A ZnO nanowire vacuum pressure sensor

In this study, we report the growth and characterization of lateral ZnO nanowires (NWs) on ZnO:Ga/glass templates. Using x-ray diffraction and micro-Raman spectroscopy, it was found that crystal quality of the as-grown ZnO NWs is good. It was also found that the average length and average diameter of the laterally grown ZnO NWs were 5 μm and 30 nm, respectively. A vacuum pressure sensor was then fabricated using a single NW bridging across two electrodes. By measuring the current-voltage characteristics of the samples at low pressure, we found that the currents were of 17, 34.28, 57.37 and 96.06 nA for the ZnO NW measured at 1 × 10^-3 Torr, 1 × 10 ^-4 Torr, 3 × 10^-5 Torr and 5 × 10^-6 Torr, respectively. These values suggest that the laterally grown ZnO NWs prepared in this study are potentially useful for vacuum pressure sensing.