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Ag-BaO thin films have been fabricated by evaporating silver into BaO semiconductor thin film in ultrahigh vacuum and the quantum yield distribution in the visible region between 1.5 and 3.7 eV has been measured. The quantum yield spectra have a peak when the energy of the incident light is 2.5 eV. The direct transitions and surface plasmon resonance of silver nanoparticles appear to be very important in determining the shape of quantum yield spectra. The explanation for the small discrepancy between the experimental result and the theoretical data is given.

The ultraviolet light emitting diode based on n-ZnO-nanowire/p-Si heterojunction was fabricated. Quasi-arrays of ZnO nanowires were grown on p-Si substrates using a simple low-temperature hydrothermal method that would be easily extended to mass production. As-grown ZnO nanowires showed good crystallinity, a preferable c axial orientation, and strong ultraviolet emission under optical excitation. Different kinds of cathodes were made to form the electrical contact. The I-V characteristics were diode-like. Under forward bias, the heterojunction diode emitted strong ultraviolet light at 387nm and weaker green light.