A team of scientists from Columbia University, led by Chemistry Professor Milan Delor and Jack Tulyag, a Ph.D. student in Physical Chemistry, has discovered a new semiconductor that is much faster and more efficient than silicon, the material currently used in computer chips.
Unexpected Discovery of Superatomic
The new material, Re6Se8Cl2, is a “superatomic” material created by synthesizing superatoms and combining them with other elements, including rhenium, selenium, and chlorine. A superatom is a cluster of atoms that behaves like a single atom. Re6Se8Cl2 is
Re6Se8Cl2 was initially expected to be an insignificant conductor of electricity as researchers simply looked to test the resolution of the lab’s microscopes with it. However, when they tested the material, they discovered that it was actually the fastest conductor that they had ever seen.
Traditionally, silicon is a common material in semiconductor manufacturing based on its efficient and stable nature. Electrons in silicon can move very quickly, but they also scatter easily, which limits their mean free path and overall speed.
Re6Se8Cl2, on the other hand, is a superatomic semiconductor that uses excitons to carry charge. Excitons are bound pairs of an electron and a hole. They move more slowly than electrons in silicon, but they also scatter much less. This means they can travel faster overall than electrons in silicon.
In addition, Re6Se8Cl2 has a unique property called acoustic exciton-polarons. These are quasiparticles that are formed when excitons interact with acoustic phonons. Acoustic exciton-polarons move even slower than excitons, but they are also very stable and resistant to scattering. The acoustic exciton-polarons can travel very long distances without losing energy.
More Research Needed
If transistors made from Re6Se8Cl2 could be developed, they could transmit data hundreds or thousands of times faster than current silicon chips. However, Re6Se8Cl2 is still in the early stages of development, and more research is needed to make it practical for commercial use.
Despite this limitation, Re6Se8Cl2 is a breakthrough discovery in semiconductor research. The chemists plan to continue their work to find other superatomic materials that could be used to make even faster and more efficient computer chips.
The study’s results were published in Science.