Simple Synthesis of CuInS(2)/ZnS Core/Shell Quantum Dots for White Light-Emitting Diodes

In this study, the CuInS(2)/ZnS core/shell quantum dots (QDs) were prepared via simple and environmentally friendly solvothermal synthesis and were used as phosphors for white light-emitting diodes (WLEDs). The surface defect of the CuInS(2) core QDs were passivated by the ZnS shell by forming CuInS(2)/ZnS core/shell QDs. By adjusting the Cu/In ratio and the nucleation temperature, the photoluminescence (PL) peak of the CuInS(2) QDs was tunable in a range of 651–775 nm. After coating the ZnS layer and modifying oleic acid ligands, the PL quantum yield increased to 85.06%. The CuInS(2)/ZnS QD powder thermal stability results showed that the PL intensity of the QDs remained 91% at 100°C for 10 min. High color rendering index values (CRI, 90) and correlated color temperature of 4360 K for the efficient WLEDs were fabricated using CuInS(2)/ZnS QDs and (Ba,Sr)(2)SiO(4):Eu(2+) as color converters in combination with a blue GaN light-emitting diode chip.