Electrical conductivity of single-wall carbon nanotube films in strong electric field

Abstract

Carrier transport features in single-wall carbon nanotube (SWCNT) films under strong electric fields (up to 10 5 V/cm) are presented. Application of electrical pulses of nanosecond duration allowed to minimize Joule heating and resolve intrinsic nonlinearities with the electric field. Investigations within a wide range of temperatures-4.2-300 K-indicated that carrier localization as well as tunneling through the insulating barriers between conducting regions takes place in SWCNT films. Crossover from semiconducting behavior to metallic behavior in strong electric field is described using the fluctuation induced tunneling model and assuming that the conducting regions demonstrate characteristic metallic conductivity. V

The Effects of Lengths of Flavin Surfactant N-10-Alkyl Side Chains on Promoting Dispersion of a High-Purity and Diameter-Selective Single-Walled Nanotube

“…While the 0.61 mM dispersion is unstable, the 2.44 mM FC8 dispersion exhibits sharp absorption features originating from HiPco SWNT, as shown in Figure 2D. Interestingly, the corresponding PLE map (Figure 2E) exhibits smaller-d t chirality enrichments of SWNT in the order (8,4), (9,5), (8,6), (7,5), and (6,5) tubes. Their average d t is 0.86 nm, which contrasts sharply with that of the 2.44 mM FC12-HiPco dispersion: The absorption results (Figure S5A) show much larger d t distribution, with e S 11 extending up to 1600 nm, and the corresponding PLE map (Figure S5B) shows that PLbased chiralities range from (6,5) to (10,8) with a number-average d t of 0.96 nm.…”

“…PL-intensity based chirality abundances of FC12-and FC8-HiPco were illustrated as Weisman plots in Figure S5C. Clearly, FC8-HiPco exhibits smaller d t enrichment whose most abundant species are (8,4) as 38% as compared to FC12-HiPco in which comparably larger-d t (9,5), (8,6), and (7,6) altogether accounts for 32%. These results indicate that d t -selective SWNT dispersion originates from l S .…”

“…Figure 6E depicts γn C values for flavin surfactants based on three helical motifs (i.e., 7 1 , 8 1 , and 9 1 helices). Several SWNT chiralities [i.e., mainly (8,4) and (7,5)] observed with HiPco SWNT dispersion suggest that FC8 could exhibit a 7 1 helix. Therefore, Figure 6E considers the flavin helix polymorphism.…”

“…First, the as-prepared sample exhibits (9,5), (8,6), and (7,5) enrichment as major chiralities and does not change significantly after FC8 addition. However, the aging period induces (8,4) and (7,5) enrichment by lowering I PL of the larger d t SWNT (see the max I PL of each map). Brief bath-sonication of this sample partially recovered the PL-based SWNT abundance (i.e., (9,5), (8,6), and (7,5) enrichment) similar to that of the as-prepared sample.…”

Electronic Conduction in Disordered Carbon Materials

“…semiconductor) component at high temperatures [Ravi et al 2013]. Meanwhile, some other SWNT networks exhibit a parallel combination of fluctuation assisted tunnelling (FAT) and quasi-1D metallic conduction at high applied electric fields [Seliuta et al 2013].…”