Improvement of the Optical Properties of Zn-Doped MnO Nanocomposites Thin films

Nanostructured thin films of MnO, Mn:5%ZnO, and Mn:10%ZnO were deposited through the process of chemical spray pyrolysis (CSP) on glass substrates. To examine the structural and optical characteristics, various analytical techniques such as XRD, FE-SEM, and UV-VIS spectrophotometer were employed to characterize the thin films that were synthesized. X-ray diffraction demonstrated that deposition conditions affected crystallite size in these thin films, and the Scherrer equation showed that the average crystalline size increased with ZnO-doped manganese solution. The linear plot shows a positive slope (0.0004 and 0.001) for all samples MnO and Mn:10%ZnO, which have a tensile strain and a lattice expansion in nano-tetragonal samples, except for Mn:5%ZnO, which has a negative slope (-0.0013). FE-SEM images showed that the particle size for all samples was 35.7, 56.9, and 23.6 nm for MnO, Mn:5%ZnO, and Mn:10%ZnO nanostructured thin films, respectively, which matches XRD analyses. Within the range of the visible spectrum, the optimal average transmission value falls between 20% and 60%. The Tauc relation was used to determine the optical energy-band gap (Eg), which exhibited an increase from 2.93 eV to 3.11 eV upon ZnO doping. The Mn: ZnO thin films show versatile optical properties that are essential for various applications, including transparent electromagnetic interference (EMI) shielding materials, photovoltaic, and solar cells. The Mn:5%ZnO sample produced an optical band gap of 3.06 eV, which was lower than the optical band gap of 3.37 eV observed in pure ZnO films.