Research Projects

The study focuses on exploring emissive organic chromophores/Europium complexes for organic electronics, particularly deep blue emitters with a Commission Internationale de l'Eclairage (CIE) value less than 0.1. Organic chromophores with donor-acceptor structures are attractive alternatives for phosphorescent metal complexes-based blue emitters due to their diverse structures, tunable photophysical properties, and usefulness in OLED applications. One effective alternative is TADF-based OLEDs, which combine electron donor and acceptor moieties in a large torsion angle to create molecules with a smaller energy gap between s1 and T1 states. To achieve deep blue emission with an appropriate CIE value, the electron-donor and acceptor units must be carefully harmonized. The frontier molecular orbitals (FMOs) of the TADF emitter are highly localized on the donor and acceptor moieties, and the donor moiety determines the HOMO and LUMO levels. By computational methods like density functional theory and time-dependent density functional theory (TD-DFT), an approximate band gap can be calculated, leading to desired deep blue emitters with an appropriate CIE value (CIEy less than 0.1). The proposal aims to promote a chromophore with a close energy gap between s1 and T1, which can aid in harvesting unutilized dark triplet excitons to singlet excited states, improving excitons utilization efficiency (EUE). The study of the D-A-D system, photophysical and electrochemical properties, electronic structure, and energy level location using TD-DFT is also being conducted. This approach holds great promise for developing ultra-deep blue luminescent materials with standard CIE values.