TDBA-SAF is deep blue multiple resonance thermally activated delayed fluorescence (MR-TADF) emitter with oxygen-bridged triaryl-boron core (DOBNA) as electron acceptor unit and spiro[acridine-9,9'-fluorene] as the electron donor unit. Due to the rigid donor and acceptor units, TDBA-SAF exhibits narrow emission spectrum with the FWHM of less than 65 nm. The extended molecular structure along the transition dipole moment direction results in a highly horizontal emitting dipole ratio over 80%. Deep blue TADF-OLED based on TDBA-SAF as the dopant and DPEPO as the host exhibits a maximum EQE of 28.2% and CIE coordinates of (0.142, 0.090).
Also, TDBA-SAF can be employed as the sensitizer in hyperfluorescence devices. Deep blue hyperfluorescence TADF (HF-TADF) device based on Tp-DABNA as the emitter and TDBA-SAF as the sensitizer demonstrates great device performance with an EQEmax of 28.7 % and mitigated efficiency roll-offs.