Ion beam irradiation and annealing effects on carbon nanotube dispersed polyimide thin films

Carbon nanotube (CNT) dispersed polyimide films were prepared using an ultrasonic homogenizer and a spin coater. Ion irradiation followed by thermal annealing was performed in order to enhance the conductivity of the films. The samples were irradiated at room temperature with 20 keV nitrogen ions at fluences ranging from 1013 to 1016 cm− 2 and then annealed at 673 K for 10 min in vacuum. The resistance of the irradiated samples was increased for all the irradiation doses. However, after annealing, the resistance decreased in the cases of irradiation at fluences of 1015 and 1016 cm− 2. In the case of the sample irradiated at 1015 cm− 2 particularly, the resistance after annealing was lower than that of the unirradiated sample. The effect of carbonization of the polyimide, as a result of the irradiation, and the recovery of defects by annealing, contributed to conductivity enhancement.