Boron-based TADF emitters with improved OLED device efficiency roll-off and long lifetime

Add time:07/13/2019    Source:sciencedirect.com

A class of four-coordinate boron complexes is reported that contain both electron-rich and electron-poor functional groups. Judicious selection of donor and acceptor moieties with the use of a boron atom as a separating node yields charge transfer complexes capable of thermally activated delayed fluorescence (TADF). Complexes were prepared by a modular method providing access to a wide range of emission colors. The singlet (S1) and triplet (T1) energies are independently tuned to achieve a small S1-T1 gap. Raising and lowering of S1 and T1 states can be predicted using cyclic voltammetry, NTO analysis, and spin density distribution as determined using Density Functional Theory; separation of the hole and electron wavefunction for S1 excitation and delocalization of spin density distribution in the T1 state can help in achieving negligible S1-T1 gap. Although photoluminescent quantum yields of the boron complexes in a host matrix are less than 65%, OLED device external quantum efficiencies of up to 8.1% have been achieved at a luminance of 1000 cd/m2. Selection of a boron emitter with a gap of less than 0.01 eV between the singlet and triplet excited state enables the fabrication of a device with low efficiency roll-off and long lifetime.

We also recommend Trading Suppliers and Manufacturers of B-(5-Methyl-1H-Pyrazol-3-Yl)Boronic Acid (cas 1163248-54-1). Pls Click Website Link as below: cas 1163248-54-1 suppliers

Prev:Metal-free allylation of electron-rich heteroaryl boronic acids with allylic alcohols
Next:Synthesis and structure‑activity‑relationship of 3,4‑Diaryl‑1H‑pyrrolo[2,3‑b]pyridines as irreversible Inhibitors of mutant EGFR‑L858R/T790M)