Simulation, Design, and Fabrication of Deep UV Aluminum Gallium Nitride Distributed Bragg Reflectors
The AlGaN materials system has been widely explored for its applications in wide-bandgap optoelectronics active in the UV-C spectrum between 300 - 200 nm. However, serious challenges to its use exist, including a lack of high reflectivity mirror components. Distributed Bragg Reflectors (DBRs) offer some of the most efficient mirrors available in this range. These one dimensional photonic crystals can be grown epitaxially on existing deep UV optical devices within the same growth chamber, making them easy to integrate with existing designs to potentially improve light extraction efficiency. Serious challenges still exist with the use of AlGaN DBRs, including the low contrast of the material system and difficulty of consistent crystal growth. The design of AlGaN DBRs is approached from initial principles based on the optical simulation of these DBRs using the 1D transfer matrix method combined with existing models of the optical parameters of AlGaN films. Exotic approaches such as porous films are also included in the models to expand the range of design parameters. Design rules of thumb based on analysis of these simulations are used to simplify design choices into a systematic approach. Finally, the growth of AlGaN DBRs using molecular beam epitaxy (MBE) and optical and structural characterization methods are introduced.
Molecular Beam Epitaxy; Aluminum Gallium Nitride; Deep UV; Distributed Bragg Reflector; Transfer Matrix Method; Materials Science
Materials Science and Engineering
M.S., Materials Science and Engineering
Master of Science
dissertation or thesis