Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

On the way to breaking the terahertz barrier for graphene nanoelectronics

16.07.2015

Simple thermodynamics defines the performance of ultrafast graphene transistors and photodetectors

A team of scientists at the Max Planck Institute for Polymer Research (MPI-P) discovered that electrical conduction in graphene on the picosecond timescale - a picosecond being one thousandth of one billionth of a second - is governed by the same basic laws that describe the thermal properties of gases.


Interaction of the terahertz field with graphene leads to efficient electron heating, which in turn strongly changes graphene conductivity.

Credit: © Zoltan Mics / MPIP

This much simpler thermodynamic approach to the electrical conduction in graphene will allow scientists and engineers not only to better understand but also to improve the performance of graphene-based nanoelectronic devices.

The researchers found that the energy of ultrafast electrical currents passing through graphene is very efficiently converted into electron heat, making graphene electrons behave just like a hot gas. "The heat is distributed evenly over all electrons.

And the rise in electronic temperature, caused by the passing currents, in turn has a strong effect on the electrical conduction of graphene" explains Professor Mischa Bonn, Director at the MPI-P. The study, entitled "Thermodynamic picture of ultrafast charge transport in graphene", has recently been published in Nature Communications.

Graphene - a single sheet of carbon atoms - is known to be a very good electrical conductor. As a result, graphene finds a multitude of applications in modern nanoelectronics. They range from highly efficient detectors for optical and wireless communications to transistors operating at very high speeds.

A constantly increasing demand for telecommunication bandwidth requires an ever faster operation of electronic devices, pushing their response times to be as short as a picosecond.

"The results of this study will help improve the performance of graphene-based nanoelectronic devices such as ultra-high speed transistors and photodetectors" says Professor Dmitry Turchinovich, who led the research at the MPI-P. In particular they show the way for breaking the terahertz operation speed barrier - i.e. one thousand billions of oscillations per second - for graphene transistors.

Media Contact

Natacha Bouvier
pr@mpip-mainz.mpg.de
49-613-137-9132

http://www.mpip-mainz.mpg.de/ 

Natacha Bouvier | EurekAlert!

More articles from Materials Sciences:

nachricht New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State

nachricht Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Fraunhofer ISE Pushes World Record for Multicrystalline Silicon Solar Cells to 22.3 Percent

25.09.2017 | Power and Electrical Engineering

Usher syndrome: Gene therapy restores hearing and balance

25.09.2017 | Health and Medicine

An international team of physicists a coherent amplification effect in laser excited dielectrics

25.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>