Spiro-Fluorene Locked Multi-Resonance Emitters Enabling High-Performance Pure-Green OLEDs With CIEy Coordinate of 0.77.

) of 167 h in a stable device structure. More importantly, the state-of-the-art CIEy coordinates of 0.76-0.77 are demonstrated over 1-10 wt% broad doping range, representing the first bottom-emitting green OLED with a CIEy value reaching 0.77, and the closest to the BT.2020 green standard reported to date.