Rapid, low-temperature synthesis of single-crystalline Co(3)O(4) nanorods on silicon substrates on a large scale.

When heated in a rapid thermal processor at 350 °C in air, cobalt thin (50 nm thick) films were transformed into Co(3)O(4) nanorods in minutes. The nanorods are single-crystalline and are typically several hundred nanometers long and several tens of nanometers in diameter. They exhibited room-temperature photoluminescence in the visible range and good field emission properties, i.e. a low turn-on field of ∼2.8 V µm(-1) and good stability at high emission currents. This study provides a simple but rapid approach that is compatible with microtechnology and is capable of fabricating metal oxide nanorods at low substrate temperatures, on a large scale.