Controllable synthesis of dual emissive Ag:InP/ZnS quantum dots with high fluorescence quantum yield

Abstract

Dual emissive Cd-free quantum dots (QDs) are in great demand for various applications. However, their synthesis has been faced with challenges. Here, we demonstrate the dual emissive Ag:InP/ZnS core/shell QDs with the excellent photoluminescence quantum yield (PL QY) up to 75% and their PL dependence on the reaction temperature, reaction time, the different ZnX2 (X=I, Cl, and Br) precursors, the ratio of In/Zn and the Ag dopant concentration. The as-prepared Ag:InP/ZnS QDs exhibit dual emission with one peak position of about 492nm owing to the intrinsic emission, and the other peak position of about 575nm resulting from Ag-doped emission. These dual emissive QDs are integrated with the commercial GaN-based blue LEDs, and the simulation results show that the Ag:InP/ZnS QDs-based white LEDs could realize bright natural white-lights with the luminous efficacy (LE) of 94.2-98.4lm/W, the color rendering index (CRI) of 82–83 and the color quality scale (CQS) of 82–83 at different correlated color temperatures (CCT). This unique combination of the above properties makes this new class of dual emissive QDs attractive for white LED applications.