Preparation Of ZnO/MgO Core-Shell Quantum Dots And Their Luminescent Properties

Zinc oxide(ZnO)is a typical wide band gap semiconductor material,and its quantum dots not only have unique characteristics which is different from their body material,but also have excellent quantum properties such as quantum size effect,quantum confinement effect.ZnO quantum dots have been widely used in UV detector and Ultraviolet light-emitting diode.Firstly,the preparation and characterization of ZnO core-shell quantum dots were studied.In view of the many defects of ZnO quantum dots,MgO was used to encapsulate ZnO,which improved the storage life of ZnO quantum dots and reduced the defects,and enhanced the near-edge ultraviolet luminescence.A variety of quantum dots materials were prepared by adjusting the preparation parameters,such as reaction temperature,growth time,raw material ratio.The characterization of ZnO/MgO core-shell quantum dots was studied by means of microscopic structure and optical properties.Secondly,the application and the electroluminescence of ZnO/MgO core-shell quantum dots were studied in this paper.The stable performance of light-emitting diodes was made of the quantum dots and the organic materials(PVK,PEDOT:PSS)by whole solution method,achieving the ZnO/MgO core-shell quantum dots' electroluminescence.There is a good energy level matching between the quantum dot layer and the PVK,which is to be the hole transport materials,and the PEDOT:PSS has enhanced the hole transport capacity.The device's performance has been optimized by adjusting the spin-coating speed,film annealing and other process parameters.From the device's electroluminescence spectrum,it can be seen that there are four emission peaks,and the device exhibits a composite white light as a whole.The near-band ultraviolet emission peak(about 370 nm)of ZnO/MgO core-shell quantum dots has been enhanced and the defect emission peak is also suppressed,which lay the foundation for the further study of ZnO/MgO core-shell quantum dots.