Ozone sensing properties of ZnO nanostructures grown by the aqueous chemical growth technique

ZnO nanostructures were deposited on glass substrates by the aqueous chemical growth technique at mild temperatures (95 °C). In general, flowerlike nanostructures are formed, their morphology and dimensions depending on deposition time. Under ultraviolet irradiation and subsequent exposure to ozone atmosphere, the ZnO samples show electrical current changes of three up to six orders of magnitude at room temperature, depending on surface morphology, substrate coverage and average thickness. Samples deposited for 5 h exhibit the highest ozone sensor response, i.e. 106, due to their high surface-to-volume ratio. It is concluded that the ZnO nanostructured samples grown by aqueous chemical growth at low temperatures are promising candidates for semiconductor room temperature ozone sensors.