What is the structure of Qdot?

Structure of Quantum Dot (Qdot)

Quantum dots (Qdots) are nanometer-sized semiconductor particles that have unique optical and electronic properties due to their size and shape. The structure of a quantum dot determines its optical properties, which can be tuned by changing the dot's size, shape, and material composition.

Core: The core of a Qdot is made up of semiconductor material, typically consisting of elements from groups II-VI (like CdSe, CdTe) or III-V (like InP, InAs) of the periodic table. The core is responsible for the quantum confinement of charge carriers (electrons and holes).

Shell: Surrounding the core is a shell made from another semiconductor material with a wider bandgap. The shell helps to passivate the surface of the core, protecting it from the environment and reducing nonradiative recombination. A typical shell material for a CdSe core Qdot would be ZnS.

Ligands: The surface of the Qdot is coated with organic or inorganic molecules known as ligands. These ligands stabilize the Qdot particles, prevent them from aggregating, and provide solubility in various solvents. Ligands can also be functionalized to target specific molecules or cells for biological applications.

Optical Properties: Qdots have size-tunable fluorescence emission, meaning the color of light they emit can be precisely controlled by changing the size of the core. Smaller dots emit light at shorter wavelengths (blue region), while larger dots emit light at longer wavelengths (red region).

• Biological imaging
• Quantum computing
• Solar cells
• Light-emitting diodes (LEDs)

The advanced structure of Qdots provides a platform for a myriad of applications across different fields such as medical diagnostics, renewable energy, and electronics and has opened up new frontiers in nanotechnology.