The Royal Swedish Academy of Sciences has decided to award the Nobel Prize in Chemistry 2023 “for the discovery and synthesis of quantum dots”. This follows on from Digital Journal’s review of the physics prize (see: “Nobel Prize in Physics: Light capture studies capture the shortest of electron moments”).
The award has been given to Moungi G. Bawendi, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, Louis E. Brus, Columbia University, New York, NY, USA and Alexei I. Ekimov, Nanocrystals Technology Inc., New York, NY, USA.
What does this mean then, with the Nobel Prize in Chemistry 2023, being given for the discovery and further development of quantum dots? Today quantum dots are nanoparticles that manufacturers add to the layers of films, filters, glass and electronics — sometimes called the sandwich — that comprise display. These nanoparticles are so tiny that their size determines their properties.
These are the smallest components of nanotechnology and they spread their light from televisions and LED lamps. There are other important applications, including medicine where quantum dots help to guide surgeons when they remove tumour tissue, among many other surgical advances.
Within chemistry, an element’s properties are governed by how many electrons it has. However, when matter shrinks to nano-dimensions quantum phenomena arise; these are governed by the size of the matter.
The award winners succeeded in producing particles so small that their properties are determined by quantum phenomena. The particles, which are called quantum dots, are now of great importance in nanotechnology. Quantum dots have many fascinating and unusual properties. In addition, they have different colours depending on their size.
Physicists have theorised that size-dependent quantum effects could arise in nanoparticles, but this was once impossible to sculpt in nanodimensions. In the early 1980s, Alexei Ekimov succeeded in creating size-dependent quantum effects in coloured glass. The colour came from nanoparticles of copper chloride and Ekimov demonstrated that the particle size affected the colour of the glass via quantum effects.
Later, Louis Brus proved size-dependent quantum effects in particles floating freely in a fluid. Then, in 1993, Moungi Bawendi revolutionised the chemical production of quantum dots, resulting in almost perfect particles. This high quality was necessary for them to be utilised in applications.
Today, quantum dots now illuminate computer monitors and television screens based on QLED technology. They also add nuance to the light of some LED lamps, and biochemists and doctors use them to map biological tissue.
In the future quantum dots could contribute to flexible electronics, tiny sensors, thinner solar cells and encrypted quantum communication.
