A study on the gas sensing effect on current-voltage characteristics of ZnO nanostructures

Current-voltage characteristics of ZnO nanostructures were studied under different gas ambient using nonequilibrium Green's function and density functional theory, DFT technique. It was found that I-V characteristics of ZnO nanostructures depend strongly on the type of gas molecules present. The sensitivity factor of more than 200% achieved with the presence of a single molecule of NO₂ gas. Meanwhile, there were no significant changes towards CO and NH₃ gas molecules. However, CO adsorption can significantly suppress the transmission spectrum of ZnO nanostructures. Under the same applied bias voltage, the current through ZnO nanostructures decreases with increasing CO concentrations.