激子浓度对体异质结型OLED有机磁效应的影响  

Effect of Exciton Concentration on the Organic Magnetic Effect of Bulk Heterojunction Type OLEDs

作　　者：王志奇[1] 王凯 王晓军[1] 陈小伟 白心爱[1] 邱炎儿[1] 张辰锐 薛丽丽[1] WANG Zhi-qi;WANG Kai;WANG Xiao-jun;CHEN Xiao-wei;BAI Xin-ai;QIU Yan-er;ZHANG Chen-rui;XUE Li-li(Department of Physics and Electronic information Engineering,Lvliang University,Lishi,033001,China;Lüliang Power Supply Company,State Grid,Lishi,033000,China;State Key Laboratory of Quantum Optics and Quantum Optics Devices,Shanxi University,Taiyuan 030006,China)

机构地区：[1]吕梁学院物理与电子信息工程系,山西离石033001 [2]国网吕梁供电公司,山西离石033000 [3]量子光学与光量子器件国家重点实验室,山西大学,山西太原030006

出　　处：《量子光学学报》2024年第4期99-107,共9页Journal of Quantum Optics

基　　金：吕梁市高层次科技人才项目(2022RC14);吕梁市高层次科技人才项目(2022RC12);山西省基础研究项目(202103021224318)。

摘　　要：为了研究激子浓度对有机发光器件内部自旋混合过程的影响,本文制备了结构为ITO/Mo O3(5 nm)/NPB (30 nm)/NPB∶Alq_(3)(1:x,70 nm)/Alq_(3)(40 nm)/Cs Cl (0.6 nm)/Al (120 nm)[x=1,2,3,4]的体异质结器件。运用光电磁一体化测量技术,测试了室温下器件的光电性能和有机磁效应。实验发现:常温同一偏压下,随Alq_(3)掺杂浓度增加,器件的MC(Magneto-Conductance,MC)、MEL(Magneto-Electroluminescence,MEL)曲线幅值增大,MC、MEL均增加1.4%;同一掺杂比例的器件,随外加偏压的变大,MC、MEL曲线幅值减小。此外,进一步研究了温度对器件MEL曲线的影响,随温度降低,MEL曲线的线性有所不同,低磁场部分都是快速上升,高磁场部分由缓慢上升变为缓慢下降。利用系间窜越(ISC)、三重态-三重态激子湮灭(TTA)、三重态激子与电荷的猝灭(TCA)等理论对结果进行深入分析。实验结果证明,通过改变掺杂比例,可以实现对器件内部激子浓度的调节,达到改善器件光电性能和有机磁效应的目的。本文深入研究了体异质结器件内部复杂的自旋混合过程,为设计体异质结器件提供了可靠依据。Objective In the research of organic light-emitting devices(OLEDs),the spin mixing process is of great significance as it closely relates to device performance. In order to deeply investigate the effect of exciton concentration on the spin mixingprocess in organic light-emitting devices, the bulk heterojunction devices with the structure of ITO/MoO3(5 nm)/NPB(30 nm)/NPB:Alq_(3)(1:x, 70 nm)/Alq_(3)(40 nm)/CsCl(0.6 nm)/Al(120 nm) [x=1, 2, 3, 4] are fabricated.Methods The optoelectronic properties and organic magnetic effects of the devices are studied at room temperature by utilizingthe photo-electro-magnetic techniques. By applying these techniques, we can accurately obtain and analyze various parametersrelated to the devices' performance, such as current-voltage characteristics, light-emitting intensity under different magneticfields, and the changes in these parameters with respect to different doping concentrations and bias voltages.Results and Discussions We find that both the Magneto-Conductance (MC) and Magneto-Electroluminescence (MEL) curves ofthe devices are enhanced with increasing the doping concentration of Alq_(3) under the same bias voltage at room temperature,among them increase by 1.4%. This indicates a strong correlation between the doping concentration and the performance metricsrelated to spin-dependent transport and light emission. Moreover, the amplitude of MC and MEL curves are reduced with increasingthe bias voltage when the doping ratio remains unchanged. Additionally, the effect of temperature on the MEL curves of thedevices is further investigated. The line-shape of the MEL curves are distinctly modulated with decreasing temperature, involvingthat the MEL curves within low magnetic field ranges increase rapidly, while that within high magnetic field ranges first increaseslowly to decrease.Conclusions These experimental results are deeply analyzed by considering the intersystem crossing (ISC), triplet-triplet annihilation(TTA), and triplet-charge annihilation (TCA) mechanisms. We demonstra

关 键 词：激子浓度 温度 体异质结 有机磁效应 

分 类 号：O433.4[机械工程—光学工程]