Voltage

Engineering

Materials science

Semiconductor

Substrate (aquarium)

Geology

Oceanography

Transistor

Nanotechnology

Carbon nanotube

Nanoelectronics

Wafer

Electronics

Field-effect transistor

Liquid crystal

Nanotube

Carbon nanotube field-effect transistor

Optoelectronics

Electrical engineering

Science Advances

Semiconducting carbon nanotubes promise faster performance and lower power consumption than Si in field-effect transistors (FETs) if they can be aligned in dense arrays. Here, we demonstrate that nanotubes collected at a liquid/liquid interface self-organize to form two-dimensional (2D) nematic liquid crystals that globally align with flow. The 2D liquid crystals are transferred onto substrates in a continuous process generating dense arrays of nanotubes aligned within ±6°, ideal for electronics. Nanotube ordering improves with increasing concentration and decreasing temperature due to the underlying liquid crystal phenomena. The excellent alignment and uniformity of the transferred assemblies enable FETs with exceptional on-state current density averaging 520 μA μm−1at only −0.6 V, and variation of only 19%. FETs with ion gel top gates demonstrate subthreshold swing as low as 60 mV decade−1. Deposition across a 10-cm substrate is achieved, evidencing the promise of 2D nanotube liquid crystals for commercial semiconductor electronics.

Aligned 2D carbon nanotube liquid crystals for wafer-scale electronics