Full-Color, Narrowband, and High-Efficiency Electroluminescence from Boron and Carbazole Embedded Polycyclic Heteroaromatics

Herein,
we demonstrate that the strategic implementation of electron-accepting
tricoordinate boron and electron-donating carbazole subunits into
polycyclic aromatic hydrocarbons (PAHs) produces a family of attractive
full-color luminophores that can emit narrowband and efficient thermally
activated delayed fluorescence (TADF). A versatile modular design
for these boron- and carbazole-embedded PAHs can facilitate the systematic
modulation of their photophysical and optoelectronic properties. Organic
light-emitting diodes that utilize these PAHs as TADF emitters demonstrate
narrowband electroluminescence from blue to red, achieving high maximum
external quantum efficiencies of 29.3%, 31.8%, and 22.0% for blue,
green, and red, respectively.