Photo-induced phosphorescence and mechanoluminescence switching in a simple purely organic molecule

A simple organic molecule, 2-(9H-carbazol-9-yl)ethanol (CZEO), displays both mechanoluminescence (ML) and photo-induced room-temperature phosphorescence (RTP). The D–A type dimer formed in the crystals was found to play a crucial role in the light-stimulated luminescent response, responsible for the turn-on RTP and turn-off ML switching of CZEO.