Enhanced tunable dual emission of Cu:InP/ZnS quantum dots enabled by introducing Ag ions

Transition metal ions doping has been an effective method to optimize the optical properties of quantum dots (QDs) and attracted much interest in recent years. In this work, Cu doped InP/ZnS (Cu:InP/ZnS) QDs have been synthesized via a nucleation-doping method and exhibit dual emission which consists of the intrinsic emission and the dopant emission. With the incremental Cu concentration from 0% to 10%, the dopant emission could be largely tuned from 598 to 707 nm. After introducing Ag ions into Cu:InP/ZnS QDs, the photoluminance (PL) intensity of dual emission gets remarkably enhanced with a PL quantum yield (QY) of 79%, while the emission peak positions change marginally. Through X-ray photoelectron spectroscopy, steady-state and time-resolved PL spectroscopy measurement, it can be concluded that the dopant emission color is mainly dominated by Cu while Ag is conducive to improve the dual emission of Cu and Ag co-doped InP/ZnS QDs. These results would contribute to further understanding dopant-dependent interaction and render this new class of single-phased and dual-emissive QDs a promising future to be applied in white LED.