DABNA-1 has a rigid polycyclic aromatic framework containing a triphenyl boron core and two nitrogen atoms that are connecting all five phenyl rings. Structurally, DABNA-1 also can be considered as two triphenyl amines that has one common phenyl ring which is joined by two other neighbouring phenyl rings with a boron to form a triphenyl boron central core. DABNA-1 was one of the first developed multi-resonance thermally activated delayed fluorescence (MR-TADF) materials containing one boron atom and two nitrogen atom with boron and nitrogen exhibiting the opposite resonance effect.
DABNA-1 exhibited deep blue emission with photoluminescence quantum efficiency (PLQY) and singlet–triplet energy splitting (ΔEST) of 0.88 and 0.18 eV in 1 wt.% doped mCBP film. Deep blue OLED devices based on DABNA-1 showed high efficiency with an EQE value of 13.5% and a color coordinate of (0.13, 0.09), along with high color purity of very narrow EL spectra full width at half maximum (FWHM) of 28 nm at 459 nm. Though showing high efficiency roll-off, DABNA-1 and its derivatives are promising candidates for developing high color purity, high efficiency deep blue TADF-OLEDs.
Other MR-TADF materials containing DABNA-1 core such as t-DABNA, v-DABNA and 3tPAB are also available.