Committee: 

Dr. Dupuis, Advisor     

Dr. Shen, Chair

Dr. Yoder

Abstract: The objective of the proposed research is to develop high-performance III-nitride-based ultraviolet (UV) p-i-n avalanche photodiodes (APDs) with high optical gain using metalorganic chemical vapor deposition (MOCVD) system. However, the realization of high-performance UV-APDs has been hampered by high dislocation densities originating from heteroepitaxial layer grown on the lattice-mismatched substrates, resulting in higher dark current density, device size limitation, and device failure by microplasma formation as well as low yield and non-uniformity in an array format. To solve this problem, I proposed material growth on bulk GaN substrates with low dislocation density and sophisticated device fabrication process including low-damage etching and high-quality dielectric passivation. The major aims of the work following: 1) to improve characteristics of Al0.05Ga0.95N p-i-n UV-APDs 2) to demonstrate uniform and reliable GaN p-i-n UV-APD arrays with large detection area.