Multicolor Light-Emitting Diodes with MoS2 Quantum Dots

Molybdenum disulfide (MoS 2 ) quantum dots (QDs) are known for their excitation-wavelength-dependent photoluminescent (PL) properties. However, the mechanism of this phenomenon is still unclear. Here, small size MoS 2 QDs with a narrow size distribution are synthesized. Based on the decay study and PL dynamics, a reasonable radiation model is presented to understand the special PL properties, i.e., the carrier recombination in the localized surface defect states generated the PL. Accordingly, this optical property is used to fabricate multicolor light-emitting devices with the same MoS 2 QDs. The emission color covers the full visible spectrum from blue to red, only by adjusting the thickness of the down-conversion QD layers.