Chirality Distributions for Semiconducting Single-Walled Carbon Nanotubes Determined by Photoluminescence Spectroscopy

To realize single-walled carbon nanotube (SWCNT) chiral selective growth, elucidating the mechanism of SWCNT chirality (n,m) selectivity is important. For this purpose, an accurate evaluation method for evaluating the chirality distribution of grown SWCNTs without post-growth processing or liquid-dispersion of SWCNTs is indispensable. Here, we used photoluminescence spectroscopy to directly measure the chirality distributions of individual semiconducting SWCNTs suspended on a pillar-patterned substrate. The number of chirality-assigned SWCNTs was up to 332 and 17 chirality types with the chiral angles ranging from 0 degrees to 28.05 degrees were detected. The growth yield of SWCNTs was confirmed to primarily depends on the chiral angle in accordance with the screw dislocation model. Furthermore, when higher-yield chiralities are selected, the chiral angle distribution with a peak corresponding to near-armchair SWCNTs is well fitted with a model that incorporates the thermodynamic effect at the SWCNT-catalyst interface into the kink growth-based kinetic model. Our quantitative and statistical data provide new insights into SWCNT growth mechanism as well as experimental confirmation of theoretical predictions.

Automated summary

The study used photoluminescence spectroscopy to directly measure the chirality distributions of individual semiconducting SWCNTs, confirming the influence of chiral angles on the growth yield. When higher-yield chiralities are selected, the chiral angle distribution fits well with a model that incorporates the thermodynamic effect. These quantitative and statistical data provide new insights into the SWCNT growth mechanism and validate theoretical predictions.