Production and characterization of MgF2 based anti-reflective thin film coatings on CdS

It is known that thin film coating studies are used to prevent reflection losses in optoelectronic applications. In this thesis, it is aimed to develope anti-reflective thin film structures by using materials with different refractive indices. For this purpose, Cadmium Sulfide (CdS) thin film, an II-IV group semiconductor compound, and Magnesium Fluoride (MgF2) thin film, an alkaline earth metal fluoride, are grown on glass substrates using the Physical Vapor Deposition (PVD) method. In order to determine the anti-reflective properties of the thin film structures, MgF2, which has a lower refractive index than the glass substrate, is preferred as the coating material on CdS thin film, which has a higher refractive index than the glass substrate. The structural, optical and morphological properties of double-layer anti-reflective thin film coatings produced in different thicknesses are investigated with X-Ray Diffraction (XRD), UV-vis spectrophotometer, Energy Dispersive X-Ray Spectroscopy (EDS) and Field Emission Scanning Electron Microscope (FESEM), respectively. As a result of the analyzes, it is observed that MgF2 structure grown as a second layer on CdS thin films is reduced optical reflection losses up to 30% in the visible region and accordingly increased the transmittance. Moreover, the structures are annealed separately and it is investigated whether or not annealing has an effect on reducing optical losses.