Optical properties of gold nano-triangular prisms

Abstract

Compared with bulk materials, the corresponding metal nanoparticles have different optical and nonlinear optical effects. The research and analysis show that the properties of nanostructures with different sizes or shapes are different when the materials are the same. For Au nanoparticles, their SPR absorption bands can be tuned throughout the visible spectrum by changing the size and shape of nanoparticles. In this paper, the optical properties of gold nontriangular structures have been studied by finite difference time domain (FDTD) method. The effects of size, thickness and dielectric constant of gold nanometer triangle on its absorption spectrum were discussed. There are three absorption peaks in the cash nontriangular structure. When the thickness is the same (20nm), with the increase of the size of the gold triangular prism structure, the three absorption peaks shift red, the red shift speed increases gradually, and the absorption coefficient increases in turn. The red shift velocity of the main peak absorption peak is stronger than that of the secondary absorption peak. Under the same size structure (100nm), with the increase of gold nanometer triangle thickness, the main absorption peak shifts blue and the absorption coefficient decreases in turn. When the size and thickness are the same, with the increase of dielectric constant, the three absorption peaks shift red, and the absorption coefficient decreases in turn.