Document Type : Original Article
Spectroscopy Dept, NRC
To produce transparent thin films of undoped and Fe-loaded zinc oxide (ZnO) referred to as ZTF, Z (15-30 %F), the current study utilizes a modified sol-gel spin coating method (Zn-Fe). Both undoped and Fe-loaded ZnO thin films were annealed at 5000C for 2 hours. The morphologies and the structural characteristics of pure and doped ZnO thin films were studied. The structure of the resulting films was investigated using X-ray diffraction (XRD) spectra, revealing good crystal quality and a pure hexagonal wurtzite ZnO structure free of Fe-associated phases. The crystallite size of undoped ZnO thin film is 10.47 nm, and it decreases when the Fe content is increased to 25 mol. %, then it returns to increase at 30 mol. %, giving the following values 10.37, 9.66, 8.26, and 15.59 nm, respectively. Plane images were taken with a field emission scanning electron microscope (FESEM) revealing spherical particles and smooth surface shapes in the ZnO thin film, whilst Fe-loaded ZnO films have a uniform and compact morphology. The Laser-based Raman micro-spectroscopy presents the homogenous distribution of the iron oxide. The optical properties of thin films, such as transmittance (T %) and the absorption coefficient obtained from the absorbance spectrum were determined using UV/vis spectroscopy. The T% of ZTF film exhibited an average value of nearly 97% and reduced when the Fe concentrations were increased. ZTF, Z15FTF, Z20FTF, Z25FTF, and Z30FTF have energy band gaps of 3.138, 3.234, 3.240, 3.242, 2.936eV, respectively.