title: Effect of ITO surface modification on the OLED device lifetime.
abstract: 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.
authors.affiliation: Department of Chemistry, National Tsing-Hua University , Hsin-Chu, Taiwan, Republic of China 300.
authors.forename: Szu-Yen
authors.initials: SY
authors.lastname: Yu
authors.forename: Jung-Hung
authors.initials: JH
authors.lastname: Chang
authors.forename: Po-Sheng
authors.initials: PS
authors.lastname: Wang
authors.forename: Chi-I
authors.initials: CI
authors.lastname: Wu
authors.forename: Yu-Tai
authors.initials: YT
authors.lastname: Tao