Consumer electronic devices are made from materials that we have been using for more than 60 years, mainly silicon, germanium and copper. Why have semiconductor electronics become increasingly fast over this time?
I would argue that this is due to miniaturization, or the ability to stack an increasingly large number of transistors in a dense integrated circuit (microchip). Some may argue that we are starting to reach limits in that miniaturization, as thin films approach a thickness of just about 10 nanometers, or even lower.
These nearly two-dimensional (2D) materials could be used to build the next-generation electronics. However, as electronic materials like silicon are miniaturized, they become less energy efficient.
If you make the silicon film less than about 20 to 30 nanometers across, electrons will begin to bump into the edges of the film, leading to increased resistivity and more energy dissipation. This phenomenon has been known for decades and is described by a theory developed long ago by Klaus Fuchs (also famous as the "atomic spy" who supplied classified information about the Manhattan Project to the Soviet Union) and E. Helmut Sondheimer.
In a paper published in Physical Review Materials, I show that things get even worse than predicted by the Fuchs-Sondheimer theory as the thickness decreases below 10 nanometers, because a new effect sets in. This new effect is due to the quantum confinement of electrons.
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