Origin of hysteresis in gate-modulated transport in single-wall carbon nanotubes

Transfer characteristics of gate-modulated transport in single-wall carbon nanotubes show significant hysteresis. This hysteresis is usually attributed to a screening of the gate voltage due to mobile charges/ions in the presence of a trapping/de-trapping mechanism within the gate architecture. From a temperature dependence of the hysteresis behavior, we suggest an alternate mechanism, where the screening charges are injected from the nanotube itself into the surrounding dielectric. Any trapping/de-trapping mechanism does not appear to play a significant role, and the experimental results can be understood in terms of a capacitive charging of the surrounding dielectric.