Highly efficient and stable InP/ZnSe/ZnS quantum dot-light-emitting diodes
Quantum dot-light emitting diodes have been in spotlight as an ideal display because of their excellences in the efficiency, color purity and soluble fabrication. Although intensive efforts have been put to enhance their efficiencies, it is necessary to improve the operating stability and to replace the Cd composition with environmentally benign materials. However, the performances of the InP-based materials and devices are still far behind those of the Cd-containing counterparts. Here, we disclose a novel synthetic method to control the growth kinetics and interfaces of the InP/ZnSe/ZnS quantum dots resulting perfect quantum yield, narrowest emission, and highest uniformity ever reported. Also, the mid-shell thickness was engineered for better radiative recombination, and the surface ligand was tailored for better charge injection. Finally, we achieved excellent device performances such as theoretical efficiency and high brightness and extremely long lifetime, which marked same level of the state-of-the-art quantum dot displays.