Bian Jinkun, Chen Su, Qiu Lili, Zhang Nan, Zhang Jing, Duan Chunbo, Han Chunmiao, Xu Hui
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, China.
Research (Wash D C). 2022 Jun 2;2022:9838120. doi: 10.34133/2022/9838120. eCollection 2022.
Multiresonance (MR) emitters featuring narrowband emissions and theoretically 100% exciton harvesting are great potential for organic light-emitting diode (OLED) applications. However, how to functionalize MR molecules without scarifying emission color purity is still a key challenge. Herein, we report a feasible strategy for selective optimization of MR molecules, which is demonstrated by a blue MR emitter substituted with a diphenylphosphine oxide (DPPO) group. Compared to its DPPO-free parent molecule, preserves narrowband feature with full widths at half maximum (FWHM) values of 28 nm in film and 32 nm in OLEDs and achieves 40% increased photoluminescence (92%) and electroluminescence quantum efficiencies (28%). It is showed that insulation effect of P=O effectively confines the singlet excited state on MR core to keep emission color purity, and its induction effect enhances singlet radiation and triplet-to-singlet conversion. This synergism for selective optimization is based on rational linkage between MR core and functional groups.
具有窄带发射且理论上能实现100%激子收集的多共振（MR）发光体在有机发光二极管（OLED）应用中具有巨大潜力。然而，如何在不牺牲发射色纯度的情况下使MR分子功能化仍是一个关键挑战。在此，我们报道了一种用于MR分子选择性优化的可行策略，该策略通过一个被二苯基氧化膦（DPPO）基团取代的蓝色MR发光体得以证明。与其不含DPPO的母体分子相比，其在薄膜中的半高宽（FWHM）值为28nm，在OLED中为32nm，保留了窄带特性，并实现了40%的光致发光（92%）和电致发光量子效率提高（28%）。结果表明，P=O的绝缘效应有效地将单重激发态限制在MR核心上以保持发射色纯度，其诱导效应增强了单重辐射和三重态到单重态的转换。这种用于选择性优化的协同作用基于MR核心与官能团之间的合理连接。
