Growth of Horizontal Semiconducting SWNT Arrays with Density Higher than 100 tubes/μm using Ethanol/Methane Chemical Vapor Deposition

• Published in: Journal of the American Chemical Society 2016-06, Vol.138 (21), p.6727-6730
• Main Authors: Kang, Lixing, Zhang, Shuchen, Li, Qingwen, Zhang, Jin
• Format: Article
• Language: English
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.6b03527

Horizontally aligned semiconducting single-walled carbon nanotube (s-SWNT) arrays with a certain density are highly desirable for future electronic devices. However, obtaining s-SWNT arrays with simultaneously high purity and high density is extremely challenging. We report herein a rational approach, using ethanol/methane chemical vapor deposition, to grow SWNT arrays with a s-SWNT ratio over 91% and a density higher than 100 tubes/μm. In this approach, at a certain temperature, ethanol was fully thermally decomposed to feed carbon atoms for Trojan-Mo catalysts growing high density SWNT arrays, while the incomplete pyrolysis of methane provided appropriate active H radicals with the help of catalytic sapphire surface to inhibit metallic SWNT (m-SWNT) growth. The synergistic effect of ethanol/methane mixtures resulted in enriched semiconducting SWNTs and no obvious decrease in nanotube density due to their milder reactivity and higher controllability at suitable growth conditions. This work represents a step forward in large-area synthesis of high density s-SWNT arrays on substrates and demonstrates potential applications in scalable carbon nanotube electronics.