Fabrication and the impact of Fe and Al substitution on structural, morphological, vibrational and optical properties of Fe: Al co-doping zinc oxide nanostructured thin films developed by Arduino based spin coating device

Abstract

Iron (Fe) and Aluminum (Al) co-doping nanostructured Zinc oxide (ZnO) films were fabricated at various Fe doping concentrations (3 wt%, 5 wt%, and 7 wt%) using the Arduino based spin coating device. In this report, the influence of Fe doping concentration on crystal microstructure and optical properties of Fe: Al co-doping ZnO films were investigated. The structural and optical characteristics of the material were determined using x-ray XRD and UV–VIS spectroscopy. SEM-EDS analysis was used to determine the surface morphology and elemental composition. XRD analysis confirmed the existence of a polycrystalline hexagonal ZnO phase. When the Fe content was increased, it was found that the crystalline quality of the deposited films deteriorated. The optical spectra revealed a transparency range of 85% to 75%. The film with Fe 7 wt% and Al wt3% dopant concentrations exhibited an optical band gap of 3.30 eV. Non-linear optical properties such as non-linear refractive index, non-linear susceptibility using the linear refractive index and energy gap were calculated. The linear refractive index was determined using a variety of models. The non-linear optical properties observed demonstrated a significant dependency on dopant concentrations. The non-linear refractive index and non-linear susceptibilities of the deposited co-doping films are 4.12×10-11-4.67×10-11esu and 2.54×10-12-2.92×10-12esu respectively. SEM analysis of all films demonstrates the growth of nanoscale crystal grains. FTIR spectroscopy verified the zinc oxide metallic bond formation in (Fe, Al) co-doping ZnO thin films.