I-V characteristics of multi-walled carbon nanotubes synthesised using ECR-CVD

Abstract

Multi-walled carbon nanotubes (MWCNTs) are synthesised at a temperature of 650°C and 700°C by electron cyclotron resonance plasma chemical vapour deposition (ECR-CVD). These MWCNTs have been grown on Si substrate using a thin film of Fe as a catalyst, which is coated by RF-sputtering. Acetylene is used as a source of carbon and plasma was created by argon gas. Ammonia is used to etch away amorphous carbon produced by plasma exposure. From the SEM image, it was observed that the length and diameter of MWCNTs varies from 70 nm to 150 nm and 35 nm to 40 nm respectively. The I-V characteristics have been performed by two-probe method under a vacuum of 10−3 torr at room temperature. On the basis of I-V characteristics, it is concluded that these CNTs show the semiconducting behaviour at all the temperatures.