Room temperature electrically pumped ultraviolet random lasing from ZnO nanorod arrays on Si

We report the electrically pumped ultraviolet random lasing from ZnO nanorod arrays on Si. Metal-insulator-semiconductor structures in a form of Au/SiO(2)/ZnO-nanorod-array were fabricated on Si. Such devices exhibit random lasing when the Au electrode is applied with a sufficiently high positive voltage. In this context, in the region adjacent to SiO(2)/ZnO-nanorod-array interface, stimulated emission from ZnO occurs due to population inversion and, moreover, light is scattered by the nanorods and SiO(2) films. Therefore, random lasing proceeds due to optical gain achieved by the stimulated emission and multiple scattering.