Enhancement of photoluminescence properties in silver nanoparticles based organic luminophores

Abstract

Metal nanoparticles have been very active research object due to the local surface plasmon resonance effect that can be used in various applications, such as sensors, photovoltaic and Raman spectroscopy. Metallic nanoparticles enhanced fluorescence is an important effect to improve the emission properties of the semiconductor. It offers higher emission efficiency and decreased lifetime via the local electric field enhancement effect of metal nanoparticles induced by its surface plasmon resonance. Initially, inorganic semiconductors were used to show the emission enhancement, but recently more systems consist of organic semiconductors. It is driven by the growing potential of organic materials in the light-emitting diodes, photovoltaics, and solid-state lasers. Synthesis of specific size and shape of nanoparticles is important because it determines the spectrum of surface plasmon resonance which in turn should match the emission spectrum of an organic dye to get the highest enhancement. Silver nanoparticles typically are synthesized in aqueous solution and their transfer to organic solvents is required for application purposes in organic luminophores emission intensity enhancement. We studied prismatic and spherical silver nanoparticles transfer from aqueous to organic media by ultrasonic treatment and shell changing processes. Photoluminescence properties – emission maps, photoluminescence quantum yield and lifetime of obtained nanoparticles solutions mixtures with organic luminophore DWK-1-TB (2-(2-(4-(bis(2-(trityloxy)ethyl)amino)styryl)-6-methyl-4H-pyran-4-ylidene)malononitrile) were studied. Improvements of photoluminescence properties was observed in nanoparticles based organic luminophore solutions. Presence of nanoparticles increased emission intensity, improved photoluminescence quantum yield and shifted excitation wavelength.