Chem
ArticleStructure of a subnanometer-sized semiconductor Cd14Se13 cluster
The bigger picture
The size-controlled colloidal semiconductor nanocrystals promise applications in optoelectronics and catalysis. However, the atomic-level understanding of the evolution of the properties of nanocrystals is still lacking, largely due to challenges in the synthesis of atomically monodisperse nanocrystals and subsequent structural characterization. In this work, by the judicious choice of a tertiary diamine ligand, we have synthesized a single-sized Cd14Se13 cluster, the first example of a nearly stoichiometric semiconductor cluster. Its single-crystal structure reveals a nonsupertetrahedral arrangement of CdSe, which is in sharp contrast to the typical supertetrahedral structure of CdSe quantum dots. Furthermore, growth and size-conversion pathways of Cd14Se13 and Cd34Se33 clusters are mapped out. The Cd14Se13 cluster is found to be susceptible to site-specific Mn substitution, forming atomically precise dilute magnetic semiconductors for futuristic applications.