Multifunctional oxadiazole-based ultraviolet-emitting materials used as hosts for multicolor phosphorescence

-PIOXZ exhibit efficient ultraviolet electroluminescence, but it can also serve as the host material for high-efficiency phosphorescent OLEDs (PhOLEDs) with low roll-off. As a result, high external quantum efficiency (EQE) and long operational lifetimes are obtained in green, yellow and red emissive PhOLEDs, providing new insights for developing high-efficiency, low roll-off, and full-color OLEDs.