Review on fabrication and applications of GaN nanorods

Gallium nitride (GaN) nanorods offer multiple advantages over planar GaN materials, including high specific surface area, high quantum efficiency, and excellent optoelectronic performance. They have been widely applied in light-emitting devices, photodetectors, full-spectrum light sources, laser emitters. In recent years, researchers have explored various preparation methods and process conditions to achieve ideal GaN nanorods, including deposition techniques such as hydride vapor phase epitaxy, molecular beam epitaxy, and metal-organic chemical vapor deposition, etching processes such as focused ion beam, inductively coupled plasma-reactive ion etching, as well as post-treatment repair strategies. Studies have shown that each process step significantly affects the morphology and overall performance of GaN nanorods. This article reviews common preparation methods for GaN nanorods, categorizing them into bottom-up and top-down approaches based on fabrication pathways. It first introduces bottom-up methods, including direct growth and template-assisted growth, followed by a discussion of top-down approaches such as direct etching, mask-assisted etching, and subsequent defect-corrosion and annealing repair. The principles, process flows, and key parameters of both fabrication routes are analyzed. Finally, the applications of GaN nanorods in fields such as light-emitting diodes, lasers, photodetectors, and sensors are summarized and evaluated, providing valuable insights for the future development and practical utilization of GaN nanorods.