The present work provides a mathematical formulation for the optical energy gaprefractive
index relations of Fe layer with different thickness, inserted between
two layers of ZnO in the form of ZnO/Fe/ZnO thin film system. The thin films
having a multilayer of ZnO/Fe/ZnO have been grown on glass substrates, using
atomic layer deposition and DC magnetron sputtering. The crystalline structure of
the multilayer thin films was carried out by the X-Ray diffraction while the thickness
data and the quality of the layers were checked by using a prepared lamella
for each sample using focused ion beam (FIB). The extinction coefficient (k) of the
thin film samples was used to calculate the energy band gap (Eg). An explanation
for the dependence of Fe interlayer thickness (20, 40, 60 and 80nm) between upper
and lower layer of ZnO(80nm) on the optical energy gap and refractive index (n)
of the thin film samples and their relationship are presented and discussed using
different theories. With increasing the Fe interlayer thickness, the evaluated band
gap showed a decrease from 3.77eV to 3.43 eV, while the calculated refractive
index was found to increase from 2.20 to 2.27. The optical conductivity, optical
dielectric constant, dielectric susceptibility, electronic polarizability, electronegativity,
optical basicity and metallization criterion were obtained by several calculations
based on the refractive index. By fixing the ZnO thickness and varying the
Fe thickness, we can isolate the effects of Fe thickness on the optical properties
of ZnO/Fe/ZnO system. The fixed thickness of ZnO enable direct comparison of
the optical properties and related parameters across different Fe thickness and
hence enabling the design of materials with specific potential applications. Further
derivations based on the energy gap – refractive index relations discussed
in the context, indicates that the insertion of a metallic layer into oxide layer have
high potential that could enhance the quality of remarkable optical properties
of ZnO thin film, to be applied for memories applications and allows the performance
of the devices, to be optimized.in many industrial and consumer products. |
