Structural, nonlinear optical and antimicrobial properties of sol-gel derived, Fe-doped CuO thin films

Undoped and Fe-doped CuO thin films with different weight ratios (3, 6, and 9 wt.% of Fe) were deposited onto glass substrates using the sol-gel spin coating technique. X-ray diffraction analysis of these samples indicated that all the films were polycrystalline, and crystallite size decreased with doping concentration. As revealed by scanning electron microscopy, Fe doping increased average particle size and improved size distribution in films. The bandgap of undoped CuO thin film was tuned from 3.48 to 2.79 by the addition of 9 wt.% Fe, and reasonable explanations have been presented. Optical parameters, such as refractive index, extinction coefficient, dielectric constant, and optical conductivity, were calculated for optoelectronic applications. Finally, antimicrobial properties were measured for their possibility to be used as disinfectants, and the antifungal activity of Fe-doped CuO thin films was shown to be more effective.