Benzoselenadiazole-based donor-acceptor small molecule: Synthesis, aggregation-induced emission and electroluminescence

Several tetraphenylethene and triphenylamine decorated donor-acceptor (D-A) benzoselenadiazole derivatives with aggregation-induced emission (AIE) features were synthesized and characterized. The photophysical, thermal, electrochemical and electroluminescent (EL) properties, as well as the AIE property of the resulting luminogens are discussed. All the luminogens are soluble in common organic solvents and show high thermal stability with a T_d of 399–460 °C. The absolute photoluminescence quantum yield in the solid state ranged from 14.2% to 36.5%. The D–A structures of TPE-Se-TPE, TPA-Se-TPE and TPA-Se-TPA enable them to have aggregation-caused quenching (ACQ) plus aggregation-induced emission enhancement (AIEE) effects dominated by the twisted intramolecular charge-transfer (TICT) and restriction of intramolecular rotations (RIR), respectively. The best device performances were obtained from TPA-Se-TPE with a maximal luminous efficiency of 2.91 cd/A and the maximal brightness is 5855 cd/m². This is the first report of benzoselenadiazole-based fluorophore with an AIE feature for organic electronics application.