Quantum dots are tiny semiconductor particles, typically on the nanometer scale, that exhibit unique optical and electronic properties due to their size and composition. These nanocrystals are used in various applications, including displays, solar cells, and medical imaging. Quantum dots emit light of specific colors when excited by external energy sources, making them valuable in producing vibrant and energy-efficient displays in devices like televisions and smartphones. Additionally, their potential in medical imaging allows for precise tracking of biological processes within the body. Quantum dots are an exciting area of research and innovation with promising prospects in multiple fields.
When we manipulate things on this scale, we say that we are working at the Nanoscale. What kind of things are we going to do at the nanoscale that are so significant. When we want to excite an atom, we give it energy. The electron becomes excited and jumps to the high-energy orbit. The electron can remain in that orbit for some time. But it is unstable there, and after some time, it jumps back to its previous orbit to radiate light (Photons) where we find a ray of light. Now, this phenomenon will be taken on a bigger canvas.
A quantum dot is an artificial sphere. We make this artificial sphere with the help of an atom. What is significant about this sphere? When we pack a lot of atoms in one place to give them energy, several electrons will jump into a higher energy level. The atoms that have been packed in a place have some qualities. They will not use any specific light for their excitation. If we give the single atom red light, it may become excited. However, if we give it blue or other light, it may not become excited. But in the quantum dots, we can give light in a bigger band like red, blue, yellow, etc to excite electrons. It means that light responds to a bigger part of the quantum dot. Therefore, the excitation spectrum is significantly large in the quantum dots. When all the electrons jump back to the low energy level, they radiate the light of a very narrow band, but it is a very clean light. These atoms are semiconductor atoms.
When we stimulate ordinary atoms such as those found in Silicon or Germanium, we observe varying types of light due to differences in their energy gap. However, in quantum dots, the light we expose them to does not depend on the structure of the material or the atoms used. Instead, the type of light produced depends solely on the size of the quantum dot. When observing the energy bands of quantum dots, we can see that the band furthest from us emits blue light. As the size of the material increases, it emits red light. When it is slightly smaller, it emits green light, and when it is further reduced in size, it emits blue light. However, the output of this process is very precise and depends solely on the size, rather than the structure. As a result, it remains the same despite any changes in the structure.
The output radiations are extremely narrow-band. The guard that stands at the output doesn't let every color emit. It allows only a specific kind of color to emit and stops the rest. This is a significant point due to which the colors or radiations we receive from quantum dots are extremely vibrant and beautiful and they don't overlap.
It is structure consists of a single core having all the optical properties. It does all excitation and de-excitation activities. It is a dot type of structure. Therefore, it is called a quantum dot.
The first advantage of the quantum dots is when we study a cell to track a molecule, how we will do it. We can do it with the help of quantum dots. We will label it with a quantum dot with a specific color. Now, we can track it wherever it goes and can note its engagement and reactions with other molecules and what it is producing. So, we can track the chemical reactions and other functions that occur inside the cell with this amazing invention.
Quantum dots remain molecularly active which is its second significant property. It means we can attach a protein or other molecules to it. Therefore, when we attach other molecules to it, they can react in the same way inside the cell as other molecules do. So, we can initiate chemical processes in the cell with the help of quantum dots.
Quantum dots can also play a vital role in the neurosciences as there are specialized cells. The structure of neurons is different. Therefore, studying things in these cells is difficult. Here, we also tag molecules with quantum dots and track them where the molecules make the synaptic connections. We use quantum dot technology to track the chemical exchange taking place at these synaptic connections. Quantum dot technology is used for tracking at the cell level and plays a significant role in brain imaging.
A QLED 8K TV with 33 million pixels for optimal viewing in bright rooms or near the windows. This much more advanced TV as compared to a 4K TV as it gives 4 times better resolution than a 4K TV while 16 times better than an HD TV. Quantum dot technology will be used in these LEDs.
Quantum dot technology is also advancing at a tremendous speed in the space. It will be used in quantum spectrometers in space. We will study light that comes from different planets, stars, and black holes. It will revolutionize space technology at an enormous speed and level.
According to Richard Feynman in 1960, if you want to understand how nature works, you have to make matter on the same length scale. It is not only an engineering and technological challenge but also a computing challenge. We will produce such chips that will work on the quantum level in the near future. A University of New South Wales and Silicon Computing team produced the first quantum computing chip. We know that an integrated circuit is a small component made from semiconductor-based electronic devices like transistors, diodes, resistors, or capacitors with the help of which we design various computers and microchips to do enormous computations. A world record holder Supercomputer that is called Summit Supercomputer performed a calculation in the recent past at Oak Ridge Lab that broke all the previous calculations. This computer used 27,600 GPUs to calculate the interaction of a simple protein in 11 minutes. It simulated a simple protein and its inside interactions that contained 45,000 atoms and 180,000 electrons. The biggest supercomputer in the world is known as Frontier which has 9,408 CPUs, 37,632 GPUs, and 8,730112 cores, and the cable that links it is 145 kilometers long. Despite its massive size, it can't simulate simple and normal proteins. But quantum dot technology-based Silicon chips will simulate more complex and huge molecules that will bring revolution in the realms of technology, medicine, and material sciences.
FAQs
What exactly is a quantum dot?
A quantum sot is a tiny semiconductor particle with unique properties, emitting specific colors of light when stimulated. They're used in displays for vibrant colors and have applications in areas like medical imaging and solar energy.
What are quantum dots used for?
Quantum dots have a range of applications, including:
Displays: Quantum dots enhance color accuracy and energy efficiency in displays, like TVs and computer monitors.
Medical Imaging: They enable precise imaging in medical diagnostics, aiding in the detection and treatment of diseases.
Solar Cells: Quantum dots can improve the efficiency of solar panels by capturing a broader spectrum of light.
LED Lighting: They enhance the quality of LED lighting, producing brighter and more vibrant colors.
Biological Labeling: Quantum dots are used to tag and track biological molecules and processes in research and diagnostics.
Environmental Sensing: Quantum dots can be used in environmental sensors to detect pollutants and other substances.
These applications show the versatility and potential of quantum dots in various industries and technologies.
What is quantum about quantum dots?
The "quantum" in quantum dots refers to the quantum mechanical properties that these nanoscale semiconductor particles exhibit. At such tiny sizes, the behavior of electrons within quantum dots is subject to quantum physics principles, particularly quantum confinement. This means that the behavior of electrons is restricted and quantized, leading to unique optical and electronic properties. Quantum dots emit light of precise colors when excited by an energy source, and their electronic characteristics can be fine-tuned by controlling their size, composition, and structure. This quantum behavior makes quantum dots valuable in various applications, such as displays and medical imaging, where precise control over light emission and electronic properties is crucial.