Theoretical Investigations of the Photophysical Properties of Star-Shaped π-Conjugated Molecules with Triarylboron Unit for Organic Light-Emitting Diodes Applications

The density functional theory (DFT) and time-dependent DFT (TD-DFT) methodologies have been applied to explore on a series of star-shaped π-conjugated organoboron systems for organic light-emitting diode (OLED) materials. The compounds under investigation consist of benzene as π-bridge and different core units and triarylboron end groups. Their geometry structures, frontier molecular orbital (FMO) energies, absorption and fluorescence spectra, and charge transport properties have been investigated systematically. It turned out that the FMO energy levels, the band gaps, and reorganization energies optical are affected by the introduction of different core units and triarylboron end groups. The results suggest that the designed compounds are expected to be promising candidates for luminescent materials. Furthermore, they can also serve as hole and/or electron transport materials for OLEDs.