Hydrogen-Sensing Characteristics of Palladium-Doped Zinc-Oxide NanostructuresPublic Deposited
Semiconductor oxides are important materials in gas-detection systems and can be improved by enhancing the sensitivity and selectivity of oxide sensors to specific gases. This research investigates the effect of palladium dopant (Pd) on the hydrogen gas-sensing ability of ZnO 2-D nanostructures. Photolithography was used to pattern electrodes on various concentrations of Pd-doped ZnO thin films deposited on silicon oxide substrate, and these devices were subsequently used to measure the electrical resistance in response to hydrogen gas flow. Both nanostructure characterization and gas-sensing characterization were conducted on the ZnO thin-film samples. For the nanostructure characterization of the thin films, scanning electron microscopy (SEM) was used to determine the effect of various concentrations of dopant on the grain structure. Energy dispersive spectrometry (EDS) and x-ray photoelectron spectroscopy (XPS) were used to verify the composition of the Pd-doped ZnO thin films, and inductively coupled plasma (ICP) was used to determine the concentration of the doped sol gels. X-ray diffraction (XRD) was used to determine the crystal structure of the doped thin films. For the gas-sensing characterization, the three key assessments used to characterize the sensitivity of ZnO thin films were comparisons between ZnO thin-film sensors and a commercial sensor, comparisons between 2-D ZnO thin-film sensors and 1-D nanolines, and the exposure of the ZnO thin films to UV light.