Cubic III-Nitrides for photonics: Physics, materials, and devices

Light-emitting diodes (LEDs), especially InGaN-based LED devices, have achieved remarkable success in solid-state lighting, contributing to 25 % of energy savings already. However, expected population growth and increasing demand for lighting necessitate a more efficient approach, which can only be realized by solving the issue of the green gap (i.e., the inefficiency of the state-of-the-art green LEDs). Cubic nitride LEDs are proposed as a promising solution to the green gap, due to well-documented advantages in the literature. However, there are theoretical and experimental issues in the current approach that need to be innovated in order to translate these material advantages into functional devices and address the green gap with the cubic nitride approach. In this thesis, the realization of cubic nitride LEDs will be tackled in both theoretical and experimental aspects. First, three crucial design rules specific to cubic nitride LEDs are suggested, enabling highly efficient theoretical stack design. Second, high-quality, phase-pure cubic GaN is demonstrated and characterized as a template for further material growth. Next, purely cubic active layers are synthesized and characterized, showing high enough internal quantum efficiency with green emission to make a functional device. Finally, the LED and micro-LED fabrication based on cubic GaN template are shown, and the characterization of these novel devices is discussed.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Lee, Jaekwon

Contributors dc:contributor

• Bayram, Can
• Dallesasse, John Michael
• Goddard, Lynford L
• Kim, Kyekyoon
• Leburton, Jean-Pierre
• Ploessl, Andreas Eberhard
• Solgaard, Olav

• Cubic Nitride
• Light-emitting diodes
• green gap

Statement dc:rights

• Copyright 2025 Jaekwon Lee

Language dc:language

en, eng

Handle dc:identifier

https://hdl.handle.net/2142/129670

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F129670