Group tweaks semiconductor properties using nanoscale twist

Since the isolation of graphene in 2004, researchers have identified a multitude of 2D materials, each with specific properties and by stacking these thin crystals together, have created a number of artificial materials known as heterostructures.

A number of studies have demonstrated that it’s possible to further refine the properties of these heterostructures by adjusting the rotation – or twist angle – of adjacent crystals, but until now, these studies have been limited to graphene and hexagonal boron nitride.

A new study carried out by researchers at the University of Manchester’s National Graphene, has shown how that technique can also be used to tweak the properties of a class of atomically thin semiconductors known as transition metal dichalcogenides.

In a report published in the journal Nature Nanotechnology, the team describes that for small twist angles atomic lattices of transition metal adjust locally to form perfectly stacked bilayer islands, separated by grain boundaries which accumulates the resulting strain.