Using the mixture of zinc oxide and graphite powders as source materials, zinc oxide nanodisks with bulk quantity were fabricated by vapor-phase transport method. The nanodisks have perfect hexagonal shape with about 3μm in diagonal and 300nm in thickness. The growth is favored along six symmetric directions of ±[101¯0], ±[11¯00], and ±[011¯0] with the typical growth along [0001] direction suppressed, which directly leads to the formation of zinc oxide nanodisk. The microstructure and growth mechanism are discussed.

Fluorescence intermittency, or blinking, of individual close-packed clusters containing two or more CdSe-ZnS quantum dots (QDs) was investigated. The QD clusters exhibited rapid, intense blinking that was distinct from that of isolated QDs blinking independently. This enhanced blinking is suggested to occur when the QDs in the cluster become electronically coupled. The nature of this coupling is not known, though electrons trapped from QDs when they blink off may play a role by altering the electronic environment of neighboring QDs and enhancing their fluorescence properties.

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Integrated silicon-on-insulator waveguide-based silicide Schottky-barrier photodetectors were fabricated using low-cost standard Si complementary metal-oxide-semiconductor processing technology. The thin epitaxial NiSi2 layer formed by solid-state Ti-interlayer mediated epitaxy on the top of Si-waveguide absorbs light propagating through the waveguide effectively and exhibits excellent rectifying property on both p-Si and n-Si. NiSi2∕p-Si detectors with tapered geometry demonstrate dark current of ∼3.0nA at room temperature, responsivity of ∼4.6mA∕W at wavelengths ranging from 1520to1620nm, and 3dB bandwidth of ∼2.0GHz. The approaches for further improvement in responsivity are addressed.