Research on Optoelectronic Mechanisms for Semiconductor Lasers Based on GaN, Ga(x)In(1-x)N and Al(x)-Ga(1-x)N Epitaxial Layers
Abstract
The goal of this research is to understand and measure parameters that determine threshold currents and quantum efficiencies of injection lasers based on the group-III nitride solid solutions. Standards for SIMS analysis for the common impurities in the group-III nitrides were established in collaboration with Evans East. Impurity and solid solution profiles for commercial LEDs and experimental semiconductor lasers were made. The energy gap of GaN at 300 K was established as 3.452 eV. The absorption coefficient, alpha, and the ordinary refractive index, n(o), were obtained from optical transmission measurements of p-type Al(x)Ga(1-)N doped with Mg. The dispersion of the ordinary and extraordinary refractive indices of Al(x)Ga(1-x)N were determined by a prism coupling technique. An algorithm was developed to permit optical field calculations for waveguiding. These calculations demonstrated that layers outside the SCH waveguide strongly affect the optical field for thin cladding layer thicknesses and result in resonant coupling of light out of the waveguide and increase the laser threshold. The electron capture time in In(x)Ga(1-x)N multiple quantum wells was measured to be 310-540 fs.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 10, 2000
- Accession Number
- ADA378891
Entities
People
- H. C. Casey Jr.
Organizations
- Duke University