TODAY -

Quantum Dots and Chemistry Nobel Prize 2023
- From a Layman's Perspective -

Prof Homendra Naorem *



The Royal Swedish Academy of Sciences, founded in 1739, has in clock like regularity announced that the Nobel Prize in Chemistry for 2023 would be awarded to Moungi G. Bawendi, MIT, USA, Louis E. Brus, Columbia University, USA and Alexei I. Ekimov, Nanocrystals Technology Inc., USA for the discovery and synthesis of quantum dots - a class of nanoparticles so tiny that their size determines their properties.

Though the word 'Quantum' is well accepted among the general public, quantum dots unlike dot com (.com as in IT) are rarely heard of, let alone the terminologies like quantum theory, quantum effects, quantum world, etc. What exactly are these quantum things and their significance to a layman?

The 20th century perhaps dawned with the quantum theory and quantum world - a world made of electrons, protons, neutrons and other smaller constituents where every small bit of action is given by the product of its energy and time so long as the product is less than the Planck's constant. Initially there were very few takers of the quantum theory until almost all the then unexplained phenomena like black body radiation, photo electric effect, absorption and emission of light, heat capacity of solids, etc. were one by one rationalized in the light of the quantum theory.

The quantum world operates at atomic or even smaller scales and at this scale things do not behave the same as the objects on the scale that we can see and perceive which makes the quantum theory defying the common sense!

For example, common sense implies that an unarmed person kept confined in a room with strong iron walls will never be found outside of the room unless the person is physically released, but if an electron is confined in a similar room or box (of atomic scales, of course), there is a finite probability that it can be found outside the box anytime (quantum tunnelling)!

Despite so many unconceivable results and predictions, quantum theory continues to flourish giving birth to many new discoveries, inventions, technologies, etc. Quantum theory largely operates on the concept of 'probability' rather than 'certainty' which led Einstein at later stages sceptical of the theory as reflected in his infamous quote, 'God does not play dice'.

The smallest unit of matter called molecules are made of atoms whose constituents are electrons, protons, neutrons, etc. known as the elementary or the quantum particles which are best understood through the prism of quantum theory. All the matter and that everything we see and experience emerges from these invisible quantum particles in their infinitesimal realm with all the mystifying effects in its weirdness.

What happens when the size of the matter becomes smaller? Will they continue to behave the same or contrarily? The size (radius) of atom is about 0.1 nm (1 nm=10-9m) and the nucleus about 10-6 nm. When the size of the matter is reduced to less than 100 nm, matters begin to show unexpected properties giving birth to nanoparticles, nanomaterial and nanotechnologies. The unique properties of the nanomaterials or nanoparticles are generally attributed to their size and more importantly to their high surface area to volume ratio.

Properties of atoms are largely dictated by the electrons present in their outermost orbital - the so called the valence electrons - which roughly is the principle on which the modern periodic table is based on. When these electrons under the influence of the nuclear potential are confined within a tiny space, they start behaving abnormally giving rise to what is known as the quantum effects like restricted or quantized motions, uncertainty in their position and momentum, etc.

The quantum effects exhibited by the quantum particles like electrons is perhaps due to its forced confinement within the tiny space with boundary conditions (restrictions) rather than the size alone since electrons would begin to behave normally once released (ionized) from the confinement. Like a person kept under house arrest or solitary confinement beginning to behave differently like a man possessed, electrons when confined within the nuclear potential also begin to behave abnormally, if you like.

Reducing the space available for the electronic motions to atomic scales increases the energy gap between its quantized energy states or, in other words, as the size decreases the energy gap will become wider requiring more energy for the electron to jump around resulting into absorption or emission of light at higher frequency and hence, a change in its color - an effect known as blue shift.

The optical and other luminescent properties of the matter will thus become size dependent sowing the seeds of Quantum Dots! Quantum dots are nanoparticles of single nm dimension usually made from semiconducting materials such as metal sulphides or halides which are capable of showing profound quantum effects with its electrons confined inside the dot (the nanomaterial) through blue shift effects.

It should, therefore, be possible to develop tiny nanomaterials whose optical and electrical properties can be tuned by tuning its size. But it had largely remained at conceptual level until the development of such materials. Who else can develop such materials better than a Chemist!

In 1981 the Russian physicist Ekimov reported in a Soviet scientific journal that the color of the glass when tinted with copper chloride can be changed simply by changing the size of the tiny crystals of copper chloride tinted in the glass by heating it at different temperatures. The results were just unbelievable - the color of the glass simply dependent on the size of the particle in it or the same particle giving different color - a clear case of split personality! This had remained largely unnoticed in the western side.

Around these time, oblivious of the works of Ekimov, Brus and his group including Bawendi (as post-doc fellow) while working at Bell Labs to use solar energy to initiate chemical reactions using cadmium sulphide (CdS) nanoparticles floating freely in a fluid observed that the optical properties of the CdS nanoparticles was size-dependent. They used CdS nanoparticles to absorb light which can be harnessed to drive chemical reactions.

In order to provide larger surface area on which the chemical reactions can take place they need to make the particle as small as possible, because smaller the particle larger is its surface area. Both Ekimov and Brus, therefore, had not exactly attempted to synthesize or develop quantum dots but they accidentally stumbled on quantum dots while working on nanomaterials but with different perspectives.

However, the methods they used to produce the quantum dots generally resulted in particles of varying sizes and often with defects. This had hindered the development of the quantum dots and their commercial exploitations. Everyone including the Chemist Bawendi who started his postdoctoral training at Brus' laboratory was working on development of new reliable methods for producing good quantum dots. It was just not forthcoming.

Not deterred by the failures at the Bell Labs, Bawendi after joining as research leader at MIT still continued his efforts to synthesize higher quality quantum dots. It was only in 1993 he came out with a major breakthrough in the synthesis of quantum dots known as the 'rapid injection method'. When his research group injected the substances that would form nanocrystals into a heated and carefully chosen solvent by injecting as much of the substances as was necessary to precisely saturate the solution for the tiny crystal embryos to begin to form simultaneously.

This new path breaking method made it possible to develop quantum dots of a specific size with smooth and even surface by dynamically varying the temperature of the solution. The quantum dots thus produced were almost perfect giving rise to distinct quantum effects. Because of the ease with which precise quantum dots can be produced, more scientists started investigating the unique properties of quantum dots - the Bawendi method is indeed truly revolutionary.

It fact it is Bawendi's high-quality 'rapid injection method' of production of perfect quantum dots that paved the way for their wider commercial and medical application. It has already revolutionized from LED (Light Emitting Diode) or OLED (Organic-LED) to QLED (Quantum dot LED) in display monitors or smart TV screens, etc.

Now one can have Core type Quantum dots (CQDs) of single component materials with uniform internal compositions, or Core Shell type Quantum dots (CSQDs) in which small regions of one material is embedded in another with a wider band gap, or Alloyed Quantum dots (AQDs) in which two semiconductors with different band gaps are alloyed which showed both composition and size tuneable properties. Since the properties of matter is now shown to size dependent, the properties of matter is not only a function of its valence electrons but also its size - requiring revisit of the principles of the Modern periodic Table!

Quantum dots is certainly not the last word in the quantum world, the next in the line perhaps is the Quantum Computers which is based on qubits (quantum bits) that can exist in multiple states simultaneously due to quantum superposition principle rather than bits (binary digits) in the so called classical computers where everything is in either 0 or 1 state.

For example, a coin can exist as Head or Tail state only but in quantum computer the coin can simultaneously exist in superposition of both Heads and Tails states. Quantum computers can compute exponentially faster with enormous variables with enhanced capability for solving much more complex phenomena.

While the chemistry Nobel 2023 is on the development of matter at much smaller length scale, the Physics Nobel Prize 2023 is on development of much smaller time scale, Agostini, Krausz and Huillier developed experimental methods that generate attosecond (10-18 s) pulses of light for the study of electron dynamics in matter.

Femtosecond (10-15 s) was once considered as the limit for the flashes of light it was possible to produce and now it is attosecond - the timescale at which the properties of an electron change! Will there ever be a limit to human imagination and the run for chasing the imagined situations!

The 2023 Nobel Prize for Physics and Chemistry perhaps is sending a subtle message to switch from the age old cliché 'Think Big' to 'Think Small and Remain small' and one should not grow older and become 'Wider and Weightier' like many of us do consciously or otherwise. Bulky groups, as they say in organic chemistry, are good leaving groups and why should one be in a hurry to leave the universe earlier than expected?

One should grow older and become 'Wirier, Wiser and Wealthier' leisurely looking forward to quantum effects to set in!


* Prof Homendra Naorem wrote this article for e-pao.net
The writer is serving as a Professor in the Chemistry Department, Manipur University
and can be contacted at naorem(DOT)homendra(AT)gmail(DOT)com
This article was webcasted on 12 October 2023.



* Comments posted by users in this discussion thread and other parts of this site are opinions of the individuals posting them (whose user ID is displayed alongside) and not the views of e-pao.net. We strongly recommend that users exercise responsibility, sensitivity and caution over language while writing your opinions which will be seen and read by other users. Please read a complete Guideline on using comments on this website.




LATEST IN E-PAO.NET
  • 12th Legislative Assembly #2 : Gallery
  • Violence in Manipur 2023-2025 : Timeline
  • Education & its disjuncture in Manipur
  • HUN-Thadou Cultural Fest 2025 : Theme
  • Coo :: Poem
  • Agartala Coach : India U-19 Women Cricket
  • The story of the village of hope
  • Career choice in wetlands
  • CM in Delhi to meet Shah
  • After failed plastic ban bid, on brickfields
  • New catfish species discovered in Chakpi
  • Love, Unsure :: Poem
  • Manipur's border battles: Deeper conflict
  • A world without leprosy
  • Origin of corruption & possible remedies
  • The question of life
  • 'Sereki' unveils Majuli-themed campaign
  • Posers over summons to Delhi
  • Addiction-free campaign
  • Mera Chaorel Houba @Kangla #5 : Gallery
  • Lamtanganba, Adum , Mahaiso : eMing
  • Manipur : Champions Jr Natl Sepaktakraw
  • Effective Unified Command approach
  • Saurashtrian Tamils
  • Accepting the change :: Poem
  • From Kumbh to heaven direct
  • Edge of the seat suspense
  • Wetlands revival efforts reaping fruit
  • Natambakta : Play by JNMDA #4 : Gallery
  • EIIFF 2025 unveils Festival Memento
  • Climate change & plant diseases
  • Shija Hospital- AHPI Healthcare Award
  • Budget 2025: A big gift for middle-class
  • The Science of Success : Attitude #2
  • Cakeology 2025: India's largest cake expo
  • Need to stick to a consistent narrative
  • Leniency on tobacco ban aiding demographic
  • 76th Republic Day @ Kangla #2 : Gallery
  • Pheiroijam Christina - 21st Miss North East
  • Manipur: Gold at 28th Jr National Sepaktakraw
  • Clarion call for redeeming our rightful future
  • The Power of Poppy - 67 :: Poem
  • Clean energy for sustainability
  • Union Budget: Industrialists from NE speaks
  • Balaram Sougaijamba: General of Manipur
  • Nikhil Okram crowned 14th Mister North East
  • Chadong village: Rising from waters with hope
  • Financial literacy for common man
  • Obituary: (L) Pu Thangkholen Sitlhou
  • Nail care in Winters
  • State of war since 2023: No winner, only losers
  • Talks on new district row
  • Radio E-pao: 1000+ songs from Manipur
  • Maibi Jagoi @ Kwak Tanba : Gallery
  • February Calendar for Year 2025 : Tools
  • Ballad of Letting Go :: Poem
  • 2nd Eikhoigi Imphal International Film Fest
  • Deeper exploration of term 'Hill-Valley Divide'
  • Children's Book to adopt 'Look East Policy'
  • Pony registration & conservation
  • Endless suffering of internally displaced child
  • 21st Ningtham Kumhei Fest #2 : Gallery
  • Thiyam Suryamukhi conferred Padma Shri
  • Isolate Kuki Militants by facilitating safe return
  • Sports Meet held at Rongdai Village
  • Eco-Apocalypse: Prevent collapse with Green
  • Grand Finale : 21st Mega Miss North East
  • Time to give more teeth to ST demand
  • 5 years of ILP; what about NRC demand ?
  • Remembering Md Ladu, celebrated polo player
  • The Lament of Love's Deceit :: Poem
  • Need for inculcating value based education
  • Royte - Times Young Entrepreneur Award
  • Glass Child Syndrome ! 'Sibling rivalry'
  • 6 Films for NE Section at GAFF 2025
  • Pony registration & conservation
  • Impartial anti-extortion cell need of the hour
  • 76th Republic Day @ Kangla #1 : Gallery
  • Conservation Strategies of Pethia manipurensis
  • Remembers 13 Brave Indian Soldiers
  • Workshop: Intl Year of Quantum Science
  • Governor's role and discretionary powers
  • Physics workshop for educators at Agartala
  • Who wins Delhi - Daru or Dharma
  • War on Drugs: A war Manipur cannot loses
  • NE turning into transnational drug hub
  • Essence of Gaan-Ngai #2
  • Manipur's dystopian reality
  • The day Light reached the hills
  • 2nd Eikhoigi Imphal Intl Film Fest 2025
  • Why is depreciation of rupee not stopping ?
  • An introduction to Rabies (Hydrophobia) #5
  • Thoithoiba Yelhou Yangkok Artist #2 : Gallery
  • Republic Day Titbits
  • NIT Manipur: Best Design Award @VLSI Design
  • The Power of Poppy - 66 :: Poem
  • Grand Finale: 14th Mega Mister North East
  • Application : FILMART, Hong Kong
  • The Science of Success : Attitude #1
  • 21st Ningtham Kumhei Fest #1 : Gallery
  • Demographic for balkanisation of Manipur
  • Training on Mushroom Cultivation at Nambol
  • Jugeshwor Kshetrimayum receives GELA 2025
  • Construction Committee of Meetei Yumpham
  • Call against misuse of social media
  • Positive & negative aspects of social media
  • In Search of Peace in Manipur
  • Embracing the Shadows :: Poem
  • Dr Manmohan Singh will live on
  • Rise in the price of medicines
  • Respecting the dead- Denying is a disgrace
  • Winter skin care tips for oily skin
  • Illegal immigrants :: Of FMR & border fencing
  • JD-U row exposes national parties' apathy
  • State Gaan-Ngai @Sagolband #2 : Gallery
  • On 'Only BJP can save Manipur'
  • Frontline health workers dispelling darkness
  • 14th East Himalayan Trade Fair
  • Life is plastic
  • Killers on the road : 834 lives lost
  • Call to action to save State's wetlands
  • Essence of Gaan-Ngai #1
  • The Taste of Dreams wins @Red Intl Film Fest
  • Science: 3rd eye for Meitei-Kuki reconciliation
  • Northeast flies high in direct selling
  • Mastering focus amidst distractions
  • An introduction to Rabies (Hydrophobia) #4
  • Indo-Naga Talks (From 2012) :: Timeline
  • BJP : Tepid response from the hills
  • BABINA Hospital sets example in healthcare
  • Nitya Ras @Nongmeibung #1 : Gallery
  • Agonizing reality of our country's veteran elites
  • Historicising the colonial narratives
  • NSS Team Departs for National Integration
  • HUN-Thadou Cultural Festival 2025
  • Time to recreate Naga Peoples Convention 2.0
  • Career in nutrition
  • Need to give more meaning to War on Drugs
  • Time for real action not empty rhetoric
  • Foundation: Manipur Press Club #2 : Gallery
  • "Aronba Wari" :: Shumang Leela Synopsis
  • Tripura's livelihoods challenges
  • Archaeological Exhibition @ Kangla : Gallery
  • Gaan-Ngai @Chaopok village #1 : Gallery
  • Manipur needs to affirm her tribal roots
  • Madras/Chennai- 1989 till 2024 : Gallery
  • Investigate "arms recoveries" in Mizoram
  • Training on Mushroom Cultivation
  • NE Direct Selling Conference & Expo
  • Response of Delhi in last 20 months
  • Regulated entry after FMR scrap, border
  • Mutua Bahadur : Preserving Manipuri culture
  • Competitive Altruism: Resolving ethnic conflict
  • Pithe Puli Utsav at Agartala
  • Building the best version of yourself
  • Guwahati Asian Film Festival 2025
  • Tips to keep your lips soft & smooth in winter
  • Subsidised flight tickets for all
  • MCPCR alert on child trafficking fear
  • Imoinu Erat Thouni @ Wangkhei : Gallery
  • Gaan-Ngai celebrating Culture in Delhi NCR
  • The Weeping Gods of Manipur :: Poem
  • Disarming Kuki-Zo armed groups under SoO
  • Why nurses deserve more recognition, pay
  • The hidden truths of our social media lives
  • MMTU stand bang on target: Recapping May 3
  • Enhancing aerial options to ease travel woes
  • 2nd Emoinu Fish Festival #1 : Gallery
  • Sustainable development - climate action #1
  • RIST Talk- 62 : Artificial Intelligence (AI)
  • "Technically a BJP MLA will rule Nagaland"
  • Makar Sankranti : vibrant customs & traditions
  • Why gold is a strong hedge but ...
  • Delhi date on January 17
  • Onus of addressing tribal issues on new Guv?
  • Nupilal Ningshing Lamjel #2 : Gallery
  • Licypriya Kangujam: Nat'l Youth Day Award
  • Barak Festival advocates Peace, Progress
  • 'Yu', not fully liberalised
  • Article 355 equals Governor's Rule ?
  • Calls to vote with conscience
  • Zingtun academy leading by example
  • State Gaan-Ngai @Sagolband #1 : Gallery
  • Is Kuki-Zo community pushing Nagas to edge?
  • Will drive to find-treat-prevent TB continue ?
  • Smart Cities, dustier roads ?
  • ST of NE & Dalits of mainland India
  • That May :: Poem
  • Understanding Red, Yellow, Green
  • Cong posers on Govt aid to SoO group
  • Culturals @Tri-Nation Football #1 : Gallery
  • Gaan-Ngai festival of Kabui/Rongmei
  • 40 Years & 04 Stations- Part IV (Madras)
  • Manipur Gold: 34th Sr Natl Sepaktakraw C'ship
  • Public Health Risk Management Training
  • The Power of Poppy - 64 :: Poem
  • The Science of Success #4
  • Hingminashi Eikhoi : Call for unity in diversity
  • A Hymn for Goddess Emoinu
  • Are the foods we eat, correct ?
  • Gangtok, Sikkim (1983 till 1988) : Gallery
  • The Taste of Dreams : Teaser Unveiled
  • Be a child of courage & conquer obstacle
  • Hans Renal Care Centre in Guwahati
  • Focus on pre-May 3, 2023 period
  • Conundrum over the genesis of crisis
  • Misna Chanu aids to Jiribam IDPs : Gallery
  • North-East Students invited to JEE Main 2025
  • Empower the State else avoid blame on CM
  • Obituary : Thaunawjam Brajamohon
  • Hope :: Poem
  • An introduction to Rabies (Hydrophobia) #3
  • Winter makeup tips for dry skin
  • Imphal, Delhi still groping in the dark
  • Tension over assault case, land claims
  • Mega Protest Rally, end AFSPA #2: Gallery
  • Foundation: Manipur Press Club #1 : Gallery
  • Ningol Chakkouba @ Delhi #3 : Gallery
  • Indigenous Pottery Making @Imphal : Gallery
  • AIR Radio Imphal Station - Live streaming
  • Nupi Lal Memorial @Pune #2 : Gallery
  • The historical account of Kabaw Valley #3
  • Featured Front Page Photo 2024 #6: Gallery
  • E-Pao.net : 25th Anniv & 2025 Wishes
  • Protest @Delhi - Murder of Meiteis #2: Gallery
  • "Connections", art exhibitt @ DC : Gallery
  • Observance of Thang-Ta Day #1 : Gallery
  • Mera Chaorel Houba #4 : Gallery
  • Nupi Lal Memorial @Pune #1 : Gallery
  • Meitei Mayek Tamba : Online Classroom #5
  • Indigenous People Cultural Fest #1 : Gallery
  • Maibi Jagoi @ Mera Houchongba: Gallery
  • Mega Protest Rally, end AFSPA #1: Gallery
  • Ta Ta TabuHtoN :: Seireng
  • Downloadable Manipuri Calendar :: 2025
  • GHOST of PEACE :: Download Booklet