Systematic Investigation of Structural, Morphological and Optical Properties of Fe Doped ZnO Nanorods and Its Nanocomposite with Graphite Oxide

This study reports the synthesis, structural, morphological and optical properties of the semiconducting materials of pristine ZnO nanorods (NRs), Fe doped ZnO (Zn_1−xFe_xO) NRs, graphite oxide (GO) nanoparticles (NPs) and Zn_1−xFe_xO/GO nanocomposite (NCs) that may be promising candidate for semi-transparent solar cells and metamaterials based applications. The sol–gel method has been employed because of its ease and efficiency to synthesize NRs with nearly uniform sizes at room temperature. The hexagonal wurtzite structure and polycrystalline nature of ZnO based samples and hexagonal structure and crystalline nature of GO sample have been confirmed by x-ray diffraction (XRD). The occurrence of characteristic XRD peak at 23.85° and the absorption peak at 274 nm confirms the presence of GO in the nanocomposite material. In the absorbance spectra the maxima shifts from 377 to 366 nm as one goes from pristine ZnO NRs to Zn_1−xFe_xO/GO NCs material, which indicates a blue shift in the absorption edge. The optical band gap values using Tauc’s extrapolation method are 2.91, 2.97, 2.76 and 2.52 eV for pristine ZnO NRs, Fe doped ZnO NRs, GO NPs and Zn_1−xFe_xO/GO nanocomposite respectively. All the optical parameters, extinction coefficient (k) and refractive index (n) values have been calculated for the wavelength range of 200-800 nm using absorption and transmission spectra. Wemple–Di domenico single oscillator model is used in the calculation of static refractive index and optical bandgap of synthesized materials. The dielectric constant values show the epsilon negative material behaviour of synthesized samples, which can be employed in various metamaterials’ based applications.