High selectivity color filters based on bismuth enhanced plasmonic nanorods

In view of the low intensity of surface plasmon resonance in nanorod-array based color filters, we propose a Bi-SiO2-Ag nanorod array color filter, which takes advantage of the perfect absorption of the incident light by bismuth and the enhancement effect of metal–insulator–metal (MIM) cavity on localized surface plasmon resonance. By changing the thickness of silicon dioxide in the middle layer to adjust the resonance wavelength and using the COMSOL Multiphysics software to study and verify, we show that the proposed device can achieve filtering effect in the visible and near-infrared spectrum range, leading to up to 95% reflectivity in a specific wavelength range. In addition, the full width at half maximum (FWHM) of the device is considerably lower than that of traditional metallic materials, significantly reducing color crosstalk. Therefore, it can be used as a reflective color filter. The proposed structure has many potential applications in the fields of photoelectric detection, image sensing and display.