"As it turns out, however, these 2D materials are only the first half of the story," says Tibor Grasser. "The materials have to be placed on the appropriate substrate, and an insulator layer is also needed on top of it - and this insulator also hast to be extremely thin and of extremely good quality, otherwise you have gained nothing from the 2D materials. It's like driving a Ferrari on muddy ground and wondering why you don't set a speed record."
A team at the TU Wien around Tibor Grasser and Yury Illarionov has therefore analysed how to solve this problem. "Silicon dioxide, which is normally used in industry as an insulator, is not suitable in this case," says Tibor Grasser. "It has a very disordered surface and many free, unsaturated bonds that interfere with the electronic properties in the 2D material."
It is better to look for a well-ordered structure: The team has already achieved excellent results with special crystals containing fluorine atoms. A transistor prototype with a calcium fluoride insulator has already provided convincing data, and other materials are still being analysed.
"New 2D materials are currently being discovered. That's nice, but with our results we want to show that this alone is not enough," says Tibor Grasser. "These new electrically conductive 2D materials must also be combined with new types of insulators. Only then can we really succeed in producing a new generation of efficient and powerful electronic components in miniature format".