Optical Properties of Thermally Intermixed Quantum Wells and Superlattices
Abstract
The optical properties of thermally intermixed GaAs/AlGaAs quantum wells and superlattices are examined using thermal annealing, photoluminescence (PL), time-resolved photoluminescence (TPL), and theoretical models. A computer model to calculate the energy structure of intermixed quantum wells is refined and used with PL and TPL techniques to characterize the properties of thin (1 monolayer (ML) to 8 ML) annealed wells. A model for intermixed superlattices is developed next which predicts the changes in energy dispersion and density of states with annealing time, and is verified using PL and TPL. Selective intermixing techniques using a gallium focused ion beam (FIB), SiNx encapsulation, and patterned GaAs grown at low substrate temperature (LT-GaAs) are then studied. The FIB technique tends to suppress layer interdiffusion in and around the implanted region. The SiNx encapsulation is most promising with an interdiffusion selectivity ratio of more than 4:1. Initial LT-GaAs experiments show a small selectivity between regions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1991
- Accession Number
- ADA243546
Entities
People
- Michael W. Prairie
Organizations
- Air Force Institute of Technology