We showed that dimerizing the MR-TADF emitter, DiKTa, in DDiKTa, leads to modest red-shift of the emission and the OLED showed an improved performance. In an attempt to further improve the device performance and reduce the structural motion inherent in DDiKTa, here we envisioned annealing together two DiKTa units through a central 9,9-dimethyl-9H-fluorene bridge, DDiKTa-F. The analogue without the tertbutyl groups was also synthesized, but purification proved too difficult owing to its poor solubility, likely due to its strong propensity to aggregate. Therefore, two tertbutyl groups were added to improve the solubility of this compound. DDiKTa-F was found to be brighter (photoluminescence quantum yield, FPL, of 78%) and emits with a narrower full width at half maximum, FWHM, of 49 nm compared to DDiKTa (FPL of 68 % and FWHM of 59 nm) in 2 wt% doped films in mCP. The device with DDiKTa-F showed an EQEmax of 15.3% emitting at lEL of 493 nm (FWHM of 46 nm) and showing an improved efficiency roll-off at 100 cd m -2 of 35% compared to the devices with DDiKTa (56%) and DiKTa (44%).