One-pot synthesis of color-tunable copper doped zinc sulfide quantum dots for solid-state lighting devices

Color-tunable semiconductor quantum dots (QDs) are highly attractive for a wide range of applications including imaging, sensing, and lighting. Herein, we reported a facile synthesis of copper-doped zinc sulfide quantum dots (ZnS:Cu QDs) with tunable emission colors, using a microwave-assisted one-pot reaction. 3-mercaptopropionic acid (MPA) was used as a stabilizer agent and sulfide source for the formation of ZnS:Cu QDs. The photoluminescence of ZnS:Cu QDs showed a clear red-shift as increasing Cu concentration, which can be controlled by microwave irradiation time. As increasing the irradiation time, the emission color (peak) of ZnS:Cu QDs changed from blue (500 nm) to green (540 nm), yellow (580 nm), and to orange-red (595 nm). The obtained ZnS:Cu QDs were highly luminescent, as evidenced by their high quantum yields. The potential utility of ZnS:Cu QDs as a novel lighting source was demonstrated in a near-UV chip-based white light-emitting diode.