Arrays of horizontal semiconducting carbon nanotubes grown from non-metal catalysts prepared by a “thermophoresis-anchoring” synergistic strategy

• Published in: Nano today 2025-04, Vol.61, p.102562, Article 102562
• Main Authors: Lin, Sizhe, Ye, Tao, Zhang, Xinyu, Zuo, Hui, Zhu, Linxi, Wang, Xiuxia, Li, Changlong, Yang, Zhi, Du, Ran, Lin, Dewu, Hu, Yue
• Format: Article
• Language: English
• Subjects: High density; Non-metal catalyst; Semiconducting; Single-walled carbon nanotube arrays; Thermophoresis - anchoring
• ISSN: 1748-0132
• DOI: 10.1016/j.nantod.2024.102562

The fabrication of uncontaminated single-walled carbon nanotube (SWNT) horizontal arrays is crucial for the development of carbon-based nanoelectronics. However, chemical vapor deposition (CVD) using transition metal catalysts, one of the main methods for preparing SWNT arrays, leaves a significant amount of metal impurities. Here, we report a synergistic thermophoresis-anchoring strategy to prepare uniformly dispersed and size-controllable non-metal SiOx catalysts for the growth of horizontal SWNT arrays. The pyrolysis of silicon-based precursors generates an abundant supply of SiOx particles, which are deposited bottom-up onto the quartz substrate due to the thermal buoyancy induced by a rapid temperature increase. Meanwhile, Surface reconstruction promoted by mechanical force creates numerous anchoring sites on the quartz substrate. This facilitates the capture of catalysts and suppresses their migration and aggregation, thereby promoting the uniform deposition of small-sized catalysts. Consequently, SWNT arrays with a density of 9 tubes per micron are synthesized using these nonmetal SiOx catalysts. Importantly, Raman spectroscopy and electrical characterization reveal a semiconductor ratio of up to 94 % for the directly grown SWNT arrays, which is attributed to an in situ etching mechanism within the confined space. This work provides a viable way to promote the practical application of next-generation carbon-based nanodevices. [Display omitted] •We design a “thermophoresis-anchoring” approach to prepare non-metal SiOx catalysts on the growth substrate, of which the distribution and size can be efficiently regulated according to requirements.•Our study demonstrates the synthesis of SWNT arrays with a density of 9 tubes per μm as well as a semiconductor ratio of up to 94 %, which is attributed to an in-situ etching mechanism within the confined space. Compared to reported works using non-metal catalysts, our approach results in the highest density and semiconducting ratio.