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Moungi Bawendi, Louis E. Bruce, and Alexei Ekimov Awarded 2023 Nobel Prize in Chemistry for the Discovery and Synthesis of Quantum Dots

  Before the 2023 Nobel Prize in Chemistry was officially released, there was a leak of the list.
  An email from the Royal Swedish Academy of Sciences titled “They sowed important seeds for nanotechnology” was accidentally leaked to the media more than four hours before the press conference.
  The “they” in the title of the email are three researchers from different countries. According to the list of 2023 Nobel Prize winners in Chemistry officially announced at 17:45 on October 4, Beijing time, they are Moungi G. Bawendi from France, Louis E. Bruce from the United States . Brus), and Alexey I. Ekimov of Russia.
  The three share the honor for their discovery and synthesis of quantum dots.
  Quantum dots are semiconductor nanocrystals, typically 2 to 10 nanometers in diameter. The size ratio of quantum dots to a football is roughly equivalent to the size ratio of a football to the Earth. However, it is small but significant.
  Many computer monitors, televisions, and LED lights use quantum dots to create the red, green, and blue (RGB) colors of each pixel. Additionally, quantum dots could guide surgeons in removing tumor tissue, among many other uses.
  ”Quantum dots have many fascinating and unusual properties. Importantly, their color depends on their size,” said Johan Aqvist, Chairman of the Nobel Committee for Chemistry.
It’s so small that it’s unbelievable. How did scientists discover it?

  The three laureates succeeded in creating particles so small that their properties are determined by quantum phenomena. Simply put, changing the size of quantum dots can completely change their properties, such as magnetic, electrical, thermal and catalytic properties. . In other words, the color of light emitted by quantum dots can be tuned by changing their size.
  At the Nobel Prize in Chemistry press conference, John Oquist explained through a picture display that each tiny particle is a tiny crystal, invisible to the naked eye. Nanoparticles composed of the same simple substance are placed in several small flasks. , the displayed colors are different. “This is the quantum effect. The smallest quantum dots emit blue light, and the larger ones emit yellow and red light, just because of the difference in size.” ”
  They discovered the possibility of making quantum dots.” This is 78-year-old Alek Reasons for winning the prizes for Sergei Ekimov, 80-year-old Louis Bruce and 62-year-old Mongi Bavandi.
  In the early 1980s, Alexei Ekimov succeeded in creating size-dependent quantum effects in colored glass derived from nanoparticles of copper chloride, which he published in In the scientific research journals of the former Soviet Union. Louis Bruce proved that due to quantum effects, the size of the particles alone can affect the color of the glass.
  In fact, before Ekimov and Bruce, scientists had long known that nanoparticles might possess theoretically unusual properties. In 1937, physicist Herbert Froehlich predicted that nanoparticles would behave differently from other particles. He explored the theoretical consequences of Schrödinger’s equation—that as particles become extremely small, there is less space for the electrons (both waves and particles) in the material, so they are squeezed together. Froelich realized that this would lead to dramatic changes in the material’s properties.
  When the researchers detected changes in the light absorbed by the particles, they knew that, in principle, they were now working with an entirely new material.
  Colleagues in the academic community have used mathematical tools to successfully predict many size-related quantum effects, but when trying to demonstrate quantum effects in the real world, scientists have encountered obstacles that are as difficult as carving a needle that is one millionth the size of a needle. Structure.
  For a long time, no one believed that such tiny particles could be produced.
  Although the scientific community made breakthroughs in the 1970s, the results were not satisfactory. For quantum dots to work, the size and surface of the nanoparticles in solution must be precisely controlled.
  It was not until 1993 that Mongi Bavandi revolutionized the chemical production of quantum dots, producing near-perfect particles whose high quality was closely related to their practical applications.
  Quantum dots are now an important part of the nanotechnology toolbox and are used in commercial products. Its luminescent properties are used in computers and televisions based on QLED technology, in whose screens the blue light is produced by energy-saving diodes that won the 2014 Nobel Prize in Physics. Using quantum dots to change the color of part of the blue light, converting it to red or green, makes it possible for TV screens to produce the required three primary colors.
  Likewise, quantum dots are used in some LED lights to modulate the luminescence of the diode. The light can be as bright as daylight or as soft as the warm glow of a warm light bulb.
  This property of quantum dots is also used in biochemistry and medicine. For example, biochemists can attach quantum dots to biological molecules to map cells and organs; doctors have begun to study the potential use of quantum dots to track tumor tissue in the body.
  Researchers believe that in the future, quantum dots could contribute to flexible electronics, tiny sensors, thin solar cells, and even encrypted quantum communications.
  It can be said that the achievements of this year’s three Chemistry Prize winners are an important milestone in the development of science and technology.
Three scientists lead different lives and write the same story together

  The three winners were born in three different countries: France, Russia and the United States.
  Ekimov was born in the Soviet Union in 1945. Since 1999, he has moved to the United States and serves as chief scientist at the American Nanocrystal Technology Company. Previously, as a Russian solid state physicist, Ekimov was attracted by the phenomenon that a single substance can produce different colors of glass.
  According to an article in the journal World Science, Ekimov heated molten glass to 500°C-700°C for periods ranging from one hour to 96 hours. Once the glass cooled and hardened, he examined it with X-rays. Scattered light showed that tiny crystals of copper chloride formed inside the glass, and that the manufacturing process affected the size of these particles. In some glass samples, the crystals are only about 2 nanometers, while in others they can reach 30 nanometers.
  Interestingly, it turns out that how well glass absorbs light is affected by the size of the crystal particles. The largest particles absorb light in the same way copper chloride normally absorbs, but the smaller the particles, the bluer the light they absorb. In 1981, Ekimov, a solid-state physicist, published the discovery in a Soviet scientific journal.

  At that time, Bruce, who was far away in the United States, did not see Ekimov’s paper. Two years later, in 1983, Bruce discovered size-dependent quantum effects in particles floating freely in solution. He and Ekimov got the same pattern—the smaller the particles, the bluer the light they absorbed.

  Bruce, who was born in the United States in 1943, has joined Columbia University in 1996 as a professor in the Department of Chemistry. Bruce became interested in chemistry and physics in high school, and after receiving his PhD in 1969, he joined the U.S. Naval Research Laboratory in Washington, D.C., as a lieutenant and served as a scientific staff officer.
  Four years later, Bruce left the Navy and joined the famous Bell Labs. The work that later discovered quantum dots was completed by Bruce during his time at Bell Labs. What is the envy of almost all scientists is that during his 23 years at Bell Labs, Bruce never wrote a research plan or budget. New ideas only need to be discussed informally with management before they can be implemented.
  After the list leak occurred, some media learned about the list of winners before the press conference. A radio station contacted Bruce immediately and informed him of the award. Bruce’s reaction was: “If this is confirmed to be true, It would be a great pleasure.” He also said, “I would have preferred to respond later in the morning. I’m still groggy, but it’s obviously a great honor.” Bawendi, this year’s third Nobel Prize winner in
  Chemistry , came to Bruce’s laboratory in 1988 and began to do postdoctoral work. There, they have been trying to improve the production methods of quantum dots in order to form good nanocrystals.
  This work had such a profound impact on Bavandi that he continued his efforts to produce higher-quality nanoparticles even after taking a position as research leader at the Massachusetts Institute of Technology (MIT). In the end, Bawendi created nearly perfect nanocrystals that produced unique quantum effects. This production method is so simple and easy to use that it is revolutionary – more and more chemists are beginning to use nanotechnology for research and are beginning to study the unique properties of quantum dots.
  Bawendi was born in France in 1961 and worked at MIT for 62 years. According to media reports, Bawendi only scored 20 points in his first college chemistry exam. “I had just entered Harvard at that time, and I planned to use my high school study methods to cope with college studies, which was ‘no method at all.'” Bavandi said, “I was scared, very depressed, and planned to drop out of school.
  ” In an interview, Bawundi was asked “Which one would he choose among friends, work, and sleep?” Bawundi said that he had never had enough sleep in his life. Bawendi imparted his experience of not sleeping to everyone: “If you like to work, you go to work.”
  According to media reports, after the news was announced, Bawendi said that he was “very surprised, in a dream, shocked and very honored “. He said by phone at the press conference: “I was woken up by the Swedish Academy. I slept soundly.” In a telephone interview on the same day, Bavandi said that he was surprised to win the award, “It was completely unexpected. Unexpectedly.” I feel honored for this.
  The three winners of this year’s Nobel Prize in Chemistry are well-deserved, each having contributed their own wisdom at different stages of the development of quantum dots. In fact, in recent years, there have been more and more cross-field and interdisciplinary studies in scientific research. Usually researchers from different majors cooperate extensively, or multiple teams in the same field compete for the same research direction.
  This year’s Nobel Prize in Science also highlights this trend. Without exception, more than one scientist won the award: the Physiology or Medicine Prize was shared by two scientific prizes, and the Physics Prize and Chemistry Prize were both won by three scientists.
  The Nobel Prize stipulates that the same prize can only be awarded to a maximum of three laureates. Perhaps, in the future, the Nobel Prize will change some rules with the times.

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