講演情報
[17a-P01-8]Growth and Characterization of GaN Nanowires for Photoelectrochemical Water Splitting
Simone Restelli1, Pierre-Marie Coulon2, Blandine Alloing2, 〇Vittorio Bellani1 (1.Unipv, 2.CRHEA)
キーワード：
Nanowires、Water Splitting、Hydrogen production
This study explores the use of Gallium Nitride (GaN) nanowires (NWs) for photoelectrochemical (PEC) water splitting, a promising approach for hydrogen production using solar energy. GaN's wide bandgap makes it suitable for water splitting, but growth challenges, such as high defect densities, hinder its efficiency. Nanowire structures offer a solution due to their low defect density and efficient strain relaxation. We grew high-quality GaN NWs using Metalorganic Vapor-Phase Epitaxy (MOVPE) and characterized them via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Results showed well-ordered hexagonal nanowires with detailed edge resolution (Fig. 1a). Discrepancies between SEM and AFM images were attributed to the convolution between the tip and sample responses given a 12 μm nanowires height compared to a 10 μm maximum tip excursion of our AFM as well as to the presence of a stabilizing medium. Enhanced imaging of scratched regions improved the resolution of the NWs' hexagonal bases (Fig. 1b). The one-dimensional geometry of GaN NWs enhances light absorption efficiency, and their high surface-to-volume ratio improves detection sensitivity and response times, making them ideal for PEC water splitting. Ongoing investigations using Kelvin Probe Force Microscopy, Scanning Tunneling Microscopy and, as a future perspective, Electron Paramagnetic Resonance, aim to improve the engineering of the growth processes and deepen the understanding of the functional responses of GaN NWs, governed by their charge carriers. These findings are crucial for advancing next-generation PEC water splitting devices and highlight the significant potential of GaN nanowires in innovative water splitting technologies.