摘要
有机发光二极管(OLED)已经在智能手机方面获得了商业应用,由于目前规模生产的OLED采用蒸镀工艺,使其价格居高不下。为此,我们采用溶液加工方法,使用铂配合物作为敏化剂,多重共振热激活延迟荧光材料作为发光分子,实现了高效、高色纯度、低效率滚降的器件开发。磷光敏化剂的引入可使三线态激子高效转化为单线态激子。得益于磷光敏化剂较短的激子寿命,基于溶液加工的蓝色多重共振热激活延迟荧光器件不仅实现了13.2%的外量子效率,而且在1000 cd/m^(2)亮度下的效率滚降仅为25.8%。为了进一步抑制Dexter能量转移,我们采用具有外围位阻但发光核相同的分子作为客体,可使外量子效率提升至13.6%,并抑制光谱展宽。该研究为设计高色纯度、高效率的溶液加工器件提供了一个通用的策略。
Although organic light-emitting diodes(OLEDs)have been commercialized and become popular in smartphone,the vacuum deposition process makes them too expensive for mass production and less cost-effective.Herein,we employed highly emissive platinum complex as the sensitizer and multi-resonant thermally activated delayed fluorescence(MR-TADF)molecules as the emitters to demonstrate highly efficient,high color purity,and solution-processed OLEDs with the alleviated efficiency roll-offs.The triplet excitons are rapidly converted to singlet excitons assisted by the phosphorescent sensitizer.Attributed to the reduced triplet exciton lifetime induced by the phosphorescent sensitizer,the MR-TADF OLEDs exhibited a maximum external quantum efficiency(EQE)of 13.2%with a low efficiency roll-off of 25.8%at 1000 cd/m^(2).To reduce Dexter energy transfer between phosphorescence sensitizer and the emitter,an analogue TADF emitter with the peripheral bulky blocking units was employed,which rendered an improved maximum EQE of 13.6%.This investigation presents a general approach to realize high-performance solution-processed electroluminescence.
作者
李家乐
方辉
龚少龙
谢国华
LI Jiale;FANG Hui;GONG Shaolong;XIE Guohua(Sauvage Center for Molecular Sciences,Hubei Key Lab on Organic and Polymeric Optoelectronic Materials,Department of Chemistry,Wuhan University,Wuhan 430072,China;The Institute of Flexible Electronics(Future Technologies),Xiamen University,Xiamen 361005,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2024年第5期699-710,共12页
Chinese Journal of Luminescence
基金
国家自然科学基金(52373195,62175189)
江汉大学光电化学材料与器件教育部重点实验室开放基金项目(JDGD-202301)
国家自然科学基金委员会与瑞典科研与教育国际合作基金会合作交流项目(52211530052)。
关键词
磷光敏化
窄光谱
多重共振
热激活延迟荧光
有机发光二极管
phosphorescent sensitizer
narrow bandwidth,multi-resonance
thermally activated delayed fluorescence
organic light-emitting diodes
