Nobel Prize in Chemistry awarded for quantum dot technology

This year’s Nobel Prize in Chemistry was awarded to scientists who worked decades to make your TV watching experience better, among other things. 

Moungi G. Bawendi, Louis E. Brus and Alexei I. Ekimov received the Nobel Prize in Chemistry for developing quantum dots, customizable nanoparticles which have different properties depending on their size. 

"Quantum dots have many fascinating and unusual properties. Importantly, they have different colors depending on their size," Chair of the Nobel Committee for Chemistry Johan Aqvist said. 

You’re likely looking at light emitted from quantum dots right now, as many modern computer monitors and televisions use quantum dots to create colors of each pixel. 

But that’s not all. The quantum dot technology is used in biomedical research to visualize molecules. In the future, quantum dots could be used in new areas of quantum communications, flexible electronics, miniature sensors as well as in improving solar cell technologies. 

What are quantum dots? 

Quantum dots are very tiny semiconductors around 2-10 nanometers in size — a few billionths of a meter. 

The size ratio of a quantum dot to a football is about the same as a football to planet Earth. 

Quantum dots all have the same structure — a crystal of metal oxide atoms. Simply changing their size can completely alter their properties. Smaller dots emit blue light and larger dots red and yellow. 

It’s not just their color that changes — but also their magnetic, electrical, thermal, catalytic properties. In other words, size matters. 

Quantum dot discovery

While the three chemists share the prize money worth 11 million Swedish crowns ($990,000, €948,000), they worked on quantum dots separately, and over several years.  

"Their incredible contributions to chemistry are reflected in their citation records: Bawendi shows an astonishing 100,000-plus citations in the Web of Science, and Brus 60,000-plus." David Pendlebury, Head of Research Analysis at the Institute for Scientific Information at British-American company Clarivate, told DW. 

The theory of quantum dots goes back more than a hundred years, but scientists found it near impossible to produce these materials. They needed to be able to make perfect crystals whose structures needed to be precise down to the atomic level. 

Nobel Prize winner Alexei Ekimov broke the deadlock and was the first to succeed in creating size-dependent quantum effects in glass. He did this by producing copper chlorine nanoparticles that displayed these quantum effects. 

Louis Brus observed the same effect for nanoparticles floating freely in a liquid solution.

For the dots to be useful, they need to be made with extreme control of size and surface. However, for a long time, no one thought these small particles could be produced.

Quantum dot production

Bawendi was awarded the Nobel Prize for doing exactly this — he invented the chemical method for creating quantum dots, allowing scientists to perfect the production of nanoparticles of very specific size and quality.

Asked by the Nobel Foundation website whether the call to inform him of his win woke him in the morning, Bawendi said it "absolutely" did. "I was sound asleep."

Louis Brus was Bawendi's post-doc supervisor. Bawendi calls him "a giant in the field."

"He's an amazing mentor," Bawendi said. "He's a true scholar, he's dedicated to science. I learned so much from him. He moulded me as a scientist."

Matthias Grotevent, a post-doc in Bawendi's lab, said the entire team was very happy to hear about his win.

"We all knew that Moungi [Bawendi] has been a potential candidate for his work and we were secretly rooting for him every year," Grotevent told DW via email. "However, there is so much excellent and ground-breaking research around the world, that we were still very much surprised that he won the Nobel Prize today." 

Grotevent also said that Bawendi's talents go beyond science. 

"As a team, we enjoy our annual ski trip excursions," he wrote. "Moungi is an excellent skier, too." 

Another prize for building molecules 

This is the third year in a row the Nobel Prize in Chemistry credits the synthesis or building of molecules. 

Carolyn R. Bertozzi, Morten Meidal, and K. Barry Sharpless and David MacMillan won the chemistry prize last year for the development of click chemistry, a novel tool for snapping molecules together.

There were no female scientists who won the award this year. The Nobel Prize in Chemistry has been awarded 115 times since 1901, to a total of 192 individuals. Only 8 women have received it so far.

The number of female Nobel laureates in the natural sciences is so low because, for a long time, women weren't allowed to study medicine, physics or chemistry. This had started changing by the time the Nobel prizes were established. But many still saw women as unfit for research, and their contribution to science received a lesser share of recognition than that of their male colleagues — a problem that many female scientists still encounter today. 

Nobel Prize announcements are set to continue with the literature prize on Thursday. Friday will see the announcement of the Nobel Peace Prize. The winners of the Nobel Prize in Economics will be announced on Monday, October 9, 2023.

Carla Bleiker contributed reporting.

Edited by: Sushmitha Ramakrishnan