Silver Ellipsoidal Nanoparticles for Surface Enhanced Raman Scattering Applications

The plasmon absorption cross-section spectra for spherical nanoparticles of silver, gold, and copper were calculated and studied. Silver nanoparticles are characterized by the highest intensity of absorption peak. The absorption spectra of ellipsoidal silver nanoparticles are considered in detail. Such nanoparticles demonstrate significant enhancement of the electric field at the ends of the ellipsoid and can be tuned by changing the shape. Change in the shape of nanoparticles from spherical to ellipsoidal in two different axes results in splitting the absorption spectrum of the silver nanoparticles into two separate peaks. It was shown that silver ellipsoidal nanoparticles are promising candidates for surface-enhanced Raman spectroscopy that can work at two different excitation wavelengths of 532 nm and 785 nm, correspondingly.