Hicks Diode Properties of Nanotube Networks

Making semiconductor devices based on single-walled carbon nanotubes (SWCNT) is one of the more compelling potential applications of these long but ultrathin structures. We see asymmetric voltage-current behavior across a random network of SWCNTs contacted by asymmetric metal electrodes (Au/Al). No effort was made to align the SWCNTs or to eliminate metallic nanotubes in our devices, procedures which are common in other devices [1]. Current rectification was, nonetheless, observed in the source-drain bias range of -3V to +3V. Rectification was somewhat surprising since, although metallic tubes are in the minority (~ 1/3), they could potentially act as shunts and mask the electric properties of the semiconducting majority. No correlation between electrode spacing and current rectification was observed. The lowest leakage current measured was 1% of the maximum current carrying capacity. Maximum forward-biased current capacities range between 8μA and 841μA.