Performance of copper doped zinc oxide nanoparticles synthesized through solid state reaction route for humidity sensing device

In the current study, the moisture-sensing properties of three Copper (1%) doped Zinc Oxide nanomaterials, CZ-1, CZ-2, and CZ-3, are examined. These substances were created by solid-state interactions involving Cu2O and ZnO, CuO and ZnO, and, separately, Cu and ZnO. After four hours of annealing at 700°C for each of the three pellet samples, humidity-sensing tests were conducted. Throughout the whole range of relative humidity percent (15-90%RH) at room temperature, it was observed that the electrical resistance of all three nanomaterials reduced steadily. Powder x-ray diffractometer and scanning electron microscopy analyses were performed on the nanomaterial pellets to determine their crystallinity, structural phases (gross crystal structure), and surface morphology. Both the Scherer's approach and the Williamson and Hall's method were used to determine the crystallite size of the three samples, CZ-1, CZ-2, and CZ-3. The CZ-3 sample annealed at 700°C had the lowest crystallite size (36 nm) and the highest humidity sensitivity of the three samples.