Scientists unveil new way to build 2D heterostructures
Scientists from Southampton and Singapore have unveiled a new fabrication technique for the ultra-clean manufacturing of 2D heterostructures which could be used in quantum technology and electronics.
The technique detailed in the paper 'Polymer-free van der Waals assembly of 2D material heterostructures using muscovite crystals' published in Nature Communications, was developed in collaboration between the Institute for Functional Intelligent Materials, National University of Singapore and the University of Southampton.
Current manufacturing methods to build 2D materials rely on sticky synthetic polymers to assemble the atomic layers.vHowever, these often leave behind microscopic residues that contaminate the tiny structures and disrupt the performance of electronic devices they are used in.
The team instead used the natural mineral muscovite, or mica, to stack the atomically thin materials together.
Their findings showed that replacing the messy polymers with mica makes the material atomically flat and offers better surfaces to precisely stack the atomic layers on top of each other.
Lead author Makars Šiškins, a Lecturer in Experimental Physics at the University of Southampton, said the new method makes assembly both cleaner and cheaper.
He added: “When 2D materials, like graphene and hexagonal boron nitride, are stacked into layered structures with controlled angle between the layers, they exhibit entirely new properties – from exotic superconductivity to tunable magnetism.
“Our new method allows us to precisely align the layers to create these complex structures that were previously too hard to make.
“This level of precision is vital for quantum material research, where even a tiny amount of contamination can obscure the results.”
Efforts to develop an ultra-clean fabrication method for 2D materials are viewed by scientists as a critical step toward the development of future nanoelectronics, and to eventually make microchips faster and more reliable, added Dr Šiškins.
Co-lead Alexey Berdyugin from the National University of Singapore said building atomic stacks without any contamination is a major challenge in nanotechnology.
He added: “Because mica is an inorganic crystal, rather than a soft polymer, it avoids many of the contamination issues that plague conventional methods.
“It also produces ultra-clean surfaces, allowing the electronic components to function at their full potential.
"It could help us finally unlock the full power of these advanced 2D heterostructure electronics, leading to major breakthroughs in both fundamental science and future quantum technology."
