Advances in Pure Organic Mechanoluminescence Materials

Mechanoluminescence (ML) is the production of light from materials in response to the external stimulus of mechanical action. For organic compounds, the production of ML is tightly associated with fracture and plastic deformation of materials with piezoelectric effect in crystal lattice, and the ML property is highly dependent on the molecular packing mode, spatial conformation, and intermolecular interaction in the solid state. In the past few years, our group focused on the molecular design of pure organic ML compounds, with an attempt to discover different features of ML in pursuing the inherent emission mechanism and potential practical applications. We successfully found polymorph-dependent ML, ML with a phosphorescent property, conformation-dependent ML, ML with odd–even effect, wearable ML devices applied in heartbeat and pressure detection, etc. In this Perspective, we aim to deepen the understanding of ML and provide some guidance for the molecular design of organic light-emitting materials through the combination of our contributions.