Exploring the impact of variable sputtering power on the morphological, optoelectronic, and thermoelectric properties of Fe-ITO thin films

Abstract This study employs RF magnetron sputtering to prepare and pure thin films of indium tin oxide (ITO), exploring both its pure form and its augmentation with iron (Fe) doping. The influence of Fe on these films was thoroughly scrutinized using diverse characterization approaches, including thermoelectric evaluations, X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible spectroscopy, and Hall measurements. XRD confirmed the cubic crystal structure, while SEM imaging revealed a distinctive granular like arrangement. The optical results (Tauc plot) revealed a narrowed bandgap (3.80 eV–3.67 eV) and diminished optical transmission in the visible spectrum owing to Fe doping. Electrical analysis revealed enhanced carrier availability, yielding a significant drop in thin film resistivity to 4.7 × 10 −5 Ω cm at an Fe concentration of 50 W. However, a increased Fe content leads to increased carrier density and resistivity. The mobility decreases, and the Seebeck value diminishes with increasing carrier concentration and Fe content. Remarkably, at 20 W Fe power, the thermoelectric power factor peaks at 0.73, aligning with a resistivity of 7.18 × 10 −5 Ω cm. These compelling findings, spanning the optical, structural, electrical, and thermal dimensions, emphasize the prospective utility of these materials in thermoelectric and photovoltaic systems.