Reinterpretation of single-wall carbon nanotubes: helical structure and electronic properties

Abstract

Reinterpretation of single-wall carbon nanotubes: helical structure and electronic properties Jae-Kap Lee Center for Opto-electronic Materials and Devices, Korea Institute of Science and Technology (KIST), Seoul 02792, South Korea Single-wall carbon nanotubes (SWNTs) have raised considerable interests globally since their first reports in 1993 [1], due to their superior physical properties and unique nanostructure. The prominent performances of CNTs bombarded with numerous papers was enough to expect that they would be novel essential materials in diverse fields including electronics, energy as well as composite materials. However, their applications are still limited although there have been numerous studies for last decades. In this talk, I will reinterpret the structure of SWNTs to be a graphene helix, based on based on my 10 years of study including high-resolution transmission electron microscope (HRTEM) observation, energy calculation [2], simulations of Raman and electronic properties as well as Raman measurements [3]. I will explain some misinterpreted features of SWNTs, their underestimated diameters of 0.8~1.5 nm (which is ~2 nm by HRTEM observation) and semiconducting property reported (SWNTs are intrinsically metallic), which may explain the reasons of the delay or failure of their applications. Finally, I will also discuss the structure of multi-wall CNTs which is of AA’ graphite helix [4,5], as well as ways of utilizing the one dimensional materials and their potential applications. References 1. Iijima, S., Helical microtubules of graphitic carbon, Nature 354, 56 (1991). 2. J.-K. Lee et al., Structure of single-wall carbon nanotubes: A graphene helix, Small 10, 3283 (2014). 3. Park et al., Reinterpretation of single-wall carbon nanotubes by Raman spectroscopy, J. Phys. Chem. C. DOI: 10.1021/acs.jpcc.9b02174 (2019). 4. J.-K. Lee et al., Structure of multi-wall carbon nanotubes