银粉含量对印刷型聚合物发光器件的影响(英文)

1)南京邮电大学材料学院,江苏南京 210023; 2)华南理工大学发光材料与器件教育部重点实验室,广东广州 510641

化学物理学; 聚合物发光二极管; 导电银胶; 刮涂工艺; 印刷式电极; 相界面电阻

Effect of Ag content on the performance of cathode-printed PLEDs
Zeng Wenjin1, Zhao Chunyan1, Li Yonghua1, Li Dongmei1, Li Xue1, Zhang Chi2, Peng Junbiao2, Lai Wenyong1, Niu Qiaoli1, and Min Yonggang1

1)School of Materials Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, Jiangsu Province, P.R.China2)State Key Lab of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, Guangdong Province, P.R.China

chemical physics; polymer light-emitting diodes; Ag paste; blade-coating; printed cathode; interface resistance

DOI: 10.3724/SP.J.1249.2016.01018

备注

研究银粉含量和印刷阴极型聚合物发光二极管(polymer light-emitting diode,PLED)之间的构-效关系.实验比较两种不同银粉含量的导电银胶,通过刮涂法制备PLED的阴极.两种银胶的胶体基底相同,区别在于银粉颗粒的含量不同.实验研究银粉的分布状态与器件性能之间的关系.结果表明,银胶中的银粉含量越高,器件的性能越好,主要体现在驱动电压更低、电流密度更大和量子效率更高.偏光显微镜图片显示,提高银胶中银粉的含量,可以优化银粉在印刷阴极/电子传输层之间的分布.通过银粉覆盖率的数据模拟也证明了这一点.为确定银粉覆盖率的提高能够优化器件效率,在器件中通过蒸镀添加薄银层.结果表明,由于薄银层的插入,器件的驱动电压随之下降,器件性能也得到优化.因此,在印刷型的PLED器件中,提高银胶中银粉的含量可以有效减低载流子的注入势垒,达到器件优化的效果.

The structure-activity relationship of the cathode-printed polymer light-emitting diodes(PLEDs)is investigated. Two kinds of Ag pastes on the same paste resin but with different content of Ag particles were applied to prepare the cathodes of PLEDs by the blade-coating. The relationship between the distribution of Ag particles and the performance of PLEDs was investigated. The results indicate that the paste with a higher silver content exhibites better performances, including a lower driving voltage, higher current density and quantum efficiency. In-situ polarized microscopic images reveal that a higher silver content in the paste could lead to a better distribution of Ag at the interface of the cathode and the electron-transporting layer(ETL), which can also be proved by the simulation of the coverage percentage. A thin layer of Ag was inserted by evaporation between the ETL and Ag-paste cathode, which is regarded as equivalent to the increase of Ag coverage at the interface. As expected, the driving voltage of the devices was reduced and the performance improved after the thin layer of thermally-deposited Ag was inserted. Therefore, large Ag contents at the interface benefits the performance of PLED due to the low injection barriers.

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