Magnetotransport in type-enriched single-wall carbon nanotube networks

X. Wang (1) , W. Gao (1) , Xiaojian Li (1) , Q. Zhang (1) , Sébastien Nanot (2, 1) , E. Haroz (1) , J. Kono (1) , W. D. Rice (1)

1 Electrical and Computer Engineering - Rice University
2 L2C - Laboratoire Charles Coulomb

Single-wall carbon nanotubes (SWCNTs) exhibit a wide range of physical phenomena depending on their chirality. Nanotube networks typically contain a broad mixture of chiralities, which prevents an in-depth understanding of SWCNT ensemble properties. In particular, electronic-type mixing (the simultaneous presence of semiconductor and metallic nanotubes) in SWCNT networks remains the single largest hurdle to developing a comprehensive view of ensemble nanotube electrical transport, a critical step toward their use in optoelectronics. Here, we systematically study temperature-dependent magnetoconductivity (MC) in networks of highly enriched semiconductor and metal SWCNT films. In the semiconductor-enriched network, we observe two-dimensional variable-range hopping conduction from 5 to 290 K. Low-temperature MC measurements reveal a large, negative MC from which we determine the wave-function localization length and Fermi energy density of states. In contrast, the metal-enriched film exhibits positive MC that increases with decreasing temperature, a behavior attributed to two-dimensional weak localization. Using this model, we determine the details of the carrier phase coherence and fit the temperature-dependent conductivity. These extensive measurements on type-enriched SWCNT networks provide insights that pave the way for the use of SWCNTs in solid-state devices.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Systèmes mésoscopiques et effet Hall quantique [cond-mat.mes-hall]

X. Wang, W. Gao, Xiaojian Li, Q. Zhang, Sébastien Nanot, et al.. Magnetotransport in type-enriched single-wall carbon nanotube networks. Physical Review Materials, 2018, 2, pp.116001. ⟨10.1103/PhysRevMaterials.2.116001⟩. ⟨hal-01934983⟩