*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
Title: III-Nitride Homojunction Tunnel Junctions and Nitrogen Plasma Considerations for High Growth Rate Plasma-Assisted Molecular Beam Epitaxy
Committee:
Dr. Doolittle, Advisor
Dr. Frazier, Chair
Dr. Yoder
Abstract:
The objective of the proposed research is to improve the growth and fabrication of group-III nitride materials and devices via plasma-assisted molecular beam epitaxy. The III-nitride material system is explored due to its tunable direct bandgap from 0.7-6.2 eV, spanning from the infrared to deep ultraviolet wavelengths. Current state-of-the-art optoelectronic III-nitride devices are mainly composed of GaN and are thus most efficient in the blue visible wavelength regime. Materials relevant for the longer and shorter wavelengths remain immature due to a variety of growth related issues such as phase separation, decomposition, and insufficient p-type doping. Shorter wavelength devices in the ultraviolet range show promise in applications such as water and air purification and sterilization. Longer wavelength devices in the visible and infrared range are promising for high temperature concentrator solar cells and more efficient red and green light emitting diodes. Heavily doped GaN tunnel junctions are discussed and AlGaN tunnel junctions are proposed to improve current and next generation shorter wavelength device performances via improved contact resistances, current spreading, and the ability to series connect devices. Additionally, plasma considerations to form longer wavelength devices from high indium bearing III-nitrides via plasma-assisted molecular beam epitaxy technique are studied and optimized.
