title: High-efficiency small-molecule-based organic light emitting devices with solution processes and oxadiazole-based electron transport materials.
abstract: We demonstrate high-efficiency small-molecule-based white phosphorescent organic light emitting diodes (PHOLEDs) by single-active-layer solution-based processes with the current efficiency of 17.3 cdA(-1) and maximum luminous efficiency of 8.86 lmW(-1) at a current density of 1 mA cm(-2). The small-molecule based emitting layers are codoped with blue and orange phosphorescent dyes. We show that the presence of CsF/Al at cathodes not only improves electron transport in oxadiazole-containing electron transport layers (ETLs), but also facilitates electron injection through the reacted oxadiazole moiety to reduce interface resistance, which results in the enhancement of current efficiency. By selecting oxadiazole-based materials as ETLs with proper electron injection layer (EIL)/cathode structures, the brightness and efficiency of white PHOLEDs are significantly improved.
authors.affiliation: Institute of Chemistry, Academia Sinica , Taipei, Taiwan 11529, R. O. C.
authors.forename: Yung-Ting
authors.initials: YT
authors.lastname: Chang
authors.forename: Jan-Kai
authors.initials: JK
authors.lastname: Chang
authors.forename: Yi-Ting
authors.initials: YT
authors.lastname: Lee
authors.forename: Po-Sheng
authors.initials: PS
authors.lastname: Wang
authors.forename: Jhao-Lin
authors.initials: JL
authors.lastname: Wu
authors.forename: Che-Chang
authors.initials: CC
authors.lastname: Hsu
authors.forename: I-Wen
authors.initials: IW
authors.lastname: Wu
authors.forename: Wei-Hsuan
authors.initials: WH
authors.lastname: Tseng
authors.forename: Tun-Wen
authors.initials: TW
authors.lastname: Pi
authors.forename: Chin-Ti
authors.initials: CT
authors.lastname: Chen
authors.forename: Chih-I
authors.initials: CI
authors.lastname: Wu