Microwave-Assisted Synthesis of CdS/ZnS:Cu Quantum Dots for White Light-Emitting Diodes with High Color Rendition

High quality CdS/ZnS:Cu quantum dots (QDs) were first synthesized via a green microwave irradiation route. As-prepared core/shell doped QDs presented a strong absorption in the blue light region and highly efficient red to deep red emission with a maximum quantum yield of 40%. The composite formed by dispersing CdS/ZnS:Cu QDs into silicone resin showed an excellent photostability under blue illumination. Finally, high color rendition white light was generated from the CdS/ZnS:Cu QDs-assisted phosphor-converted white light-emitting diode (WLED) in which there was no reabsorption between quantum dots and phosphors. Under operation of 40 mA forward bias current, the fabricated WLED emitted bright natural white light with a high color rendering index of 90, a luminous efficiency of 46.5 lm/W, and the correlated color temperature of 6591 K. Simultaneously, the good color stability was accompanied by the CIE color coordinates of (0.3155, 0.3041) under different forward bias currents.