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Structural control of single-wall carbon nanotubes (SWCNTs) with uniform properties is critical not only for their property modulation and functional design but also for applications in electronics, optics, and optoelectronics. To achieve this goal, various separation techniques have been developed in the past 20 years through which separation of high-purity semiconducting/metallic SWCNTs, single-chirality species, and even their enantiomers have been achieved. This progress has promoted the property modulation of SWCNTs and the development of SWCNT-based optoelectronic devices. Here, the recent advances in the structure separation of SWCNTs are reviewed, from metallic/semiconducting SWCNTs, to single-chirality species, and to enantiomers by several typical separation techniques and the application of the corresponding sorted SWCNTs. Based on the separation procedure, efficiency, and scalability, as well as, the separable SWCNT species, purity, and quantity, the advantages and disadvantages of various separation techniques are compared. Combined with the requirements of SWCNT application, the challenges, prospects, and development direction of structure separation are further discussed. [ABSTRACT FROM AUTHOR]

The intersubband plasmons (ISBPs) of single‐wall carbon nanotubes (SWCNTs) endow SWCNT‐based optoelectronic devices with more functions. However, the structural dependence of the ISBPs of SWCNTs is not fully understood. Here, the effect of electronic types and diameters of SWCNTs on the energy and intensity of their ISBPs is investigated systematically. The results show that the ISBP energy of semiconducting SWCNTs is ≈50–250 meV larger than that of metallic SWCNTs with the same diameters, while the ISBP integral intensity is approximately 1.25 to 4 times stronger. Diameter dependence of ISBPs for both semiconducting and metallic SWCNTs is also observed. With a decrease in diameter, the ISBPs shift to higher energies, while the intensity decreases dramatically. When the diameter is reduced to less than 1 nm, the ISBPs become unobservable. Interestingly, the energy separation between the ISBPs and interband transition S22 (M11) decreases with an increase in diameter. Theoretical calculations show that the structure‐dependent ISBP characteristics are dominated by the electronic states of SWCNTs. Based on the ISBP characteristics of different SWCNTs, high‐performance SWCNT‐based near‐infrared electrochromic devices are fabricated by mixing small‐diameter metallic SWCNTs with semiconducting SWCNTs due to their high conductivity and negligible ISBP signals. [ABSTRACT FROM AUTHOR]