Transparent conductive oxides for the epsilon-near-zero Tamm plasmon polaritons

Abstract

We demonstrate the possibility of using transparent conducting oxides [aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium tin oxide (ITO)] to form Tamm plasmon polaritons in the near-infrared spectral range where the permittivity of oxides is near zero. The spectral properties of the structures are investigated in the framework of the temporal coupled-mode theory and confirmed by the transfer matrix method. It is found that in the critical coupling conditions, the maximal 𝑄-factor of a Tamm plasmon polariton is achieved when a photonic crystal is conjugated with the AZO film, while at the conjugation with the ITO films, the broadest spectral line is obtained. The sensitivity of the wavelength and spectral width of the Tamm plasmon polariton to changes in the oxide film thickness, bulk concentration of a dopant, and angle of incidence is demonstrated.