Resistance simulations for junctions of SW and MW carbon nanotubes with various metal substrates

Abstract This theoretical study focuses on junctions between the carbon nanotubes (CNTs) and contacting metallic elements of a nanocircuit. Numerical simulations on the conductance and resistance of these contacts have been performed using the multiple scattering theory and the effective media cluster approach. Two models for CNT-metal contacts have been considered in this paper: a) first principles "liquid metal" model and b) semi-empirical model of "effective bonds" based on Landauer notions on ballistic conductivity. Within the latter, which is a more adequate description of chirality effects, we have simulated both single-wall (SW) and multi-wall (MW) CNTs with different morphology. Results of calculations on resistance for different CNT-Me contacts look quantitatively realistic (from several to hundreds kOhm, depending on chirality, diameter and thickness of MW CNT). The inter-wall transparency coefficient for MW CNT has been also simulated, as an indicator of possible 'radial current' losses

Real time polymer nanocomposites-based physical nanosensors: theory and modeling

Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences

Theoretical Simulations on Electric Properties of CNT-Me and GNR-Me Interconnects Using Effective Media Approach

Abstract To overcome disadvantages of nowadays microtechnology, a further miniaturization of electronic devices, high integration level as well as increase of both operation frequencies and power density is required, including the use of adequate materials and innovative chip interconnects. Due to their unique physical properties, especially due to a ballistic (without losses) mechanism of conductivity, carbon nanotubes (CNTs) and graphene nanoribbons (GNRs) attract a permanently growing technological interest, for example, as promising candidates for nanointerconnects in a high-speed electronics

NATO Advanced Research Workshop on Nanodevices and Nanomaterials for Ecological Security

  This book is devoted to a wide range of problems concerning applications of nanomaterials and nanodevices as effective solutions to modern ecological problems. Leading experts in nanoscience and nanotechnology present the key theoretical, experimental and implementation issues related to the creation and utilization of novel nanoscale devices to help ensure ecological security. The authors discuss appropriate nanotechnologies for minimizing various types of risk: to human life, technogenic risk, or indeed terrorist threats. Particular emphasis is placed on defining and studying the required materials properties, and – in the field – on nanoscale devices for sensors and monitoring

Nonregular nanosystems: theory and applications

This book presents a systemic view of nanophenomena in terms of disordered condensed media with characteristics arising at various hierarchical levels from nanoagents/nanoparticles through multiple technological interfaces to the creation of micro- or mesostructures with essential nanodimensional effects. These properties can be seen in various schemes for the functionalization of nanocarbon systems, namely, CNTs, GNRs, GNFs, carbon-based nanoaerogels, nanofoams, and so on, where nonregularities characterize surface nanointeractions and various nanointerconnects, resulting in both predictable and unpredictable effects. Beginning with nanosensing and finishing with other forms of functionalized nanomaterials, these effects will define the prospective qualities of future consumer nanoproducts and nanodevices. This book covers all aspects of nonregular nanosystems arising from the fundamental properties of disordered nanosized media, from electronic structure, surface nanophysics, and allotropic forms of carbon such as graphene and fullerenes including defect characterization, to spintronics and 3D device principles.  Nonregular Nanosystems will be of interest to students and specialists in various fields of nanotechnology and nanoscience, experts on surface nanophysics and nanochemistry, as well as managers dealing with marketing of nanoproducts and consumer behavior research

Simulation of electromagnetic properties in carbon nanotubes and graphene-based nanostructures

As carbon nanotubes (CNT) and graphene nanostructures (GNR) constitute the basis of high-speed nanoelectronics and nanosensors, we examine the fundamental properties of var- ious CNT-metal (Me), GNR-Me, and CNT-graphene interconnects. The cluster approach based on the multiple scattering theory as well as effective medium approximation were used to model the dispersion law, electronic density of states (DOS), and conductivity, etc. Multiple scattering problems were solved for nanostructures with radial (quantum dots) and axial (nanowires, nano- tubes) symmetry. Interconnect capacitances and impedances have been evaluated in the GHz and THz regimes. Parametrical numerical simulations of conductivity were carried out for zig-zag ðm;0Þ, armchair ðm;mÞ, and chiral ðm;nÞ CNTs, and the sensitivity of conductivity to the local electronic DOS in CNTs with local impurities (N and B atoms) was demonstrated. CNTs, CNT- Me, and GNR-Me based nanostructures are prospective nanosensor structures. © 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). (DOI: 10.1117/1.JNP.6.061706