Carbothermal Reduction Chemical Vapour Deposition Growth of Amorphous ZnO Nanostructures Towards Humidity Sensing

ZnO nanostructured thin films were grown using carbothermal reduction CVD growth with ZnO to C ratio of 1:1. The influence of the oxygen gas flow to the morphologies and electrical properties of ZnO nanostructured thin films was investigated. The XRD results demonstrate that sample deposited with the presence of oxygen gas deteriorate the crystalline quality of the film and caused poor electrical conductivity. Sample deposited without oxygen gas had larger grain sizes by 6-fold and conductive with resistance of 3.3 kO. Subsequently, the conductive nanostructured ZnO thin film was tested for humidity sensing and showed an excellent sensitivity towards humidity of 5.2 kO/RH when RH was varied from 65% to 95%