New production method rubs 2D heterostructures up the right way

Researchers at the University of Exeter in the UK have developed a pioneering production method for heterostructure devices based on 2D materials such as graphene. Reported in a paper in Nature Communications, the new method is based on mechanical abrasion, whereby multilayer structures are formed by directly abrading different Van der Waals material powders directly on top of one another.

With this new abrasion method, the researchers saw sharp heterointerfaces emerge for certain heterostructure combinations. The results open the way for the creation of a wide range of heterointerface-based devices.

To demonstrate the applicability of this method, the researchers produced a multitude of different heterointerface-based functional devices, including resistors, capacitors, transistors, diodes and photovoltaics. They also demonstrated the use of these heterostructures for energy applications such as triboelectric nanogenerator devices and catalysts for the hydrogen evolution reaction.

"The production method is really simple, you can go from bare substrate to functional heterostructure device within about 10 minutes," said Darren Nutting from the University of Exeter and a co-author of the paper. "This is all without the need for complex growth conditions, 20 hours of ultra-sonication or messy liquid phase production.

"The method is applicable to any 2D material crystal, and can easily be automated to produce heterostructures of arbitrary size and complexity. This allows for the production of a plethora of device possibilities with superior performance to those created using more complex methods."

"The most interesting and surprising aspect of this work is that sharply defined heterointerfaces can be realised through direct abrasion, which we initially expected would lead to an intermixing of materials when directly abrading layer by layer," said Freddie Withers from the University of Exeter and lead author of the paper. "This observation allows for a large number of different devices to be realized through an extremely simple and low-cost fabrication process.

"We also found that the performance of our materials significantly outperform the performance of competitive scalable 2D materials production technologies. We think this is due to larger crystallite sizes and cleaner crystallite interfaces within our films. Considering the rudimentary development of the abrasive process thus far, it will be interesting to see how far we can push the performance levels."

This story is adapted from material from the University of Exeter, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.