Department of Chemistry, Renmin University of China, Beijing, People's Republic of China.
Nanotechnology. 2010 Nov 26;21(47):475502. doi: 10.1088/0957-4484/21/47/475502. Epub 2010 Oct 29.
We report a practical vacuum pressure sensor based on a ZnO nanowire array (NWA). An oriented single-crystal ZnO NWA was synthesized by electrodeposition. The device consists of two ITO glass plates coated with a ZnO NWA. Scanning electron microscopy (SEM) and the x-ray diffraction (XRD) pattern show that the as-grown ZnO NWAs are single-crystal and roughly oriented with the ZnO(002) plane parallel to the substrate. Through measuring the pressure dependent resistance of the sensor at different gas species and temperatures, we discovered that the resistance increases monotonically with vacuum pressure. This demonstrates that a practical vacuum sensor could be fabricated since measurements were carried out with a normal multimeter, with no need for the high sensitivity and costly equipment as routinely required in nanotechnology for extremely weak signals. Measurement at elevated temperature (300 °C) showed that the vacuum sensor is much stabler and more sensitive to O(2) pressure. The principle of the device relates to the adsorbed oxygen species on the large surface area of a ZnO NWA to form a resistive depletion layer at the nanowire (NW) surface.
我们报告了一种基于氧化锌纳米线阵列（NWA）的实用真空压力传感器。通过电沉积合成了取向单晶 ZnO NWA。该器件由两块涂有 ZnO NWA 的 ITO 玻璃板组成。扫描电子显微镜（SEM）和 X 射线衍射（XRD）图谱表明，所生长的 ZnO NWAs 是单晶的，大致取向，其 ZnO（002）面与衬底平行。通过测量不同气体种类和温度下传感器的压力相关电阻，我们发现电阻随真空压力单调增加。这表明可以制造出实用的真空传感器，因为测量是使用普通万用表进行的，而不需要像纳米技术中通常需要的那样，使用高灵敏度和昂贵的设备来测量极其微弱的信号。在高温（300°C）下的测量表明，真空传感器更加稳定，对 O2 压力更敏感。该器件的原理与 ZnO NWA 大表面积上吸附的氧物种有关，在 NW 表面形成电阻耗尽层。
