Semiconductor-Driven Nanostructured Metamaterial with Epsilon-Near-Zero Transition Layer for Tunable Enhanced Absorption

A zero-width layer, where dielectric permittivity experiences a discontinuous jump, is typically used to mimic a metal–dielectric interface. An epsilon-near-zero (ENZ) layer is part of the small transition area that exists in reality. By investigating propagation of surface plasmons at the boundary of semiconductor-based nanostructured metamaterial, we demonstrate that the surface plasmon’s dispersion along with the absorption is altered by a continuous dielectric function. Additional radiative losses result from the surface plasmon’s energy radiating through the ENZ layer. Plasmonic resonance in the presence of a high electric field normal to the metal sheet provides direct proof of the phenomena associated with the transition layer. The transition layer’s electron density is impacted by the electric field, which causes a discernible shift in the plasmonic resonance.