Mechanoluminescence of Molecular Aggregates

Mechanoluminescence (ML) refers to the process by which materials emit light in response to external mechanical stimuli, offering a unique approach to challenges in stress sensors, damage detection, displays, and biological imaging, among other fields. To date, significant progress has been achieved in inorganic ML materials, both in terms of mechanism elucidation and practical applications. In contrast, the development of organic ML materials has been relatively slow, primarily due to their complex emission mechanism and lack of systematic molecular design strategies. In recent decades, studies have verified that the molecular arrangement, spatial conformation, and intermolecular noncovalent interaction exert profound influences on the luminescent properties of organic emitters. Furthermore, enhanced intersystem crossing induced by specific molecular packing modes enables phosphorescent ML in the solid state. In this chapter, we briefly summarize advances in organic ML research, organized into five sections: ML mechanisms, fluorescent ML, phosphorescent ML, ML in doped systems, and special ML phenomena.