Silicon nanowires and whiskers obtained by arc discharge

Abstract

Crystalline nanostructures such as nanotubes and nanowires have received increasing attention due to potential applications in nanoscale electronic, optical and sensing devices. Silicon nanowires are of practical interest because of their semiconducting properties. In particular, dimension reduction to a nanometer scale gives rise to several advantages in terms of device applications, due to size and quantum confinement effects. Silicon nanowires have been synthesized by different physical and chemical methods. However, the fabrication of silicon nanowires and nanowhiskers depends on some specific properties of Si and is still a challenge. Here we report the synthesis of silicon nanowires and nanowhiskers by DC arc discharge using a graphite cathode and a graphite anode filled with a Si and C powder mixture. The reactor was operated in a pre-evacuated argon-filled chamber at a pressure of 3×104 Pa. The arc current was maintained at 75 A by a DC power supply. No catalysts were used. The synthesis products were grey-white in color. The material obtained was studied by SEM. The structures (nanowires and nanowhiskers) are described and discussed. © 2008 IOP Publishing Ltd.