The Nobel Prize in Chemistry was awarded Wednesday to Moungi G. Bawendi, Louis E. Brus and Alexei I. Ekimov for being the pioneers of the nanoworld. The new laureates discovered and developed quantum dots, semiconductors made of particles so small that their electrons barely have room to breathe.
Semiconductors are crystals that help power our electronic devices. But while traditional crystals can be quite large at the molecular level, a quantum dot is made up of just a few thousand atoms squashed into a space just a few nanometers in diameter. The difference in size between a quantum dot and a soccer ball is about the same as the difference between a soccer ball and the Earth, the Nobel Foundation said.
“For a long time, no one would have believed that it would be possible to make particles this small,” Johan Aqvist, chairman of the Academy’s Nobel chemistry committee, said at the news conference announcing the 2023 laureates. the subject with five colorful vials lined up in front of him, which he said contained quantum dots in a liquid solution, he said: “But this year’s winners succeeded. »
News of the winners’ expected victory was reported earlier Wednesday morning in Swedish media, a very unusual leak this was later reported by Reuters And The Associated Press several hours before the official announcement from the Royal Swedish Academy of Sciences which awarded the prize.
Swedish media cited what they said was an email from the Academy that had been sent in error earlier. Reuters quoted Dr. Aqvist as saying: “This is a mistake on the part of the Royal Swedish Academy of Sciences.” He noted that the committee meeting was scheduled to begin at 9:30 a.m. local time (3:30 a.m. Eastern) and added, “so no decisions have been made yet.” Winners have not been selected.
Who are the winners?
Dr. Bawendi, born in 1961 in France, is a professor at the Massachusetts Institute of Technology and studied under Dr. Brus as a postdoctoral researcher.
Dr. Brus, born in 1943 in Cleveland, is professor emeritus at Columbia University.
Dr. Ekimov, born in 1945 in the former Soviet Union, was previously chief scientist at Nano crystals Technology, a company based in New York.
Why did the committee report receiving the award?
Electrons exist at fixed distances from the nucleus of an atom, with higher energy levels corresponding to greater distances. When atoms are energized, their electrons temporarily jump to higher distances and levels. When they fall, the electrons release the extra energy in the form of light.
A basic principle of quantum mechanics is that objects can behave like particles or like waves. The same goes for electrons: like other types of waves, they have a frequency linked to the color of the light they emit. Scientists have known since the 1930s that packing atoms into a small enough “container” could increase the frequency of their electrons and change the type of light the material absorbs or emits. This container is a crystal, called a quantum dot, because it triggers the wave behavior theorized by quantum mechanics.
But the idea remained theoretical, because scientists didn’t know how to squeeze a material to the point where such quantum effects could take over. In the 1970s, Dr. Ekimov began studying how the hue of colored glass could differ depending on the length of time it was heated. He find that when heated, copper chloride crystals form inside the glass. The smaller the crystals, the bluer the glass appears. Regardless, Dr. Brus discovered the same effect using cadmium sulfide crystals.
These were the first observations of a quantum effect that depended on the size rather than the elemental composition of the material. Yet scientists needed to figure out how to control this effect to harness it for real-world applications.
In the 1990s, Dr Bawendi Understood how to produce quantum dots of superb optical quality. They had to be made in solution “with careful control of their size and surface area,” Dr. Aqvist explained. Dr. Bawendi, he added, invented an ingenious chemical method “to do just that.” This breakthrough revolutionized technology in medicine and our daily electronics.
Quantum dots are now used to adjust the colors of LED lights and increase the resolution of television screens. They can also be used as fluorescent imaging tools in biomedical applications, such as identifying cancerous tissues. Quantum dots are expected to lead to advances in electronics, solar cells and encrypted quantum information.
How do their colleagues describe their work?
Judith Giordan, president of the American Chemical Society, described their work as “a magnificent example” of something that started as a theory, was perfected in university labs, and then brought to the world for useful applications.
“It’s not just esoteric science,” she said. “It’s meant to help people.”
According to Dr. Giordan, quantum dots enable the smallest pixel sizes that lead to ultra-high definition television screens. They also give us a wide range of color temperatures in the bulbs that light our homes. First research of the National Renewable Energy Laboratory says quantum dots could pave the way for doubling the efficiency of solar panels currently in use.
“People don’t know how these kinds of inventions happen,” said Jonathan Owens, a chemist at Columbia and Dr. Brus’s collaborator. “The Nobel Prize is obviously a great way to highlight this for society. »
He added that Dr. Brus’ discovery was a perfect example of “curiosity-driven work.”
William Tisdale, a chemical engineer at MIT, described Dr. Bawendi’s award-winning results as “a legendary paper in our field” and a “key advance, after which the quantum dot field exploded.”
What did the winners say about their victory?
Dr Bawendi said he was fast asleep when he received the call.
“I wasn’t sure it was true,” he said in an interview with the Nobel Foundation. “It’s quite an honor and quite a surprise.”
He added that this honor was complemented by sharing the award with his former mentor, Dr. Brus. “He shaped me as a scientist,” Dr. Bawendi said.
Before the announcement, Dr. Bawendi was scheduled to teach an introductory quantum mechanics class at 9 a.m. at MIT. But the lesson ultimately focused on his career leading to the Nobel Prize. Of the chaos of the day, he said: “I’m just going to let it go. »
Dr. Ekimov described feeling a little disoriented when he heard the news and said he was pleased that his work was being recognized. He remembers learning about quantum mechanics as a young student, two decades before the observations that led to the Nobel Prize. “It wasn’t surprising,” he said of the discovery, adding that they hoped to “provide experimental confirmation” to an already well-established theory.
Dr. Brus said his phone kept ringing while he tried to sleep. When he finally got it back, he learned from a Miami television station that he had won the Nobel Prize.
His first thoughts were of the many collaborators who helped make the discovery. “It’s a team effort,” he said. “It’s a great honor and it’s recognition for the field.”
Who won the Nobel Prize in Chemistry in 2022?
The prize went to Carolyn R. Bertozzi, Morten Meldal and K. Barry Sharpless to work on the chemistry of clicks.
Who else received a Nobel Prize in science this year?
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On Monday, the Physiology or Medicine prize was awarded to Katalin Kariko and Drew Weissman for chemical modification of messenger RNA. This modification led to the successful development of Covid-19 vaccines and saved millions of lives. Dr. Karikó is the 13th woman to win the Nobel Prize in this category.
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Tuesday, the physics prize was awarded to Pierre Agostini, Ferenc Krausz and Anne L’Huillier for their techniques shedding light on the subatomic domain of electrons. Dr. L’Huillier is the fifth woman to be chosen for a Nobel Prize in this category.
When will the other Nobel Prizes be announced?
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The Nobel Prize for Literature will be awarded Thursday by the Swedish Academy in Stockholm. Last year, Annie Ernaux received the award for his work dissecting the most humiliating, private and scandalous moments of his past with almost clinical precision.
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The Nobel Peace Prize will be awarded on Friday by the Norwegian Nobel Institute in Oslo. Last year, the price was shared by Memorial, a Russian organization; the Center for Civil Liberties in Ukraine; and Ales Bialiatski, a jailed Belarusian activist.
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Next week, the Nobel Memorial Prize in Economic Sciences will be awarded on Monday by the Royal Swedish Academy of Sciences in Stockholm. Last year, Ben S. Bernanke, Douglas W. Diamond and Philip H. Dybvig shared the prize, for his work which helped reshape the way the world understands the relationship between banks and financial crises.
All price announcements are broadcast live by the Nobel Prize organization.
