Optimization of the Properties of ZnO Films Produced by the SILAR Technique

Zinc oxide (ZnO) is a promising semiconductor material for optical and gas sensors. This study examines the influence of film thickness and solvent choice on the performance of ZnO thin films generated by SILAR at room temperature and atmospheric pressure. Ethanol and distilled water (DW) were used as solvents. Thin films of varying thicknesses were analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM) atomic force microscopy (AFM), and Hall effect measurements to evaluate their morphology, crystal structure, and optical and electrical properties. X-ray diffraction analysis showed that films created using ethanol or DW have a hexagonal ZnO structure with a predominant growth orientation along the (002) plane. Films prepared with ethanol exhibited crystallinity comparable to films prepared with DW. ZnO films prepared with ethanol showed low resistivity (10^-2 Ω cm) and high electron mobility (750 cm²/Vs). This highlights the potential of the SILAR method using ethanol to create high-quality ZnO thin films suitable for various applications. Thus, the study highlights the importance of thickness and solvent selection in the SILAR deposition process to optimize the properties of ZnO thin films for optical and gas sensors.