HV-CVD synthesis yielding B-doped SWCNTs with a constrained diameter distribution.

Single-walled carbon nanotubes (SWCNTs) are among the most fundamental and revolutionary building blocks. Therefore, finding methods to tune their properties is highly desirable. Substitutional doping represents one feasible path toward this goal, in particular, for the semiconductors industry. In this work, it is shown how high-vacuum chemical vapor deposition (HV-CVD) enables the reliable and consistent growth of small-diameter B-doped SWCNTs with a set narrow diameter distribution over a 300 °C temperature window, independent from the composition of various tested catalysts. The synthesis parameters have only a minor influence on the diameter distribution. The method is rather feedstock and pressure dependent. This was explored using a wide range of catalysts, including both single- and multi-metal systems using different supports. These results demonstrate the versatility and robustness of HV-CVD with low-vapour pressure B-containing feedstocks as a path to nanotubes with defined and, with most catalysts, very narrow diameter distribution with minimal post-processing.