Self-Assembly of Semiconducting Single-Walled Carbon Nanotubes into Dense, Aligned Rafts

TL;DR

This paper demonstrates the self-assembly of highly pure semiconducting single-walled carbon nanotubes into dense, aligned rafts, enabling the fabrication of high-performance nanoelectronic devices with unprecedented on-current and density.

Contribution

It introduces a method for separating and self-assembling semiconducting SWNTs into dense, aligned structures suitable for nanoelectronics.

Findings

Achieved high packing density (~100 tubes/μm) in SWNT rafts.

Fabricated short-channel FETs with high on-currents (~120 μA).

Demonstrated dense alignment improves device performance.

Abstract

Single-walled carbon nanotubes are promising nanoelectronic materials but face long-standing challenges including production of pure semiconducting SWNTs and integration into ordered structures. Here, highly pure semiconducting single-walled carbon nanotubes are separated from bulk materials and self-assembled into densely aligned rafts driven by depletion attraction forces. Microscopy and spectroscopy revealed a high degree of alignment and a high packing density of ~100 tubes/micron within SWNT rafts. Field-effect transistors made from aligned SWNT rafts afforded short channel (~150 nm long) devices comprised of tens of purely semiconducting SWNTs derived from chemical separation within a < 1 micron channel width, achieving unprecedented high on-currents (up to ~120 microamperes per device) with high on/off ratios. The average on-current was ~ 3-4 microamperes per tube. The results demonstrated densely aligned high quality semiconducting SWNTs for integration into high performance nanoelectronics.