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.

Recent Advances in the Optimization of Organic Light‐Emitting Diodes with Metal‐Containing Nanomaterials

“…[46] The quality of light generated by OLEDs can be evaluated by the coordinates (CIE x , CIE y ) in 1931 CIE chromaticity diagram, which was established by the International Commission on Illumination in 1931. [47] The center point with coordinates of (0.333, 0.333) in the diagram is defined as the standard white light as shown in Figure 3. The closer to the center point, the better the color saturation of white light is.…”

Enhancement and Reduction of Nonradiative Decay Process in Organic Light-Emitting Diodes by Gold Nanoparticles

“…It is well known that the SPRE was induced by the interaction between the surface charge of the metal and the electromagnetic field of the incident light [10][11][12][13][14][15][16]. In addition, when the metal nanoparticles are close to the fluorescent molecule, the luminous efficiency of the fluorescent molecules can be greatly increased by a decrease in the decay time of the excitons for the devices [17].…”

Effects of Gold-Nanoparticle Surface and Vertical Coverage by Conducting Polymer between Indium Tin Oxide and the Hole Transport Layer on Organic Light-Emitting Diodes

“…As the Au-NP size increased, a red-shift was induced in the UV spectra. [4][5][6][7][8]14,15 In Figure S6(b), the EL intensities of the examined devices were slightly enhanced at approximately 570 nm as the Au-NP size increased. The EL intensities at approximately 570 nm of the devices with small To understand the different current density and luminance behaviors exhibited by the examined devices, extinction crosssectional spectral models were simulated using the finitedifference time-domain (FDTD) method for each of the different device structures.…”