Facile synthesis of carbon nanotubes and their use in the fabrication of resistive switching memory devices

An electrophoretic deposition technique was performed to prepare metal catalysts (Fe and Ni) over stainless steel substrates. The catalytic activity of the as prepared metal catalysts was evaluated for the growth of carbon nanotubes (CNTs) by chemical vapour deposition. The well graphitized CNTs obtained from the Fe catalyst were utilized for the fabrication of a metal-insulator-metal (MIM) type memory device. The effect of the CNT content on the electrical bistable switching of a polyvinyl alcohol (PVA)-CNT composite film was investigated. By varying the CNT content in the PVA films, the Si/Al/PVA-CNT/Al memory device performance parameters, such as conductivity, turn-on voltage and ON/OFF state current ratio could be tuned accordingly. The device exhibited the characteristic behavior of an insulator, write-once-read-many-times, rewritable and conductor effect by doping various weight percentages of CNT in PVA. The device with 3% CNT in PVA demonstrated a significantly low turn-on voltage of -1 V and a high ON/OFF state current ratio of 10(7). We thus suggest that solution processed PVA-CNT films are economical and a potential candidate for memory devices.