What does QD mean in PHYSICS

A quantum dot is a tiny semiconductor particle that can be used in electronics and optics. It consists of semiconductor material like cadmium selenide (CdSe) or cadmium sulfide (CdS) encapsulated in a core shell such as zinc sulfide (ZnS). The size of the particle determines its ability to absorb and emit light of different wavelengths.

Quantum dots interact with light by absorbing it at their surface, which causes electrons within the dot to become excited and emit a photon at an energy level corresponding to the wavelength of the absorbed light. This process is known as photoluminescence, and it enables quantum dots to produce specific colors when excited with different wavelengths of light.

Quantum dots are used for many applications including displaying images on televisions and computer monitors, electron microscopy imaging, optical sensors, drug delivery systems, solar cells, LEDs and bioimaging.

Quantum dots offer several advantages over traditional components such as enhanced brightness and efficiency; high luminescence intensity; tunable emission spectrum; low biodegradeability; excellent optical properties; cost effectiveness; improved performance over wide temperature ranges; wide range sensitivity; good stability under high temperatures; nanosize dimensions; room-temperature fabrication processes ;and higher power efficiency.

Quantum dot devices generally last longer than traditional components because they have no moving parts that can wear out due to usage or vibration. Additionally, their small size means they require less power than larger components so they generate less heat, reducing the risk of damage due to overheating or thermal shock.