Excess Low Frequency Noise in Single-Wall Carbon Nanotube

Low frequency noise measurements have been performed on a single-wall carbon nanotube connected by Ti/Au electrodes. It has been found that the 1/f noise decreases when the measurements are undertaken under vacuum and when the nanotube is partially degassed, showing a correlation between the fluctuation inducing the 1/f noise and the presence of gases. We show that the 1/f noise sources are located at the metal/nanotube contacts. When the device is annealed under vacuum at 450K, some Lorentzian shapes are observable and can be related to nanotube defects or to strongly bound molecules.