Near-perfect infrared absorption from dielectric multilayer of plasmonic aluminum-doped zinc oxide

We demonstrated a near-perfect infrared absorber by using nanostructure multilayer of aluminum doped zinc oxide (AZO) and ZnO. The negative real part of permittivity of AZO allows the dielectric multilayer to match the phase of all light reflected. The field amplitudes destructive interference leads to a reflectance closing to zero at ∼1.90 μm. Both experimental and theoretical investigations indicated that the multilayer simultaneously minimized reflectance and transmittance in infrared region, leading to a high absorptance of ∼99% at ∼1.90 μm. These AZO metamaterials will bring more opportunities for simplified fabrications and something new towards plasmonics and artificial optics.