Optoelectronic Transitions in Gold Spherical Nanoparticles - A Simulation Study

This study examined extinction spectra, electric field intensity, and their variations due to various semiconductor medium, for gold nanoparticles, using Nanosphere Optics Lab Field Simulator which is based on Mie’s theory of scattering by sphere. The peak extinction wavelength and bandwidth are found to get varied with size of the gold nanoparticle, in four different regimes. Asymmetric distributions of electric fields are observed in particles typically larger than 25nm. The significant differences are found in the results due to changes in the embedding medium. The gold nanoparticles' unique tunable electro-optical properties may therefore be useful for medical, health care, industrial catalysts, and other consumer products. The study shows improved results may be obtained in the medium size range i.e. 25-75nm. In addition, the selectivity can be improved linearly as the refractive index of the host material increases.