Date of Award




Document Type


Degree Name

Doctor of Philosophy (PhD)


Department of Nanoscale Science and Engineering


Nanoscale Engineering

Content Description

1 online resource (xii, 171 pages) : color illustrations.

Dissertation/Thesis Chair

Fatemeh Shahedipour-Sandvik

Committee Members

Alain Diebold, Natalya Tokranova, L. Douglas Bell, Alexey Vert


AlGaN novel growth technique, III-N APD edge termination, III-N APD sidewall passivation, III-N novel photodiode designs, solar-blind avalanche photodiodes (APD), ultraviolet (UV) photodiodes, Avalanche photodiodes, Nitrides, Gallium nitride

Subject Categories

Electrical and Electronics | Materials Science and Engineering | Nanoscience and Nanotechnology


Solar-blind ultraviolet avalanche photodiodes are an enabling technology for applications in the fields of astronomy, communication, missile warning systems, biological agent detection and particle physics research. Avalanche photodiodes (APDs) are capable of detecting low-intensity light with high quantum efficiency and signal-to-noise ratio without the need for external amplification. The properties of III-N materials (GaN and AlGaN) are promising for UV photodetectors that are highly efficient, radiation-hard and capable of visible-blind or solar-blind operation without the need for external filters. However, the realization of reliable and high performance III-N APDs and imaging arrays has several technological challenges. The high price and lack of availability of bulk III-N substrates necessitates the growth of III-Ns on lattice mismatched substrates leading to a high density of dislocations in the material that can cause high leakage currents, noise and premature breakdown in APDs. The etched sidewalls of III-N APDs and high electric fields at contact edges are also detrimental to APD performance and reliability. In this work, novel technologies have been developed and implemented that address the issues of performance and reliability in III-Nitride based APDs.