Effect of hydrogen-related shallow donor on the physical and chemical properties of Ag-doped ZnO nanostructures

Abstract

Silver-doped zinc oxide nanostructures (Ag/ZnO NSs) with Ag content of 0 wt%, 5 wt%, 10 wt%, and 20 wt% were synthesized using a hydrothermal technique. The prepared nanostructures were annealed at 500 °C for 2 h. The samples were characterized by using scanning electron microscopy, FTIR, X-ray diffraction (XRD), and electrical conductivity. FTIR spectra confirms the presence of hydrogen-related shallow donor defects in the Ag/ZnO NSs, which bind to the oxygen vacancy ({text{H}}_{text{O}}) and consequently plays a significant role in the physicochemical properties of the metal oxide nanostructures. The {text{H}}_{text{O}} defects are blended to O- and Zn-polar Ag-doped ZnO NSs, depending on their polarity. XRD results verified that Ag/ZnO NSs have a polycrystalline hexagonal structure. Williamson–Hall methods were used to estimate the microstructural properties of polycrystalline nanostructures. The electrical conductivity increased from 0.60 to 1.10 µS/cm, and the bandgap energy decreased from 3.36 to 3.10 eV by increasing the Ag from 0 wt% up to 20 wt%.