Efficient Control of THz Transmission of PEDOT:PSS with Resonant Nano-Metamaterials

Nano-metamaterials designed to operate at a certain resonance frequency enhance the magnitude of terahertz (THz) wave transmission by three orders of magnitude or even more. In this pursuit, controlling magnitude of resonant transmission and tuning the resonance frequency is increasingly important for application in low power THz electronics and devices. THz optical properties of chemically doped poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) have been studied, however its effect on the THz transmission properties in combination with nano-metamaterials have not yet been demonstrated. Here we demonstrate the efficient control over resonant THz transmission and tuning of resonance frequency of different nano-metamaterials using PEDOT:PSS, without any toxic chemical doping. By ease of simple solution processing with single step and drop-casting 10 μL aqueous solution of PEDOT:PSS on different nano-metamaterials with varied concentrations, we were able to dynamically control the THz transmission along with resonance frequency. This dynamic control of transmission and shift in resonance frequency can be attributed to improved conductivity of PEDOT:PSS and its interaction with strongly localized THz field of the metamaterial.