Optical Properties of Ultraviolet Quantum Dot Light-Emitting Devices Using ZnO-Cores With a MgO-Shell

Colloidal quantum dots (QDs) with a ZnO core were synthesized with subsequent surface passivation by MgO. The photo-enhancement effect of the near band-edge photoluminescence (PL) in ZnO nanocrystals, dispersed in ethanol, is investigated by observing changes in the optical properties after ultraviolet (UV) exposure. Finally, the operation as a light-emitting device (LED) was demonstrated experimentally for these ZnO-based quantum dots (QDs). The results indicate that this type of QDs might enable the development of electroluminescent UV sources in the near future.