Abstract
Uniform nanowires were grown over a selected area of a TiO 2 /sapphire substrate using a horizontal furnace system with a radio frequency (RF) heater. The growth of the nanowire was governed by a catalyst-free vapour-solid (VS) mechanism. The x-ray diffraction pattern showed that the nanowires comprised TiO 2 in the pure rutile phase. The size of the TiO 2 nanowires was verified using field emission scanning electron microscopy (FESEM), which showed that the diameters were in the range 50-100 nm and the lengths were in the range 1-2 νm. The nanowire growth direction and its crystalline structure were examined using high-resolution transmission electron microscopy (HRTEM), indicating that these nanowires had a single-crystalline structure and grew along the [110] axis. A blue emission peak at ∼380 nm was obtained under examination by photoluminescence (PL), which revealed only single-crystalline rutile TiO 2 nanowires, and thus indicated that the single-crystalline TiO 2 nanowire could be a candidate for use in optoelectronic devices.