Physics

OLED

Nanotechnology

Organic chemistry

Carbazole

Optics

Catalysis

Narrowband

Chemistry

Materials science

Layer (electronics)

Diode

Optoelectronics

Regioselectivity

Photochemistry

Fluorescence

Angewandte Chemie International Edition

Carbazole‐based DABNA analogues ( CzDABNA s) were synthesized from triarylamine by regioselective one‐shot single and double borylation. The reaction proceeded selectively at the ortho position of the carbazolyl group, where the highest occupied molecular orbital is mainly localized owing to the difference in the electron‐donating abilities of the diarylamino and carbazolyl groups. The facile and scalable method enabled synthesis of CzDABNA s, exhibiting narrowband thermally activated delayed fluorescence with emission spectra ranging from deep blue to green. The organic light‐emitting diode devices employing these products as emitters exhibited deep‐blue, sky‐blue, and green emission with high external quantum efficiencies of 19.5, 21.8, and 26.7 %, respectively.

Carbazole‐Based DABNA Analogues as Highly Efficient Thermally Activated Delayed Fluorescence Materials for Narrowband Organic Light‐Emitting Diodes