A comparison of the photophysical properties of thiolate-capped CdS quantum dots with thiolate-capped CdS molecular clusters

In the last several years, great advances have been made in the ability to synthesize semiconductor quantum dots with very narrow size distributions. Here, we report the synthesis of a series of thiolate-capped CdS quantum dots having reasonably narrow size distributions and make optical property comparisons to the crystallographically defined CdS molecular clusters having essentially "zero" size distribution. These clusters contain a "Cd₁₀S₄" core and thiolate/halide capping ligands. The luminescence of the molecular clusters, like the nanoparticles, is greatly influenced by the nature of the capping ligands. Additionally, the luminescence of the molecular clusters can be quite similar to that observed for their larger quantum dot counterparts.