Unveiling the novel interfacial anchoring effect of neodymium(III) for realization of blue-emitting InP/ZnS quantum dots

Abstract

Colloidal indium phosphide (InP) quantum dots (QDs) have attracted worldwide attention due to their intrinsic environmental friendliness and excellent optical properties. The incorporation of metal ions has been a common way to modify the properties of InP QDs and some metal ions have been confirmed to be effective in preparation of blue-emitting InP QDs. Herein, the interfacial anchoring effect of rare earth metal ions neodymium(III) (Nd3+) is unveiled for the first time by analyzing the alteration of spectra, size, and composition of QDs after Nd doping. It is evidenced that Nd substitutes for In of InP during the process of nucleation. More crucially, Nd is anchored at the surface of InP and inhibits their further growth at the high temperature of shelling. This ensures that the size of InP QDs and the absorption peak position are almost maintained during shell growth. It is demonstrated that the emitting wavelength of InP/ZnS core/shell QDs is systematically tunable through varying Nd amounts. Finally, the optimized InP/ZnS QDs exhibiting an emission peak of 470 nm with a photoluminescence quantum yield of 44%, and a full width at half-maximum of 46 nm are prepared.