Study of Plasmonic Properties of Size and Shape-Tunable Copper Monosulphide Particles in the NIR Range

This work is devoted to the theoretical study of the extinction spectra of plasmon copper monosulfide particles. The study was conducted for spherical and ellipsoidal particles with variable size. It was found that the deviation from the particles sphericity lead to shift in the position of the extinction peak on the spectral scale and change in the shape of the spectral curve. An increase in the ratio of the ellipsoid semi-axes lengths leads to the red-shift and a significant increase in the extinction peak amplitude. Besides, the position of the plasmon peak, in addition to the geometric parameters, is influenced by the dielectric properties of the media. It was found that an increase in the media refractive index leads to a significant red-shift of the plasmon peak, an increase in width and a decrease in its amplitude. Thus, ellipsoidal copper monosulfide particles exhibit improved plasmon characteristics and have the prospect of being used in the NIR.