Quantum dots are tiny crystals of semiconductor material, roughly 2-10 nanometers, containing only hundreds to thousands of atoms. They have the potential to capture energy from sunlight photons much more efficiently than conventional crystalline silicon solar cells. They convert sunlight to electricity more efficiently through what is referred to as "multiple exciton generation." While the photovoltaic effect in conventional solar cells only excites one electron to create one free electron-electron hole pair per photon, in quantum dot cells each photon can produce multiple free electron-electron hole pairs.
Quantum dot cells could prove to be less costly to manufacture when fully commercialized, but currently, they are still in the research and development stage of technology maturity. Nevertheless, the development of these quantum dot solar cells has so far been extremely fast compared to the development of many previous solar cells, such as crystalline silicon solar cells that took decades to become a commercially used material in the solar industry.