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

Carbazole-based DABNA analogues (CzDABNAs) 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 CzDABNAs, exhibiting narrowband thermally activated delayed fluorescence with emission spectra ranging from deep blue to green.

Solution-Processable Pure Green Thermally Activated Delayed Fluorescence Emitter Based on the Multiple Resonance Effect.

Thermally activated delayed fluorescence (TADF) materials based on the multiple resonance (MR) effect are applied in organic light-emitting diodes (OLEDs), combining high color purity and efficiency. However, they are not fabricated via solution-processing, which is an economical approach toward the mass production of OLED displays. Here, a solution-processable MR-TADF material (OAB-ABP-1), with an extended π-skeleton and bulky substituents, is designed.

One-Shot Multiple Borylation toward BN-Doped Nanographenes.

One-shot double, triple, and quadruple borylation reactions of triarylamines were developed through a judicious choice of boron source and Brønsted base. With the aid of borylation reactions, a variety of BN-doped nanographenes were synthesized in two steps from commercially available starting materials. An organic light-emitting diode device employing BN-doped nanographene as an emitter exhibited deep pure-blue emission at 460 nm, with CIE coordinates of (0.