Localized surface plasmon resonance of single and dimer platinum nanocubes

This paper presents a numerical investigation of localized surface plasmon resonance in cubic shape platinum nanoparticles using Finite Element Method simulations. The optical response was investigated through systematically varying morphological parameters such as nanoparticle size, surrounding environment, edge-corner rounding, and interparticle spacing in platinum dimers, under X and Y light polarization directions. Increasing the size of platinum nanocubes led to pronounced redshifts and intensity amplification in LSPR spectra, with absorption consistently dominating due to platinum’s high imaginary dielectric component. Gradually rounding the edges and corners induced a blueshift and reduced peak intensity, due to diminished field confinement and minimization of hybrid plasmon modes. The surrounding medium significantly affected LSPR behavior, with higher refractive index environments (silica and alumina) leading to redshifts in peak wavelength while maintaining relatively stable intensity. Dimer configurations under X-axis polarization exhibited strong coupling effects, at low interparticle spacings, including redshifts and spectral broadening, while Y-axis polarization produced minimal changes due to weak transverse interactions. These findings highlight the critical role of geometric precision, dielectric engineering, and polarization control in tailoring the plasmonic properties of transition metal nanostructures for advanced nanophotonic and nanosensing applications.