Effect of Ag nanoparticles on the photoluminescence of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene

Abstract

The key problem which needs to be solved during the commercialization process of the organic light emitting diode (OLED) lighting technology is how to improve the efficiency and stability of optoelectronic materials. In order to solute this issue, we explore the regulation of Ag nanoparticles (NPs) on the photoluminescence (PL) characteristics of an efficient organic optoelectronic polymer poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-vinylene] (MEH-PPV). Because of the coupling between the localized surface plasmons from the Ag NPs and the PL emission of the MEH-PPV, the Ag NPs could effectively enhance the PL intensity, modulate the spectral line shape and shorten the lifetime of interchain species. The temperature-dependent PL measurement exhibits that with the introduction of Ag NPs, the thermal exchange process between the sample and the surrounding environment becomes more effective, and the activation energy decreases from 448 to 318 meV. The excitation intensity (EI)-dependent PL measurement demonstrates that the thermal accumulation effect and the nonlinearity of EI-dependent PL enhancement are both suppressed by the Ag NPs. The results of this study will provide experimental guidance to the design and fabrication of OLED devices with high efficiency and stability.