graphene (material)

graphene (material)
Name	Graphene
Caption	Single layer of carbon atoms in a hexagonal lattice
Classification	Allotrope of carbon
Discovered	2004
Discoverers	Andre Geim, Konstantin Novoselov
Crystal system	Hexagonal
Lattice parameters	a = 2.46 Å
Density	0.77 mg/m^2 (single layer)
Band gap	Zero (semimetal)
Tensile strength	~130 GPa
Youngs modulus	~1 TPa
Thermal conductivity	2000–5000 W·m−1·K−1

graphene (material) is a two-dimensional monolayer of sp2-bonded carbon atoms arranged in a honeycomb lattice. It exhibits exceptional mechanical, electrical, thermal, and optical properties that have driven intense research and development across academic institutions, industrial laboratories, and national research centers worldwide. The discovery and isolation of graphene catalyzed recognition including the Nobel Prize in Physics awarded to Andre Geim and Konstantin Novoselov and spawned extensive research programs at organizations such as MIT, Stanford University, Max Planck Society, National Institute of Standards and Technology, and Tsinghua University.

Introduction

Graphene emerged from experiments connected to earlier studies on graphite, carbon nanotube, fullerene, and benzene chemistry, linking the work of laboratories from University of Manchester and research groups at Columbia University, University of California, Berkeley, University of Cambridge, University of Oxford, and University of Tokyo. The field intersects topics like solid-state physics, materials science, nanotechnology, and condensed matter physics, with milestones including seminal papers, patents, and commercialization efforts by companies such as Sony, IBM, Samsung, BASF, Graphenea, First Graphene, and Vorbeck Materials.

Structure and Properties

The hexagonal lattice produces Dirac cones at the K and K' points of the Brillouin zone, a feature central to models developed in band theory and measured in experiments at facilities like CERN, European Synchrotron Radiation Facility, Argonne National Laboratory, and Brookhaven National Laboratory. Electrons behave as massless Dirac fermions, a concept related to the Dirac equation and explored alongside phenomena such as the quantum Hall effect, Klein tunneling, and Berry phase. Mechanical properties derive from sp2 hybridization and are quantified using methods from continuum mechanics and instruments at National Institute for Materials Science. Thermal transport links to studies in phonon dispersion and experiments using facilities like Oak Ridge National Laboratory and Los Alamos National Laboratory. Optical transparency and plasmonic behavior connect graphene research to projects at Bell Labs and Riken.

Production and Synthesis Methods

Methods include mechanical exfoliation pioneered at University of Manchester, chemical vapor deposition (CVD) developed by teams at Columbia University and MIT, epitaxial growth on silicon carbide by researchers at Georgia Tech and University of Maryland, liquid-phase exfoliation advanced by groups at Imperial College London and University of Cambridge, and chemical synthesis routes related to work at IBM Research and University of Bologna. Scale-up approaches are pursued by industrial partners such as Haydale, CVD Equipment Corporation, Graphene Platform, and Samsung Advanced Institute of Technology. Substrate engineering often references materials like copper, nickel, silicon dioxide, and hexagonal boron nitride, with transfer techniques evolved in labs including EPFL and University of Illinois at Urbana–Champaign.

Characterization Techniques

Characterization employs Raman spectroscopy instruments developed alongside groups at Horiba, Renishaw, and facilities such as Diamond Light Source; transmission electron microscopy in centers like EMBL and Lawrence Berkeley National Laboratory; scanning tunneling microscopy at IBM Zurich Research Laboratory; atomic force microscopy common in ETH Zurich and University of Pennsylvania labs; X-ray photoelectron spectroscopy at ALS (Berkeley); and electrical measurements using cryostats and magnet systems at Delft University of Technology and University of California, Santa Barbara. Data analysis leverages collaborations with National Graphene Institute and computational modeling at Lawrence Livermore National Laboratory.

Applications

Graphene applications span sectors represented by entities like Boeing, Airbus, Toyota, Volkswagen, Siemens, Intel, Samsung Electronics, Sony, LG Electronics, and Johnson Matthey. Examples include conductive inks and transparent electrodes used in displays by companies such as Samsung Display and LG Display; composite reinforcement pursued with BASF, 3M, and Toray Industries; energy-storage elements in batteries and supercapacitors targeted by Tesla, Panasonic, Samsung SDI, and Maxwell Technologies; sensors and biosensors developed in collaboration with Roche, Siemens Healthineers, Medtronic, and GE Healthcare; photonics and modulators studied at Bell Labs and Nokia Bell Labs; membranes and desalination concepts explored by National University of Singapore; and quantum devices pursued at Microsoft Station Q and IBM Q. Research also addresses composites in sports equipment associated with brands like Wilson Sporting Goods and Adidas.

Toxicity, Safety, and Environmental Impact

Toxicological and environmental studies are conducted by institutions including World Health Organization, Environmental Protection Agency, European Chemicals Agency, University of California, Davis, Karolinska Institute, and University of Toronto. Concerns involve inhalation exposure for workers in manufacturing settings at facilities operated by First Graphene and Graphenea; lifecycle analyses are performed by groups at Fraunhofer Society, National Renewable Energy Laboratory, and TNO. Regulatory frameworks and standards are influenced by agencies such as International Organization for Standardization, Occupational Safety and Health Administration, and European Commission policy units, while remediation and recycling research involves teams at Argonne National Laboratory and Rutgers University.

Economic and Commercial Aspects

Commercialization pathways include startups like Graphenea, First Graphene, Directa Plus, Talga Resources, Versarien, and Applied Graphene Materials, alongside established firms such as BASF, Haydale, and Samsung. Investment, market analyses, and reports are produced by McKinsey & Company, Deloitte, Bloomberg, Goldman Sachs, and Boston Consulting Group, while intellectual property landscapes involve patent portfolios managed by IBM, Samsung, Nikon, Dow Chemical, and BASF. National strategies incorporate initiatives from European Union, United States Department of Energy, China Ministry of Science and Technology, Japan Science and Technology Agency, UK Research and Innovation, and Australian Research Council to foster supply chains, manufacturing, and workforce development.

Category:Carbon allotropes Category:Two-dimensional materials