A meta-linked benzoxazole-based wide-bandgap material for deep-blue electroluminescence and high-brightness, low-roll-off multicolor phosphorescent OLEDs

) and significantly suppressed roll-offs. These performances surpass those of conventional hosts such as CBP and mCP. The superior device characteristics originate from efficient Förster/Dexter energy transfer, suppressed triplet exciton annihilation, and inhibited back energy transfer enabled by the high triplet energy. This work provides an effective molecular design strategy toward high-efficiency, low-roll-off, and full-color OLEDs.