Magneto-transport in Type-Enriched Single-Wall Carbon Nanotube Networks

Single-wall carbon nanotubes (SWCNTs) exhibit a wide range of chirality-dependent physical phenomena. This dependency complicates in-depth understanding of ensemble behavior, since nanotube networks contain numerous chiralities. In particular, electronic-type mixing greatly hinders the development of a comprehensive picture of SWCNT ensemble electrical transport. Here, we systematically study temperature-dependent magnetoconductivity (MC) in semiconductor and metal SWCNTs. In the semiconductor-enriched network, we observe 2D variable-range hopping conduction from 5 to 290 K. Low-temperature MC reveals a large, negative MC from which we determine the wavefunction localization length and Fermi energy density of states. In contrast, the metal-enriched film shows positive MC that increases with decreasing temperature, a behavior we attribute to 2D weak localization. Using this model, we determine carrier phase coherence and describe the temperature-dependent conductivity. These extensive transport measurements on type-enriched SWCNTs provide insights, which pave the way for nanotube solid-state devices.