Effects of CdS substrates on the physical properties of polycrystalline CdTe films

In this study, CdS thin films were deposited by thermal evaporation, close spaced sublimations, and solution growth methods, respectively, and the effects of the deposition methods on the physical properties of polycrystalline CdS deposited on ITO/glass were investigated. In addition, the effects of variously deposited CdS on the physical properties of thermally evaporated CdTe were also investigated. XRD results showed that CdS thin films deposited by solution growth, thermal evaporation, and close spaced sublimation (CSS) had a hexagonal structure with a random orientation of, (002) and (103) preferred orientation, respectively. All of the CdTe thin films deposited on those CdS substrates had the same cubic zincblende structure, however, they showed a little different crystal orientation relationship depending on the underlying CdS deposition method. Cross-sectional TEM showed that CdTe grain sizes of the furnace annealed CdTe grown on the CSS-CdS was the smallest among the furnace annealed CdTe thin films deposited on the variously prepared CdS substrates.