Electron transport properties of carbon nanotube–graphene contacts

Abstract

The properties of carbon nanotube-graphene junctions are investigated with first-principles electronic structure and electron transport calculations. Contact properties are found to be key factors in determining the performance of nanotube based electronic devices. In a typical single-walled carbon nanotube-metal junction, there is a p-type Schottky barrier of up to ∼0.4 eV which depends on the nanotube diameter. Calculations of the Schottky barrier height in carbon nanotube-graphene contacts indicate that low barriers of 0.09 eV and 0.04 eV are present in nanotube-graphene contacts ((8,0) and (10,0) nanotubes, respectively). Junctions with a finite contact region are investigated with simulations of the current-voltage characteristics. The results suggest the suitability of the junctions for applications and provide insight to explain recent experimental findings.

Deformation of single‐walled carbon nanotubes by interaction with graphene: A first‐principles study

“…Owing to the similarity in electronic properties, it was found that no obvious Schottky barrier exists at metallic SWNT/graphene junction, which means that graphene is a good contact material for metallic CNTs while there is a Schottky barrier between semiconducting SWNT and graphene, resulting in a typical rectification properties and directionally field‐effect behavior . Such transport properties were also revealed by theoretical studies . Very recently, it was reported that the alignment of SWNTs on graphite surface is chirality dependent.…”

“…Besides the CNT‐graphene bulk hybrids, individual SWNT‐graphene systems are also of great importance. Very careful measurements on the transport behavior of SWNT‐graphene junctions show some interesting results . Owing to the similarity in electronic properties, it was found that no obvious Schottky barrier exists at metallic SWNT/graphene junction, which means that graphene is a good contact material for metallic CNTs while there is a Schottky barrier between semiconducting SWNT and graphene, resulting in a typical rectification properties and directionally field‐effect behavior .…”

Charge distribution of metallic single walled carbon nanotube–graphene junctions

“…For example, high conductance and low contact resistance were observed in CNT-CNT junctions [65,[72][73][74]. If only recently theoretical work succeeded to model the transport across a CNT-graphene junction [75] the first experiments in this field were performed more than a decade ago: conducting atomic force microscopy on CNT-graphite (i.e. highly oriented pyrolitic graphite) junctions were investigated using conductive atomic force microscopy in [76].…”

Effects of Geometry and Symmetry on Electron Transport through Graphene–Carbon-Chain Junctions

“…In the last years, many studies have addressed the contact effect in graphene-based transistors 35,36 . It has been shown that the contact type and contact position may determine the I ON to I OFF ratio 37,38 and contact resistance [39][40][41] . The height of the Schottky barrier at CNT-graphene contacts can be about one order lower than that at Pd-graphene contacts 38 .…”