Colloidal PbS Nanocrystals with Size‐Tunable Near‐Infrared Emission: Observation of Post‐Synthesis Self‐Narrowing of the Particle Size Distribution

The synthesis of nanocrystalline PbS quantum dots using organometallic precursors is reported. The samples exhibit tunable, strong near‐infrared photoluminescence. A remarkable spontaneous self‐directed narrowing of the particle size distribution is shown to occur after the particles are synthesized and dispersed in organic solvent. The Figure shows the tuning of band‐edge exciton absorption features through the near‐infrared spectral region according to particle size.