Introduction. Carbon-based electronics: fundamentals and device applications

Abstract

Carbon-based materials offer a number of exciting possibilities for both new science and applications. Many of these are based on the novel band structure of graphene, by which solids mimic the properties of relativisitic fermions and which offers the potential for high speed nanoscale electronics. When sheets of graphene are rolled up to make carbon nanotubes, further interesting properties are found; for example, both semiconducting and metallic nanotubes able to be produced. The novel properties of these new materials, together with the already remarkable properties of diamond itself, are discussed by a series of experts who came together in May 2007 to discuss and debate the potential for future development. Keywords: graphene; diamond; carbon nanotubesFor over 50 years, silicon has dominated the electronics industry, with progress inexorably following the prophetic statement from Gordon Moore, the co-founder of Intel, that the number of transistors on a silicon chip would grow exponentially with time, doubling every 2 years (Moore's law). This growth cannot be maintained forever and so the search is on to find and use new materials which may be able to produce higher performance and better functionality. A good candidate is carbon, which comes in a variety of fascinating forms with dramatic physical and electronic properties. Whereas the physical properties of graphite and diamond have been investigated for many years, the potential for electronic applications of other allotropes of carbon has only been appreciated relatively recently. Since the pioneering work of Iijima (1991) on single-wall carbon nanotubes (CNTs), there has been rapid progress in our understanding of their remarkable properties. The recent discovery of graphene, a single atomic monolayer of carbon, and its fabrication into a field-effect transistor in 2004 by Geim and colleagues in Manchester (Novoselov et al. 2004), has opened up a new field of fundamental physics and offers exciting prospects for new electronic devices. This discussion meeting examines some of the latest developments in the science and technology of CNTs and graphene. There are also four papers in this issue on diamond, which has much to offer as an electronic material. Graphene consists of a single sheet of carbon atoms bonded in the sp 2 configuration of a hexagonal lattice structure. This was studied theoretically 60 years ago by Wallace (1947) as the first approximation to understand the electronic properties of graphite. His work showed that graphene has a unique band structure in which the conduction and valence bands just touch each other, forming an exactly zero-band gap semiconductor (also known as a semi-metal). The energy dispersion relation of the two bands is therefore linear in wave vector, k, and they cross at the K points of the two-dimensional Brillouin zone. This property, in combination with the hexagonal crystal lattice symmetry, makes the electrons behave as if they were massless fermions, governed by Dirac's equation, with a relativistic limiting ...

Present Status and Future Prospects of Jute in Nanotechnology: A Review

“…A single sheet of carbon atoms bound in the sp 2 configuration of a hexagonal lattice structure makes up graphene. Graphene has a peculiar band structure in which the conduction and valence bands are almost touching, creating a semiconductor with an exact zero‐band difference (also known as a semi‐metal) [278] . Longyan et al [279] .…”

Graphene to graphite: electronic changes within DFT calculations

“…Recently, carbon-based materials such as graphene (a single hexagonal layer of carbon atoms) and graphite (threedimensional hexagonal structure of carbon atoms) have generated a lot of interest due to their exotic electronic properties [1,2]. From the electronic structure point of view, monolayer graphene has a linear band dispersion near the corner (K) point of its Brillouin zone originating from the π and π * bondings between the two carbon basis atoms within the hexagonal unit cell.…”

Writing with ring currents: selectively hydrogenated polycyclic aromatics as finite models of graphene and graphane

“…Although much of the avalanche of recent research on graphene and related carbon nanostructures has been concentrated on physical properties [1][2][3], strategies for chemical functionalization of these materials are receiving increasing attention [4][5][6][7][8][9][10][11][12]. Controlled 1.…”