title: Au@polymer core-shell nanoparticles for simultaneously enhancing efficiency and ambient stability of organic optoelectronic devices.
abstract: In this paper, we report and discuss our successful synthesis of monodispersed, polystyrene-coated gold core-shell nanoparticles (Au@PS NPs) for use in highly efficient, air-stable, organic light-emitting diodes (OLEDs) and organic photovoltaics (OPVs). These core-shell NPs retain the dual functions of (1) the plasmonic effect of the Au core and (2) the stability and solvent resistance of the cross-linked PS shell. The monodispersed Au@PS NPs were incorporated into a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) film that was located between the ITO substrate and the emitting layer (or active layer) in the devices. The incorporation of the Au@PS NPs provided remarkable improvements in the performances of both OLEDs and OPVs, which benefitted from the plasmonic effect of the Au@PS NPs. The OLED device with the Au@PS NPs achieved an enhancement of the current efficiency that was 42% greater than that of the control device. In addition, the power conversion efficiency was increased from 7.6% to 8.4% in PTB7:PC71BM-based OPVs when the Au@PS NPs were embedded. Direct evidence of the plasmonic effect on optical enhancement of the device was provided by near-field scanning optical microscopy measurements. More importantly, the Au@PS NPs induced a remarkable and simultaneous improvement in the stabilities of the OLED and OPV devices by reducing the acidic and hygroscopic properties of the PEDOT:PSS layer.
authors.affiliation: Department of Chemical and Biomolecular Engineering, ‡KI for the NanoCentury, ⊥Graduate School of Energy, Environment, Water, and Sustainability (EEWS), and #Department of Physics, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 305-701, Korea.
authors.forename: Taesu
authors.initials: T
authors.lastname: Kim
authors.forename: Hyunbum
authors.initials: H
authors.lastname: Kang
authors.forename: Seonju
authors.initials: S
authors.lastname: Jeong
authors.forename: Dong Jin
authors.initials: DJ
authors.lastname: Kang
authors.forename: Changyeon
authors.initials: C
authors.lastname: Lee
authors.forename: Chun-Ho
authors.initials: CH
authors.lastname: Lee
authors.forename: Min-Kyo
authors.initials: MK
authors.lastname: Seo
authors.forename: Jung-Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Bumjoon J
authors.initials: BJ
authors.lastname: Kim
keywords: air stability; core−shell metal NPs; localized surface plasmon resonance; organic light emitting diodes; organic solar cells