Enhanced current efficiency of organic light-emitting devices due to a broad localized surface plasmonic resonance of Au–ZnO nanocomposites

Abstract

Organic light-emitting devices (OLEDs) were fabricated with Au–ZnO nanocomposites (NCs) synthesized by using a sol–gel process in order to enhance their current efficiency. Photoluminescence (PL) and time-resolved PL spectra showed an enhanced fluorescence emission due to the localized surface plasmonic resonance (LSPR) of the Au–ZnO NCs. The electroluminescence intensity of the OLEDs with Au–ZnO NCs at a wavelength of 523nm was significantly increased by a factor of 0.84 in comparison with that of the OLEDs with ZnO nanoparticles (NPs). The current efficiency of the OLEDs with Au–ZnO NCs at 50mA/cm2 was 0.46cd/A higher than that of the OLEDs with ZnO NPs. The enhanced current efficiency in the OLEDs with Au–ZnO NCs was dominantly attributed to the existence of the LSPR due to the presence of the Au NPs in the ZnO layer.