Every chemist’s dream is to create new elements by mastering the intimacy of atoms. But quantum physics presented difficulties that presented strict, seemingly insurmountable limits. Until the idea and work of Moungi G. Bawendi (64 years old) from MIT in Cambridge USA, Louis E. Brus (82) from Columbia University of New York and Alexei I. Ekimov (78) did not produce nanoparticles that were like this were small that they broke through every barrier by creating “quantum dots,” also called artificial atoms, and controlling their properties. A laborious undertaking: That’s why the Swedish Academy of Sciences awarded them the 2023 Nobel Prize in Chemistry.
The three achieved the great result by working separately, although Bawuendi, the youngest, had been a student of Brus for a time. The Russian Ekimov had completed all of his studies in St. Petersburg and then flew to the USA to take on the role of chief scientist at the Nanocrystals Technoly laboratories in New York.
All three have been researching for around thirty years with the aim of obtaining nanoparticles that are smaller than those known in order to open up new possibilities. In the end, they succeeded with semiconductor materials such as cadmium and germanium selenide, which could be manufactured and managed in a dimension of less than 10 nanometers (millionths of a millimeter), controlling the quantum world they immersed themselves in by changing colors. That’s why they called them “quantum dots”. “The merit of the three was twofold: first they defined new knowledge and then they invented a simple and reliable method for obtaining microscopic particles, thereby opening the door to applications,” explains Paolo Milani, famous nanotechnologist and director of the Faculty of Physics of the State University of Milan, who had a valuable exchange with Bawendi on this extraordinary field of research. It was precisely the idea and the way in which it was implemented that motivated the academy to award the prize.
For the first time, detection was marked with a small yellow; a leak that forced the institution’s secretary general, Hans Ellegren, to say he was “deeply saddened” when the award was announced. This appears to be due to the “involuntary” publication of a statement by the Academy a few hours earlier, which was immediately picked up and distributed by the newspaper Dagens Nyheter and the magazine NyTeknik.
The practical results of quantum dots have already been achieved for several years and have been mass-produced by major manufacturers of monitors and television screens for at least five years. “These nanoparticles – says Milani – offer a wider range of colors, are cheaper, age slowly and therefore guarantee significant benefits.” However, their application goes much further and concerns LEDs, photovoltaic cells that make them more efficient, and also the medical sector. They are used as tracers in the human body and help surgeons to identify the point of intervention on a tumor more precisely. But we are only at the beginning and many more perspectives are emerging in the laboratories.