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Full-Text Articles in Physics
Frequency Multiplication In Nanowires, Marius Ghita, Ed Godshalk, Gary Goncher, Raj Solanki
Frequency Multiplication In Nanowires, Marius Ghita, Ed Godshalk, Gary Goncher, Raj Solanki
Physics Faculty Publications and Presentations
Frequency multiplication in silicon and ZnO nanowire based Schottky and p-n diodes has been demonstrated at fundamental frequencies of 70 MHz and 500 MHz. Our motivation for using nanowires contacted at their tips was to minimize the spreading resistance and boundary capacitance in order to produce higher cut-off frequencies and conversion efficiencies compared to planar diodes. The data presented here are limited to the lower GHz range by the frequency response of the experimental apparatus. However, by employing microwave waveguides and higher fundamental source frequencies, it should be possible to reach much higher output frequencies with nanowire-based diodes.
Synthesis And Characterization Of N- And P- Doped Tin Oxide Nanowires, Hoang Tran, Shankar B. Rananavare
Synthesis And Characterization Of N- And P- Doped Tin Oxide Nanowires, Hoang Tran, Shankar B. Rananavare
Chemistry Faculty Publications and Presentations
Bulk-scale synthetic methods for preparing doped tin oxide (SnO2) nanowires (NWs) are presented. n-and p-doping is achieved through insertion of Antimony and Lithium in tin oxide lattice, respectively. We also present a comparison of the structural and optical properties of SnO2 nanoparticles (NPs), and SnO2 NWs. Both n-type and p- type NWs display a characteristic red shift in their photoluminescence (PL) spectra. Surface plasmons observed in these systems imply high carrier concentrations. These corrosion resistant materials are useful in fabricating ultra-sensitive gas detectors and transparent electronics.
Bis Photobase Generator, Hoang Tran, Shankar B. Rananavare
Bis Photobase Generator, Hoang Tran, Shankar B. Rananavare
Chemistry Faculty Publications and Presentations
The extension of 193nm technology is desirable due to the magnitude of past investments. Since “optical” advancements are increasingly difficult, there is a strong demand for more sophisticated “smart” resists to increase pattern density. Many studies have proven double pattering can be used for the extension of 193nm lithography. In this study, a new class of two stage photo base generators will be introduced along with the synthetic procedure and molecular characterization. The characterizations for exposure study by NMR have shown typical characteristics to stage decomposition under the exposure of 254nm light as well as promising pitch division. GCMS was …
Selective Growth Of Single-Crystalline Zno Nanowires On Doped Silicon, Rolf Könenkamp, Robert Campbell Word, M. Dosmailov, J. Meiss, Athavan Nadarajah
Selective Growth Of Single-Crystalline Zno Nanowires On Doped Silicon, Rolf Könenkamp, Robert Campbell Word, M. Dosmailov, J. Meiss, Athavan Nadarajah
Physics Faculty Publications and Presentations
We report the growth of single-crystalline ZnO nanowires on n- and p-type Si wafers by electrodeposition. On strongly doped n-type Si high-quality nanowires can be grown under similar conditions as used for metallic substrates. For low electron concentrations occurring in weakly n-type or in p-type wafers, nanowire growth is inhibited. This difference allows selective growth in strongly n-type areas. The inhibited growth on weakly n-type and p-type wafers can be improved by applying stronger cathodic electrode potentials or by illuminating the growth area. The wires on n-Si show efficient electroluminescence covering the visible and extending into the ultraviolet spectral range.
Vertical Nanowire Light-Emitting Diode, Rolf Könenkamp, Robert Campbell Word, C. Schlegel
Vertical Nanowire Light-Emitting Diode, Rolf Könenkamp, Robert Campbell Word, C. Schlegel
Physics Faculty Publications and Presentations
We report room-temperature, white-color electroluminescence in vertically oriented ZnO nanowires. Excitonic luminescence around 380 nm is observed as a shoulder on a broader defect-related band covering all of the visible range and centered at 620 nm. The ZnO nanowires are grown in a low-temperature process on SnO2-coated glass substrates, employing a technique that is suitable for large-area applications. The nanowires are robustly encapsulated in a thin polystyrene film deposited from high-molecular-weight solutions. Electron injection occurs through the transparent SnO2 layer, while hole injection is mediated by a p-doped polymer and an evaporated Au contact. Stable device operation …
Vertical Nanowire Transistors With Low Leakage Current, Jie Chen, M. C. Lux-Steiner, Rolf Kӧnenkamp, S. Klaumünzer
Vertical Nanowire Transistors With Low Leakage Current, Jie Chen, M. C. Lux-Steiner, Rolf Kӧnenkamp, S. Klaumünzer
Physics Faculty Publications and Presentations
A vertical field-effect transistor based on semiconductor nanowires is reported. The fabrication of the device uses a self-supporting flexible nanostructured polymer foil as a template and an electrochemical growth technique for the preparation of the semiconductor. The fabrication process is substantially simpler, and the mechanical robustness is strongly increased as compared to the original device. The channel region of the transistor has a diameter of ∼100 nm and a length of ∼50 nm. Operation in the hole depletion mode allows a change of the transfer conductance by ∼50% when the gate voltages is changed in the range ∓1 V. The …
Vertical Nanowire Transistor In Flexible Polymer Foil, Jie Chen, Rolf Könenkamp
Vertical Nanowire Transistor In Flexible Polymer Foil, Jie Chen, Rolf Könenkamp
Physics Faculty Publications and Presentations
Fabrication and operation of a vertical nanowire field-effect transistor is reported. The device is prepared by growing vertical wires in the cylindrical pores of a polymer foil stack. The nanowirediameter is approximately 100 nm, the packing density up to 10⁸ cm⁻². The polymer foil stack consists of two polymer layers and an intermediate metal layer. Cylindrical holes are prepared in this stack by using fast ion irradiation and subsequent etching. Well-defined cylindrical openings with diameters between 50 and 150 nm are obtained. The semiconductor growth involves electrodeposition of the p-type quaternary compound CuSCN. Electrical measurements on first devices show transistor …