ELECTROLUMINESCENCE FROM RADIATIVE DECAY OF SURFACE-PLASMONS IN ALUMINUM-INSULATOR-INDIUM TIN OXIDE STRUCTURES

Electroluminescence was observed in sandwich structures composed of a thick layer of plasma-deposited hydrogenated carbon and two statistica lly rough aluminum and indium tin oxide (ITO) electrodes. An indicatio n of the presence of surface plasmons in the emission process is prove d by the temperature dependence of the emission-efficiency and of the light spectra. Visible light from surface plasmon decay at the ITO sur face is due to the formation of a metal-enriched layer at the very sur face of the ITO film that occurs during the early phase of hydrogenate d carbon deposition. The light output was dominated by the radiative d ecay of surface plasmons excited at the outer metal-glass interface of a semi-transparent aluminum electrode. Each interface behaved like a probe, sensitive to the low or high energy tail of the electron energy distribution function.