Quantum Dots in Solution (green)

This vial contains quantum dots, which show strong green fluorescence when exposed to UV light. Since the early 1990s, quantum dots have been the subject of intense academic and industrial research because of their possible impact in many areas of science and technology. The quantum world is the domain of atoms and molecules, and very strange and unintuitive things happen down there. Sub-atomic particles play by their own rules; they can exist in two places at once, they can be simultaneously waves and particles, and they can flip in and out of existence. This world is often beyond our understanding, let alone control. However, quantum dots represent a state of matter where the often unintuitive consequences of quantum mechanics become tangible. 

Quantum dots are nano-sized inorganic semiconductor particles. These semiconductors are pervasive in technology, and there use in transistors formed the basis of the electronics revolution in the 20th century. When reduced down to the nanoscale, they exhibit interesting properties, the most useful being their extremely bright fluorescence. Quantum dots are actually grown from the bottom up in solvent solutions, meaning they crystallise and grow in a liquid, rather than being chopped down from big lumps of semiconductor. Although quantum dots are solid particles, they remained dispersed in the solution as they have a special surface capping layer which allows them to stay dispersed without sticking together and forming big lumps.