Today, this blog will talk about “The Making of Quantum Dots.” A quantum dots are dot is a semiconductor nanostructure device. It encloses the motion of conduction band electrons, valence bonds electrons, or excitons in all three spatial orientations. The confinement can be caused due to electrostatic potentials. The presence of an interface between various semiconductor materials, or in the fact of semiconductor surface or because of a combination of both.
A quantum dot has an individual quantized energy spectrum. A quantum dot contains a finite number of elementary electric charges, i.e., conduction band, valence band holes, or excitons.
Size of Quantum Dots
Small-sized quantum dots like colloidal semiconductor nanocrystals can be as little as 20-10 nanometres, 10-15 atoms in diameter, and 100-100,000 atoms align under the quantum dot volume. Quantum dot that has self-assembled themselves are typically between 10-50mm in size.
At 10nm in diameter, approximately 3 million quantum dots can be lined up from end to end. And would fit within the width of an average human thumb.
History of Quantum Dot
A Russian physicist Alexei Ekimov at the end of the 1970s, incorporated nanocrystals of copper chloride and cadmium selenide in a molten glass matrix. In which he observed fluorescence and a gradient of colors. He published his first observations in 1980. Another Russian physicist Alexander Efros published his first theory to explain the behavior of the so-called small particles by the confinement of their electrons. Inspired by Alexie Ekimov, and American chemist Louis Brus, Bell Labs successfully tried and produced nanocrystals in liquid form. In this way, he first obtained Colloidal Quantum dots of cadmium sulfide, which is easier to handle, and published his results in 1983.
Due to their excellent optical properties, they’re used in the manufacture of very high-quality screens. With reduced energy consumption, they allow for better color rendering. They’re already utilized by some high-end manufacturers such as Samsung. The minimal size of Quantum dots makes it a bit tedious for production lines to handle them since their structure manages about 1000 times more significant phosphorus.
Materials used in Quantum Dot
- These quantum dots are made from a huge number of materials.
- The most generally utilized materials in the manufacturing of quantum dots are zinc sulfide, lead sulfide, calcium selenide, and indium phosphide.
- More applications will be utilized within the human body. So in order to avoid toxic elements from entering our body, they’ll be coated with a protective polymer.
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How are Quantum Dots Made?
- They can be manufactured in different ways that are from colloidal synthesis to chemical vapor deposition (CVD).
- The most ordinarily used and least expensive method is Benchtop Colloidal Synthesis.
- To make a number of ordered arrays of quantum dots on a substrate material, electrochemical techniques and CVD are utilized more frequently.
How do Quantum Dots Emit Light?
Quantum dots can be perfectly utilized to perform a wide range of valuable things. If an atom is given the energy, it gets exciting; you can likewise uplift an electron inside it to a higher energy level. Upon returning electrons to a lower level, the atoms emit a photon of light with the similar energy that the atom had initially been absorbed.
The color wavelength and frequency of light the atom emits depend upon what the atom is. For example, iron’s color is green, sodium is yellow, etc., and that’s by how their energy levels are set. One single rule is that different atoms emit different colors of light. Since the energy levels in atoms have set values (they’re quantized), quantum dots can emit light.
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How do you make a Quantum Dots?
- Since Quantum dots are exact crystals, they can be made similarly way other precise semiconductor crystals are made.
- One strategy is Molecular Beam Epitaxy (MBE). In this beams of atoms are fired at a substrate in such a way that a single-crystal gradually develops.
- The alternate way is X-Ray Lithography which is a kind of atomic-scale process of engraving utilizing X-Rays.
- Recent studies have likewise used biological processes such as feeding metals to enzymes.
Quantum Dots Applications
The following are the main applications of Quantum Dots:
- Optical applications: – It is used in all the places where precise control of colored light is of utmost importance. For example, a thin filter made up of quantum dots has been developed so that it can be fitted at the top of a fluorescent or LED lamp to help convert its light from blueish color to a much warmer, redder, or more attractive color. It has more attractive shades similar to that of an old incandescent lamp. They can also be used instead of pigments and dyes.
- Quantum Computing: – One method of utilizing quantum dots in computers is that it can be used to store and transmit data with the help of lights rather than electrons. A term is generally called “Photonics”. Optical computers can make use of quantum dots the same way traditional computers use transistors as the basic part of memory chips and logic gates. In quantum computers, binary digits won’t be stored by transistors but by ions, atoms, photons, or electrons entangled and will be acting as quantum bits known as “Qubits”.
- Chemical and Biological Use: – Quantum dots have discovered numerous applications in the field of medicines, but most importantly, they have found potential in the field of cancer. They can be designed to accumulate on the ideal body part, and afterward, they can start delivering nit-cancer drugs to them. Their most outstanding achievement will be targeting a single organ. It is much more precisely than the traditional use of drugs which has harmful side effects on the body. Plants love sunlight, and various plants prefer different wavelengths of light. Researchers are experimenting with quantum dots to concentrate on various color lights at plants to maximize their growth.
So this is all about the Making of Quantum Dot. Technology is growing very fast, and you should know everything about it. Info At One gives more importance to technology as it needs of the time.