Nobel Prize in Chemistry for the discoverers of quantum dots

This Wednesday, the Royal Swedish Academy of Sciences awarded the Nobel Prize in Chemistry to Moungi G.. Bawendi, Louis E. Bruce and Alexei I. Ekimov, for the discovery and development of quantum dots. These are the smallest components of nanotechnology, which are used to illuminate computer screens, televisions and lamps based on QLED technology, but which also serve to guide surgeons when removing tumor tissue, among many other applications.

Everyone who studies chemistry learns that the properties of an element are governed by the number of electrons it has.. However, when matter is reduced to nanodimensions, quantum phenomena arise.. The winners of the 2023 Nobel Prize in Chemistry managed to produce particles so small that their properties are determined by quantum phenomena. These particles, called quantum dots, are of great importance in nanotechnology today.. These are artificial structures, built in the laboratory, that are capable of confining electrons in regions of tiny size, thousands of times smaller than the thickness of a human hair.

“Quantum dots have many fascinating and unusual properties. “It is important to note that they have different colors depending on their size,” says Johan Åqvist, president of the Nobel Committee for Chemistry.

Nanoscience seeks to study the phenomena that occur when materials are structured or patterned on a scale of less than about 100 nanometers (a nanometer is one billionth of a meter).. Nanotechnology is about taking advantage of these new properties to improve the performance of materials or to enable completely new applications.

Uses the tools of semiconductor physics, organic and inorganic chemistry, molecular biology and biotechnology. Applications range from modern electronics to industrial-scale catalysis, and from precision medicine to quantum technology.

In a sense, nanotechnology and nanoparticles have been used for many centuries. For example, a hair blackening formula originating from the Greco-Roman period has been shown to work by forming 5-nanometer lead sulfide nanocrystals within the hair cortex.. And the famous Roman Lycurgus cup has been shown to get its red color from gold particles contained in the size range of 5 to 60 nanometers.

Physicists had long known that, in theory, size-dependent quantum effects could arise in nanoparticles, but at that time it was almost impossible to reflect in nanodimensions. Therefore, few people believed that this knowledge could be put into practice.

However, in the early 1980s, Alexei Ekimov, born in the former USSR, and whose last position was chief scientist at Nanocrystals Technology Inc.. from New York, managed to create size-dependent quantum effects in colored glass. The color came from copper chloride nanoparticles. Ekimov showed that the size of the particles affected the color of the glass through quantum effects.

A few years later, American Louis Brus, a professor at Columbia University, was the first scientist in the world to demonstrate size-dependent quantum effects in particles floating freely in a fluid.

In 1993, Frenchman Moungi Bawendi, a professor at the Massachusetts Institute of Technology (MIT), revolutionized the chemical production of quantum dots, resulting in almost perfect particles.. This high quality was necessary so that they could be used in applications.

Quantum dots now illuminate computer monitors and television screens based on QLED technology. They also add nuances to the light of some LED lamps, and are used by biochemists and doctors to map biological tissue.

Therefore, explains the Royal Academy in its argument, quantum dots provide greater benefit to humanity.. Researchers believe that in the future they could contribute to flexible electronics, tiny sensors, thinner solar cells and encrypted quantum communication, so we have just begun to explore the potential of these tiny particles.

“It is a Nobel Prize that focuses on new materials that do not exist in nature and in which we design the properties. Each material has its own properties.. We make these materials very small, in the form of quantum dots. By controlling, for example, their size we control the light they emit, that is, we control their properties.. We make custom materials and this has opened the way for many other materials: quantum dots, nanowires, nanoplatelets…”, points out Iván Mora Seró, professor of Applied Physics at the Jaume I University of Castellón, to the Science Media Center (SMC ).