(Invited) Comprehensive Analysis of Electronic Properties of Carbon Nanotube Fibers

Abstract

The electronic properties of various carbon nanotube (CNT) fibers that were produced by dry spinning from multi-walled CNT (MWCNT) forests, direct spinning from a CVD furnace and wet spinning of CNTs, are systematically investigated. The electrical conductivity of the fibers is significantly correlated with the effective CNT length [1], yarn density, and CNT alignment in the yarns. In contrast, the tensile strength depends more on the yarn density and the CNT alignment. The temperature dependence of the electronical properties of the CNT fibers are also investigated. Even though the constituent CNTs are very similar, the CNT fibers produced by the wet spinning of the acid treated CNT dispersion and the micelle CNT solution show different temperature dependences in the lower temperature region. The difference can be explained by the different conduction paths in the two wet-spinning fibers. Further, the iodide doping effect on the electronic property of the wet-spinning fiber produced by the acid treated dispersion is also discussed. This work was supported by a project (JPNP16010) commissioned by the New Energy and Industrial Technology Development Organization (NEDO).[1] T. Morimoto et al., ACS Nano, 8, 9897–9904 (2014).