Quantum Dots

Quantum dots (QDs) are novel semiconductor nanocrystals that emit light in varying wavelegths across the visible spectrum depending on their size, shape, and composition. These" tunable" optical properties are advantageous for solid state lighting, electronic devices, solar cells, laser diodes, medical imaging devices, and numerous other optoelectronic applications. Employing quantum dots as sources of light improves the performance and energy efficiency of high-resolution displays in devices such as smartphones and high-definition television screens.

Quantum dots can be manufactured in various forms. Core-type quantum dots are composed of a single material, typically a metallic chalcogenide such as cadmium telluride or lead sulfide. Core-shell quantum dots (CSQDs, or core-shell semiconducting nanocrystals, CSSNCs) consist of a core-type material encapsulated within a second semiconductor material with a higher band gap. These hybrid particles such as cadmium selenide-zinc sulfide exhibit an improved quantum yield over single material quantum dots. Alloyed quantum dots are also composed of multiple materials, but in a homogeneous mixture rather than distinct regions. The combination of two different semiconductors with different band gaps imparts new properties distinct properties to the particles that are distinct from the original materials.