respectively, and achieved EQEmax values of 24.6 and 21.2%, respectively, compared to an EQEmax of 24.1% at λEL of 486 nm and CIE coordinates of (0.20, 0.36) for the device with 4CzPz. The spin-coated films of 4tCzPz and 4αCbPz in mCBP displayed ASE emission at 491 nm and 474 nm, with ASE thresholds of 41.0 µJ/cm 2 and 44.9 µJ/cm 2 , respectively, compared to ASE emission at 492 and threshold of 31.6 µJ/cm 2 for vacuum-deposited film of 4CzPZ in mCBP. Our investigation confirms that D-A TADF materials have promising prospects in serving both as emitters in OLEDs as well as in OSL.