High bias transport in single-wall carbon nanotubes

We study transport and scanning probe properties on single-wall nanotube (SWNT) devices at high voltage bias. Measurements of contact resistance indicate that cur-rent saturation at high bias is an intrinsic property of SWNTs. We use a combination of scanning probe and transport techniques to measure a voltage drop along a nanotube at high bias. Together, these two observations provide experimental confirmation of the phonon-emission model of current saturation, Surprisingly, some SWNT devices show roll-off to finite resistance at high bias, instead of current saturation. We analyze these devices by including electron-phonon coupling in the phonon-emission model and use this modification to extract the value for the associated scattering length, 1(ph)=45nm.