Ultra-High Yield Growth of Vertical Single-Walled Carbon Nanotubes: Hidden Roles of Hydrogen and Oxygen

TL;DR

This paper introduces an oxygen-assisted CVD method that significantly enhances the growth yield of vertical single-walled carbon nanotubes by controlling hydrogen and oxygen roles, enabling substrate-independent fabrication.

Contribution

It reveals the roles of hydrogen and oxygen in SWNT growth and develops a universal, substrate-independent method for high-yield vertical SWNT fabrication.

Findings

Oxygen scavenges damaging hydrogen species during growth.

Optimized C/H ratio improves SWNT yield.

Method enables growth on any substrate.

Abstract

An oxygen assisted hydrocarbon chemical vapor deposition (CVD) method is developed to afford large-scale highly reproducible ultra high-yield growth of vertical single-walled carbon nanotubes (SWNT). It is revealed that reactive hydrogen (H)-species, inevitable in hydrocarbon-based growth, are damaging to the formation of sp2-like SWNTs. The addition of oxygen scavenges H-species and provides a powerful control over the C/H ratio to favor SWNT growth. The revelation of the roles played by hydrogen and oxygen leads to a unified and universal optimum growth condition for SWNTs. Further, a versatile method is developed to form vertical SWNT films on any substrate, lifting a major substrate-type limitation for aligned SWNTs.