Effect of seed layers (Al, Ti) on optical and morphology of Fe-doped ZnO thin film nanowires grown on Si substrate via electron beam evaporation

The effects of Al and Ti seed layers were studied for undoped and Fe-doped ZnO thin films deposited on n-type Si substrates by electron beam (e-beam) evaporation. The films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The films grown on seed layers showed wurtzite hexagonal crystal nanorod and nanowire structures. A higher angle phase shift was observed in the doped thin films compared to the pristine ZnO films. Microstructural studies confirmed the growth of nanorods and nanowires with average widths of ~32 nm and ~8-29 nm, respectively. The nanostructures were denser and more crystalline on the Al seed layer than on the Ti seed layer for the doped thin films. However, in the undoped thin films, a more crystalline nature was observed on the Ti seeded layer than the Al seeded layer.