Efficient narrowband electroluminescence based on a hetero-bichromophore thermally activated delayed fluorescence dyad

Abstract

A hetero-bichromophore thermally activated delayed fluorescence (TADF) emitter named BOQAO was designed and synthesized, which consists of two multi-resonance TADF (MR-TADF) core tBuBO and tBuQAO. The short-range intramolecular charge transfer...

Merging Boron and Carbonyl based MR‐TADF Emitter Designs to Achieve High Performance Pure Blue OLEDs**

“…As shown in Figure S17, there is an irreversible oxidation and a quasi‐reversible reduction wave, with associated peak potentials from the DPV of 1.47 and −1.50 eV, respectively. The corresponding HOMO and LUMO levels are −5.78 and −2.80 eV, respectively, leading to an intermediate HOMO–LUMO gap of 2.98 eV compared to those tBuDOBNA (3.00 eV) and tBuDiKTa (2.85 eV) [25] . The room temperature UV/Visible absorption, steady‐state photoluminescence (PL) and 77 K phosphorescence spectra of DOBDiKTa in dilute toluene solution are depicted in Figure 3.…”

“…The corresponding HOMO and LUMO levels are À 5.78 and À 2.80 eV, respectively, leading to an intermediate HOMO-LUMO gap of 2.98 eV compared to those tBuDOBNA (3.00 eV) and tBuDiKTa (2.85 eV). [25] The room temperature UV/Visible absorption, steady-state photoluminescence (PL) and 77 K phosphorescence spectra of DOBDiK-Ta in dilute toluene solution are depicted in Figure 3. The absorption spectrum possesses three distinguished peaks at 335, 374 and 429 nm (Figure 3a).…”

Carbonyl‐Containing Thermally Activated Delayed Fluorescence Emitters for Narrow‐Band Electroluminescence

“…In 2022, our group reported a QAO derivative named BOQAO, which is consist of tert ‐butyl‐modified MR core tBuQAO and tBuBO [44] . Such a unique molecular skeleton leads to a weak long‐range ICT from tBuQAO to tBuBO, which maintains the narrow‐band profile with a slight redshift (7 nm) for BOQAO in dilute toluene solution compared with the emission spectra of the parent segment tBuQAO.…”

High-efficiency deep-red to near-infrared emission from Pt(ii) complexes by incorporating an oxygen-bridged triphenylborane skeleton

“…The oxygen(O)-bridged and boron(B)-embedded polycyclic skeletons (BOs) have been widely used to construct materials with multiple-resonance-thermal activation-delayed fluorescence (MR-TADF) due to their symmetrical planar geometry, good electrontransporting capability and easy structure modification. [42][43][44][45][46][47][48] For example, a TDBA-DI emitter with a BO skeleton was reported to exhibit blue emission with a high EQE of 38.15% and a low efficiency roll-off. 43 Other applications were recently reported to construct phosphorescent Ir(III) complexes, which can reduce the vibrational relaxation of the complexes by hindering the vibration and rotation of the ligands, further decreasing the non-radiative loss.…”