Germanium was the first material used for transistors -- back in 1947 when AT&T Bell Labs invented them. Since then silicon has taken over as the semiconductor material of choice, even though germanium has witnessed a resurgence in recent years in everything from high-speed digital transceivers to analog optical detectors.
Other researchers have tried to fabricate germanium in atomically thin monolayers but have run into similar problems to fabricating monolayers of graphene--namely, the inability to grow perfectly crystalline lattices across an entire wafer. To solve the problem, Goldberger first wedged calcium atoms between separate germanane monolayers, thus easing their large-scale growth, then dissolved away the calcium and plugged the holes in the lattice with hydrogen atoms to prevent oxidation. As a result, the researchers were able to exfoliate (peel off) the germanane monolayers for testing.
Next the researchers aim to fabricate real devices with the new material as well as experiment with different termination molecules to act as dopants, which the team will then characterize for both electrical and optical properties. Currently, the material is stable up to 75 degrees Celsius (167 Fahrenheit) which the team also hopes to raise for use in a wider range of applications.
Assisting in the research was Goldberger's student, Elizabeth Bianco who recently won the Notre Dame Connect competition for her work on germanane. Also contributing were Ohio State researchers Sheneve Butler, Shishi Jiang, Oscar Restrepo and Wolfgang Windl. Funding was provided by the National Science Foundation, the Army Research Office and Ohio State University.
It is wonderful how unexpected discoveries like graphene open up new paradigms for exploration along parallel paths. I guess this helps explain why innovation (and evolution) seem to move in jumps rather than small continuous steps.
Isn' the electron mobility higher in germanium than in silicon? It will be intersting to see if this overcomes some of the negatives of germanium and makes a whole new class of transistor possible.
In my industry we really need a good THz transistor.
While a demonstration of a fabrication is clearly the first step, it sounds like there is a lot of work to be done. The statement that ... "germanane has the potential to be more easily grown using convention semiconductor fabrication equipment than graphane." suggests that it's not the time to throw in the towel on graphane.
No, not everything goes into the drain. you have venture into uncharted territories if you need to discover the next big thing. Putting a man on the moon didn't really result in much ROI of $100bn, other than I was the first one there. But the tech developed to achieve this feat is now used everywhere.
I think we are seeing a new era in semiconductor materials. Our ability to manipulate individual atoms in matrices opens a significant boost for three dimensional devices.
Star Trek had it right, we can use crystals for huge data storage applications.
David Patterson, known for his pioneering research that led to RAID, clusters and more, is part of a team at UC Berkeley that recently made its RISC-V processor architecture an open source hardware offering. We talk with Patterson and one of his colleagues behind the effort about the opportunities they see, what new kinds of designs they hope to enable and what it means for today’s commercial processor giants such as Intel, ARM and Imagination Technologies.