While graphene has enormous potential, the project says concrete uses and applications for the ‘wonder material’ have yet to materialise and adds ‘the devil is in the detail’. The research team says it has managed to come to grips with some of these ‘devils’.
“Individual components based on graphene present outstanding characteristics,” said project leader Professor Thomas Pichler from the Electronic Properties of Materials Department at the University of Vienna. “However, the major breakthrough in its application as an integrated electronic component has not yet emerged. It has simply not been possible to use this material for established semiconductor technology in a way that can be replicated reliably.”
One of the biggest obstacles has been the lack of control of how graphene interacts with its environment at atomic level. As a result, says the team, it has been almost impossible to deploy the material in a predictable and targeted way. Even the interaction between graphene and the substrate to which it must be applied was only understood in part.
The team said it has gained some surprising insights. “We were able to demonstrate a correlation between charge transfer and mechanical strain in graphene for the first time,” said Prof Pichler. “This could be of major practical significance, as it means that entirely contactless measurement of internal strain in graphene based components may be possible.”
The team also managed to control, for the first time, the interface between graphene and traditional semiconductors like germanium at the atomic level. The researchers believe this as an important step towards making graphene based nanoelectronic components usable for semiconductor technology.
The project also produced ‘extensive samples’ of electronically insulated graphene for the experimental work. “We deliberately manipulated the electronic structure of graphene,” said Prof Pichler. “To do this, we replaced certain atoms in the graphene substrate with hydrogen or nitrogen atoms and measured the impact of this substitution.” Another approach adopted by Prof Pichler’s team involved intercalation, where layers of potassium, lithium or barium were inserted between the graphene and the substrate.
