Acoustic-assisted assembly of an individual monochromatic ultralong carbon nanotube for high on-current transistors.

Great effort has been applied to scientific research on the controllable synthesis of carbon nanotubes (CNTs) with high semiconducting selectivity or high areal density toward the macroscale applications of high-performance carbon-based electronics. However, the key issue of compatibility between these two requirements for CNTs remains a challenge, blocking the expected performance boost of CNT devices. We report an in situ acoustic-assisted assembly of high-density monochromatic CNT tangles (m-CNT-Ts), consisting of one self-entangled CNT with a length of up to 100 mm and consistent chirality. On the basis of a minimum consumed energy model with a Strouhal number of approximately 0.3, the scale could be controlled within the range of 1 × 10 to 3 × 10 μm or even a larger range. Transistors fabricated with one m-CNT-T showed an on/off ratio of 10 to 10 with 4-mA on-state current, which is also the highest on-state current recorded so far for single CNT-based transistors. This acoustic-assisted assembly of chiral-consistent m-CNT-Ts will provide new opportunities for the fabrication of high-performance electronics based on perfect CNTs with high purity and high density.