Impact of Zn content in tailoring the properties of NiZnO alloy films grown by spray pyrolysis

The growing demand for efficient ultraviolet (UV) radiation detection has necessitated the exploration of novel material systems with enhanced performance. In this study, zinc (Zn) was systematically incorporated into nickel oxide (NiO) to synthesize NiZnO alloy thin films via the spray pyrolysis technique. The influence of Zn incorporation on the structural, optical, and electrical properties of the films was investigated through comprehensive characterization techniques. X-ray diffraction (XRD) and morphological analysis revealed a significant improvement in crystallite size and surface morphology with increasing Zn content. Optical studies indicated a reduction in bandgap energy from 3.5 eV to 3.2 eV, while Raman spectroscopy confirmed the successful substitution of Zn within the NiO lattice. Room-temperature photoluminescence (PL) analysis provided insights into defect states within the system. Upon exposure to UV light at 395 nm, an increase in photocurrent was observed, attributed to the generation of additional charge carriers. Hall effect measurements, conducted before and after Zn incorporation, demonstrated a transition from p-type to n-type conductivity when Zn concentration exceeded 60 %. These findings underscore the tunability of NiO thin films through Zn substitution, offering potential advancements in UV photodetector applications.