Abstract
The widespread use of Organic light emitting diode (OLED) is driven by their self-emission, vivid colours, and efficiency, while achieving optimal TADF performance requires specific molecular characteristics such as low energy gap (ΔEST) and strong conjugation. In this work, we have utilized pyrazino[2,3-f][1,10]phenanthroline due to its higher conjugation and stabilization of LUMO. Three D-π-A-π-D type skeleton thermally activated delayed fluorescence (TADF) molecules 2,3-bis(4-(3,6-di-tert-butyl-9H-carbazol-9-yl) phenyl) pyrazino[2,3-f] [1,10] phenanthroline (tCz-DPPN), 2,3-bis(4-(9,9-dimethylacridin-10(9H)-yl) phenyl) pyrazino[2,3-f] [1,10] phenanthroline (Ac-DPPN), and 2,3-bis(4-(10H-phenoxazin-10-yl) phenyl) pyrazino[2,3-f] [1,10] phenanthroline (PXZ-DPPN) were synthesized and showed higher thermal stability. Photophysical studies of these compounds showed emission in the expected range, showing wonderful colour tuning due to different donors, hence having the potential to achieve a wide range of colors. These compounds possess high thermal stability and is suitable for device fabrication via vapour deposition.
