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Molybdenite Moves From Potential Silicon Replacement to a Transistor Prototype

Combining the strengths of graphene and silicon could rise the abundant mineral molybdenite up the electronics ladder

2 min read
Molybdenite Moves From Potential Silicon Replacement to a Transistor Prototype

You may recall my coverage at the beginning of the year of work conducted by researchers at Ecole Polytechnique Federale de Lausanne’s (EPFL) Laboratory of Nanoscale Electronics and Structures (LANES) in using “the humble and abundant mineral molybdenite (MoS2) as an attractive alternative to silicon as a two-dimensional material (like graphene is) for replacing the three-dimensional silicon in transistors.”

Well, after publishing at the beginning of the year on the mere potential for molybdenite, the researchers have just published in the journal ACS Nano on their success at building a prototype transistor using the mineral.

In a press release prepared by EPFL, Andras Kis, the director of LANES, explains, “We have built an initial prototype, putting from two to six serial transistors in place, and shown that basic binary logic operations were possible, which proves that we can make a larger chip.”

With silicon it has not proven possible to reduce its thickness below two nanometers “because of the risk of initiating a chemical reaction that would oxidize the surface and compromise its electronic properties.” Molybdenite offers the ability to reduce the thickness of layers down to just three atoms. This translates into a reduction in size of nearly three times.

“The main advantage of MoS2 is that it allows us to reduce the size of transistors, and thus to further miniaturize them,” explains Kis.

It would also seem that molybdenite combines the 2D qualities of graphene with the inherent band gap of silicon.

The researchers still seem intent on downplaying molybdenite’s possible role as competitor to graphene, but I for one am not entirely convinced by the argument of it merely being a complement to graphene.

Nonetheless, back at the beginning of the year “applications that require thin transparent semiconductors, such as optoelectronics and energy harvesting” were highlighted, and now those applications have been somewhat expanded to include “…flexible electronics, such as eventually in the design of flexible sheets of chips.”

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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

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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