Luminogens with aggregation-induced emission (AIEgens) have been widely applied in the field of photodynamic therapy. Among them, aggregation-induced emission photosensitizers (AIE–PSs) are demonstrated with high capability in fluorescence and photoacoustic bimodal imaging, as well as in fluorescence imaging-guided photodynamic therapy. They not only improve diagnosis accuracy but also provide an efficient theranostic platform to accelerate preclinical translation as well. In this short review, we divide AIE–PSs into three categories. Through the analysis of such classification and construction methods, it will be helpful for scientists to further develop various types of AIE–PSs with superior performance.

A highly emissive chalcone crystal which displays fantastic photo-induced jumping behavior is designed and the microscopic dynamic process is easily visualized and captured. The motion mechanism is demonstrated to be a [2+2] cycloaddition reaction.

Self-assembled mono- and bi-nuclear complexes of Cd(II) (1), Co(II) (2), Zn(II) (3), Ni(II) (4) and Cu(II) (5) were synthesized via the reaction of 5-methyl-1-(4-carboxylphenyl)-1H-1,2,3-triazole-4-carboxylic acid (H₂L) and the corresponding metal salt under hydrothermal conditions. All complexes were characterized using elemental analysis, IR spectroscopy, UV-vis spectroscopy, PXRD analysis, thermogravimetry and single-crystal X-ray diffraction. Structural analyses show that the H₂L ligand exhibits diverse coordination modes: μ₂-η¹ _O-η¹ _O-η¹ _O-η¹ _N for 1, μ₂-η¹ _O-η¹ _O-η¹ _N for 2–4 and μ₃-η¹ _O-η¹ _O-η¹ _N-η¹ _O for 5. Based on the various structures and the luminescent response of xanthine (3,7-dihydro-purine-2,6-dione), a new experiment for exploring the interaction between transition metal complexes and luminescent xanthine was performed for the first time. The results show that the luminescence response of xanthine depends on the concentration of metal complex.

Organic light-emitting diodes (OLEDs) have attracted remarkable interest in display and lighting. To effectively address triplet exciton harvesting and enhance external quantum efficiency (EQE), delayed fluorescence AIEgens have gained significant prominence. The primary luminescence mechanism involves the efficient harvesting of triplet excitons via reverse intersystem crossing (RISC) channels, categorized into three types: thermally activated delayed fluorescence (TADF), hybridized local and charge transfer (HLCT), and triplet–triplet annihilation (TTA). In this review, we summarize the recent development of doped and non-doped delayed fluorescent AIEgens-based OLEDs. This review mainly discusses the molecular design strategies and photophysical properties of delayed fluorescent AIEgens and the electroluminescent properties of OLEDs as emitting layers. Finally, the challenges and prospects of delayed fluorescent AIEgens for the fabrication of OLEDs are also briefly discussed.