Graphene Electrodes Offer New Functionalities in Molecular Electronic Nanodevices
June 12, 2017 | University of BernEstimated reading time: 2 minutes
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 researchers performed the characterization of graphene-based molecular electronic devices at room-temperature and demonstrated that molecules covalently attached to mechanically robust graphene substrates are ideal candidates for next-generation molecular electronic devices. Alexander Rudnev, University of Bern
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. 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.
Suggested Items
SPEA Expands in Southeast Asia with New Subsidiary in Thailand
05/17/2024 | SPEASPEA, a global leader in automatic test equipment for the manufacturing of semiconductor, microelectronic and electronic devices, today announced the opening of its new subsidiary in Thailand. This expansion marks a significant step forward in SPEA's commitment to serving the growing Southeast Asian microchip and electronics market with leading-edge manufacturing machinery and equipment.
Indium Corporation to Showcase Sustainable Solutions for Power Electronics at PCIM
05/17/2024 | Indium CorporationAs one of the leading materials providers to the power electronics assembly industry, Indium Corporation® will proudly showcase a selection of innovative products at PCIM Europe, June 11-13, in Nuremberg, Germany.
Siemens, Foxconn Team Up to Optimize Forward-thinking Manufacturing
05/16/2024 | FoxconnSiemens AG, a leading technology company, and Hon Hai Technology Group (Foxconn), the world’s largest electronics manufacturer, have signed a memorandum of understanding (MoU) to drive digital transformation and sustainability in smart manufacturing platforms.
IPC Releases May 2024 Global Sentiment of the Electronics Supply Chain Report
05/16/2024 | IPCSentiment among electronics manufacturers fell this month, after hitting a new high in April. Despite the decline, sentiment remains historically high according to IPC’s May Sentiment of the Global Electronics Manufacturing Supply Chain Report.
Sypris Reports Q1 2024 Results; Revenue Up 10%
05/15/2024 | Sypris Solutions Inc.The Company’s first quarter 2024 consolidated revenue increased 10.1% to $35.6 million compared with the prior-year quarter, representing the 11th quarter of double-digit year-over-year growth during the past 12 quarterly periods.