Single-Molecule Graphene Switches Bring Minute Electronic Devices a Step Closer
November 28, 2016 | Imperial College LondonEstimated reading time: 2 minutes
Graphene is a material made of a single sheet of carbon atoms in a honeycomb arrangement. Because of its unique electrical conductivity, graphene has the potential to be a base for electronic devices that are only nanometres (billionths of a metre) in size.
In order to tune sheets of graphene to be useful in different situations, other organic molecules are attached to the sheet, and these molecules must interact with the graphene sheet in predictable ways.
For example, if the electric charge of molecules could be controlled, then they could be used as molecular ‘switches’. Switches are important in electronic devices that store information, such as hard drives, where the sequence of ‘on’ or ‘off’ positions of the switch encodes information, in a similar way to the 1s and 0s of digital information.
Researchers have experimented with single molecules on graphene sheets, but it has been difficult to interpret the results and therefore to design devices that take advantage of the interactions between the sheets and molecules.
Now, a team led by Prof Mike Crommie from the University of California, Berkeley and including researchers from Imperial College London have discovered how to control one property – the charge state – of single organic molecules attached to graphene sheets.
Their results are published today in the journal Nature Communications ("Tuning charge and correlation effects for a single molecule on a graphene device").
Ultra-small switch
The team placed a molecule of tetrafluorotetracyanoquinodimethane (F4-TCNQ) on a graphene sheet and increased the electron density of the graphene using an electric field. Using techniques called scanning tunnelling spectroscopy and atomic force microscopy, they found the graphene donates some of its electrons to the organic F4-TCNQ molecule, changing its charge state in a predictable way.
This insight could allow scientists to design tiny graphene-based electronic devices. Dr Johannes Lischner, from the Department of Materials at Imperial, helped develop some of the theory behind the system. He said: “A molecule with a controllable charge state can act as an ultra-small switch, which is a fundamental building block of electronic devices.
“Such a switch could be used to store information, similarly to flash memory used in USB sticks. Alternatively, in a biological sensor you could theoretically use switchable molecules to help detect the presence of other molecules, such as cancer cells.”
The team are now expanding their method to investigate pairs of molecules and assemblies of small numbers of molecules on graphene sheets, as well as looking at ways to anchor single molecules to the graphene in order to simplify the fabrication of new devices.
Suggested Items
Book Excerpt: The Printed Circuit Assembler’s Guide to... Factory Analytics
04/24/2024 | I-Connect007 Editorial TeamIn our fast-changing, deeply competitive, and margin-tight industry, factory analytics can be the key to unlocking untapped improvements to guarantee a thriving business. On top of that, electronics manufacturers are facing a tremendous burden to do more with less. If you don't already have a copy of this book, what follows is an excerpt from the introduction chapter of 'The Printed Circuit Assembler’s Guide to... Factory Analytics: Unlocking Efficiency Through Data Insights' to whet your appetite.
Elevating PCB Design Engineering With IPC Programs
04/24/2024 | Cory Blaylock, IPCIn a monumental stride for the electronics manufacturing industry, IPC has successfully championed the recognition of the PCB Design Engineer as an official occupation by the U.S. Department of Labor (DOL). This pivotal achievement not only underscores the critical role of PCB design engineers within the technology landscape, but also marks the beginning of a transformative journey toward nurturing a robust, skilled workforce ready to propel our industry into the future.
Winner of The Science Show Rakett 69 Receives Incap Scholarship
04/24/2024 | IncapThe winner of the Rakett 69 science show, Andri Türkson, who stood out as an electronics enthusiast, received a scholarship from Incap Estonia, along with an internship opportunity in Saaremaa.
Alternative Manufacturing Inc. Awarded QML Requalification to IPC J-STD-001 and IPC-A-610
04/24/2024 | IPCIPC's Validation Services Program has awarded an IPC J-STD-001 and IPC-A-610 Qualified Manufacturers Listing (QML) requalification to Alternative Manufacturing Inc (AMI).
Boeing's Janene Stinson Earns IPC Excellence in Education Award at IPC APEX EXPO 2024
04/22/2024 | IPCThe IPC Excellence in Education award was presented to Janene Stinson, Boeing, at IPC APEX EXPO 2024 in Anaheim, California, in recognition of her significant contributions to workforce development and leadership.