Wide Contact Structures for Low-Noise Nanochannel Devices Based on a Carbon Nanotube Network

Abstract

We have developed a wide contact structure for low-noise nanochannel devices based on a carbon nanotube (CNT) network. This low-noise CNT network-based device has a dumbbell-shaped channel, which has wide CNT/electrode contact regions and, in effect, reduces the contact noise. We also performed a systematic analysis of structured CNT networks and established an empirical formula that can explain the noise behavior of arbitrary-shaped CNT network-based devices including the effect of contact regions and CNT alignment. Interestingly, our analysis revealed that the noise amplitude of aligned CNT networks behaves quite differently compared with that of randomly oriented CNT networks. Our results should be an important guideline in designing low-noise nanoscale devices based on a CNT network for various applications such as a highly sensitive low-noise sensor.

Scanning Noise Microscopy on Graphene Devices

“…As a next step, we developed an empirical model to obtain the noise amplitude A ch of the graphene strip channel from the measured total noise amplitude A tot . The total noise amplitude A tot measured in the SNM experiment can be expressed by the noise amplitude values of individual resistance parts in the current path like, A normalt normalo normalt = [ A c h R c h 2 + A e l e c R e l e c 2 + A t i p R t i p 2 ] / R normalt normalo normalt 2 = [ A c h R c h 2 + D ] / false( R normalc normalh + C false) 2 where A ch , A cont , and A tip represent the noise amplitude of the resistance parts in the graphene strip channel, the Au electrode contact, and the Pt tip, respectively. D is defined as A elec R elec 2 + A tip R tip 2 , representing the noise from the Au electrodes and the P...…”

“…Since we utilized the same Pt tip for entire SNM experiment, we can assume that D remained constant during our measurement. Finally, if we assumed a general power law A ch ≅ α × R ch ν regarding the noise from the graphene strip, eq can be written as A normalt normalo normalt = [ false( normalα · R normalc normalh normalν false) · R c h 2 + D ] / false( R normalc normalh + C false) 2 where the α and ν are the coefficient and the scaling factor of the channel resistance, respectively. Thus, the characteristic parameters (α and ν) of the noise from the graphene strip channel can be obtained by fitting the graph of the measured A tot versus the estimated R ch using eq (Figure S3 in the Supporting Information).…”

“…Thus, the characteristic parameters (α and ν) of the noise from the graphene strip channel can be obtained by fitting the graph of the measured A tot versus the estimated R ch using eq (Figure S3 in the Supporting Information). − …”

Nanobuds promote heat welding of carbon nanotubes at experimentally-relevant temperatures

“…9,12 Carbon nanotube network based devices has been intensively studied in recent years. [13][14][15][16][17] Interconnected network of carbon nanotubes (CNTs) is a promising material that is able to translate the unique properties of individual CNTs to threedimensional space. Although some novel materials based on carbon nanotube networks have been constructed; however, the extraordinary properties of the individual CNTs such as their exceptional mechanical property are oen lost in these materials because the CNT junctions are formed by other chemical components instead of carbon-carbon (C-C) covalent bonds.…”

Accelerating Gas Adsorption on 3D Percolating Carbon Nanotubes

“…However, SWCNT films obtained by means of facile solution-processing often consist of nanotubes with a sub-monolayer surface coverage and conduct current via a 2D percolation network 13 . A 3D structure cannot establish due to a so-called self-limiting mechanism where the first-adsorbed SWCNTs tend to block further nanotube adsorption onto the substrate 14 . A general strategy is, therefore, to form a 3D high-specific-surface mesoporous composite by dispersing the SWCNTs in a functional polymer matrix of high gas permeability 15 .…”