Large-Scale Programmable Synthesis of PbS Quantum Dots.

The most common method of synthesizing colloidal quantum dots (QDs) relies on an increasing particle size through increasing reaction time. We demonstrate a synthesis where the QD size is programmable through the use of a secondary phosphine sulfide precursor. The reaction runs to thermodynamic completion, resulting in a desired PbS diameter for a given set of specific reaction conditions, with no need for reaction quenching or post-synthesis size-separation. Moreover, this method is shown to produce high-quality PbS QDs on the grams scale.