677931 event 1729893918 1729894439 <![CDATA[Ph.D. Dissertation Defense - Fatima Zahrae Tijent]]> Title:  H-BN Integration in III-Nitride Devices for Green Hydrogen Applications

Committee:

Dr. Paul Voss, ECE, Chair, Advisor

Dr. Abdallah Ougazzaden (Professor, ECE)

Dr. Jean-Paul Salvestrini (Adjunct Lecturer, ECE)

Dr. Nico F. Declercq (Professor, ME)

Dr. Mustapha Faqir (Professor, Aerospace Engineering)

Dr. El Hachmi Essadiqi (Professor, Aerospace Engineering)

Dr. Hajar Chouiyakh (Professor, Aerospace Engineering)

Dr. Mohamed Balli (Professor)

Dr. Morad El Baz (Professor)

]]> This thesis explores the initial steps in developing an integrated photoelectrochemical (PEC) cell for green hydrogen production using PEC water splitting. The focus is on integrating InGaN (Indium Gallium Nitride), GaN (Gallium Nitride), and h-BN (hexagonal Boron Nitride), which are promising materials for hydrogen production and storage applications thanks to their unique properties. InGaN, for example, offers a tunable band gap, high chemical stability, and good catalytic activity, making it suitable for hydrogen production. However, its efficiency remains low, and production costs are relatively high. To address these challenges, the thesis investigates the integration of h-BN, a two-dimensional material with a layered structure, into InGaN PEC systems. h-BN can reduce production costs by enabling the reuse of growth substrates when used as a release layer. It can also enhance hydrogen production efficiency by reducing the dislocation density when used as an interfacial layer during growth. This research includes first a study of InGaN multiple quantum well photoanodes grown on hBN/sapphire to generate hydrogen via PEC water splitting, revealing the effect of h-BN on surface morphology and charge transfer kinetics. Second, the efficiency of a nanostructured InGaN photoanode in terms of hydrogen production is evaluated through numerical simulations. The most efficient InGaN photoelectrode identified through these studies is selected for a techno-economic analysis to assess the commercial viability of the technology. This analysis evaluates the competitiveness of a fully integrated InGaN nanopyramid photoanode with an h-BN proton exchange membrane (PEM). Additionally, the dual functionality of h-BN is highlighted—not only as a PEM to enhance device lifetime under long-term operational conditions but also as a potential system for hydrogen storage at a microscale level via the formation of h-BN bubbles under UV light irradiation.

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