2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/143548Charge transport in semiconducting single-walled nanotubes (SWNTs) with Schottky-barrier contacts has been studied at high bias. We observe nearly symmetric ambipolar transport with electron and hole currents significantly exceeding 25 micron-ampere, the reported current limit in metallic SWNTs due to optical phonon emission. Four simple models for the field-dependent velocity (ballistic, current saturation, velocity saturation, and constant mobility) are studied in the unipolar regime; the high-bias behavior is best explained by a velocity saturation model with a saturation velocity of 2 x 10^7 cm/s.to appear in Phys. Rev. LettMaterials ScienceMesoscale and Nanoscale Physicstext