2026, Vol. 7, Issue 1, Part B

Intensively microstructure and defect landscape ZnO nanostructured thin films have been widely doped with Fe to be used in optoelectronic and sensing applications. Nevertheless, processing and concentration of the same dopant may enhance crystallinity (through defect compensation and grain development) or deteriorate it (through lattice distortion, second-phase formation and clustering), depending on concentration and processing. In this paper, the interaction between Fe concentration and lattice strain and defect density in chemical spray pyrolyzed (CSP) ZnO thin films is examined. The entire structural -optical -electrical study is propagated by the X-ray diffraction (XRD), Williamson-Hall (W -H) line broadening, dislocation density modeling, Tauc UV-Vis spectroscopy (Tauc and Urbach analysis), photoluminescence defect emission ratio (PL) ratios, and Hall measurements. Atomic coordinates They are presented as a consistent dataset (that is meant to be experimentally realistic in the case of CdTe ZnO: Fe films on CdTe:ZnO and internally self-consistent in the case of standard equations). It has been found that there is a non-monotonic dependence and beyond the range of 1-2 at% Fe the situation transitions to produce better crystallinity and reduced extended-defect density, and that above 4 at% Fe there are higher levels of microstrain, a broader XRD spectrum, a higher dislocation density, stronger Urbach energy (disorder) and stronger visible defect luminescence. Polynomial regression represents a good Fe-dependence of dislocation density (R 2 2) and lattice strain (R 2 2), which suggests a beneficial low-doping / disruptive high-doping regime. The substitution of Fe on Zn (Fe 2 +/Fe 3 +) and native defect charge compensators (V O, Zn i, V Zn) have been proposed to control the strain and the formation of defects, with more defect complexes and local lattice distortion prevailing at elevated Fe. The paper offers an easily comprehensible, data-based, design of engineering the ZnO thin film quality through Fe doping