Wafer-scale monodomain films of spontaneously aligned single-walled carbon nanotubes

Abstract

The one-dimensional character of electrons, phonons and excitons in individual single-walled carbon nanotubes leads to extremely anisotropic electronic, thermal and optical properties. However, despite significant efforts to develop ways to produce large-scale architectures of aligned nanotubes, macroscopic manifestations of such properties remain limited. Here, we show that large (>cm(2)) monodomain films of aligned single-walled carbon nanotubes can be prepared using slow vacuum filtration. The produced films are globally aligned within ±1.5° (a nematic order parameter of ∼1) and are highly packed, containing 1 × 10(6) nanotubes in a cross-sectional area of 1 μm(2). The method works for nanotubes synthesized by various methods, and film thickness is controllable from a few nanometres to ∼100 nm. We use the approach to create ideal polarizers in the terahertz frequency range and, by combining the method with recently developed sorting techniques, highly aligned and chirality-enriched nanotube thin-film devices. Semiconductor-enriched devices exhibit polarized light emission and polarization-dependent photocurrent, as well as anisotropic conductivities and transistor action with high on/off ratios.

Quasi-ballistic carbon nanotube array transistors with current density exceeding Si and GaAs

“…Recent progress in the alignment of CNTs from solution ( 11 ) and via chemical vapor deposition (CVD) ( 12 , 13 ) processes demonstrates promising scalability; however, achieving the optimal packing density of CNTs in an array and a high conductance per CNT remains to be a challenge. The ideal morphology of CNTs in an array FET consists of a relatively sparse layer of aligned CNTs with a pitch of more than 5 nm ( 10 ).…”

Pyridinic Nitrogen‐Enriched Carbon Nanogears with Thin Teeth for Superior Lithium Storage

“…Meanwhile, owing to the unique structures of 2D carbons which were unavailable from their bulk counterparts, including large open fl at structure that could shorten lithium diffusion pathway, excellent electronic transport properties, and excellent fl exibility that enabled to accommodate effi ciently the strain during long charge-discharge processes, 2D carbons were also expected to afford high-rate capability and good cyclic stability up to hundreds of cycles. [ 11 ] Very recently, both theoretical and experimental researches have disclosed that the chemical doping of 2D carbons with nitrogen could further improve their lithium storage capacities particularly at high current rates. [ 12 ] The enhanced electrochemical performances were ascribed to the highly electronegative nitrogen that could not only increase carbon interlayer distance and wettability for electrolyte, facilitating the fast lithium diffusion, but also create more defects in carbons, affording plenty of active sites for lithium storage.…”

A Two Dimensional Tunneling Resistance Transmission Line Model for Nanoscale Parallel Electrical Contacts

“…On macroscopic level, the exceptional intrinsic electrical properties 14,15 of CNTs become elusive 3,14,16 . Contact resistances between CNTs profoundly affect the electron transport and reduce the electrical conductivity of carbon nanofiber (CNF) [15][16][17] , and greatly limit the performance of CNT thin film based Field Effect Transistors (FETs) [18][19][20][21] . One can naturally expect these issues also arising from other novel two-dimensional materials (boron nitride, molybedenum sulfide, black phosphorus, etc) as well as new nano-composites.…”