum wells and AlSb barrier regions. Two different MBE growth procedures were used at the material interfaces: 1). 5-second Sb-soaks and 2) migration- enhanced epitaxy (MEE). Use of MEE was an attempt to realize more abrupt interfaces and reduce the defect concentrations. The structures were characterized using time-resolved photoluminescence and time-resolved differential transmission. Excellent Shockley-Read-Hall lifetimes in the 4-6 ns range were measured. Furthermore, spin lifetime measurements were made on a sample grown using the Sb-soaks as well as on a previous InAs/GaInSb/InAs/InGaAlAsSb 4-layer superlattice sample.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 2000
- Accession Number
- ADA373828
Entities
People
- Michael E. Flatté
- Thomas C. Hasenberg
- Thomas F. Boggess
Organizations
- University of Iowa