Ding Dongxue, Wang Zicheng, Duan Chunbo, Han Chunmiao, Zhang Jing, Chen Shuo, Wei Ying, Xu Hui
Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, China.
Research (Wash D C). 2022 Dec 19;2022:0009. doi: 10.34133/research.0009. eCollection 2022.
Energy-efficient lighting sources are desired to provide another solution of carbon emission reduction. White organic light-emitting diodes are promising, because of theoretical internal quantum efficiencies for 100% electric-to-light conversion. However, pure organic fluorescent materials still face a challenge in harvesting triplet excitons for radiation. Herein, we report a white fluorescent organic light-emitting diode having an external quantum efficiency of 30.7% and a power efficiency of 120.2 lm W. In the single emissive layers, we use blue thermally activated delayed fluorescent emitters to sensitize a yellow fluorescent emitter. Transient photoluminescence and electroluminescence analyses suggest that a blue thermally activated delayed fluorescent molecule with ~100% reverse intersystem crossing efficiency and negligible triplet nonradiative rate constant completely converts triplet to singlet, suppressing triplet quenching by a yellow fluorescent emitter and ensuring 100% power conversion.
人们期望节能照明源能提供另一种减少碳排放的解决方案。白色有机发光二极管很有前景，因为其理论内部量子效率可实现100%的电光转换。然而，纯有机荧光材料在捕获三线态激子用于辐射方面仍面临挑战。在此，我们报道了一种白色荧光有机发光二极管，其外量子效率为30.7%，功率效率为120.2 lm/W。在单一发射层中，我们使用蓝色热激活延迟荧光发射体来敏化黄色荧光发射体。瞬态光致发光和电致发光分析表明，具有约100%反向系间窜越效率且三线态非辐射速率常数可忽略不计的蓝色热激活延迟荧光分子能将三线态完全转换为单线态，抑制黄色荧光发射体对三线态的猝灭，并确保100%的功率转换。
