Date of Award
Summer 8-23-2010
Degree Type
Thesis
Degree Name
Master of Science (MS)
Department
Physics and Astronomy
First Advisor
Dr. Nikolaus Dietz
Second Advisor
Dr. Unil A. G. Perera
Third Advisor
Dr. Unil A. G. Perera
Fourth Advisor
Dr. Vadym Apalkov
Abstract
Optical absorption spectroscopy has been applied to study properties such as the fundamental absorption edge and defect absorption centers of group III-nitride compound semiconductor epilayers. The investigation in this thesis focused on analyzing the band gap of indium-rich In1-xGaxN epilayers, which where grown by the high-pressure chemical vapor deposition (HPCVD) technique. Our results - together with literature data for gallium-rich In1-xGaxN alloys indicate that the shift of the fundamental band gap of In1-xGaxN with composition x can be described with a bowing parameter of b = 2.2eV. Temperature dependent transmission measurements show that the band gap variation with temperature follows a S-shape behavior for small gallium concentration and shifts towards a Varshni type behavior for a higher gallium concentrations. The S-shape behavior is attributed to nanoscale compositional fluctuations/clustering in the ternary alloy system. The thicknesses of the measured In1-xGaxN epilayers have been analyzed through multilayer stack model calculations of the transmission spectra. The free electron concentration in the In1-xGaxN epilayers has been obtained from simulations of infrared reflectance spectra.
DOI
https://doi.org/10.57709/1469393
Recommended Citation
Wang, Jielei Ms, "Optical Properties of In1-xGaxN Epilayers Grown by HPCVD." Thesis, Georgia State University, 2010.
doi: https://doi.org/10.57709/1469393