Light Absorption and Scattering by Silver/Silver Sulfide Hybrid Nanoparticles

Plasmonic single-crystal silver nanoparticles exhibit high efficiency for the interaction with light and low intrinsic losses across the visible and near-infrared spectral ranges as manifested by weak light absorption and strong light scattering. The addition of a thin surface silver sulfide layer radically increases the light absorption at the expense of decreasing the light scattering. The hybrid silver/silver sulfide nanoparticles retain the high interaction efficiency despite partial damping of the plasmon resonance by the silver sulfide layer. It is postulated that the light energy absorbed by the hybrid nanoparticles is “deposited” in the thin silver sulfide layer, thus opening possibilities for its further utilization. The hybrid nanoparticles of different sizes with varying silver sulfide thickness were characterized by absorption and scattering spectroscopy as well as by X-ray diffraction and atomic force microscopy. The described hybrid nanoparticles present a general strategy for the rational design of structures exhibiting strong light absorption across the visible and near-infrared spectral ranges via the excitation of plasmon resonances.