An RMIT collaboration with Japan has led to the discovery of a new form of science's latest wonder material, silicine, for use in a versatile array of applications in the manufacturing industry.
Silicon is best known for its use as a semiconductor in the fabrication of transistors, which amplify or switch electrical currents and are the backbone of many electronics.
Due to silicon's abundance in the environment and its semiconducting properties we rely on semiconductors made of Si for many of our everyday devices, such as mobile phones, computers, TVs and cars.
However, as the drive continues for the development of smaller and faster devices, the discovery of new materials such as silicene is imperative.
Silicene is a two-dimensional (2D) nanomaterial that is classified as a nanosheet, which has large lateral dimensions up to micrometres, but unfortunately its use in high technology applications is prevented because of its instability under ambient conditions.
Si-based nanomaterials could provide the solution to improve devices as they can be more easily integrated into current manufacturing processes that are already set up for silicon.
Recent RMIT breakthrough research led to the discovery of a new novel form of nanosilicon containing four-, five- and six- membered rings which display semiconducting properties while at the same time being resistant to oxidation.
Dr Michelle Spencer from the School of Science collaborated with researchers from the National Institute of Advanced Industrial Science and Technology and the Toyota Central R&D Laboratories in Japan to develop the two-dimensional nanomaterial which is called wavy bilayer silicene.
Spencer said that silicene is similar to graphene, in that it is an extremely thin material composed of atoms that are arranged in a honeycomb network showing unique properties highly suitable for applications in sensors, electronic devices and batteries.
Earlier findings by Spencer published in Nature's Scientific Reports reported that the full application of silicene is hindered not only by its instability under ambient conditions but also its high reactivity with oxygen.
"Our results gave some hints to help explain the conditions under which oxidation of silicene can occur," Spencer said.
"A number of factors, such as oxygen coverage or dose, as well as reaction temperature, significantly alter the degree of oxidation of silicene.
"This explains why control of the process is highly desirable in order to extend the potential range for the use of silicene in nanoscale devices under a variety of conditions, including metal/oxide semiconductor devices."
As a result of these findings, the team synthesised and modelled the bilayer silicenes.
Placing them between planar crystals of calcium fluoride and calcium disilicide made them highly resistant to oxidation, which opens up new avenues for it application.
Furthermore, the ability to modify the interfaces that sandwich the silicene enhances the applicability of the material.
The team's findings were published in the journal Nature Communications.
Dr Michelle Spencer has published 13 journal articles and 2 book chapters on silicene, including jointly editing the first book on this nanomaterial Silicene: Structure, Properties and Applications, Springer 2016 that reviews silicene's synthesis, unique properties and potential applications.
Story: Petra van Nieuwenhoven