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Single crystal ZnO nanowires are synthesized and configured as field-effect transistors. Photoluminescence and photoconductivity measurements show defect-related deep electronic states giving rise to green-red emission and absorption. Photocurrent temporal response shows that current decay time is significantly prolonged in vacuum due to a slower oxygen chemisorption process. The photoconductivity of ZnO nanowires is strongly polarization dependent. Collectively, these results demonstrate that ZnO nanowire is a remarkable optoelectronic material for nanoscale device applications. [ABSTRACT FROM AUTHOR]

Examines the imaging of silver nanoparticles on graphite basal plane surfaces. Use of electrostatic force microscopy; Determination of the lateral resolution of the images; Accumulation of a positive charge on the silver particles.

Examines the deposition of metal nanostructures onto silicon (111) surfaces by field evaporation. Induction of metal field emission by the application of tip-negative bias pulses; Use of scanning tunneling microscope; Confirmation of the metallic composition of the structures.

Reports that pulse-induced nanometer-scale lithography has been performed on graphite surfaces that were in contact with pure water or other organic liquids. Observation of reproducible control over the pit diameter in aqueous solutions.

Procedures are described for insulating metal scanning tunneling microscope (STM) tips with either glass or polymer coatings. In solutions containing 0.10 M of a reversible redox couple, Fe(CN)-3/-46 , the faradaic limiting current to polymer coated tips was 200–500 pA and that for glass coated tips was <10 pA. For polymer insulated tips, steady-state currents of 10–100 pA were observed at tip-sample displacements less than 0.3 μm. The suppression of faradaic current achieved by these coating procedures enabled the collection of the first atomic resolution STM images of highly ordered pyrolytic graphite electrodes in contact with redox-active electrolytes. Preliminary data for the in situ electrochemical characterization of these tips are also discussed. [ABSTRACT FROM AUTHOR]

Investigates the time evolution of the topography of an oxidized silicon (Si) surface immersed in an aqueous 40% NH[sub 4]F etching solution. Use of scanning tunneling microscopy; Production of Si pillars at shielded surface locations; Suppression of gas evolution and roughening by reductant addition.