反向系间窜越和三重态激子湮灭共存体系的有机发光磁效应  

The magneto-electroluminescence with the coexistence of reverse intersystem crossing and triplet-triplet annihilation in organic light emitting diodes

作　　者：邹越[1] 贾伟尧[1] 陈秋松[1] 袁德[1] 陈历相[1] 向杰[1] 陈颖冰[1] 张巧明[1] 熊祖洪[1] 

机构地区：[1]西南大学物理科学与技术学院,重庆400715

出　　处：《中国科学：技术科学》2016年第2期184-190,共7页Scientia Sinica(Technologica)

基　　金：重庆市科委自然科学基金(编号:CSTC;2010BA6002);国家自然科学基金(批准号:11374242;11404266)资助项目

摘　　要：利用具有反向系间窜越（RISC）特性的荧光材料4-（Dicyanomethylene）-2-tert-butyl-6-（1,1,7,7-tetramethyljulolidin-4-yl-vinyl）-4H-pyran（DCJTB）制备了掺杂型有机发光器件,并在20~300 K温度范围内测量了器件的磁致发光曲线（即magneto-electroluminescence,MEL）.实验发现,这些MEL曲线表现出奇特的线型：先在低场部分（〈10 m T）小幅度地快速下降,再随着磁场的增加大幅度地缓慢下降,最终低场和高场都表现为负的MEL,这与具有系间窜越的激子型器件的MEL明显不同.另外,MEL曲线在低场和高场的下降幅度都受注入电流和工作温度的调控.通过分析三重态激子参与的自旋相关过程,认为这些负的MEL是由RISC与三重态激子湮灭（TTA）过程共同引起的,并且三重态激子的寿命是影响RISC过程的主要因素.By utilizing reverse intersystem crossing（RISC） property of fluorescen tmaterial 4-（Dicyanomethylene）-2- tert-butyl-6-（1,1,7,7-tetra methyljulolidin-4-yl-vinyl）-4H-pyran（DCJTB）, the doped organic light emitting diode was fabricated. The Magneto-electroluminescence（MEL）were measured under different temperatures（20–300 K）. The MEL curves show a sharp decrease in low field（〈10 m T）, followed by a slow fall in high field with increasing magnetic field, i.e. the values of the MEL are negative. The novel line shape is greatly different from the exciton-type device with intersystem crossing property. In addition, the decline of the MEL in low field and high field is modulated by current and temperature. Through the analysis of the spin related process among triplet excitons, we suggest that the MEL curves of DCJTB-doped device are caused by RISC process and triplet-triplet annihilation process. Moreover, the lifetime of triplet exciton is the main factor which influences RISC process.

关 键 词：有机发光磁效应 反向系间窜越 三重态激子湮灭 

分 类 号：TN383.1[电子电信—物理电子学]