Quantum Dots
Quantum Dots
Quantum dots (QDs) are semiconductor particles that are only a few nanometers in size, and they exhibit unique optical and electronic properties due to quantum mechanics. These properties make quantum dots particularly interesting in a variety of technological applications, including quantum dot displays, solar cells, and lasers.
Properties and Composition
Quantum dots are typically composed of semiconductor materials such as cadmium selenide or indium arsenide, although carbon quantum dots and graphene quantum dots also exist. The size of the quantum dots affects the wavelength of light they emit, a property that is exploited in quantum dot displays to produce pure monochromatic colors.
Discovery and Development
The concept of quantum dots was first discovered by Alexey Ekimov in 1981, and has since been developed into a wide array of applications. Notably, Moungi Bawendi made significant advances in the chemical production of high-quality quantum dots, earning recognition in the scientific community.
Applications
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Quantum Dot Displays: Quantum dots are used in display technologies to improve brightness, color saturation, and energy efficiency. Nanosys is one of the companies that have commercialized quantum dot technology in consumer electronics.
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Solar Cells: In quantum dot solar cells, quantum dots serve as the photovoltaic material and offer potential advantages over traditional bulk semiconductor materials, such as tunable band gaps and enhanced light absorption.
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Lasers: Quantum dot lasers utilize quantum dots as the active medium for light emission, benefiting from reduced threshold currents and improved temperature stability.
Relation to Other Technologies
Quantum dots can be synthesized to enhance the thermoelectric effect, which is the direct conversion of temperature differences to electric voltage. This effect is utilized in thermoelectric generators that convert heat to electricity, often applied in technologies like multi-mission radioisotope thermoelectric generators used by NASA.
Moreover, quantum dots have potential applications in atomic batteries. These batteries, also known as nuclear batteries, employ radioactive materials to generate electricity through the decay process, a technology distinct from conventional electrochemical batteries. Materials such as promethium-147 are used in these systems to provide long-lasting energy.