Investigation of electrically-induced light emission in epsilon near zero (ENZ) heterostructure.

Electrically driven plasmonic nanostructures can generate and guide highly confined light. Light emission and the excitation of surface plasmon polaritons by inelastic electron tunneling have been shown in metal-insulator-metal heterostructures. Similar to metals, thin films of conducting oxides whose real part of permittivity (“epsilon”) goes to zero, or epsilon-near-zero (ENZ) materials, support plasmon polariton modes. In this work I study the inelastic electron tunneling and possible ENZ mode excitation and light emission from ENZ heterostructures. Indium doped tin oxide (ITO) and HfO2 has been used as the ENZ material and insulator, respectively. When the hot electrons injected by the means of electrical biasing across the junction of the heterostructure, they will emit the extra energy in terms of photons. The photons excite the ENZ mode in the ITO and can potentially be emitted and enhanced by the surface scattering or output coupling from nanoantenna.