Optoelectronic properties study of arylamine-functionalized benzothiophenes and benzothiophene S,S-Dioxides. Application in solution-processed organic light-emitting diodes

Conjugated organic molecules based on core benzothiophene (BT) and benzothiophene S,S-dioxide (BTO), substituted with triphenylamines at positions 3,5,6 and 2,4,7, were designed via Suzuki couplings. Optoelectronic properties were studied, and theoretical calculations were carried out to understand the structured absorbance spectra of the various compounds. All compounds exhibited bright emission within the visible region, ranging from blue for BT to yellow-orange for BTO. Organic light-emitting diode (OLED) devices were fabricated through an air-processed spin-coating method where all layers, except the top cathode, were solution-processed. Device luminance exceeded 1000 cd/m² using 2,4,7-triphenylaminebenzothiophene S,S-dioxide, which in turn was successfully translated to a large-area module slot-die coated on a plastic substrate.