Preparation and Photoelectric Properties of CuInS₂/ZnS/ZnS Quantum Dots

CuInS₂-based quantum dots light-emitting diodes (QLEDs) were fabricated in three major steps.First, the CuInS₂ nuclear quantum-dots (QDs) were synthesized by one-pot reaction, next, the CuInS₂ QDs were uniformly covered with double thick ZnS shells grown one after another via chemical route under different growth conditions;and finally, QLEDs were fabricated with the CuInS₂/ZnS/ZnS QDs spin-coated on pre-patterned ITO substrate and used as the light-emission layer.The nanostructures/optical properties of CuInS₂/ZnS/ZnS QDs and photoelectric properties of QLEDs were characterized with X-ray diffraction photoluminescence spectroscopy and transmission electron microscopy.The results show that high quality QDs and QLEDs can be synthesized and fabricated bottom-up via chemical route.To be specific, the CuInS₂/ZnS/ZnS QDs had improved photoluminescence and electroluminescence properties and a quantum yield of~76%;the onset voltage and luminance of QLEDs were 2.5 V and 5473 cd/m², respectively.