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Effect of polydispersity, bimodality, and aspect ratio on the phase behavior of colloidal platelet suspensions J. Chem. Phys. 137, 134906 (2012) Autonomous colloidal crystallization in a galvanic microreactor J. Appl. Phys. 112, 074905 (2012) Colloidal cluster crystallization dynamics J. Chem. Phys. 137, 134901 (2012) Position-displacement correlations in QELSS spectra of non-dilute colloids J. Chem. Phys. 137, 124901 (2012) Photoluminescence dynamics in solid formulations of colloidal PbSe quantum dots: Three-dimensional versus two-dimensional films ZnS nanoparticles were prepared by chemical precipitation of Zn 2ϩ with sulfur ions in aqueous solution. The ultraviolet-excited samples reveal detailed structure in the luminescence spectra. A doublet pattern observed in the long wavelength region is attributed to the coexistence of the two crystalline forms in ZnS particles. The visible luminescent radiation at 590.1 nm is due to Mn impurities. The dominant emission band at short wavelengths exhibits a quadruple fine structure with peaks located at 416.1, 423.9, 430.1, and 437.8 nm which are identified with optical transitions arising from vacancy and interstitial sites for both Zn and S atoms.

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Silicon vapor from a magnetron sputter source was deposited onto highly oriented pyrolytic graphite, resulting in the formation of nanoscale wires. The structures were analyzed by scanning tunneling microscopy. The wires are from 3 to 7 nm in diameter and at least 100 nm long. They tend to be assembled parallel in bundles. In order to understand the observed quasi-one-dimensional structures, diamondlike and fullerenelike wire models are constructed. Molecular-orbit calculations yield binding energies and band gaps of such structures, and lead us to propose a fullerene-type Si 24 -based atomic configuration for nanowires of silicon.

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