An international group of researchers from Europe has successfully synthesized a material known to be a cousin of the "wonder material" graphene, which has been attracting significant interest since its discovery in 2004.
Graphene is as flexible as rubber but a hundred times stronger than steel. It is also more conductive than copper and has excellent optical and heat conducting properties that could find potential uses in a wide array of industries which explain the tremendous attention it gets.
Unlike graphene which is composed of pure carbon atoms, the material called germanene is made up of one layer of germanium atoms but it also has remarkable optical and electrical properties seen to also open up new possibilities and applications. The two-dimensional material was proposed to be a substitute for graphene in 2009 but it has not gotten the same attention.
Following the successful synthesis of another 2D material silicene in 2012, a group of researchers embarked to find a way to synthesize germanene. For a study published in the Institute of Physics and German Physical Society's New Journal of Physics on Sept. 10, the researchers came up with a method that is similar to what is used for synthesizing silicene.
Under high temperature and under ultrahigh vacuum (UHV), the researchers deposited single germanium atoms into a substrate but instead of using silver as substrate, the researchers used gold and successfully created the elusive germanene.
"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," said study researcher Guy Le Lay, from the Aix-Marseille University in France. "This attempt failed, so I decided to switch to a gold substrate."
To ensure that the material they have created was indeed germanene, the researchers took spectroscopy measurements and made density functional theory (DFT) calculations to determine the material's electronic structure.
"We have succeeded in growing a 2D germanium sheet with a honeycomb appearance in scanning tunneling microscopy (STM) imaging on top of the Au surface," the researchers wrote. "We identify it as a germanene sheet after detailed synchrotron radiation spectroscopy measurements of the deposit (Ge 3d) and substrate (Au 4f) shallow core-levels."
Le Lay and colleagues also noted that another group of researchers who conducted a different and independent study reported that germanene can be synthesized using platinum as substrate. The researchers also said that their findings could have significant impact such as in optical applications and in the electronics industry.
