On the substrate heating effects on structural, mechanical and linear/ non-linear optical properties of Ag-Mn co-doped ZnO thin films

Optimization of the physical properties of ZnO thin films doped with different elements opens new opportunities for the application of these materials in different fields. Consequently, it is crucial to thoroughly explore the correlation of their structural, mechanical, and optical properties. In this paper, pure and Ag-Mn co-doped ZnO thin films were deposited by rapid thermal evaporation (RTE) method on glass substrates with the same Ag (5%)Mn (5%) content at different substrate temperatures (room temperature, 200 C and 400 C). Subsequently, the samples were then annealed at 400 C for 1 h. The prepared thin films were characterized by many techniques including XRD, XPS, SEM, EDS, Nanoindentation and UV-Vis-NIR spectroscopy. XRD analysis showed that the annealed layers have hexagonal wurtzite structure and the crystallinity rises as the substrate temperature increases. The elemental analysis of the films investigated by XPS and EDS which revealed the presence of C, Zn, Ag, Mn and O atoms for all layers. The morphological aspect performed by SEM revealed the apparition of nanoparticles of silver and ZnO. Nanoindentation measurements showed that the hardness increases from 9.43 to 12.44 GPa. The optical transmission of the films decreases with doping and with substrate heating, reaching 70-81 %. These variations are due to the structural and morphological changes related to the effect of co-doping and substrate heating.