Blue-Green Laser Diode Research Program.
Abstract
A total of 24 heteroepitaxial films of ZnSe on GaAs were grown in the St. Paul laboratory during the reporting period. A range of ratios of the Zn beam pressure to the Se beam pressure during growth (the BPR), and a range of substrate temperatures during growth, were investigated in order to determine the set of growth conditions giving the best intrinsic films. The term best is defined as the largest near-band-edge emission observed in photoluminescence, combined with the highest peak mobility, lowest room temperature carrier density, and lowest total concentration of ionized impurities. While the series of films has not yet been completed, it appears that a BPR of 1:1 and a substrate temperature of 350 c give the best intrinsic films. Preliminary evidence suggests that the surface quality of the films begins to degrade after exposure to room ambient for about two weeks. The six-month report for this project described the first attempts to grow ZnSe epitaxially on Ge substrates. This work has been expanded to include an epitaxial buffer layer of Ge between the ZnSe layer and the Ge substrate. This was done to provide a smoother substrate for the ZnSe growth. RHEED patterns indicate that ZnSe films grown on the Ge buffer layer are indeed smoother on the atomic scale. Photoluminescence results show that the near-band-edge emission is much stronger than for films without a buffer layer.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1986
- Accession Number
- ADA173306
Entities
Organizations
- 3M