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Transistor Made From Silicene for First Time

Silicene matches what models predicted but it's still not ready for the world outside a lab

2 min read
Transistor Made From Silicene for First Time
Image: The University of Texas at Austin

Ever since silicene—a one-atom-thick layer of silicon—was first predicted in computer models a decade before graphene was first synthesized in 2004, it’s been on a roller coaster ride. It’s gone from being considered the next big thing to being thought of as an impossibility outside of computer models.

Drawing on an increasing amount of recent research demonstrating that silicene can survive—for at least a little while—outside the virtual world of computer models, researchers at the University of Texas at Austin have taken it all a step further by demonstrating a method for fabricating a field-effect transistor out of silicene. The device reportedly lives up to the switching speeds that had been promised in the computer models. Most importantly, this research marks the first time that anyone has been able to fabricate a transistor out of silicene.

In research published in the journal Nature Nanotechnology, the Texas researchers grew their silicene on a thin film of silver and capped it with aluminum oxide. Adding this light coat of protective oxide to create a protective shell—what’s known in the business as passivation—has recently proven effective in protecting graphene devices.

The researchers took the encapsulated silicene and placed it on a silicon dioxide wafer with the silver side up. They then put patterns into the silver side that would allow for contacts to be made so it could operate as a transistor.

The device was not tested in the open air, but it at least remained stable in vacuum conditions. Of course, this situation is not practical for real-world applications, but the researchers feel that this marks an important step towards realizing commercially viable silicene-based transistors.

The experimental research does confirm some of the theories that had been based solely on computer models. It demonstrated that silicene has electrical properties similar to those of graphene, including allowing electrons to travel through the material without any barriers.

While this research provides some confirmation of silicene’s attractive electronic properties, the research falls somewhat short of supporting the notion that because silicene is made from silicon it will be easier for the electronics industry to adopt. Silicene may be a one-atom-thick relative of silicon, which the electronics industry has characterized for the last half-century, but this research doesn’t seem to indicate that it has become any more friendly to large-scale manufacturing than its more mature cousin.

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The Transistor at 75

The past, present, and future of the modern world’s most important invention

2 min read
A photo of a birthday cake with 75 written on it.
Lisa Sheehan
LightGreen

Seventy-five years is a long time. It’s so long that most of us don’t remember a time before the transistor, and long enough for many engineers to have devoted entire careers to its use and development. In honor of this most important of technological achievements, this issue’s package of articles explores the transistor’s historical journey and potential future.

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