Effects of Varying Growth Temperature on Optical and Structural Properties of Iron-doped Zinc Oxide Nanoparticles

Abstract

Iron-doped zinc oxide nanoparticles (Fe: ZnO NPs) have gained attention in biomedical fields due to their tunable optical properties and potential as biomedical agents. However, the influence of growth temperature on their structural integrity and luminescence performance remains unexplored. This study investigated the effect of varying growth temperature on the structural and optical properties of Fe: ZnO NPs to optimize their performance for potential bioimaging applications. Fe: ZnO NPs were synthesized using the sol-gel technique at different growth temperatures room temperature (RT), 35°C, 45°C, 55°C, 65°C, 75°C, 85°C, 95°C) and their structural and optical characterization was carried out using X-ray diffractometer (XRD), photoluminescence (PL) spectroscopy, and Ultraviolet-Visible spectrometer (UV- Vis). XRD results confirmed the retention of a single-phase hexagonal wurtzite structure, and the slight shift in peaks showed the successful incorporation of Fe. Optical properties showed systematic absorbance modulation, a blue shift, and reduced optical bandgap (3.0 eV) at 65°C. PL revealed strong UV emission peaks in the 410-470 nm region, indicating enhanced near-band-edge (NBE) emission, which was optimized at 65°C and quenched at higher growth temperatures. Growth temperature at 65°C yields optimum optical and structural properties, therefore not only addressing the existing knowledge gap on temperature-dependent optimization of Fe: ZnO NPs for bioimaging but also establishing a foundation for future nanomedical applications of these NPs