The materials found in the chips we rely on for nearly every aspect of daily life are fundamental to their performance. Silicon has been on top for many years, but its time in the spotlight is coming to an end. Already silicon carbide (SiC) chips promise revolutionary benefits for the automotive industry and clean energy applications. With limitless possibilities to explore, it’s no surprise companies in the chip industry spend billions every year to research new semiconductor materials.
Now, a team of researchers from Columbia University in New York has seemingly stumbled upon what could be one of the biggest breakthroughs in the history of chipmaking. The team published its findings, which focus on a new superatomic material called Re₆Se₈Cl₂, in the journal Science last month.
Some of the world’s greatest scientific discoveries happened by accident. Alexander Fleming stumbled upon penicillin while trying to stop bacteria from growing in his lab. The science behind the microwave was found thanks to a melted candy bar. Research into new refrigerants yielded Teflon, one of the most important manufacturing materials today.
When PhD student Jack Tulyag started studying Re₆Se₈Cl₂, a material made of rhenium, selenium, and chlorine, in the lab, it wasn’t with semiconductors in mind. Alongside his doctoral mentor, Tulyag was hoping to work on an experiment involving super-resolution microscopes. Instead, he and the other researchers found that Re₆Se₈Cl₂ acts as a semiconductor that speeds up electron movement with incredible efficiency.
In typical silicon, electrons move rapidly but erratically from place to place. The researchers liken it to the hare in Aesop’s famous fable—fast at first glance but not necessarily the most efficient choice. The new material stabilizes the electrons by weighing them down. Though it sounds counterproductive, this actually allows the electrons to travel faster by making their path more efficient. The proverbial tortoise.
Until now, researchers didn’t believe it was possible to make electrons move at the speeds Tulyag and his team measured. With Re₆Se₈Cl₂, they saw electrons travel micrometers in less than a nanosecond—roughly 100 to 1000 times faster than they can move in the fastest silicon chips.
That isn’t even the limit, though. Researchers believe that, given the right conditions, electron speed in Re₆Se₈Cl₂ could theoretically reach as much as one million times faster than silicon. Ironically, this is about the same difference as the gap in speed between modern computers and those from 20 years ago.
Any time a new semiconductor material is discovered, the chip industry takes notice. Unfortunately, nearly all of them are rejected for one reason or another. The Columbia University team’s Re₆Se₈Cl₂ isn’t without flaws.
For one, rhenium is incredibly rare. The alloy is primarily used as an additive to other metals to enhance their properties in extremely niche applications—such as x-ray machines and jet engine turbines. This means using Re₆Se₈Cl₂ to mass-produce semiconductors is likely out of the question for now.
Fortunately, the team believes a substitute material that gives electrons similar properties can be found. Columbia University assistant professor of chemistry Milan Delor said in an interview, “In terms of energy transport, Re₆Se₈Cl₂ is the best semiconductor we know of, at least so far. This is the only material in which sustained ballistic transport of excitons has been observed at room temperature. But now we can begin to predict what other materials that we simply hadn’t considered before might be capable of this behavior.”
For now, this breakthrough remains in the realm of research in the lab. One day, though, Re₆Se₈Cl or a similar material could reshape the landscape of the chip manufacturing industry. Requirements for today’s most advanced chips are already outpacing current materials. Chipmakers have gotten creative with technology like chiplet manufacturing to boost power and performance while they wait for a new material breakthrough to emerge. But that approach won’t last forever. Soon, new materials will be needed to truly advance next-gen semiconductors and ensure they are ready to meet the demands of high-powered technology like artificial intelligence and renewable energy.