A comparative study on ZnS thin films grown by thermal evaporation and magnetron sputtering

Thin films of ZnS were deposited on cleaned soda lime glass substrates by using thermal evaporation and RF magnetron sputtering techniques. For thermal evaporation, a boat-substrate distance of 4cm was maintained. In case of sputtering, the deposition was done at a substrate temperature of 400°C. A comparative study of the structural and optical properties of the thin films prepared from both the processes was carried out by means of XRD, AFM and UV-Vis spectrometry. From the XRD analysis, it is found that the films grown from both the processes are polycystalline in nature having the (111) preferential orientation. The variations of crystallite grain size, lattice constant, microstrain and dislocation densities are also observed for the films. The AFM results show that, the average roughness of the sputtered films are slightly lower than the thermally evaporated films. From the optical study, the bandgaps were found as 3.25eV and 3.8eV for the films deposited by thermal evaporation and sputtering techniques respectively.