The Nobel Prize in Chemistry 2023: The Discovery and Synthesis of Quantum Dots
The Nobel Prize in Chemistry for 2023 has been awarded to three scientists for their groundbreaking work on the “discovery and synthesis of quantum dots.” In a recent interview on The Conversation Weekly podcast, we had the opportunity to speak with one of the laureates, renowned physical chemist Louis Brus, who played a pivotal role in understanding how the properties of these nanoparticles vary with their size. While initially taken by surprise, Brus is now receiving numerous congratulations and words of advice. Here are some highlights from the podcast:
The Accidental Discovery of Quantum Dots
During his time at Bell Labs in the 1980s, Brus stumbled upon quantum dots quite by accident. While studying solutions of semiconductor particles called colloids, he observed that the colors emitted by these solutions when illuminated by lasers were not consistent:
“On the first day, the spectrum was different. Second and third day, it was normal. There certainly was a surprise when I first saw this change in the spectrum. And so, I began to try to figure out what the heck was going on with that.”
Brus soon realized that the properties of the particles themselves were changing at extremely small sizes, leading to the discovery of quantum dots – nanoparticles that absorb and emit light at different wavelengths, with their colors dependent on their size.
Seeing the Unseeable: Quantum Dots
One might wonder how it is possible to see a quantum dot crystal, considering its minuscule size. Brus explains that optical microscopes are inadequate since quantum dots are smaller than the wavelength of light. However, specialized microscopes, such as electron microscopes, can be used for visualization. Another method involves arranging a series of glass flasks, each containing a solution of differently-sized quantum dots, which display their distinctive colors.
Interestingly, one of Brus’ fellow laureates, Alexei Ekimov, had actually observed quantum dots in colored glass. However, due to the Cold War and language barriers, Brus was unaware of Ekimov’s findings at the time. It was not until later, during the Glasnost period in the late 1980s, that Brus had the opportunity to meet Ekimov and his theoretical collaborator Sasha Efros.
The Advancement of Quantum Dot Applications
Initially, quantum dots posed challenges in terms of production and stability. However, another laureate, Moungi Bawendi, made significant advancements in this area in the 1990s. Brus highlights the importance of the scientific principles underlying quantum dots, which have been employed in various applications.
One notable application is biological imaging, where biochemists utilize quantum dots to map cells and organs. These nanoparticles have also been implemented in tumor detection and surgical guidance. Additionally, advancements in synthesizing quantum dots have led to their use in the display industry for creating computer and television displays that can generate any image by manipulating the three primary colors: red, green, and blue.
Brus acknowledges the risk associated with developing and investing in new technologies and credits companies like Samsung for their significant investments in quantum dot technology to manufacture displays and flat-panel TVs.
The Significance of Basic Research
Brus’ work exemplifies the importance of basic research, driven by curiosity and a desire to solve mysteries without specific industrial applications in mind. When asked what advice he would give to young chemists embarking on similar basic research, he emphasizes the need to select a problem that holds technological importance but lacks a fundamental understanding:
“You want to pick a problem where, if you are spectacularly successful and you actually discover something really interesting, it might have some application in the world.”
He also stresses the role of intuition in choosing research areas and the value of breaking down complex problems into basic steps for closer examination and understanding.
Life as a Nobel Laureate
Winning the Nobel Prize brings international recognition and certain responsibilities. Brus admits that his current position as a Nobel laureate holds special significance. While he still maintains an office at the university, he no longer leads a research group, opting to pass that responsibility on to younger researchers.
When it comes to the advice he received from previous laureates, Brus mentioned one crucial recommendation – learning to say no. With countless invitations and requests for participation in various events and speeches, it is essential to prioritize personal time and productivity. Additionally, he was encouraged to enjoy his time in Sweden, where the Nobel Prize award ceremony and associated festivities will take place.
Listen to the full interview with Louis Brus on The Conversation Weekly podcast, where academic experts share their fascinating discoveries and ongoing quests to answer profound questions.
