New technique can measure electronic properties of 2D materials

Electronic devices are set to become flexible, highly efficient and much smaller, following a breakthrough in measuring two-dimensional 'wonder' materials by researchers at the University of Warwick in the UK. Neil Wilson in the Department of Physics has developed a new technique for measuring the electronic structures of stacks of two-dimensional (2D) materials – flat, atomically thin, highly conductive and extremely strong materials – for the first time. The new technique is described in a paper in Science Advances.

Multiple stacked layers of 2D materials – known as heterostructures – can create highly efficient optoelectronic devices with ultrafast electrical charge. Such stacked layers can be used in nano-circuits and are stronger than the materials used in traditional circuits. Various heterostructures have been created using different 2D materials, and stacking different combinations of 2D materials creates new materials with new properties.

Wilson's technique measures the electronic properties of each layer in a stack, allowing researchers to establish the optimal structure for the fastest, most efficient transfer of electrical energy. The technique uses the photoelectric effect to directly measure the momentum of electrons within each layer and shows how this momentum changes when the layers are combined.

The ability to understand and quantify how 2D material heterostructures work – and to create optimal semiconductor structures – paves the way for the development of highly efficient nano-circuitry, and smaller, flexible, more wearable devices. Solar power could also be revolutionized by heterostructures, as the atomically-thin layers allow for strong absorption and efficient power conversion with a minimal amount of photovoltaic material.

"It is extremely exciting to be able to see, for the first time, how interactions between atomically-thin layers change their electronic structure," says Wilson. "This work also demonstrates the importance of an international approach to research; we would not have been able to achieve this outcome without our colleagues in the USA and Italy."

Wilson formulated the technique in collaboration with colleagues in the theory groups at the University of Warwick and the University of Cambridge in the UK, at the University of Washington in Seattle, and the Elettra Light Source, near Trieste in Italy. In addition, understanding how interactions between the atomic layers alter their electronic structure required the help of computational models developed by Nick Hine, also from Warwick's Department of Physics.

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