Probing the impact of Ba on properties of ZnO at the nanoscale: optical, dielectric and antibacterial activity evolution

Abstract The sol–gel dip coating technique was used to manufacture undoped and Barium doped zinc oxide thin films. Doping is extensively used to refine semiconductor properties. Without and with varying ratios of Ba 1–9 wt% dopant, ZnO thin films have been manufactured. The effect of Ba on the dielectric, structural, antibacterial, optical and morphological characteristics of ZnO was investigated. The optical properties demonstrate that the bandgap of the pure ZnO thin film is higher than that of Ba-doped ZnO films, which is beneficial for improving solar cell performance. According to the XRD data, all films of ZnO have hexagonal wurtzite structures According to XRD structural analysis; the incorporation of Ba lowers the crystallinity of ZnO thin films by reducing the crystallite size. The Ba doping changes the surface roughness and morphology. The hopping process defines the dielectric characteristics that follow Koop’s theory as well as the Maxwell–Wagner model. A lower dielectric constant makes it ideal for high-frequency devices. These films exhibit ferromagnetism. Barium-doped zinc oxide photocatalyst could successfully decompose methylene blue dye by making it suitable for wastewater treatment. Ba doping effectively kills both gram-negative and gram-positive bacteria. They have antimicrobial applications in the food industry and biomedicine.