In my last post, I shared with you some of the excitement that several of my colleagues at Keithley experienced on a customer visit to the Condensed Matter Physics Lab at the University of Manchester. That visit coincided with the announcement that Drs. Geim and Novoselov had just been awarded the 2010 Nobel Prize in Physics. In their prize-winning research on graphene, a one-atom-thick layer of carbon atoms densely packed in a honeycomb crystal lattice, they used several Keithley instruments, including the Model 2182A nanovoltmeter and two Model 2400 SourceMeter instruments, to study this material’s field effect properties.
If millions of graphene layers were stacked one on top of the other, the resulting product would be graphite, but the two materials are fundamentally very different. Graphene has a number of unique physical, chemical, and electrical properties. Unlike graphite, graphene demonstrates not only an electric field effect but also ballistic electronic transport, which results in very high charge carrier mobilities of at least 60,000cm2/Vs. Such mobilities exceed that of silicon by at least a factor of 40, which makes graphene of particular interest to designers of the next generation of fast transistors. Also, much as with carbon nanotubes, the electronic bonds in graphene are very strong, which makes it an excellent structural material
In the wake of the Nobel Prize announcement, it seems like everyone is talking about the seemingly unlimited potential applications for graphene-based materials, which range from use in single-molecule gas detectors and solar cells to DNA sequencing and anti-bacterial materials. From an electronics manufacturing and test perspective, graphene has highly exploitable electrical properties. For example, graphene sheets have extremely low resistivity at room temperature. When electrons are confined in two-dimensional materials like graphene, it’s also possible to observe transport phenomena such as the quantum Hall effect. Of course, for Keithley and its customers, graphene’s most exciting possibilities are those associated with its potential for the development of new nanoscale devices like nanoribbons, transparent conducting electrodes, transistors, ICs, ultracapacitors, and many others.
So, what does the surging interest in graphene and its applications mean for Keithley and its research customers? First and foremost, it means that access to high accuracy, high sensitivity instruments and systems that are easy to use and flexible enough to adapt quickly to evolving requirements will be more crucial to researchers than ever before. To keep making progress on the graphene-based materials and devices that may one day replace the silicon-based ones we use now, scientists and researchers will need the support of their vendors to learn how to wring the maximum measurement sensitivity from their existing test hardware. Just as important, test hardware vendors and researchers must learn how to work together effectively to envision and then realize the next generation of high sensitivity instruments.
To learn more about some of the research on graphene now underway in labs around the world, visit the Google Scholar search engine at http://scholar.google.com/schhp?hl=en&tab=ws and enter “graphene” in the search box. Like me, I’m sure you’ll be stunned by the range of research now being conducted.
