Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Graphene electrodes offer new functionalities in molecular electronic nanodevices

12.06.2017

An international team of researchers led by the University of Bern and the National Physical Laboratory (NPL) has revealed a new way to tune the functionality of next-generation molecular electronic devices using graphene. The results could be exploited to develop smaller, higher-performance devices for use in a range of applications including molecular sensing, flexible electronics, and energy conversion and storage, as well as robust measurement setups for resistance standards.

The field of nanoscale molecular electronics aims to exploit individual molecules as the building blocks for electronic devices, to improve functionality and enable developers to achieve an unprecedented level of device miniaturization and control.


Molecules covalently attached to graphene are ideal candidates for electronic devices.

© Alexander Rudnev, University of Bern

The main obstacle hindering progress in this field is the absence of stable contacts between the molecules and metals used that can both operate at room temperature and provide reproducible results. Graphene possesses not only excellent mechanical stability, but also exceptionally high electronic and thermal conductive properties, making the emerging 2D material very attractive for a range of possible applications in molecular electronics.

A team of experimentalists from the University of Bern and theoreticians from NPL (UK) and the University of the Basque Country (UPV/EHU, Spain), with the help of collaborators from Chuo University (Japan), have demonstrated the stability of multi-layer graphene-based molecular electronic devices down to the single molecule limit.

The findings, reported in the journal Science Advances, represent a major step change in the development of graphene-based molecular electronics, with the reproducible properties of covalent contacts between molecules and graphene (even at room temperature) overcoming the limitations of current state-of-the-art technologies based on coinage metals.

Connecting single molecules

Adsorption of specific molecules on graphene-based electronic devices allows device functionality to be tuned, mainly by modifying its electrical resistance. However, it is difficult to relate overall device properties to the properties of the individual molecules adsorbed, since averaged quantities cannot identify possibly large variations across the graphene’s surface.

Dr Alexander Rudnev and Dr Veerabhadrarao Kaliginedi, from the Department of Chemistry and Biochemistry at the University of Bern, performed measurements of the electric current flowing though single molecules attached to graphite or multi-layered graphene electrodes using a unique low-noise experimental technique, which allowed them to resolve these molecule-to-molecule variations.

Guided by the theoretical calculations of Dr Ivan Rungger (NPL) and Dr Andrea Droghetti (UPV/EHU), they demonstrated that variations on the graphite surface are very small and that the nature of the chemical contact of a molecule to the top graphene layer dictates the functionality of single-molecule electronic devices.

"We find that by carefully designing the chemical contact of molecules to graphene-based materials, we can tune their functionality," said Dr Rungger. "Our single-molecule diodes showed that the rectification direction of electric current can be indeed switched by changing the nature of chemical contact of each molecule," added Dr Rudnev.

"We are confident that our findings represent a significant step towards the practical exploitation of molecular electronic devices, and we expect a significant change in the research field direction following our path of room-temperature stable chemical bonding," summarized Dr Kaliginedi. The findings will also help researchers working in electro-catalysis and energy conversion research design graphene/molecule interfaces in their experimental systems to improve the efficiency of the catalyst or device.

Publication details:
Alexander V. Rudnev, Veerabhadrarao Kaliginedi, Andrea Droghetti, Hiroaki Ozawa, Akiyoshi Kuzume, Masa-aki Haga, Peter Broekmann, Ivan Rungger: Stable anchoring chemistry for room temperature charge transport through graphite-molecule contacts, Science Advances, 9 June 2017, in press.

Contact:
Dr. Alexander Rudnev
Department of Chemistry and Biochemistry, University of Bern
Phone: +41 31 631 42 54
Email: alexander.rudnev@dcb.unibe.ch

Nathalie Matter | Universität Bern
Further information:
http://www.unibe.ch

More articles from Materials Sciences:

nachricht A materials scientist’s dream come true
21.08.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Novel sensors could enable smarter textiles
17.08.2018 | University of Delaware

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

Protein interaction helps Yersinia cause disease

21.08.2018 | Life Sciences

Biosensor allows real-time oxygen monitoring for 'organs-on-a-chip'

21.08.2018 | Medical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>