Atomically precise metal-chalcogenide semiconductor molecular nanoclusters with high dispersibility: Designed synthesis and intracluster photocarrier dynamics

A comprehensive understanding of excited-state dynamics of semiconductor quantum dots or nanomaterials at the atomic or molecular level is of scientific importance. Pure inorganic (or non-covalently protected) seimiconductor molecular nanoclusters with atomically precise structure are contributive to establish accurate correlation of excited-state dynamics with their composition/ structure, however, the related studies are almost blank because of unresolved solvent dispersion issue. Herein, we designedly created the largest discrete chalcogenide seimiconductor molecular nanoclusters (denoted P2-CuMSnS, M = In or/and Ga) with great dispersibility, and revealed an interesting intracluster "core-shell" charge transfer relaxation dynamics. A systematic red shift in absorption spectra with the gradual substitution of In by Ga was experimentally and computationally investigated, and femtosecond transient absorption measurements further manifested there were three ultrafast processes in excited-state dynamics of P2 nanoclusters with the corresponding amplitudes directed by composition variation. Current results hold the great promise of the solution-processible applications of semiconductor-NC-based quantum dots and facilitate the development of atomically precise nano-chemistry.