Well-Aligned Single-Crystalline GaN Nanocolumns and Their Field Emission Properties

Well-aligned GaN nanocolumns on silicon substrate were fabricated by simple and low-cost chemical vapor deposition without any catalyst. The structure and morphology of the as-synthesized GaN nanocolumns were characterized by X-ray diffraction and scanning and transmission electron microscopies. The aligned GaN nanocolumn arrays exhibited excellent field emission properties with a low turn-on field of 2.6 V/mu m (0.01 ma/cm(2)) and high stability at room temperature, which is sufficient for applications of field emission displays and vacuum nanoelectronic devices. The room-temperature photoluminescence emission with a strong peak at 369 nm indicates that the well-aligned GaN nanocolumns have potential application in light-emitting nanodevices.