Physicist discovers New 2D Material that could Upstage Graphene, advancing digital technology

The atoms in the new structure are arranged in a hexagonal pattern as in graphene, but that is where the similarity ends. The three elements forming the new material all have different sizes; the bonds connecting the atoms are also different. As a result, the sides of the hexagons formed by these atoms are unequal, unlike in graphene. Credit: Madhu Menon

Truly flat and extremely stable, the material is made up of light, inexpensive and earth abundant elements. The new material is made up of silicon, boron and nitrogen. “We used simulations to see if the bonds would break or disintegrate – it didn’t happen,” said Madhu Menon,UK Center for Computational Sciences. “We heated the material up to 1,000 degree Celsius and it still didn’t break.”

While graphene is touted as being the world’s strongest material with many unique properties, it has one downside: it is not a semiconductor and therefore disappoints in the digital technology industry. Subsequent search for new 2D semiconducting materials led researchers to a new class of 3-layer materials called transition-metal dichalcogenides (TMDCs). TMDCs are mostly semiconductors and can be made into digital processors with greater efficiency than anything possible with silicon. However, these are much bulkier than graphene and made of materials that are not necessarily earth abundant and inexpensive. So the team led by Menon studied different combinations of elements from the 1st and 2nd row of the Periodic Table. Although there are many ways to combine silicon, boron and nitrogen to form planar structures, only one arrangement resulted in a stable structure: a hexagonal.

The 3 elements forming the new material all have different sizes; the bonds connecting the atoms are also different. As a result, the sides of the hexagons formed by these atoms are unequal, unlike in graphene. The new material is metallic, but can be made semiconducting easily by attaching other elements on top of the silicon atoms. The presence of silicon also offers the exciting possibility of seamless integration with the current silicon-based technology, allowing the industry to slowly move away from silicon instead of eliminating it completely, all at once.

Besides creating an electronic band gap, attachment of other elements can also be used to selectively change the band gap values – a key advantage over graphene for solar energy conversion and electronics applications. “We are very anxious for this to be made in the lab,” Menon said. “The ultimate test of any theory is experimental verification, so the sooner the better!” Some of the properties, such as the ability to form various types of nanotubes, are discussed in the paper but Menon expects more to emerge with further study. http://uknow.uky.edu/content/university-kentucky-physicist-discovers-new-2d-material-could-upstage-graphene