Depending on its specific structure, or so-called chirality, a single-walled carbon nanotube (SWCNT) can be either a conductor or a semiconductor. This feature ensures great potential for building ∼1 nm sized electronics if chirality-selected SWCNTs could be achieved. However, due to the limited understanding of the growth mechanism of SWCNTs, reliable methods for chirality-selected SWCNTs are still pending. Here we present a theoretical model on the chirality assignment and control of SWCNTs during the catalytic growth. This study reveals that the chirality of a SWCNT is determined by the kinetic incorporation of pentagons, especially the last (6^th) one, during the nucleation stage. Our analysis showed that the chirality of a SWCNT is randomly assigned on a liquid or liquid-like catalyst surface, and two routes of synthesizing chirality-selected SWCNTs, which are verified by recent experimental achievements, are demonstrated. They are (i) by using high melting point crystalline catalysts, such as Ta, W, Re, Os, or their alloys, and (ii) by frequently changing the chirality of SWCNTs during their growth. This study paves the way for achieving chirality-selective SWCNT growth for high performance SWCNT based electronics.

中文翻译：

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催化单壁碳纳米管生长过程中的手性分配动力学及通向选择性生长的途径†

取决于其特定结构或所谓的手性，单壁碳纳米管（SWCNT）可以是导体，也可以是半导体。如果可以实现手性选择的SWCNT，则此功能可确保构建约1 nm尺寸的电子产品的巨大潜力。然而，由于对SWCNT的生长机理的了解有限，用于手性选择的SWCNT的可靠方法仍在等待中。在这里，我们提出了催化生长过程中SWCNTs的手性分配和控制的理论模型。这项研究表明，一个SWCNT的手性由五边形的动力学结合，尤其是最后（6确定^第）一，在成核阶段。我们的分析表明，SWCNT的手性是随机分配在液体或类似液体的催化剂表面上，并证明了合成手性选择的SWCNT的两种途径，这些途径已被最近的实验成果证实。它们是（i）通过使用高熔点晶体催化剂（例如Ta，W，Re，Os或其合金），以及（ii）在其生长过程中经常改变SWCNT的手性。这项研究为高性能SWCNT基电子产品实现手性选择性SWCNT增长铺平了道路。