Yu Szu-Yen, Chang Jung-Hung, Wang Po-Sheng, Wu Chi-I, Tao Yu-Tai
Department of Chemistry, National Tsing-Hua University , Hsin-Chu, Taiwan, Republic of China 300.
Langmuir. 2014 Jul 1;30(25):7369-76. doi: 10.1021/la4049659. Epub 2014 Jun 17.
Pretreatment of the indium tin oxide (ITO) surface is generally adopted to improve the charge injection and device performance in the fabrication of organic light-emitting diodes (OLEDs). For the common approaches of surface treatment, such as oxygen plasma treatment, self-assembled monolayer (SAM) adsorption, and the PEDOT:PSS coating, different effects on the device lifetime were observed. A distinctly different driving voltage change with device operation time was obtained and was correlated with the device lifetime. The fast increase in driving voltage for devices based on oxygen-plasma-treated ITO is attributed to the work function change as a result of the change in the composition of the interface with device operation, whereas a rather stable work function for SAM-modified ITO is suggested due to the permanent dipoles associated with the monolayer and the protecting effect of the covalently bound monolayer on the surface composition.
在有机发光二极管（OLED）制造过程中，通常采用对氧化铟锡（ITO）表面进行预处理的方法来改善电荷注入和器件性能。对于常见的表面处理方法，如氧等离子体处理、自组装单分子层（SAM）吸附和聚（3,4-乙撑二氧噻吩）：聚苯乙烯磺酸盐（PEDOT:PSS）涂层，观察到了对器件寿命的不同影响。获得了随器件工作时间明显不同的驱动电压变化，并将其与器件寿命相关联。基于氧等离子体处理的ITO的器件驱动电压快速增加归因于随着器件工作界面组成变化导致的功函数变化，而由于与单分子层相关的永久偶极以及共价键合单分子层对表面组成的保护作用，SAM修饰的ITO的功函数相当稳定。
