Structural Homology Allows Alloyed II-V Magic-Sized Clusters with Continuously Tunable Emission.

Magic-sized clusters are atomically precise nanoparticles that eliminate heterogeneous broadening, thereby enabling narrow ensemble emission. However, the discrete structural stability that causes only certain-sized clusters to exist also inherently disallows continuous optoelectronic tunability. New strategies are required to allow magic-sized clusters to continuously cover regions of the visible spectrum. Herein, we investigate the atomic structures of two oleate-ligated Cd3P2-450 and Cd3As2-525 clusters and conclude that they are structurally homologous based on pair distribution function analysis. The structural similarities between Cd3P2-450 and Cd3As2-525 allow alloying of P and As in these magic-sized clusters without perturbing the structure or the impressive optical properties. Ligand exchange for phosphinate then produces Cd3P2-xAsx magic-sized clusters with continuously tunable, narrow, and bright emission from blue (λmax = 469 nm) to green (λmax = 550 nm).