Aggregation-induced emission (AIE) luminogens are a kind of unique luminescent materials with aggregation-enhanced photoluminescence quantum efficiency and photostability, which may work as ideal candidates to prepare NIR-II emissive nano contrast agents with high brightness and superior photostability . It is worthy to note that the brightness of a luminogen mainly depends on the production of the molecular absorptivity and photoluminescence quantum yield (PLQY) . However, current molecular design of AIEgens mostly requires the introduction of highly twisted molecular rotors to avoid the strong intermolecular interaction-caused luminescence quenching effect, which unfortunately usually results in a relatively lower molar absorptivity .