We use low energy electron diffraction, Auger electron spectroscopy, and ultraviolet and x-ray photoemission spectroscopy to study the surface structure, stoichiometry, and electronic properties of n-and p-type GaN ͑0001͒ grown by metal-organic chemical vapor deposition. Ordered (1 ϫ1) surfaces with nearly stoichiometric composition are prepared by nitrogen sputtering and annealing. The band bending is found to be 0.75Ϯ0.1 eV up and 0.75Ϯ0.1 eV down for n-and p-type samples, respectively. The work function, electron affinity, and Ga 3d core level binding energy are also determined.

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The luminescent properties of ZnO nanocrystals doped with divalent manganese and europium ions show efficient broad-band emission at room temperature. These ZnO based quantum confined atoms potentially offer efficient nanophosphors that can be excited in the near UV range for applications in the solid state lighting, displays and optically pumped lasers.