利用热激子反向系间窜越的特征磁响应探测界面型OLED中的Dexter能量传递过程  

Detection of Dexter energy transfer process in interface-type OLED via utilizing the characteristic magnetoelectroluminescence response of hot exciton reverse intersystem crossing

作　　者：魏福贤 刘俊宏 彭腾 汪波 朱洪强 陈晓莉 熊祖洪 Wei Fu-Xian;Liu Jun-Hong;Peng Teng;Wang Bo;Zhu Hong-Qiang;Chen Xiao-Li;Xiong Zu-Hong(Chongqing Key Laboratory of Micro&Nano Structure Optoelectronics,School of Physical Science and Technology,Southwest University,Chongqing 400715,China;Chongqing Key Laboratory of Optoelectronic Functional Materials,School of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China)

机构地区：[1]西南大学物理科学与技术学院,微纳结构光电子学重庆市重点实验室,重庆400715 [2]重庆师范大学物理与电子工程学院,光电功能材料重庆市重点实验室,重庆401331

出　　处：《物理学报》2023年第18期346-354,共9页Acta Physica Sinica

基　　金：重庆市教委科技项目(批准号:KJQN202200569);国家自然科学基金(批准号:12104076,11874305);重庆自然科学基金(批准号:cstc2019jcyj-msxmX0560);重庆师范大学校级基金(批准号:21XLB050)资助的课题。

摘　　要：基于界面激基复合物作为主体的主-客体型有机发光二极管(organic light emitting diodes,OLEDs)的外量子效率已经突破36%,但其主-客体间能量传递过程还有待深入研究.本文提出一种基于客体Rubrene热激子反向系间窜越(T_(2,Rub)→S_(1,Rub))的特征磁响应探测界面激基复合物型OLEDs中能量传递过程的实验策略.具体通过表征主、客体材料的光物理特性,证明了主-客体单重态激子间的F?rster共振能量传递过程;通过研究界面激基复合物型器件的磁电致发光响应曲线,可视化了主-客体三重态激子间的Dexter能量传递过程,且该过程有效发生对于器件电致发光具有不可忽视的促进作用.本研究不仅为探测OLEDs中Dexter能量传递过程提供切实可行的理论方法,还为进一步设计高性能热激子型OLEDs提供新的实验参考.The maximum external quantum efficiency of the host-guest-type organic light-emitting diodes(OLEDs)with interface exciplex as the host has been over 36%.However,studies about the energy transfer processes occurring from the host to guest remain lacking.Herein,a strategy is proposed to probe the energy transfer processes in interface-type OLEDs by utilizing the characteristic magneto-electroluminescence(MEL)response from the hot exciton reverse intersystem crossing(T_(2,Rub)→S_(1,Rub))of rubrene.Specifically,a donor/spacer/accepter(D/S/A)-type interface exciplex device and a D/spacer:x%Emitter/A(D/S:3%Rubrene/A)-type Rubrene-doped device are fabricated.The Förster resonance energy transfer(FRET)process occurring between the singlet state of the exciplex-host and the singlet state of Rubrene-guest is demonstrated by characterizing the photophysical properties of the donor,accepter,and guest materials.The Dexter energy transfer(DET,T_(1,Host)→T_(2,Rub))process between the triplet state of the host and the triplet state of guest is visualized by the comparative studying of the current-and temperature-dependent MEL response curves of D/S/A and D/S:3%Rubrene/A devices,respectively.More importantly,the occurrence of the DET process greatly promotes the electroluminescence intensity of the D/S:3%Rubrene/A device.Furthermore,we also investigate the differences in the electroluminescence performance of devices at low temperature to demonstrate again the co-existence of FRET and DET process in the D/S:3%Rubrene/A system.Obviously,this work not only provides a promising strategy for probing the DET process in OLEDs,but also paves a new way for designing high-performance“hot exciton”type OLEDs.

关 键 词：界面激基复合物 热激子 Dexter能量传递 磁电致发光 

分 类 号：TB30[一般工业技术—材料科学与工程] TN312.8[电子电信—物理电子学]