Computer simulations suggest graphynes may be even more useful than graphene

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. More information: Competition for Graphene: Graphynes with Direction-Dependent Dirac Cones, Phys. Rev. Lett. 108, 086804 (2012) DOI: 10.1103/PhysRevLett.108.086804AbstractThe existence of Dirac cones in the band structure of two-dimensional materials accompanied by unprecedented electronic properties is considered to be a unique feature of graphene related to its hexagonal symmetry. Here, we present other two-dimensional carbon materials, graphynes, that also possess Dirac cones according to first-principles electronic structure calculations. One of these materials, 6,6,12-graphyne, does not have hexagonal symmetry and features two self-doped nonequivalent distorted Dirac cones suggesting electronic properties even more amazing than that of graphene.via Focus Citation: Computer simulations suggest graphynes may be even more useful than graphene (2012, March 5) retrieved 18 August 2019 from https://phys.org/news/2012-03-simulations-graphynes-graphene.html © 2011 PhysOrg.com Greaphene, it has been noted, has conduction electrons whose energies are directly proportional to their momentum. It has also been noted that when their energy levels are plotted in three dimensions, they take on the shape of a Dirac cone. Because of this unique relationship, the conduction electrons behave as if they were massless, allowing them to travel at very near the speed of light, a very useful property when looking to improve on such things as current transistor technology.Unlike graphene, which has single or double bonds, graphyne can have double or triple bonds, and it’s not restricted to just a hexagonal pattern. Indeed the number of patterns that it can exist as appears to be almost limitless.In this new research, the team looked at three graphyne pattern types with their computer simulation and found all of them capable of producing a Dirac cone, albeit in a slightly different shape; but perhaps most importantly, one of them called 6,6,12-graphyne, which exists as a pattern of rectangles, should allow electrons to travel in just one direction. Because of this, the researchers say, materials could be made that didn’t require “dopant” or nancarbon atoms to provide a source for the electrons, such as the case with graphene.Despite the fact that only very small pieces of graphyne have ever been made, researchers are excited about this research because it has shown that many graphyne pattern types exist that are capable of producing a Dirac cone, which means many other materials may be capable of doing so as well. The secrets of tunneling through energy barrierslast_img

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