Hot-wire chemical vapour deposition of carbon nanotubes

Abstract

Owing entirely to their structure, carbon nanotubes (CNTs) possess some of the most remarkable chemical and physical properties. More specifically, they exhibit exceptional strength and toughness, chemical inertness, magnetism, and electrical and thermal conductivity, which have led to them being identified as possible components in a variety of applications such as reinforced composites, nano-scale electronic, electrochemical and power devices. Techniques used to synthesize CNTs include laser ablation of graphite, carbon-arc discharge and chemical vapour deposition (CVD). However, some of these techniques have been shown to be expensive due to high deposition temperatures and are not easily controllable. Recently hot-wire chemical vapour deposition (HWCVD) has been employed for the growth of CNTs at low temperatures [1] as compared to the laser-ablation and arc-discharge techniques with deposition temperatures in excess of 900 ºC. Furthermore, compared to other CVD techniques, the HWCVD system allows for greater control of the growth conditions is more versatile, offer greater CNT yield and can easily be up-scaled to large substrates [1-3]. This paper presents the design of a compact, versatile HWCVD system, constructed at the CSIR, for the growth of CNTs and the study of the deposition parameters influencing the tube structures