The growth of doped ZnO thin films by the silar method and investigation of structural, optical and electrical properties

In recent years, the production and characterization of nano-sized structures and thin films of semiconductor materials have become significant subjects of research and application across various fields of science and technology. One of these areas of interest is the synthesis and characterization of zinc oxide (ZnO) thin films. ZnO has garnered substantial attention due to being a semiconductor material with a wide energy bandgap and possessing unique electrical, optical, and structural properties. Additionally, these films offer potential for a range of applications, especially in areas such as semiconductor devices, optoelectronic devices, solar cells, and sensors. In this thesis study, structural and electrical characterization was conducted on undoped ZnO and Sn- and Cu-doped ZnO thin films grown on ITO substrates using the SILAR method. Thin film samples were obtained by performing 40 SILAR cycles and subsequently annealed at 300 °C. The structural, surface morphological, and electrical properties of the produced undoped ZnO and Sn- and Cu-doped ZnO thin films were examined. SEM analysis revealed that the surface morphology of the undoped ZnO thin film sample exhibited the formation of spherical structures with some voids on the substrate. The Sn-doped ZnO thin film sample exhibited growth in the form of nano-flower structures on the ITO substrate. The formed structures formed fractured layers in certain areas while voids were present in other regions. The surface morphology of the Cu-doped ZnO thin film sample indicated the formation of a flat and relatively thicker layer on the ITO substrate, exhibiting fractures that created voids. Electrical analysis (I-V) showed positive results of doping with different elements. This suggests that the produced thin films could be used as transparent conducting films (TCO) due to their low resistance.