Cost-effective nebulizer sprayed ZnO thin films for enhanced ammonia gas sensing - Effect of deposition temperature

ZnO thin films were deposited onto glass substrates using a simple and low-cost homemade nebulizer spray technique by keeping the substrate temperature at 350, 400 and 450 °C. Their ammonia gas sensing property at room temperature under darkness was studied. The results show that the ZnO films deposited at 400 °C substrate temperature exhibit the best response time as well as shortest recovery time. The large number of oxygen vacancies presents in this film and the suitable surface morphology with increased surface to volume ratio may be the reasons for the enhanced gas sensing property of this sample. The photoluminescence, FESEM and XRD results are correlated appropriately with the gas sensing properties of the samples.