Aggregation-induced emission (AIE): emerging technology based on aggregate science

Functional materials serve as the basic elements for the evolution of technology. Aggregation-induced emission (AIE), as one of the top 10 emerging technologies in chemistry, is a scientific concept coined by Tang, et al. in 2001 and refers to a photophysical phenomenon with enhanced emission at the aggregate level compared to molecular states. AIE-active materials generally present new properties and performance that are absent in the molecular state, providing endless possibilities for the development of technological applications. Tremendous achievements based on AIE research have been made in theoretical exploration, material development and practical applications. In this review, AIE-active materials with triggered luminescence of circularly polarized luminescence, aggregation-induced delayed fluorescence, room-temperature phosphorescence, and clusterization-triggered emission at the aggregate level are introduced. Moreover, high-tech applications in optoelectronic devices, responsive systems, sensing and monitoring, and imaging and therapy are briefly summarized and discussed. It is expected that this review will serve as a source of inspiration for innovation in AIE research and aggregate science.