Interaction of Silver Nanoparticles with a Substrate Under Plasmonic Resonance Conditions

Abstract

The interaction between metal nanoparticles and substrates under plasmonic resonance conditions plays a crucial role in various optical applications. In this study, we research the impact of substrate material on the optical response of silver nanoparticles under surface plasmon resonance conditions. Using theoretical modeling based on the quasi-static dipole approximation, we explore how the dielectric constant of the substrate affects the extinction cross-section spectra of silver nanoparticles as a function of nanoparticle size and distance from the substrate surface. The calculation results show significant shifts in the extinction peak and enhancements in the extinction cross-section values when considering different substrate materials, including cellulose, indium tin oxide and silver. It was found that substrates with higher dielectric constants induce larger shifts in the extinction peak towards longer wavelengths and lead to increased extinction cross-section values at the operating wavelength. Furthermore, it was found that the orientation of the external electric field relative to the substrate surface influences the magnitude of these shifts. The results of the study show that while changing the size of the nanoparticles has minimal effect on the position of the extinction peak, increasing nanoparticle size significantly enhances the maximum extinction cross-section values. Additionally, varying the distance between the nanoparticles and the substrate surface causes shifts in the extinction spectra, with larger shifts observed for substrates with higher dielectric constants. These findings provide valuable insights into the design and optimization of plasmonic structures for various optoelectronic applications. By understanding the nanoparticle-substrate interactions and their optical properties, our theoretical study aids in the prediction of optical responses and the development of tailored optical structures for enhanced productivity of their usage. Overall, this study highlights the importance of substrate material selection and nanoparticle-substrate interactions in engineering plasmonic systems for advanced optical applications, paving the way for the design of efficient and optimized optoelectronic devices and sensors.