Mn-doped ZnO multileg nanostructures were synthesized via in situ thermal oxidation of Zn and MnO2 powder. Spectroscopic measurements show that Mn ions have been doped into the lattice positions of Zn ions, which strongly induce growth of the observed ZnO multileg nanostructure. It is revealed that the growth mechanism of this kind of multileg ZnO:Mn nanostructure is different from the traditional vapor–solid or vapor–liquid–solid nucleation model of ZnO nanostructures. A possible mechanism is discussed on the basis of the growth process of a tetrapod ZnO nanostructure. Furthermore, we report the observation of an additional Raman peak. This peak is considered to have an origin related to Mn dopant in the ZnO nanostructure. This Raman feature can be regarded as an indicator for the incorporation of Mn ions into the lattice positions of the multileg ZnO nanostructure.

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Amorphous ZnO granular films were fabricated by anodizing zinc sheet in 0.5M oxalic acid solution under direct current voltage. The photoluminescence spectrum of the as-anodized sample shows a very broad visible emission band, which can be Gaussian divided into two subbands at 525 and 600nm. Based on their annealing behavior and the growing mechanism of the ZnO films, the two subbands are attributed to optical transitions in oxygen vacancies and oxygen interstitials, respectively. Obvious redshifts of the two subbands were observed with increasing excitation wavelength. Spectral analyses suggest that the excitation wavelength dependences of the two subbands are due to the quantum confinement on the amorphous ZnO nanoparticles mainly with sizes of ∼10nm. This work provides a good understanding of the photoluminescence behavior of amorphous ZnO particles.

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We report optical emission of SiC nanocrystallite films, which clearly shows the quantum confinement effect. Bulk polycrystalline 3C-SiC was first electrochemically etched and then the fabricated porous silicon carbide was ultrasonically treated in water or toluene suspension to disperse into colloidal nanoparticles. Transmission electron microscopy images clearly show that the colloidal nanoparticles have 3C-SiC lattice structure with sizes varying from about 6nm down to below 1nm. The suspension of 3C-SiC nanocrystallites exhibits ultrabright emission with wavelengths ranging from 400to520nm when the excitation wavelength varies from 250to480nm, in accordance with the quantum confinement effect. By adding polystyrene to the toluene suspension containing SiC nanoparticles and coating the mixing solution onto a Si wafer, we obtain the SiC∕polystyrene films that luminesce.

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Aluminum foil was anodized in aged electrolyte under high voltage. The morphology observation shows that the alumina film has a three-layer structure from bottom to top and the middle layer shows large quantities of individual alumina nanotubes. Their formation mechanism is discussed in detail. Under ultraviolet excitation, the alumina film exhibits an emission centered at ϳ400 nm. Based on annealing behavior of the emission band and electron paramagnetic resonance result, the origin of the emission is considered to be due to optical transition in single ionized oxygen vacancy ͑F + center͒ in the alumina. The experimental results can be expected to have favorable applications in optoelectronics and biotechnology.