We are exploring the synthesis of III-nitride nanowires and nanorods by both "bottom-up" and "top-down" methods. Our bottom-up approaches use nanoscale metal (Ni) catalyst particles to direct 1D nanowire growth via the vapor-liquid-solid (VLS) mechanism. Our top-down methods involve the selective etching of III-nitride films to create periodic nanorod arrays. For both methods, we use metal organic chemical vapor deposition (MOCVD), which is used in commercial device growth (such as white LEDs) and which allows for doping and the creation of heterostructures with abrupt junctions.
Q. Li, and G. T. Wang, “Improvement in Aligned GaN Nanowire Growth using Submonolayer Ni Catalyst Films,” Applied Physics Letters 93, 043119 (2008). [link]
G. T. Wang, A. A. Talin, D. J. Werder et al., “Highly aligned, template-free growth and characterization of vertical GaN nanowires on sapphire by metal-organic chemical vapour deposition,” Nanotechnology 17(23), 5773-5780 (2006). [link]
Bottom-up growth of aligned GaN nanowires
Multi-walled AlN nanotube
Periodic GaN nanorod array via top-down