M2 寒河江友紀さんの「基板水平配向を促進し、凝集起因消光を抑制する、外部量子効率38.6%を実現するメシチレン修飾水色MR-TADF材料」に関する論文が英国化学会の Journal of Materials Chemistry C (IF: 5.1) に受理されました！寒河江、おめでとう！本論文は、Journal of Materials Chemistry C HOT Papers に選出されています。
本研究は、JSPS 科研費（基盤研究B 23H02032）、岩谷直治記念財団の助成を受けたものです。
Abstract: Boron-based multiresonance thermally activated delayed fluorescence (MR-TADF) emitters combine intrinsically narrowband emission with near-unity internal quantum efficiency. However, their practical implementation in OLED displays remains limited by aggregation-caused quenching, long delayed fluorescence lifetimes, suboptimal horizontal emissive transition dipole moment ratio, and poor electrical stability. Among boron-based MR-TADF systems, carbazole-based CzBN has emerged as a representative and widely studied motif due to its facile chemical modifiability, which allows for the development of diverse derivatives aimed at alleviating these limitations. Here, we present MesCzBN, a sky-blue MR-TADF emitter featuring four mesitylene groups appended to the periphery of the CzBN core. The mesitylene “umbrella” sterically shields the MR core and promotes a horizontal emissive transition dipole moment ratio of 84% and a high photoluminescence quantum yield of 100% in a carbazole-based host matrix. MesCzBN achieves an external quantum efficiency of 38.6%, a peak electroluminescence wavelength of 494 nm, and a narrow full width at half maximum of 28 nm in a hyperfluorescent device. Peripheral mesitylene modification thus provides a novel sterically wrapping strategy to enhance horizontal molecular orientation and device efficiency in OLEDs, serving as a superior replacement for the benchmark tCzBN with four tert-butyl groups.
