Dark plasmon of the rotated silver triangular nanoplate dimer

摘要

Rotated dimers are the common products during the deposition of Ag triangular nanoplates dimers on the glass substrate. In this work, modeling a silver dimer that it rotated around the Z axis shows that the wavelength and intensity of the dark plasmon are flexibly modulated by changing the angle's rotation. Our results show that there are four main plasmonic bands. These resonances are formed due to the plasmon coupling between the dipole mode and quadrupole mode. In addition, the charge density distributions show a high degree of localization near both sides and corners of the nanotriangles. Moreover, It is found that the figure of merit (FOM) has the highest value for θ = 71° due to the lowest value of the full wide at half maximum (FWHM) of the resonance peak. This study may be used to build optical sensors based on metallic nanoparticles with new plasmonic properties.