New two-dimensional material could be more useful than graphene

Researchers from the University of Kentucky Center for Computational Sciences have developed a new one-atom thick material that could provide a light, stable and inexpensive alternative to the carbon allotrope graphine, with the added bonus of being a semiconductor.

As UK physicist Madhu Menon and colleagues from Germany and Greece reported Monday in Physical Review B, Rapid Communication, the new material is made from the abundant elements silicon, boron, and nitrogen, and unlike many other graphene alternatives, is extremely stable.

Menon’s team used theoretical computations to demonstrate that by combining these particular elements, they could potentially create a one-atom thick, 2D material with adjustable properties that would allow it to be used in applications that graphene is not suited for. They even showed that it could be heated to 1,000 degrees Celsius without its bonds disintegrating.

The study authors combined silicon, boron and nitrogen atoms in a hexagonal pattern similar to graphene in order to form a planar structure. However, each of the three elements have different sizes and different bonds connecting them, meaning that unlike graphene, the hexagons found in the new material are unequal, they explained in a statement.

Combining the best features of graphene and TMDCs

Touted as the strongest material on Earth, graphene is a carbon-allotrope that is about 100 times stronger than the most durable steel. However, it is not a semiconductor, and therefore its uses in digital technology are somewhat limited. Scientists searching for alternatives have created a new class of three-layer materials called transition-metal dichalcogenides (TMDCs).

TMDCs are semiconductors and can more easily be made into digital processors, but they tend to be bulkier than graphene and are made of less-abundant and more expensive materials. The UK-led team set out to find a better alternative that is light, inexpensive, made from readily available elements from the first two rows of the Periodic Table, and which was a semiconductor.

The material they came up with is metallic, but could become a semiconductor by attaching other elements on top of the silicon atoms. Also, since it contains silicon, it could easily be integrated into currently technology based on that element, which would allow tech companies to phase-out silicon slowly rather than being forced to eliminate it all at once. Furthermore, unlike silicine and other graphene alternatives, it is stable, has a flat surface and will remain 2D.

“We are very anxious for this to be made in the lab. The ultimate test of any theory is experimental verification, so the sooner the better!” Menon said in a statement. “This discovery opens a new chapter in material science by offering new opportunities for researchers to explore functional flexibility and new properties for new applications.”

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Image credit: Madhu Menon/University of Kentucky