A simple and versatile strategy for realizing bright multicolor mechanoluminescence.

Multicolor mechanoluminescence (ML) was first realized by using the stable organic blue ML emitter N-phenylcarbazole as the host matrix. It is claimed that a good ML host should have a moderate melting point and be able to dissolve or disperse organic dyes but maintain high ML activity and crystallinity. This strategy is versatile and can avoid difficult molecular design and troublesome chemical synthesis.

Touch-sensitive mechanoluminescence crystals comprising a simple purely organic molecule emit bright blue fluorescence regardless of crystallization methods.

Simple N-phenylcarbazole (NPC) could readily form brightly mechanofluorescent crystals with mechanically touch-sensitive response, regardless of crystallization methods. NPC with room-temperature photophosphorescence did not exhibit mechano-phosphorescence, signifying that the excitation modes could play an important role in affecting light-emitting processes.