Bluish-green-to-green thermally activated delayed fluorescent emitters based on β-diketone derivatives exhibiting a horizontal emission dipole orientation ratio of 88% and an external quantum efficiency of nearly 25%

A series of β-diketone-based TADF emitters named MCzX derivatives are designed and prepared. Among these emitters, MCzDBM exhibits a PLQY of 79%, horizontal emission dipole orientation ratio of 88%, and high EQE of approximately 25%.