Elastic organic crystals with ultralong phosphorescence for flexible anti-counterfeiting

Abstract Ultralong organic phosphorescence (UOP) crystals have attracted increased attention due to the distinct photophysical property of a long-lived lifetime. However, are generally brittle, leading serious problem for their application in flexible technology. Herein, we report three types elastic (EOCs) with ultralong via introducing halogen atoms (Cl, Br, I) into π-conjugated phosphorescent molecules. Especially, crystal containing iodine displayed both excellent elasticity ( ε = 3.01%) and high efficiency Φ Ph 19.1%) owing strong bonds. Taking advantage its highly efficient UOP elasticity, successfully used DCz4I anti-counterfeiting application. These findings may provide guidance development afterglow expand scope potential applications on materials.