有机发光二极管中多种微观机制共存的有机磁效应  

The magnetic field effects caused by three-combined mechanisms in organic light emitting diodes

作　　者：卢晨蕾 贾伟尧[1] 白江文[1] 张巧明[1] 令勇洲[1] 刘虹[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》2015年第4期396-402,共7页Scientia Sinica(Technologica)

基　　金：国家自然科学基金(批准号:11374242);中央高校基本科研业务费专项资金(编号:XDJK2014C081)资助项目

摘　　要：为了探究有机发光二极管(OLEDs)中三重态激子参与的多种机制共同作用下磁场效应的变化规律,揭示复杂环境下OLEDs的性能变化规律,本文在具有较高三重态激子能量的磷光材料m CP中掺入单重态与三重态激子能量共振(ES≈2ET)的荧光染料Rubrene,制备了Rubrene掺杂型的OLEDs.实验发现,掺杂器件的电致发光磁场效应(MEL)表现出了复杂变化,且MEL的低场(B≤5 m T)和高场(5 m T≤B≤500 m T)部分随着掺杂浓度的改变都发生了明显的变化.这些MEL曲线可归结为掺杂体系内超精细相互作用、单重态激子裂变和三重态-三重态激子淬灭三种微观过程共同作用的结果;而不直接产生荧光的三重态激子,可以通过一些自旋混合过程,改变单重态激子的比例,从而对器件发光产生重要影响.器件的工作温度和注入电流密度对磁场效应的影响进一步证实了本研究组的观点.The Rubrene-doped organic light emitting diodes were fabricated by doping Rubrene, containing the singlet-triplet energyresonant property （Es≈2ET）, into phosphorescent-based host materials with different concentrations to investigate their magneto-electroluminescence （MEL）. The results show that the MEL responses, including the low field component （B〈5 roT） and the high field component （5 mT 〈B^500 roT）, change significantly with the doping concentration. These MEL curves could be attributed to the hyperfine interaction, singlet excition fission and triplet-triplet annihilation three-combined processes; the triplet excition has important effect on the luminescent intensity in OLEDs through changing the proportion of singlet exciton. In addition, the influence of temperature and injection current density on the MEL further supports our suggestion.

关 键 词：有机发光二极管 有机磁场效应 三重态激子 

分 类 号：TN383.1[电子电信—物理电子学]