講演情報
[7a-N304-2]Exciplex Driven Hyperfluorescence and High Efficiency Blue TADF OLED
〇(P)Debasish Barman, Chihaya Adachi
キーワード：
Thermally Activated Delayed Fluorescence、Blue Organic Light Emitting Diode、Exciplex
Multi-resonant (MR) emitters and exciplex-based thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have emerged as a promising technology for achieving high-efficiency organic light-emitting diodes. Recently, we reported a design strategy that achieves nearly 100% triplet harvesting by combining a high-polarity host matrix with highly symmetrical, horizontally aligned multi-resonant MRCT-type TADF molecules and advanced multi-stack device engineering. This synergy has enabled us to achieve a high external quantum efficiency (EQE) of over 40% in blue organic light-emitting diodes (OLEDs). However, the present work introduces a new direction in exciplex-driven hyperfluorescent TADF blue OLEDs. Considering the complementary advantages of reported exciplex systems, we developed a charge-transfer-based blue exciplex using a carbazole donor and a bipyrimidine acceptor, given their similar high triplet energy levels. The newly developed blue exciplex system demonstrates suitability as a sensitizer for blue TADF and narrowband MR emitters. Thus, this exciplex system facilitates long-range interfacial energy transfer to the ternary hyperfluorescent emissive layer in multi-stacked devices, thereby enhancing overall OLED performance. This advanced exciplex-driven device engineering is expected to enhance device performance further and enable new functionalities.