The lifetime of triplet state of molecular materials is generally shorter than 1 ms at room-temperature (RT) because nonradiative deactivation of the triplet state is usually rapid at RT. However, if the fast nonradiative deactivation from the triplet state is largely suppressed, triplet excitons with a very long lifetime at RT can form. Molecular materials with the long exciton lifetimes could potentially lead to the realization of new applications that are unfeasible using conventional molecular materials with short exciton lifetimes.
Shuzo Hirata, Materials science using ultralong-lived room-temperature triplet excitons: Molecular persistent room-temperature phosphorescence and nonlinear optical characteristics under continuous irradiance, Journal of Materials Chemistry C, 2018.
Digital Object Identifier (DOI): 10.1039/C8TC01417E