A Real‐Time In Situ Demonstration of Direct and Indirect Transformation Pathways in CdTe Magic‐Size Clusters at Room Temperature

Abstract The transformations of colloidal semiconductor magic‐size clusters (MSCs) are expected to occur with only discrete, step‐wise redshifts in optical absorption. Here, we challenge this assumption presenting a novel, conceptually different transformation, for which the redshift is continuous. In the room‐temperature transformation from CdTe MSC‐448 to MSC‐488 (designated by the peak wavelengths in nanometer), the redshift of absorption monitored in situ displays distinctly continuous and/or step‐wise behavior. Based on conclusive evidence provided by real‐time experiments, the former transformation is apparently direct and intra‐cluster with a relatively large energy barrier. The latter transformation is indirect and assisted by MSC precursor compounds (PCs). The former transformation follows the latter often, being predominant at a relatively high temperature. The present findings encourage a reconsideration of the absorption redshift reported previously for transformations of binary II–VI MSCs, together with the pathway associated without the increase of cluster mass.