Small-molecule based thermally activated delayed fluorescence materials with dual-emission characteristics

Organic thermally activated delayed fluorescence (TADF) emitters have attracted increasing concerns, owing to their atypical photophysical features that can pave the way to the innovative engineering applications. As cutting-edge type of luminescent molecules, however, most of them only exert a single-wavelength emission from the lowest excited state, according to Kasha’s rule. To develop their potential applications in multicolor luminescence and multi-functional luminescent probes for biological imaging, researchers have begun to turn their attention to design organic TADF molecules with dual-emission characteristics, by employing an additional fluorescence, phosphorescence, or TADF signal within a single-component system. We herein summarized the design principles as well as the luminescence mechanism of organic donor-acceptor TADF compounds with dual-emission characteristics, the superiority of which can cover unique material applications in modern luminescence-related fields.