摘要
本文结合真空热蒸镀与旋涂法,成功制备出金纳米粒(Gold Nanoparticles,Au-NPs)修饰阳极的4种绿光器件.器件结构为ITO/Au-NPs/MoO_(3)/NPB/Alq_(3)/CBP/CsCl/Al.在室温下测量器件的光电特性、磁电致发光(Magneto-Electroluminescence,MEL)和磁电导(Magneto-Conductance,MC).在温度245–95 K,对CBP膜厚为15 nm的器件研究了磁电致发光和磁电导.结果表明,在阳极ITO表面旋涂一层金纳米粒薄膜,器件稳定性得到提升,器件最大亮度为14710 cd/m^(2),最大电流效率为4.79 cd/A.亮度为11890 cd/m^(2),电流效率滚降仅为5.47%,并且在195 K出现与室温完全相反线型的MC曲线.通过机理研究表明,金纳米粒吸附在阳极表面,缺陷被有效钝化,这是提升器件效率稳定的主要原因.利用非洛伦兹方程很好地拟合了245 K,7 V的MC曲线,拟合结果B_(2)=297.37 mT.器件内部的反向系间窜越(RISC)过程引起MC线型反转,由正变为负,三重态激子突破了向单重态激子转换的障碍,提高了三重态激子的利用率.本研究深入探讨了基于Au-NPs低效率滚降器件中的多种微观物理机制,同时也为设计高稳定性器件提供一种思路与可行的研究方法.
In this study,four different kinds of green light-emitting devices with gold nanoparticles modified anode have been successfully fabricated by vacuum thermal evaporation and spin-coating.The device structure is ITO/Au-NPs/MoO_(3)/NPB/Alq_(3)/CBP/CsCl/Al.The photoelectric properties,magneto-electroluminescence(MEL)and magneto-conductance(MC)curves of the devices were measured at room temperature.The MEL and MC curves of the device with the CBP film thickness of 15 nm were measured at ambient temperature ranging from^(2)45 to 9 K.Experimental results show that the stability of the devices improves after spinning a layer of nano-gold film on the surface of ITO.The value for maximum brightness is 14710 cd/m^(2),and current efficiency is 4.79 cd/A.The efficiency roll-off ratio of 5.47%at luminance of 11890 cd/m^(2).In addition,MC curves completely opposite line type appear at 195 K compared with room-temperature.The mechanisms show that main reason for improving the stability of device is that the nanoparticles were adsorbed to the anode surface and defects are effectively passivated.Non-lorentz equation was applied to well fit the MC curve at 245 K under 7 V,and the fitting result B_(2)=297.37 mT.The reverse intersystem crossing(RISC)process inside device reverses the MC line from positive to negative,triplet excitons break through the barriers to conversion to singlet excitons and increase the utilization rate of triplet excitons.We deeply explore the low-efficiency roll-off devices and micro-mechanisms based on Au-NPs,and provide a feasible idea and researchable method for designing high-stability devices in the future.
作者
王成
徐冲
关云霞
李万娇
保希
宋家一
陈丽佳
牛连斌
WANG Cheng;XU Chong;GUAN YunXia;LI WanJiao;BAO Xi;SONG JiaYi;CHEN LiJia;NIU LianBin(College of Physics and Electronic Engineering,Chongqing Normal University,Chongqing 401331,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2022年第9期91-99,共9页
Scientia Sinica Physica,Mechanica & Astronomica
基金
国家自然科学基金(编号:61874016)
重庆市自然科学基金(编号:CSTC2020jcyj-msxmX0282,CSTC2019jcyj-msxmX0148)
重庆市特殊人才支持计划(编号:CSTC 2018kjcxljrc0050)资助项目。
关键词
金纳米粒
缺陷钝化
效率滚降
有机磁效应
自旋混合
gold-nanoparticles
defects passivation
efficiency roll-off
organic magnetic effects
spin mixing
