Searching for high similarity of longitudinal local surface plasmon resonance in gold and silver nanobipyramids

Metal nanobipyramids is a new type of nanoparticle, that has been widely studied due to their remarkable LSPR properties. In this paper, gold and silver nanobipyramids were simulated by the finite difference time domain (FDTD) method. The results show that the longitudinal optical properties and electric field enhancement of gold and silver nanobipyramids are almost the same under a specific aspect ratio. The above results are verified by the core-shell structure. The research results of the two extreme states of absolute sharpness and non-sharpness of nanobipyramids show that the gold and silver nanobipyramids with different sharpness can achieve high similarity of longitudinal local surface plasmon resonance by changing their aspect ratio. The possible reasons for the high similarity of the electric field enhancement effect and extinction phenomenon of gold and silver nanobipyramids under a specific aspect ratio are analyzed by the plasmon resonance mechanism and Gans theory. These results have a great reference significance for the study of gold and silver nanoparticles, including their related properties and applications.