Enhanced frequency and amplitude modulation of THz metasurfaces based on CdSe/CdS quantum rods

The integration of the solution-processed nanomaterial spin-coated on metasurfaces offers a potential method to dynamically control the electromagnetic response of the metasurfaces via the interaction between the surface plasmon polariton (SPP) resonance of nanocrystal and the metasurfaces, which has the low-cost and large-scale advantages in the industrial production. In this work, the high temperature synthesized CdSe/CdS quantum rods (QRs) are incorporated into the metasurfaces with the coupled split-ring resonators to modulate the resonance frequency and transmittance amplitude. The experiment results demonstrate that the frequency shift is effectively controlled by different speeds of spin-coating, and the transmittance reduction is observed with the pump power increasing on account of the heterojunction formation in the QRs-metasurfaces-silicon hybrid structure. The numerical simulations and electric field distributions illustrate the dynamic physical process of the modulations. These results indicate that the QRs solution is a good candidate material in the active modulation of terahertz metasurfaces. © 2020 Elsevier B.V.