Microchips of the Future: Suitable Insulators are Still Missing

Until now, hexagonal boron nitride was considered the insulator of choice for miniaturised transistors. New investigations by TU Wien (Vienna) show: this may not be the way to go. For decades, there has been a trend in microelectronics towards ever smaller and more compact transistors. 2D materials such as graphene are seen as a beacon of hope here: they are the thinnest material layers that can possibly exist, consisting of only one or a few atomic layers. Nevertheless, they can conduct electrical currents - conventional silicon technology, on the other hand, no longer works properly if the layers become too thin. However, such materials are not used in a vacuum; they have to be combined with suitable insulators - in order to seal them off from unwanted environmental influences, and also in order to control the flow of current via the so-called field effect. Until now, hexagonal boron nitride (hBN) has frequently been used for this purpose as it forms an excellent environment for 2D materials.