Taking advantage of graphene defects

graphene
Scanning tunnelling microscopy (STM) image of graphene on Ir(111). The image size is 15 nm × 15 nm. Credit: ESRF

A potential application in security screening: new theoretical model for estimation of electric current rectification in graphene

Electronic transport in graphene contributes to its characteristics. Now, a Russian scientist proposes a new to describe graphene with defects-in the form of artificial triangular holes-resulting in the rectification of the within the material. Specifically, the study provides an analytical and numerical theory of the so-called ratchet effect. Its result is a direct current under the action of an oscillating electric field, due to the skew of electronic carriers by coherently oriented defects in the material. These findings by Sergei Koniakhin from the Ioffe Physical Technical Institute and the Academic University Nanotechnology Research and Education Centre, both affiliated with the Russian Academy of Sciences in St. Petersburg, are published in European Physical Journal B.

Koniakhin studied the scattering on various types of triangular defects, including the scattering on a cluster in the shape of a solid triangle. To do so, he used a theoretical framework ranging from the scale of the graphene sample-the so-called classical framework-to the atomic level, at the quantum mechanical scale. The study also focused on the example of scattering on three-point defects placed at the corners of a triangle. The author analysed symmetric and asymmetric parts of scattering rates of electrons and implemented them into the classical Boltzmann kinetic theory.

The numerical estimation of the current rectification effect resulting from this work has yet to be confirmed experimentally. However, the numerical values obtained can directly be compared with future experimental data. Such theoretical studies of with triangular could be used in the detection of terahertz radiation, which has applications in security screening detectors. These are based on the photogalvanic effect, which is the appearance of electric current as result of irradiation of a device or sample material by light.


Explore further

Graphene nanoribbons as electronic switches

More information: Koniakhin, S.V. (2014). "Ratchet effect in graphene with trigonal clusters." European Physical Journal B. DOI: 10.1140/epjb/e2014-50434-4
Journal information: European Physical Journal B

Provided by Springer
Citation: Taking advantage of graphene defects (2014, September 24) retrieved 4 April 2020 from https://phys.org/news/2014-09-advantage-graphene-defects.html
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.
0 shares

Feedback to editors

User comments