Room temperature luminescence of a triangulenium dye ADOTA in PVA films

The luminescence properties of the cationic triangulenium dye ADOTA embedded in poly(vinyl alcohol) (PVA) were investigated over a broad range of temperatures. We observed extremely efficient delayed fluorescence (DF) with a lifetime of approximately 160 ms. The spectral characteristics of the DF closely match those of the prompt fluorescence. The temperature-dependent emission intensity of ADOTA’s delayed fluorescence reaches a maximum at about 30 oC. This observation reveals for the first time presence of a triplet state T1 in triangulenium dyes. Significant intensity and high anisotropy of ADOTA’s DF in time gated detection format offers access to molecular dynamics from micro to millisecond range, in both spectroscopic and microscopic investigations.