Bulk Assembly of Zero-Dimensional Organic Copper Bromide Hybrid with Bright Self-Trapped Exciton Emission and High Antiwater Stability

Recently, Cu(I)-based metal halides have gained great attention due to their fascinating structures and optoelectronic properties. Here, we report the synthesis, crystal structure, and photophysical properties of zero-dimensional (0D) organic copper bromide hybrid, where the isolated [CuBr2]− units are encircled by the organic cation of TBA+ (TBA+ = tetrabutylammonium cation), forming the bulk assembly of periodic 0D blocks. Moreover, this 0D structure enables strong electron–phonon interaction to promote the formation of a self-trapped excited state that shows a bright broadband cyan emission with a photoluminescence quantum yield (PLQY) of 55% for (TBA)CuBr2 single crystals (SCs). Particularly, the as-synthesized compound shows extraordinary antiwater stability, and its PL intensity remains above 99.1% after soaking in water for 24 h. This work illustrates that the water-sensitive Cu(I) can also be used as a high antiwater stability luminescent material by introducing appropriate multifunctional organic ligands, thus opening up a new route for high antiwater materials based on lead-free metal halides.