Scaling analysis of electron transport through metal-semiconducting carbon nanotube interfaces

Evolution from the molecular limit to the bulk limit

Yongqiang Xue, Mark A Ratner

Research output: Contribution to journalArticle

44 Citations (Scopus)

Abstract

We present a scaling analysis of electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube length within the coherent transport regime, which takes fully into account atomic-scale electronic structure and three-dimensional electrostatics of the metal-nanotube interface using a real-space Green's function based self-consistent tight-binding theory. As the first example, we examine devices formed by attaching finite-size single-wall carbon nanotubes (SWNT) to both high- and low-work function metallic electrodes through the dangling bonds at the end, where the length of the SWNT molecule varies from the molecular limit to the bulk limit and the strength of metal-SWNT coupling varies from the strong coupling to the weak coupling limit. We analyze the nature of Schottky barrier formation at the metal-nanotube interface by examining the electrostatics, the band lineup and the conductance of the metal-SWNT molecule-metal junction as a function of the SWNT molecule length and metal-SWNT coupling strength. We show that the confined cylindrical geometry and the atomistic nature of electronic processes across the metal-SWNT interface leads to a different physical picture of band alignment from that of the planar metal-semiconductor interface. We analyze the temperature and length dependence of the conductance of the SWNT junctions, which shows a transition from tunneling- to thermal activation-dominated transport with increasing nanotube length. The temperature dependence of the conductance is much weaker than that of the planar metal-semiconductor interface due to the finite number of conduction channels within the SWNT junctions. We find that the current-voltage characteristics of the metal-SWNT molecule-metal junctions are sensitive to models of the potential response to the applied source/drain bias voltages. Our analysis applies in general to devices based on quasi-one-dimensional nanostructures including molecules, carbon nanotubes, and semiconductor nanowires.

Original languageEnglish
Article number205416
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume70
Issue number20
DOIs
Publication statusPublished - Nov 2004

Fingerprint

Carbon Nanotubes
Carbon nanotubes
Metals
carbon nanotubes
scaling
metals
electrons
Nanotubes
nanotubes
Molecules
molecules
Semiconductor materials
Electron Transport
Electrostatics
electrostatics
temperature dependence
Dangling bonds
electric potential
Current voltage characteristics
Bias voltage

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

@article{53fdae3877424215b109f3b1928b580d,
title = "Scaling analysis of electron transport through metal-semiconducting carbon nanotube interfaces: Evolution from the molecular limit to the bulk limit",
abstract = "We present a scaling analysis of electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube length within the coherent transport regime, which takes fully into account atomic-scale electronic structure and three-dimensional electrostatics of the metal-nanotube interface using a real-space Green's function based self-consistent tight-binding theory. As the first example, we examine devices formed by attaching finite-size single-wall carbon nanotubes (SWNT) to both high- and low-work function metallic electrodes through the dangling bonds at the end, where the length of the SWNT molecule varies from the molecular limit to the bulk limit and the strength of metal-SWNT coupling varies from the strong coupling to the weak coupling limit. We analyze the nature of Schottky barrier formation at the metal-nanotube interface by examining the electrostatics, the band lineup and the conductance of the metal-SWNT molecule-metal junction as a function of the SWNT molecule length and metal-SWNT coupling strength. We show that the confined cylindrical geometry and the atomistic nature of electronic processes across the metal-SWNT interface leads to a different physical picture of band alignment from that of the planar metal-semiconductor interface. We analyze the temperature and length dependence of the conductance of the SWNT junctions, which shows a transition from tunneling- to thermal activation-dominated transport with increasing nanotube length. The temperature dependence of the conductance is much weaker than that of the planar metal-semiconductor interface due to the finite number of conduction channels within the SWNT junctions. We find that the current-voltage characteristics of the metal-SWNT molecule-metal junctions are sensitive to models of the potential response to the applied source/drain bias voltages. Our analysis applies in general to devices based on quasi-one-dimensional nanostructures including molecules, carbon nanotubes, and semiconductor nanowires.",
author = "Yongqiang Xue and Ratner, {Mark A}",
year = "2004",
month = "11",
doi = "10.1103/PhysRevB.70.205416",
language = "English",
volume = "70",
journal = "Physical Review B-Condensed Matter",
issn = "1098-0121",
publisher = "American Physical Society",
number = "20",

}

TY - JOUR

T1 - Scaling analysis of electron transport through metal-semiconducting carbon nanotube interfaces

T2 - Evolution from the molecular limit to the bulk limit

AU - Xue, Yongqiang

AU - Ratner, Mark A

PY - 2004/11

Y1 - 2004/11

N2 - We present a scaling analysis of electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube length within the coherent transport regime, which takes fully into account atomic-scale electronic structure and three-dimensional electrostatics of the metal-nanotube interface using a real-space Green's function based self-consistent tight-binding theory. As the first example, we examine devices formed by attaching finite-size single-wall carbon nanotubes (SWNT) to both high- and low-work function metallic electrodes through the dangling bonds at the end, where the length of the SWNT molecule varies from the molecular limit to the bulk limit and the strength of metal-SWNT coupling varies from the strong coupling to the weak coupling limit. We analyze the nature of Schottky barrier formation at the metal-nanotube interface by examining the electrostatics, the band lineup and the conductance of the metal-SWNT molecule-metal junction as a function of the SWNT molecule length and metal-SWNT coupling strength. We show that the confined cylindrical geometry and the atomistic nature of electronic processes across the metal-SWNT interface leads to a different physical picture of band alignment from that of the planar metal-semiconductor interface. We analyze the temperature and length dependence of the conductance of the SWNT junctions, which shows a transition from tunneling- to thermal activation-dominated transport with increasing nanotube length. The temperature dependence of the conductance is much weaker than that of the planar metal-semiconductor interface due to the finite number of conduction channels within the SWNT junctions. We find that the current-voltage characteristics of the metal-SWNT molecule-metal junctions are sensitive to models of the potential response to the applied source/drain bias voltages. Our analysis applies in general to devices based on quasi-one-dimensional nanostructures including molecules, carbon nanotubes, and semiconductor nanowires.

AB - We present a scaling analysis of electronic and transport properties of metal-semiconducting carbon nanotube interfaces as a function of the nanotube length within the coherent transport regime, which takes fully into account atomic-scale electronic structure and three-dimensional electrostatics of the metal-nanotube interface using a real-space Green's function based self-consistent tight-binding theory. As the first example, we examine devices formed by attaching finite-size single-wall carbon nanotubes (SWNT) to both high- and low-work function metallic electrodes through the dangling bonds at the end, where the length of the SWNT molecule varies from the molecular limit to the bulk limit and the strength of metal-SWNT coupling varies from the strong coupling to the weak coupling limit. We analyze the nature of Schottky barrier formation at the metal-nanotube interface by examining the electrostatics, the band lineup and the conductance of the metal-SWNT molecule-metal junction as a function of the SWNT molecule length and metal-SWNT coupling strength. We show that the confined cylindrical geometry and the atomistic nature of electronic processes across the metal-SWNT interface leads to a different physical picture of band alignment from that of the planar metal-semiconductor interface. We analyze the temperature and length dependence of the conductance of the SWNT junctions, which shows a transition from tunneling- to thermal activation-dominated transport with increasing nanotube length. The temperature dependence of the conductance is much weaker than that of the planar metal-semiconductor interface due to the finite number of conduction channels within the SWNT junctions. We find that the current-voltage characteristics of the metal-SWNT molecule-metal junctions are sensitive to models of the potential response to the applied source/drain bias voltages. Our analysis applies in general to devices based on quasi-one-dimensional nanostructures including molecules, carbon nanotubes, and semiconductor nanowires.

UR - http://www.scopus.com/inward/record.url?scp=42749103486&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=42749103486&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.70.205416

DO - 10.1103/PhysRevB.70.205416

M3 - Article

VL - 70

JO - Physical Review B-Condensed Matter

JF - Physical Review B-Condensed Matter

SN - 1098-0121

IS - 20

M1 - 205416

ER -