AVS 62nd International Symposium & Exhibition
    Electronic Materials and Processing Thursday Sessions
       Session EM+MS-ThM

Paper EM+MS-ThM2
Infrared Nanoscopy of Indium-rich InGaN Epilayers

Thursday, October 22, 2015, 8:20 am, Room 210E

Session: III-N Nitrides for Optoelectronic Applications
Presenter: Yohannes Abate, Georgia State University
Authors: Y. Abate, Georgia State University
D. Seidlitz, Georgia State University
N. Dietz, Georgia State University
I. Ferguson, Missouri University of Science and Technology
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The unique optical and electrical properties of ternary In1-xGaxN epilayers and heterostructures therewith makes this material system attractive for various optoelectronic device applications, including but not limited to high-speed electronics, frequency agile photovoltaic solar cells, or light emitting devices. However, the presently utilized growth methods enable the indium incorporation in In1-xGaxN heterostructures to a narrow composition range, before phase instabilities are encountered. As a potential pathway to extend the stable composition range and the control of point defects in the alloys, we explored in recent years the reactor pressure dependency under superatmospheric MOCVD - also denoted high-pressure chemical vapor deposition (HPCVD) - conditions. In this contribution we will report and discuss on the growth of indium-rich ternary In1-xGaxN epilayers and the influence of the pulse separations on the phase purity and stability of indium-rich In1-xGaxN epilayer and resulting structural and optical properties. The InGaN epilayers have been characterized by x-ray diffraction, Raman spectroscopy, atomic force microscopy, and by several optical techniques such as infrared (IR) reflectance and optical absorption spectroscopy. The free carrier concentrations have been estimated by analyzing the IR-reflectance spectra and by Raman A1(LO) mode line shape analysis.