Impact of carbon nanotube length on electron transport in aligned carbon nanotube networks

Journal Article · Mon Feb 02 04:00:00 EST 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4907608· OSTI ID:22420267

Lee, Jeonyoon; Stein, Itai Y. ^[1]; Devoe, Mackenzie E. ^[2]; Lewis, Diana J.; Lachman, Noa; Buschhorn, Samuel T.; Kessler, Seth S. ^[3]

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1. Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)
2. Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, Massachusetts 02139 (United States)
3. Metis Design Corporation, 205 Portland St., Boston, Massachusetts 02114 (United States)

Here, we quantify the electron transport properties of aligned carbon nanotube (CNT) networks as a function of the CNT length, where the electrical conductivities may be tuned by up to 10× with anisotropies exceeding 40%. Testing at elevated temperatures demonstrates that the aligned CNT networks have a negative temperature coefficient of resistance, and application of the fluctuation induced tunneling model leads to an activation energy of ≈14 meV for electron tunneling at the CNT-CNT junctions. Since the tunneling activation energy is shown to be independent of both CNT length and orientation, the variation in electron transport is attributed to the number of CNT-CNT junctions an electron must tunnel through during its percolated path, which is proportional to the morphology of the aligned CNT network.

• OSTI ID: 22420267
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 5 Vol. 106; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ACTIVATION ENERGY
CARBON NANOTUBES
ELECTRIC CONDUCTIVITY
ELECTRIC CONTACTS
ELECTRON TRANSFER
TUNNEL EFFECT