Synthesis, aggregation-induced emission and electroluminescence of new luminogens based on thieno[3,2-b]thiophene S,S-dioxide

Organic luminescent materials with high fluorescence efficiencies in the solid state are highly desired in OLED devices. In this work, we report the synthesis and characterization of a series of novel dipolar luminogens based on thieno [3,2-b]thiophene S,S-dioxide (TTDO). The crystal structures, photophysical property, thermal stability, electronic structures and electrochemical behaviors of these TTDO-based luminogens are investigated. These luminogens have good aggregation-induced emission (AIE) property with high solid-state fluorescence quantum yields, and their emission wavelengths are tuned from green to red by different electron-donating substituents. They enjoy high thermal and morphological stabilities and have low LUMO energy levels. Nondoped OLEDs are fabricated with these new luminogens, providing orange to red electroluminescence (568–610 nm) with maximum external quantum efficiencies of up to 2.79%. These results demonstrate that these new AIE-active luminogens could be promising candidates for OLEDs.