New research conducted by the National Graphene Institute at The University of Manchester has developed a new method of synthesising 2D materials. These 2D materials are thought to be unobtainable by current technologies.
Since it’s discovery and isolation by Professor Sir Andre Geim and Professor Sin Kostya Novoselov from the University of Manchester, graphene research has become increasing popular.
As with other 2D materials, graphene has a 3D counterpart or bulk analogue. For example, graphene’s bulk analogue is graphite. The bulk analogue is often separated using mechanical exfoliation. This process consists of exfoliating the layers from each other until only a single layer remains.
There has been increasing interest in fabricating a synthetic 2D material that has no layer bulk analogue.
A team of researchers at the University of Manchester have been able to convert existing layered materials into a new covalent two-dimensional material. For example, mechanically exfoliated 2D selenide (InSe) is converted into atomically thin indium floride (InF3), which has a non-layered structure and therefore cannot be possibly obtained by exfoliation by a fluoridation process.
The newly obtained 2D indium fluoride is a semiconductor, exhibiting high optical transparency across the visible and infrared spectral ranges and could potentially use as a 2D glass.
Professor Rahul Nair is from the National Graphene Institute and Department of Chemical Engineering and Analytical Science. Professor Nair said: “Chemical modification of materials has proven to be a powerful tool for obtaining novel materials with desired and often unusual properties. There is still further work to be carried out to understand chemical conversion of 2D materials at the atomic scale, including effects of relative orientation and synergy between individual atomic layers on their chemical reactivity. We believe our work provides a significant advance in materials science and is a clear milestone in the development of artificial 2D materials.”
The leader of the experiment and the lead author of the study, Vishnu Sreepal, said: “Our work clearly demonstrates the possibility of creating artificial 2D covalent materials. The process is controllable, easy to execute and very effective. By precisely controlling the thickness of the starting 2D layers the thickness of the new covalent 2D materials can be controlled with an atomic-scale precision. The new covalent 2D material can also be controllably doped with dopants”.
“We also demonstrate the scalability of our approach by chemical conversion of large-area, thin InSe films into InF3 films.”