Triplet excitons play an important role in the physics of organic emitters used in organic light-emitting diodes, bio-imaging, and security inks. Triplet exciton dynamics is influenced by the emitters and the environment surrounding them, but there is no effective way to alter triplet dynamics using external triggers. Here we demonstrate rapid and reversible control of the triplet dynamics of the emitter coronene via an external heavy-atom effect induced by external gases. Strong interaction between the emitter molecule and gases is achieved by encapsulating the emitter in a metal organic framework. Exposure to xenon, which has a large spin-orbit coupling, accelerates the radiative decay of triplets, leading to a stronger phosphorescence that decays more quickly than under vacuum. By contrast, excitons can be non-radiatively quenched through exposure to oxygen. This fast and reversible regulation of triplet dynamics may provide a new platform for responsive photo-switches, optical storage, and molecular computers.
All Science Journal Classification (ASJC) codes
- Materials Chemistry
- Environmental Chemistry