Time-resolved photoluminescence study of an aggregation-induced emissive chromophore

The photophysical properties associated with the aggregation-induced emission of hexaphenyl-silole (silole) in an acetone/water mixture were studied by using a fluorescence decay lifetime measurements. The fluorescence decay lifetime of silole in a pure acetone solution was very short and was barely resolved from the instrumental response function (∼150 ps) of the time-correlated single photon counting system. When water as a poor solvent was added to the silole solution, the photoluminescence (PL) intensity was significantly enhanced above 60% of the water fraction compared to the pure acetone solution, and the PL decay lifetime increased up to a value of ∼-4 ns. These results confirmed the formation of silole nanoparticles in the solution of water mixture, which restricted the intramolecular rotational motion of the phenyl rings linked to silole center, reduced the nonradiative decay process of silole chromophore, and led to an increase in the PL decay lifetime and the quantum efficiency.