Image: : Elizabeth Flores-Gomez Murray/Penn State
A team of Penn State and University of Tokyo researchers have recently combined one-dimensional van der Waals heterostructures in such a way that could lead to new, miniature electronics. A van den Waals heterostructure, according to Penn State, is a 2D stack of materials — combined similarly to LEGO blocks — that are held together via an attractive force between uncharged atoms.
So why is this newly discovered way of combining heterostructures so special? Previously, larger heterostructures were essentially “flat,” whereas these heterostructures can be “rolled” for a much smaller size.
“In this way, the 2D materials still contact each other in a desired vertical heterostructure sequence while one needs not to worry about their lateral edges, all rolled up, which is a big deal for making super-small devices.”
In a first for engineering, Penn State professor of engineering science and mechanics, Slava V. Rotkin, says, “It looks like a stack of 2D-layered materials that are rolled up in a perfect cylinder. In other words, if you roll up a sandwich, you keep all the good stuff in it where it should be and not moving around, but in this case you also make it a thin cylinder, very compact like a hot-dog or a long sushi roll. In this way, the 2D materials still contact each other in a desired vertical heterostructure sequence while one needs not to worry about their lateral edges, all rolled up, which is a big deal for making super-small devices."
The heterostructure cylinders are called hetero-nanotubes and could be used in what Rotkin calls “a new generation of both electronic and optoelectronic devices.” The hetero-nanotubes could be used as “extremely small” diodes with a high level of performance regardless of the tiny size. Diodes are used extensively in optoelectronics, such as photodetectors, solar cells, specialized circuits and light-emitting devices.