FIB fabrication of ZnO nanotetrapod and cross-sensor

This article presents the fabrication of zinc oxide (ZnO) nanotetrapod and cross-nanorods-based sensors. This low-dimensional device is made in a focused ion beam set-up by using nanodeposition for metal electrodes. The gas response of the sensor based on an individual zinc oxide nanotetrapod and on crossed ZnO nanorod for detection of ultraviolet (UV) light and hydrogen at room temperature is presented. It is shown that ZnO tetrapod has potential application as UV and as chemical sensor with multi-terminal construction. The chemisorbed gas molecules on the ZnO surface can extract or donate electrons to ZnO and this effect was used to monitor the electrical resistance values change of the tetrapod sensor. ZnO tetrapod sensor demonstrates sensitivity and selectivity in resistance upon exposure to UV light, H(2), O(2), NH(3), CO, CO(2), and LPG gas. The resistivity change is different for UV and for H(2) gas sensing. The presented ZnO sensor proves to be promising for application in various processes. (c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim