Synthesis of single crystalline silicon nanowires and investigation of their electron field emission

Abstract

A systematic study of the effects of growth parameters on the morphology and field emission performance of silicon nanowires has been undertaken. Single-crystalline silicon nanowires were synthesized by chemical vapor deposition using indium tin oxide-coated glass as a substrate. Morphologies, internal structures and chemical compositions of the resulting nanowires were analyzed using scanning electron microscopy, transmission electron microscopy and energy-dispersive x-ray spectroscopy. The resulting silicon nanowires possessed a highly ordered single crystalline Si core without an external oxide layer and no obvious indium or tin impurities. For silicon nanowires with growth-times of 5, 10, and 20 mins, the turn-on fields were determined to be 7.4, 7.9, and 11.5V∕μm, while the threshold fields were 9.9, 11.8, and 16.9V∕μm, respectively. Field enhancement factors of 540, 270, and 265 were also calculated while peak emission currents in excess of 25μA were observed for nanowires with 5 min growth-times. These results strongly suggest the viability of silicon nanowires as emitters in devices where high emission currents are required.