A team of European research experts at Aix-Marseille University utilised gold substrate to attain a new milestone by becoming one of the first groups to grow the 2-D nanomaterial germanene.
According to a study, germanene, a ‘cousin of graphene’, comprises of a simple single layer of germanium atoms and is expected to exhibit remarkable electrical and optical properties, that can be used in future electronics and its unique insulating characteristic increases the chance of it being utilised in quantum computing.
Germanene first proposed in 2009 remained cagey and since then, graphene has been blended with many 2-D materials to synthesize materials such as silicene which is made of silicon. Almost similar to silicene, the suggested method for synthesising germanene is to deposit individual germanium atoms onto a substrate under high temperatures and in an ultra-high vacuum.
The dubbed cousin of the ‘wonder material’ has been presented today, 10 September, in the Institute of Physics and German Physical Society’s New Journal of Physics under the title “Germanene: a novel two-dimensional germanium allotrope akin to graphene and silicene.”
Lead author Guy Le Lay, from Aix-Marseille University, said that graphene is not suitable to digital logic applications because it contains no gap, unlike silicene, and now germanene.
“There are also some claims that germanene could be a high temperature superconductor,” he said.
“Following our synthesis of graphene’s other cousin, silicene, we thought it natural to try and produce germanene in the same way, by despositing germanium onto a silver substrate,” Le Lay said.
“This attempt failed, so I decided to switch to a gold substrate.”
Post deposition of the germanium atoms onto a gold substrate, spectroscopy measurements, density functional theory (DFT) calculations, which investigated the electronic structure of the material, confirmed the material to be germanene.
A scanning tunnelling microscope bared the characteristic honeycomb structure of a 2D material.
With further development it might be feasible for germanene to be grown on thin gold films sitting on top of a flexible substrate, which would be an economical substitute than platinum and could pave the way to large scale germanene synthesis, said the researchers.
Lead author Le Lay appended, “We have provided compelling evidence of the birth of nearly flat germanene—a novel, synthetic germanium allotrope which does not exist in nature. It is a new cousin of graphene.
The synthesis of germanene is just the very beginning of a long quest. Indeed, success in the synthesis was not easy to achieve and quite demanding. A considerable amount of work is now needed to further characterize the electronic properties of the material.”
“An important aspect of our study is that we have increased the lego of 2-D materials that we can use to build a whole host of artificial solid materials with a wide range of differing properties,” said Professor Angel Rubio, co-author of the study from the University of the Basque Country.