Recent Progress in Ohmic/Schottky-Contacted ZnO Nanowire Sensors

Figure 3

(a) Transconductance of a ZnO NW FET under different pressures at room temperature, and  mV. Inset: I- curve of the NW under 760, 380, and 10⁻² Torr. (b) Ratio of conductance change versus radius under a vacuum and atmosphere. Inset: a schematic of NW FET channel depletion (depicted by gray shading) caused by adsorption of oxygen molecules. (c) I- curves obtained in 0, 10, 25, and 50 ppm O₂ at  V. Conductance of ZnO NW decreases monotonically with increasing O₂ concentration. Inset: relationship between sensitivity and gate voltage. (d) FE-SEM image of as-grown ZnO NWs, scale bar is 20 μm. Inset image shows a single ZnO NW terminated with a gold nanoparticle, and scale bar is 100 nm [32]. Copyright 2004, AIP Publishing LLC.

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