A brilliant blue, a luminous green, a deep red – the range of colours Maksym Kovalenko presents in an array of test tubes in his lab is fascinating. But what is fascinating about the colours isn’t just that they shine so brightly, but also that they are the product of a remarkable idea that could set new standards in many areas.
Joël Mesot, President of ETH Zurich, classifies the chemistry professor’s achievements as: “Maksym Kovalenko’s work provides vital stimulus for both basic research and new applications.” That is why Kovalenko was awarded this year’s Rössler Prize at the ETH Foundation’s annual “Thanks Giving” event.
Brighter and clearer
The colours in the test tubes are produced by tiny, glowing nanocrystals known as quantum dots. What Kovalenko discovered a few years ago was that these quantum dots could also be manufactured from special semiconductor materials; known as metal halide perovskites. “Our quantum dots shine much brighter and and exhibit purest colors as compared to those known previously,” he explains with visible pride. “They’re also simpler to manufacture and easier to work with.”
The field of potential applications is broad: one obvious one is to use these materials to manufacture displays that are not only brighter and with better colour resolution than current models, but also less expensive and above all more energy efficient – definitely an important aspect considering how much energy today’s displays consume. These novel materials also hold interest for basic research: Kovalenko's group was able to show that these particles emit single photons in rapid succession, making them potentially appealing for applications in the field of quantum information processing.
A chemistry enthusiast even as a young boy
Now 37 years old, Kovalenko has long been passionate about chemistry. As he relates in our meeting, he discovered his fascination for this field when he was just 12 years old. A native of Ukraine, he first studied his favourite subject at Chernivtsi National University before going on to earn his doctorate at Johannes Kepler University in Linz. Following a postdoc position at the University of Chicago, he joined ETH Zurich as an assistant professor in 2011. Today he is an associate professor (with tenure) and heads the Functional Inorganic Materials Group in the Department of Chemistry and Applied Biosciences.
While most of his group works at ETH Zurich, about a quarter if his team is based at Empa in Dübendorf. “My group brings together scientists from a broad range of disciplines,” Kovalenko says. This breadth of expertise enables him to maintain control over the entire development chain, from synthesising the particles to designing prototypes for specific devices. This is an important key to his scientific success.
Inspired by Ralph Eichler
The bright quantum dots are certainly a spectacular part of Kovalenko’s research. Aside from this, though, he is working on a very different topic that has meanwhile also become very important to him: he and his group are looking for alternative materials for rechargeable batteries. Kovalenko is certain: “Demand for stationary energy storage options will soar in the coming years, and batteries will play a central role.” His goal is to manufacture powerful and inexpensive batteries from readily available materials to ensure that the future need for storage capacity can be met.
Incidentally, it was his first job interview at ETH Zurich that led him to this research field. Ralph Eichler, who was the ETH President at the time, inspired the young chemist to broaden his research scope to include this promising research area. And when Kovalenko talks about his idea to use graphite from the slag that results from steel production as a raw material for batteries, or minimally processed graphite ores from the nature, his great passion for unconventional research ideas once again fills the room.