Self-Assembly of Perovskite CsPbBr Quantum Dots Driven by a Photo-Induced Alkynyl Homocoupling Reaction.

Herein, we report the facile growth of three-dimensional CsPbBr perovskite supercrystals (PSCs) self-assembled from individual CsPbBr perovskite quantum dots (PQDs). By varying the carbon chain length of a surface-bound ligand molecule, 1-alkynyl acid, different morphologies of PSCs were obtained accompanied by an over 1000-fold photoluminescence improvement compared with that of PQDs. Systematic analyses have shown, for the first time, that under UV irradiation, CsBr, the byproduct formed during PQDs synthesis, could effectively catalyze the homocoupling reaction between two alkynyl groups, which further worked as a driving force to push forward the self-assembly of PQDs.