Grown of ZnO based on nanostructure semiconductor thin films and fabrication of gas sensors

In present PhD. thesis study, the films of undoped and ZnO doped with Al, Cu and Sn dopants for various atomic ratios of 0.1%at., 0.5%at., 1%at., 2%at., 5%at. were prepared by the sol gel method. The films were grown by spin coating method. The crystal structures and surface morphologies of the films were investigated by X-ray diffraction technique, scanning electron microscopy (SEM) and atomic force microscopy. The XRD results indicate that undoped and doped ZnO films are polycrystalline with a hexagonal structure.The crystallite size and lattice constants of the films were calculated. The obtained crystallite size results suggest that the films are nanomaterials. The AFM results indicate that the films are formed from fibers having the nanoparticles. The optical band gaps of the films were determined by optical absorption method and the optical band gaps of the films were found in the range of 3.024 and 3.297 eV. The ammonium gas sensors were prepared using undoped and metal doped ZnO films. The sensitivity properties of the gas sensors were improved using Al, Cu and Sn dopants. The obtained gas sensor results suggest that the prepared gas sensors can be used for detection of ammonium gas.Key words: Gas sensors, Zinc oxide, Metal oxide Semiconductor