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Individual β-Ga2O3 nanowires as solar-blind photodetectors are investigated. The detectors show encouraging advantages to 254 nm light. The dark current is on the order of pA. The conductance of the nanowire increases by about three orders of magnitude under 254 nm ultraviolet illumination. The upper limits of the response and recovery time are 0.22 and 0.09 s, respectively. These results indicate that β-Ga2O3 nanowires have potential applications in realizing future miniaturized solar-blind photodetectors. [ABSTRACT FROM AUTHOR]

Positive temperature coefficient of resistance is observed on single Cd-doped ZnO nanowires. The current along the nanowire increases linearly with the bias and saturates at large biases. The conductance is greatly enhanced either by ultraviolet illumination or infrared illumination. However, the conductance decreases with increasing temperature, in contrast to the reported temperature behavior either for ZnO nanostructures or for CdO nanoneedles. The increase of the conductance under illumination is related to surface effect and the decrease with increasing temperature to bulk effect. These results show that Cd doping does not change surface effect but affects bulk effect. Such a bulk effect could be used to realize on-chip temperature-independent varistors. [ABSTRACT FROM AUTHOR]

We present experimental evidence of in situ growth of carbon nanowires on the tip of a carbon nanotube under an applied voltage of 150 V. The grown nanowires with the well-defined geometry and diameter less than ten nanometers are structurally amorphous in nature and result in the solid carbon nanotube-nanowire junction with minimum junction size. The as-generated carbon nanotube-nanowire junction with a distinctive morphology clearly shows evidence of the bonding between the carbon atoms at the tip of carbon tube. The carbon nanotube could be used as a template for in situ growth of the carbonate nanowires under a strong electric field. The measured current-voltage (I-V) characteristic of the nanotube-nanowire contact shows a nonlinear relation between the current and applied bias voltage due to the saturated sp3 bonds formed at the junction. The detected I-V behavior suggests the formation of the metal/insulator/metal structure at the nanotube-nanowire junction. [ABSTRACT FROM AUTHOR]

Individual ZnO nanowire transistors are fabricated, and their sensing properties are investigated. The transistors show a carrier density of 2300 μm-1 and mobility up to 6.4 cm2/V s, which are obtained from the ISD-VG curves. The threshold voltage shifts in the positive direction and the source-drain current decreases as ambient oxygen concentration increases. However, the opposite occurs when the transistors are under illumination. Surface adsorbates on the ZnO nanowires affect both the mobility and the carrier density. Our data are helpful in understanding the sensing mechanism of the gas sensors. [ABSTRACT FROM AUTHOR]