Terahertz electroluminescence of surface plasmons from nanostructured InN layers

The terahertz (THz) emission with the maximum at the 3–5 THz is observed under electrical pumping from InN epilayers, where structural imperfections such as nanocolumns, pores, and In clusters are situated with a certain periodicity. This radiation is ascribed to the spontaneous emission of surface plasmon polariton like waves guided in thin surface/interior layers and coupled to electromagnetic field at these imperfections. These waves are generated thermally under applied electric field. The registered THz spectra and power dependences are well consistent with this plasmon-related radiation mechanism.