Jang Hyuk Kwon

Abstract Simultaneously obtaining high efficiency and deep blue emission in organic light emitting diodes (OLEDs) remains a challenge. To overcome the demands associated with deep blue thermally activated delayed fluorescence (TADF) emitters, two deep blue TADF materials namely, DBA–BFICz and DBA–BTICz, are designed and synthesized by incorporating oxygen‐bridged boron (DBA) acceptor with heteroatoms, oxygen and sulphur‐based donors, BFICz and BTICz, respectively. Both TADF materials show deep b

Highly efficient red phosphorescent dopants in organic light-emitting devices have been explored by using a cyclometalated iridium complex with a fully methylated phenyl ring and a quinoline ring as well as a sterically crowded ancillary ligand. The red phosphorescent devices with these dopants give extremely high external quantum efficiencies.

Abstract Two new orange–red thermally activated delayed fluorescence (TADF) materials, PzTDBA and PzDBA, are reported. These materials are designed based on the acceptor–donor–acceptor (A–D–A) configuration, containing rigid boron acceptors and dihydrophenazine donor moieties. These materials exhibit a small Δ E ST of 0.05–0.06 eV, photoluminescence quantum yield (PLQY) as high as near unity, and short delayed exciton lifetime (τ d ) of less than 2.63 µs in 5 wt% doped film. Further, these mater

The subclass of multi resonant thermally activated delayed fluorescent emitters (MR-TADF) containing boron atoms has garnered significant attention in the field of organic light emitting diode (OLED) research. Among boron-based MR-TADF emitters, double boron-embedded MR-TADF (DB-MR-TADF) emitters show excellent electroluminescence performances with high photoluminescence quantum yields, narrow band emission, and beneficially small singlet-triplet energy levels in all the full-color gamut regions

Abstract The hyperfluorescence (HF) system has drawn great attention in display technology. However, the energy loss mechanism by low reverse intersystem crossing rate ( k RISC ) and the Dexter energy transfer (DET) channel is still challenging. Here, we demonstrate that this can be mitigated by the quadrupolar donor-acceptor-donor (D-A-D) type of thermally activated delayed fluorescence (TADF) sensitizer materials, DBA-DmICz and DBA-DTMCz. Further, the HF device with DBA-DTMCz and ν -DABNA exhi

for MR-TADF materials with some supportive strategies including extending charge delocalization, heavy atom introduction, multi-donor/acceptor utilization, and a hyperfluorescence system approach. Furthermore, the outlook and prospects for future developments in MR-TADF skeletons are described.

Abstract In the field of organic light‐emitting diodes, organo‐boron based thermally activated delayed fluorescence (TADF) emitters have witnessed outstanding achievements. However, it is still challenging to achieve pure blue color (CIE y < 0.20) along with high efficiencies. To overcome these hurdles, the hyperfluorescence (HF) system suggests a key strategy for future display applications. Here, two TADF host materials, p MDBA‐DI and m MDBA‐DI, and a pure blue multi‐resonance type tert‐but

Highly efficient deep blue fluorescent material and various thermally activated delayed fluorescent (TADF) blue sensitization materials were synthesized for fluorescent deep blue organic light-emitting diodes (OLEDs). These materials were designed and selected by considering efficient energy transfer conditions (i.e., spectral overlap and quantum efficiency) between sensitizer and acceptor. Energy transfer process from TADF host sensitizers to deep blue fluorescent emitter has been investigated

Abstract Thermally activated delayed fluorescence (TADF) materials have emerged as an efficient emitter for achieving high efficiency of blue organic light emitting diodes (OLEDs). However, it is challenging to satisfy both high device efficiency and long operational lifetime together. Here, highly efficient and electrochemically stable blue TADF emitter, 5‐(5,9‐dioxa‐13b‐boranaphtho[3,2,1‐de]anthracen‐7‐yl)‐10,15‐diphenyl‐10,15‐dihydro‐5H‐diindolo[3,2‐a:3′,2′‐c]carbazole (DBA‐DI) is designed an

In the last few years, electron-deficient materials have been actively researched for application in organic light-emitting diode (OLED) as dopant and electron-transporting materials. The boron-containing materials are interesting as they give good emissive properties in solid state with an electron-accepting character. Recently, many boron-containing materials are used as emissive materials for thermally activated delayed fluorescence (TADF) OLED applications. In this review, boron acceptor-bas

New highly efficient thermally activated delayed fluorescence (TADF) dopant materials (PXB-DI and PXB-mIC) for blue organic light-emitting diodes are reported. These materials were designed by combining highly conjugated rigid ring donor moieties and a boron acceptor with a highly twisted configuration to have high TADF performance and minimized self-quenching properties. In addition, a new high triplet energy and hole transport-type host material, 5-(5-(2,4,6-triiso-propylphenyl)pyridin-2-yl)-5

Abstract Developing double boron‐based emitters with extremely narrow band spectrum and high efficiency in organic light‐emitting diodes (OLEDs) is crucial and challenging. Herein, we report two materials, NO‐DBMR and Cz‐DBMR , hinge on polycyclic heteraborin skeletons based on role‐play of the highest occupied molecular orbital (HOMO) energy levels. The NO‐DBMR contains an oxygen atom, whereas the Cz‐DBMR has a carbazole core in the double boron‐embedded ν‐DABNA structure. The synthesized mater