Site- and alignment-controlled growth of graphene nanoribbons from nickel nanobars

Abstract

Graphene nanoribbons combine the unique electronic and spin properties of graphene with a transport gap that arises from quantum confinement and edge effects. This makes them an attractive candidate material for the channels of next-generation transistors. Nanoribbons can be made in a variety of ways, including lithographic, chemical and sonochemical approaches, the unzipping of carbon nanotubes, the thermal decomposition of SiC and organic synthesis. However, the reliable site and alignment control of nanoribbons with high on/off current ratios remains a challenge. Here we control the site and alignment of narrow (∼23 nm) graphene nanoribbons by directly converting a nickel nanobar into a graphene nanoribbon using rapid-heating plasma chemical vapour deposition. The nanoribbons grow directly between the source and drain electrodes of a field-effect transistor without transfer, lithography and other postgrowth treatments, and exhibit a clear transport gap (58.5 meV), a high on/off ratio (>10(4)) and no hysteresis. Complex architectures, including parallel and radial arrays of supported and suspended ribbons, are demonstrated. The process is scalable and completely compatible with existing semiconductor processes, and is expected to allow integration of graphene nanoribbons with silicon technology.

Deposition, Characterization, and Thin-Film-Based Chemical Sensing of Ultra-long Chemically Synthesized Graphene Nanoribbons

“…1,2 The creation of a bandgap in graphene is essential for the utilization of graphene in digital integrated circuits so that switching off the channel can be realized. Recently, lots of efforts were put into generating GNRs with various widths and lengths using lithographical [3][4][5] , chemical [6][7][8] and various other techniques [9][10][11][12][13][14][15][16][17] . However, patterning graphene using top-down approaches create GNRs with rough edges which can degrade the carrier transport.…”

Direct growth of aligned graphitic nanoribbons from a DNA template by chemical vapour deposition

“…In addition, three methods for the direct synthesis of nanoribbons have been reported including a bottomup synthesis from molecular components 9 and an epitaxial growth from SiC utilizing the preferential precipitation of graphene from a pre-patterned facet 10 . However, these methods are limited in the dimensions of the resultant structures 11 . A scalable method for growth of aligned ribbons with widths o10 nm would have a significant impact on the development of next-generation highperformance electronic devices.…”

Velocity renormalization and Dirac cone multiplication in graphene superlattices with various barrier-edge geometries

“…Further studies may focus on systems with mixed chiral orientation different than pure armchair or zigzag orientation reproducing certain experimental conditions. Nevertheless, much improved control of edge geometry (using a bottom-up approach for chemical synthesis [52][53][54][55] ) make the present systems promising for electron collimation experiments. The Kubo-Greenwood approach was nevertheless helpful in this article to compute the energy dependent velocity at any intermediate angles as shown in Fig 13. …”