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Lecture

Graphene: Quantum Properties and Nanoribbons

In course

MSE-484: Properties of semiconductors and related nanostructures

This course explains the origin of optical and electrical properties of semiconductors. The course elaborates how they change when the semiconductors are reduced to sizes of few nanometers. The course provides also the basis to use software to calculate th ...

Description

This lecture explores the unique electronic properties of graphene, including its quantum conductance and special electronic properties. It delves into the fabrication processes of graphene nanoribbons, the effects of quantum confinement, and the appearance of zero conductivity. The presentation also covers the ideal and disordered graphene edges, their impact on band structure, and the morphology of graphene edges. The lecture concludes with a discussion on the potential applications of graphene nanoribbons in various fields.

Instructors (2)

Anna Fontcuberta i Morral

2014 Associate Professor at the Institut des Matériaux, EPFL 2008 Assistant Professor Tenure Track at the Institut des Matériaux, EPFL 2009 Habilitation in Physics, Technische Universität München 2005-2010 Marie Curie Excellence Grant Team Leader at Walter Schottky Institut, Technische Universität München, on leave from Centre National de la Recherche Scientifique (CNRS, France) 2004-2005 Visiting Scientist at the California Institute of Technology, on leave from CNRS; Senior Scientist and co-founder of Aonex Technologies (a startup company for large area layer transfer of InP and Ge on foreign substrates for the main application of multi-junction solar cells) 2003 Permanent Research Fellow at CNRS, Ecole Polytechnique, France 2001-2002 Postdoctoral Scholar at the California Institute of Technology Study of wafer bonding and hydrogen-induced exfoliation processes for integration of mismatched materials in views of photovoltaic applications Sponsor: Professor Harry A. Atwater 1998-2001 PhD in Materials Science, Ecole Polytechnique Study of polymorphous silicon: growth mechanisms, optical and structural properties. Application to Solar Cells and Thin Film Transistors Advisor: Pere Roca i Cabarrocas 1997-1998 Diplôme dEtudes Approfondis (D.E.A.) in Materials Science at Université Paris XI, France . 1993-1997 BA in Physics at Universitat de Barcelona

Valerio Piazza

Official source

Related concepts (32)

Graphene

Graphene (ˈgræfiːn) is an allotrope of carbon consisting of a single layer of atoms arranged in a hexagonal lattice nanostructure. The name is derived from "graphite" and the suffix -ene, reflecting the fact that the graphite allotrope of carbon contains numerous double bonds. Each atom in a graphene sheet is connected to its three nearest neighbors by σ-bonds and a delocalised π-bond, which contributes to a valence band that extends over the whole sheet.

Graphene nanoribbon

Graphene nanoribbons (GNRs, also called nano-graphene ribbons or nano-graphite ribbons) are strips of graphene with width less than 100 nm. Graphene ribbons were introduced as a theoretical model by Mitsutaka Fujita and coauthors to examine the edge and nanoscale size effect in graphene. Large quantities of width-controlled GNRs can be produced via graphite nanotomy, where applying a sharp diamond knife on graphite produces graphite nanoblocks, which can then be exfoliated to produce GNRs as shown by Vikas Berry.

Potential applications of graphene

Potential graphene applications include lightweight, thin, and flexible electric/photonics circuits, solar cells, and various medical, chemical and industrial processes enhanced or enabled by the use of new graphene materials. In 2008, graphene produced by exfoliation was one of the most expensive materials on Earth, with a sample the area of a cross section of a human hair costing more than

1,000 as of April 2008 (about

100,000,000/cm2). Since then, exfoliation procedures have been scaled up, and now companies sell graphene in large quantities.

Bilayer graphene

Bilayer graphene is a material consisting of two layers of graphene. One of the first reports of bilayer graphene was in the seminal 2004 Science paper by Geim and colleagues, in which they described devices "which contained just one, two, or three atomic layers" Bilayer graphene can exist in the AB, or Bernal-stacked form, where half of the atoms lie directly over the center of a hexagon in the lower graphene sheet, and half of the atoms lie over an atom, or, less commonly, in the AA form, in which the layers are exactly aligned.

Electronic band structure

In solid-state physics, the electronic band structure (or simply band structure) of a solid describes the range of energy levels that electrons may have within it, as well as the ranges of energy that they may not have (called band gaps or forbidden bands). Band theory derives these bands and band gaps by examining the allowed quantum mechanical wave functions for an electron in a large, periodic lattice of atoms or molecules.

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