Nobel Prize History
The Nobel Prize is the most prestigious award in the scientific world. It was created according to Mr. Alfred Nobel’s will to give a prize “to those who, during the preceding year, have conferred the greatest benefit to humankind” in physics, chemistry, physiology or medicine, literature, and peace.
A sixth prize would be later on created for economic sciences by the Swedish central bank, officially called the Prize in Economic Sciences, often better known as the Nobel Prize in Economics.
The decision of who to attribute the prize to belongs to multiple Swedish academic institutions.
Legacy Concerns
The decision to create the Nobel Prize came to Alfred Nobel after he read his own obituary, following a mistake by a French newspaper that misunderstood the news of his brother’s death. Titled “The Merchant of Death Is Dead”, the French article hammered Nobel for his invention of smokeless explosives, of which dynamite was the most famous one.
His inventions were very influential in shaping modern warfare, and Nobel purchased a massive iron and steel mill to turn it into a major armaments manufacturer. As he was first a chemist, engineer, and inventor, Nobel realized that he did not want his legacy to be one of a man remembered to have made a fortune over war and the death of others.
Nobel Prize
These days, Nobel’s Fortune is stored in a fund invested to generate income to finance the Nobel Foundation and the gold-plated green gold medal, diploma, and monetary award of 11 million SEK (around $1M) attributed to the winners.
Source: Britannica
Often, the Nobel Prize money is divided between several winners, especially in scientific fields where it is common for 2 or 3 leading figures to contribute together or in parallel to a groundbreaking discovery.
Over the years, the Nobel Prize has become THE scientific prize, trying to strike a balance between theoretical and very practical discoveries. It has rewarded achievements that built the foundations of the modern world, like radioactivity, antibiotics, X-rays, or PCR, as well as fundamental science, like the sun’s power source, the electron charge, atomic structure, or superfluidity.
Microscopic Colors
In everyday life, items have specific colors due to their intrinsic properties in how they interact with light. Sunlight contains a spectrum of colors, and when some colors are absorbed, this gives us different reflected colors.
Source: DataColors
These mechanisms do not work the same at the nanometer scale. Here, quantum effects changing the way electrons are arranged around an atom’s nucleus will change how a material absorbs light. In turn, this modifies its color.
More precisely, it derives from the application of the Schrödinger equation, which predicts how particles behave at the quantum scale, where they are both a wave and a particle.
In 1937, the physicist Herbert Fröhlich predicted that due to the Schrödinger equation, nanoparticles would behave differently from larger ones. Most importantly, when particles become extremely small, there is less space for the material’s electrons, so they are squeezed together.
Because the interaction of light with a material’s electrons determines its color, this predicted that quantum effects could change nanoparticles’ color depending on their size (and, therefore, how “squeezed” their electrons are).
Moving from theories in the 1930s to practice would take time and be truly achieved only in the 1980s and 1990s, with three different scientists progressively making it possible.
In 2023, they collectively received the Nobel Prize in Chemistry for their work that led to the discovery of so-called “quantum dots”.
Source: Nobel Prize
Today, quantum dots are used in medicine, screen, and QLED manufacturing, representing a $4 billion market in 2021.
They might become crucial in many more applications, from cancer detection with infrared quantum dots, to creating panchromatic solar systems or open new options in electronic manufacturing with nanophotonics.
From Ancient Glass To Quantum Physics
In the modern era, scientists rediscovered something glass makers had known since Antiquity: it is possible to create a colored glass of varying colors by adding impurities in the glass like silver, gold, and cadmium.
More intriguingly, the same added element could generate different colors depending on how the glass was heated and cooled.
Aleksey Yekimov, the first winner of this Nobel Prize, started analyzing colored glass with a light analysis tool used by the semiconductor industry. Using X-ray, he found that glass tinted with copper chloride produced with different heating times would have varying copper particle sizes, from 2nm to 30nm.
A fascinating phenomenon was that while large copper particles acted “normally,” the smaller the particles, the bluer the light that they absorbed.
Source: Nobel Prize
This was not the first time such a size-dependent quantum effect was observed, but this was the first time it was produced with a relatively simple manufacturing process, instead of extreme conditions like ultra-high vacuum and temperatures close to absolute zero.
Yekimov would publish his results in a Soviet scientific journal, and his discovery would not reach Western bloc scientists until the fall of the Soviet Union. So, in parallel, western scientists were also making discoveries that would lead to the invention of quantum dots.
Suspended Quantum Dots Particles
At Bell Labs in the USA, an incubator for at least 10 Nobel Prizes, Louis Brus studied how to use solar energy to produce chemical reactions. He used cadmium sulfide particles in a solution and produced as small as possible particles to maximize the reaction surface.
What he noticed is that the light absorption of these particles would change over time. After investigation he discovered that they were growing over time by agglomerating together smaller particles, moving from 4.5 nm to 12.5 nm.
The larger particle absorbed light the way you would expect cadmium sulphide to do. But smaller particles had an absorption that shifted towards blue.
Source: Nobel Prize
The particles in a colloidal suspension in a liquid used by Louis Brus were potentially a lot more useful than the one locked in glass from Yekimov, as they could be easier to mass-produce and refine.
However, the production method proved very inconsistent. Not only were the particles’ final sizes almost unpredictable, but the solutions contained a mixture of multiple sizes.
Far from being a pure product that could be used in other technologies and on an industrial scale, it was still mostly a scientific curiosity.
Mass Producing Quantum Dots
Moungi Bawendi was a post-doctoral student at Louis Brus’ laboratory in 1988. There, he experimented with all possible variables to create consistent quantum dots, testing the effects of different solvents, temperatures, and techniques. This made some progress but was still not enough for a consistent and replicable result.
Later, while working at MIT, he finally found a recipe that worked:
- They injected the solvent with exactly as much of the substances as was necessary to precisely saturate the solution.
- This led to tiny crystal “embryos” forming at the same time.
- The colder injection allowed to immediately stop the crystal formation.
- They then progressively rose the temperature, allowing for progressively bigger crystals to form.
- This step allowed the solvent to give the crystals a smooth and even surface, improving the resulting optical properties.
Source: Nobel Prize
This method resulted in an almost perfect quantum dot crystal. More importantly, it was easy to use, so more chemists could start producing quantum dots and investigating potential applications.
A Revolutionary New State Of Matter
What made quantum dots so impressive is that they completely changed how we can use the periodic table of elements.
In the Mendeleev period table, elements are classified according to their atomic mass and chemical properties. These properties are mostly driven by the behaviors of the electron clouds around each atom’s nuclei.
Source: Britannica
By modifying the way an element’s electrons behave, quantum dots essentially gave a whole new dimension to the period table of elements. So the discovery and mass production of quantum dots is akin to the discovery of entirely new materials, with new electric and chemical properties.
This is a little reminiscent of other materials with unique properties, like nanotubes or the growing arrays of potentially civilization-changing 2D materials like graphene, borophene, and goldene.
Source: Ossila
Quantum Dots Applications
QLED
One of the largest current applications of quantum dots is QLED technology (Quantum dot LED).
In it, quantum dots change blue light into red or green, allowing the creation of screens with vivid colors using only one light source (the blue light is emitted by blue light LED, a discovery rewarded by a Nobel Prize in 2014, which we previously covered).
Quantum dots are also used to improve the light from LEDs by making the colder light into a more pleasant color.
Optical Signal
While most quantum dots today are using the solvent-based solution from Brus & Bawendi, embedded crystals discovered by Yekimov are still used, for example for signal amplification in fiber-optic communication systems.
Quantum dots produced by another method were discovered later (Stranski-Krastanov growth method) and are, for example, used in quantum dot lasers for optical communication.
Biochemistry
Due to their very unique and distinctive colors, quantum dots can be used as markers to track down things at the microscopic level.
One such application is for biochemists to attach quantum dots to biomolecules like viruses, DNA, or proteins, allowing them to track their movement and accumulation with a simple fluorescence microscope.
Source: Sigma Aldrich
Medicine
Because of their imaging potential, quantum dots can be used to track tumor tissue in the body by tying the quantum dots to molecules binding to cancer cells only.
Source: Degruyter
An emerging field of medicine using quantum dots and their ability to “spot” cancer is phototherapy. In it, doctors used the quantum dots to absorb light and produce either heat or reactive chemicals causing the death of surrounding tumor cells.
However, more research is required to routinely use quantum dots in medicine, as they can cause unwanted side effects, like damaging healthy cells, degrading or agglomerating in the body, and being poorly eliminated by the kidneys.
Chemistry Catalysts
The discovery of quantum dots started with the search by Louis Brus for better catalysts, compounds that can speed up or make possible otherwise slow chemical reactions.
And it might still be one key application of quantum dots, thanks to their ability to absorb light to power chemical reactions that would not happen otherwise.
Source: ACS
This could be used to split water in hydrogen, reduce CO2 into hydrocarbon compounds, and boost other chemical reactions.
Carbon nanotubes, fullerene, and graphene are carbon quantum dots frequently used as photocatalysts due to their advanced properties like water solubility, tunable photoluminescence, low biological toxicity, and ease of surface functionalization.
Quantum dots: catalysis applications
Energy
Because quantum dots are ultimately a semiconductor material, with variable band gaps depending on their size, they have a strong potential for application in creating better solar cells.
Source: Degruyter
The main advantage quantum dots would bring to solar cells is that they could widen the solar spectrum that can be converted into energy (silicon solar cells only convert into power the highest energy photons, “missing” 70-75% of the Sun’s energy).
So, while conventional solar cells are likely to progress to a maximum of 30-35% conversion efficiency, quantum dots solar cells have a theoretical maximum of 66% efficiency (see below about QD Solar).
Quantum Computers
In the race to create a bigger and larger quantum computers (which we investigated in “The Current State of Quantum Computing“), quantum dots might be a valuable tool.
They could be used as the base component of the computer, the Qubit. Or they could form parts of the system used to localize and detect single spin, as well as being a good source of single photons.
Because quantum dot production is now well understood and relatively cheap, designs relying on them could help bring quantum computers to a scale of mass production and lower their price tag.
Investing In Quantum Dots & Nanotech
QLED is currently the largest market for quantum dots, with the giant Korean conglomerate Samsung (its branch Samsung Electronics – SSNLF) the leader of the market.
However, quantum dots themselves are a relatively small part of the overall business, with the company also active in all sorts of semiconductors (memory, chips, sensors, 5G, etc.). Hence, quantum dots are not really the core of the business.
You can invest in quantum dots & nanotech companies through many brokers, and you can find here, on securities.io, our recommendations for the best brokers in the USA, Canada, Australia, the UK, as well as many other countries.
If you are not interested in picking quantum dots & nanotech companies, you can also look into nanotechnology ETFs like the ProShares Nanotechnology ETF (TINY) or the Direxion Nanotechnology ETF (TYNE) which will provide a more diversified exposure to capitalize on quantum dots & nanotech stocks.
Or you can look at our list of the “Top 10 Nanotechnology Stocks”.
Quantum Dots & Nanotech Companies
1. Nanoco Group (NANO.l)
Listed on the London Stock Exchange under the NANO ticker, Nanoco specializes in the development and manufacture of quantum dots and other nanomaterials.
The company is a pioneer in cadmium-free quantum dots, with 375 patents and a license partnership with Samsung. This closed a 2-year litigation with Samsung from 2021-2023 over IP rights, which ultimately resulted in Nanoco receiving $90M from Samsung.
So it can provide a way to invest in quantum dots that is similar to Samsung, but with a stronger focus on this technology in particular.
While the company is mostly focused on LED applications (OLED, μLEDs, QD-EL), it is also investigating new markets, like, for example, security tagging for bills.
Source: Nanoco
Another sector the company is investing in is infrared quantum dots, with Heatwave. It should allow for very precise Infrared sensors. Among the possible applications are:
- Biometric facial recognition.
- Optical diagnostic (measurements of O2 levels, bilirubin, and glucose).
- LIDAR
- Night vision.
The company is only starting to commercialize its technology with two commercial production orders in 2024.
The cadmium-free technology of Nanoco quantum dots could make a very solid application for medical and biotech applications, which are usually less welcoming of heavy metal-based quantum dots.
2. QD Solar / SunDensity Canada
QD Solar, a developer of quantum dots solar panels and a leader in this technology, was recently bought by SunDensity Canada, a solar panel producer.
This acquisition might be a game-changer in solar technology.
On one hand, QD solar technology allows for higher efficiency through the use of quantum dots. This allows the panel to utilize infrared wavelength to produce electricity, with perovskite used to absorb the high-energy photons of the visible spectrum.
Source: QD Solar
On the other hand, SunDensity technology uses special nano-coatings to protect solar panels from UV-induced degradation, instead of converting UV light into more electricity.
QD Solar’s “active approach” is achieved through the addition of a perovskite layer in tandem with a silicon PV cell. SunDensity’s “passive approach” involves coatings that efficiently shift the energy of incident sunlight into a more usable range for solar panels to absorb.
The technologies are complementary with the potential to achieve more than 40% module efficiency when combined.
Yahoo Finance
So the combination of using in the same solar panel perovskite (high energy visible photons), nano-coatings (UV light), and quantum dots (infrared photons) could make for the maximum efficiency possible reachable by a solar panel.
Source: QD Solar
The perspective of upcoming 40% efficiency solar panels and even more later could be a game changer for the industry.
High-efficiency and more durable solar panels could especially be valuable for demanding applications like space-based solar power.