Computational-assisted molecular design, synthesis and application of benzobisthiadiazole-based near-infrared dye in electrowetting displays†

Electrowetting display (EWD) technology is among the most promising reflective display technologies due to its full-color capabilities and fast video-speed performance. The colored EWD inks are typically prepared by dissolving soluble organic dyes in non-polar solvents, which significantly influence the color performance, electro-optical behaviour, and longevity of EWD devices. In this study, density functional theory (DFT) at the PBE1PBE/6-31G* level and time-dependent density functional theory (TD-DFT) at the M06-2X/6-31G* level were utilized to calculate a series of benzobisthiadiazole-based donor–acceptor–donor (D–A–D) type near-infrared organic dyes for EWDs, providing structural and spectral data to aid in spectral assignment. The quantum chemical calculations' results align with our experimental synthesis data, showing molecular colors spanning blue, green, and cyan. Detailed investigations into the properties of these dyes, including absorption, electro-optical response, and photo-stability, were conducted. The experimental outcomes indicate that these organic dyes are excellent candidates for EWD applications.