The authors have declared that no competing interests exist.
Quantum dots can be defined as semiconductor nanostructures which are artificial in nature and ranges from 2-10 nm in size. These tiny nanocrystals become excited under illumination and emits colors of different wavelength. Quantum dots possess unique properties determined by their structure (hollow or solid), size, shape and composition. Fabrication of Quantum dots is achieved by several methods such as electron beam lithography, epitaxy or by means of colloidal synthesis.
The word ‘Quantum’ itself is derived from a Latin word meaning ‘amount’ and can be defined as small unit of physical property like energy or matter
Physiochemical Properties of Quantum dots is mentioned in
S.no | Physiochemical Properties | |
1 | Size | Microscopic, 2-10nm (10-50 atoms) |
2 | Configuration | Confined in three-dimensions |
3 | Highly tunable | Variable core sizes make them give off different colors by tuning/changing the characteristic wavelength of emitted light |
4 | Excitable | Can excite to higher energy level to emit light of respective wavelength |
5 | Shapes | Various including cubes, spheres and pyramids |
6 | Resistance | Resistance to photo-bleaching, photo-degradation and chemical- degradation |
There are 3 types of Quantum dots on the basis of their composition and structure
Quantum dots that have internally uniform structures which is composed of a single material
Also known as Core-Shell semi-conducting nanoparticles having variable photophysical properties e.g ZnS
Multicomponent semiconductor nanoparticles e.g. CdS-Se/ZnS
There are 3 main approaches through which quantum dots can be prepared
1. Electron beam lithography
2. Colloidal synthesis
3. Epitaxy such as Vapor Phase epitaxy, liquid phase epitaxy,molecular beam epitaxy etc
Used in Solar cells and photo-voltaic e.g. Graphene quantum dots
Used as fluorophores which helps in bio-sensing and bio-tagging
Used as a catalyst to form hydrocarbons
Luminescent quantum dots (LQD) are used in high quality displays and lighting systems
Quantum computing uses quantum computer that store information in quantum bits
Magnetic quantum particles are used in memory chips
Used in communication devices like lasers
Have biological applications including in vivo and invitro imaging, DNA assays and microarrays,labelling tumors , diagnosis /treatment of cancer , drug delivery
Quantum dots have many exceeding rewards, but they do have drawbacks like they are costly, toxic, may cause environmental pollution etc
Due to their excellent intrinsic and extrinsic properties, Quantum dots continues to amaze researchers with their immense applications.